Vehicle-mounted motor driving control board

An object of the present invention is to achieve reductions in size and costs of a vehicle-mounted motor driving control board in a configuration which allows the redundancy of a power supply to be ensured. The vehicle-mounted motor driving control board is formed by one printed circuit board on which are formed two inverter driving circuits for driving two inverter circuits for three-phase motors, and a voltage step-up/step-down driving circuit for driving a voltage step-up/step-down circuit for supplying electric power to the inverter circuits. The vehicle-mounted motor driving control board further includes a first power supply circuit for supplying electric power to part of constituent circuits constituting the voltage step-up/step-down driving circuit and the two inverter driving circuits, and a second power supply circuit for supplying electric power to the remainder of the constituent circuits in the voltage step-up/step-down driving circuit and the two inverter driving circuits.

TECHNICAL FIELD

The present invention relates to a vehicle-mounted motor driving control board on which is formed a circuit for driving two inverter circuits connected respectively to two three-phase motors mounted on a vehicle and a voltage step-up/step-down circuit for supplying electric power to the inverter circuits.

BACKGROUND ART

As presented in Patent Document 1, two three-phase motors, two inverter circuits connected respectively to the three-phase motors, and a voltage step-up/step-down circuit for supplying electric power to the inverter circuits are mounted in a conventional hybrid automobile. The voltage step-up/step-down circuit is formed by a chopper circuit, and performs a voltage step-up conversion and a voltage step-down conversion on an input voltage supplied from a high-voltage battery to thereby generate a P-phase potential and an N-phase potential which are necessary for the inverter circuits. For example, one of the two three-phase motors is a motor for driving wheels, and the other is a motor for electric power regeneration.

A control board on which is formed a circuit for driving the two inverter circuits and the voltage step-up/step-down circuit is further mounted in the conventional hybrid automobile. The control board is referred to hereinafter as a vehicle-mounted motor driving control board. This vehicle-mounted motor driving control board is comprised of a single printed circuit board, and is connected to a semiconductor module including two inverter circuits and a voltage step-up/step-down circuit.

The vehicle-mounted motor driving control board includes two inverter circuit driving circuits which are circuits for driving the two inverter circuits, respectively, and a voltage step-up/step-down driving circuit which is a circuit for driving the voltage step-up/step-down circuit.

The vehicle-mounted motor driving control board further includes a power supply circuit for supplying a constant DC voltage to the two inverter circuit driving circuits and to the voltage step-up/step-down driving circuit. This power supply circuit converts an input voltage supplied from a battery into a control voltage (output voltage) necessary for the two inverter circuit driving circuits and the voltage step-up/step-down driving circuit.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF INVENTION

Problems to be Solved by the Invention

In general, a conventional vehicle-mounted motor driving control board includes three power supply circuits corresponding respectively to two inverter circuit driving circuits and a voltage step-up/step-down driving circuit. If a failure of one of the power supply circuits occurs, the vehicle-mounted motor driving control board, which includes the three power supply circuits, is able to continue part of the operations of the two inverter circuits, thereby ensuring the redundancy of the power supply.

However, further reductions in size and costs of the vehicle-mounted motor driving control board have recently been required. In addition, it is important for the vehicle-mounted motor driving control board to ensure the redundancy of the power supply.

It is an object of the present invention to achieve reductions in size and costs of a vehicle-mounted motor driving control board in a configuration which allows the redundancy of a power supply to be ensured.

Means to Solve the Problem

A vehicle-mounted motor driving control board according to one aspect of the present invention is formed by one printed circuit board and includes a circuit formed thereon which drives two inverter circuits connected respectively to two three-phase motors mounted on a vehicle and a voltage step-up/step-down circuit for supplying electric power to the inverter circuits. Further, the vehicle-mounted motor driving control board according to the one aspect of the present invention includes: a voltage step-up/step-down driving circuit, a first inverter driving circuit, a second inverter driving circuit, a first power supply circuit, and a second power supply circuit which will be described below. The aforementioned voltage step-up/step-down driving circuit is a circuit for driving the aforementioned voltage step-up/step-down circuit. The aforementioned first inverter driving circuit is a circuit for driving one of the aforementioned two inverter circuits. The aforementioned second inverter driving circuit is a circuit for driving the other of the aforementioned two inverter circuits. The aforementioned first power supply circuit is a circuit for supplying electric power to part of constituent circuits constituting the aforementioned voltage step-up/step-down driving circuit, the aforementioned first inverter driving circuit and the aforementioned second inverter driving circuit. The aforementioned second power supply circuit is a circuit for supplying electric power to the remainder of the aforementioned constituent circuits constituting the aforementioned voltage step-up/step-down driving circuit, the aforementioned first inverter driving circuit and the aforementioned second inverter driving circuit.

Effects of the Invention

The vehicle-mounted motor driving control board according to the one aspect of the present invention described above achieves the reductions in size and cost in corresponding relation to the omission of one power supply circuit, as compared with a conventional board including three power supply circuits. Further, in the vehicle-mounted motor driving control board, the two power supply circuits share the supply of electric power (DC voltages) to the plurality of constituent circuits constituting the voltage step-up/step-down driving circuit and the two inverter driving circuits. Thus, if a failure of one of the power supply circuits occurs, the vehicle-mounted motor driving control board is capable of implementing the function of continuing the operation of part of the two inverter circuits (the redundancy of the power supply).

DESCRIPTION OF EMBODIMENTS

Description will now be given on embodiments of the present invention with reference to the accompanying drawings. The embodiments to be described below are examples embodying the present invention, and are not cases which limit the technical scope of the present invention.

A vehicle-mounted motor driving control board according to each embodiment to be described below is mounted in an electric vehicle such as a hybrid automobile.

First Embodiment

Schematic Configuration of Vehicle-Mounted Motor Driving Device

With reference toFIGS. 1 and 2, the schematic configuration of a vehicle-mounted motor driving control board10and a vehicle-mounted motor driving device including the vehicle-mounted motor driving control board10according to a first embodiment of the present invention will be described. Two three-phase motors9aand9b, two inverter circuits8aand8bconnected respectively to the two three-phase motors9aand9b, and a voltage step-up/step-down circuit7for supplying electric power to the two inverter circuits8aand8bare also mounted in a vehicle in which the vehicle-mounted motor driving control board10is mounted.

In the present embodiment, a first three-phase motor9awhich is one of the two three-phase motors9aand9bis a motor for driving wheels. A second three-phase motor9bwhich is the other of the two three-phase motors9aand9bis a motor for electric power regeneration which regenerates electric power by means of a rotatably driving force transmitted from wheels. Thus, the second three-phase motor9baccording to the present embodiment is also a three-phase AC generator.

The two inverter circuits8aand8binclude a first inverter circuit8aconnected to the first three-phase motor9a, and a second inverter circuit8bconnected to the second three-phase motor9b.

FIG. 2is a schematic diagram of the voltage step-up/step-down circuit7, the first inverter circuit8aand the second inverter circuit8bwhich are circuits to be driven by the vehicle-mounted motor driving control board10. InFIG. 2, the reference character CP designates a chopper circuit; P and N designate a P phase and an N phase, respectively, of an output from the voltage step-up/step-down circuit7; M designates a motor; G designates electric power regeneration (electricity production); and U, V and W designate a U phase, a V phase and a W phase, respectively, of a three-phase alternating current.

The voltage step-up/step-down circuit7is formed by chopper circuits, and performs a voltage step-up conversion and a voltage step-down conversion on an input voltage supplied from a high-voltage battery70to thereby generate a P-phase potential and an N-phase potential which are necessary for the first inverter circuit8aand the second inverter circuit8b. To this end, the voltage step-up/step-down circuit7includes an N-phase power switching circuit71which steps down the input voltage to generate the N-phase potential, and a P-phase power switching circuit72which steps up the input voltage to generate the P-phase potential. An output voltage from the high-voltage battery70is, for example, not less than 100 V.

Each of the N-phase power switching circuit71and the P-phase power switching circuit72includes an IGBT (Insulated gate bipolar transistor), and a FWD (Free Wheeling Diode) connected in inverse-parallel with the IGBT. The N-phase power switching circuit71and the P-phase power switching circuit72are connected in series with each other to form a half-bridge. The FWD is a diode for commutating a load current.

A connection point of the N-phase power switching circuit71and the P-phase power switching circuit72is connected through a choke coil63to a positive electrode end of the high-voltage battery70. A first capacitor61for storing high-voltage electricity therein is connected in parallel with the high-voltage battery70with respect to a voltage supply line from the high-voltage battery70to the voltage step-up/step-down circuit7.

A low-potential terminal of the N-phase power switching circuit71is a N-phase output end of the voltage step-up/step-down circuit7, and is connected to a low-potential DC power supply line of the first inverter circuit8aand the second inverter circuit8b. On the other hand, a high-potential terminal of the P-phase power switching circuit72is a P-phase output end of the voltage step-up/step-down circuit7, and is connected to a high-potential DC power supply line of the first inverter circuit8aand the second inverter circuit8b.

The voltage step-up/step-down circuit7outputs a DC voltage stepped up intermittently at a predetermined frequency in accordance with a driving signal from a voltage step-up/step-down driving circuit2. It should be noted that the configuration and operation of the voltage step-up/step-down circuit7formed by chopper circuits are well known.

The first inverter circuit8aincludes power switching circuits811to813for the respective three phases on the N-phase side (lower arm side), and power switching circuits814to816for the respective three phases on the P-phase side (upper arm side). The U-phase power switching circuit811on the N-phase side and the U-phase power switching circuit814on the P-phase side constitute a circuit identical with the voltage step-up/step-down circuit7. The V-phase power switching circuit812on the N-phase side and the V-phase power switching circuit815on the P-phase side also constitute a circuit identical with the voltage step-up/step-down circuit7. Further, the W-phase power switching circuit813on the N-phase side and the W-phase power switching circuit816on the P-phase side also constitute a circuit identical with the voltage step-up/step-down circuit7.

The first inverter circuit8aoutputs three-phase AC voltages (U-phase voltage, V-phase voltage and W-phase voltage) which are out of phase with each other by 120 degrees in accordance with a driving signal from a first inverter driving circuit1a.

On the other hand, the second inverter circuit8bforms a circuit identical with the first inverter circuit8a. Specifically, the second inverter circuit8bincludes a U-phase power switching circuit821on the N-phase side, a U-phase power switching circuit824on the P-phase side, a V-phase power switching circuit822on the N-phase side, a V-phase power switching circuit825on the P-phase side, a W-phase power switching circuit823on the N-phase side, and a W-phase power switching circuit826on the P-phase side.

The second inverter circuit8b, however, converts three-phase AC voltages supplied from the second three-phase motor9binto a DC voltage in accordance with a driving signal from a second inverter driving circuit1bto store the DC voltage in a second capacitor62. The second capacitor62is connected in parallel with the second inverter circuit8bwith respect to a voltage supply line from the voltage step-up/step-down circuit7. It should be noted that the configuration and operation of the first inverter circuit8aand the second inverter circuit8bwhich are three-phase inverter circuits are well known.

Configuration of Vehicle-Mounted Motor Driving Control Board

Next, the configuration of the vehicle-mounted motor driving control board10will be described with reference toFIG. 1andFIGS. 3 and 4.

The vehicle-mounted motor driving control board10is formed by a single printed circuit board, and is a board on which circuits for driving the first inverter circuit8a, the second inverter circuit8band the voltage step-up/step-down circuit7are formed.

As shown inFIG. 1, the vehicle-mounted motor driving control board10includes the voltage step-up/step-down driving circuit2, the first inverter driving circuit1a, the second inverter driving circuit1b, a first power supply circuit3a, and a second power supply circuit3b.

Voltage Step-Up/Step-Down Driving Circuit

The voltage step-up/step-down driving circuit2is a circuit for driving the voltage step-up/step-down circuit7. As shown inFIG. 4, the voltage step-up/step-down driving circuit2includes an N-phase voltage step-up/step-down driving circuit201for outputting a driving signal to the N-phase power switching circuit71of the voltage step-up/step-down circuit7, and a P-phase voltage step-up/step-down driving circuit202for outputting a driving signal to the P-phase power switching circuit72of the voltage step-up/step-down circuit7.

The N-phase voltage step-up/step-down driving circuit201outputs a gate voltage (driving signal) to between the gate and emitter of the IGBT of the N-phase power switching circuit71. Likewise, the P-phase voltage step-up/step-down driving circuit202outputs a gate voltage (driving signal) to between the gate and emitter of the IGBT of the P-phase power switching circuit72. The N-phase voltage step-up/step-down driving circuit201and the P-phase voltage step-up/step-down driving circuit202are examples of constituent circuits200of the voltage step-up/step-down driving circuit2.

Inverter Driving Circuits

The first inverter driving circuit1ais a circuit for driving the first inverter circuit8a. As shown inFIG. 4, the first inverter driving circuit1aincludes a first N-phase inverter driving circuit111, and a first P-phase inverter driving circuit112. The first N-phase inverter driving circuit111is a circuit for outputting a driving signal to the power switching circuits811to813for the respective three phases on the N-phase side (lower arm side) in the first inverter circuit8a. The first P-phase inverter driving circuit112, on the other hand, is a circuit for outputting a driving signal to the power switching circuits814to816for the respective three phases on the P-phase side (upper arm side) in the first inverter circuit8a. The first N-phase inverter driving circuit111and the first P-phase inverter driving circuit112are examples of constituent circuits110of the first inverter driving circuit1a.

The second inverter driving circuit1b, on the other hand, is a circuit for driving the second inverter circuit8b. As shown inFIG. 4, like the first inverter driving circuit1a, the second inverter driving circuit1bincludes a second N-phase inverter driving circuit121, and a second P-phase inverter driving circuit122. The second N-phase inverter driving circuit121is a circuit for outputting a driving signal to the power switching circuits821to823for the respective three phases on the N-phase side in the second inverter circuit8b. The second P-phase inverter driving circuit122, on the other hand, is a circuit for outputting a driving signal to the power switching circuits824to826for the respective three phases on the P-phase side in the second inverter circuit8b. The driving signals are gate voltage signals of the IGBTs provided in the two inverter circuits8aand8b. The second N-phase inverter driving circuit121and the second P-phase inverter driving circuit122are examples of constituent circuits120of the second inverter driving circuit1b.

Power Supply Circuits

The first power supply circuit3ais a circuit for supplying DC power to some of the plurality of constituent circuits200,110and120constituting the voltage step-up/step-down driving circuit2, the first inverter driving circuit1aand the second inverter driving circuit1b. Likewise, the second power supply circuit3bis a circuit for supplying electric power to the remainder of the plurality of constituent circuits200,110and120constituting the voltage step-up/step-down driving circuit2, the first inverter driving circuit1aand the second inverter driving circuit1b.

That is, the first power supply circuit3aand the second power supply circuit3bshare the supply of DC control voltages to the plurality of constituent circuits200,110and120constituting the voltage step-up/step-down driving circuit2and the two inverter driving circuits1aand1b.

FIG. 3is a schematic diagram of a DC-DC converter3which is an example of the first power supply circuit3aand the second power supply circuit3b. The DC-DC converter3includes a power transformer31, an inverter circuit32, rectifier circuits33, and an output voltage stabilizing circuit34.

The power transformer31includes one primary coil310and a plurality of secondary coils311to316. In the following description, the four outer edge portions of the power transformer31are as follows. An outer edge portion of the power transformer31where the primary coil310is disposed is referred to as a first outer edge portion F1; an outer edge portion thereof adjacent to the first outer edge portion F1is referred to as a second outer edge portion F2; an outer edge portion thereof on the opposite side from the first outer edge portion F1is referred to as a third outer edge portion F3; and an outer edge portion thereof on the opposite side from the second outer edge portion F2is referred to as a fourth outer edge portion F4.

More specifically, the power transformer31includes the primary coil310and the secondary coils316and315which are arranged along the first outer edge portion F1, and the secondary coils311to314which are arranged along the third outer edge portion F3.

In the example shown inFIG. 3, the power transformer31includes the primary coil310, a sixth secondary coil316and a fifth secondary coil315which are arranged in order from the second outer edge portion F2side along the first outer edge portion F1. The power transformer31shown inFIG. 3further includes a first secondary coil311, a second secondary coil312, a third secondary coil313and a fourth secondary coil314which are arranged in order from the second outer edge portion F2side along the third outer edge portion F3. That is, the power transformer31in the example shown inFIG. 3includes the one primary coil310and the six secondary coils311to316.

Of the six secondary coils311to316, the sixth secondary coil316disposed adjacent to the primary coil310is connected through one of the rectifier circuits33to the output voltage stabilizing circuit34. Each of the remaining five secondary coils, i.e. the first secondary coil311to the fifth secondary coil315, is connected through one of the rectifier circuits33to any one of the plurality of constituent circuits200,110and120constituting the voltage step-up/step-down driving circuit2, the first inverter driving circuit1aand the second inverter driving circuit1bwhich are formed on the vehicle-mounted motor driving control board10.

The inverter circuit32converts a DC input voltage inputted from a low-voltage battery30into an AC voltage to supply the AC voltage to the primary coil310. It should be noted that the low-voltage battery30is a battery for outputting a relatively low voltage of 12 V or 24 V, for example.

The rectifier circuits33are connected to the plurality of secondary coils311to316, and convert an AC voltage generated in each of the secondary coils311to316into a DC voltage. Accordingly, the DC-DC converter3shown inFIG. 3includes the six rectifier circuits33. Output ends of the five rectifier circuits33connected respectively to the five secondary coils, i.e. the first secondary coil311to the fifth secondary coil315, are ends for outputting the control voltage.

The use of the DC-DC converter3shown inFIG. 3as the first power supply circuit3aand the second power supply circuit3bachieves the power supply circuits capable of supplying electric power with stability.

By enhancing the insulating properties of the secondary coils connected to the constituent circuits200of the voltage step-up/step-down driving circuit2among the secondary coils of the DC-DC converter3, the reliability of the power supply circuits is improved.

The output voltage stabilizing circuit34performs feedback control on the inverter circuit32in accordance with a difference between an output voltage and a target voltage of the sixth secondary coil316to cause the output voltages from the respective secondary coils311to316to be fixed at the target voltage. The feedback control is, for example, PWM (Pulse Width Modulation) control of the control signal to be outputted to a MOS transistor not shown provided in the inverter circuit32.

FIG. 4is a diagram showing a supply system for the control voltages in the vehicle-mounted motor driving control board10. When the DC-DC converter3shown inFIG. 3is employed as the first power supply circuit3aand the second power supply circuit3b, it is contemplated that the first power supply circuit3aand the second power supply circuit3bsupply the control voltages to the voltage step-up/step-down driving circuit2, the first inverter driving circuit1aand the second inverter driving circuit1bin accordance with the system shown inFIG. 4.

In the example shown inFIG. 4, the first power supply circuit3asupplies electric power (control voltage) to the N-phase voltage step-up/step-down driving circuit201which is part of the voltage step-up/step-down driving circuit2and to the first N-phase inverter driving circuit111and the first P-phase inverter driving circuit112which are all constituent circuits110constituting the first inverter driving circuit. The second power supply circuit3bsupplies electric power (control voltage) to the remaining circuits, i.e. to the P-phase voltage step-up/step-down driving circuit202which is part of the voltage step-up/step-down driving circuit2and to the second N-phase inverter driving circuit121and the second P-phase inverter driving circuit122which are all constituent circuits120constituting the second inverter driving circuit1b.

From the viewpoint of the fact that the decrease in the number of types of components achieves the further reduction in costs, it is desirable that the first power supply circuit3aand the second power supply circuit3bare circuits identical in specs with each other. The circuits identical in specs with each other mean that the circuits are identical in components constituting the circuits and in structure for connecting the components with each other.

Redundancy of Power Supply

When the first power supply circuit3aand the second power supply circuit3bsupply the control voltages in accordance with the system shown inFIG. 4, the operation of part of the two inverter circuits8aand8bcan be continued to ensure the redundancy of the power supply if a failure of one of the first power supply circuit3aand the second power supply circuit3boccurs.

FIG. 5is a diagram schematically showing an operating state of circuits to be driven when a failure of the first power supply circuit3aoccurs. InFIG. 5, circuits marked with crosses are circuits the operation of which is stopped by the failure of the first power supply circuit3a.

When the failure of the first power supply circuit3aoccurs, the N-phase voltage step-up/step-down driving circuit201of the voltage step-up/step-down driving circuit2and the first inverter driving circuit1aare in an operation-stopped state. Thus, the operation of the IGBTs is stopped in the N-phase power switching circuit71of the voltage step-up/step-down circuit7and in the entire first inverter circuit8a.

On the other hand, the P-phase voltage step-up/step-down driving circuit202of the voltage step-up/step-down circuit2and the second inverter circuit8bfor electric power regeneration operate normally, and the FWD on the N-phase side in the voltage step-up/step-down driving circuit7operates normally. Thus, these circuits operating normally and the choke coil63(inductance) constitute a voltage step-down chopper circuit which in turn steps down the voltage of the second capacitor62and charges the first capacitor61.

As described above, when the failure of the first power supply circuit3aoccurs but the second power supply circuit3bis normal, the second inverter circuit8bfor electric power regeneration is able to continue the operation of storing electricity in the first capacitor61. Further, the aforementioned voltage step-down chopper circuit steps down the voltage of the bus to produces the effect of preventing an excessive increase in the voltage of the bus from damaging the device.

Likewise, when a failure of the second power supply circuit3boccurs but the first power supply circuit3ais normal, the N-phase voltage step-up/step-down driving circuit201of the voltage step-up/step-down driving circuit2and the first inverter circuit8aoperate normally, and the FWD on the P-phase side in the voltage step-up/step-down circuit7operates normally. Thus, these circuits operating normally and the choke coil63constitute a voltage step-up chopper circuit which in turn steps up the voltage of the second capacitor62. Thus, the first inverter circuit8aoperates normally because of the supply of electric power from the second capacitor62and the control signal from the first inverter driving circuit1ato be able to drive the first three-phase motor9a.

As described above, when the failure of the second power supply circuit3boccurs but the first power supply circuit3ais normal, the first inverter circuit8ais able to continue to drive the first three-phase motor9a.

Circuit Layout

Next, a circuit layout in the vehicle-mounted motor driving control board10will be described with reference toFIGS. 6 and 7.FIG. 6is a diagram showing a schematic circuit layout and a supply system for control voltages in the vehicle-mounted motor driving control board10.FIG. 7is a schematic perspective view of the vehicle-mounted motor driving control board10and a semiconductor module6connected thereto.

The vehicle-mounted motor driving control board10shown inFIG. 6includes the first power supply circuit3aand the second power supply circuit3bwhich are formed by the DC-DC converter3shown inFIG. 3, and the two power supply circuits3aand3bsupply the control voltages in accordance with the system shown inFIG. 4. In the following description, the power transformer31of the first power supply circuit3ais referred to as a first power transformer31a, and the power transformer31of the second power supply circuit3bis referred to as a second power transformer31b.

As shown inFIG. 6, the first power transformer31aand the second power transformer31bin the vehicle-mounted motor driving control board10are arranged so that the fourth outer edge portions F4in the first power transformer31aand the second power transformer31bare in opposed relation to each other.

Also, a constituent circuit110which constitutes part of the first inverter driving circuit1a, a constituent circuit200which constitutes part of the voltage step-up/step-down driving circuit2, and a constituent circuit120which constitutes part of the second inverter driving circuit1bare arranged in order from the second outer edge portion F2side of the first power transformer31ain a first region A1on the side where the third outer edge portion F3of the first power transformer31aand the first outer edge portion F1of the second power transformer31bare positioned.

More specifically, the first P-phase inverter driving circuit112, the N-phase voltage step-up/step-down driving circuit201and the second N-phase inverter driving circuit121are arranged in the first region A1in order from the second outer edge portion F2side of the first power transformer31a.

Each of the constituent circuits arranged in the first region A1is connected to any of the following: the secondary coils311to314arranged on the third outer edge portion F3side in the first power transformer31aand the secondary coil315arranged on the first outer edge portion F1side in the second power transformer31b.

More specifically, the first P-phase inverter driving circuit112is connected to the first secondary coil311, the second secondary coil312and the third secondary coil313in the first power transformer31a. The N-phase voltage step-up/step-down driving circuit201is connected to the fourth secondary coil314in the first power transformer31a. The second N-phase inverter driving circuit121is connected to the fifth secondary coil315in the second power transformer31b.

Also, a constituent circuit110which constitutes the remainder of the first inverter driving circuit1a, a constituent circuit200which constitutes the remainder of the voltage step-up/step-down driving circuit2, and a constituent circuit120which constitutes the remainder of the second inverter driving circuit1bare arranged in order from the second outer edge portion F2side of the first power transformer31ain a second region A2on the side where the first outer edge portion F1in the first power transformer31aand the third outer edge portion F3in the second power transformer31bare positioned.

More specifically, the first N-phase inverter driving circuit111, the P-phase voltage step-up/step-down driving circuit202and the second P-phase inverter driving circuit122are arranged in the second region A2in order from the second outer edge portion F2side of the first power transformer31a.

Each of the constituent circuits arranged in the second region A2is connected to any of the following: the secondary coil315arranged on the first outer edge portion F1side in the first power transformer31aand the secondary coils311to314arranged on the third outer edge portion F3side in the second power transformer31b.

More specifically, the first N-phase inverter driving circuit111is connected to the fifth secondary coil315in the first power transformer31a. The P-phase voltage step-up/step-down driving circuit202is connected to the fourth secondary coil314in the second power transformer31b. The second P-phase inverter driving circuit122is connected to the third secondary coil313, the second secondary coil312and the first secondary coil311in the second power transformer31b.

Although the constituent circuits are connected through the rectifier circuits33shown inFIG. 3to the secondary coils, circuits other than the power transformers31constituting the two power supply circuit3aand3bare not shown inFIG. 6.

The use of the circuit layout shown inFIG. 6achieves very short electric power supply lines between the first and second power transformers31aand31b, and the two inverter driving circuits1a,1band the voltage step-up/step-down driving circuit2.

As shown inFIG. 7, the vehicle-mounted motor driving control board10is provided with a plurality of connection terminals1pconnected to the semiconductor module6including the voltage step-up/step-down circuit7and the two inverter circuits8aand8b. These connection terminals1pestablish electrical connections between the two inverter driving circuits1a,1band the voltage step-up/step-down driving circuit2in the vehicle-mounted motor driving control board10, and the two inverter circuits8a,8band the voltage step-up/step-down circuit7in the semiconductor module6to transmit the driving signals.

The vehicle-mounted motor driving control board10shown inFIG. 6is provided with the connection terminals1parranged in a line on the back side of the first region A1and the connection terminals1parranged in a line on the back side of the second region A2. Specifically, the connection terminals1pfor supplying the driving signals to the voltage step-up/step-down circuit7and to the two inverter circuits8aand8bin the vehicle-mounted motor driving control board10are provided on the back side of the circuits which generate the corresponding driving signals. The circuit layout shown inFIG. 6is suitable for the arrangement of the connection terminals1pin two lines in the vehicle-mounted motor driving control board10.

Effects

The vehicle-mounted motor driving control board10described above achieves the reductions in size and cost in corresponding relation to the omission of one power supply circuit, as compared with a conventional board including three power supply circuits. Further, in the vehicle-mounted motor driving control board10, the two power supply circuits3aand3bshare the supply of electric power (DC voltages) to the plurality of constituent circuits200,110and120constituting the voltage step-up/step-down driving circuit and the two inverter driving circuits. Thus, if a failure of one of the power supply circuits occurs, the vehicle-mounted motor driving control board10is capable of implementing the function of continuing the operation of part of the two inverter circuits (the redundancy of the power supply).

For example, as shown inFIG. 4, the first power supply circuit3asupplies electric power to the N-phase voltage step-up/step-down driving circuit201and all constituent circuits110of the first inverter driving circuit1a, and the second power supply circuit3bsupplies electric power to the P-phase voltage step-up/step-down driving circuit202and all constituent circuits120of the second inverter driving circuit1b. This allows part of the functions such as the function of storing electricity in the first capacitor61by means of the second inverter circuit8bfor electric power regeneration to be continued if a failure of one of the first power supply circuit3aand the second power supply circuit3boccurs.

When the position and connection destination of the N-phase voltage step-up/step-down driving circuit202and the position and connection destination of the P-phase voltage step-up/step-down driving circuit201are interchanged in the configurations shown inFIGS. 4 and 6, effects similar to those obtained by the configurations shown inFIGS. 4 and 6are produced. In this case, the P-phase voltage step-up/step-down driving circuit202receives the supply of electric power (control voltage) from the fourth secondary coil314of the first power transformer31ain the first power supply circuit3a, and the N-phase voltage step-up/step-down driving circuit201receives the supply of electric power from the fourth secondary coil314of the second power transformer31bin the second power supply circuit3b.

Further, when the first power supply circuit3aand the second power supply circuit3bare circuits identical in specs with each other in the vehicle-mounted motor driving control board10, the further reduction in cost is achieved.

When the connection terminals1pare arranged in two lines in the vehicle-mounted motor driving control board10and the circuit layout shown inFIG. 6is employed, the path of supply of electric power from the two power supply circuits3aand3bto the driving circuits is shortened. This achieves more stable supply of electric power. Further, the path of supply of the driving signals from the driving circuits to the voltage step-up/step-down circuit7and the two inverter circuits8aand8bis shortened. This achieves more stable supply of the driving signals.

Second Embodiment

Next, a vehicle-mounted motor driving control board10A according to a second embodiment of the present invention will be described with reference toFIGS. 8 and 9.FIG. 8is a diagram showing a schematic circuit layout and a supply system for control voltages in the vehicle-mounted motor driving control board10A.FIG. 9is a schematic perspective view of the vehicle-mounted motor driving control board10A and the semiconductor module6connected thereto.

The vehicle-mounted motor driving control board10A differs only in circuit layout from the vehicle-mounted motor driving control board10shown inFIGS. 1 to 7. Like reference numerals and characters are used to designate components inFIGS. 8 and 9identical with those shown inFIGS. 1 to 7. Only differences in the vehicle-mounted motor driving control board10A from the vehicle-mounted motor driving control board10will be described below.

The vehicle-mounted motor driving control board10A includes the first power supply circuit3aand the second power supply circuit3bwhich are formed by the DC-DC converter3shown inFIG. 3, and these two power supply circuits3aand3bsupply the control voltages in accordance with the system shown inFIG. 4.

As shown inFIG. 8, the first power transformer31aand the second power transformer31bin the vehicle-mounted motor driving control board10A are arranged so that the third outer edge portions F3in the first power transformer31aand the second power transformer31bare in opposed relation to each other.

Also, a constituent circuit110which constitutes part of the first inverter driving circuit1a, a constituent circuit110which constitutes the remainder of the first inverter driving circuit1a, and a constituent circuit200which constitutes part of the voltage step-up/step-down driving circuit2are arranged in order from the first outer edge portion F1side of the first power transformer31ain a first region A3including a region opposed to the second outer edge portion F2of the first power transformer31a.

More specifically, the first N-phase inverter driving circuit111, the first P-phase inverter driving circuit112and the N-phase voltage step-up/step-down driving circuit201are arranged in the first region A3in order from the first outer edge portion F1side of the first power transformer31a.

Each of the constituent circuits arranged in the first region A3is connected to any of the following: the secondary coils311to315in the first power transformer31a.

More specifically, the first N-phase inverter driving circuit111is connected to the fifth secondary coil315in the first power transformer31a. The first P-phase inverter driving circuit112is connected to the first secondary coil311, the second secondary coil312and the third secondary coil313in the first power transformer31a. The N-phase voltage step-up/step-down driving circuit201is connected to the fourth secondary coil314in the first power transformer31a.

Also, a constituent circuit120which constitutes part of the second inverter driving circuit1b, a constituent circuit120which constitutes the remainder of the second inverter driving circuit1b, and a constituent circuit200which constitutes the remainder of the voltage step-up/step-down driving circuit2are arranged in order from the first outer edge portion F1side of the second power transformer31bin a second region A4including a region opposed to the fourth outer edge portion F4in the second power transformer31b. As shown inFIG. 8, the second region A4is a region adjacent to the first region A3.

More specifically, the second N-phase inverter driving circuit121, the second P-phase inverter driving circuit122and the P-phase voltage step-up/step-down driving circuit202are arranged in the second region A4in order from the first outer edge portion F1side of the second power transformer31b.

Each of the constituent circuits arranged in the second region A4is connected to any of the following: the secondary coils311to315in the second power transformer31b.

More specifically, the second N-phase inverter driving circuit121is connected to the fifth secondary coil315in the second power transformer31b. The second P-phase inverter driving circuit122is connected to the second secondary coil312, the third secondary coil313and the fourth secondary coil314in the second power transformer31b. The P-phase voltage step-up/step-down driving circuit202is connected to the first secondary coil311in the second power transformer31b.

Although the constituent circuits are connected through the rectifier circuits33shown inFIG. 3to the secondary coils, circuits other than the power transformers31constituting the two power supply circuit3aand3bare not shown inFIG. 8.

The use of the circuit layout shown inFIG. 8achieves short electric power supply lines between the first and second power transformers31aand31b, and the two inverter driving circuits1a,1band the voltage step-up/step-down driving circuit2in such a state that the constituent circuits110and120of the two inverter driving circuits1aand1band the constituent circuits200of the voltage step-up/step-down driving circuit2are arranged in a line.

As shown inFIG. 9, the vehicle-mounted motor driving control board10A is provided with the plurality of connection terminals1pconnected to the semiconductor module6. These connection terminals1pestablish electrical connections between the two inverter driving circuits1a,1band the voltage step-up/step-down driving circuit2in the vehicle-mounted motor driving control board10A, and the two inverter circuits8aand8band the voltage step-up/step-down circuit7in the semiconductor module6to transmit the driving signals.

The vehicle-mounted motor driving control board10A shown inFIG. 8is provided with the connection terminals1parranged in a line on the back side of the first region A3and the second region A4. Specifically, the connection terminals1pfor supplying the driving signals to the voltage step-up/step-down circuit7and to the two inverter circuits8aand8bin the vehicle-mounted motor driving control board10A are provided on the back side of the circuits which generate the corresponding driving signals. The circuit layout shown inFIG. 8is suitable for the arrangement of the connection terminals1pin a line in the vehicle-mounted motor driving control board10A.

Effects

When the vehicle-mounted motor driving control board10A is employed, effects similar to those obtained when the vehicle-mounted motor driving control board10is employed are produced.

When the connection terminals1pare arranged in a line in the vehicle-mounted motor driving control board10A and the circuit layout shown inFIG. 8is employed, the path of supply of electric power from the two power supply circuits3aand3bto the driving circuits is shortened. This achieves more stable supply of electric power. Further, the path of supply of the driving signals from the driving circuits to the voltage step-up/step-down circuit7and the two inverter circuits8aand8bis shortened. This achieves more stable supply of the driving signals.

Third Embodiment

Next, a vehicle-mounted motor driving control board10B according to a third embodiment of the present invention will be described with reference toFIG. 10.FIG. 10is a diagram showing a supply system for control voltages in the vehicle-mounted motor driving control board10B.

The vehicle-mounted motor driving control board10B differs from the vehicle-mounted motor driving control board10shown inFIGS. 1 to 7in the supply system for electric power (control voltages) from the two power supply circuits3aand3bto the driving circuits. Like reference numerals and characters are used to designate components inFIG. 10identical with those shown inFIGS. 1 to 7. Only differences in the vehicle-mounted motor driving control board10B from the vehicle-mounted motor driving control board10will be described below.

In the vehicle-mounted motor driving control board10B, the two power supply circuits3aand3bsupply the control voltages to the constituent circuits of the driving circuits in accordance with the system shown inFIG. 10.

As shown inFIG. 10, the first power supply circuit3ain the vehicle-mounted motor driving control board10B supplies electric power (control voltages) to the N-phase voltage step-up/step-down driving circuit201and the P-phase voltage step-up/step-down driving circuit202which constitute the voltage step-up/step-down driving circuit2, to the first N-phase inverter driving circuit111which constitutes part of the first inverter driving circuit1a, and to the second N-phase inverter driving circuit121which constitutes part of the second inverter driving circuit1b.

The second power supply circuit3bin the vehicle-mounted motor driving control board10B, on the other hand, supplies electric power (control voltages) to the first P-phase inverter driving circuit112which constitutes the remainder of the first inverter driving circuit1a, and to the second P-phase inverter driving circuit122which constitutes the remainder of the second inverter driving circuit1b.

Effects

When the vehicle-mounted motor driving control board10B is employed, effects of the reductions in size and cost in corresponding relation to the omission of one power supply circuit are produced as in the cases where the vehicle-mounted motor driving control boards10and10A are employed.

Various patterns in addition to those shown inFIGS. 4, 6 and 8can be contemplated as the pattern of the supply of the control voltages from the two power supply circuits3aand3bto the constituent circuits of the driving circuits.

Fourth Embodiment

Next, a vehicle-mounted motor driving control board10C according to a fourth embodiment of the present invention will be described with reference toFIG. 11.FIG. 11is a schematic block diagram of a vehicle-mounted motor driving device including the vehicle-mounted motor driving control board10C.

The vehicle-mounted motor driving control board10C is configured such that a protection circuit4is added, as compared with any one of the vehicle-mounted motor driving control boards10,10A and10B shown inFIGS. 1 to 10. Like reference numerals and characters are used to designate components inFIG. 11identical with those shown inFIGS. 1 to 10. Only differences in the vehicle-mounted motor driving control board10C from the vehicle-mounted motor driving control boards10,10A and10B will be described below.

As shown inFIG. 11, the vehicle-mounted motor driving control board10C further includes the protection circuit4in addition to the components provided in the vehicle-mounted motor driving control boards10,10A and10B.

A state signal indicative of the state of each of the voltage step-up/step-down circuit7and the two inverter circuits8aand8bis inputted from each of the voltage step-up/step-down circuit7and the two inverter circuits8aand8bto the protection circuit4. The state signal is, for example, a detection signal of a sensor provided in each circuit. The sensor provided in each circuit includes, for example, one or more of the following: a voltage sensor, a current sensor and a temperature sensor.

When a previously determined abnormal condition based on the state signal obtained from each of the voltage step-up/step-down circuit7and the two inverter circuits8aand8bis satisfied, the protection circuit4changes a driving signal to be outputted to a circuit corresponding to the abnormal condition among the voltage step-up/step-down circuit7and the two inverter circuits8aand8bto a previously determined fail safe signal (safe side control signal). It is needless to say that the driving signal is a signal outputted from each of the voltage step-up/step-down driving circuit2and the inverter driving circuits1aand1bto a corresponding one of the voltage step-up/step-down circuit7and the two inverter circuits8aand8b.

For example, when the state signal obtained from any one of the voltage step-up/step-down circuit7and the two inverter circuits8aand8bsatisfies the previously determined abnormal condition, the protection circuit4changes the driving signal to be outputted to the circuit from which the state signal is inputted to the previously determined fail safe signal. That is, when the abnormal condition based on the inputted state signal is satisfied, the protection circuit4changes the driving signal to be outputted to a circuit corresponding to the satisfied abnormal condition among the voltage step-up/step-down circuit7and the two inverter circuits8aand8bto the fail safe signal.

The fail safe signal is a signal for turning off the IGBT of a power switching circuit corresponding to the satisfied abnormal condition. The abnormal condition is a condition for determining that an overvoltage, an overcurrent or an excessively high temperature occurs, for example, based on the state signal.

Effects

When the vehicle-mounted motor driving control board10C is employed, effects similar to those obtained when the vehicle-mounted motor driving control board10is employed are produced.

Further, when the vehicle-mounted motor driving control board10C is employed, damages to the power switching circuits in the voltage step-up/step-down circuit7and the two inverter circuits8aand8bare avoided. This improves the reliability of the device.

The embodiments according to the present invention may be freely combined within the scope of the invention or the embodiments may be changed and dispensed with, as appropriate.