Energy conversion device and vehicle

Abstract

The present application relates to an energy conversion device and a vehicle, comprising: a motor control module, a motor winding, a low-frequency bridge module, a DC transformer module and a controller connected in sequence, the motor winding and the low-frequency bridge module are also connected to an AC charging interface, and the DC transformer module is also connected to a power battery; the controller is configured to: in a motor drive mode, control the motor winding, the motor control module, the DC transformer module and the power battery to form a motor drive circuit; in an AC charging mode, reuse the motor winding and the motor control module, and form an AC charging circuit by controlling the AC charging interface, the motor winding, the motor control module, the low-frequency bridge module, the DC transformer module and the power battery. Thus, the reuse of the motor control module and the motor winding realizes the function of AC charging, improves the integration, improves the power density of the device, and reduces the volume and cost.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular, to an energy conversion device and a vehicle. Background Art

[0002] With the development of new energy vehicles, users have higher and higher requirements for the functions of new energy vehicles, and enterprises are under increasing pressure to improve the technology of new energy vehicles and reduce costs. For example, the increasing number of electronic components with functional configurations in new energy vehicles has the most direct impact on both the vehicle functional configuration and the cost reduction of enterprises. In the application of electric vehicles, the layout of various vehicle functional configurations is dispersed and single in function, which makes the layout space of the whole vehicle larger and the circuit structure of the whole vehicle complex, that is, the integration is not high, which wastes the layout space of the whole vehicle and greatly increases the production cost. Summary of the invention

[0003] The purpose of this application is to provide an energy conversion device and a vehicle.

[0004] In order to achieve the above objectives, in a first aspect, the present application provides an energy conversion device, including: an energy conversion circuit, wherein the energy conversion circuit includes:

[0005] Motor control module;

[0006] A motor winding, wherein the neutral point of the motor winding is connected to the positive pole of the AC charging interface, and the other end of the motor winding is connected to the motor control module;

[0007] A low-frequency bridge module, wherein a first end of the low-frequency bridge module is connected to a first bus terminal of the motor control module, a second end of the low-frequency bridge module is connected to a second bus terminal of the motor control module, and a negative pole of the AC charging port is connected to a midpoint of the low-frequency bridge module;

[0008] A DC transformer module, wherein a first end of the DC transformer module is connected to a first end of the low-frequency bridge module, and a second end of the DC transformer module is connected to a second end of the low-frequency bridge module; a third end of the DC transformer module is connected to a positive electrode of a power battery, and a fourth end of the DC transformer module is connected to a negative electrode of the power battery;

[0009] A controller configured to: in a motor drive mode, control the motor winding, the motor control module, the DC transformer module and the power battery to form a motor drive circuit;

[0010] In the AC charging mode, the AC charging interface, the motor winding, the motor control module, the low-frequency bridge module, the DC transformer module and the power battery are controlled to form an AC charging circuit.

[0011] Furthermore, the device also includes:

[0012] A first switch module, wherein a first end of the first switch module is connected to the positive electrode of the AC charging interface, and a second end of the first switch module is connected to the positive electrode of the power battery;

[0013] a second switch module, wherein a first end of the second switch module is connected to a second bus terminal of the motor control module, and a second end of the second switch module is connected to a negative electrode of the power battery;

[0014] The controller is configured to: in a motor drive mode, control the first switch module and the second switch module to be disconnected, and control the motor winding, the motor control module, the DC transformer module and the power battery to form a motor drive circuit;

[0015] In the AC charging mode, the first switch module and the second switch module are controlled to be disconnected, and the AC charging interface, the motor winding, the motor control module, the low-frequency bridge module, the DC transformer module and the power battery are controlled to form an AC charging circuit;

[0016] In the battery self-heating mode, the first switch module and the second switch module are controlled to be turned on, and the motor control module, the motor winding, the first switch module, the second switch module, the DC transformer module and the battery form a battery self-heating circuit.

[0017] Further, the motor winding includes a multi-phase winding coil, one end of the multi-phase winding coil is connected in common to form a neutral point;

[0018] The motor control module includes a multi-phase high-frequency bridge arm, the first ends of the multi-phase high-frequency bridge arms are connected together to form a first bus terminal of the motor control module, the second ends of the multi-phase high-frequency bridge arms are connected together to form a second bus terminal of the motor control module, and the midpoint of each phase high-frequency bridge arm is connected to the other end of each phase winding coil; wherein the number of phases of the high-frequency bridge arm is equal to the number of phases of the winding coil.

[0019] Furthermore, the low-frequency bridge module includes at least one phase of low-frequency bridge arm, the first ends of all the low-frequency bridge arms form the first end of the low-frequency bridge module, the second ends of all the low-frequency bridge arms form the second end of the low-frequency bridge module, and the midpoints of all the low-frequency bridge arms are connected to the negative pole of the AC charging port.

[0020] Further, the DC transformer module includes: a first capacitor, an AC side power switch unit, a transformer unit, a battery side power switch unit and a second capacitor, wherein the transformer unit is connected to the AC side power switch unit and the battery side power switch unit respectively;

[0021] The first end of the first capacitor and the first end of the AC side power switch unit are connected together to form the first end of the DC transformer module, and the second end of the first capacitor and the second end of the AC side power switch unit are connected together to form the second end of the DC transformer module;

[0022] The first end of the second capacitor and the first end of the battery-side power switch unit are connected together to form the third end of the DC transformer module, and the second end of the first capacitor and the second end of the battery-side power switch unit are connected together to form the fourth end of the DC transformer module.

[0023] Furthermore, in the battery self-heating mode, the controller controls the motor control module so that the first capacitor of the DC transformer module and the power battery are cyclically charged and discharged according to a charge and discharge cycle, and the charge and discharge cycle includes: a discharge energy storage stage, a discharge energy release stage, a charge energy storage stage, and a charge energy release stage.

[0024] Furthermore, when the battery self-heating circuit is in the discharge energy storage stage, the battery, the first switch module, the motor winding, the lower bridge arm of the high-frequency bridge arm, and the second switch module form a discharge energy storage loop;

[0025] When the battery self-heating circuit is in the discharge energy release stage, the power battery, the first switch module, the motor winding, the upper bridge arm of the high-frequency bridge arm, the first capacitor, and the second switch module form a discharge energy release loop;

[0026] When the battery self-heating circuit is in the charging energy storage stage, the first capacitor, the upper bridge arm of the high-frequency bridge arm, the motor winding, the first switch module, the power battery, and the second switch module form a charging energy storage loop;

[0027] When the battery self-heating circuit is in the charging and energy release stage, the motor winding, the first switch module, the power battery, the second switch module, and the lower bridge arm of the high-frequency bridge arm form a charging and energy release loop.

[0028] Further, in the motor driving mode, when the multi-phase high-frequency bridge arm of the motor control module is controlled, the multi-phase high-frequency bridge arm is controlled to form a current vector so that the motor winding outputs torque.

[0029] Furthermore, in the AC charging mode, when the multi-phase high-frequency bridge arm of the motor control module is controlled, the upper bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, or the lower bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, and the motor winding has no torque output.

[0030] A second aspect of the present application provides a vehicle, comprising the energy conversion device described in the first aspect.

[0031] The technical solution of the present application provides an energy conversion device and a vehicle, which realizes deep integration of the motor drive circuit and the AC charging circuit by reusing the motor windings and the motor control module in the motor drive circuit as the filter inductor and power switching device of the AC charger, optimizes the topology of the two modules and integrates them, which can realize different working states, improve the integration level, reduce the use of power MOS, maximize the power density of the device, and reduce the volume and cost.

[0032] Other features and advantages of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0034] Figure 1 It is a structural block diagram of an energy conversion device according to an embodiment.

[0035] Figure 2 It is a structural block diagram of an energy conversion device according to an embodiment.

[0036] Figure 3 It is a schematic diagram of a working mode of an energy conversion device according to an embodiment.

[0037] Figure 4 is a schematic diagram of another working mode of an energy conversion device according to an embodiment.

[0038] Figure 5a-5d It is a schematic diagram of the working principle of a working mode of an energy conversion device according to an embodiment.

[0039] Figure 6 It is a schematic diagram of the structure of a vehicle according to an embodiment.

[0040] Reference numerals:

[0041] 1. AC charging interface; 2. Motor winding; 3. Motor control module; 4. Low-frequency bridge module;

[0042] 5. DC transformer module; 51. AC side power switch unit; 52. Transformer unit;

[0043] 53. Battery side power switch unit; C1. First capacitor; C2. Second capacitor;

[0044] 6. Power battery; 7. Controller; 8. First switch module; 9. Second switch module; 100 Energy conversion device. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] In order to illustrate the technical solution of this application, Figure 1-Figure 6 The following description will be given by way of specific examples.

[0047] Figure 1 FIG. 1 is a structural block diagram of an energy conversion device 100 according to an exemplary embodiment. Figure 1 As shown, the energy conversion device 100 includes a motor control module 3, a motor winding 2, a low-frequency bridge module 4 and a DC transformer module 5. The motor control module 3, the motor winding 2, the low-frequency bridge module 4 and the DC transformer module 5 are electrically connected in sequence, and the low-frequency bridge module 4 and the motor winding 2 are also electrically connected to the AC charging interface, and the DC transformer module 5 is also connected to the power battery 6.

[0048] Specifically, the neutral point of the motor winding 2 is connected to the positive pole of the AC charging interface, and the other end of the motor winding 2 is connected to the midpoint of the motor control module 3; the first end of the low-frequency bridge module 4 is connected to the first bus terminal of the motor control module 3, the second end of the low-frequency bridge module 4 is connected to the second bus terminal of the motor control module 3, and the negative pole of the AC charging port is connected to the midpoint of the low-frequency bridge module 4; the first end of the DC transformer module 5 is connected to the first end of the low-frequency bridge module 4, and the second end of the DC transformer module 5 is connected to the second end of the low-frequency bridge module 4; the third end of the DC transformer module 5 is connected to the positive pole of the power battery 6, and the fourth end of the DC transformer module 5 is connected to the negative pole of the power battery 6.

[0049] Furthermore, the energy conversion device also includes: a controller 7, which is configured to: in the AC charging mode, control the AC charging interface, the motor winding 2, the motor control module 3, the low-frequency bridge module 4, the DC transformer module 5 and the power battery 6 to form an AC charging circuit.

[0050] In the motor driving mode, the motor winding 2, the motor control module 3, the DC transformer module 5 and the power battery 6 are controlled to form a motor driving circuit.

[0051] like Figure 1As shown, the controller 7 is respectively connected to the motor control module 3, the low-frequency bridge module 4, and the DC transformer module 5. The controller 7 can also be selectively connected to the AC charging interface 1 and the power battery, which is not specifically shown in the figure.

[0052] For example, the controller 7 can reuse the battery manager, the vehicle controller 7 and other controllers 7. The AC charging mode can be automatically triggered and set after the vehicle is successfully connected to the external AC power supply device, or it can be set by the user after the vehicle is connected to the external AC power supply device. The motor drive mode can be automatically set according to the preset requirements of the vehicle, or it can be triggered and set by the vehicle according to the user's operation instructions.

[0053] In one embodiment, the energy conversion device also includes a first switch module 8 and a second switch module 9, the first switch module 8, the first end of the first switch module 8 is connected to the positive pole of the AC charging interface 1, and the second end of the first switch module 8 is connected to the positive pole of the power battery 6; the first end of the second switch module 9 is connected to the second bus terminal of the motor control module 3, and the second end of the second switch module 9 is connected to the negative pole of the power battery 6.

[0054] When the first switch module 8 and the second switch module 9 are disconnected, the AC charging interface 1, the motor winding 2, the motor control module 3, the low-frequency bridge module 4, the DC transformer module 5, the power battery 6 and the external power supply device form an AC charging circuit, and control the motor control module 3 and the low-frequency bridge module 4 so that the external power supply device charges the power battery 6. The AC charging interface 1 is used to connect an external power supply device. In addition, when the first switch module 8 and the second switch module 9 are disconnected, the motor winding 2, the motor control module 3, the DC transformer module 5 and the power battery 6 form a motor drive circuit, and control the motor control module so that the battery provides the required current to the motor winding 2, and the motor corresponding to the motor winding 2 is in a driving state.

[0055] When the first switch module 8 and the second switch module 9 are turned on, the motor control module 3, the motor winding 2, the first switch module 8, the second switch module 9, the DC transformer module 5 and the battery form a battery self-heating circuit. In the battery self-heating circuit, the battery is cyclically charged and discharged by controlling the motor control module 3 to achieve battery heating. During the battery charging and discharging process (e.g., cyclic charging and discharging), due to the existence of the battery internal resistance, the battery itself will generate a large amount of heat, causing the battery to heat up, thereby achieving battery heating.

[0056] In a specific embodiment, the motor control module 3 includes multi-phase high-frequency bridge arms connected in parallel, the first ends of all phase high-frequency bridge arms in the motor control module 3 are connected together to form a first loop end of the motor control module 3, and the second ends of all phase high-frequency bridge arms are connected together to form a second sink end of the motor control module 3. Each phase high-frequency bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm are connected in series, and the midpoint of the bridge arm is formed between the upper bridge arm and the lower bridge arm. For example, Figure 1 Take the motor control module 3 in the example including a three-phase high-frequency bridge arm, the midpoint of the motor control module 3 is point A, point B and point C. The upper bridge arm and the lower bridge arm of the high-frequency bridge arm each include a power switch unit, and the power switch unit can be a transistor, IGBT, MOS tube or other device types or a combination thereof. It can be understood that the number of phases of the high-frequency bridge arm of the motor control module 3 is the same as the number of phases of the corresponding motor. For example, if the motor is a three-phase motor, a five-phase motor, a six-phase motor, a nine-phase motor, a fifteen-phase motor, etc., then the number of phases corresponding to the high-frequency bridge arm of the motor controller 7 is three-phase, five-phase, six-phase, nine-phase, fifteen-phase, etc.

[0057] The motor winding 2 includes multi-phase winding coils connected in parallel, one end of each phase winding coil is connected together to form the neutral point of the motor winding 2, and the other end of each phase winding coil is connected one-to-one with the midpoint of each phase high-frequency bridge arm. The number of phases of the winding coil is the number of phases of the motor, and the number of phases of the winding coil is equal to the number of phases of the high-frequency bridge arm.

[0058] The low-frequency bridge module 4 includes at least one phase low-frequency bridge arm connected in parallel, the first ends of all phase low-frequency bridge arms in the low-frequency bridge module 4 are connected together to form the first end of the low-frequency bridge module 4, and the second ends of all phase low-frequency bridge arms are connected together to form the second end of the low-frequency bridge module 4. Each phase low-frequency bridge arm includes an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm are connected in series, and the midpoint of the bridge arm is formed between the upper bridge arm and the lower bridge arm. Figure 1 For example, the low-frequency bridge module 4 in the embodiment includes a single-phase low-frequency bridge arm, and the midpoint of the low-frequency bridge module 4 is point D. The upper bridge arm and the lower bridge arm of the low-frequency bridge arm each include a power switch unit, and the power switch unit can be a device type such as a transistor, an IGBT, a MOS tube, or a combination thereof. Among them, the switching frequency of the switch tube of the low-frequency bridge arm is relatively low, and the switching frequency of the switch tube of the high-frequency bridge arm is relatively high.

[0059] The DC transformer module 5 includes: a first capacitor C1, a battery-side power switch unit 53, a transformer 52 unit, an AC-side power switch unit 51 and a second capacitor C2;

[0060] The first end of the first capacitor C1 is connected with the first end of the AC side power switch unit 51 to form the first end of the DC transformation module 5, and the second end of the first capacitor C1 is connected with the second end of the AC side power switch unit 51 to form the second end of the DC transformation module 5; the first end of the second capacitor C2 is connected with the first end of the battery side power switch unit 53 to form the third end of the DC transformation module 5, and the second end of the first capacitor C1 is connected with the second end of the battery side power switch unit 53 to form the fourth end of the DC transformation module 5; the transformer 52 unit is connected to the AC side power switch unit 51 and the battery side power switch unit 53.

[0061] The DC transformer module 5 is used to convert the rectified and filtered DC power into a boost or a buck to charge the power battery 6. Specifically, the rectified and filtered DC power is stored in the first capacitor C1, converted into AC power by the AC side power switch unit 51, and boosted or bucked by the transformer 52 unit for power conversion, and the AC power after power change is converted into DC power by the battery side power switch unit 53 and stored in the second capacitor C2 to charge the power battery 6.

[0062] In the AC charging circuit, a DC transformer module 5 must be provided on the AC side and the power battery 6 side for AC / DC transformer isolation to ensure the high voltage safety of the battery. The DC transformer module 5 can be a bidirectional DC-DC converter to meet the voltage and current requirements of the load end. The bidirectional DC-DC converter can convert the grid voltage into a high voltage to charge the battery pack to meet the charging requirements, and can also convert the battery pack voltage into a rated output voltage to meet the power supply requirements.

[0063] In this embodiment, by reusing the motor winding 2 and motor control module 3 of the vehicle, the driving function, battery charging function and battery self-heating function can be realized respectively, without adding additional power distribution, further improving the utilization efficiency of the motor and improving the integration of the whole vehicle. In addition, there is no need to add battery heaters, heating pipes and other devices, which simplifies the structural design of the battery pack, and can also make the driving, charging and self-heating functions redundant, improving the reliability of the system.

[0064] Furthermore, the controller 77 controls the motor control module 3 so that the first capacitor C1 and the power battery 6 are charged and discharged once as a charge-discharge cycle. In the battery self-heating mode, the controller 7 controls the motor control module 3 so that the first capacitor C1 of the DC transformer module 5 and the power battery 6 are cyclically charged and discharged according to the charge-discharge cycle. Among them, a charge-discharge cycle includes four stages: a discharge energy storage stage, a discharge energy release stage, a charge energy storage stage, and a charge energy release stage. The controller 7 controls the motor control module 3 so that the first capacitor C1 and the power battery 6 are cyclically charged and discharged to realize the battery heating process, that is, the process of cyclically executing the discharge energy storage stage, the discharge energy release stage, the charge energy storage stage, and the charge energy release stage.

[0065] By quickly executing the discharge energy storage stage, discharge energy release stage, charging energy storage stage and charging energy release stage cycles, the battery is continuously charged and discharged, and an oscillating current is formed inside the battery. Due to the existence of the battery's internal resistance, the battery's internal resistance continuously does work, which is ultimately expressed in the form of heat energy, causing the battery itself to generate a large amount of heat, causing the battery to heat up, thereby achieving battery heating.

[0066] In a specific embodiment, if Figure 5a-5d As shown, when the battery self-heating circuit is in the discharge energy storage stage, the upper bridge arm of the high-frequency bridge arm of the motor control module 3 is turned off and the lower bridge arm is turned on, and the low-frequency bridge module 4 may not participate in the control process, such as Figure 5a As shown, the current flows out from the positive electrode of the power battery 6, flows to the second end of the motor winding 2 through the first switch module 8, and then flows from the first end of the motor winding 2 to the lower bridge arm of the high-frequency bridge arm, flows through the switch tube of the lower bridge arm of the high-frequency bridge arm, and flows back to the negative electrode of the power battery 6 through the second switch module 9. The power battery 6, the first switch module 8, the motor winding 2, the lower bridge arm of the high-frequency bridge arm, and the second switch module 9 form a discharge energy storage circuit. In this process, the power battery 6 discharges, the power battery 6 charges the motor winding 2, and the motor winding 2 stores electrical energy.

[0067] When the heating circuit is in the discharge energy release stage, the upper bridge arm of the high-frequency bridge arm is turned on and the lower bridge arm is turned off, and the low-frequency bridge module 4 does not need to participate in the control process. Figure 5bAs shown, the current flows out from the positive electrode of the power battery 6, flows to the second end of the motor winding 2 through the first switch module 8, and then flows from the first end of the motor winding 2 to the upper bridge arm of the high-frequency bridge arm, flows through the switch tube of the upper bridge arm of the high-frequency bridge arm, flows to the first capacitor C1, and then flows out from the first capacitor C1, and flows back to the negative electrode of the power battery 6 through the second switch module 9. The power battery 6, the first switch module 8, the motor winding 2, the upper bridge arm of the high-frequency bridge arm, the first capacitor C1, and the second switch module 9 form a discharge energy release loop. In this process, the power battery 6 discharges, the motor winding 2 releases energy, and the power battery 6 and the motor winding 2 charge the first capacitor C1 together. In this process, the current on the motor winding 2 gradually decreases. When the current on the motor winding 2 is reduced to 0, the voltage on the first capacitor C1 reaches the maximum value. At this time, the charging energy storage stage is entered.

[0068] When the heating circuit is in the charging and energy storage stage, the first switch module 8 and the second switch module 9 are turned on, the upper bridge arm of the high-frequency bridge arm is turned on, and the lower bridge arm is turned off, and the low-frequency bridge module 4 may not participate in the control process. Figure 5c As shown, the current flows out from the first capacitor C1, flows to the motor winding 2 through the switch tube of the upper bridge arm of the high-frequency bridge arm, flows to the positive electrode of the power battery 6 through the first switch module 8, and then flows out from the negative electrode of the power battery 6, and flows back to the first capacitor C1 through the second switch module 9. The first capacitor C1, the upper bridge arm of the high-frequency bridge arm, the motor winding 2, the first switch module 8, the power battery 6, and the second switch module 9 form a charging energy storage loop; in this process, the first capacitor C1 charges the motor winding 2 and the power battery 6, the motor winding 2 stores electrical energy, and the power battery 6 is charged.

[0069] When the heating circuit is in the charging and energy release stage, the first switch module 8 and the second switch module 9 are turned on, the lower bridge arm of the high-frequency bridge arm is turned on, and the upper bridge arm is turned off. The low-frequency bridge module 4 does not need to participate in the control process. Due to the inductance characteristics of the motor winding 2, the current on the motor winding 2 cannot change suddenly. Figure 5d As shown, the current on the motor winding 2 continues to flow to the positive electrode of the power battery 6 after passing through the first switch module 8, then flows out from the negative electrode of the power battery 6, passes through the second switch module 9, flows through the switch tube of the lower bridge arm of the high-frequency bridge arm, and flows back to the motor winding 2. The motor winding 2, the first switch module 8, the power battery 6, the second switch module 9, and the lower bridge arm of the high-frequency bridge arm form a charging and energy release loop. In this process, the motor winding 2 releases energy to charge the power battery 6.

[0070] In this embodiment, the upper bridge arm and the lower bridge arm of the high-frequency bridge arm are controlled to be alternately turned on and off, so that the discharge process of the power battery 6 to the first capacitor C1 and the charging process of the first capacitor C1 to the power battery 6 are alternately performed. Due to the existence of the internal resistance of the battery, the battery itself will generate a large amount of heat, causing the battery to heat up, thereby achieving battery heating.

[0071] In a specific embodiment, in the AC charging mode, the AC charging interface, the motor winding 2, the motor control module 3, the low-frequency bridge module 4, the DC transformer module 5 and the power battery 6 are connected to form an AC charging circuit. Among them, the motor winding 2, the motor control module 3, and the low-frequency bridge module 4 form a PFC module in the vehicle AC charging circuit.

[0072] Specifically, the motor winding 2 is an inductive element in the circuit and can be equivalent to an inductor. By utilizing the characteristic that the current of the energy storage element inductor cannot change suddenly, when the input voltage increases, the current in the series inductor increases, so the inductor will store part of the magnetic field energy. When the current decreases, the energy is released again, making the current smooth and achieving the effect of current filtering. In the AC charging circuit, the winding coil of the motor winding 2 is reused as the filter inductor of the PFC module.

[0073] Furthermore, the high-frequency bridge arm of the motor control module 3 and the low-frequency bridge arm of the low-frequency bridge module 4 are reused as the PFC switch bridge of the PFC module. In the AC charging circuit, the AC charging interface is connected to the external AC power supply equipment, and the PFC switch bridge performs power factor correction to adapt to the grid side frequency, realizes pre-stage rectification, and rectifies the AC power provided by the external AC power supply equipment into DC power.

[0074] When the PFC module and the DC transformer module 5 are connected to the AC charging interface and the battery, they form an AC charging circuit of the vehicle, namely, an OBC circuit.

[0075] In a specific embodiment, in the motor drive mode, the AC charging interface is not connected to the external AC power supply device, the low-frequency bridge module 4 is disconnected, and the motor winding 2, the motor control module 3, the DC transformer module 5 and the power battery 6 are connected to form a motor drive circuit.

[0076] Specifically, the on and off of the three-phase bridge arm of the motor control module 3 is controlled so that the current forms a loop between any two-phase bridge arms in turn, generates vector current, forms a rotating magnetic field, and then drives the rotor of the motor winding 2 to rotate, so that the motor winding 2 outputs torque.

[0077] In this embodiment, in the AC charging mode, the motor winding 2, the motor control module 3, and the low-frequency bridge module 4 can form a PFC module in the vehicle AC charging circuit for AC charging. The motor winding 2 and the motor control module 3 can also form a motor drive circuit for driving the motor. The energy conversion device of the present application reuses the motor winding 2 and the motor control module 3 of the motor drive circuit while minimizing the cost, and can also be used to realize the battery charging function. The motor winding 2 can be a motor of a vehicle functional device, for example, it can be a power motor of the vehicle, it can be a vehicle steering assist motor, it can also be a compressor motor, and so on. In this embodiment, the vehicle's power steering motor is preferred. Since the power steering motor is generally arranged on the steering shaft or the drive shaft, a high-voltage distribution box branches out a line from the busbar of the power battery 6 pack for power supply. The on-board charger connects the charging port and the battery pack. The power steering motor and the on-board charger have the functions of two modules, and the application scenarios are mutually exclusive. The electric power steering gear only needs to work when the vehicle is started and allowed to drive, and the vehicle has no need to be charged while driving; the on-board charger only needs to work when the vehicle is stationary during AC charging / external discharge, and the vehicle has no need for power steering while charging.

[0078] In another embodiment, the high-frequency bridge arm module in the OBC circuit may be reused as the motor control module 3, and the filter inductor in the OBC circuit may be reused as the motor winding 2 to realize the motor driving function.

[0079] An energy conversion device provided by the present invention deeply integrates a motor drive circuit with an AC charging circuit, optimizes the topology of the two circuits, reuses power switching devices and power inductors, and can realize both AC charging and motor drive functions in one circuit structure without adding a mode switching switch, thereby simplifying the control circuit structure, reducing the use of multiple high-power devices, optimizing the layout space of the entire vehicle, and greatly reducing production costs.

[0080] like Figure 4 As shown, in the motor drive mode, the motor winding 2, the motor control module 3, the DC transformer module 5 and the power battery 6 are controlled to form a motor drive circuit.

[0081] Specifically, Figure 4As shown, the AC charging interface is not connected to the external AC power supply device, that is, the neutral point of the motor winding 2 is not connected to the AC charging interface, and the low-frequency bridge arms of the low-frequency bridge module 4 are all turned off, which is equivalent to the low-frequency bridge arm module not being connected to the two ends of the motor control module 3. At this time, the circuit is equivalent to one end of the winding coil of the motor winding 2 being connected in common, and the other end of the winding coil of the motor winding 2 is connected one by one to the midpoint of the high-frequency bridge arm of the motor control module 3, respectively. The motor control module 3 is connected to the power battery 6 through the DC transformer module 5. When the motor control module 3 has a driving demand, the current flows out from the power battery 6, is inverted and rectified by the DC transformer module 5, and reaches the motor control module 3. By controlling the conduction and closure of the three groups of upper and lower bridge arms of the high-frequency bridge arm of the motor control module 3, the current forms a loop between the bridge arms, generates a vector current, and forms a rotating magnetic field, thereby driving the rotor of the motor winding 2 to rotate, so that the motor winding 2 outputs torque.

[0082] In a specific embodiment, in the motor driving mode, when the multi-phase high-frequency bridge arm of the motor control module 3 is controlled, the multi-phase high-frequency bridge arm is controlled to form a current vector so that the motor winding 2 outputs torque.

[0083] Specifically, in the motor drive mode, the AC charging interface is not connected to the external AC power supply device, and the power battery 6 is converted and rectified by the DC transformer module 5 to provide a power source for the motor drive. By controlling the on and off of the high-frequency bridge arm of the motor control module 3, the current forms a current vector in the multi-phase high-frequency bridge arm, forming a rotating magnetic field, so that the rotor of the motor winding 2 rotates to output torque. Taking the three-phase motor as an example, in the existing motor vector control, a seven-segment space voltage vector control method is usually adopted. The power device of the three-phase voltage inverter of the AC induction motor is controlled by the combination of the switch trigger sequence and the pulse width. The reference voltage vector of the stator is obtained by the combination of the switch state corresponding to the basic space vector, which will produce fewer harmonics in the output voltage or the current in the coil of the motor winding 2, improve the torque quality, reduce the pulsating torque generated by the motor, make the machine vibrate less, the output signal has fewer harmonics, the waveform quality clarity is better, and the power supply voltage is more stable.

[0084] like Figure 3 As shown, in the AC charging mode, the AC charging interface, the motor winding 2, the motor control module 3, the low-frequency bridge module 4, the DC transformer module 5 and the power battery 6 are controlled to form an AC charging circuit.

[0085] Specifically, Figure 3The AC charging interface shown is connected to an external AC power supply device. After the vehicle successfully shakes hands with the external AC power supply device, the AC power provided by the external AC power supply device flows in through the neutral line of the motor winding 2, is filtered by the motor winding 2, and is rectified into DC power through the PFC switch bridge formed by the motor control module 3 and the low-frequency bridge module 4 for power factor correction. The DC transformer module 5 converts the rectified and filtered DC power into AC power and performs power conversion through the internal transformer unit, and then converts the AC power after the power change into DC power to charge the battery.

[0086] In AC charging mode and battery self-heating mode, when the multi-phase high-frequency bridge arm of the motor control module 3 is controlled, the upper bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, or the lower bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, and the motor winding 2 outputs zero vector.

[0087] In a specific embodiment, during AC charging or battery self-heating, when the multi-phase high-frequency bridge arm of the high-frequency bridge arm is controlled, the upper bridge arm of the multi-phase high-frequency bridge arm is turned on at the same time, or the lower bridge arm of the multi-phase high-frequency bridge arm is turned on at the same time. In order to avoid the formation of current vectors and magnetic fields due to the existence of currents in different directions between the windings of different phases in the motor windings, so that the winding unit produces pulsating torque, which has a great impact on the safety of the device, therefore, in the preferred embodiment of the present application, the controller 77 can control the multi-phase high-frequency bridge arm in the high-frequency bridge arm, so that the upper bridge arm of the multi-phase high-frequency bridge arm is turned on at the same time, or the lower bridge arm of the multi-phase high-frequency bridge arm is turned on at the same time. Since the control of the multi-phase bridge arm is exactly the same, the current vector of the motor winding is zero, and there will be no torque pulsation, thereby improving the safety of the appliance during AC charging and battery self-heating.

[0088] On the other hand, the present application provides a vehicle 200 . FIG5 is a schematic diagram of a vehicle according to an exemplary embodiment of the present application. The vehicle 200 includes the above energy conversion device 100 .

[0089] Regarding the device in the above embodiment, the connection method of each module and the specific method of performing operations have been described in detail in the embodiment of the device, and will not be elaborated here.

[0090] The preferred embodiments of the present application are described in detail above in conjunction with the accompanying drawings; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0091] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

[0092] In addition, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. An energy conversion device, characterized in that: include: Motor control module; A motor winding, wherein the neutral point of the motor winding is connected to the positive pole of the AC charging interface, and the other end of the motor winding is connected to the motor control module; A low-frequency bridge module, wherein a first end of the low-frequency bridge module is connected to a first bus terminal of the motor control module, a second end of the low-frequency bridge module is connected to a second bus terminal of the motor control module, and a negative pole of the AC charging port is connected to a midpoint of the low-frequency bridge module; A DC transformer module, wherein a first end of the DC transformer module is connected to a first end of the low-frequency bridge module, and a second end of the DC transformer module is connected to a second end of the low-frequency bridge module; a third end of the DC transformer module is connected to a positive electrode of a power battery, and a fourth end of the DC transformer module is connected to a negative electrode of the power battery; A controller configured to: in a motor drive mode, control the motor winding, the motor control module, the DC transformer module and the power battery to form a motor drive circuit; In the AC charging mode, the AC charging interface, the motor winding, the motor control module, the low-frequency bridge module, the DC transformer module and the power battery are controlled to form an AC charging circuit; Wherein, the device further comprises: A first switch module, wherein a first end of the first switch module is connected to the positive electrode of the AC charging interface, and a second end of the first switch module is connected to the positive electrode of the power battery; a second switch module, wherein a first end of the second switch module is connected to a second bus terminal of the motor control module, and a second end of the second switch module is connected to a negative electrode of the power battery; The controller is configured to: in a battery self-heating mode, control the first switch module and the second switch module to be turned on, and the motor control module, the motor winding, the first switch module, the second switch module, the DC transformer module and the battery form a battery self-heating circuit.

2. The energy conversion device according to claim 1, characterized in that: The controller is configured to: in a motor drive mode, control the first switch module and the second switch module to be disconnected, and control the motor winding, the motor control module, the DC transformer module and the power battery to form a motor drive circuit; In the AC charging mode, the first switch module and the second switch module are controlled to be disconnected, and the AC charging interface, the motor winding, the motor control module, the low-frequency bridge module, the DC transformer module and the power battery are controlled to form an AC charging circuit.

3. The energy conversion device according to claim 2, characterized in that: The motor winding comprises a multi-phase winding coil, one end of which is connected in common to form a neutral point; The motor control module includes a multi-phase high-frequency bridge arm, the first ends of the multi-phase high-frequency bridge arms are connected together to form a first bus terminal of the motor control module, the second ends of the multi-phase high-frequency bridge arms are connected together to form a second bus terminal of the motor control module, and the midpoint of each phase high-frequency bridge arm is connected to the other end of each phase winding coil; wherein the number of phases of the high-frequency bridge arm is equal to the number of phases of the winding coil.

4. The energy conversion device according to claim 3, characterized in that: The low-frequency bridge module includes at least one phase of low-frequency bridge arm, the first ends of all the low-frequency bridge arms form the first end of the low-frequency bridge module, the second ends of all the low-frequency bridge arms form the second end of the low-frequency bridge module, and the midpoints of all the low-frequency bridge arms are connected to the negative pole of the AC charging port.

5. The energy conversion device according to claim 4, characterized in that: The DC transformer module comprises: a first capacitor, an AC side power switch unit, a transformer unit, a battery side power switch unit and a second capacitor, wherein the transformer unit is connected to the AC side power switch unit and the battery side power switch unit respectively; The first end of the first capacitor and the first end of the AC side power switch unit are connected together to form the first end of the DC transformer module, and the second end of the first capacitor and the second end of the AC side power switch unit are connected together to form the second end of the DC transformer module; The first end of the second capacitor and the first end of the battery-side power switch unit are connected together to form the third end of the DC transformer module, and the second end of the first capacitor and the second end of the battery-side power switch unit are connected together to form the fourth end of the DC transformer module.

6. The energy conversion device according to claim 5, characterized in that: In the battery self-heating mode, the controller controls the motor control module so that the first capacitor of the DC transformer module and the power battery are cyclically charged and discharged according to a charge and discharge cycle, and the charge and discharge cycle includes: a discharge energy storage stage, a discharge energy release stage, a charge energy storage stage, and a charge energy release stage.

7. The energy conversion device according to claim 6, characterized in that: When the battery self-heating circuit is in the discharging energy storage stage, the battery, the first switch module, the motor winding, the lower bridge arm of the high-frequency bridge arm, and the second switch module form a discharging energy storage loop; When the battery self-heating circuit is in the discharge energy release stage, the power battery, the first switch module, the motor winding, the upper bridge arm of the high-frequency bridge arm, the first capacitor, and the second switch module form a discharge energy release loop; When the battery self-heating circuit is in the charging energy storage stage, the first capacitor, the upper bridge arm of the high-frequency bridge arm, the motor winding, the first switch module, the power battery, and the second switch module form a charging energy storage loop; When the battery self-heating circuit is in the charging and energy release stage, the motor winding, the first switch module, the power battery, the second switch module, and the lower bridge arm of the high-frequency bridge arm form a charging and energy release loop.

8. The energy conversion device according to claim 1, characterized in that: In the motor driving mode, when the multi-phase high-frequency bridge arm of the motor control module is controlled, the multi-phase high-frequency bridge arm is controlled to form a current vector so that the motor winding outputs torque.

9. The energy conversion device according to claim 2, characterized in that: In the AC charging mode and the battery self-heating mode, when the multi-phase high-frequency bridge arm of the motor control module is controlled, the upper bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, or the lower bridge arms of the multi-phase high-frequency bridge arms are turned on at the same time, and the motor winding has no torque output.

10. A vehicle, characterized in that: The invention comprises a battery and an energy conversion device according to any one of claims 1 to 9.

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