Drive apparatus and automobile

As a control of an inverter, a first pulse width modulation control switches a plurality of switching elements by generating a first pulse width modulation signal of the switching elements, and a second pulse width modulation control switches the switching elements by generating a second pulse width modulation signal of the switching elements based on a voltage modulation rate, a voltage phase, and the number of pulses per unit cycle of an electrical angle of the motor based on the torque command and has a smaller number of switchings of the switching elements than the first pulse width modulation control. The first pulse width modulation control and the second pulse width modulation control are executed in a switched manner. Execution of the second pulse width modulation control as the control of the inverter is restricted when the quietness is needed, compared with when the quietness is not needed.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2016-205428 filed on Oct. 19, 2016 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a drive apparatus and an automobile, and specifically relates to a drive apparatus including a motor, an inverter, and an electricity storing device and an automobile in which the drive apparatus is mounted.

2. Description of Related Art

In the related art, suggested is a drive apparatus that includes an electric motor and an electric power converting device having an inverter circuit that drives the electric motor by switching of a plurality of switching elements. In the drive apparatus, switching of the switching elements is performed by generating pulse signals of the switching elements based on the number of pulses of one electric cycle of the electric motor and the modulation rate of a voltage and a voltage phase that are based on a torque command of the electric motor (refer to, for example, Japanese Unexamined Patent Application Publication No. 2013-162660 (JP 2013-162660 A)). Loss in the drive apparatus as a whole is decreased by generating the pulse signals in the drive apparatus such that electric power loss in the electric power converting device and the electric motor is minimized based on the number of pulses, the modulation rate, and the voltage phase.

SUMMARY

The method of generating and outputting the pulse signals to the electric power converting device in the drive apparatus is considered to have a smaller number of switchings of the switching elements than a method of generating and outputting the pulse signals to the electric power converting device by comparing a voltage command of each of the phases of the electric motor with a carrier wave voltage. However, when the number of switchings of the switching elements is small, noise (electromagnetic noise) due to switching of the switching elements is likely to be significant. Thus, quietness when needed may not be satisfied.

The present disclosure provides a drive apparatus and an automobile more sufficiently satisfying a need for quietness.

Aspects of the present disclosure are as follows.

A first aspect of the present disclosure relates to a drive apparatus including a motor, an inverter configured to drive the motor by switching of a plurality of switching elements, an electricity storing device configured to exchange electric power with the motor through the inverter, and an electronic control unit. The electronic control unit controls the inverter by switching between a first pulse width modulation (PWM) control and a second PWM control. The first PWM control switches the switching elements by generating a first PWM signal of the switching elements by comparison of a voltage command of each phase based on a torque command of the motor with a carrier wave voltage. The second PWM control switches the switching elements by generating a second PWM signal of the switching elements based on a voltage modulation rate, a voltage phase, and the number of pulses per unit cycle of an electrical angle of the motor based on the torque command. The number of switchings of the switching elements in the second PWM control is smaller than the number of switchings of the switching elements in the first PWM control. When quietness is needed in the drive apparatus, execution of the second PWM control as the control of the inverter is restricted, compared with when the quietness is not needed.

The drive apparatus according to the first aspect executes the first PWM control and the second PWM control in a switched manner as the control of the inverter. The first PWM control switches the switching elements by generating the first PWM signal of the switching elements by comparison of the voltage command of each phase based on the torque command of the motor with the carrier wave voltage. The second PWM control switches the switching elements by generating the second PWM signal of the switching elements based on the voltage modulation rate, the voltage phase, and the number of pulses per unit cycle of the electrical angle of the motor based on the torque command. The second PWM control has a smaller number of switchings of the switching elements than the first PWM control. When the quietness is needed, execution of the second PWM control as the control of the inverter is restricted, compared with when the quietness is not needed. The second PWM control has a smaller number of switchings of the switching elements than the first PWM control and thus, is likely to have more significant noise (electromagnetic noise) due to switching of the switching elements. Accordingly, when the quietness is needed, execution of the second PWM control as the control of the inverter is restricted, compared with when the quietness is not needed. Thus, a need for the quietness can be more sufficiently satisfied. Examples of “restricting execution of the second PWM control” include reducing an execution region of the second PWM control and preventing execution of the second PWM control.

In the drive apparatus according to the first aspect, the electronic control unit may permit execution of the second PWM control as the control of the inverter when the quietness is not needed, and prevent execution of the second PWM control as the control of the inverter when the quietness is needed. By doing so, a determination as to whether or not to execute or prevent the second PWM control can be made in accordance with whether or not the quietness is needed. In this case, the electronic control unit may execute the second PWM control as the control of the inverter when execution of the second PWM control as the control of the inverter is permitted with a target operating point of the motor being within a predetermined region, and execute the first PWM control as the control of the inverter when execution of the second PWM control as the control of the inverter is permitted with the target operating point being outside the predetermined region, and when execution of the second PWM control as the control of the inverter is prevented. By doing so, a determination can be made as to whether execution of the second PWM control is permitted or prevented and which of the first PWM control and the second PWM control is to be executed as the control of the inverter in accordance with the target operating point of the motor.

In the drive apparatus according to the first aspect, the second PWM control may generate the second PWM signal of the switching elements such that a harmonic component of a desired order is reduced and that total loss of loss in the motor and loss in the inverter is reduced, compared with the first PWM control. By doing so, a reduction in the harmonic component of the desired order and a reduction in the total loss can be achieved when the second PWM control is executed, compared with when the first PWM control is executed. The “desired order” may be a specific order or may be a comparatively wide range of orders of a low order to a high order.

A second aspect of the present disclosure relates to an automobile including the drive apparatus according to the aspect and drive wheels driven by being connected to the motor. The electronic control unit is configured to determine that the quietness is needed, when a vehicle speed of the automobile is lower than or equal to a predetermined vehicle speed. When the vehicle speed is comparatively low, road noise is smaller than when the vehicle speed is comparatively high, and electromagnetic noise is unlikely to be mixed with road noise. Thus, a driver or the like is considered likely to perceive electromagnetic noise. Accordingly, when the vehicle speed is lower than or equal to the predetermined vehicle speed, a determination is made that the quietness is needed inside the vehicle, and execution of the second PWM control as the control of the inverter is restricted. Thus, a need for the quietness inside the vehicle can be more sufficiently satisfied. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

A third aspect of the present disclosure relates to an automobile including the drive apparatus according to the aspect, drive wheels driven by being connected to the motor, and an engine configured to output power for traveling to the drive wheels. The electronic control unit is configured to determine that the quietness is needed, when the automobile travels without operation of the engine. Engine sound is not generated when the automobile travels without operation of the engine. Thus, the driver or the like is considered more likely to perceive electromagnetic noise than when the automobile travels with operation of the engine. Accordingly, when the automobile travels without operation of the engine, a determination is made that the quietness is needed inside the vehicle, and execution of the second PWM control as the control of the inverter is restricted. Thus, a need for the quietness inside the vehicle can be more sufficiently satisfied. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

A fourth aspect of the present disclosure relates to an automobile including the drive apparatus according to the aspect and drive wheels driven by being connected to the motor. The electronic control unit is configured to determine that the quietness is needed, when the number of lanes in a current location of the automobile is smaller than or equal to a predetermined number of lanes. When the number of lanes is small, the width of the road is smaller than when the number of lanes is great, and a pedestrian or the like around the automobile is considered more likely to perceive electromagnetic noise. Accordingly, when the number of lanes in the current location of the automobile is smaller than or equal to the predetermined number of lanes, a determination is made that the quietness is needed outside the vehicle, and execution of the second PWM control as the control of the inverter is restricted. Thus, a need for the quietness outside the vehicle can be more sufficiently satisfied. Specifically, the pedestrian or the like around the automobile can have more sufficiently reduced perception of electromagnetic noise.

A fifth aspect of the present disclosure relates to an automobile including the drive apparatus according to the aspect and drive wheels driven by being connected to the motor, in which the electronic control unit is configured to determine that the quietness is needed, at night. At night, the pedestrian or the like around the automobile is considered more likely to perceive electromagnetic noise than at other than night (at day). Accordingly, at night, a determination is made that the quietness is needed outside the vehicle, and execution of the second PWM control as the control of the inverter is restricted. Thus, a need for the quietness outside the vehicle can be more sufficiently satisfied. Specifically, the pedestrian or the like around the automobile can have more sufficiently reduced perception of electromagnetic noise.

A sixth aspect of the present disclosure relates to an automobile including the drive apparatus according to the aspect, drive wheels driven by being connected to the motor, an engine, a power generator configured to generate electric power by using power from the engine, and a power generator inverter configured to drive the power generator by switching of a plurality of second switching elements. The electricity storing device exchanges electric power with the motor and the power generator through the inverter and the power generator inverter. The electronic control unit is configured to control the engine and the power generator inverter such that the electricity storing device is charged with electric power generated by the power generator using power from the engine, when an electricity storage ratio of the electricity storing device is lower than or equal to a predetermined ratio at a standstill of the automobile. The electronic control unit is configured to control the power generator inverter by switching between the first PWM control and the second PWM control. The electronic control unit determines that the quietness is needed, when the automobile is at a standstill. When the quietness is needed, the electronic control unit is configured to restrict execution of the second PWM control as the controls of the inverter and the power generator inverter, compared with when the quietness is not needed. Since road noise is not generated at a standstill, the driver or the like at a standstill is considered more likely to perceive electromagnetic noise than during traveling. Accordingly, when the automobile is at a standstill, a determination is made that the quietness is needed inside the vehicle, and execution of the second PWM control as the controls of the inverter and the power generator inverter is restricted. Thus, a need for the quietness inside the vehicle can be more sufficiently satisfied. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1is a configuration diagram illustrating a schematic configuration of a hybrid automobile20in which a drive apparatus as the embodiment of the present disclosure is mounted.FIG. 2is a configuration diagram illustrating a schematic configuration of an electric drive system including motors MG1, MG2. As illustrated inFIG. 1, the hybrid automobile20of the embodiment includes an engine22, a planetary gear30, the motors MG1, MG2, inverters41,42, a battery50as an electricity storing device, a step-up converter55, a system main relay56, a navigation device90, and a hybrid electronic control unit (hereinafter, referred to as an “HVECU”)70.

The engine22is configured as an internal combustion engine that outputs power with gasoline, diesel, or the like as fuel. Operation of the engine22is controlled by an engine electronic control unit (hereinafter, referred to as an “engine ECU”)24.

The engine ECU24, though not illustrated, is configured as a microprocessor mainly having a CPU and includes a ROM storing a processing program, a RAM temporarily storing data, input and output ports, and a communication port in addition to the CPU. Signals from various sensors controlling operation of the engine22, for example, a crank angle θcr from a crank position sensor23detecting a rotation position of a crankshaft26of the engine22, are input into the engine ECU24from the input port. Various control signals that control operation of the engine22are output from the engine ECU24through the output port. The engine ECU24is connected to the HVECU70through the communication port. The engine ECU24calculates the number of rotations Ne of the engine22based on the crank angle θcr from the crank position sensor23.

The planetary gear30is configured as a single pinion planetary gear mechanism. A rotor of the motor MG1is connected to a sun gear of the planetary gear30. A drive shaft36that is connected to drive wheels39a,39bthrough a differential gear38is connected to a ring gear of the planetary gear30. The crankshaft26of the engine22is connected to a carrier of the planetary gear30through a damper28.

The motor MG1is configured as a synchronous power generating electric motor having the rotor in which a permanent magnet is embedded and a stator on which three-phase coils are wound. The rotor of the motor MG1is connected to the sun gear of the planetary gear30as described above. The motor MG2, in the same manner as the motor MG1, is configured as a synchronous power generating electric motor having a rotor in which a permanent magnet is embedded and a stator on which three-phase coils are wounded. The rotor of the motor MG2is connected to the drive shaft36.

As illustrated inFIG. 2, the inverter41is connected to a high voltage side electric power line54a. The inverter41has six transistors T11to T16and six diodes D11to D16that are connected in parallel to the transistors T11to T16in the reverse direction. The transistors T11to T16are disposed in pairs of two as a source side and a sink side respectively for a positive pole side line and a negative pole side line of the high voltage side electric power line54a. The three-phase coils (a U phase, a V phase, and a W phase) of the motor MG1are respectively connected to connection points between the transistor pairs of the transistors T11to T16. Accordingly, when a voltage is applied to the inverter41, the motor electronic control unit (hereinafter, referred to as a “motor ECU”)40adjusts the proportions of ON times of the pairs of the transistors T11to T16, thereby forming a rotating magnetic field in the three-phase coils and rotationally driving the motor MG1. The inverter42, in the same manner as the inverter41, is connected to the high voltage side electric power line54aand has six transistors T21to T26and six diodes D21to D26. When a voltage is applied to the inverter42, the motor ECU40adjusts the proportions of ON times of the pairs of the transistors T21to T26, thereby forming a rotating magnetic field in the three-phase coils and rotationally driving the motor MG2.

The step-up converter55is connected to the high voltage side electric power line54ato which the inverters41,42are connected and to a low voltage side electric power line54bto which the battery50is connected. The step-up converter55has two transistors T31, T32, two diodes D31, D32connected in parallel to the transistors T31, T32in the reverse direction, and a reactor L. The transistor T31is connected to the positive pole side line of the high voltage side electric power line54a. The transistor T32is connected to the transistor T31and negative pole side lines of the high voltage side electric power line54aand the low voltage side electric power line54b. The reactor L is connected to a connection point between the transistors T31, T32and to a positive pole side line of the low voltage side electric power line54b. By the motor ECU40adjusting the proportions of ON times of the transistors T31, T32, the step-up converter55steps up and supplies power of the low voltage side electric power line54bto the high voltage side electric power line54aor steps down and supplies power of the high voltage side electric power line54ato the low voltage side electric power line54b. A smoothing capacitor57is attached to the positive pole side line and the negative pole side line of the high voltage side electric power line54a. A smoothing capacitor58is attached to the positive pole side line and the negative pole side line of the low voltage side electric power line54b.

The motor ECU40, though not illustrated, is configured as a microprocessor mainly having a CPU and includes a ROM storing a processing program, a RAM temporarily storing data, input and output ports, and a communication port in addition to the CPU. As illustrated inFIG. 1, signals from various sensors controlling driving of the motors MG1, MG2or the step-up converter55are input into the motor ECU40through the input port. Examples of the signals input into the motor ECU40include rotation positions θm1, θm2from rotation position detecting sensors (for example, resolvers)43,44that detect rotation positions of the rotors of the motors MG1, MG2, and phase currents Iu1, Iv1, Iu2, Iv2from current sensors45u,45v,46u,46vthat detect currents flowing in each of the phases of the motors MG1, MG2. In addition, examples of the signals include a voltage VH of the capacitor57(the voltage of the high voltage side electric power line54a) from a voltage sensor57aattached between terminals of the capacitor57, a voltage VL of the capacitor58(the voltage of the low voltage side electric power line54b) from a voltage sensor58aattached between terminals of the capacitor58, and a current IL from a current sensor55aattached to a terminal of the reactor L, the current IL flowing in the reactor L. Switching control signals for the transistors T11to T16, T21to T26of the inverters41,42, switching control signals for the transistors T31, T32of the step-up converter55, and the like are output from the motor ECU40through the output port. The motor ECU40is connected to the HVECU70through the communication port. The motor ECU40calculates electrical angles θe1, θe2and numbers of rotations Nm1, Nm2of the motors MG1, MG2based on the rotation positions θm1, θm2of the rotors of the motors MG1, MG2from the rotation position detecting sensors43,44.

The battery50is configured as, for example, a secondary lithium-ion battery or a secondary nickel-hydrogen battery and is connected to the low voltage side electric power line54b. The battery50is managed by a battery electronic control unit (hereinafter, referred to as a “battery ECU”)52.

The battery ECU52, though not illustrated, is configured as a microprocessor mainly having a CPU and includes a ROM storing a processing program, a RAM temporarily storing data, input and output ports, and a communication port in addition to the CPU. Signals from various sensors managing the battery50are input into the battery ECU52through the input port. Examples of the signals input into the battery ECU52include a voltage Vb from a voltage sensor51adisposed between terminals of the battery50, a current Ib from a current sensor51battached to an output terminal of the battery50, and a temperature Tb from a temperature sensor51cattached to the battery50. The battery ECU52is connected to the HVECU70through the communication port. The battery ECU52calculates an electricity storage ratio SOC based on the cumulative value of the battery current Ib from the current sensor51b. The electricity storage ratio SOC is the ratio of electric power discharge capacity of the battery50to the total capacity of the battery50.

The system main relay56is disposed on the battery50side of the low voltage side electric power line54bfrom the capacitor58. The system main relay56is controlled to be switched ON and OFF by the HVECU70, thereby connecting and disconnecting the battery50and the step-up converter55.

The navigation device90includes a main body, a GPS antenna, and a touch panel display. The main body incorporates a storage medium such as a hard disk that stores map information and the like, and a control unit that has input and output ports, a communication port, and the like. The GPS antenna receives information related to the current location of the automobile. The touch panel display displays various types of information such as information related to the current location of the automobile and a travel route to a destination and can receive various instructions from an operator. The map information as a database stores service information (for example, tourism information, parking lots, and charging stations), road information per predetermined travel section (for example, between traffic lights or between intersections), and the like. The road information includes distance information, width information, information as to the number of lanes, area information (an urban area or a suburb), type information (a typical road or a highway), gradient information, legal speed information, the number of traffic lights, and the like. When a destination is set by the operator, the navigation device90finds a travel route from the current location of the automobile to the destination based on the map information and the current location and the destination of the automobile and provides route guidance by outputting the found travel route on a display. The navigation device90calculates route information (for example, a remaining distance Ln to the destination and a direction Dn to the destination) on the travel route. The navigation device90is connected to the HVECU70through the communication port.

The HVECU70, though not illustrated, is configured as a microprocessor mainly having a CPU and includes a ROM storing a processing program, a RAM temporarily storing data, input and output ports, and a communication port in addition to the CPU. Signals from various sensors are input into the HVECU70through the input port. Examples of the signals input into the HVECU70include an ignition signal from an ignition switch80and a shift position SP from a shift position sensor82that detects an operating position of a shift lever81. In addition, examples of the signals include an accelerator operation amount Acc from an accelerator pedal position sensor84that detects the amount of stepping on an accelerator pedal83, a brake pedal position BP from a brake pedal position sensor86that detects the amount of stepping on a brake pedal85, and a vehicle speed V from a vehicle speed sensor88. The shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like. As described above, the HVECU70is connected to the engine ECU24, the motor ECU40, the battery ECU52, and the navigation device90through the communication port.

Such configured hybrid automobile20of the embodiment travels in a hybrid travel (HV travel) mode of traveling along with operation of the engine22and an electric travel (EV travel) mode of traveling without operation of the engine22.

In the HV travel mode, the HVECU70sets a requested torque Td* for traveling (for the drive shaft36) based on the accelerator operation amount Acc and the vehicle speed V and calculates requested power Pd* for traveling (for the drive shaft36) by multiplying the set requested torque Td* by the number of rotations Nd of the drive shaft36(the number of rotations Nm2of the motor MG2). Next, the HVECU70sets requested power Pe* for the automobile (for the engine22) by subtracting a charge and discharge requested power Pb* (has a positive value at the time of discharge from the battery50) based on the electricity storage ratio SOC of the battery50from the requested power Pd*. Next, the HVECU70sets a target number of rotations Ne* and a target torque Te* of the engine22and torque commands Tm1*, Tm2* of the motors MG1, MG2such that the requested power Pe* is output from the engine22and that the requested torque Td* is output to the drive shaft36. Next, the HVECU70sets a target voltage VH* of the high voltage side electric power line54a(capacitor57) based on the torque commands Tm1*, Tm2* and the numbers of rotations Nm1, Nm2of the motors MG1, MG2. The HVECU70transmits the target number of rotations Ne* and the target torque Te* of the engine22to the engine ECU24and transmits the torque commands Tm1*, Tm2* of the motors MG1, MG2and the target voltage VH* of the high voltage side electric power line54ato the motor ECU40. The engine ECU24controls the amount of air intake, fuel injection, ignition, and the like of the engine22such that the engine22is operated based on the target number of rotations Ne* and the target torque Te*. The motor ECU40controls switching of the transistors T11to T16, T21to T26of the inverters41,42such that the motors MG1, MG2are driven by the torque commands Tm1*, Tm2*, and controls switching of the transistors T31, T32of the step-up converter55such that the voltage VH of the high voltage side electric power line54ais equal to the target voltage VH*.

In the EV travel mode, the HVECU70sets the requested torque Td* based on the accelerator operation amount Acc and the vehicle speed V, sets the torque command Tm1* of the motor MG1to a value of zero and sets the torque command Tm2* of the motor MG2such that the requested torque Td* is output to the drive shaft36, and sets the target voltage VH* of the high voltage side electric power line54abased on the torque commands Tm1*, Tm2* and the numbers of rotations Nm1, Nm2of the motors MG1, MG2. The HVECU70transmits the torque commands Tm1*, Tm2* of the motors MG1, MG2and the target voltage VH* of the high voltage side electric power line54ato the motor ECU40. Control of the inverters41,42and the step-up converter55by the motor ECU40is described above.

Control of the inverters41,42will be described. Each of the inverters41,42in the embodiment executes a first PWM control and a second PWM control in a switched manner (any of the first PWM control and the second PWM control is set as an execution control). The first PWM control switches the transistors T11to T16, T21to T26by generating a first PWM signal of the transistors T11to T16, T21to T26by comparing a voltage command of each of the phases of the motors MG1, MG2with a carrier wave voltage (triangular wave voltage). The second PWM control switches the transistors T11to T16, T21to T26by generating a second PWM signal of the transistors T11to T16, T21to T26based on voltage modulation rates Rm1, Rm2, voltage phases θp1, θp2, and numbers of pulses Np1, Np2in a unit cycle (for example, a half cycle or one cycle of the electrical angles of the motors MG1, MG2). In the second PWM control, the numbers of pulses Np1, Np2are set such that the number of switchings of the transistors T11to T16, T21to T26is smaller than in the first PWM control. The first PWM signal in the first PWM control is generated at an interval Δt1that corresponds to a half cycle or one cycle of the carrier wave voltage (a triangular wave voltage having a frequency of approximately 3 kHz to 5 kHz). The second PWM signal in the second PWM control is generated at an interval Δt2longer than the interval Δt1.

A method of generating the second PWM signal of the transistors T11to T16in the second PWM control of the inverter41will be described. Examples of the method of generating the second PWM signal include a first method, a second method, and a third method below. A method of generating the second PWM signal of the transistors T21to T26in the second PWM control of the inverter42can be considered to be the same.

Examples of the first method include a method of generating the second PWM signal such that a low-order harmonic component is reduced further than in the first PWM control. In the method, the second PWM signal of a pulse waveform (switching pattern) having half wave symmetry [f(ωm1·t)=−f(ωm1·t+π)] and odd symmetry [f(ωm1·t)=f(n−ωm1·t)] is generated, considering the low-order harmonic component. “ωm1” is the rotational angular speed of the motor MG1, and “t” is time. Accordingly, loss in the motor MG1can be reduced along with a reduction in the low-order harmonic component. In the first method, when the motor MG1has a low load (low torque) at low-speed rotation, the effect of reducing loss in the motor MG1by reducing the low-order harmonic component may be small. Furthermore, iron loss in the motor may be increased by an increase in a non-target harmonic component due to a reduction in the low-order harmonic component.

Examples of the second method include a method of generating the second PWM signal such that eddy current loss in the motor MG1is reduced further than in the first PWM control. In the method, the second PWM signal of a pulse waveform (switching pattern) having half wave symmetry [f(ωm1·t)=−f(ωm1·t+π)] is generated, considering not only the low-order harmonic component but also a high-order harmonic component. An advantage of employing such a pulse waveform is that a wider range of selections of pulse waveforms than the pulse waveform used in the first method is available and that an improvement in controllability of both of the amplitude and the phase of a frequency component included in the second PWM signal is expected.

The pulse waveform of the second PWM signal in the second method can be represented as General Formula (1) by using Fourier series. In General Formula (1), “θe1,m” is an m-th switching position of the motor MG1. “a0” is a direct current component, and “n” is 1, 5, 7, 11, 13, . . . (odd integers). “M” is the number of switchings of the transistors T11to T16in the unit cycle of the electrical angle θe1of the motor MG1, and a relationship between the number of switchings M and the number of pulses Np1is “M=Np1−1”. An amplitude Cnand a phase αnof each order can be acquired by General Formula (2) using a coefficient anand a coefficient bnin General Formula (1). In the second method, the second PWM signal is generated by using the amplitude Cn, the phase αn, and the like of each order such that eddy current loss in the motor MG1is reduced. Iron loss Wiin motor MG1can be represented by General Formula (3) as Steinmetz's equation. In General Formula (3), “Wh” is hysteresis loss in the motor MG1, and “We” is eddy current loss in the motor MG1. “Kh” is a hysteresis loss coefficient, and “Bm” is a magnetic flux density. “fm1” is the rotating magnetic flux frequency of the motor MG1, and “Ke” is the eddy current loss coefficient of the motor MG1. Based on General Formula (3), the second method focuses on eddy current loss that has a great proportion in iron loss in the motor MG1. More specifically, the second PWM signal is generated such that eddy current loss as an evaluation function is minimized (eddy current loss in iron loss in the motor MG1is minimized). Accordingly, loss in the motor MG1can be further reduced along with a reduction in each of the harmonic components of the low-order harmonic to the high-order harmonic.

Examples of the third method include a method of generating the second PWM signal such that total loss Lsum1of loss Lmg1in motor MG1and loss Linv1in the inverter41is reduced.FIG. 3is a descriptive diagram illustrating one example of a relationship of the number of pulses Np1with the loss Lmg1in the motor MG1, the loss Linv1in the inverter41, and the total loss Lsum1in the first PWM control and the second PWM control. InFIG. 3, a point A is the number of pulses Np1where the total loss Lsum1in the first PWM control is minimized, and a point B is the number of pulses Np1where the total loss Lsum1in the second PWM control is minimized. The inventors find by experiment and analysis that the number of pulses Np1that leads to a smaller number of switchings of the transistors T11to T16of the inverter41than in the first PWM control may be used as illustrated inFIG. 3in order to reduce the total loss Lsum1further than in the first method and the second method. Accordingly, in the third method, the second PWM signal is generated by using the determined number of pulses Np1such that a reduction in each of the harmonic components of the low-order harmonic to the high-order harmonic and a reduction in the total loss Lsum1are greater than in the first PWM control. Accordingly, the total loss Lsum1can be further reduced along with a reduction in each of the harmonic components of the low-order harmonic to the high-order harmonic.

The embodiment uses the third method of the first method, the second method, and the third method above as the method of generating the second PWM signal of the transistors T11to T16in the second PWM control for the inverter41. The first method and the second method may also be used.

In the case of executing the first PWM control, the number of switchings of the transistors T11to T16, T21to T26is greater with a shorter generation cycle of the PWM signal than in the case of executing the second PWM control. Thus, an increase in noise (electromagnetic noise) due to switching of the transistors T21to T26can be reduced, or controllability of the motors MG1, MG2can be increased. In the case of executing the second PWM control, an increase in electromagnetic noise or a decrease in the controllability of the motors MG1, MG2is more likely than in the case of executing the first PWM control. However, the total loss Lsum1can be further reduced along with a reduction in each of the harmonic components of the low-order harmonic to the high-order harmonic.

When the electricity storage ratio SOC of the battery50at a standstill (during parking) is smaller than or equal to a threshold Slo (for example, 35% or 40%) in the hybrid automobile20of the embodiment, the engine22is cranked and started by the motor MG1by cooperative control of the HVECU70, the engine ECU24, and the motor ECU40. When the engine22is started, the HVECU70sets the target number of rotations Ne* and the target torque Te* of the engine22such that the engine22is operated at a charging operating point of the battery50, sets the torque command Tm1* of the motor MG1such that power is generated by the motor MG1using power from the engine22, and sets the torque command Tm2* of the motor MG2such that torque output from the motor MG1and applied to the drive shaft36through the planetary gear30is canceled out. Next, the HVECU70sets the target voltage VH* of the high voltage side electric power line54abased on the torque commands Tm1*, Tm2* and the numbers of rotations Nm1, Nm2of the motors MG1, MG2. The HVECU70transmits the target number of rotations Ne* and the target torque Te* of the engine22to the engine ECU24and transmits the torque commands Tm1*, Tm2* of the motors MG1, MG2and the target voltage VH* of the high voltage side electric power line54ato the motor ECU40. Control of the engine22by the engine ECU24and control of the inverters41,42and the step-up converter55by the motor ECU40are described above. The battery50is charged from electric power generated by the motor MG1using power from the engine22. When the electricity storage ratio SOC of the battery50reaches a threshold Shi (for example 45% or 50%) that is greater than the threshold Slo, operation of the engine22is stopped, and charging of the battery50is finished.

Next, operation of such configured hybrid automobile20of the embodiment, particularly, operation thereof at the time of setting each of the execution controls of the inverters41,42from the first PWM control or the second PWM control will be described.FIG. 4is a flowchart illustrating one example of an execution control setting routine executed by the motor ECU40. The routine is repeated.

When the execution control setting routine is executed, the motor ECU40, first, receives data such as a permission flag F, a target operating point (the number of rotations Nm1and the torque command Tm1*) P1of the motor MG1, and a target operating point (the number of rotations Nm2and the torque command Tm2*) P2of the motor MG2(step S100). The permission flag F is a flag that is set to a value of one when execution of the second PWM control as controls of the inverters41,42is permitted, and is set to a value of zero when execution of the second PWM control as the controls of the inverters41,42is prevented. The permission flag F input is set by a permission flag setting routine inFIG. 6that is repeated in parallel with the present routine. The numbers of rotations Nm1, Nm2of the motors MG1, MG2input have values that are calculated based on the rotation position θm2of the rotors of the motors MG1, MG2from the rotation position detecting sensors43,44. The torque commands Tm1*, Tm2* of the motors MG1, MG2input have values that are set by the drive control described above.

When the data is input, the value of the received permission flag F is checked (step S110). When the permission flag F has a value of one, that is, when execution of the second PWM control as the controls of the inverters41,42is permitted, a determination as to whether the target operating point P1of the motor MG1falls within the region of the first PWM control or the region of the second PWM control is performed (step S120).FIG. 5is a descriptive diagram illustrating one example of a relationship of the target operating point P1of the motor MG1with the region of the first PWM control and the region of the second PWM control. In the embodiment, the region of the first PWM control and the region of the second PWM control for the target operating point P1of the motor MG1are based on experiment results and analysis results of execution of the first PWM control and the second PWM control for each target operating point P1of the motor MG1, such that a region that is expected to have the effect of execution of the second PWM control to a certain extent is determined as the region of the second PWM control and that a region that is not expected to have the effect is determined as the region of the first PWM control. In the example ofFIG. 5, for the target operating point P1of the motor MG1, areas1to5below are set as the region of the second PWM control, and a region other than the region of the second PWM control is set as the region of the first PWM control. The area1is set to have a region in which the torque command Tm1* is greater than or equal to 10 Nm with the number of rotations Nm1of the motor MG1being 1,000 rpm to 3,500 rpm, and a region in which the torque command Tm1* is −100 Nm to −10 Nm with the number of rotations Nm1being 1,000 rpm to 3,500 rpm. The area2is set to have a region in which the torque command Tm1* is 10 Nm to 150 Nm with the number of rotations Nm1of the motor MG1being 3,500 rpm to 6,000 rpm, and a region in which the torque command Tm1* is −100 Nm to −10 Nm with the number of rotations Nm1being 3,500 rpm to 6,000 rpm. The area3is set to have a region in which the torque command Tm1* is greater than or equal to 150 Nm with the number of rotations Nm1of the motor MG1being 3,500 rpm to 6,000 rpm. The area4is set to have a region in which the torque command Tm1* is 10 Nm to 100 Nm with the number of rotations Nm1of the motor MG1being 6,000 rpm to 9,000 rpm, and a region in which the torque command Tm1* is −50 Nm to −10 Nm with the number of rotations Nm1being 6,000 rpm to 9,000 rpm. The area5is set to have a region in which the torque command Tm1* is 100 Nm to 150 Nm with the number of rotations Nm1of the motor MG1being 6,000 rpm to 9,000 rpm, and a region in which the torque command Tm1* is −100 Nm to −50 Nm with the number of rotations Nm1being 6,000 rpm to 9,000 rpm. InFIG. 5, each of the values of the number of rotations Nm1and the torque command Tm1* of the motor MG1, the divisions of the region of the first PWM control and the region of the second PWM control, and the divisions of the areas (includes the number of areas) in the region of the second PWM control are for illustrative purposes and are appropriately set in accordance with the specifications of the motor MG1, the inverter41, and the like.

When the target operating point P1of the motor MG1falls within the region of the first PWM control in step S120, the first PWM control is set as the execution control of the inverter41(step S130). Meanwhile, when the target operating point P1of the motor MG1falls within the region of the second PWM control, the second PWM control is set as the execution control of the inverter41(step S140).

Next, a determination as to whether the target operating point P2of the motor MG2falls within the region of the first PWM control or the region of the second PWM control is performed (step S150). The region of the first PWM control and the region of the second PWM control for the target operating point P2of the motor MG2are set to be the same as the region of the first PWM control and the region of the second PWM control for the target operating point P1of the motor MG1. When the target operating point P2of the motor MG2falls within the region of the first PWM control, the first PWM control is set as the execution control of the inverter42(step S160), and the present routine is finished. Meanwhile, when the target operating point P2of the motor MG2falls within the region of the second PWM control, the second PWM control is set as the execution control of the inverter42(step S170), and the present routine is finished.

When the permission flag F has a value of zero in step S110, that is, when execution of the second PWM control as the controls of the inverters41,42is prevented, the first PWM control is set as the execution controls of the inverters41,42regardless of the target operating points P1, P2of the motors MG1, MG2(step S180), and the present routine is finished.

Next, the permission flag setting routine inFIG. 6will be described. The routine is repeated by the motor ECU40in parallel with the execution control setting routine inFIG. 4. When the permission flag setting routine is executed, the motor ECU40receives the vehicle speed V from the vehicle speed sensor88through the HVECU70(step S200) and determines whether or not the input vehicle speed V is lower than or equal to a threshold Vref (step S210). The process of step S210is a process of determining whether or not quietness is needed inside the vehicle. The threshold Vref can be, for example, 20 km/h, 25 km/h, or 30 km/h. When the vehicle speed V is low, road noise is smaller than when the vehicle speed V is high, and noise (electromagnetic noise) due to switching of the transistors T11to T16, T21to T26of the inverters41,42is unlikely to be mixed with road noise. Thus, a driver or the like is considered likely to perceive electromagnetic noise. Based on this fact, the embodiment determines whether or not the vehicle speed V is lower than or equal to the threshold Vref, thereby determining whether or not quietness is needed inside the vehicle.

When the vehicle speed V is higher than the threshold Vref in step S210, the motor ECU40determines that quietness is not needed inside the vehicle (the driver or the like is unlikely to perceive electromagnetic noise), sets the permission flag F to a value of one, that is, permits execution of the second PWM control as the controls of the inverters41,42(step S220), and finishes the present routine. In this case, the first PWM control or the second PWM control is set as each of the execution controls of the inverters41,42in accordance with the target operating points P1, P2of the motors MG1, MG2in the execution control setting routine inFIG. 4.

Meanwhile, when the vehicle speed V is lower than or equal to the threshold Vref, the motor ECU40determines that quietness is needed inside the vehicle (the driver or the like is likely to perceive electromagnetic noise), sets the permission flag F to a value of zero, that is, prevents execution of the second PWM control as the controls of the inverters41,42(step S230), and finishes the present routine. In this case, the first PWM control is set as both of the execution controls of the inverters41,42regardless of the target operating points P1, P2of the motors MG1, MG2in the execution control setting routine inFIG. 4.

As described above, when the second PWM control is executed as the controls of the inverters41,42, electromagnetic noise is likely to be greater than when the first PWM control is executed. Thus, when the second PWM control is executed as the controls of the inverters41,42at the time of the vehicle speed V being comparatively low, the driver or the like may perceive electromagnetic noise. When the vehicle speed V is lower than or equal to the threshold Vref, the embodiment determines that quietness is needed inside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control), thereby being capable of more sufficiently satisfying a need for quietness inside the vehicle than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

When the vehicle speed V is lower than or equal to the threshold Vref, the hybrid automobile20of the embodiment described heretofore determines that quietness is needed inside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control). Accordingly, a need for quietness inside the vehicle can be more sufficiently satisfied than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

In the hybrid automobile20of the embodiment, while the motor ECU40sets the permission flag F by the permission flag setting routine inFIG. 6, the motor ECU40may set the permission flag F by any of permission flag setting routines inFIG. 7toFIG. 10. Hereinafter, the permission flag setting routines will be described in order.

First, the permission flag setting routine inFIG. 7will be described. When the permission flag setting routine inFIG. 7is executed, the motor ECU40receives a travel mode (the HV travel mode or the EV travel mode) (step S300) and determines whether or not the input travel mode is the EV travel mode (step S310). The process of step S310is a process of determining whether or not quietness is needed inside the vehicle, as in the process of step S210. In the EV travel mode, operation of the engine22is stopped (engine sound is not generated). Thus, the driver or the like is considered more likely to perceive electromagnetic noise than in the HV travel mode. Based on this fact, the modification example determines whether or not the travel mode is the EV travel mode, thereby determining whether or not quietness is needed inside the vehicle.

When the travel mode is not the EV travel mode (is the HV travel mode) in step S310, the motor ECU40determines that quietness is not needed inside the vehicle (the driver or the like is unlikely to perceive electromagnetic noise), sets the permission flag F to a value of one, that is, permits execution of the second PWM control as the controls of the inverters41,42(step S320), and finishes the present routine. Meanwhile, when the travel mode is the EV travel mode, the motor ECU40determines that quietness is needed inside the vehicle (the driver or the like is likely to perceive electromagnetic noise), sets the permission flag F to a value of zero, that is, prevents execution of the second PWM control as the controls of the inverters41,42(step S330), and finishes the present routine.

As described above, when the second PWM control is executed as the controls of the inverters41,42, electromagnetic noise is likely to be greater than when the first PWM control is executed. Thus, when the second PWM control is executed as the controls of the inverters41,42at the time of the travel mode being the EV travel mode, the driver or the like may perceive electromagnetic noise. When the travel mode is the EV travel mode, the modification example determines that quietness is needed inside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control), thereby being capable of more sufficiently satisfying a need for quietness inside the vehicle than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

Next, the permission flag setting routine inFIG. 8will be described. When the permission flag setting routine inFIG. 8is executed, the motor ECU40receives the number of lanes nl in the current location of the automobile from the navigation device90through the HVECU70(step S400) and determines whether or not the input number of lanes nl is smaller than or equal to a threshold nlref (step S410). The process of step S410is a process of determining whether or not quietness is needed outside the vehicle. The threshold nlref can be, for example, a value that corresponds to one lane on one side. When the number of lanes is small, the width of the road is smaller than when the number of lanes is great, and a pedestrian or the like around the automobile is considered more likely to perceive electromagnetic noise. Based on this fact, the modification example determines whether or not the number of lanes nl is smaller than or equal to the threshold nlref, thereby determining whether or not quietness is needed outside the vehicle.

When the number of lanes nl is greater than the threshold nlref in step S410, the motor ECU40determines that quietness is not needed outside the vehicle (the pedestrian or the like around the automobile is unlikely to perceive electromagnetic noise), sets the permission flag F to a value of one, that is, permits execution of the second PWM control as the controls of the inverters41,42(step S420), and finishes the present routine. Meanwhile, when the number of lanes nl is smaller than or equal to the threshold nlref, the motor ECU40determines that quietness is needed outside the vehicle (the pedestrian or the like around the automobile is likely to perceive electromagnetic noise), sets the permission flag F to a value of zero, that is, prevents execution of the second PWM control as the controls of the inverters41,42(step S430), and finishes the present routine.

As described above, when the second PWM control is executed as the controls of the inverters41,42, electromagnetic noise is likely to be greater than when the first PWM control is executed. Thus, when the second PWM control is executed as the controls of the inverters41,42at the time of the number of lanes nl being small, the pedestrian or the like around the automobile may perceive electromagnetic noise. When the number of lanes nl is smaller than or equal to the threshold nlref, the modification example determines that quietness is needed outside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control), thereby being capable of more sufficiently satisfying a need for quietness outside the vehicle than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the pedestrian or the like around the automobile can have more sufficiently reduced perception of electromagnetic noise.

In the permission flag setting routine inFIG. 8, while the permission flag F is set based on the number of lanes nl in the current location of the automobile, the permission flag F may be set based on the width, the area (an urban area or a suburb), the legal speed, or the like in the current location of the automobile instead of or in addition to the number of lanes nl. For example, when all conditions including a condition that the number of lanes nl is smaller than or equal to the threshold nlref, a condition that the width is smaller than or equal to a predetermined width, a condition that the area is an urban area, and a condition that the legal speed is lower than or equal to a predetermined speed are not established, the motor ECU40may determine that quietness is not needed outside the vehicle, and set the permission flag F to a value of one (prevent execution of the second PWM control as the controls of the inverters41,42). When at least one condition is established, the motor ECU40may determine that quietness is needed outside the vehicle, and set the permission flag F to a value of zero (permit execution of the second PWM control as the controls of the inverters41,42).

Next, the permission flag setting routine inFIG. 9will be described. When the permission flag setting routine inFIG. 9is executed, the motor ECU40receives a current time tnow from a timepiece, not illustrated, through the HVECU70(step S500) and uses the input current time tnow to determine whether or not it is at night (step S510). “Night” may be uniformly determined as a time range of a first time (for example, 9 p.m., 10 p.m., or 11 p.m.) to a second time (5 a.m., 6 a.m., or 7 a.m. the next day) or may be determined as a time range of sunset to sunrise or the like in accordance with the season or the date. The process of step S510is a process of determining whether or not quietness is needed outside the vehicle, as in the process of step S410. Generally, at night, the pedestrian or the like around the automobile is more likely to perceive electromagnetic noise than at other than night (at day). In addition, a permissible noise level at night is mostly set to be lower than the permissible noise level at other than night (at day). Based on these facts, the modification example determines whether or not it is at night, thereby determining whether or not quietness is needed outside the vehicle.

When it is not at night (it is at day) in step S510, the motor ECU40determines that quietness is not needed outside the vehicle (the pedestrian or the like around the automobile is unlikely to perceive electromagnetic noise), sets the permission flag F to a value of one, that is, permits execution of the second PWM control as the controls of the inverters41,42(step S520), and finishes the present routine. Meanwhile, when it is nighttime, the motor ECU40determines that quietness is needed outside the vehicle (the pedestrian or the like around the automobile is likely to perceive electromagnetic noise), sets the permission flag F to a value of zero, that is, prevents execution of the second PWM control as the controls of the inverters41,42(step S530), and finishes the present routine.

As described above, when the second PWM control is executed as the controls of the inverters41,42, electromagnetic noise is likely to be greater than when the first PWM control is executed. Thus, when the second PWM control is executed as the controls of the inverters41,42at night, the pedestrian or the like around the automobile may perceive electromagnetic noise. At night, the modification example determines that quietness is needed outside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control), thereby being capable of more sufficiently satisfying a need for quietness outside the vehicle than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the pedestrian or the like around the automobile can have more sufficiently reduced perception of electromagnetic noise.

Next, the permission flag setting routine inFIG. 10will be described. When the permission flag setting routine inFIG. 10is executed, the motor ECU40receives the vehicle speed V from the vehicle speed sensor88through the HVECU70(step S600) and uses the input vehicle speed V to determine whether or not the hybrid automobile20is at a standstill (step S610). The process of step S610is a process of determining whether or not quietness is needed inside the vehicle, as in the process of step S210. Since road noise is not generated at a standstill, the driver or the like at a standstill is considered more likely to perceive electromagnetic noise than during traveling. Based on this fact, the modification example determines whether or not the hybrid automobile20is at a standstill, thereby determining whether or not quietness is needed inside the vehicle.

When the hybrid automobile20is not at a standstill in step S610, the motor ECU40determines that quietness is not needed inside the vehicle (the driver or the like is unlikely to perceive electromagnetic noise), sets the permission flag F to a value of one, that is, permits execution of the second PWM control as the controls of the inverters41,42(step S620), and finishes the present routine. Meanwhile, when the hybrid automobile20is at a standstill, the motor ECU40determines that quietness is needed inside the vehicle (the driver or the like is likely to perceive electromagnetic noise), sets the permission flag F to a value of zero, that is, prevents execution of the second PWM control as the controls of the inverters41,42(step S630), and finishes the present routine.

As described above, when the second PWM control is executed as the controls of the inverters41,42, electromagnetic noise is likely to be greater than when the first PWM control is executed. Thus, when the second PWM control is executed as the controls of the inverters41,42at a standstill, the driver or the like may perceive electromagnetic noise. When the hybrid automobile20is at a standstill, the modification example determines that quietness is needed inside the vehicle, and executes the first PWM control as both of the controls of the inverters41,42(by preventing execution of the second PWM control), thereby being capable of more sufficiently satisfying a need for quietness inside the vehicle than in the execution of the second PWM control as at least one of the controls of the inverters41,42. Specifically, the driver or the like can have more sufficiently reduced perception of electromagnetic noise.

As described in the routines inFIG. 6toFIG. 10, the hybrid automobile20of the embodiment and the modification examples uses the following conditions as conditions for setting the permission flag F to a value of zero (preventing execution of the second PWM control as the controls of the inverters41,42). The routine inFIG. 6uses a condition (A) the vehicle speed V is lower than or equal to the threshold Vref. The routine inFIG. 7uses a condition (B) the travel mode is the EV travel mode. The routine inFIG. 8uses a condition (C) the number of lanes nl is smaller than or equal to the threshold nlref. The routine inFIG. 9uses a condition (D) it is at night. The routine inFIG. 10uses a condition (E) the hybrid automobile20is at a standstill. Some or all of (A) to (E) may also be used in combination. For example, when all of (A) to (E) are used in combination, the permission flag F may be set to a value of zero at the time of establishment of at least one of (A) to (E).

While the hybrid automobile20of the embodiment prevents execution of the second PWM control (executes the first PWM control) as both of the controls of the inverters41,42regardless of the target operating points P1, P2of the motors MG1, MG2when quietness is needed, the hybrid automobile20may restrict execution of the second PWM control. For example, execution of the second PWM control as the controls of the inverters41,42may be prevented outside the area1(refer toFIG. 5) of the region of the second PWM control, or execution of the second PWM control may be prevented at other times than cruise travel in the region of the second PWM control.

While the hybrid automobile20of the embodiment includes the engine ECU24, the motor ECU40, the battery ECU52, and the HVECU70, some or all thereof may be configured as a single electronic control unit.

While the step-up converter55is disposed between the battery50and the inverters41,42in the hybrid automobile20of the embodiment, the step-up converter55may not be disposed.

While the hybrid automobile20of the embodiment uses the battery50as an electricity storing device, the hybrid automobile20may use a capacitor.

The hybrid automobile20of the embodiment is configured such that the engine22and the motor MG1are connected through the planetary gear30to the drive shaft36connected to the drive wheels39a,39band that the motor MG2is connected to the drive shaft36. However, as illustrated in a hybrid automobile120of a modification example inFIG. 11, a motor MG may be connected through a transmission130to the drive shaft36connected to the drive wheels39a,39b, and the engine22may be connected to a rotating shaft of the motor MG through a clutch129. In addition, as illustrated in a hybrid automobile220of a modification example inFIG. 12, a so-called series hybrid automobile such that the motor MG2for traveling is connected to the drive shaft36connected to the drive wheels39a,39band that the motor MG1for power generation is connected to an output shaft of the engine22may be used. Furthermore, as illustrated in an electric automobile320of a modification example inFIG. 13, an electric automobile in which the motor MG for traveling is connected to the drive shaft36connected to the drive wheels39a,39bmay be used. When the electric automobile320is used, the motor ECU40can execute the permission flag setting routines inFIG. 6andFIG. 8toFIG. 10of the permission flag setting routines inFIG. 6toFIG. 10.

The embodiment of the present disclosure is not limited to such forms of automobiles and may be embodied as a drive apparatus mounted in a moving object such as an automobile or as a drive apparatus incorporated in a facility that is not a moving object, such as a construction facility.

Correspondence between main elements of the embodiments and main elements of the present disclosure disclosed in “SUMMARY” will be described. In the embodiment, the motor MG2corresponds to a “motor”, and the inverter42corresponds to an “inverter”. The battery50corresponds to an “electricity storing device”, and the motor ECU40corresponds to an “electronic control unit”.

The correspondence between the main elements of the embodiment and the main elements of the present disclosure disclosed in “SUMMARY” is one example for specific description of the embodiment for embodying the present disclosure disclosed in “SUMMARY”, and thus, does not limit the elements of the present disclosure disclosed in “SUMMARY”. That is, the present disclosure disclosed in “SUMMARY” is to be interpreted based on the disclosure in “SUMMARY”, and the embodiment is merely one specific example of the present disclosure disclosed in “SUMMARY”.

While the present disclosure is described by using the embodiment, the present disclosure is not limited to such an embodiment and may be embodied in various forms to an extent not departing from the gist of the present disclosure.

The present disclosure can be used in, for example, a manufacturing industry of drive apparatuses and automobiles.