Energy conversion system for a traction battery and vehicle

Abstract

An energy conversion system according to one aspect includes a power factor correction module including a first motor and a first inverter; a direct current conversion module coupled with the power factor correction module and including a second motor and a second inverter; a first switch module including a first switch unit coupled between an alternating current input and the power factor correction module and a second switch unit coupled between the direct current conversion module and a vehicle power battery; a second switch module including a third switch unit coupled between a direct current input and the power factor correction module and a fourth switch unit coupled between the power factor correction module and the direct current conversion module; and a control module configured to control the first switch module to close and the second switch module to open in a first charging mode to form a first charging loop and to control the first switch module to open and the second switch module to close in a second charging mode to form a second charging loop.

Description

Technical Field

[0001] This application generally relates to electric vehicle technology, and more specifically to an energy conversion system and vehicle for a power battery. Background Technology

[0002] With the increasing popularity of electric vehicles, the demand for charging them is growing. Currently, electric vehicle charging mainly includes AC charging and DC charging. AC charging utilizes the AC power provided by the external power grid, and the onboard charger (OBC) converts the AC power from the grid into DC power suitable for the electric vehicle's battery to charge it. DC charging uses the DC power directly output by the charging station to charge the battery.

[0003] An OBC typically includes an AC electromagnetic interference (EMI) filter module for filtering EMI on the AC power line, a power factor correction module for bidirectional conversion between the AC voltage of the power grid and the DC voltage of the power battery, an isolated DC-DC converter module for converting the DC output from the power factor correction module into DC suitable for charging the power battery and providing electrical isolation, and a control circuit module. However, to ensure the reliability and safety of charging and discharging, current OBCs usually require complex circuit designs and additional costs. For example, multiple modules mentioned above need to be installed in the vehicle, and these modules need to be electrically connected to external devices via high and low voltage wiring harnesses and connectors. This increases the overall size, weight, and production cost of the vehicle, and may also lead to serious electromagnetic interference problems. Summary of the Invention

[0004] To address or at least alleviate one or more of the above problems, the following technical solutions are provided.

[0005] According to a first aspect of this application, an energy conversion system for a power battery is provided, the energy conversion system comprising: a power factor correction module including a first motor and a first inverter; a DC-DC conversion module coupled to the power factor correction module and including a second motor and a second inverter, wherein the second motor includes a first winding and a second winding symmetrically wound in parallel; a first switching module including a first switching unit coupled between an AC input terminal and the power factor correction module and a second switching unit coupled between the DC-DC conversion module and the vehicle power battery; and a second switching module including a third switching unit coupled between a DC input terminal and the power factor correction module. The module includes a fourth switching unit coupled between the power factor correction module and the DC-DC conversion module; and a control module configured to: control the first switching module to close and control the second switching module to open in a first charging mode to form a first charging circuit between the AC input terminal and the vehicle power battery via the AC input terminal, the power factor correction module, and the DC-DC conversion module; and control the first switching module to open and control the second switching module to close in a second charging mode to form a second charging circuit between the DC input terminal and the vehicle power battery via the DC input terminal, the first motor, and the first inverter.

[0006] According to an embodiment of the energy conversion system of this application, the control module is further configured to: control the third switch unit in the first switch module and the second switch module to open and control the fourth switch unit in the second switch module to close in a discharge mode, so as to form a discharge circuit between the vehicle power battery and the first motor and the first inverter, and between the vehicle power battery and the second motor and the second inverter.

[0007] According to an embodiment of this application or any of the above embodiments, the energy conversion system wherein the first charging circuit is a non-boost charging circuit and the second charging circuit is a boost charging circuit, wherein the first motor and the second motor are respectively one of the following: a drive motor, a generator motor, an air compressor motor, a steering motor, a suspension motor, and a hub motor.

[0008] According to an embodiment of this application or any of the above embodiments, the energy conversion system further includes a cooling module, the cooling module including a first cooling channel and a second cooling channel, the refrigerant in the first cooling channel flows through the second motor, and the coolant in the second cooling channel flows through the second motor, the second inverter, the first inverter and the first motor.

[0009] According to an embodiment of the present application or any of the above embodiments of the energy conversion system, the DC conversion module further includes a half-bridge output module, the half-bridge output module includes a first half-bridge output arm and a second half-bridge output arm, and the power factor correction module further includes a half-bridge input arm.

[0010] According to an embodiment of the present application or any of the above embodiments of the energy conversion system, wherein the first inverter includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm, the second inverter includes a fourth phase bridge arm, a fifth phase bridge arm and a sixth phase bridge arm, wherein each phase winding of the first three-phase winding is respectively coupled to the fourth phase bridge arm, the fifth phase bridge arm and the sixth phase bridge arm of the second inverter, and two phase windings of the second three-phase winding are respectively coupled to the first half-bridge output bridge arm and the second half-bridge output bridge arm.

[0011] According to an embodiment of this application or any of the above embodiments, in the first charging mode, the control module is configured to: control the upper and lower bridge arm switches in the half-bridge input bridge arm to be complementaryly turned on; control the upper and lower bridge arm switches in each of the first, second, and third phase bridge arms in the first inverter to be complementaryly turned on; control the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms in the second inverter to be complementaryly turned on; and control the upper and lower bridge arm switches in each of the first and second half-bridge output bridge arms in the half-bridge output module to be complementaryly turned on.

[0012] According to an embodiment of this application or any of the above embodiments, in the second charging mode, the control module is configured to: control the upper bridge arm switch and the lower bridge arm switch in each of the first phase bridge arm, the second phase bridge arm and the third phase bridge arm in the first inverter to be complementaryly turned on.

[0013] According to an embodiment of this application or any of the above embodiments, in the discharge mode, the control module is configured to: control the upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter to conduct complementaryly; and control the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter to conduct complementaryly.

[0014] According to a second aspect of this application, a vehicle is provided, the vehicle comprising: a battery; and an energy conversion system according to a first aspect of this application.

[0015] The energy conversion system for power batteries according to one or more embodiments of this application can reuse existing power devices and electromechanical coupling components in electric vehicles to implement the OBC function, eliminating the need for additional independent components and wiring harnesses dedicated to the OBC function inside the vehicle. For example, it eliminates the need for an additional independent component for isolation transformers and additional wiring harnesses connecting independent power factor correction inductors inside the vehicle, thereby optimizing the design and layout of the electric vehicle charging system, reducing the overall vehicle size, weight, and production costs, and reducing electromagnetic interference between high-voltage components in the vehicle by reducing the use of high- and low-voltage wiring harnesses. The energy conversion system for power batteries according to one or more embodiments of this application has advantages such as cost savings, simple control, and ease of implementation. Attached Figure Description

[0016] The above and / or other aspects and advantages of this application will become clearer and more readily understood from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are denoted by the same reference numerals. In the drawings:

[0017] Figure 1 A structural block diagram of an energy conversion system for a power battery according to one or more embodiments of this application is shown.

[0018] Figure 2 A circuit diagram of an energy conversion system for a power battery according to one or more embodiments of this application is shown. Detailed Implementation

[0019] The following describes exemplary embodiments of this application in detail, and examples of these embodiments are illustrated in the accompanying drawings. It should be noted that the following description is for explanation and illustration only and should not be construed as limiting the scope of this application. Without departing from the principles of this application, those skilled in the art can make electrical, mechanical, logical, and structural modifications to these embodiments according to actual needs, without departing from the scope of this application. Furthermore, those skilled in the art will understand that one or more features of the different embodiments described below can be combined for any specific application scenario or actual need.

[0020] Terms such as "comprising" and "including" indicate that, in addition to the units and steps that are directly and explicitly described in the specification, the technical solution of this application does not exclude the presence of other units and steps that are not directly or explicitly described. Terms such as "first" and "second" do not indicate the order of the units in terms of time, space, size, etc., but are merely used to distinguish the units.

[0021] In the following description, numerous specific details, such as examples of specific components, circuits, and processes, are set forth to provide a thorough understanding of this application. As used herein, the term "coupling" means a direct connection to or a connection via one or more intermediate components or circuits. Furthermore, specific nomenclature is set forth in the following description and for illustrative purposes to provide a thorough understanding of various aspects of this application. However, it will be apparent to those skilled in the art that these specific details can be used to practice the exemplary implementations without requiring them.

[0022] Figure 1 A structural block diagram of an energy conversion system for a power battery according to one or more embodiments of this application is shown.

[0023] like Figure 1 As shown, the energy conversion system 100 for a power battery includes a power factor correction module 110, a DC-DC conversion module 120 coupled to the power factor correction module 110, a first switching module, a second switching module, and a control module 130, wherein the power factor correction module 110 includes a first motor and a first inverter ( Figure 1 (Not shown in the image), the DC-DC conversion module 120 includes a second motor and a second inverter (…). Figure 1 (Not shown in the image), the second motor includes a first winding and a second winding symmetrically wound to establish electrical isolation between the AC input terminal AC and the vehicle power battery 140. The first switching module includes first switching units K1 and K2 coupled between the AC input terminal AC and the power factor correction module 110, and second switching units K3 and K4 coupled between the DC conversion module 120 and the vehicle power battery 140. The second switching module includes third switching units K7 and K8 coupled between the DC input terminal DC and the power factor correction module 110, and fourth switching units K5 and K6 coupled between the power factor correction module 110 and the DC conversion module 120.

[0024] The control module 130 is configured to, in a first charging mode, control the closing of switch units K1, K2, K3, and K4 in the first switch module and control the opening of switch units K5, K6, K7, and K8 in the second switch module, so as to form a first charging circuit between the AC input terminal AC and the vehicle power battery 140 via the AC input terminal AC, the power factor correction module 110, and the DC conversion module 120; and in a second charging mode, control the opening of switch units K1, K2, K3, and K4 in the first switch module and control the closing of switch units K5, K6, K7, and K8 in the second switch module, so as to form a second charging circuit between the DC input terminal DC, the first motor in the power factor correction module 110, and the first inverter in the DC input terminal DC and the vehicle power battery 140.

[0025] In one embodiment, the AC input terminal can be connected to an AC charging power source, such as an AC charging pile, and the DC input terminal can be connected to a DC charging power source, such as a DC charging pile. In another embodiment, the first charging circuit is a non-boost charging circuit to achieve AC charging, and the second charging circuit is a boost charging circuit to achieve DC charging, thereby jointly covering the full-scenario charging needs of electric vehicles.

[0026] In one embodiment, in the first charging mode, the three-phase windings of the first motor in the power factor correction module 110 operate as power factor correction (PFC) inductors, and the three-phase bridge arms of the first inverter in the power factor correction module 110 operate as PFC fast transistors. This, combined with the three-phase windings of the first motor, enables three-phase interleaved control, allowing the current in the three-phase windings of the first motor to track the AC voltage waveform, thereby raising the power factor to, for example, 0.95 or higher. Under three-phase interleaved control, the upper and lower bridge arm switches in the three-phase bridge arms of the first inverter are complementaryly turned on, converting the AC input current at the AC input terminal into DC current. The DC-DC conversion module 120 can be configured to invert the DC output from the power factor correction module 110 into high-frequency AC, coupled through a transformer, and then rectified to provide the DC power required for charging the vehicle's power battery 140, while simultaneously providing electrical isolation between the grid side and the battery side.

[0027] In one embodiment, in the second charging mode, the three-phase winding of the first motor in the power factor correction module 110 can be reused as an energy storage inductor, and the first inverter in the power factor correction module 110 can be reused as a three-phase interleaved Boost circuit. For example, when the lower bridge arm switch of the first inverter is turned on and the upper bridge arm switch is turned off, the input current of the DC input terminal flows through the three-phase winding of the first motor to store energy. When the lower bridge arm switch of the first inverter is turned off and the upper bridge arm switch is turned on, the three-phase winding of the first motor releases energy, which is superimposed with the input voltage of the DC input terminal and then boosted to charge the vehicle power battery 140 through the turned-on upper bridge arm switch.

[0028] In one embodiment, the control module 130 can be configured to control K1, K2, K3, K4 in the first switch module and K7, K8 in the second switch module to open and control K5, K6 in the second switch module to close in the discharge mode, so as to form a discharge circuit between the vehicle power battery 140 and the first motor and the first inverter, and between the vehicle power battery 140 and the second motor and the second inverter. The first inverter can convert the DC power output from the vehicle power battery 140 into three-phase AC power to drive the first motor, and the second inverter can convert the DC power output from the vehicle power battery 140 into three-phase AC power to drive the second motor.

[0029] In one embodiment, the control module 130 may include a first motor controller for the first motor, a second motor controller for the second motor, and a vehicle controller. The vehicle controller can determine whether to enter the first charging mode, the second charging mode, or the discharging mode based on user operations (e.g., inserting a charging gun, shifting gears and driving) or sensor signals. It then controls the switching units K1, K2, K3, and K4 in the first switching module and the switching units K5, K6, K7, and K8 in the second switching module. The vehicle controller also sends control commands to the first motor controller and the second motor controller, so that the first motor controller and the second motor controller control the switching transistors in each phase arm of the first inverter and the second inverter, respectively.

[0030] In one embodiment, the first motor and the second motor can be one of the following: a drive motor, a generator motor, an air compressor motor, a steering motor, a suspension motor, a hub motor, or other high-voltage motors mounted on the high-voltage busbar.

[0031] In one embodiment, the energy conversion system 100 may further include a cooling module. Figure 1 (Not shown in the image) The cooling module may include a first cooling channel and a second cooling channel. The refrigerant in the first cooling channel flows through the second motor in the DC-DC converter module 120, and the coolant in the second cooling channel flows through the second motor and the second inverter in the DC-DC converter module 120, as well as the first inverter and the first motor in the power factor correction module 110. By setting the first cooling channel and the second cooling channel in the cooling module, the coolant can be cooled by the refrigerant, thereby reducing the temperature of the coolant entering the motor windings during charging and increasing the charging power.

[0032] It should be noted that, Figure 1 The power factor correction module 110, DC-DC conversion module 120, and control module 130 shown are all existing devices or components in the vehicle. The energy conversion system for power batteries according to one or more embodiments of this application reuses the three-phase windings of the first motor as the PFC inductor in AC charging mode, reuses the three-phase bridge arm operation of the first inverter to perform three-phase interleaved control with the three-phase windings of the first motor, and reuses the second motor to realize the isolation transformer function. Thus, the OBC function is realized in AC charging mode. There is no need to set up separate components (e.g., OBC independent PFC inductor, rectifier bridge, isolation transformer and dedicated inverter) and wiring harnesses (e.g., independent high-voltage wiring harness between OBC and battery, independent low-voltage control wiring harness of OBC) in the vehicle. This optimizes the design and layout of the electric vehicle charging system, reduces the overall vehicle size, weight and production cost, and reduces the electromagnetic interference between high-voltage components in the vehicle by reducing the use of high and low voltage wiring harnesses.

[0033] The following will combine Figure 2 The circuit structure and working principle of an energy conversion system for a power battery according to one or more embodiments of this application are described in detail.

[0034] like Figure 2 As shown, the energy conversion system 200 for a power battery includes a power factor correction module 210, a DC-DC conversion module 220 coupled to the power factor correction module 210, a first switching module, a second switching module, and a control module. Figure 2 (Not shown in the image), wherein the power factor correction module 210 includes a first motor 2101, a first inverter 2102 and a half-bridge input arm 2103, the DC-DC conversion module 220 includes a second motor 2201, a second inverter 2202 and a half-bridge output module 2203, the first switching module includes first switching units K1 and K2 coupled between the AC input terminals AC1 and AC2 and the power factor correction module 210 and second switching units K3 and K4 coupled between the DC-DC conversion module 220 and the vehicle power battery 240, the second switching module includes third switching units K7 and K8 coupled between the DC input terminals DC+ and DC- and the power factor correction module 210 and fourth switching units K5 and K6 coupled between the power factor correction module 210 and the DC-DC conversion module 220.

[0035] Continue as Figure 2As shown, the first inverter 2102 includes a first phase bridge arm, a second phase bridge arm, and a third phase bridge arm. The first phase bridge arm includes switches Q1 and Q2, the second phase bridge arm includes switches Q3 and Q4, and the third phase bridge arm includes switches Q5 and Q6. The half-bridge input bridge arm 2103 includes switches Q7 and Q8. The first phase bridge arm, the second phase bridge arm, and the third phase bridge arm of the first inverter 2102 are respectively connected to the three-phase windings of the first motor 2101, namely U, V, and W. The neutral point of the three-phase windings of the first motor 2101 is connected to the AC input terminal AC1 through the first switching unit K1 and to the DC input terminal DC+ through the third switching unit K7. The AC input terminal AC2 is connected to the half-bridge input bridge arm 2103 through the first switching unit K2, and the DC input terminal DC- is connected to the first inverter 2102 through the third switching unit K8. The second motor 2201 includes symmetrical first three-phase windings A, B, C and second three-phase windings a, b, c for establishing electrical isolation between the AC input terminals AC1, AC2 and the vehicle power battery 240. The second inverter 2202 includes a fourth phase bridge arm, a fifth phase bridge arm and a sixth phase bridge arm, wherein the fourth phase bridge arm includes switching transistors Q9 and Q10, the fifth phase bridge arm includes switching transistors Q11 and Q12, and the sixth phase bridge arm includes switching transistors Q13 and Q14, wherein the fourth phase bridge arm, the fifth phase bridge arm and the sixth phase bridge arm are respectively connected to the first three-phase windings A, B, and C of the second motor 2201. The half-bridge output module 2203 includes a first half-bridge output arm and a second half-bridge output arm. The first half-bridge output arm includes switching transistors Q15 and Q16, and the second half-bridge output arm includes switching transistors Q17 and Q18. The first half-bridge output arm and the second half-bridge output arm are respectively connected to any two windings (e.g., a, b, c) of the second three-phase windings of the second motor 2201. Figure 2 The windings b and c are shown in the diagram.

[0036] It should be noted that, although Figure 2 The power switching devices Q1-Q18 are shown as metal-oxide-semiconductor field-effect transistors (MOSFETs). However, without departing from the spirit and scope of this application, the power switching devices Q1-Q18 can also be implemented as one or more of various types of switching transistors such as bipolar junction transistors (BJTs) and insulated-gate bipolar transistors (IGBTs).

[0037] In one embodiment, the AC input terminals AC1, AC2 and the DC input terminals DC+, DC- can be charging piles, charging stations, or other voltage sources capable of charging vehicles. In one embodiment, the first motor 2101 and the second motor 2201 can be implemented as one of the following: a front or rear drive motor, a generator motor, an air compressor motor, a steering motor, a suspension motor, a hub motor, or other high-voltage motor mounted on a high-voltage bus. The following describes in further detail the use of... Figure 2 The energy conversion system 200 for power batteries shown implements a first charging mode, a second charging mode, and a discharging mode.

[0038] In the first charging mode, the control module controls the closing of switch units K1, K2, K3, and K4 in the first switch module and controls the opening of switch units K5, K6, K7, and K8 in the second switch module, so as to form an AC charging circuit between the AC input terminals AC1 and AC2 and the vehicle power battery 240 via the AC input terminals AC1 and AC2, the power factor correction module 210, and the DC conversion module 220.

[0039] Optionally, in the first charging mode, the control module can control the upper arm switch Q7 and the lower arm switch Q8 in the half-bridge input arm 2103 to conduct complementaryly. For example, the switch Q7 can be turned on and the switch Q8 can be turned off according to the frequency of the AC grid, or the switch Q8 can be turned on and the switch Q7 can be turned off. The upper arm switch and the lower arm switch in each of the first phase arm, the second phase arm and the third phase arm in the first inverter 2102 can be controlled to conduct complementaryly. The upper arm switch and the lower arm switch in each of the fourth phase arm, the fifth phase arm and the sixth phase arm in the second inverter 2202 can be controlled to conduct complementaryly. The upper arm switch and the lower arm switch in each of the first half-bridge output arm and the second half-bridge output arm in the half-bridge output module 2203 can be controlled to conduct complementaryly. By reusing the three-phase windings of the first motor 2101 as PFC inductors, the half-bridge input arm 2103 as a slow PFC transistor, and the three-phase arm of the first inverter 2102 as a fast PFC transistor, three-phase interleaving control is achieved in conjunction with the three-phase windings of the first motor 2101 to convert the AC current input at AC1 and AC2 into DC current. The second motor 2201 is reused to implement the isolation transformer function by using any two windings from the second three-phase windings a, b, and c (e.g., ...). Figure 2 The windings b and c shown are connected to the first half-bridge output arm and the second half-bridge output arm respectively to realize the function of isolated bidirectional active bridge, which inverts the DC power output of the power factor correction module 210 into high-frequency AC power, and then rectifies it after being coupled by the transformer to provide the DC power required for charging the vehicle power battery 240, while providing electrical isolation between the grid side and the battery side.

[0040] In one embodiment, in the first charging mode, the control module can control the switches Q1 and Q2 in the first phase arm of the first inverter 2102 to conduct complementaryly, that is, when switch Q1 is on, switch Q2 is off, and vice versa. Similarly, the control module can control the switches Q3 and Q4 in the second phase arm and Q5 and Q6 in the third phase arm of the first inverter 2102 to conduct complementaryly, that is, when switch Q3 is on, switch Q4 is off, and vice versa; when switch Q5 is on, switch Q6 is off, and vice versa. In one embodiment, the control signals between the first, second, and third phase arms of the first inverter 2102 can have a 120° phase difference, thereby achieving three-phase interleaved control to effectively reduce current ripple and improve the power factor correction effect.

[0041] In one embodiment, in the first charging mode, the control module can control the upper arm switch Q7 and the lower arm switch Q8 in the half-bridge input arm 2103 to conduct complementaryly. For example, during the positive half-cycle of the AC voltage, switch Q7 is turned on and switch Q8 is turned off; during the negative half-cycle of the AC voltage, switch Q8 is turned on and switch Q7 is turned off.

[0042] In one embodiment, in the first charging mode, the control module can control the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter 2202 to conduct complementaryly. For example, when switch Q9 is on, switch Q10 is off, and vice versa, thereby inverting the DC power output from the power factor correction module 210 into high-frequency AC power, driving the first three-phase windings A, B, and C of the second motor 2201 to generate an alternating magnetic field, and then generating induced AC current in the second three-phase windings a, b, and c of the second motor 2201.

[0043] In one embodiment, in the first charging mode, the control module can control the upper and lower arm switches in each of the first and second half-bridge output arms of the half-bridge output module 2203 to conduct complementaryly, for example, controlling switches Q15 and Q17 to conduct and Q16 and Q18 to turn off, thereby rectifying the induced AC current generated in the second three-phase windings a, b, and c of the second motor 2201 into DC current, and realizing the charging of the vehicle power battery 240.

[0044] In one embodiment, in the first charging mode, capacitor C1 can be used to filter out the high-frequency voltage ripple generated by the high-frequency switching of the PFC fast transistors (switching transistors Q1-Q6), and capacitor C2 can be used to filter out the ripple in the DC current output by the half-bridge output module 2203, thereby ensuring that the input current of the vehicle power battery 240 is smoother, which is beneficial to the battery charging process and extends the battery's service life.

[0045] In the second charging mode, the control module controls the switch units K1, K2, K3, and K4 in the first switch module to open and controls the switch units K5, K6, K7, and K8 in the second switch module to close, so as to form a DC charging circuit between the DC input terminals DC+ and DC- and the vehicle power battery 240 via the DC input terminals DC+ and DC-, the first motor 2101, and the first inverter 2102.

[0046] Optionally, in the second charging mode, the control module can control the upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter 2102 to conduct complementaryly.

[0047] In one embodiment, in the second charging mode, the winding of the first motor 2101 in the power factor correction module 210 can be reused as an energy storage inductor, and the first inverter 2102 in the power factor correction module 210 can be reused as a three-phase interleaved Boost circuit. For example, when the switch Q1 in the first phase bridge arm of the first inverter 2102 is off and the switch Q2 is on, the DC input voltage stores energy in the U-phase winding of the first motor 2101; when the switch Q1 in the first phase bridge arm of the first inverter 2102 is on and the switch Q2 is off, the U-phase winding of the first motor 2101 releases energy, which, after being superimposed with the DC input voltage, is used to boost charge the vehicle's power battery 240 via the on-state switch Q1 and the switching units K5 and K6 in the second switching module. For example, when the switch Q3 in the second phase bridge arm of the first inverter 2102 is turned off and the switch Q4 is turned on, the DC input voltage stores energy in the V phase winding of the first motor 2101; when the switch Q3 in the second phase bridge arm of the first inverter 2102 is turned on and the switch Q4 is turned off, the V phase winding of the first motor 2101 releases energy, which, after being superimposed with the DC input voltage, is used to boost and charge the vehicle power battery 240 through the turned-on switch Q3 and the switch units K5 and K6 in the second switch module. For example, when the switch Q5 in the third phase bridge arm of the first inverter 2102 is turned off and the switch Q6 is turned on, the DC input voltage stores energy in the W phase winding of the first motor 2101; when the switch Q5 in the third phase bridge arm of the first inverter 2102 is turned on and the switch Q6 is turned off, the W phase winding of the first motor 2101 releases energy, which, after being superimposed with the DC input voltage, is used to boost and charge the vehicle power battery 240 through the turned-on switch Q5 and the switch units K5 and K6 in the second switch module.

[0048] In one embodiment, in the second charging mode, capacitor C1 can be used to filter out the high-frequency voltage ripple generated by the high-frequency switching of switching transistors Q1-Q6, and capacitor C3 can be used to filter out the high-frequency voltage ripple of the boosted DC voltage.

[0049] In the discharge mode, the control module controls the switching units K1, K2, K3, K4 in the first switching module and the switching units K7, K8 in the second switching module to open and control the switching units K5, K6 in the second switching module to close, so as to form a discharge circuit between the vehicle power battery 240 and the first motor 2101 and the first inverter 2102, and between the vehicle power battery 240 and the second motor 2201 and the second inverter 2202. The first inverter 2102 can invert the DC power output from the vehicle power battery 240 into three-phase AC power to drive the first motor 2101 to operate, and the second inverter 2202 can invert the DC power output from the vehicle power battery 240 into three-phase AC power to drive the second motor 2201 to operate.

[0050] Optionally, in discharge mode, the control module can control the upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter 2102 to conduct complementaryly, and control the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter 2202 to conduct complementaryly.

[0051] In one embodiment, the control module can generate a three-phase pulse width modulation signal using a space vector pulse width modulation algorithm based on the target speed and torque of the first motor 2101 to control the on / off state of the upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter 2102. In another embodiment, the control module can generate a three-phase pulse width modulation signal using a space vector pulse width modulation algorithm based on the target speed and torque of the second motor 2201 to control the on / off state of the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter 2202.

[0052] In one embodiment, the energy conversion system 200 may include a cooling module, which may include a first cooling channel 2301 and a second cooling channel 2302. The refrigerant in the first cooling channel 2301 flows through the second motor 2201, and the coolant in the second cooling channel 2302 flows through the second motor 2201, the second inverter 2202, the first inverter 2102, and the first motor 2101. By providing the first and second cooling channels in the cooling module, the coolant can be cooled by the refrigerant, thereby reducing the temperature of the coolant entering the motor windings during charging and increasing the charging power.

[0053] In one embodiment, the energy conversion system 200 may further include multiple electromagnetic compatibility filters, which may be respectively disposed between the switching units K1, K2 and the power factor correction module 210, between the switching units K7, K8 and the power factor correction module 210, between the switching units K3, K4 and the DC-DC conversion module 220, and between the power factor correction module 210 and the DC-DC conversion module 220. The multiple electromagnetic compatibility filters work together in different locations to suppress electromagnetic interference from input to output in all directions, ensuring the stable operation of electric vehicle charging and discharging.

[0054] Alternatively, this application can also be implemented as a vehicle that includes an energy conversion system for a power battery according to one aspect of this application.

[0055] The embodiments and examples presented herein are provided to best illustrate embodiments of this application and its particular applications, thereby enabling those skilled in the art to implement and use this application. However, those skilled in the art will understand that the above description and examples are provided for ease of illustration and example only. The descriptions presented are not intended to cover all aspects of this application or to limit this application to the precise forms disclosed.

Claims

1. An energy conversion system for a power battery, characterized in that, The energy conversion system includes: A power factor correction module, comprising a first motor and a first inverter; A DC-DC conversion module coupled to the power factor correction module and including a second motor and a second inverter, wherein the second motor includes a first winding and a second winding symmetrically wound in parallel; The first switching module includes a first switching unit coupled between the AC input terminal and the power factor correction module, and a second switching unit coupled between the DC conversion module and the vehicle power battery. The second switching module includes a third switching unit coupled between the DC input terminal and the power factor correction module, and a fourth switching unit coupled between the power factor correction module and the DC-DC conversion module; and The control module is configured as follows: In the first charging mode, the first switch module is controlled to close and the second switch module is controlled to open, so as to form a first charging circuit between the AC input terminal and the vehicle power battery via the AC input terminal, the power factor correction module, and the DC conversion module; and In the second charging mode, the first switch module is controlled to open and the second switch module is controlled to close, so as to form a second charging circuit between the DC input terminal and the vehicle power battery via the DC input terminal, the first motor and the first inverter.

2. The energy conversion system according to claim 1, wherein the control module is further configured to: In discharge mode, the third switch unit in the first switch module and the second switch module are controlled to open and the fourth switch unit in the second switch module is controlled to close, so as to form a discharge circuit between the vehicle power battery and the first motor and the first inverter, and between the vehicle power battery and the second motor and the second inverter.

3. The energy conversion system according to claim 1, wherein the first charging circuit is a non-boost charging circuit, the second charging circuit is a boost charging circuit, and wherein the first motor and the second motor are respectively one of the following: a drive motor, a generator motor, an air compressor motor, a steering motor, a suspension motor, and a hub motor.

4. The energy conversion system according to claim 1, wherein the energy conversion system further includes a cooling module, the cooling module including a first cooling channel and a second cooling channel, wherein the refrigerant in the first cooling channel flows through the second motor, and the coolant in the second cooling channel flows through the second motor, the second inverter, the first inverter and the first motor.

5. The energy conversion system according to claim 1, wherein the DC conversion module further includes a half-bridge output module, the half-bridge output module includes a first half-bridge output arm and a second half-bridge output arm, wherein the power factor correction module further includes a half-bridge input arm.

6. The energy conversion system according to claim 5, wherein the first inverter includes a first phase bridge arm, a second phase bridge arm, and a third phase bridge arm, the second inverter includes a fourth phase bridge arm, a fifth phase bridge arm, and a sixth phase bridge arm, wherein each phase winding of the first three-phase winding is respectively coupled to the fourth phase bridge arm, the fifth phase bridge arm, and the sixth phase bridge arm of the second inverter, and two phase windings of the second three-phase winding are respectively coupled to the first half-bridge output bridge arm and the second half-bridge output bridge arm.

7. The energy conversion system according to claim 6, wherein in the first charging mode, the control module is configured to: The upper bridge arm switch and the lower bridge arm switch in the half-bridge input bridge arm are controlled to conduct complementaryly; The upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter are controlled to conduct in a complementary manner. Controlling the complementary conduction of the upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter; and The upper and lower bridge arm switches in each of the first and second half-bridge output arms of the half-bridge output module are complementaryly turned on.

8. The energy conversion system according to claim 6, wherein the control module is configured to: The upper and lower bridge arm switches in each of the first, second, and third phase bridge arms of the first inverter are controlled to conduct complementaryly.

9. The energy conversion system according to claim 2 or 6, wherein in the discharge mode the control module is configured to: Controlling the upper and lower bridge arm switches in each of the first, second, and third phase arms of the first inverter to conduct complementaryly; and The upper and lower bridge arm switches in each of the fourth, fifth, and sixth phase bridge arms of the second inverter are complementaryly turned on.

10. A vehicle comprising: The energy conversion system for a power battery according to any one of claims 1 to 9.

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