Battery heating system for vehicle, battery heating control method for vehicle, and vehicle

Abstract

The invention provides a battery heating system of a vehicle, a control method and the vehicle. The system comprises a multi-phase inverter, a multi-phase winding, an energy storage device and a controller. Wherein a bus of the multi-phase inverter is correspondingly connected to a bus of a vehicle battery, one end of the multi-phase winding is correspondingly connected to a bridge arm of the multi-phase inverter, a neutral point of the multi-phase winding is connected to one of the buses of the battery, the energy storage device is connected to the battery, and the controller is connected to the multi-phase inverter; the controller is configured to determine a direct current duty ratio signal and an alternating current duty ratio signal according to the real-time heating requirement of the battery, and control the action of a bridge arm of the multi-phase inverter based on the direct current duty ratio signal and the alternating current duty ratio signal. And heating the battery by using the target alternating current corresponding to the real-time heating requirement of the battery formed at the neutral point of the multi-phase winding. The DC duty ratio signal and the AC duty ratio signal jointly control the action of the multi-phase inverter, so that the battery can be heated through the modulatable duty ratio signal.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to a battery heating system of a vehicle, a battery heating control method of a vehicle, and a vehicle. Background Art

[0002] In the field of new energy vehicles, low temperature will deteriorate battery performance and reduce battery power output. Charging at low temperature will increase the possibility of lithium deposition in the power battery anode, affecting battery capacity and safety. Preheating is the mainstream solution. The external heating solution currently used more often uses a medium as an intermediate link to transfer heat, which has low efficiency, poor heating uniformity, and a long heating time. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a battery heating system for a vehicle, a battery heating control method for a vehicle and a vehicle, which jointly control the action of a multi-phase inverter through a DC duty cycle signal and an AC duty cycle signal, so as to achieve battery heating through an adjustable duty cycle signal, thereby meeting the battery heating requirements under different working conditions.

[0004] In order to solve or improve the above technical problems to a certain extent, according to one aspect of the present invention, a battery heating system for a vehicle is provided, comprising: a multi-phase inverter, a multi-phase winding, an energy storage device and a controller;

[0005] The busbar of the multi-phase inverter is connected to the busbar of the vehicle battery, one end of the multi-phase winding is connected to the bridge arm of the multi-phase inverter, the neutral point of the multi-phase winding is connected to one of the busbars of the battery, the energy storage device is connected to the battery, and the controller is connected to the multi-phase inverter;

[0006] The controller is configured to determine a DC duty cycle signal and an AC duty cycle signal according to a real-time heating demand of the battery, and control the bridge arm action of the multi-phase inverter based on the DC duty cycle signal and the AC duty cycle signal to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding to heat the battery.

[0007] In some embodiments, the controller is configured to control the bridge arm action of the multi-phase inverter based on the DC duty cycle signal so that the energy storage device is charged to a target voltage, adjust the AC duty cycle signal based on the neutral point current of the multi-phase winding, and control the bridge arm action of the multi-phase inverter according to the superimposed DC duty cycle signal and the AC duty cycle signal to form the target AC current to heat the battery.

[0008] In some embodiments, the controller is configured to adjust the AC duty cycle signal according to a difference between the neutral point current and the target AC current.

[0009] In some implementations, the controller is configured to adjust the DC duty cycle signal according to a difference between a current voltage of the energy storage device and the target voltage.

[0010] In some embodiments, a correspondence between a battery heating requirement and a preset DC duty cycle signal and a preset AC duty cycle signal is pre-stored, and the controller is configured to determine the DC duty cycle signal and the AC duty cycle signal based on the correspondence and the real-time heating requirement of the battery.

[0011] In some embodiments, the energy storage device is connected in parallel to the busbar of the multi-phase inverter and the busbar of the battery, and the neutral point of the multi-phase winding is directly connected to any pole of the busbar of the battery; or

[0012] One end of the energy storage device is connected to the neutral point of the multi-phase winding, and the other end of the energy storage device is connected to any pole of the busbar of the multi-phase inverter.

[0013] In some embodiments, the multi-phase inverter, the multi-phase winding, and the energy storage device are reused as an electric drive system of a vehicle.

[0014] In some implementations, during the battery heating process, the controller controls the multi-phase bridge arms of the multi-phase inverter to operate synchronously to eliminate torque generated when current flows through the multi-phase windings.

[0015] According to an embodiment of the present invention, a battery heating control method for a vehicle is provided, which is applied to the battery heating system of the vehicle described in any one of the above embodiments, and the method includes:

[0016] Determining a DC duty cycle signal and an AC duty cycle signal according to a real-time heating demand of the battery;

[0017] The bridge arm action of the multi-phase inverter is controlled based on the DC duty cycle signal and the AC duty cycle signal, so as to form an AC current required for the actual heating demand of the battery at the neutral point of the multi-phase winding to heat the battery.

[0018] According to an embodiment of the present invention, a vehicle is provided, comprising the battery heating system for the vehicle described in any one of the above embodiments.

[0019] 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.

[0020] 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.

[0021] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the vehicle battery heating system, vehicle battery heating control method and vehicle of the present invention can achieve considerable technical advancement and practicality, and have wide industrial utilization value, and have at least the following advantages:

[0022] The vehicle battery heating system, vehicle battery heating control method and battery of the present invention can directly generate high-frequency current to flow through the internal resistance of the battery during the battery heating process, generate heat inside the battery to directly heat the battery, effectively improve the efficiency of battery heating, and do not rely on a cooling circuit. At the same time, by modulating the duty cycle signal to achieve real-time variable current frequency or amplitude, it can adapt to battery usage requirements under different working conditions. And in the process of heating the battery, the multi-phase bridge arms of the multi-phase inverter are controlled to move synchronously to ensure that the currents of the multi-phase windings are the same in real time, completely eliminating the torque generated by the electric drive system during the battery heating process, and avoiding the NVH problem of the vehicle caused by the low-order pulse torque brought by the reuse of the electric drive system to heat the battery.

[0023] 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

[0024] Figure 1 A topological diagram of a battery heating system for a vehicle according to a first embodiment of the present invention;

[0025] Figure 2 A topological diagram of a battery heating system for a vehicle according to a second embodiment of the present invention;

[0026] Figure 3 A topological diagram of a battery heating system for a vehicle according to a third embodiment of the present invention;

[0027] Figure 4 A topological diagram of a battery heating system for a vehicle according to a fourth embodiment of the present invention;

[0028] Figure 5 A heating control block diagram of a battery heating system for a vehicle according to an embodiment of the present invention;

[0029] Figure 6 A heating control block diagram of a battery heating system for a vehicle according to another embodiment of the present invention;

[0030] Figure 7 A heating control block diagram of a battery heating system for a vehicle according to another embodiment of the present invention;

[0031] Figure 8 The figure is a flow chart of a method for controlling battery heating of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the battery heating system of the vehicle, the battery heating control method of the vehicle and the specific implementation mode and effects of the vehicle proposed in accordance with the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0033] Figure 1-4 FIG. 2 shows a schematic diagram of the topological structure of the battery heating system of a vehicle of the present invention. Figure 1-4 As shown, the battery heating system of the vehicle includes a multi-phase inverter 10, a multi-phase winding 20, an energy storage device 30 and a controller (not shown in the figure).

[0034] The multi-phase inverter 10 , the multi-phase winding 20 and the energy storage device 30 are connected to the battery of the vehicle, and the controller is connected to the multi-phase inverter 10 .

[0035] In one embodiment, the busbar of the multi-phase inverter 10 of the battery heating system of the vehicle is correspondingly connected to the busbar of the battery, the multi-phase incoming terminals of the multi-phase winding 20 are respectively correspondingly connected to the midpoints of the multi-phase bridge arms of the multi-phase inverter 10, the neutral point of the multi-phase winding 20 is directly connected to any pole (positive or negative) of the battery busbar, and the energy storage device 30 is connected in parallel to the busbar of the multi-phase inverter 10 and the busbar of the battery.

[0036] In one embodiment, the multi-phase inverter 10, the multi-phase winding 20 and the energy storage device 30 of the battery heating system of the vehicle are reused from the electric drive system of the vehicle. By reusing the electric drive system of the vehicle to heat the battery of the vehicle, the assembly cost and body volume of the vehicle can be reduced, and there is no need to improve the existing DC charging device, which greatly reduces the configuration cost.

[0037] In this embodiment, the busbar of the multi-phase inverter 10 and the busbar of the battery can be connected on and off by setting a switch, and the neutral point of the multi-phase winding 20 and the battery busbar can be connected on and off by setting a switch, so that when the battery heating system of the vehicle reuses the electric drive system of the vehicle, the reused electric drive system of the vehicle can be controlled by the switch to switch between heating the battery of the vehicle and driving the vehicle normally.

[0038] In some specific embodiments, Figure 1 and Figure 2 As shown, the battery heating system of the vehicle includes a three-phase inverter 100 , a three-phase winding 200 , a first capacitor C1 and a controller (not shown in the figure). In these specific embodiments, the first capacitor C1 serves as the energy storage device 30 .

[0039] Among them, the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 are the inverter, winding and capacitor of the electric drive system of the reused vehicle. The three-phase inverter 100 includes three-phase bridge arms A, B and C, wherein the A-phase bridge arm includes switching devices Q1 and Q2, the B-phase bridge arm includes switching devices Q3 and Q4, and the C-phase bridge arm includes switching devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB and a C-phase winding LC.

[0040] like Figure 1 and Figure 2 As shown, the windings LA, LB and LC of the three-phase winding 200 are respectively connected to the midpoints of the three-phase bridge arms A, B and C of the three-phase inverter 100 through the three-phase incoming line terminals. The first capacitor C1 is connected in parallel to the busbar of the battery and the busbar of the three-phase winding 200. The positive electrode of the busbar of the three-phase inverter 100 is connected to the positive electrode of the busbar of the battery through the first switch K1, and the negative electrode of the busbar of the three-phase inverter 100 is connected to the negative electrode of the busbar of the battery through the second switch K2.

[0041] Alternatively, if Figure 1 As shown, the neutral point of the three-phase winding 200 is connected to the positive electrode of the busbar of the battery through the third switch K3. Figure 2 As shown, the neutral point of the three-phase winding 200 is connected to the negative pole of the busbar of the battery through the third switch K3 in a switchable manner.

[0042] In these embodiments, when the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 of the reused electric drive system need to perform the battery heating function, the second switch K2 and the third switch K3 are closed, and the first switch K1 is opened; when the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 need to perform the vehicle driving function, the first switch K1 and the second switch K2 are closed, and the third switch K3 is opened.

[0043] Of course, the above Figure 1 and Figure 2 What is shown are only some specific implementation methods. The multi-phase inverter 10 and the multi-phase winding 20 of the present invention are not just three-phase. The phase numbers of the multi-inverter and the winding can be configured accordingly according to actual use requirements. The present invention is not limited to the specific phase numbers of the inverter and the winding.

[0044] In one embodiment, the busbar of the multi-phase inverter 10 is correspondingly connected to the busbar of the battery, and the multi-phase incoming line ends of the multi-phase winding 20 are respectively correspondingly connected to the midpoints of the multi-phase bridge arms of the multi-phase inverter 10; one end of the energy storage device 30 is connected to the neutral point of the multi-phase winding 20, and the other end of the energy storage device 30 is connected to any pole (positive or negative) of the busbar of the multi-phase inverter 10, and the controller is connected to the multi-phase inverter 10.

[0045] In some specific embodiments, Figure 3 and Figure 4 As shown, the battery heating system of the vehicle includes a three-phase inverter 100 , a three-phase winding 200 , a first capacitor C1 , a second capacitor C2 and a controller (not shown in the figure). In these embodiments, the second capacitor C2 serves as the energy storage device 30 .

[0046] Among them, the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 are the inverter, winding and capacitor of the electric drive system of the reused vehicle. The three-phase inverter 100 includes three-phase bridge arms A, B and C, wherein the A-phase bridge arm includes switching devices Q1 and Q2, the B-phase bridge arm includes switching devices Q3 and Q4, and the C-phase bridge arm includes switching devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB and a C-phase winding LC.

[0047] like Figure 1 and Figure 2 As shown, the windings LA, LB and LC of the three-phase winding 200 are respectively connected to the midpoints of the three-phase bridge arms A, B and C of the three-phase inverter 100 through the three-phase incoming line terminals. The first capacitor C1 is connected in parallel to the busbar of the battery and the busbar of the three-phase winding 200. The positive electrode of the busbar of the three-phase inverter 100 is connected to the positive electrode of the busbar of the battery through the first switch K1, and the negative electrode of the busbar of the three-phase inverter 100 is connected to the negative electrode of the busbar of the battery through the second switch K2.

[0048] Alternatively, if Figure 3 As shown, one end of the second capacitor C2 is connected to the neutral point of the three-phase winding 200 through the fourth switch K4, and the other end of the second capacitor C2 is connected to the negative electrode of the bus of the three-phase inverter 100; Figure 4 As shown, one end of the second capacitor C2 is connected to the neutral point of the three-phase winding 200 through the fourth switch K4, and the other end of the second capacitor C2 is connected to the positive electrode of the busbar of the three-phase inverter 100.

[0049] In these embodiments, when the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 of the reused electric drive system need to perform the battery heating function, the first switch K1, the second switch K2 and the fourth switch K4 are closed; when the three-phase inverter 100, the three-phase winding 200 and the first capacitor C1 need to perform the vehicle driving function, the first switch K1 and the second switch K2 are closed, and the fourth switch K4 is opened.

[0050] Of course, the above Figure 3 and Figure 4 What is shown are only some specific implementation methods. The multi-phase inverter 10 and the multi-phase winding 20 of the present invention are not just three-phase. The phase numbers of the multi-inverter and the winding can be configured accordingly according to actual use requirements. The present invention is not limited to the specific phase numbers of the inverter and the winding.

[0051] The controller of the vehicle's battery heating system is configured to determine a DC duty cycle signal and an AC duty cycle signal according to the real-time heating demand of the battery, and jointly control the bridge arm action of the multi-phase inverter 10 based on the determined DC duty cycle signal and AC duty cycle signal to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding 20. When the formed target AC current flows through the battery, the battery is heated by the heat generated by the internal resistance of the battery.

[0052] The present invention effectively improves the heating efficiency of the battery by forming an alternating current to heat the battery, and the battery heating can be achieved without configuring a cooling circuit.

[0053] In one embodiment, the controller is configured to control the bridge arm action of the multi-phase inverter 10 based on the DC duty cycle signal, charge the energy storage device 30 so that the energy storage device 30 is charged to the target voltage, adjust the AC duty cycle signal based on the neutral point current of the multi-phase winding 20, and control the bridge arm action of the multi-phase inverter 10 according to the superimposed DC duty cycle signal and the AC duty cycle signal, so as to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding 20, so as to heat the battery through the formed target AC current.

[0054] The target voltage is preset according to actual usage requirements.

[0055] Optionally, in actual application, the DC duty cycle signal is adjusted according to the difference between the current voltage of the energy storage device 30 and the target voltage, thereby realizing closed-loop control of charging the energy storage device 30. After the energy storage device 30 is controlled to charge to the target voltage, the voltage of the energy storage device 30 needs to be maintained at the target voltage.

[0056] The controller obtains the neutral point current of the multi-phase winding 20 collected by the current sensor, and compares the neutral point current with a preset target AC current to determine the difference between the neutral point current and the target AC current, and then adjusts the AC duty cycle signal according to the difference between the neutral point current and the target AC current.

[0057] The target AC current can be determined by looking up a table according to the real-time heating requirement of the battery, that is, the corresponding relationship between the heating requirement of the battery and the target AC current is pre-stored, and the corresponding relationship can be determined in advance by experiments, but the present invention is not limited thereto.

[0058] The controller superimposes the DC duty cycle signal with the adjusted AC duty cycle signal, and controls the operation of the multi-phase inverter 10 according to the superimposed duty cycle signal, thereby forming an AC current with an amplitude or frequency that meets the battery heating requirements between the energy storage device 30 and the battery, so that heat is generated to heat the battery after the AC current flows through the internal resistance of the battery.

[0059] In one embodiment, a correspondence between the heating requirement of the battery and a preset DC duty cycle signal and a preset AC duty cycle signal is pre-stored, and the correspondence is pre-determined through experiments.

[0060] In this embodiment, the controller is configured to determine the DC duty cycle signal and AC duty cycle signal corresponding to the real-time heating demand of the battery in the correspondence relationship between the pre-stored battery heating demand and the preset DC duty cycle signal and the preset AC duty cycle signal based on the acquired real-time heating demand of the battery, and control the bridge arm action of the multi-phase inverter 10 according to the determined DC duty cycle signal and AC duty cycle signal, so as to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding 20, so as to heat the battery through the formed target AC current. In one embodiment, in the process of heating the battery by the battery heating system of the vehicle, the controller controls the multi-phase bridge arm of the multi-phase inverter 10 to act synchronously to ensure that the current of the multi-phase winding 20 is the same in real time, completely eliminating the torque generated by the electric drive system during the battery heating process, and avoiding the NVH problem of the vehicle caused by the low-order pulse torque brought by the multiplexing electric drive system to heat the battery.

[0061] In a specific embodiment, the application Figure 1 and Figure 2 The battery heating system of the vehicle shown in the figure, during the heating process of the battery of the vehicle, Figure 5As shown, firstly, the required target AC current i* is determined based on the real-time heating demand of the battery, and the controller determines the corresponding DC duty cycle signal and AC duty cycle signal based on the target AC current i*. Based on the determined DC duty cycle signal and AC duty cycle signal, a sinusoidal pulse width modulation technology (i.e., SPWM, Sinusoidal Pulse Width Modulation) is used to control the bridge arm action of the three-phase inverter 100 to generate an AC current at the neutral point of the three-phase winding 200 and charge the first capacitor C1.

[0062] The obtained DC voltage of the first capacitor C1 (i.e., the current voltage of the energy storage device 30, which is the average voltage within a preset period) is compared with the target voltage of the first capacitor C1 through a comparator, and the difference between the two is calculated. The controller PI adjusts the DC duty cycle signal according to the difference between the DC voltage of the first capacitor C1 and the target voltage. The controller controls the bridge arm action of the three-phase inverter 100 based on the adjusted DC duty cycle signal Ddc* to charge the first capacitor C1 to the target voltage and maintain the target voltage.

[0063] Then, according to the real-time heating demand of the battery, the target AC current i* is determined by looking up the table, and the current current i_fb (i.e., the neutral point current) of the neutral point of the three-phase winding 200 detected by the current sensor is obtained. The difference between the target AC current I* and the current current i_fb of the neutral point is determined by the comparator, and the multi-order quasi-proportional resonant controller (i.e., multi-order QPR) adjusts the AC duty cycle signal according to the difference between the target AC current I* and the current current i_fb of the neutral point to form an adjusted duty cycle signal Dac*.

[0064] Optionally, the AC duty cycle signal can be adjusted by a multi-order quasi-proportional resonant controller (ie, multi-order QPR), or by other means, such as a single-order quasi-proportional resonant controller, but the present invention is not limited thereto.

[0065] The adjusted AC duty cycle signal Dac* is superimposed on the DC duty cycle signal Ddc*, and the controller uses sinusoidal pulse width modulation technology to control the bridge arm action of the three-phase inverter 100 according to the superimposed duty cycle signal to generate a target AC current of the amplitude or frequency required for battery heating in real time, and after the target AC current flows through the internal resistance of the battery, heat is generated to heat the battery.

[0066] Specifically, in applications such as Figure 1In the battery heating system of the vehicle shown, the controller controls the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) to be turned on and off synchronously based on the superimposed duty cycle signal. At this time, the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) will be turned on complementarily with the upper bridge arm of the three-phase inverter 100 (i.e., when the upper bridge arm is turned on, the lower bridge arm is disconnected; when the upper bridge arm is disconnected, the lower bridge arm is turned on).

[0067] In application such as Figure 2 In the battery heating system of the vehicle shown, the controller controls the synchronous on and off of the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) based on the superimposed duty cycle signal. At this time, the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) will be complementary to the upper bridge arm of the three-phase inverter 100 (i.e., when the lower bridge arm is turned on, the upper bridge arm is disconnected; when the lower bridge arm is disconnected, the upper bridge arm is turned on).

[0068] In a specific embodiment, the application Figure 3 and Figure 4 The battery heating system of the vehicle shown in the figure, during the heating process of the battery of the vehicle, Figure 6 As shown, firstly, the required target AC current i* is determined based on the real-time heating demand of the battery, and the controller determines the corresponding DC duty cycle signal and AC duty cycle signal based on the target AC current i*. Based on the determined DC duty cycle signal and AC duty cycle signal, a sinusoidal pulse width modulation technology (i.e., SPWM, Sinusoidal Pulse Width Modulation) is used to control the bridge arm action of the three-phase inverter 100 to generate an AC current at the neutral point of the three-phase winding 200 and charge the second capacitor C2.

[0069] The obtained DC voltage of the second capacitor C2 (i.e., the current voltage of the energy storage device 30, which is the average voltage within a preset period) is compared with the target voltage of the second capacitor C2 through a comparator, and the difference between the two is calculated. The controller PI adjusts the DC duty cycle signal according to the difference between the DC voltage of the second capacitor C2 and the target voltage. The controller controls the bridge arm action of the three-phase inverter 100 based on the adjusted DC duty cycle signal Ddc* to charge the second capacitor C2 to the target voltage and maintain the target voltage.

[0070] Then, according to the real-time heating demand of the battery, the target AC current i* is determined by looking up the table, the current current i_fb (i.e., the neutral point current) of the neutral point of the three-phase winding 200 detected by the current sensor is obtained, and the difference between the target AC current I* and the current current i_fb of the neutral point is determined by the comparator. The multi-order quasi-proportional resonant controller (i.e., multi-order QPR) adjusts the AC duty cycle signal according to the difference between the target AC current I* and the current current i_fb of the neutral point to form an adjusted duty cycle signal Dac*.

[0071] Optionally, the AC duty cycle signal can be adjusted by a multi-order quasi-proportional resonant controller (ie, multi-order QPR), or by other means, such as a single-order quasi-proportional resonant controller, but the present invention is not limited thereto.

[0072] The adjusted AC duty cycle signal Dac* is superimposed on the DC duty cycle signal Ddc*, and the controller uses sinusoidal pulse width modulation technology to control the bridge arm action of the three-phase inverter 100 according to the superimposed duty cycle signal to generate a target AC current of the amplitude or frequency required for battery heating in real time, and after the target AC current flows through the internal resistance of the battery, heat is generated to heat the battery.

[0073] Specifically, in applications such as Figure 3 In the battery heating system of the vehicle shown, the controller controls the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) to be turned on and off synchronously based on the superimposed duty cycle signal. At this time, the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) will be turned on complementarily with the upper bridge arm of the three-phase inverter 100 (i.e., when the upper bridge arm is turned on, the lower bridge arm is disconnected; when the upper bridge arm is disconnected, the lower bridge arm is turned on).

[0074] In application such as Figure 4 In the battery heating system of the vehicle shown, the controller controls the synchronous on and off of the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) based on the superimposed duty cycle signal. At this time, the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) will be complementary to the upper bridge arm of the three-phase inverter 100 (i.e., when the lower bridge arm is turned on, the upper bridge arm is disconnected; when the lower bridge arm is disconnected, the upper bridge arm is turned on).

[0075] In a specific embodiment, the application Figure 1-4 The battery heating system of the vehicle shown in the figure, during the heating process of the battery of the vehicle, Figure 7As shown, based on the real-time heating demand of the battery, the corresponding DC duty cycle signal Ddc and AC duty cycle signal Dac are determined, and the controller uses sinusoidal pulse width modulation technology to control the bridge arm action of the three-phase inverter 100 based on the DC duty cycle signal Ddc and the AC duty cycle signal Dac to generate an AC current at the neutral point of the three-phase winding 200, and the AC current formed at the neutral point of the three-phase winding 200 reaches the target AC current i* required for the real-time heating demand of the battery.

[0076] Specifically, in applications such as Figure 1 In the battery heating system of the vehicle shown, the controller controls the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) to be turned on and off synchronously based on the superimposed duty cycle signal. At this time, the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) will be turned on complementarily with the upper bridge arm of the three-phase inverter 100 (i.e., when the upper bridge arm is turned on, the lower bridge arm is disconnected; when the upper bridge arm is disconnected, the lower bridge arm is turned on).

[0077] In application such as Figure 2 In the battery heating system of the vehicle shown, the controller controls the synchronous on and off of the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) based on the superimposed duty cycle signal. At this time, the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) will be complementary to the upper bridge arm of the three-phase inverter 100 (i.e., when the lower bridge arm is turned on, the upper bridge arm is disconnected; when the lower bridge arm is disconnected, the upper bridge arm is turned on).

[0078] In application such as Figure 3 In the battery heating system of the vehicle shown, the controller controls the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) to be turned on and off synchronously based on the superimposed duty cycle signal. At this time, the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) will be turned on complementarily with the upper bridge arm of the three-phase inverter 100 (i.e., when the upper bridge arm is turned on, the lower bridge arm is disconnected; when the upper bridge arm is disconnected, the lower bridge arm is turned on).

[0079] In application such as Figure 4 In the battery heating system of the vehicle shown, the controller controls the synchronous on and off of the lower bridge arm of the three-phase inverter 100 (i.e., the switching devices Q2, Q4 and Q6) based on the superimposed duty cycle signal. At this time, the upper bridge arm of the three-phase inverter 100 (i.e., the switching devices Q1, Q3 and Q5) will be complementary to the upper bridge arm of the three-phase inverter 100 (i.e., when the lower bridge arm is turned on, the upper bridge arm is disconnected; when the lower bridge arm is disconnected, the upper bridge arm is turned on).

[0080] According to another embodiment of the present invention, a vehicle battery heating control method is provided. The control method is applied to the vehicle battery heating system of any of the above embodiments. Figure 7As shown, the method includes:

[0081] Step S10, determining a DC duty cycle signal and an AC duty cycle signal according to the real-time heating demand of the battery. The method of determining the DC duty cycle signal and the AC duty cycle signal has been described in detail in multiple embodiments or implementations of the battery heating system of the vehicle, and will not be repeated here.

[0082] Step S20, controlling the bridge arm action of the multi-phase inverter based on the DC duty cycle signal and the AC duty cycle signal to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding to heat the battery.

[0083] The method of controlling the bridge arm action of the multi-phase inverter based on the DC duty cycle signal and the AC duty cycle signal has been described in detail in multiple embodiments or implementations of the battery heating system of the vehicle and will not be repeated here.

[0084] According to another embodiment of the present invention, a vehicle is provided, comprising the battery heating system for the vehicle described in any one of the above embodiments.

[0085] 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.

[0086] 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.

[0087] The vehicle battery heating system, vehicle battery heating control method and battery of the present invention can directly generate high-frequency current to flow through the internal resistance of the battery during the battery heating process, generate heat inside the battery to directly heat the battery, effectively improve the efficiency of battery heating, and do not rely on a cooling circuit. At the same time, by modulating the duty cycle signal to achieve real-time variable current frequency or amplitude, it can adapt to battery usage requirements under different working conditions. And in the process of heating the battery, the multi-phase bridge arms of the multi-phase inverter are controlled to move synchronously to ensure that the currents of the multi-phase windings are the same in real time, completely eliminating the torque generated by the electric drive system during the battery heating process, and avoiding the NVH problem of the vehicle caused by the low-order pulse torque brought by the reuse of the electric drive system to heat the battery.

[0088] 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 battery heating system for a vehicle, characterized in that: include: Multiphase inverters, multiphase windings, energy storage devices and controllers; The busbar of the multi-phase inverter is connected to the busbar of the vehicle battery, one end of the multi-phase winding is connected to the bridge arm of the multi-phase inverter, the neutral point of the multi-phase winding is connected to one of the busbars of the battery, the energy storage device is connected to the battery, and the controller is connected to the multi-phase inverter; The controller is configured to determine a DC duty cycle signal and an AC duty cycle signal according to a real-time heating demand of the battery, and control the bridge arm action of the multi-phase inverter based on the DC duty cycle signal and the AC duty cycle signal to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding to heat the battery.

2. The battery heating system for a vehicle according to claim 1, characterized in that: The controller is configured to control the bridge arm action of the multi-phase inverter based on the DC duty cycle signal so that the energy storage device is charged to a target voltage, adjust the AC duty cycle signal based on the neutral point current of the multi-phase winding, and control the bridge arm action of the multi-phase inverter according to the superimposed DC duty cycle signal and the AC duty cycle signal to form the target AC current to heat the battery.

3. The battery heating system for a vehicle according to claim 2, characterized in that: The controller is configured to adjust the AC duty cycle signal according to a difference between the neutral point current and the target AC current.

4. The battery heating system for a vehicle according to claim 2, characterized in that: The controller is configured to adjust the DC duty cycle signal according to a difference between a current voltage of the energy storage device and the target voltage.

5. The battery heating system for a vehicle according to claim 1, characterized in that: A correspondence between the heating requirement of the battery and a preset DC duty cycle signal and a preset AC duty cycle signal is pre-stored, and the controller is configured to determine the DC duty cycle signal and the AC duty cycle signal based on the correspondence and the real-time heating requirement of the battery.

6. The battery heating system for a vehicle according to claim 1, characterized in that: The energy storage device is connected in parallel to the busbar of the multi-phase inverter and the busbar of the battery, and the neutral point of the multi-phase winding is directly connected to any pole of the busbar of the battery; or One end of the energy storage device is connected to the neutral point of the multi-phase winding, and the other end of the energy storage device is connected to any pole of the busbar of the multi-phase inverter.

7. The battery heating system for a vehicle according to claim 1, characterized in that: The multi-phase inverter, the multi-phase winding and the energy storage device are an electric drive system for a multiplexed vehicle.

8. The battery heating system for a vehicle according to claim 1, characterized in that: During the battery heating process, the controller controls the multi-phase bridge arms of the multi-phase inverter to act synchronously to eliminate the torque generated when current flows through the multi-phase windings.

9. A vehicle battery heating control method, characterized in that: A battery heating system for a vehicle according to any one of claims 1 to 8, the method comprising: Determining a DC duty cycle signal and an AC duty cycle signal according to a real-time heating demand of the battery; The bridge arm action of the multi-phase inverter is controlled based on the DC duty cycle signal and the AC duty cycle signal, so as to form a target AC current corresponding to the real-time heating demand of the battery at the neutral point of the multi-phase winding to heat the battery.

10. A vehicle, characterized in that: A battery heating system for a vehicle comprising any one of claims 1-8.

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