Battery heating control method, system and device, storage medium and program product

Abstract

The invention discloses a battery heating control method, system and device, a storage medium and a program product, the method is applied to a motor controller in the battery heating control system, the battery heating control system further comprises a first motor and a second motor, and the motor controller further comprises a first inverter corresponding to the first motor. The second inverter corresponds to the second motor; the method comprises the following steps: monitoring bridge arm conduction working conditions of a first inverter and a second inverter in response to a battery heating signal; a bridge arm PWM signal of the first inverter and / or the second inverter is adjusted based on a monitoring result, so that a current conduction path is formed among the first inverter, the second inverter and the vehicle battery, the battery is heated, the control timeliness between the two inverters in the double motors is ensured, the control stability is ensured, and the vehicle safety is improved. The heating effect of the battery driven by the double motors is effectively improved, the temperature rise rate of the battery is greatly improved, and the charging efficiency of the battery is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a battery heating control method, system, device, storage medium, and program product. Background Technology

[0002] The charging performance of power battery packs in new energy vehicles decreases at low temperatures. Under cold driving conditions, the battery pack needs to be preheated before it can be charged quickly. Currently, battery heating methods include indirect heating and direct heating. Direct heating involves flowing current through the battery pack, utilizing its internal resistance to generate heat.

[0003] When using dual electric drive assemblies in series for direct heating, each needs to independently control its switching transistors. Currently, microsecond-level timing synchronization is not possible, and there is no fast communication between the two electric controllers. Communication methods such as CAN and LIN can only achieve millisecond-level communication. Therefore, for direct heating in a dual electric drive assembly system, there is currently no high-speed communication to ensure the control timeliness of each inverter in the dual motors, resulting in poor performance of direct heating of the battery by dual motors and an inability to quickly preheat the battery. Summary of the Invention

[0004] The main objective of this invention is to provide a battery heating control method, system, device, storage medium, and program product, aiming to solve the technical problem that the existing technology cannot ensure control timeliness, resulting in poor effect of direct heating of the battery by dual motor drive and inability to quickly preheat the battery.

[0005] To achieve the above objectives, the present invention provides a battery heating control method. The method is applied to a motor controller in a battery heating control system. The battery heating control system further includes a first motor and a second motor. The motor controller further includes a first inverter corresponding to the first motor and a second inverter corresponding to the second motor. The battery heating control method includes:

[0006] In response to the battery heating signal, the conduction status of the bridge arms of the first inverter and the second inverter is monitored;

[0007] Based on the monitoring results, the PWM signal of the bridge arm of the first inverter and / or the second inverter is adjusted to form a current conduction path between the first inverter, the second inverter and the vehicle battery, thereby heating the battery.

[0008] Optionally, adjusting the bridge arm PWM signal of the first inverter and / or the second inverter based on the monitoring results includes:

[0009] Based on the monitoring results, obtain the inductor current data during the conduction process of the bridge arms of the first inverter and the second inverter;

[0010] The target turn-on time is determined based on the inductor current data. The target turn-on time is the moment when the rising edge of the bridge arm PWM signal of the first inverter and the falling edge of the bridge arm PWM signal of the second inverter occur simultaneously, or the moment when the falling edge of the bridge arm PWM signal of the first inverter and the rising edge of the bridge arm PWM signal of the second inverter occur simultaneously.

[0011] The PWM signals of the bridge arms of the first inverter and / or the second inverter are adjusted based on the target turn-on time.

[0012] Optionally, determining the target turn-on time based on the inductor current data includes:

[0013] The absolute value of the inductor current at each moment during the conduction process of the bridge arm is determined based on the inductor current data.

[0014] The maximum and minimum values ​​during the conduction process of the bridge arm are determined based on the absolute value of the inductor current.

[0015] The target conduction time is determined based on the maximum value time and the minimum value time.

[0016] Optionally, determining the target turn-on time based on the inductor current data includes:

[0017] Multiple initial conduction times are determined based on the inductor current data;

[0018] The target conduction time is obtained by aggregating the average values ​​of the multiple initial conduction times.

[0019] Optionally, monitoring the arm conduction status of the first inverter and the second inverter includes:

[0020] Obtain the first bridge arm PWM period of the first inverter and the second bridge arm PWM period of the second inverter;

[0021] Determine the least common multiple between the PWM periods of the first bridge arm and the PWM periods of the second bridge arm;

[0022] The traversal time is determined based on the least common multiple.

[0023] The bridge arm switching signals of the first inverter and the second inverter are scanned traversally according to the traversal duration to monitor the conduction status of the bridge arms of the first inverter and the second inverter.

[0024] Optionally, the first inverter includes a first upper bridge arm and a first lower bridge arm, and the second inverter includes a second upper bridge arm and a second lower bridge arm.

[0025] The current conduction path includes at least one of the following:

[0026] The conductive path formed between the vehicle battery and the first upper bridge arm and the second lower bridge arm;

[0027] The conductive path formed between the vehicle battery and the first lower axle arm and the second upper axle arm.

[0028] In addition, to achieve the above objectives, the present invention also proposes a battery heating control system, which includes a motor controller, a first motor and a second motor, and the motor controller further includes a first inverter corresponding to the first motor and a second inverter corresponding to the second motor.

[0029] The motor controller is used to monitor the conduction status of the bridge arms of the first inverter and the second inverter in response to the battery heating signal.

[0030] The motor controller is also used to adjust the PWM signal of the bridge arm of the first inverter and / or the second inverter based on the monitoring results, so as to form a current conduction path between the first inverter, the second inverter and the vehicle battery, thereby heating the battery.

[0031] In addition, to achieve the above objectives, this application also proposes a battery heating control device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the battery heating control method as described above.

[0032] In addition, to achieve the above objectives, this application also proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the battery heating control method described above.

[0033] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the battery heating control method described above.

[0034] This invention monitors the conduction status of the bridge arms of the first and second inverters in response to a battery heating signal. Based on the monitoring results, it adjusts the PWM signals of the bridge arms of the first and / or second inverters to form a current conduction path between the first and second inverters and the vehicle battery, thereby heating the battery. This ensures the control timeliness between the two inverters in a dual-motor system, effectively solving the problem of ineffective coordinated control between the two inverters in a dual-motor drive scenario. It ensures control stability, effectively improves the battery heating effect in a dual-motor drive, ensures that the bridge arm conduction status of the two inverters remains favorable for battery heating, significantly increases the battery temperature rise rate, and thus improves the battery fast charging efficiency. It effectively avoids the problem of low battery preheating efficiency and difficulty in the battery entering a fast charging state. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of the battery heating control device in the hardware operating environment involved in the embodiments of the present invention;

[0038] Figure 2 This is a flowchart illustrating the first embodiment of the battery heating control method of the present invention;

[0039] Figure 3 This is a schematic diagram of the dual-motor series structure in the first embodiment of the battery heating control method of the present invention;

[0040] Figure 4 This is a schematic diagram of the bridge arm normalized structure in the first embodiment of the battery heating control method of the present invention;

[0041] Figure 5 A schematic diagram of the conductive structure between the first upper bridge arm and the second lower bridge arm;

[0042] Figure 6 A schematic diagram of the conduction structure between the first lower bridge arm and the second upper bridge arm;

[0043] Figure 7 A schematic diagram of the conduction structure between the first lower bridge arm and the second lower bridge arm;

[0044] Figure 8A schematic diagram of the conductive structure between the first upper bridge arm and the second upper bridge arm;

[0045] Figure 9 A schematic diagram showing the current variation trend for different bridge arm conduction combinations;

[0046] Figure 10 This is a flowchart illustrating the second embodiment of the battery heating control method of the present invention;

[0047] Figure 11 A schematic diagram showing the changes in inductor current under different bridge arm conduction conditions;

[0048] Figure 12 This is a flowchart illustrating the third embodiment of the battery heating control method of the present invention;

[0049] Figure 13 This is a schematic diagram illustrating the changing trend of inductor current during the traversal scanning process in the third embodiment of the battery heating control method of the present invention;

[0050] Figure 14 This is a schematic diagram of the dual inverter cycle synchronization process in the third embodiment of the battery heating control method of the present invention;

[0051] Figure 15 This is a structural block diagram of the first embodiment of the battery heating control system of the present invention.

[0052] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0053] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0054] Reference Figure 1 , Figure 1 This is a schematic diagram of the battery heating control device structure in the hardware operating environment involved in the embodiments of the present invention.

[0055] like Figure 1As shown, the battery heating control device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0056] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the battery heating control device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0057] like Figure 1 As shown, the memory 1005, which is a computer-readable storage medium, may include an operating system, a network communication module, a user interface module, and a battery heating control program.

[0058] exist Figure 1 In the battery heating control device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the battery heating control device of the present invention can be set in the battery heating control device, and the battery heating control device calls the battery heating control program stored in the memory 1005 through the processor 1001 and executes the battery heating control method provided in the embodiment of the present invention.

[0059] This invention provides a battery heating control method, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the battery heating control method of the present invention.

[0060] In this embodiment, the battery heating control method includes the following steps:

[0061] Step S10: In response to the battery heating signal, monitor the conduction status of the bridge arms of the first inverter and the second inverter.

[0062] It should be noted that this embodiment applies to the motor controller in the battery heating control system. The battery heating control system also includes a first motor and a second motor. The motor controller also includes a first inverter corresponding to the first motor and a second inverter corresponding to the second motor.

[0063] It should be understood that the executing entity of this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a motor controller, a control unit, or an electronic device capable of performing the above functions. The following description uses a motor controller as an example to illustrate this embodiment and the subsequent embodiments.

[0064] It should be noted that there are two technical approaches to battery heating: indirect heating and direct heating. Indirect heating can utilize heat-generating components such as PTC resistors, electric drive assemblies, and air conditioning compressors to heat the vehicle's coolant, which then transfers heat to the battery pack. Direct heating can be achieved by allowing current to flow through the battery pack, utilizing the battery pack's internal resistance to generate heat.

[0065] It should be understood that while indirect heating is simple in principle, it relies on coolant to conduct heat, resulting in limited heat transfer efficiency and relatively slow battery pack heating. Direct heating, on the other hand, utilizes the electric drive assembly to control the battery pack to repeatedly charge and discharge at high current, achieving self-heating through internal resistance, with no heat loss and high heating efficiency.

[0066] It should be noted that traditional single-drive assemblies suffer from NVH (noise, vibration, and harshness) issues and low battery pack temperature rise rates when directly heated. This embodiment utilizes a dual-drive assembly in series for direct heating, resulting in balanced three-phase motor currents. Furthermore, the heating current flowing through the battery pack is approximately equal to the sum of the three-phase motor currents, leading to a larger heating current and faster battery pack temperature rise compared to a single-drive assembly. Due to the balanced three-phase currents, the stator's combined magnetic field is zero, resulting in smaller torque ripple and radial electromagnetic force, thus improving NVH performance.

[0067] It should be noted that direct heating via dual-motor series connection requires coordinated control of two inverters, with one inverter's upper bridge arm conducting and the other's lower bridge arm conducting. When both inverters simultaneously conduct their upper or lower bridge arms, the current freewheels between the two drive assemblies without passing through the battery pack, failing to achieve the heating target. Therefore, dual-motor series heating necessitates strict control of the PWM timing of the two inverters to prevent simultaneous conduction of either the upper or lower bridge arms. Currently, there is no high-speed communication to ensure the timely control of each inverter in a dual-motor system, resulting in poor performance of direct battery heating via dual-motor drive and an inability to quickly preheat the battery.

[0068] It should be understood that the battery heating control system applied in this embodiment includes a first motor and a second motor. The motor controller further includes a first inverter corresponding to the first motor and a second inverter corresponding to the second motor. The battery heating control system in this embodiment is as follows: Figure 3 The dual-motor series connection structure shown is used as an example for illustration. The battery heating control system can also be other series connection structures.

[0069] It should be noted that the conduction of the three-phase bridge arms in the inverter can be any one phase, any two phases, or all three phases. Regardless of the conduction method, it does not affect the control principle of this embodiment. Therefore, this embodiment normalizes the three-phase bridge arms; that is, the three-phase upper bridge arm and three-phase lower bridge arm in the first inverter are simplified to the first upper bridge arm and the first lower bridge arm, and the three-phase upper bridge arm and three-phase lower bridge arm in the second inverter are simplified to the second upper bridge arm and the second lower bridge arm, as follows. Figure 4 As shown, the first motor and the second motor are connected in series, which is equivalent to two three-phase motors connected in series as an inductor used as an energy storage device. The three phases of the first motor are connected in parallel, and the three phases of the second motor are connected in parallel. The first inverter and the second inverter are connected to the vehicle battery. When the three-phase upper arm of the first inverter is connected in the above-described conduction method, it is considered that the first upper arm is conducting. Then, the total inductance connected in series through the neutral line is considered as a single inductor. (When both the first inverter and the second inverter are three-phase conducting, the three phases of the first motor and the second motor are connected in parallel; when the first inverter is two-phase conducting, the first motor should be two-phase connected in parallel).

[0070] It should be understood that the upper and lower bridge arms of the inverter use complementary PWM waveforms; that is, when the upper bridge arm is on, the lower bridge arm is off, and vice versa. Therefore, there are four possible combinations of bridge arm conduction in a dual inverter: the first upper bridge arm and the second lower bridge arm are on, the first lower bridge arm and the second upper bridge arm are on, the first upper bridge arm and the second upper bridge arm are on, and the first lower bridge arm and the second lower bridge arm are on, such as... Figure 5 , 6 As shown in Figures 7 and 8, among which Figure 5 When the first upper bridge arm and the second lower bridge arm are turned on, the inductor current increases (the rate of change is positive). At this time, a circuit is formed between the energy storage device, the first upper bridge arm, the second lower bridge arm and the battery, so as to heat the battery. Figure 6 When the first lower bridge arm and the second upper bridge arm are conducting, and the inductor current freewheels (with a very small rate of change), a circuit is formed between the energy storage device, the first lower bridge arm, the second upper bridge arm, and the battery, thereby heating the battery. Figure 7 When the first and second lower bridge arms are turned on, the inductor current decreases (the rate of change is negative). At this time, a circuit is formed between the energy storage device, the first lower bridge arm, and the second lower bridge arm, but not with the battery, so the battery cannot be heated. Figure 8In the bridge arm conduction condition where the first and second upper bridge arms are conducting, and the inductor current freewheels (with a very small rate of change), a circuit is formed between the energy storage device, the first upper bridge arm, and the second upper bridge arm, but not with the battery, thus preventing battery heating. The inductor current changes under the above four bridge arm conduction conditions are as follows: Figure 9 As shown, Figure 9 The current variation trend is shown for different conduction combinations.

[0071] Furthermore, in order to improve the heating efficiency of the dual motors, the first inverter includes a first upper bridge arm and a first lower bridge arm, and the second inverter includes a second upper bridge arm and a second lower bridge arm.

[0072] The current conduction path includes at least one of the following:

[0073] The conductive path formed between the vehicle battery and the first upper axle arm and the second lower axle arm;

[0074] The conductive path formed between the vehicle battery and the first lower axle arm and the second upper axle arm.

[0075] It should be noted that the conductive path formed between the vehicle battery and the first upper axle arm and the second lower axle arm is referenced. Figure 5 The conductive path formed between the vehicle battery and the first lower axle arm and the second upper axle arm is referenced. Figure 6 When the bridge arms of the first and second inverters are in operation, the following conditions apply: Figure 5 and Figure 6 Under the operating conditions shown, a current conduction path is formed between the first inverter, the second inverter, and the vehicle battery, enabling direct heating of the battery.

[0076] Step S20: Adjust the PWM signal of the bridge arm of the first inverter and / or the second inverter based on the monitoring results so that a current conduction path is formed between the first inverter, the second inverter and the vehicle battery to heat the battery.

[0077] It should be noted that, in order to heat the battery, this embodiment adjusts the PWM signal of the bridge arm of the first inverter and / or the second inverter based on the monitoring results. By controlling the on / off state of the first bridge arm in the first inverter and the second bridge arm in the second inverter, the conduction conditions of the first and second bridge arms are ensured to establish a current conduction path between the first inverter, the second inverter and the vehicle battery, thereby maximizing the time for establishing the charging and discharging circuit and improving the battery heating efficiency.

[0078] It should be understood that, since the dual-motor drive system requires high-speed communication to ensure the precise timing of the on / off states of the first bridge arm in the first inverter and the second bridge arm in the second inverter, this embodiment monitors the on / off conditions of the bridge arms of the first inverter and the second inverter, and adjusts the PWM signals of the bridge arms of the first inverter and / or the second inverter based on the monitoring results. This ensures that the on / off conditions of the first and second bridge arms after the control cycle adjustment can form a current conduction path between the two inverters and the battery, thereby achieving battery heating.

[0079] This embodiment monitors the conduction status of the bridge arms of the first and second inverters in response to the battery heating signal. Based on the monitoring results, it adjusts the PWM signals of the bridge arms of the first and / or second inverters to form a current conduction path between the first and second inverters and the vehicle battery, thereby heating the battery. This ensures the control timeliness between the two inverters in a dual-motor system, effectively solving the problem of ineffective coordinated control between the two inverters in a dual-motor drive scenario. It ensures control stability, effectively improves the battery heating effect of dual-motor drive, ensures that the bridge arm conduction status of the two inverters remains favorable for battery heating, significantly increases the battery temperature rise rate, thereby improving the battery fast charging efficiency and effectively avoiding the problem of low battery preheating efficiency and difficulty in entering the fast charging state.

[0080] refer to Figure 10 , Figure 10 This is a flowchart illustrating the second embodiment of the battery heating control method of the present invention.

[0081] Based on the first embodiment described above, in this embodiment, step S20 further includes:

[0082] Step S21: Based on the monitoring results, obtain the inductor current data during the conduction process of the bridge arms of the first inverter and the second inverter.

[0083] It should be noted that, referring to Figure 11 , Figure 11 This diagram illustrates the inductor current variations under different bridge arm conduction conditions. These bridge arm conduction conditions may include:

[0084] The first upper bridge arm of the first inverter and the second upper bridge arm of the second inverter are turned on simultaneously, that is, the rising edge of the PWM of the first inverter coincides with the rising edge of the PWM of the second inverter. If the first upper bridge arm and the second upper bridge arm are turned on simultaneously, the two ends of the inductor are at the same potential, and the inductor is in a freewheeling state. At this time, the current flows between the inductor and the bridge arm, without passing through the battery pack, and cannot play the role of battery heating.

[0085] The first upper bridge arm of the first inverter and the second lower bridge arm of the second inverter are turned on simultaneously. That is, the rising edge of the PWM signal of the first inverter bridge arm is opposite to the rising edge of the PWM signal of the second inverter bridge arm (coinciding with the falling edge of the second inverter, i.e., the rising edge of the PWM signal of the first inverter bridge arm and the falling edge of the PWM signal of the first inverter bridge arm occur at the same time or at a time close to the same time). If the first upper bridge arm and the second lower bridge arm are turned on simultaneously, the time to establish the charging and discharging circuit is maximized, and the maximum current can be generated (optimal case).

[0086] It is understandable that if the conduction times of the first and second upper bridge arms partially overlap, a charging and discharging circuit will be established for a period of time, and the current will increase. During the remaining time, the current will be in a freewheeling state, flowing between the inductor and the bridge arm without passing through the battery pack, and thus cannot achieve the function of heating the battery.

[0087] In practical implementation, in order to ensure the optimal heating effect of the battery heating control system, it is necessary to respond to the battery heating signal upon receiving the battery heating signal and adjust the timing of the bridge arm conduction of the first inverter and / or the second inverter so that the rising edge of the PWM of the first upper bridge arm and the falling edge of the PWM of the second upper bridge arm coincide as much as possible, thereby extending the battery heating time and improving the battery heating efficiency.

[0088] Step S22: Determine the target conduction time based on the inductor current data.

[0089] It should be noted that the target turn-on time is the moment when the rising edge of the bridge arm PWM signal of the first inverter and the falling edge of the bridge arm PWM signal of the second inverter occur simultaneously, or the moment when the falling edge of the bridge arm PWM signal of the first inverter and the rising edge of the bridge arm PWM signal of the second inverter occur simultaneously.

[0090] The target turn-on time includes the moment when the rising edge of the PWM signal of the first upper arm of the first inverter and the falling edge of the PWM signal of the second upper arm of the second inverter occur simultaneously. At this time, the first upper arm and the second lower arm are turned on at the same time. Figure 9 The time point at which the first upper bridge arm and the second lower bridge arm form a circuit; the target conduction time also includes the moment when the falling edge of the first upper bridge arm and the rising edge of the second bridge arm occur simultaneously, as shown in the example. Figure 9 The time point at which the first lower bridge arm and the second upper bridge arm form a loop.

[0091] It is understandable that this embodiment determines the optimal bridge arm conduction time by detecting the magnitude of the inductor current during the conduction process.

[0092] Furthermore, in order to determine the optimal bridge arm conduction condition and improve the battery temperature rise rate, step S22 above may include:

[0093] The absolute value of the inductor current at each moment during the conduction process of the bridge arm is determined based on the inductor current data;

[0094] The maximum and minimum values ​​during the bridge arm conduction process are determined based on the absolute value of the inductor current.

[0095] The target conduction time is determined based on the maximum value time and the minimum value time.

[0096] It should be noted that the minimum value can be the moment when the inductor current approaches 0 during the conduction of the bridge arm; the maximum value can be the moment when the absolute value of the inductor current is the largest.

[0097] For example, the second bridge arm of the second inverter is set to 1kHz and 50% duty cycle, with a period of 1ms which can be converted to 1000us. The first bridge arm is set to a period of 1001us and 50% duty cycle. During the bridge arm conduction process, there are moments when the absolute value of the inductor current is at its maximum and when the inductor current is close to 0. When the inductor current is close to 0, it means that the first and second upper bridge arms are conducting simultaneously. When the absolute value of the inductor current is at its maximum, it means that the first upper bridge arm and the second lower bridge arm are conducting simultaneously, maximizing the time to establish the charging and discharging circuit and generating the maximum current. This is the optimal bridge arm conduction condition. The target conduction time is determined based on the maximum and minimum value moments. Based on the target conduction time, the PWM signals of the bridge arms of the first inverter and / or the second inverter are adjusted to achieve coordinated control of the two inverters and improve battery heating efficiency.

[0098] Furthermore, in order to improve data accuracy and reduce data errors, step S22 above may include:

[0099] Multiple initial conduction times are determined based on inductor current data;

[0100] The target conduction time is obtained by aggregating the average values ​​of multiple initial conduction times.

[0101] It should be noted that, in order to avoid interference from current sampling glitches, the bridge arm conduction condition can be scanned repeatedly to obtain multiple segments of inductor current data, thereby extracting multiple initial conduction times. Then, the average values ​​of multiple initial conduction times are aggregated to obtain the target conduction time (for example, taking the average to obtain the optimal conduction time).

[0102] Step S23: Adjust the bridge arm PWM signal of the first inverter and / or the second inverter based on the target turn-on time.

[0103] It should be noted that when the PWM period of the first inverter is the same as that of the second inverter, the relative relationship between the rising edge of the PWM of the first upper arm and the falling edge of the PWM of the second upper arm will remain fixed.

[0104] When the PWM period of the first inverter is not equal to the PWM period of the second inverter, the relative relationship between the rising edge of the first upper bridge PWM and the falling edge of the second upper bridge PWM will change periodically, that is, there is a certain offset between the PWM period of the first inverter and the PWM period of the second inverter.

[0105] For example, the second inverter is PWM controlled according to a preset frequency and a 50% duty cycle, while the first inverter is PWM controlled according to a frequency that has a certain offset from the preset frequency and a 50% duty cycle. Since the PWM cycles of the first inverter and the second inverter are inconsistent, the PWM bridge conduction time of the first inverter and the second inverter gradually shifts, gradually transitioning from both the first inverter and the second inverter being on the bridge to the first inverter being on the bridge and the second inverter being off the bridge.

[0106] The control device detects the magnitude of the inductor current during the conduction process to determine the optimal conduction time of the first bridge arm. When the second round of PWM timing scan reaches this position, the period of the first bridge arm is set to be the same as that of the second bridge arm to achieve optimal conduction. This ensures that a conduction loop is formed between the first inverter, the second inverter, and the battery, thereby improving the battery heating efficiency.

[0107] This embodiment acquires inductor current data during the conduction process of the bridge arms of the first and second inverters based on monitoring results. The target conduction time is determined based on this data. The target conduction time is the moment when the rising edge of the bridge arm PWM signal of the first inverter and the falling edge of the bridge arm PWM signal of the second inverter occur simultaneously, or the moment when the falling edge of the bridge arm PWM signal of the first inverter and the rising edge of the bridge arm PWM signal of the second inverter occur simultaneously. Based on the target conduction time, the bridge arm PWM signals of the first and / or second inverters are adjusted to ensure that the bridge arm conduction is in optimal operating condition, thereby maximizing heating efficiency and improving the battery temperature rise rate.

[0108] refer to Figure 12 , Figure 12 This is a schematic flowchart of the third embodiment of the battery heating control method of the present invention.

[0109] Based on the above embodiments, in this embodiment, step S10, the method further includes:

[0110] Step S101: Obtain the first bridge arm PWM period of the first inverter and the second bridge arm PWM period of the second inverter.

[0111] It should be noted that the first arm PWM cycle can be the arm PWM control turn-on cycle of the first inverter, and the second arm PWM cycle can be the arm PWM control turn-on cycle of the second inverter. One arm PWM cycle can be the time required from the rising edge of the arm PWM signal to the rising edge of the PWM signal of the next identical arm.

[0112] It should be noted that when the PWM period of the first inverter is not equal to the PWM period of the second inverter, the relative relationship between the rising edge of the first upper bridge PWM and the falling edge of the second upper bridge PWM will change periodically. That is, there is a certain offset between the PWM period of the first inverter and the PWM period of the second inverter. The offset period can be the least common multiple of the PWM period of the first inverter and the PWM period of the second inverter.

[0113] Step S102: Determine the least common multiple between the PWM period of the first bridge arm and the PWM period of the second bridge arm.

[0114] It should be noted that, due to the inconsistency of the PWM cycles of the first inverter and the second inverter, the PWM bridge conduction time of the first inverter and the second inverter gradually shifts, from both the first inverter and the second inverter being on the bridge to the first inverter being on the bridge and the second inverter being off the bridge.

[0115] Understandably, for example, if the PWM period of the first bridge arm is 1000µs and the PWM period of the second bridge arm is 1005µs, the least common multiple time interval between the PWM periods of the first and second bridge arms is 201000 microseconds, or 0.201 seconds. By calculating the least common multiple between the PWM periods of the first and second bridge arms, it can be used to synchronize different frequency periods, ensuring that the two are aligned again at a certain point in time, thereby achieving precise control of the bridge arm timing of the dual inverters.

[0116] Step S103: Determine the traversal time based on the least common multiple.

[0117] For example, the second bridge arm of the second inverter is set to 1kHz and 50% duty cycle. The period of 1ms can be converted to 1000us. The first bridge arm is set to a period of 1001us and 50% duty cycle. Then, the traversal of the bridge arm conduction conditions of the first and second bridge arms can be taken as the least common multiple of the first and second bridge arms, LCM(1ms, 1.001ms) = 1.001s. That is, the traversal is performed within 1.001 seconds to determine the moment when the inductor current is the largest and the moment when the inductor current is close to 0 (i.e., the inductor current is the smallest). When the inductor current is close to 0, it means that the first upper bridge arm and the second upper bridge arm are conducting at the same time. When the absolute value of the inductor current is the largest, it means that the first upper bridge arm and the second lower bridge arm are conducting at the same time.

[0118] Therefore, after a 1.001-second traversal scan, the optimal conduction time of the first bridge arm can be obtained. When the second round of traversal reaches this position, the period of the first bridge arm is set to be the same as that of the second bridge arm to achieve optimal conduction. Figure 13 , Figure 13 This diagram illustrates the changing trend of inductor current during the traversal scanning of the rising edge phase relationship of the PWM.

[0119] Step S104: Scan the bridge arm switch signals of the first inverter and the second inverter traversally according to the traversal duration to monitor the conduction status of the bridge arms of the first inverter and the second inverter.

[0120] Understandably, referring to Figure 14 , Figure 14 This is a schematic diagram of the dual inverter cycle synchronization process. The control device acquires the PWM cycle of the second bridge arm (e.g., the second cycle) and the PWM cycle of the first bridge arm (e.g., the first cycle). Based on the least common multiple of the first cycle and the second cycle, it determines the total time of the scanning cycle for the bridge arm conduction condition of the first inverter, and calculates the number of corresponding first cycles, which is recorded as the upper limit of the count value of the first cycle corresponding to the scanning cycle. It records the maximum and minimum values ​​of the absolute value of the inductor current and their times in the scanning cycle of the first bridge arm (the number of first cycles). It determines whether the calculated value of the first cycle is greater than the upper limit of the calculated value of the first cycle corresponding to the scanning cycle. If so, it determines whether the calculated value of the first control cycle is equal to the moment when the absolute value of the inductor current is at its maximum. If so, it sets the control cycle of the first bridge arm to the second cycle, thereby realizing the cycle synchronization of the dual inverters, determining the optimal operating condition, waiting for a specific time, and then switching to the optimal operating condition, thus improving the battery heating efficiency.

[0121] This embodiment obtains the PWM period of the first bridge arm of the first inverter and the PWM period of the second bridge arm of the second inverter, determines the least common multiple between the PWM periods of the first and second bridge arms, determines the traversal time based on the least common multiple, and traverses and scans the bridge arm switching cycles of the first and second inverters according to the traversal time to monitor the bridge arm conduction conditions of the first and second inverters. Since this embodiment calculates the least common multiple between the PWM periods of the first and second bridge arms, it synchronizes the different PWM periods of the two inverters based on the least common multiple, thereby aligning the periods when the PWM periods of the two inverters are inconsistent, maintaining the optimal bridge arm conduction condition, and improving battery heating efficiency.

[0122] Furthermore, embodiments of the present invention also propose a computer-readable storage medium storing a battery heating control program, which, when executed by a processor, implements the steps of the battery heating control method described above.

[0123] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0124] The aforementioned computer-readable storage medium may be included in the battery heating control device; or it may exist independently and not assembled into the battery heating control device.

[0125] Furthermore, this invention also proposes a computer program product, including a battery heating control program, which, when executed by a processor, implements the steps of the battery heating control method described above.

[0126] The specific implementation of the computer program product of the present invention is basically the same as the embodiments of the battery heating control method described above, and will not be repeated here.

[0127] Reference Figure 15 , Figure 15 This is a structural block diagram of the first embodiment of the battery heating control system of the present invention.

[0128] like Figure 15 As shown, the battery heating control system proposed in this embodiment of the invention includes a motor controller, a first motor and a second motor, and the motor controller also includes a first inverter corresponding to the first motor and a second inverter corresponding to the second motor.

[0129] The motor controller is used to monitor the conduction status of the bridge arms of the first inverter and the second inverter in response to the battery heating signal.

[0130] The motor controller is also used to adjust the PWM signal of the bridge arm of the first inverter and / or the second inverter based on the monitoring results, so as to form a current conduction path between the first inverter, the second inverter and the vehicle battery, thereby heating the battery.

[0131] Furthermore, the motor controller is also used to acquire inductor current data during the conduction process of the bridge arms of the first inverter and the second inverter based on the monitoring results; determine the target conduction time based on the inductor current data, wherein the target conduction time is the moment when the rising edge of the bridge arm PWM signal of the first inverter and the falling edge of the bridge arm PWM signal of the second inverter occur simultaneously, or the moment when the falling edge of the bridge arm PWM signal of the first inverter and the rising edge of the bridge arm PWM signal of the second inverter occur simultaneously; and adjust the bridge arm PWM signals of the first inverter and / or the second inverter based on the target conduction time.

[0132] Furthermore, the motor controller is also used to determine the absolute value of the inductor current at each moment during the conduction process of the bridge arm based on the inductor current data; to determine the maximum and minimum value moments during the conduction process of the bridge arm based on the absolute value of the inductor current; and to determine the target conduction moment based on the maximum and minimum value moments.

[0133] Furthermore, the motor controller is also used to determine multiple initial conduction times based on inductor current data; and to aggregate the average values ​​of the multiple initial conduction times to obtain the target conduction time.

[0134] Furthermore, the motor controller is also used to acquire the first bridge arm PWM period of the first inverter and the second bridge arm PWM period of the second inverter; determine the least common multiple between the first bridge arm PWM period and the second bridge arm PWM period; determine the traversal duration based on the least common multiple; and traverse and scan the bridge arm switching signals of the first inverter and the second inverter according to the traversal duration to monitor the bridge arm conduction status of the first inverter and the second inverter.

[0135] Furthermore, the first inverter includes a first upper bridge arm and a first lower bridge arm, and the second inverter includes a second upper bridge arm and a second lower bridge arm; the current conduction path includes at least one of the following: a conduction path formed between the vehicle battery and the first upper bridge arm and the second lower bridge arm; a conduction path formed between the vehicle battery and the first lower bridge arm and the second upper bridge arm.

[0136] This embodiment monitors the conduction status of the bridge arms of the first and second inverters in response to the battery heating signal. Based on the monitoring results, it adjusts the PWM signals of the bridge arms of the first and / or second inverters to form a current conduction path between the first and second inverters and the vehicle battery, thereby heating the battery. This ensures the control timeliness between the two inverters in a dual-motor system, effectively solving the problem of ineffective coordinated control between the two inverters in a dual-motor drive scenario. It ensures control stability, effectively improves the battery heating effect of dual-motor drive, ensures that the bridge arm conduction status of the two inverters remains favorable for battery heating, significantly increases the battery temperature rise rate, thereby improving the battery fast charging efficiency and effectively avoiding the problem of low battery preheating efficiency and difficulty in entering the fast charging state.

[0137] The battery heating control system provided in this application, employing the battery heating control method in the above embodiments, can solve the technical problem of battery heating control. Compared with the prior art, the beneficial effects of the battery heating control system provided in this application are the same as those of the battery heating control method provided in the above embodiments, and other technical features in the battery heating control system are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0138] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0139] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0140] In addition, for technical details not described in detail in this embodiment, please refer to the battery heating control method provided in any embodiment of the present invention, which will not be repeated here.

[0141] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0142] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0143] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0144] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A battery heating control method, characterized by, The method is applied to a motor controller in a battery heating control system, the battery heating control system further comprising a first motor and a second motor, the motor controller further comprising a first inverter corresponding to the first motor, and a second inverter corresponding to the second motor, the battery heating control method comprising: monitoring, in response to a battery heating signal, a bridge arm conduction state of the first inverter and the second inverter; adjusting, based on the monitoring result, a bridge arm PWM signal of the first inverter and / or the second inverter, so as to form a current conduction path between the first inverter, the second inverter and a vehicle battery, and to realize battery heating.

2. The battery heating control method of claim 1, wherein, The adjusting, based on the monitoring result, of the bridge arm PWM signal of the first inverter and / or the second inverter comprises: obtaining, based on the monitoring result, inductance current data in a bridge arm conduction process of the first inverter and the second inverter; determining, according to the inductance current data, a target conduction time, the target conduction time being a time when a rising edge of the bridge arm PWM signal of the first inverter and a falling edge of the bridge arm PWM signal of the second inverter occur simultaneously, or a time when a falling edge of the bridge arm PWM signal of the first inverter and a rising edge of the bridge arm PWM signal of the second inverter occur simultaneously; adjusting, based on the target conduction time, the bridge arm PWM signal of the first inverter and / or the second inverter.

3. The battery heating control method of claim 2, wherein, The determining, according to the inductance current data, of the target conduction time comprises: determining, according to the inductance current data, an inductance current absolute value at each time in the bridge arm conduction process; determining, based on the inductance current absolute value, a maximum value time and a minimum value time in the bridge arm conduction process; determining, according to the maximum value time and the minimum value time, the target conduction time.

4. The battery heating control method of claim 3, wherein, The determining, according to the inductance current data, of the target conduction time comprises: determining, according to the inductance current data, a plurality of initial conduction times; performing average value aggregation on the plurality of initial conduction times to obtain the target conduction time.

5. The battery heating control method according to any one of claims 1 to 4, wherein The monitoring of the bridge arm conduction state of the first inverter and the second inverter comprises: obtaining a first bridge arm PWM period of the first inverter and a second bridge arm PWM period of the second inverter; determining a least common multiple between the first bridge arm PWM period and the second bridge arm PWM period; determining a traversal duration based on the least common multiple; traversing and scanning, according to the traversal duration, a bridge arm switch signal of the first inverter and the second inverter, so as to monitor the bridge arm conduction state of the first inverter and the second inverter.

6. The battery heating control method according to any one of claims 1 to 4, wherein The first inverter comprises a first upper bridge arm and a first lower bridge arm, and the second inverter comprises a second upper bridge arm and a second lower bridge arm; The current conduction path comprises at least one of: a conduction path formed between the vehicle battery, the first upper bridge arm and the second lower bridge arm; a conduction path formed between the vehicle battery, the first lower bridge arm and the second upper bridge arm.

7. A battery heating control system, characterized by, The battery heating control system comprises a motor controller, and further comprises a first motor and a second motor, the motor controller further comprises a first inverter corresponding to the first motor, and a second inverter corresponding to the second motor; The motor controller is configured to monitor the bridge arm conduction state of the first inverter and the second inverter in response to the battery heating signal; The motor controller is further configured to adjust the bridge arm PWM signal of the first inverter and / or the second inverter based on the monitoring result, so as to form a current conduction path between the first inverter, the second inverter and the vehicle battery, and to realize battery heating.

8. A battery heating control device, characterized by, The battery heating control device comprises a memory, a processor, and a battery heating control program stored in the memory and executable on the processor, and the battery heating control program is configured to implement the battery heating control method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a battery heating control program, and the battery heating control program is executed by the processor to implement the battery heating control method according to any one of claims 1 to 6.

10. A computer program product, characterised in that, The computer program product comprises a battery heating control program, and the battery heating control program is executed by the processor to implement the steps of the battery heating control method according to any one of claims 1 to 6.

Images