Energy conversion system, charging and discharging control method and heating control method of vehicle

Abstract

The invention provides an energy conversion system, a charging and discharging control method and a heating control method of a vehicle. The system comprises two groups of multiphase inverters of an electric drive system, at least one group of multiphase windings, a first capacitor, a second capacitor and a controller, a bus of the first group of multi-phase inverters is connected with the battery and the first capacitor in parallel, a bus of the second group of multi-phase inverters is connected with the second capacitor and the external equipment in parallel, the bus of the second group of multi-phase inverters is in on-off connection with the external equipment through the first switch, and the first group of multi-phase inverters and the second group of multi-phase inverters are connected through at least one pole of bus. The at least one group of multi-phase windings is correspondingly connected to the midpoints of the bridge arms of the two groups of multi-phase inverters respectively; one pole between the battery and the external equipment is directly connected through the second switch in an on-off manner; and the controller is connected to the first switch, the second switch and the two groups of multi-phase inverters so as to control the on-off of the first switch and drive the two groups of multi-phase inverters to act, so that the buck-boost charging and discharging of the vehicle or the battery heating of the vehicle is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to an energy conversion system of a vehicle, a method for controlling charging and discharging of a vehicle, and a method for controlling battery heating of a vehicle. Background Art

[0002] There are currently two solutions to the problem of voltage conversion between vehicles and external devices. The first solution is to add additional voltage conversion equipment, which increases the production cost and volume of the entire vehicle. The second solution is to reuse the vehicle's motor drive system to achieve voltage conversion. However, this solution cannot achieve both boost and buck at the same time, which affects the coverage of its usage scenarios.

[0003] In addition, low temperature environment will deteriorate battery performance, reduce battery power output, affect battery capacity, safety and charging speed, and preheating is the mainstream solution. The external heating solution uses a medium as an intermediate link to transfer heat, which has low efficiency, poor uniformity and long heating time. In low temperature environment, the internal resistance of the battery will rise sharply. By using this characteristic to charge and discharge the battery, the current flows through the internal resistance of the battery to generate ohmic heat and other internal heating of the battery. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an AC energy conversion system for a vehicle, a control method for charging and discharging a vehicle, and a battery heating control method for a vehicle, so as to realize the boost and buck charging and discharging of the vehicle and the battery heating functions of the vehicle by reusing the vehicle electric drive system.

[0005] In order to solve or improve the above technical problems to a certain extent, according to one aspect of the present invention, there is provided an energy conversion system for a vehicle, comprising: two sets of multi-phase inverters of a vehicle electric drive system, at least one set of multi-phase windings, a first capacitor, a second capacitor and a controller;

[0006] The busbars of the first group of multi-phase inverters are connected in parallel with the battery of the vehicle and the first capacitor, the busbars of the second group of multi-phase inverters are connected in parallel with the second capacitor and an external device, and the busbars of the second group of multi-phase inverters are connected to the external device in an on-off manner through a first switch, at least one pole of the busbars of the first group of multi-phase inverters and the second group of multi-phase inverters are connected to each other, and at least one group of multi-phase windings are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters; one pole between the battery and the external device is directly connected in an on-off manner through a second switch;

[0007] The controller is connected to the first switch, the second switch and the two groups of multi-phase inverters to control the on and off of the first switch and drive the two groups of multi-phase inverters to operate, so as to realize the boost / lower voltage charging and discharging of the vehicle or the battery heating of the vehicle.

[0008] In some embodiments, the multi-phase winding is a group of multi-phase windings with an open neutral point, and both ends of the multi-phase winding are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters.

[0009] In some embodiments, there are two groups of multi-phase windings, one ends of the two groups of multi-phase windings are connected to each other through a neutral point, and the other ends of the two groups of multi-phase windings are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters.

[0010] In some embodiments, the first busbars of the first group of multi-phase inverters are directly connected to the first busbars of the second group of multi-phase inverters;

[0011] The second busbars of the first group of multi-phase inverters are not connected to the second busbars of the second group of multi-phase inverters, or

[0012] The second busbars of the first group of multi-phase inverters are connected to the second busbars of the second group of multi-phase inverters in an on-off manner through a third switch.

[0013] In some embodiments, the first busbar of the first group of multi-phase inverters is directly connected to the first busbar of the second group of multi-phase inverters, and the second busbar of the first group of multi-phase inverters is not connected to the second busbar of the second group of multi-phase inverters;

[0014] There are two groups of multi-phase windings, one end of the first group of multi-phase windings is respectively connected to the midpoint of the bridge arm of the first group of multi-phase inverters, and the neutral point of the first group of multi-phase windings can be connected to the second bus of the second group of multi-phase inverters through a fourth switch, and one end of the second group of multi-phase windings is respectively connected to the midpoint of the bridge arm of the second group of multi-phase inverters, and the neutral point of the second group of multi-phase windings can be connected to the second bus of the first group of multi-phase inverters through a fifth switch.

[0015] In some embodiments, electrical energy conversion is performed between the battery and the energy storage device to generate a high-frequency alternating current to pass through the battery, and the battery is heated by the thermal effect of the current.

[0016] In some implementations, the controller controls the two groups of bridge arm switches of the multi-phase inverters to operate synchronously to generate the high-frequency alternating current with variable amplitude and frequency.

[0017] According to an embodiment of the present invention, a vehicle charging and discharging control method is provided, which is applied to the energy conversion system of the vehicle described in any one of the above embodiments, and the method includes:

[0018] After detecting that the charging and discharging gun is inserted, the charging and discharging data is obtained;

[0019] Selecting a corresponding charging and discharging mode according to the charging and discharging data, wherein the charging and discharging mode includes: a boost charging mode, a buck charging mode, a boost discharging mode, a buck discharging mode, a direct charging mode, and a direct discharging mode;

[0020] The operation of the vehicle's energy conversion system is controlled based on the selected charging and discharging mode.

[0021] According to an embodiment of the present invention, a battery heating control method for a vehicle is provided, which is applied to the energy conversion system of the vehicle described in any one of the above embodiments, and the method includes:

[0022] Obtain heating data of vehicle battery;

[0023] Selecting a corresponding heating mode according to the heating data, the heating mode including a pulse heating mode and a resonance heating mode;

[0024] Operation of an energy conversion system of the vehicle is controlled based on the selected heating mode.

[0025] According to an embodiment of the present invention, a vehicle is provided, comprising the vehicle energy conversion system described in any one of the above embodiments.

[0026] According to one embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle charging and discharging control method described in any of the above embodiments can be implemented.

[0027] According to an embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle battery heating control method described in any of the above embodiments can be implemented.

[0028] According to an embodiment of the present invention, a computer-readable storage medium is provided for storing a computer program, wherein the program, when executed by a computer or a processor, implements the steps of the vehicle charging and discharging control method described in any of the above-mentioned embodiments.

[0029] According to an embodiment of the present invention, a computer-readable storage medium is provided for storing a computer program, wherein when the program is executed by a computer or a processor, the program implements the steps of the vehicle battery heating control method described in any of the above embodiments.

[0030] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the vehicle energy conversion system, the vehicle charging and discharging control method and the vehicle battery heating control method of the present invention can achieve considerable technical advancement and practicality, and have wide industrial utilization value, and have at least the following advantages:

[0031] The energy conversion system of the vehicle of the present invention reuses the electric drive system of the vehicle. When the vehicle battery is charged and discharged, it can realize any one of the four modes of boost charging, buck charging, boost discharge and buck discharge, which can meet the mutual compatibility and optimal power transmission between the vehicle battery and external devices of platforms with different voltage equipolarity. When heating the vehicle battery, it can directly generate high-frequency current to form internal resistance heating of the battery, directly heat the battery, greatly improve the heating speed, greatly improve the heating efficiency, and do not need to rely on the cooling circuit.

[0032] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A topological diagram of an energy conversion system for a vehicle according to a first embodiment of the present invention;

[0034] Figure 2 A topological diagram of an energy conversion system for a vehicle according to a second embodiment of the present invention;

[0035] Figure 3 A topological diagram of an energy conversion system for a vehicle according to a third embodiment of the present invention;

[0036] Figure 4 A topological diagram of an energy conversion system for a vehicle according to a fourth embodiment of the present invention;

[0037] Figure 5 A topological diagram of an energy conversion system for a vehicle according to a fifth embodiment of the present invention;

[0038] Figure 6 A topological diagram of an energy conversion system for a vehicle according to a sixth embodiment of the present invention;

[0039] Figure 7 A topological schematic diagram of an energy conversion system for a vehicle according to a seventh embodiment of the present invention;

[0040] Figure 8 A topological diagram of an energy conversion system for a vehicle according to an eighth embodiment of the present invention;

[0041] Fig. 9 A topological schematic diagram of an energy conversion system for a vehicle according to a ninth embodiment of the present invention;

[0042] Fig.10 A topological diagram of an energy conversion system for a vehicle according to a tenth embodiment of the present invention;

[0043] Fig.11 A schematic flow chart of a method for controlling vehicle charging and discharging according to an embodiment of the present invention;

[0044] Fig.12 A schematic flow chart of a vehicle charging and discharging control method according to another embodiment of the present invention;

[0045] Fig.13 A schematic flow chart of a method for controlling battery heating of a vehicle according to an embodiment of the present invention;

[0046] Fig.14 FIG. 4 is a flow chart of a method for controlling battery heating of a vehicle according to another embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods and effects of the energy conversion system, charging and discharging control method and heating control method of the vehicle proposed in the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0048] Figure 1-10 FIG. 1 shows a schematic diagram of the topological structure of the energy conversion system of a vehicle of the present invention. Figure 1-10 As shown, the vehicle's energy conversion system reuses the vehicle's electric drive system to reduce the production cost of the entire vehicle, reduce the weight of the vehicle, and optimize the spatial layout of the entire vehicle.

[0049] The energy conversion system of the vehicle comprises: two sets of multi-phase inverters (10, 20) of the vehicle electric drive system, at least one set of multi-phase windings 30, a first capacitor C1 and a second capacitor C2, and a controller (not shown in the figure).

[0050] The energy conversion system of the vehicle of the present invention reuses the electric drive system of the vehicle, and can realize any one of the four modes of boost charging, buck charging, boost discharge and buck discharge when the vehicle battery is charged and discharged, and can meet the mutual compatibility and optimal power transmission between the vehicle battery and external devices of platforms with different voltage levels. When heating the vehicle battery, it can directly generate high-frequency current to form internal resistance heating of the battery, directly heat the battery, and the heating speed is greatly improved, which greatly improves the heating efficiency, and does not need to rely on the cooling circuit.

[0051] like Figure 1-10As shown, the busbar of the first multi-phase inverter 10 is connected in parallel with the battery of the vehicle and the first capacitor C1, the busbar of the second multi-phase inverter 20 is connected in parallel with the second capacitor C2 and the external device, and the busbar of the second multi-phase inverter 20 and the external device can be connected and disconnected through the first switch K1.

[0052] The two-pole (i.e., positive and negative) busbars of the first multi-phase inverter 10 are respectively connected to the two ends of the first capacitor C1 and the two-pole (i.e., positive and negative) busbars of the vehicle battery. That is, the first multi-phase inverter 10 is connected in parallel with the first capacitor C1 and the vehicle battery.

[0053] like Figure 1-10 As shown, the busbar of the second multi-phase inverter 20 is connected in parallel with the second capacitor C2 and the external device, and the busbar of the second multi-phase inverter 20 and the external device can be switched on and off through the first switch K1.

[0054] The two-pole (i.e., positive and negative) busbars of the second multi-phase inverter 20 are respectively connected to the two ends of the first capacitor C1 and the two-pole (i.e., positive and negative) busbars of the external device. That is, the second multi-phase inverter 20 is connected in parallel with the second capacitor C2 and the external device. The first switch K1 is arranged between the second capacitor C2 and the external device, so that the on-off between the external device and the second multi-phase inverter 20 is controlled by the first switch K1.

[0055] Specifically, the first switch K1 is disposed between one pole (positive pole or negative pole) of the busbar of the second group of multi-phase inverters 20 and the external device.

[0056] Optionally, the external device is a charging device or a power-consuming device.

[0057] like Figure 1-10 As shown, at least one bus bar (positive or negative) between the first group of multi-phase inverters 10 and the second group of multi-phase inverters 20 is connected to each other.

[0058] In one embodiment, if Figure 1 , 2 As shown in Figures 6 and 7, the first busbar (e.g., ground terminal, negative pole) of the first group of multi-phase inverters 10 is directly connected to the first busbar of the second group of multi-phase inverters 20, and the second busbar of the first group of multi-phase inverters 10 is connected to the second busbar (e.g., positive pole) of the second group of multi-phase inverters 20 in an on-off manner through a third switch K3.

[0059] In one embodiment, as shown in FIG. Figure 3 , 4 , 8 and 9 , the first busbar of the first group of multi-phase inverters 10 is directly connected to the first busbar of the second group of multi-phase inverters 20 , and the second busbar of the first group of multi-phase inverters 10 is not connected to the second busbar of the second group of multi-phase inverters 20 .

[0060] In the above embodiment, the first busbars of the first group of multi-phase inverters 10 and the second group of multi-phase inverters 20 can be either a positive busbar or a negative busbar. Similarly, the second busbars of the first group of multi-phase inverters 10 and the second group of multi-phase inverters 20 can be either a negative busbar or a positive busbar.

[0061] like Figure 1-10 As shown, at least one group of multi-phase windings 30 is respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters (10, 20).

[0062] Optionally, when the multi-phase windings 30 are a group, the neutral point of the group of multi-phase windings 30 is opened, and the two ends of the multi-phase windings 30 are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters (10, 20).

[0063] In one embodiment, if Figure 2 , 4 As shown in , 7 and 9, the multi-phase winding 30 is a group, and the neutral point of the multi-phase winding 30 is opened, one end of the multi-phase winding 30 is respectively connected to the midpoint of the bridge arm of the first group of multi-phase inverters 10, and the other end of the multi-phase winding 30 is respectively connected to the midpoint of the bridge arm of the second group of multi-phase inverters 20.

[0064] Optionally, there are two groups of multi-phase windings 30, the neutral points of one end of the two groups of multi-phase windings 30 are connected to each other, and the other ends of the multi-phase windings 30 are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters (10, 20).

[0065] In one embodiment, if Figure 1 , 3 As shown in , 6 and 8, there are two groups of multi-phase windings 30, and the neutral points of the two groups of multi-phase windings 30 are connected to each other, one end of one multi-phase winding 30 is respectively connected to the midpoint of the bridge arm of the first group of multi-phase inverters 10, and one end of the other multi-phase winding 30 is respectively connected to the midpoint of the bridge arm of the second group of multi-phase inverters 20.

[0066] In one embodiment, if Figure 5 and 10As shown, the first busbar of the first group of multiphase inverters 10 is directly connected to the first busbar of the second group of multiphase inverters 20, and the second busbar of the first group of multiphase inverters 10 is not connected to the second busbar of the second group of multiphase inverters 20. There are two groups of multiphase windings 30, one end of the first group of multiphase windings 30 is respectively connected to the middle point of the bridge arm of the first group of multiphase inverters 10, and the neutral point of the first group of multiphase windings 30 is connected to the second busbar of the second group of multiphase inverters through the fourth switch K4, and one end of the second group of multiphase windings 30 is respectively connected to the middle point of the bridge arm of the second group of multiphase inverters 20, and the neutral point of the second group of multiphase windings 30 is connected to the second busbar of the first group of multiphase inverters 10 through the fifth switch K5.

[0067] In the above embodiment, when there are two groups of multi-phase windings 30, the two groups of multi-phase windings 30 can be placed in different pole pairs using one motor, or one group of multi-phase windings 30 can be selected from each of the two motors.

[0068] In one embodiment, if Figure 1-10 As shown, the battery of the vehicle is directly connected to the external device in a disconnectable manner.

[0069] Alternatively, if Figure 1-5 As shown, one pole (positive or negative) of the battery of the vehicle is directly connected to one pole (positive or negative) of the external device through the second switch K2. In this embodiment, the battery of the vehicle and the external device can be directly connected at the negative pole or at the positive pole.

[0070] Optionally, the positive and negative poles of the battery of the vehicle can be directly connected to the positive and negative poles of the external device in an on-off manner. Figure 6-10 As shown, the negative electrode of the vehicle battery is directly connected to the negative electrode of the external device through the second switch K2, and the positive electrode of the vehicle battery is directly connected to the positive electrode of the external device through the sixth switch K6.

[0071] In this embodiment, by directly connecting the battery of the vehicle to an external device, the energy conversion system of the vehicle can also realize direct charging and discharging of the battery of the vehicle.

[0072] In the above embodiment, when the battery of the vehicle is directly charged and discharged, the busbars of two sets of multi-phase inverters (10, 20) can be used to realize the transmission of electric energy, or a connecting line can be independently set between the vehicle battery and the external device, and can be connected in an on-off manner to avoid coupling with the vehicle's electric drive system during the direct charging and discharging process.

[0073] The controller of the vehicle's energy conversion system is connected to a first switch K1, a second switch K2 and two sets of multi-phase inverters (10, 20) to control the on and off of the first switch K1 and the second switch K2 and drive the two sets of multi-phase inverters (10, 20) to operate, so as to realize boost / lower voltage charging and discharging of the vehicle or battery heating of the vehicle.

[0074] Specifically, in the vehicle charging and discharging scenario, the voltage level and charging and discharging requirements of the external equipment are judged through messages or voltage detection devices, and one of boost charging, buck charging, boost discharging, and buck discharging is selected in combination with the real-time charging and discharging capabilities of the battery.

[0075] When the boost charging, buck discharging, buck charging or boost discharging mode is selected, the controller controls the bridge arm switches of the two sets of multi-phase inverters (10, 20) to charge the second capacitor C2 to the target voltage. Then the first switch K1 and the second switch K2 are controlled to close to enter the boost charging or buck discharging process. The controller controls the bridge arm switches of the two sets of multi-phase inverters (10, 20) to complete the boost charging or buck discharging process.

[0076] In some of the above embodiments, such as Figure 1 and 2 As shown, when the second busbars of the first multi-phase inverter 10 and the second multi-phase inverter 20 are connected in a switchable manner through the third switch K3, the controller is also connected to the third switch K3. At this time, the charging and discharging scenario also includes a direct charging and discharging mode, that is, the battery of the vehicle is directly connected to the external device without boosting or reducing the voltage.

[0077] When the direct charge and discharge mode is selected, the controller controls the first switch K1 , the second switch K2 and the third switch K3 to be closed.

[0078] In some of the above embodiments, such as Figure 6-10 As shown, when the negative electrode of the vehicle battery is directly connected to the negative electrode of the external device through the second switch K2, and the positive electrode of the vehicle battery is directly connected to the positive electrode of the external device through the sixth switch K6, the controller is also connected to the sixth switch K6. At this time, the charging and discharging scenario also includes a direct charging and discharging mode, that is, the battery of the vehicle is directly connected to the external device without boosting or reducing the voltage.

[0079] When the direct charge and discharge mode is selected, the controller controls the first switch K1 and the third switch K3 to be disconnected, and controls the second switch K2 and the sixth switch K6 to be closed.

[0080] Specifically, in a battery heating scenario, the controller controls the step-up or step-down electrical energy conversion between the vehicle's battery and the energy storage device to generate a high-frequency alternating current through the vehicle's battery, using the thermal effect of the current to heat the battery.

[0081] Optionally, the energy storage device is a multi-phase winding 30 or a second capacitor C2 of the electric drive system.

[0082] In one embodiment, when controlling the step-up or step-down electric energy conversion between the battery and the energy storage device of the vehicle, the controller controls the bridge arm switches of two groups of multi-phase inverters (10, 20) to operate synchronously to generate a high-frequency alternating current with variable amplitude and frequency, and the modulation wave of the synchronous operation of the bridge arm switches of the multi-phase inverter contains a DC component and an AC component.

[0083] In this embodiment, by controlling the bridge arms of the multi-phase inverter (10, 20) to operate simultaneously, it is ensured that the currents of the multi-phases of the inverter are the same in real time, the motor torque is completely eliminated, and the serious NVH problem caused by the low-order pulsating torque in the pulse heating of the multiplexed electric drive system is avoided; in addition, by selecting an energy storage device to use any waveform of pulse or sine, the duty cycle can be modulated to achieve real-time variable current amplitude / frequency / waveform to adapt to the battery heating requirements under different working conditions.

[0084] In one embodiment, if Figure 1 As shown, in the battery heating scenario, one of the three modes of inductive pulse heating, boost resonant heating, and buck resonant heating is selected according to the battery heating demand and component stress.

[0085] When the inductive pulse heating mode is selected, the controller controls the first switch K1 and the second switch K2 to be disconnected and the third switch K3 to be closed, and controls the upper bridge arm switches of the two groups of multi-phase inverters (10, 20) to be turned on and off simultaneously through an open-loop table lookup or a duty cycle signal of a closed-loop control, and to be turned on complementary to the lower bridge arm switches of the two groups of multi-phase inverters (10, 20), thereby generating a high-frequency pulse current with a target amplitude / frequency required by the battery in real time to heat the battery.

[0086] When the boost resonant heating mode or the buck resonant heating mode is selected, the first switch K1, the second switch K2 and the third switch K3 are controlled to be disconnected, and the on and off of the bridge arm switches of the two groups of multi-phase inverters (10, 20) are controlled by the duty cycle signal of the open-loop table lookup or closed-loop control, and the second capacitor C2 is precharged to the target DC voltage and maintained. The target value of the AC component of the heating current is given by the table lookup according to the real-time demand of the battery, and the error is subtracted from the neutral point current collected in real time by the current sensor. The error is output through the multi-order quasi-proportional resonant controller to output the AC duty cycle, which is superimposed with the DC duty cycle signal. The superimposed duty cycle signal is modulated and controlled to control the bridge arm switch action of the two groups of multi-phase inverters (10, 20), so that a high-frequency sinusoidal AC heating current with the target amplitude / frequency required by the battery in real time flows through the battery.

[0087] In some specific embodiments, Figure 1As shown, the phase winding LA1 of the motor A1, the phase winding LB1 of the motor B1, and the phase winding LC1 of the motor C1 constitute a first group of three-phase windings, the phase winding LA2 of the motor A2, the phase winding LB2 of the motor B2, and the phase winding LC2 of the motor C2 constitute a second group of three-phase windings, and the two groups of three-phase windings are connected through a neutral point; the main inverter (i.e., the first group of multi-phase inverters 10) is composed of a three-phase bridge arm composed of a switching device Q1, a switching device Q2, a switching device Q3, a switching device Q4, a switching device Q5, and a switching device Q6, and is correspondingly connected to the first group of three-phase windings; the auxiliary inverter (i.e., the second group of multi-phase inverters The inverter 20) is composed of a three-phase bridge arm consisting of a switch device Q7, a switch device Q8, a switch device Q9, a switch device Q10, a switch device Q11, and a switch device Q12, and is connected to the second group of three-phase windings accordingly; one end of the busbars of the two groups of inverters is directly connected, and the other end of the busbars is connected in a switchable manner by a relay K3 (i.e., a third switch); both ends of the main inverter busbar are connected in parallel to the busbar capacitor C1 (i.e., the first capacitor C1) and the two ends of the battery busbar, and both ends of the auxiliary inverter busbar are connected in a switchable manner in parallel to the external device interface through a relay K1 (i.e., the first switch) and a relay K2 (i.e., the second switch);

[0088] Charging and discharging scenarios: The voltage level and charging and discharging requirements of external devices are determined through messages or voltage detection devices. Combined with the real-time charging and discharging capabilities of the battery, one of the six modes of boost charging, buck charging, boost discharging, buck discharging, direct charging, and direct discharging is determined.

[0089] Entering the boost charging or buck discharging mode, the charging and discharging capacitor C2 (i.e., the second capacitor) is pre-charged to the target voltage by controlling the two sets of inverter bridge arm switches, and then K1 and K2 are closed, and K3 is kept disconnected. After entering the boost charging process, Q7 / Q9 / Q11 is kept turned on and Q8 / Q10 / Q12 is disconnected. The boost charging of the battery is achieved by controlling Q1 / Q2 / Q3 / Q4 / Q5 / Q6.

[0090] Entering the buck charging or boost discharging mode, the charging and discharging capacitor C2 is pre-charged to the target voltage by controlling the two sets of inverter bridge arm switches, and then K1 and K2 are closed, and K3 is kept disconnected. After entering the boost charging process, Q1 / Q3 / Q5 are kept turned on and Q2 / Q4 / Q6 are disconnected. The battery is buck-charged by controlling Q7 / Q8 / Q9 / Q10 / Q11 / Q12.

[0091] To enter the direct charge and discharge mode, close K1, K2, and K3.

[0092] Battery heating scenario: Determine one of the three modes: inductive pulse heating, boost resonant heating, and buck resonant heating based on battery heating demand and component stress.

[0093] Enter the inductive pulse heating mode, keep K1 / K2 open, close K3, and control Q1 / Q3 / Q5 / Q8 / Q10 / Q12 to turn on and off at the same time through the duty cycle signal of open-loop table lookup or closed-loop control, and complement with Q2 / Q4 / Q6 / Q7 / Q9 / Q11 to generate a high-frequency pulse current with the target amplitude / frequency required by the battery in real time to heat the battery.

[0094] Enter the boost resonant heating mode, keep K1 / K2 / K3 disconnected, keep Q1 / Q3 / Q5 turned on, Q2 / Q4 / Q6 disconnected, Q7 / Q9 / Q11 turned on and off at the same time, and turned on complementary with Q8 / Q10 / Q12, and control the action of Q7 / Q9 / Q11 through the duty cycle signal of open-loop table lookup or closed-loop control, precharge the capacitor C2 to the target DC voltage and maintain it. The AC component target value of the heating current is given by the table lookup according to the real-time demand of the battery, and the error is subtracted from the neutral point current collected in real time by the current sensor. The error is output as the AC duty cycle through the multi-order quasi-proportional resonant controller and superimposed with the DC duty cycle signal. The superimposed duty cycle signal is modulated and controlled by Q7 / Q9 / Q11 to generate a high-frequency sinusoidal AC heating current with the target amplitude / frequency required by the battery in real time.

[0095] Enter the buck resonant heating mode, keep K1 / K2 / K3 disconnected, keep Q7 / Q9 / Q11 turned on, Q8 / Q10 / Q12 disconnected, Q1 / Q3 / Q5 turned on and off at the same time, and turned on complementary with Q2 / Q4 / Q6, and control the action of Q1 / Q3 / Q5 through the duty cycle signal of open-loop table lookup or closed-loop control, precharge capacitor C2 to the target DC voltage and maintain it. The AC component target value of the heating current is given by the table lookup according to the real-time demand of the battery, and the error is subtracted from the neutral point current collected in real time by the current sensor. The error is output as the AC duty cycle through the multi-order quasi-proportional resonant controller and superimposed with the DC duty cycle signal. The superimposed duty cycle signal is modulated and controlled by Q1 / Q3 / Q5 to generate a high-frequency sinusoidal AC heating current with the target amplitude / frequency required by the battery in real time.

[0096] Driving scenario: K1 and K2 are disconnected, K3 is closed, and the dual inverters jointly modulate the reference voltage vector in the driving mode through vector linear synthesis to realize the driving mode.

[0097] The above implementation is only Figure 1 The control strategy of the topology of the vehicle's energy conversion system is shown in Figure 2-10 As shown, the present invention also discloses the topological structure of the energy conversion system of multiple vehicles, based on Figure 1-10 The topology of the energy conversion system of the vehicle, Table 1 records the different control strategies of each topology in the charging and discharging mode and the heating mode:

[0098] Table 1

[0099]

[0100]

[0101]

[0102] According to another embodiment of the present invention, a vehicle charging and discharging control method is provided, and the control method is applied to the energy conversion system of the vehicle in any of the above embodiments, such as Fig.11 As shown, the method includes:

[0103] Step S10, after detecting that the charging and discharging gun is inserted, obtaining charging and discharging data.

[0104] In this step, the charge and discharge data includes at least one of a charge and discharge message, a voltage level of an external device detected by a voltage detection device, and a charge and discharge capability of the battery.

[0105] Step S20, selecting a corresponding charge and discharge mode according to the charge and discharge data. The charge and discharge modes include: boost charge mode, buck charge mode, boost discharge, buck discharge, direct charge, and direct discharge.

[0106] Step S30 , controlling the operation of the vehicle's energy conversion system based on the selected charging and discharging mode.

[0107] In this step, the operation mode of the vehicle's energy conversion system is the boost charging mode, buck charging mode, boost discharge mode, buck discharge mode, direct charging mode, and direct discharge mode recorded in any of the above-mentioned embodiments, which will not be repeated here.

[0108] In a specific embodiment, Fig.12 The vehicle charging and discharging control method shown in FIG. Figure 1 The energy conversion system of the vehicle shown in FIG. 1 , the charging and discharging control method of the vehicle is as follows:

[0109] Through the message or voltage detection device, the voltage polarity and charging and discharging requirements of the external device are judged, and combined with the real-time charging and discharging capabilities of the battery, one of the six modes of boost charging, buck charging, boost discharging, buck discharging, direct charging, and direct discharging is determined;

[0110] Entering the boost charging or buck discharging mode, the charging and discharging capacitor C2 (i.e., the second capacitor) is pre-charged to the target voltage by controlling the two sets of inverter bridge arm switches, and then K1 and K2 are closed, and K3 is kept disconnected. After entering the boost charging process, Q7 / Q9 / Q11 (i.e., the upper bridge of the auxiliary inverter) is kept turned on, and Q8 / Q10 / Q12 (i.e., the lower bridge of the auxiliary inverter) is disconnected. The boost charging of the battery is achieved by controlling Q1 / Q2 / Q3 / Q4 / Q5 / Q6 (i.e., the main inverter bridge arm switches).

[0111] Entering the buck charging or boost discharging mode, the charging and discharging capacitor C2 is pre-charged to the target voltage by controlling the two sets of inverter bridge arm switches, and then K1 and K2 are closed, and K3 is kept disconnected. After entering the boost charging process, Q1 / Q3 / Q5 (i.e., the upper bridge of the main inverter) is kept turned on, and Q2 / Q4 / Q6 (i.e., the lower bridge of the main inverter) is disconnected. The buck charging of the battery is achieved by controlling Q7 / Q8 / Q9 / Q10 / Q11 / Q12 (i.e., the auxiliary inverter bridge arm switches).

[0112] To enter the direct charge and discharge mode, close K1, K2, and K3.

[0113] The above specific implementation is applied to Figure 1 The vehicle charging and discharging control method of the vehicle energy conversion system shown in the figure Figure 2-10 The vehicle charging and discharging control method of the vehicle energy conversion system is detailed in Table 1 and will not be repeated here.

[0114] According to another embodiment of the present invention, a vehicle battery heating control method is provided, and the control method is applied to the energy conversion system of the vehicle in any of the above embodiments, such as Fig.13 As shown, the method includes:

[0115] Step S100, obtaining heating data of the vehicle battery.

[0116] In this step, the charge and discharge data includes battery heating requirement data and / or component stress.

[0117] Step S200, selecting a corresponding heating mode according to the heating data. The heating modes include pulse heating and resonant heating, wherein the resonant heating mode includes a boost resonant heating mode and a buck resonant heating mode.

[0118] Step S300, controlling the operation of the vehicle's energy conversion system based on the selected charging and discharging mode.

[0119] In this step, the operation mode of the vehicle's energy conversion system is the same as the pulse heating, boost resonant heating mode and buck resonant heating mode described in any of the above embodiments, which will not be repeated here.

[0120] In a specific embodiment, Fig.14 The battery heating control method of the vehicle shown is applied as follows Figure 1 The energy conversion system of the vehicle shown in the figure, the battery heating control method of the vehicle is as follows:

[0121] According to the battery heating demand and component stress, one of the three modes of inductive pulse heating, boost resonant heating and buck resonant heating is determined.

[0122] Enter the inductive pulse heating mode, keep K1 / K2 open, close K3, and control Q1 / Q3 / Q5 / Q8 / Q10 / Q12 (i.e. the upper bridge of the main inverter and the lower bridge of the auxiliary inverter) to be turned on and off at the same time through the duty cycle signal of open-loop table lookup or closed-loop control, and complement with Q2 / Q4 / Q6 / Q7 / Q9 / Q11 (i.e. the lower bridge of the main inverter and the upper bridge of the auxiliary inverter) to generate a high-frequency pulse current with the target amplitude / frequency required by the battery in real time to heat the battery.

[0123] Enter the boost resonant heating mode, keep K1 / K2 / K3 disconnected, keep Q1 / Q3 / Q5 (i.e. the upper bridge of the main inverter) turned on, Q2 / Q4 / Q6 (i.e. the lower bridge of the main inverter) disconnected, Q7 / Q9 / Q11 (i.e. the upper bridge of the auxiliary inverter) turned on and off at the same time, and complemented with Q8 / Q10 / Q12 (i.e. the lower bridge of the auxiliary inverter) turned on, and the duty cycle signal of the open-loop table lookup or closed-loop control controls the action of Q7 / Q9 / Q11 to precharge the capacitor C2 to the target DC voltage and maintain it. The AC component target value of the heating current is given by the table lookup according to the real-time demand of the battery, and the error is subtracted from the neutral point current collected in real time by the current sensor. The error is output through the multi-order quasi-proportional resonant controller to output the AC duty cycle, which is superimposed with the DC duty cycle signal. The superimposed duty cycle signal is modulated and controlled by controlling the action of Q7 / Q9 / Q11 to generate a high-frequency sinusoidal AC heating current with the target amplitude / frequency required by the battery in real time to flow through the battery.

[0124] Enter the buck resonant heating mode, keep K1 / K2 / K3 disconnected, keep Q7 / Q9 / Q11 (i.e. the upper bridge of the auxiliary inverter) turned on, Q8 / Q10 / Q12 (i.e. the lower bridge of the auxiliary inverter) disconnected, Q1 / Q3 / Q5 (i.e. the upper bridge of the main inverter) turned on and off at the same time, and complemented with Q2 / Q4 / Q6 (i.e. the lower bridge of the main inverter) turned on, and the duty cycle signal of the open-loop table lookup or closed-loop control controls the action of Q1 / Q3 / Q5 to precharge the capacitor C2 to the target DC voltage and maintain it. The AC component target value of the heating current is given by the table lookup according to the real-time demand of the battery, and the error is subtracted from the neutral point current collected in real time by the current sensor. The error is output through the multi-order quasi-proportional resonant controller to output the AC duty cycle, which is superimposed with the DC duty cycle signal. The superimposed duty cycle signal is modulated and controlled by controlling the action of Q1 / Q3 / Q5 to generate a high-frequency sinusoidal AC heating current with the target amplitude / frequency required by the battery in real time to flow through the battery.

[0125] The above specific implementation is applied to Figure 1 The battery heating control method of the vehicle with the energy conversion system of the vehicle shown in the figure is Figure 2-10 The battery heating control method of the vehicle energy conversion system of the vehicle is detailed in Table 1 and will not be described in detail here.

[0126] According to another embodiment of the present invention, a vehicle is provided, comprising the AC energy conversion system for a vehicle as described in any one of the above embodiments.

[0127] According to another embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle charging and discharging control method in any of the above-mentioned embodiments can be implemented.

[0128] According to another embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle battery heating control method in any of the above-mentioned embodiments can be implemented.

[0129] According to another embodiment of the present invention, a readable storage medium is provided for storing a computer program, wherein the program, when executed by a computer or a processor, implements the steps of the vehicle charging and discharging control method in any of the above-mentioned embodiments.

[0130] According to another embodiment of the present invention, a readable storage medium is provided for storing a computer program, wherein when the program is executed by a computer or a processor, the program implements the steps of the vehicle battery heating control method in any of the above embodiments.

[0131] The energy conversion system of the vehicle of the present invention reuses the electric drive system of the vehicle, and can realize any one of the four modes of boost charging, buck charging, boost discharge and buck discharge when the vehicle battery is charged and discharged, and can meet the mutual compatibility and optimal power transmission between the vehicle battery and external devices of platforms with different voltage levels. When heating the vehicle battery, it can directly generate high-frequency current to form internal resistance heating of the battery, directly heat the battery, and the heating speed is greatly improved, which greatly improves the heating efficiency, and does not need to rely on the cooling circuit.

[0132] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A vehicle energy conversion system, characterized in that: include: Two sets of multi-phase inverters, at least one set of multi-phase windings, a first capacitor, a second capacitor and a controller of a vehicle electric drive system; The busbars of the first group of multi-phase inverters are connected in parallel with the battery of the vehicle and the first capacitor, the busbars of the second group of multi-phase inverters are connected in parallel with the second capacitor and an external device, and the busbars of the second group of multi-phase inverters are connected to the external device in an on-off manner through a first switch, at least one pole of the busbars of the first group of multi-phase inverters and the second group of multi-phase inverters are connected to each other, and at least one group of multi-phase windings are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters; one pole between the battery and the external device is directly connected in an on-off manner through a second switch; The controller is connected to the first switch, the second switch and the two groups of multi-phase inverters to control the on and off of the first switch and the second switch and drive the two groups of multi-phase inverters to operate, so as to realize the boost / bump charging and discharging of the vehicle or the battery heating of the vehicle.

2. The energy conversion system for a vehicle according to claim 1, characterized in that: The multi-phase winding is a group of multi-phase windings with an open neutral point, and two ends of the multi-phase winding are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters.

3. The energy conversion system for a vehicle according to claim 1, characterized in that: There are two groups of multi-phase windings, one ends of the two groups of multi-phase windings are connected to each other through a neutral point, and the other ends of the two groups of multi-phase windings are respectively connected to the midpoints of the bridge arms of the two groups of multi-phase inverters.

4. The energy conversion system for a vehicle according to any one of claims 1 to 3, characterized in that: The first busbar of the first group of multi-phase inverters is directly connected to the first busbar of the second group of multi-phase inverters; The second busbars of the first group of multi-phase inverters are not connected to the second busbars of the second group of multi-phase inverters, or The second busbars of the first group of multi-phase inverters are connected to the second busbars of the second group of multi-phase inverters in an on-off manner through a third switch.

5. The energy conversion system for a vehicle according to claim 1, characterized in that: The first busbar of the multi-phase inverters of the first group is directly connected to the first busbar of the multi-phase inverters of the second group, and the second busbar of the multi-phase inverters of the first group is not connected to the second busbar of the multi-phase inverters of the second group; There are two groups of multi-phase windings, one end of the first group of multi-phase windings is respectively connected to the midpoint of the bridge arm of the first group of multi-phase inverters, and the neutral point of the first group of multi-phase windings can be connected to the second bus of the second group of multi-phase inverters through a fourth switch, and one end of the second group of multi-phase windings is respectively connected to the midpoint of the bridge arm of the second group of multi-phase inverters, and the neutral point of the second group of multi-phase windings can be connected to the second bus of the first group of multi-phase inverters through a fifth switch.

6. The AC energy conversion system for a vehicle according to claim 1, characterized in that: The power conversion of step-up or step-down is performed between the battery and the energy storage device to generate a high-frequency alternating current to pass through the battery, and the battery is heated by the thermal effect of the current.

7. The AC energy conversion system for a vehicle according to claim 6, characterized in that: The controller controls the bridge arm switches of the two groups of the multi-phase inverters to operate synchronously to generate the high-frequency alternating current with variable amplitude and frequency.

8. A method for controlling charging and discharging of a vehicle, characterized in that: The energy conversion system for a vehicle according to any one of claims 1 to 7, the method comprising: After detecting that the charging and discharging gun is inserted, the charging and discharging data is obtained; Selecting a corresponding charging and discharging mode according to the charging and discharging data, wherein the charging and discharging mode includes: a boost charging mode, a buck charging mode, a boost discharging mode, a buck discharging mode, a direct charging mode, and a direct discharging mode; The operation of the vehicle's energy conversion system is controlled based on the selected charging and discharging mode.

9. A vehicle battery heating control method, characterized in that: The energy conversion system for a vehicle according to any one of claims 1 to 7, the method comprising: Obtain heating data of vehicle battery; Selecting a corresponding heating mode according to the heating data, the heating mode including a pulse heating mode and a resonance heating mode; Operation of an energy conversion system of the vehicle is controlled based on the selected heating mode.

10. A vehicle, characterized in that: An energy conversion system for a vehicle comprising any one of claims 1-7.

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