Patent Publication Number: US-2022224271-A1

Title: Energy conversion apparatus, motor, power system, and vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese Patent Application No. 202110354753.2, filed on Mar. 31, 2021, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     Embodiments of this application relate to the field of energy technologies, and in particular, to an energy conversion apparatus, a motor, a power system, and a vehicle. 
     BACKGROUND 
     In the field of energy technologies, a charging technology for electric vehicles is always an important research direction of researchers. In addition to a charger and a battery that are related to charging, a plurality of motors are further mounted on the electric vehicle, for example, a motor that drives the vehicle to travel and a motor in an air conditioner compressor. These functional components on the electric vehicle are all separately distributed, resulting in a complex structure layout, a low integration level, a large volume, and high costs of the electric vehicle. 
     To increase the vehicle integration level, simplify the structure layout of the electric vehicle, and reduce the costs and volume of the electric vehicle, it is necessary to integrate a charging function and a motor drive function of the electric vehicle. 
     SUMMARY 
     Embodiments of this application provide an energy conversion apparatus, a motor, a power system, and a vehicle. The apparatus integrates a charging function and a motor drive function. When the apparatus is installed on an electric vehicle, a vehicle integration level can be increased, a structure layout of the electric vehicle can be simplified, and costs and a volume of the electric vehicle can be reduced. 
     According to a first aspect, an embodiment of this application provides an energy conversion apparatus, including a three-phase bridge arm converter, a motor winding, a two-phase two-bridge-arm converter, and a transformer. A direct current port of the three-phase bridge arm converter is connected to a battery; an alternating current port of the three-phase bridge arm converter is connected to the motor winding; a direct current port of the two-phase two-bridge-arm converter is connected to the battery; an alternating current port of the two-phase two-bridge-arm converter is connected to a secondary-side winding of the transformer; and a primary-side winding of the transformer is connected to an alternating current charging port. 
     The energy conversion apparatus provided in the first aspect of this application may integrate a motor drive function by using the three-phase bridge arm converter and the motor winding, and integrate an alternating current charging function by using the two-phase two-bridge-arm converter and the transformer. In this way, the energy conversion apparatus can integrate the charging function and the motor drive function. When the energy conversion apparatus is installed on an electric vehicle, a vehicle integration level can be increased, a structure layout of the electric vehicle can be simplified, and costs and a volume of the electric vehicle can be reduced. 
     According to a second aspect, an embodiment of this application provides an energy conversion apparatus, including a three-phase bridge arm converter, a motor winding, and a transformer. A direct current port of the three-phase bridge arm converter is connected to a battery; an alternating current port of the three-phase bridge arm converter is connected to the motor winding; two bridge arms of the three-phase bridge arm converter are connected to a secondary-side winding of the transformer through a first switch group, and the first switch group is configured to control connection and disconnection between the transformer and the two bridge arms of the three-phase bridge arm converter; a second switch group is further disposed between the motor winding and the two bridge arms of the three-phase bridge arm converter, and the second switch group is configured to control connection and disconnection between the motor winding and the two bridge arms of the three-phase bridge arm converter; and a primary-side winding of the transformer is connected to an alternating current charging port. 
     The energy conversion apparatus provided in the second aspect of this application may integrate a motor drive function by using the three-phase bridge arm converter and the motor winding, implement an alternating current charging function by reusing the two bridge arms of the three-phase bridge arm converter, and implement conversion between a motor drive mode and an alternating current charging mode by using the first switch group and the second switch group. Therefore, the energy conversion apparatus can not only integrate the charging function and the motor drive function, but also reuse some circuits. This further increases an integration level and reduces a volume. 
     With reference to the second aspect, in an implementation provided in this embodiment of this application, the first switch group and the second switch group include a flip-flop K 1  and a flip-flop K 2 ; one end of the flip-flop K 1  is connected to an alternating current port of a first bridge arm of a two-phase two-bridge-arm converter, and the other end of the flip-flop K 1  includes two contacts respectively connected to the motor winding and a secondary-side winding of the transformer; and one end of the flip-flop K 2  is connected to an alternating current port of a second bridge arm of the two-phase two-bridge-arm converter, and the other end of the flip-flop K 2  includes two contacts respectively connected to the motor winding and the secondary-side winding of the transformer. In this implementation, functions of the first switch group and the second switch group are implemented by using two flip-flops. This further increases an integration level and reduces a volume. 
     According to a third aspect, an embodiment of this application provides an energy conversion apparatus, including a three-phase bridge arm converter, a motor winding, a bridge arm circuit, and a transformer. A direct current port of the three-phase bridge arm converter is connected to a battery; an alternating current port of the three-phase bridge arm converter is connected to the motor winding; an alternating current port of one bridge arm of the three-phase bridge arm converter is further connected to a secondary-side winding of the transformer; a direct current port of the bridge arm circuit is connected to the battery; an alternating current port of the bridge arm circuit is connected to the secondary-side winding of the transformer; and a primary-side winding of the transformer is connected to an alternating current charging port. 
     The energy conversion apparatus provided in the third aspect of this application may integrate a motor drive function by using the three-phase bridge arm converter and the motor winding, and implement an alternating current charging function by using the bridge arm circuit and reusing the bridge arm of the three-phase bridge arm converter. Therefore, the energy conversion apparatus can not only integrate the charging function and the motor drive function, but also reuse some circuits. This further increases an integration level and reduces a volume. 
     With reference to the third aspect, in an implementation of this embodiment of this application, the bridge arm circuit is two capacitors connected in series, two diodes connected in series, or two switching transistors connected in series. This implementation provides a plurality of implementation solutions, so that the solutions provided in embodiments of this application are more comprehensive. 
     According to a fourth aspect, an embodiment of this application provides an energy conversion apparatus, including a three-phase bridge arm converter, a motor winding, and a transformer. A direct current port of the three-phase bridge arm converter is connected to a battery; an alternating current port of the three-phase bridge arm converter is connected to the motor winding; an alternating current port of one bridge arm of the three-phase bridge arm converter is specifically connected to the motor winding through a first switch and connected to one end of a secondary-side winding of the transformer through a second switch; the other end of the secondary-side winding of the transformer is connected to a busbar end of the motor winding through a third switch; and a primary-side winding of the transformer is connected to an alternating current charging port. 
     The energy conversion apparatus provided in the fourth aspect of this application may integrate a motor drive function by using the three-phase bridge arm converter and the motor winding, and implement an alternating current charging function by reusing three bridge arms of the three-phase bridge arm converter as a converter. Therefore, the energy conversion apparatus can not only integrate the charging function and the motor drive function, but also reuse some circuits. This further increases an integration level and reduces a volume. 
     With reference to the fourth aspect, in an implementation of this embodiment of this application, the first switch and the second switch are specifically a flip-flop K 3 ; and one end of the flip-flop K 3  is connected to the alternating current port of the bridge arm of the three-phase bridge arm converter, and the other end of the flip-flop K 3  includes two contacts respectively connected to one winding in the motor winding and the end of the secondary-side winding of the transformer. In this implementation, functions of the first switch and the second switch are implemented by using one flip-flop. This further increases an integration level and reduces a volume. 
     According to a fifth aspect, an embodiment of this application provides an energy conversion apparatus, including a three-phase bridge arm converter, a motor winding, a bridge arm circuit, and a transformer. A direct current port of the three-phase bridge arm converter is connected to a battery; an alternating current port of the three-phase bridge arm converter is connected to the motor winding; a direct current port of the bridge arm circuit is connected to the battery, and an alternating current port of the bridge arm circuit is connected to one end of a secondary-side winding of the transformer; the other end of the secondary-side winding of the transformer is connected to a busbar end of the motor winding through a third switch; and a primary-side winding of the transformer is connected to an alternating current charging port. 
     The energy conversion apparatus provided in the fifth aspect of this application may integrate a motor drive function by using the three-phase bridge arm converter and the motor winding, and implement an alternating current charging function by using the bridge arm circuit and reusing the three-phase bridge arm converter and the motor winding. Therefore, the energy conversion apparatus can not only integrate the charging function and the motor drive function, but also reuse some circuits. This further increases an integration level and reduces a volume. 
     With reference to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect, in an implementation of embodiments of this application, a fourth switch is disposed between the primary-side winding of the transformer and the alternating current charging port, and is configured to control connection and disconnection between the primary-side winding of the transformer and the alternating current charging port. In this implementation, the connection and disconnection between the primary-side winding of the transformer and the alternating current charging port are controlled by using the fourth switch, so that the solutions provided in embodiments of this application are more comprehensive. 
     With reference to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect, in an implementation of embodiments of this application, an alternating current filter is disposed between the primary-side winding of the transformer and the alternating current charging port. In this implementation, an alternating current that is input from the alternating current charging port is filtered by using the alternating current filter, so that the solutions provided in embodiments of this application are more comprehensive. 
     With reference to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect, in an implementation of embodiments of this application, the transformer is specifically a power frequency transformer. In this implementation, the power frequency transformer is used as the transformer, so that the solutions provided in embodiments of this application are more comprehensive. 
     According to a sixth aspect, an embodiment of this application provides a motor. The motor includes a housing, and the energy conversion apparatus according to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect is accommodated in the housing. 
     According to a seventh aspect, an embodiment of this application provides a power system, including a motor and the energy conversion apparatus according to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect. A motor winding of the energy conversion apparatus is configured to drive the motor. 
     According to an eighth aspect, an embodiment of this application provides a vehicle, including the energy conversion apparatus according to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect, the motor according to the sixth aspect, or the power system according to the seventh aspect. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram of an energy conversion apparatus according to an embodiment of this application; 
         FIG. 2  is a schematic diagram of an integration manner according to an embodiment of this application; 
         FIG. 3 a    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; 
         FIG. 3 b    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; 
         FIG. 4 a    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; 
         FIG. 4 b    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; 
         FIG. 4 c    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; 
         FIG. 5  is a schematic diagram of another energy conversion apparatus according to an embodiment of this application; and 
         FIG. 6  is a schematic diagram of another energy conversion apparatus according to an embodiment of this application. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of this application provide an energy conversion apparatus, a motor, a power system, and a vehicle. The apparatus integrates a charging function and a motor drive function. When the apparatus is installed on an electric vehicle, a vehicle integration level can be increased, a structure layout of the electric vehicle can be simplified, and costs and a volume of the electric vehicle can be reduced. 
     In the specification, claims, and accompanying drawings of this application, the terms “first”, “second”, “third”, “fourth”, and the like (if existent) are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence. It should be understood that the data termed in such a way are interchangeable in proper circumstances, so that embodiments described herein can be implemented in an order other than the order illustrated or described herein. Moreover, the terms “include”, “correspond to” and any other variants mean to cover the non-exclusive inclusion, for example, a process, method, system, product, or device that includes a list of steps or units is not necessarily limited to those expressly listed steps or units, but may include other steps or units not expressly listed or inherent to such a process, method, system, product, or device. 
     In embodiments of this application, words such as “example” or “for example” are used to indicate examples, instances, or descriptions. Any embodiment or solution described as “example” or “for example” in embodiments of this application is not to be construed as being more preferred or advantageous than other embodiments or solutions. Exactly, use of the word “example” or “for example” or the like is intended to present a relative concept in a specific manner. 
     For clear and brief description of the following embodiments, a related technology is briefly described first. 
     There are usually two types of solutions for integration of a charging function and a motor drive function of an electric vehicle. One type of solution is a non-isolated-type integrated charging solution, and non-isolated-type charging means that no transformer is used for isolation between a charging port and a high-voltage battery. To be specific, in this charging solution, the high-voltage battery and the charging port have a direct electrical connection relationship. Consequently, there is a safety risk. At present, this non-isolated-type charging solution is basically not used on the electric vehicle. 
     The other type of solution is an isolated-type integrated charging solution. To be specific, at least one transformer is used for isolation on a transformer circuit between a charging port and a high-voltage battery. After input from an alternating current port, rectification is performed and then a voltage is boosted. Subsequently, a next converter performs isolated conversion to charge the high-voltage battery. In this isolated-type charging solution, both a separate charging solution and an integrated charging solution are main forms of electric vehicle charging at present. 
     However, in a current solution, an integration level is relatively low, costs are relatively high, and a volume is relatively large. An embodiment of this application provides an energy conversion apparatus. The apparatus integrates a charging function and a motor drive function. When the apparatus is installed on an electric vehicle, a vehicle integration level can be increased, a structure layout of the electric vehicle can be simplified, and costs and a volume of the electric vehicle can be reduced. 
       FIG. 1  is a schematic diagram of an energy conversion apparatus according to an embodiment of this application. The energy conversion apparatus integrates a charging function and a motor drive function. The energy conversion apparatus includes a three-phase bridge arm converter  102 , a motor winding  104 , a two-phase two-bridge-arm converter  103 , and a transformer  105 . A direct current port of the three-phase bridge arm converter  102  is connected to a battery  101 , an alternating current port of the three-phase bridge arm converter  102  is connected to the motor winding  104 , a primary-side winding of the transformer  105  is connected to an alternating current charging port  106 , a secondary-side winding of the transformer  105  is connected to an alternating current port of the two-phase two-bridge-arm converter  103 , and a direct current port of the two-phase two-bridge-arm converter  103  is connected to the direct current port of the three-phase bridge arm converter  102 . The following describes components of the energy conversion apparatus in detail. 
     1. Battery  101   
     In this embodiment of this application, two ends of the battery  101  each may be used as an output port or an input port. 
     In this embodiment of this application, the battery  101  may be specifically a high-voltage battery. With development of electric vehicle technologies, a requirement for long endurance is increasingly high. Therefore, a higher requirement is imposed on a battery capacity, and a battery voltage is also increasingly high. Therefore, high-voltage batteries are used for more electric vehicles to provide energy for traveling of the vehicles. The battery  101  in this embodiment of this application may be a high-voltage battery, and is applicable to an electric vehicle with a higher requirement. 
     2. Three-Phase Bridge Arm Converter  102   
     In this embodiment of this application, the three-phase bridge arm converter  102  may be specifically a three-phase three-bridge-arm converter, a three-phase four-bridge-arm converter, or the like. This is not limited in this embodiment of this application. For example, when the three-phase bridge arm converter  102  is a three-phase three-bridge-arm converter, the three-phase bridge arm converter  102  includes three bridge arms, and each bridge arm may be two switching transistors connected in series. A port for connecting the three bridge arms in parallel is the direct current port of the three-phase bridge arm converter  102 , and is configured to connect to a direct current device. In this embodiment of this application, the direct current port of the three-phase bridge arm converter  102  is connected to the battery  101 . Intermediate end points of the three bridge arms are three alternating current ports of the three-phase bridge arm converter  102 , and are configured to connect to the motor winding  104 . When an alternating current passes through the motor winding  104 , a corresponding motor is driven. 
     In some embodiments, a switching transistor used for the three-phase bridge arm converter  102  may be a transistor connected to a diode in parallel, a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or the like. This is not limited in embodiments of this application. 
     3. Two-Phase Two-Bridge-Arm Converter  103   
     In this embodiment of this application, the two-phase two-bridge-arm converter  103  may include two bridge arms, and each bridge arm may include two switching transistors connected in series. A parallel connection end of the two bridge arms is the direct current port of the two-phase two-bridge-arm converter  103 . The direct current port of the two-phase two-bridge-arm converter  103  may be connected to the battery  101 . Intermediate end points of the two bridge arms are two alternating current ports of the two-phase two-bridge-arm converter  103 . The two alternating current ports of the two-phase two-bridge-arm converter  103  are connected to two ends of the secondary-side winding of the transformer  105 . 
     In some embodiments, a power factor correction (PFC) inductor is further connected in series between one alternating current port of the two-phase two-bridge-arm converter  103  and the secondary-side winding of the transformer  105 , and is configured to cooperate with the two-phase two-bridge-arm converter  103  to implement a boost function. 
     In this embodiment of this application, a switching transistor used for the two-phase two-bridge-arm converter  103  may be a transistor connected to a freewheeling diode in parallel, an MOS transistor, an IGBT, or the like. This is not limited in this embodiment of this application. A type of the switching transistor used for the two-phase two-bridge-arm converter  103  may be the same as or different from a type of the switching transistor used for the three-phase bridge arm converter  102 . This is not limited in this embodiment of this application. 
     4. Motor Winding  104   
     In this embodiment of this application, the motor winding  104  is a winding of a motor on an electric vehicle. Specifically, the motor winding  104  may be a stator winding. 
     The motor in this embodiment of this application may be a motor that drives the vehicle to travel on the electric vehicle, or may be a motor in a compressor used by an air conditioner on the electric vehicle. Certainly, another similar motor is also included in the motor in this embodiment of this application. A type of the motor is not limited in this embodiment of this application. Actually, because a power of the air conditioner compressor is equivalent to that of an alternating current charger of the electric vehicle, higher utilization can be achieved by integrating the charger and the compressor. 
     5. Transformer  105   
     In this embodiment of this application, the transformer  105  may be a power frequency transformer, and is configured to isolate the alternating current charging port  106  from the battery  101 , so that the alternating current charging port  106  and the battery  101  are not directly electrically connected. This is safer. 
     In this embodiment of this application, the two ends of the secondary-side winding of the transformer  105  are connected to the two alternating current ports of the two-phase two-bridge-arm converter  103 , and the primary-side winding of the transformer  105  is connected to the alternating current charging port  106 , to isolate an alternating current that is input from the alternating current charging port  106  and then transmit the alternating current to the two-phase two-bridge-arm converter  103 . Then, the two-phase two-bridge-arm converter  103  may convert the alternating current into a direct current and transmit the direct current to the battery  101 , to charge the battery  101 . 
     In this embodiment of this application, mutual interference between a winding of the transformer  105  and a winding of the motor winding  104  should be avoided as much as possible. However, in some embodiments, the transformer  105  and the motor winding  104  are integrated into one motor together, and are relatively close to each other. Therefore, an embodiment of this application provides an integration manner, as shown in  FIG. 2 , to avoid mutual interference between the winding of the transformer  105  and the winding of the motor winding  104 .  FIG. 2  is a schematic diagram of an integration manner according to an embodiment of this application. A motor stator corresponding to the motor winding  104  is disposed coaxially with a transformer iron core corresponding to the transformer  105  in an aligned manner. The motor winding is wound on the motor stator, and the primary-side winding and the secondary-side winding of the transformer  105  are wound on the transformer iron core. In this case, interference between the winding of the transformer  105  and the winding of the motor winding  104  is relatively weak. 
     In some embodiments, an alternating current filter  107  is disposed between the primary-side winding of the transformer  105  and the alternating current charging port  106 , and is configured to perform filtering on an alternating current that is input from the alternating current charging port  106 . The alternating current filter  107  is similar to a conventional alternating current filter device. Details are not described herein. 
     In some embodiments, a switch  108  is disposed between the primary-side winding of the transformer  105  and the alternating current charging port  106  to implement connection or disconnection between the energy conversion apparatus and the alternating current charging port  106 . As shown in  FIG. 1 , the switch  108  may be disposed between one end of the primary-side winding of the transformer  105  and one port of the alternating current charging port  106 . It may be understood that both the alternating current filter  107  and the switch  108  may be disposed between the primary-side winding of the transformer  105  and the alternating current charging port  106 . 
     6. Alternating Current Charging Port  106   
     In this embodiment of this application, the alternating current charging port  106  is configured to connect to a power grid or connect to an alternating current charging pile. For example, after the alternating current charging port  106  is connected to the alternating current charging pile, electric energy in the alternating current charging pile may be input to the energy conversion apparatus through the alternating current charging port  106 , to charge the battery  101 . 
     It may be understood that the alternating current charging port  106  may be in a shape of a standard charging port, or may be in a form of a fast charging port. In addition, a protocol supported by the alternating current charging port  106  may be a standard charging protocol or a fast charging protocol of electric vehicles. In this embodiment of this application, a shape, a size, a supported protocol, and the like of the alternating current charging port  106  are not limited. 
     In this embodiment of this application, the alternating current filter  107  may be disposed between the alternating current charging port  106  and the transformer  105 . The alternating current filter  107  is similar to another alternating current filter device. Details are not described herein. 
     In this embodiment of this application, the switch  108  may be disposed between the alternating current charging port  106  and the transformer  105 , to control connection and disconnection between the alternating current charging port  106  and the transformer  105 . 
     In this embodiment of this application, both the alternating current filter  107  and the switch  108  may be disposed. This is not limited in this embodiment of this application. 
       FIG. 3 a    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application. The energy conversion apparatus includes a battery  301 , a three-phase bridge arm converter  302 , a motor winding  303 , a transformer  304 , and an alternating current charging port  305 . A direct current port of the three-phase bridge arm converter  302  is connected to the battery  301 , an alternating current port of the three-phase bridge arm converter  302  is connected to the motor winding  303 , a primary-side winding of the transformer  304  is connected to the alternating current charging port  305 , and a secondary-side winding of the transformer  304  is connected to two bridge arms of the three-phase bridge arm converter  302 . The following describes components of the energy conversion apparatus in detail. 
     In this embodiment of this application, the battery  301  is similar to the battery  101  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. 
     In this embodiment of this application, the three-phase bridge arm converter  302  may be specifically a three-phase three-bridge-arm converter, a three-phase four-bridge-arm converter, or the like. This is not limited in this embodiment of this application. For example, when the three-phase bridge arm converter  302  is a three-phase three-bridge-arm converter, the three-phase bridge arm converter  302  includes three bridge arms, and each bridge arm may be two switching transistors connected in series. A port for connecting the three bridge arms in parallel is the direct current port of the three-phase bridge arm converter  302 , and is configured to connect to a direct current device. In this embodiment of this application, the direct current port of the three-phase bridge arm converter  302  is connected to the battery  301 . Intermediate end points of the three bridge arms are three alternating current ports of the three-phase bridge arm converter  302 , and are configured to connect to the motor winding  303 . When an alternating current passes through the motor winding  303 , a corresponding motor is driven. 
     In some embodiments, a switching transistor used for the three-phase bridge arm converter  302  may be a transistor connected to a diode in parallel, a metal-oxide-semiconductor field-effect transistor (MOSFET), an IGBT, or the like. This is not limited in embodiments of this application. 
     In addition, in this embodiment of this application, the two bridge arms of the three-phase bridge arm converter  302  may further be used as two bridge arms of an inverter, that is, the two bridge arms of the three-phase bridge arm converter  302  may be connected to the secondary-side winding of the transformer  304 , to invert a direct current at the direct current port to an alternating current and transmit the alternating current to the transformer  304 . Therefore, the three-phase bridge arm converter  302  in this embodiment of this application has two functions: One is to serve as a three-phase inverter by using the three bridge arms to provide electric energy for the motor winding  303 , and the other is to serve as a two-phase inverter to deliver electric energy to the transformer  304 . In actual application, the three-phase bridge arm converter  302  may provide optionality for the foregoing two functions by using two switch groups (a first switch group  307  and a second switch group  308 ). As shown in  FIG. 3 a   , the two bridge arms of the three-phase bridge arm converter  302  may be connected to the secondary-side winding of the transformer  304  through the first switch group  307 , and connected to the motor winding  303  (which may be specifically two windings of the motor winding  303 ) through the second switch group  308 . 
     In the embodiment of  FIG. 3 a   , when the energy conversion apparatus is in an alternating current charging mode, the first switch group  307  may be connected, and the second switch group  308  may be disconnected. After alternating current power that is input from the alternating current charging port  305  is transformed by using the transformer  304 , the alternating current power is converted into direct current power by using the first switch group  307  and the two bridge arms of the three-phase bridge arm converter  302 , to charge the battery  301 . In addition, because the second switch group  308  is disconnected, a current on the three-phase bridge arm converter  302  does not affect the motor winding  303 . When the alternating current charging port  305  is not connected to a charging pile but connected to an electric device, electric energy in the battery  301  may be converted into an alternating current by using the two bridge arms of the three-phase bridge arm converter  302 , to charge/supply power to the device connected to the alternating current charging port  305 . When the energy conversion apparatus is in a motor drive mode, the first switch group  307  may be disconnected, and the second switch group  308  may be connected. In this case, electric energy in the battery  301  may be transmitted to the motor winding  303  through the three-phase bridge arm converter  302  and the second switch group  308 . Because the first switch group  307  is disconnected, electric energy that is input from the alternating current charging port cannot enter the three-phase bridge arm converter  302 . 
     In some other embodiments, in the energy conversion apparatus, the first switch group  307  and the second switch group  308  may be replaced with a flip-flop K 1  and a flip-flop K 2 , as shown in  FIG. 3 b   . An alternating current port of a leftmost bridge arm of the three-phase bridge arm converter  302  is connected to one end of the flip-flop K 1 , and the other end of the flip-flop K 1  has two contacts respectively connected to a leftmost winding of the motor winding  303  and the secondary-side winding of the transformer  304 . An alternating current port of a rightmost bridge arm of the three-phase bridge arm converter  302  is connected to one end of the flip-flop K 2 , and the other end of the flip-flop K 2  has two contacts respectively connected to a rightmost winding of the motor winding  303  and the secondary-side winding of the transformer  304 . In  FIG. 3 b   , when the energy conversion apparatus is in an alternating current charging mode, and the flip-flop K 1  and the flip-flop K 2  each are in contact with by using an upper contact, the alternating current ports of the left and right bridge arms of the three-phase bridge arm converter  302  are connected to the secondary-side winding of the transformer  304 . After alternating current power that is input from the alternating current charging port  305  is transformed by using the transformer  304 , the alternating current power is converted into direct current power by using the flip-flop K 1 , the flip-flop K 2 , and the three-phase bridge arm converter  302 , to charge the battery  301 . When the alternating current charging port  305  is not connected to a charging pile but connected to an electric device, electric energy in the battery  301  may be converted into an alternating current by using the two bridge arms of the three-phase bridge arm converter  302 , to charge/supply power to the device connected to the alternating current charging port  305 . In another case, when the energy conversion apparatus is in a motor drive mode, and the flip-flop K 1  and the flip-flop K 2  each are in contact with by using a lower contact, the alternating current ports of the left and right bridge arms of the three-phase bridge arm converter  302  are connected to the motor winding  303 , and an alternating current port of a middle bridge arm of the three-phase bridge arm converter  302  is also connected to the motor winding  303 . Therefore, electric energy that is output from the battery  301  can be transmitted to the motor winding  303  through the three-phase bridge arm converter  302 , to drive a motor. 
     In the embodiment corresponding to  FIG. 3 a    or  FIG. 3 b   , the alternating current charging port  305  may further be specifically connected to the primary-side winding of the transformer  304  through an alternating current filter  306  and a flip-flop K 3 . The alternating current filter  306  and the flip-flop K 3  are similar to the alternating current filter  107  and the switch  108  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. 
     In this embodiment of this application, the flip-flop K 1  and the flip-flop K 2  each may be replaced with a single-pole double-throw switch, and the flip-flop K 3  may also be replaced with another switch. This is not limited in this embodiment of this application. 
       FIG. 4 a    is a schematic diagram of another energy conversion apparatus according to an embodiment of this application. The energy conversion apparatus includes a battery  401 , a three-phase bridge arm converter  402 , a bridge arm circuit  403 , a motor winding  404 , a transformer  405 , and an alternating current charging port  406 . The battery  401  is similar to the battery  101  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. A connection between the three-phase bridge arm converter  402  and the motor winding  404  is similar to the connection between the three-phase bridge arm converter  102  and the motor winding  104  in the foregoing embodiments corresponding to  FIG. 1 . Details are not described herein again. 
     In this embodiment of this application, one bridge arm (which is a leftmost bridge arm in the example in  FIG. 4 a   , or may be another bridge arm in actual application, where this is not limited in this embodiment of this application) of the three-phase bridge arm converter  402  is further connected to a secondary-side winding of the transformer  405 . 
     In this embodiment of this application, a direct current port of the bridge arm circuit  403  is connected to a direct current port of the three-phase bridge arm converter  402  in parallel, and an alternating current port of the bridge arm circuit  403  is connected to the secondary-side winding of the transformer  405 . In some embodiments, the bridge arm circuit  403  includes two switching transistors connected in series. As shown in  FIG. 4 a   , the bridge arm circuit  403  includes transistors. In actual application, the bridge arm circuit  403  may alternatively include diodes connected in series, as shown in  FIG. 4 b   . Alternatively, the bridge arm circuit  403  may include capacitors connected in series, as shown in  FIG. 4   c.    
     The energy conversion apparatus provided in this embodiment of this application may implement an alternating current charging mode. To be specific, alternating current power that is input from the alternating current charging port  406  may be rectified by using one bridge arm of the three-phase bridge arm converter  402  and the bridge arm circuit  403 , and direct current power is output to the battery  401 , to charge the battery  401 . 
     The energy conversion apparatus provided in this embodiment of this application may implement a motor drive mode. To be specific, the battery  401  outputs direct current power to the three-phase bridge arm converter  402 , the direct current power is inverted into three-phase alternating current power, and the three-phase alternating current power is transmitted to the motor winding  404 , to drive a motor. 
     The energy conversion apparatus provided in embodiments corresponding to  FIG. 4 a    and  FIG. 4 c    may implement an inversion mode. To be specific, direct current power that is output from the battery  401  may be inverted by using one bridge arm of the three-phase bridge arm converter  402  and the bridge arm circuit  403 , and output to the alternating current charging port  406 , to charge/supply power to a device connected to the alternating current charging port  305 . 
     In actual application, in embodiments corresponding to  FIG. 4 a   ,  FIG. 4 b   , and  FIG. 4 c   , an appropriate switch (such as a flip-flop or a relay) may be disposed in a related connection place to control switching between the foregoing modes. This is not limited in embodiments of this application. 
     In embodiments corresponding to  FIG. 4 a   ,  FIG. 4 b   , and  FIG. 4 c   , the alternating current charging port  406  may further be specifically connected to the transformer  405  through an alternating current filter  407  and a flip-flop  408 . The alternating current filter  407  and the flip-flop  408  are similar to the alternating current filter  107  and the switch  108  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. 
       FIG. 5  is a schematic diagram of another energy conversion apparatus according to an embodiment of this application. The energy conversion apparatus includes a battery  501 , a three-phase bridge arm converter  502 , a motor winding  503 , a transformer  504 , and an alternating current charging port  505 . The battery  501  is similar to the battery  101  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. A connection between the three-phase bridge arm converter  502  and the motor winding  503  is similar to that in the related description in the foregoing embodiments corresponding to  FIG. 1 . Details are not described herein again. 
     In this embodiment of this application, a busbar end of the motor winding  503  is further connected to a secondary-side winding of the transformer  504  through a switch K 2 . In actual application, the switch K 2  may be a flip-flop, a relay, or the like. This is not limited in this embodiment of this application. In addition, an alternating current port of a rightmost bridge arm of the three-phase bridge arm converter  502  is connected to the motor winding  503  and the secondary-side winding of the transformer  504  through a switch K 1 . Specifically, one end of the switch K 1  is connected to the alternating current port of the rightmost bridge arm of the three-phase bridge arm converter  502 , and the other end has two contacts respectively connected to the motor winding  503  and the secondary-side winding of the transformer  504 . The switch K 1  may be a flip-flop, a single-pole double-throw switch, or the like. This is not limited in this embodiment of this application. 
     The alternating current charging port  505  may further be specifically connected to a primary-side winding of the transformer  504  through an alternating current filter  506  and a flip-flop K 3 . The alternating current filter  506  and the flip-flop K 3  are similar to the alternating current filter  107  and the switch  108  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. 
     When the energy conversion apparatus shown in  FIG. 5  runs in an alternating current charging mode, the switch K 1  is connected to an upper contact, the switch K 2  is closed, and the switch K 3  is closed. In this case, alternating current power that is input from the alternating current charging port  505  may be transformed by using the transformer  504  and then rectified into direct current power by using the left bridge arm, the middle bridge arm, and the right bridge arm of the three-phase bridge arm converter  502 , and the direct current power is delivered to the battery  501 , to charge the battery  501 . In this case, when the alternating current charging port  505  is not connected to a charging pile but connected to an electric device, electric energy in the battery  501  may be converted into an alternating current by using the three-phase bridge arm converter  502 , to charge/supply power to the device connected to the alternating current charging port  505 . 
     When the energy conversion apparatus shown in  FIG. 5  runs in a motor drive mode, the switch K 1  is connected to a lower contact, the switch K 2  is disconnected, and the switch K 3  is disconnected. In this case, electric energy that is output from the battery  501  is output to the motor winding  503  through the three-phase bridge arm converter  502 , to drive a motor. 
     In this embodiment of this application, when a left winding and a middle winding of the motor winding  503  are in the alternating current charging mode, a function of an energy storage inductor (which may also be referred to as a power factor correction (PFC) inductor) can be implemented. In the motor drive mode, a winding of the motor winding  503  is used as a winding for driving a motor according to a conventional solution. Therefore, in this embodiment of this application, not only the bridge arm of the three-phase bridge arm converter  502  is reused, but also the winding of the motor winding  503  is reused. This further increases an integration level and reduces a volume of the energy conversion apparatus. 
       FIG. 6  is a schematic diagram of another energy conversion apparatus according to an embodiment of this application. The energy conversion apparatus includes a battery  601 , a three-phase bridge arm converter  602 , a bridge arm circuit  603 , a motor winding  604 , a transformer  605 , and an alternating current charging port  606 . The battery  601  is similar to the battery  101  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. A connection between the three-phase bridge arm converter  602  and the motor winding  604  is similar to the connection between the three-phase bridge arm converter  102  and the motor winding  104  in the foregoing embodiments corresponding to  FIG. 1 . Details are not described herein again. 
     In this embodiment of this application, a direct current port of the bridge arm circuit  603  is connected to the battery  601 , and an alternating current port of the bridge arm circuit  603  is connected to a secondary-side winding of the transformer  605 . Specifically, one end of the secondary-side winding of the transformer  605  is connected to a busbar end of the motor winding  604  through a switch K 2 , and the other end of the secondary-side winding of the transformer  605  is connected to the alternating current port of the bridge arm circuit  603 . 
     It may be understood that the bridge arm circuit  603  may include switching transistors, diodes, or capacitors that are connected in series. This is not limited in this embodiment of this application. 
     In this embodiment of this application, the alternating current charging port  606  may further be specifically connected to a primary-side winding of the transformer  504  through an alternating current filter  506  and a flip-flop K 3 . The alternating current filter  506  and the switch K 3  are similar to the alternating current filter  107  and the switch  108  in the foregoing embodiments corresponding to  FIG. 1 , and details are not described herein again. 
     In this embodiment of this application, the switch K 2  and the switch K 3  each may be a flip-flop, a relay, or the like. This is not limited in this embodiment of this application. 
     When the energy conversion apparatus shown in  FIG. 6  runs in an alternating current charging mode, the switch K 2  and the switch K 3  are closed. Alternating current power that is input from the alternating current charging port  606  is transformed (voltage-up or voltage-down) by using the transformer  605  and then rectified into direct current power by using three bridge arms of the three-phase bridge arm converter  602  and the bridge arm circuit  603 , and the direct current power is delivered to the battery  601 , to charge the battery  601 . In this case, when the alternating current charging port  606  is not connected to a charging pile but connected to an electric device, electric energy in the battery  601  may be converted into an alternating current by using the three-phase bridge arm converter  602  and the bridge arm circuit  603 , to charge/supply power to the device connected to the alternating current charging port  606 . 
     When the energy conversion apparatus shown in  FIG. 6  runs in a motor drive mode, the switch K 2  and the switch K 3  are disconnected. Direct current power that is output from the battery  601  is delivered to the motor winding  604  through the three-phase bridge arm converter  602 , to drive a motor. 
     It may be understood that, when the energy conversion apparatus is in the alternating current charging mode, the energy conversion apparatus reuses the bridge arm of the three-phase bridge arm converter  602  and the winding of the motor winding  604 . This increases an integration level and reduces a volume of the energy conversion apparatus. 
     An embodiment of this application further provides a motor. The motor includes a housing, and the energy conversion apparatus shown in  FIG. 1 ,  FIG. 3 a   ,  FIG. 3 b   ,  FIG. 4 a   ,  FIG. 4 b   ,  FIG. 4 c   ,  FIG. 5 , or  FIG. 6  is accommodated in the housing. 
     An embodiment of this application further provides a power system, including a motor and the energy conversion apparatus shown in  FIG. 1 ,  FIG. 3 a   ,  FIG. 3 b   ,  FIG. 4 a   ,  FIG. 4 b   ,  FIG. 4 c   ,  FIG. 5 , or  FIG. 6 . A motor winding of the energy conversion apparatus is configured to drive the motor. 
     An embodiment of this application further provides a vehicle, including the energy conversion apparatus shown in  FIG. 1 ,  FIG. 3 a   ,  FIG. 3 b   ,  FIG. 4 a   ,  FIG. 4 b   ,  FIG. 4 c   ,  FIG. 5 , or  FIG. 6 , or including the foregoing power system. 
     It may be clearly understood by a person skilled in the art that, for purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments, and details are not described herein again. 
     In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, division into the units is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms. 
     The foregoing embodiments are merely intended for describing the technical solutions of this application, but not for limiting this application. Although this application is described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that modifications to the technical solutions recorded in the foregoing embodiments or equivalent replacements to some technical features thereof may still be made, without departing from the scope of the technical solutions of embodiments of this application.