A power battery self-heating system and method based on electric drive inverter reconstruction

Abstract

This invention discloses a power battery self-heating system and method based on electric drive inverter reconfiguration. The system includes an inverter connected in parallel across the power battery, comprising three sets of IGBT bridges connected in parallel. A drive motor includes three winding inductors, one end of which is interconnected, and the other end of each winding inductor is connected to the intermediate circuit of the three IGBT bridges, forming three connection terminals. The positive terminal of the power battery has two branches. One branch is connected to the positive terminal of the inverter via a first relay, and the other branch is connected to one end of a capacitor via a series adjustable resistor and a second relay. One or two of these connection terminals are connected to the other end of the capacitor. A controller adjusts the states of the first relay, the second relay, and the adjustable resistor based on the monitored temperature of the power battery to switch between the drive circuit and the self-heating circuit. This invention enables safe, efficient, and low-power self-heating of the power battery.

Description

Technical Field

[0001] This invention relates to the field of automotive power battery thermal management technology, specifically to a power battery self-heating system and method based on electric drive inverter reconfiguration. Background Technology

[0002] With the advent of the new energy era, the widespread application of power batteries has become an unstoppable trend; however, when facing extremely cold environments, the electrical performance of power batteries used in new energy vehicles will be greatly reduced, and their service life will be greatly affected. Rapidly increasing the body temperature of power batteries is a prerequisite for the rapid large-scale promotion and use of power batteries.

[0003] Currently, most power battery pack systems heat the battery by transferring heat to it through an external heating system or heating circuit. For example, Chinese patent application No. 201810496455.5 discloses a battery pack heating device and control method, which designs the power battery heating device to be portable and placed outside the vehicle as a separate product. However, it contains power conversion components, heating interfaces, and heating control modules, making it very complex and increasing the cost of the heating device while reducing its versatility. Another example is Chinese patent application No. 202111033087.9, which discloses a vehicle battery self-heating method and device. Its self-designed LC vibration unit is connected to the power battery, and the vibration circuit is also independent of the electric drive system. However, this greatly increases the complexity and cost of the entire system and reduces its reliability. In addition, Chinese patent document with application number 201810316487.2 discloses a method and device for self-heating of lithium-ion battery pulse discharge, which mainly uses high-frequency pulse discharge control to heat the battery itself. However, it requires the power battery to still have sufficient power in extremely cold environments and requires a complete high-frequency discharge device. It is not suitable for low-power application scenarios. The feasibility of this solution is low and it is not conducive to industrialization and promotion. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a power battery self-heating system and method based on electric drive inverter reconfiguration for application scenarios where power batteries cannot be used normally in extremely cold environments and their service life is shortened. This solves the problem of non-destructive heating of power batteries, enables the power battery body to heat up rapidly without affecting its service life and ensuring the safety of use, thereby achieving the goal of using power batteries in all scenarios.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides a power battery self-heating system based on an electric drive inverter, comprising a power battery, an inverter, a drive motor, and a controller. The inverter includes three IGBT bridges connected in parallel across the power battery. The drive motor includes three winding inductors, one end of each winding inductor being interconnected, and the other end of each winding inductor being connected to the intermediate circuit of the three IGBT bridges, forming three connection terminals. The positive terminal of the power battery is connected to two branches, one of which is connected to the positive terminal of the inverter via a first relay, and the other branch is connected to one end of a capacitor via a series adjustable resistor and a second relay, with one or two connection terminals connected to the other end of the capacitor. The controller is used to adjust the states of the first relay, the second relay, and the adjustable resistor according to the monitored temperature of the power battery, so as to realize the switching operation of the drive circuit and the self-heating circuit.

[0007] In conjunction with the first aspect, preferably, the negative terminal of the inverter is connected to the negative terminal of the power battery via a third relay, and the third relay is connected to the controller.

[0008] In conjunction with the first aspect, preferably, each IGBT bridge group includes two IGBT insulated-gate transistors; the first IGBT bridge group includes a first IGBT and a fourth IGBT, the second IGBT bridge group includes a second IGBT and a fifth IGBT, and the third IGBT bridge group includes a third IGBT and a sixth IGBT; the three winding inductors of the drive motor are a first winding inductor, a second winding inductor, and a third winding inductor; the other end of the first winding inductor is connected to the intermediate circuit of the first IGBT bridge group to form a first connection terminal; the other end of the second winding inductor is connected to the intermediate circuit of the second IGBT bridge group to form a second connection terminal; and the other end of the third winding inductor is connected to the intermediate circuit of the third IGBT bridge group to form a third connection terminal.

[0009] In conjunction with the first aspect, preferably, the other end of the capacitor is connected to the first connection terminal.

[0010] In conjunction with the first aspect, preferably, the other end of the capacitor is connected to two parallel circuits, one of which is connected to the first connection terminal and the other is connected to the second connection terminal.

[0011] In conjunction with the first aspect, preferably, when the self-heating circuit is running, the first relay is in the off state. The current flows from the positive terminal of the power battery through another branch, sequentially through the adjustable resistor, the second relay, and the capacitor, and then through the first connection terminal to the first winding inductor. The current flows out from the second winding inductor and the third winding inductor, respectively. The current flowing out from the second winding inductor flows through the second connection terminal to the fifth IGBT, and then merges with the current flowing out from the third winding inductor through the third connection terminal to the sixth IGBT, thus forming a complete self-heating circuit for the power battery.

[0012] In conjunction with the first aspect, preferably, when the self-heating circuit is running, the first relay is in the off state, and the current flows from the positive terminal of the power battery through another branch in sequence through the adjustable resistor, the second relay, and the capacitor, and then through the first connection terminal and the second connection terminal respectively through the first winding inductor and the second winding inductor, and flows out from the third winding inductor, through the third connection terminal through the sixth IGBT and then flows back to the negative terminal of the power battery, so as to form a complete power battery self-heating circuit.

[0013] In conjunction with the first aspect, preferably, when the drive circuit is running, the first relay is in a closed state and the second relay is in an open state.

[0014] In a second aspect, the present invention provides a method for self-heating a power battery using a power battery self-heating system based on electric drive inverter reconfiguration as described in any of the first aspects, the method comprising:

[0015] Obtain the initial temperature of a single power battery cell;

[0016] If the initial temperature is lower than the temperature required for the drive circuit to operate, the first relay is disconnected and the second relay is closed at the same time, so that the power battery enters the self-heating charge and discharge cycle mode.

[0017] Real-time monitoring of the temperature of individual battery cells during the self-heating charge-discharge cycle of the power battery;

[0018] Determine whether the current temperature of the individual battery cell has reached the set temperature threshold;

[0019] If the current temperature reaches the set temperature threshold, the second relay will be disconnected to stop the heating of the power battery.

[0020] In conjunction with the second aspect, preferably, after real-time monitoring of the temperature of a single cell during the self-heating charge-discharge cycle of the power battery, the method further includes the following steps:

[0021] Calculate the current temperature rise rate of the individual battery cell based on the monitored temperature of the individual cell;

[0022] If the current temperature rise rate reaches the first threshold, the resistance value of the adjustable resistor is adjusted so that the heating power of the power battery is reduced to a preset power.

[0023] If the current rate of temperature rise reaches the second threshold, the second relay is disconnected to stop the heating of the power battery.

[0024] In conjunction with the second aspect, preferably, if the second relay becomes stuck when it is disconnected, the third relay is immediately disconnected to break the self-heating electrical circuit.

[0025] In conjunction with the second aspect, preferably, before the power battery enters the self-heating charge-discharge cycle, it also includes:

[0026] Disconnect the second relay and keep the vehicle in the parked position;

[0027] The alternating drive system operates in a first and second state to align the rotor teeth of the drive motor with the small teeth of the A-phase stator magnetic poles; the first state includes closing the first and third relays; the second state includes opening the first and third relays.

[0028] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0029] 1. The power battery self-heating system and method based on electric drive inverter reconfiguration provided by the present invention effectively utilizes the energy conversion principle of the inductor and capacitor by connecting the power battery self-heating circuit in series. Furthermore, the sinusoidal AC current generated by the LC resonant circuit can perform non-destructive charging and discharging of the power battery, thereby realizing the switching operation of the drive circuit and the self-heating circuit without affecting the service life of the power battery.

[0030] 2. The system of the present invention sets an adjustable resistor in the self-heating circuit of the power battery to protect the circuit while adjusting the current in the circuit, so as to realize the adjustable power of the self-heating of the power battery, and thus more effectively control the body temperature of the power battery.

[0031] 3. The method of the present invention takes into account the prevention of thermal runaway during the self-heating process of the power battery, and adopts a two-level early warning mechanism. First, it monitors the temperature rise rate of the individual cell in real time. If the current temperature rise rate reaches the first threshold, it adjusts the resistance value of the adjustable resistor in time to reduce the heating power of the power battery to a preset power. Second, if the current temperature rise rate reaches the second threshold, it disconnects the second relay in time. In addition, the system of the present invention also redundantly designs a third relay to prevent thermal runaway accidents caused by the adhesion of the second relay.

[0032] 4. The method of the present invention suppresses the electromagnetic torque caused by the self-heating circuit. In the parking mode, the first and second operating states of the drive system are alternately driven, which can effectively reduce the peak value of the electromagnetic torque, thereby weakening the noise and vibration generated by the motor during the self-heating process.

[0033] 5. This invention reconfigures the electric drive inverter by connecting one or two terminals to the other end of a capacitor, and designs the current in the star winding inductor of the drive motor as "one in, two out" or "two out, one in," effectively utilizing the drive system circuit principle to achieve energy storage and release of the power battery self-heating system without affecting the drive system circuit. The invention also utilizes locally sourced materials to develop the power battery self-heating system, reducing the heating cost of the power battery system and achieving multiple uses of the drive system's electrical components. Furthermore, the self-heating system design is simple and reliable, avoiding complex modifications to the drive system, facilitating rapid product updates and iterations, and making it suitable for widespread use. Attached Figure Description

[0034] Figure 1 A schematic diagram of the structure of a power battery self-heating system based on electric drive inverter reconfiguration, where the current of the star-shaped winding inductor is "one-in, two-out" according to an embodiment of the present invention.

[0035] Figure 2 A schematic diagram of the structure of a power battery self-heating system based on electric drive inverter reconfiguration, where the current of the star-shaped winding inductor has "two outputs and one input" in an embodiment of the present invention.

[0036] Figure 3 This is a flowchart illustrating the self-heating method of the power battery self-heating system utilizing inverter reconfiguration provided in an embodiment of the present invention.

[0037] Figure 4 This is a flowchart illustrating the two-stage early warning mechanism in the power battery self-heating method of the power battery self-heating system reconfigured by inverter provided in an embodiment of the present invention.

[0038] In the diagram: 1. Power battery; 2. Adjustable resistor; 3. First relay; 4. Second relay; 5. Capacitor; 6. Inverter; 601. First IGBT; 602. Second IGBT; 603. Third IGBT; 604. Fourth IGBT; 605. Fifth IGBT; 606. Sixth IGBT; 614. First IGBT bridge; 625. Second IGBT bridge; 636. Third IGBT bridge; 7. Drive motor; 701. First winding inductor; 702. Second winding inductor; 703. Third winding inductor; 12. Controller. Detailed Implementation

[0039] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0040] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0041] like Figure 1 As shown in the figure, this embodiment of the invention introduces a power battery self-heating system based on electric drive inverter reconfiguration, including a power battery 1, an inverter 6, a drive motor 7, and a controller 12; specifically, the inverter 6 includes three sets of IGBT bridges connected in parallel across the two ends of the power battery; each set of IGBT bridges includes two IGBT insulated-gate transistors; each IGBT insulated-gate transistor is composed of a diode and a switching transistor; wherein, the first set of IGBT bridges 614 includes a first IGBT 604 and a fourth IGBT 604, the second set of IGBT bridges 625 includes a second IGBT 602 and a fifth IGBT 605, and the third set... The IGBT bridge 636 includes a third IGBT 603 and a sixth IGBT 606; the drive motor 7 includes three winding inductors, one end of each winding inductor being star-connected to each other; the other end of the first winding inductor 701 of the drive motor 7 is connected to the intermediate circuit of the first group of IGBT bridges 614 to form a first connection terminal; the other end of the second winding inductor 702 of the drive motor 7 is connected to the intermediate circuit of the second group of IGBT bridges 625 to form a second connection terminal; the other end of the third winding inductor 703 of the drive motor 7 is connected to the intermediate circuit of the third group of IGBT bridges 636 to form a third connection terminal.

[0042] Furthermore, the positive terminal of the power battery 1 is connected to two branches. One branch is connected to the positive terminal of the inverter 6 through the first relay 3, and the other branch is connected to one end of the capacitor 5 through the series-connected adjustable resistor 2 and the second relay 4. The other end of the capacitor 5 is connected to the first connection terminal. The controller 12 is used to adjust the state of the first relay 3, the second relay 4 and the adjustable resistor 2 according to the monitored temperature of the power battery 1, so as to realize the switching operation of the drive circuit and the self-heating circuit.

[0043] In one embodiment of the present invention, the negative terminal of the inverter 6 is connected to the negative terminal of the power battery 1 through a third relay 9, and the third relay 9 is connected to the controller 12. In this embodiment of the present invention, the third relay 9 is used to protect the self-heating circuit to prevent thermal runaway of the power battery 1.

[0044] As an embodiment of the present invention, when the drive circuit is running, the first relay 3 is in a closed state and the second relay 4 is in an open state. The drive circuit is mainly based on the power battery 1, the inverter 6, and the drive motor 7. The current flows from the positive terminal of the power battery 1 through the first relay 3 to the inverter 6 and the drive motor 7, and then flows back to the negative terminal of the power battery 1 through the third relay 9.

[0045] Specifically, for Figure 1 The self-heating system for a power battery based on an electric drive inverter, as shown, operates with the first relay 3 in the off state. Current flows from the positive terminal of the power battery 1 through another branch, sequentially passing through the adjustable resistor 2, the second relay 4, and the capacitor 5. It then flows through the first connection terminal and the first winding inductor 701, exiting from the second winding inductor 702 and the third winding inductor 703 respectively. The current exiting from the second winding inductor 702 flows through the second connection terminal and the fifth IGBT 605, where it merges with the current exiting from the third winding inductor 703 flowing through the third connection terminal and the sixth IGBT 606, ultimately converging at the negative terminal of the power battery 1 to form a complete self-heating electrical circuit. It should be noted that... Figure 1 The self-heating system for power batteries based on electric drive inverter reconfiguration shown here uses a short-circuit design for one IGBT bridge and utilizes the switching devices of the other two IGBT bridges to conduct the charging and discharging current of the heating circuit. This adjusts the control strategy without changing the control principle, which is beneficial to the realization of the self-heating control strategy of power battery 1. The current of the star winding inductor of drive motor 7 is designed with "one input and two outputs", which effectively utilizes the drive system circuit principle to realize the energy storage and release of the self-heating system for power batteries, and does not affect the drive system circuit.

[0046] like Figure 2 As shown in the illustration, this invention also introduces another power battery self-heating system based on electric drive inverter reconfiguration; such as Figure 2 The structure of the power battery self-heating system is the same as the above. Figure 1 The structures of their power battery self-heating systems are largely the same, with the only difference being... Figure 1 The other end of capacitor 5 is connected to the first connection terminal, while Figure 2 The other end of the capacitor 5 is connected to two parallel circuits, one of which is connected to the first connection terminal and the other is connected to the second connection terminal.

[0047] Specifically, for Figure 2 The self-heating system for a power battery based on an electric drive inverter, as shown, operates with the first relay 3 in the off state during self-heating circuit operation. Current flows from the positive terminal of the power battery 1 through another branch, sequentially passing through the adjustable resistor 2, the second relay 4, and the capacitor 5. It then flows through the first and second connection terminals, through the first winding inductor 701 and the second winding inductor 702, and exits from the third winding inductor 703. After passing through the third connection terminal and the sixth IGBT 606, it returns to the negative terminal of the power battery 1, forming a complete self-heating electrical circuit for the power battery. It should also be noted that… Figure 2 The self-heating system for power batteries based on the reconfiguration of the electric drive inverter shown features a short-circuit design for the two IGBT bridges. The switching devices of the remaining IGBT bridge are used to conduct the charging and discharging current of the heating circuit. The control principle is not changed, only the control strategy is adjusted, which is beneficial to the realization of the self-heating control strategy of power battery 1. The current of the star winding inductor of drive motor 7 is designed with "two inputs and one output", which effectively utilizes the drive system circuit principle to realize the energy storage and release of the self-heating system for power batteries, and does not affect the drive system circuit.

[0048] Furthermore, as an essential device in new energy vehicles, the electric drive system is optimally reconfigured into a self-heating system for the power battery 1 in this embodiment of the invention. To avoid system malfunction caused by simultaneous operation of both systems, the drive circuit will be suspended when the self-heating circuit of the power battery 1 is running. (Refer to...) Figure 1As shown, controller 12 is used for centralized control of the self-heating of power battery 1. Controller 12 determines whether to activate the self-heating mode based on the detected temperature of a single cell in power battery 1. If a heating signal is output, the second relay 4 is closed, and the first relay 3 is opened, allowing the system to enter self-heating mode. Power battery 1 then performs AC charging and discharging. During this time, the self-heating circuit short-circuits the first IGBT bridge 614 via the first connection terminal. When there is no current in the three winding inductors and no voltage in capacitor 5, the current generated by power battery 1 gradually flows through the three winding inductors and capacitor 5, forming a self-heating discharge circuit. When the voltage of capacitor 5 reaches the voltage across power battery 1, power battery 1 stops outputting current, while the three winding inductors continue to discharge. The current output flows through the power battery 1 and is transferred to the capacitor 5 until the current decreases to zero. At this time, the voltage of the capacitor 5 will be higher than the voltage across the power battery 1. The capacitor 5 begins to gradually discharge into the power battery 1, and the current in the three winding inductors will gradually increase. When the voltage of the capacitor 5 decreases, the current in the self-heating charging circuit gradually decreases. At this time, the energy stored in the three winding inductors will be converted into current to replenish the self-heating circuit until the energy stored in the three winding inductors and the capacitor 5 is exhausted. This forms a complete self-heating charging and discharging cycle of the power battery 1. It should be noted that the current in the discharging circuit flows through the switching transistors of the fifth IGBT 605 and the sixth IGBT 606, and the current in the charging circuit flows through the diodes of the fifth IGBT 605 and the sixth IGBT 606.

[0049] Furthermore, during the self-heating charge-discharge cycle of the power battery 1, the controller 12 synchronously monitors the temperature and temperature rise rate of the individual cells of the power battery 1 during the charge-discharge process. Based on the temperature rise rate, the controller adjusts the resistance value of the resistor 2 to change the current in the self-heating circuit, thereby adjusting the internal heat generation rate of the power battery 1. This achieves rapid temperature rise while ensuring the safety and lifespan of the power battery 1. Finally, the controller 12 determines whether the temperature of the individual cells of the power battery 1 has reached the set temperature threshold. If the temperature of the individual cells reaches the set temperature threshold, the second relay 4 is disconnected, and the self-heating of the power battery is stopped.

[0050] like Figure 3 As shown in the embodiments, the present invention also introduces a method utilizing the above-described... Figure 1 or Figure 2 The self-heating method for a power battery in any of the provided power battery self-heating systems based on electric drive inverter reconfiguration specifically includes the following steps:

[0051] Step S1: Obtain the initial temperature of the first single cell of the power battery;

[0052] Step S2: If the initial temperature is lower than the temperature required for the drive circuit to operate, disconnect the first relay 3 and simultaneously close the second relay 4 to allow the power battery 1 to enter the self-heating charge-discharge cycle mode.

[0053] Step S3: Monitor the temperature of individual cells in real time during the self-heating charge-discharge cycle of power battery 1;

[0054] Step S4: Determine whether the current temperature of the single cell has reached the set temperature threshold;

[0055] Step S5: If the current temperature reaches the set temperature threshold, disconnect the second relay 4 to stop the heating of the power battery.

[0056] As an embodiment of the present invention, considering the potential risk of thermal runaway during the use of the self-heating system of the power battery 1, the method of the present invention adopts a two-level early warning mechanism, specifically, as follows: Figure 4 As shown, after performing step 3 provided in this embodiment, the following steps are also included:

[0057] Step a: Calculate the current temperature rise rate of the individual battery cell based on the monitored temperature of the individual cell;

[0058] Step b: If the current temperature rise rate reaches the first threshold, adjust the resistance value of the adjustable resistor 2 to reduce the heating power of the power battery 1 to a preset power.

[0059] Step c: If the current temperature rise rate reaches the second threshold, disconnect the second relay 4 to stop the heating of the power battery.

[0060] In step d, if the second relay 4 becomes stuck when it is disconnected, the third relay 9 is immediately disconnected to break the self-heating electrical circuit.

[0061] Furthermore, during the self-heating process of the power battery 1, the heating current flowing through the winding inductance will cause the drive motor 7 to generate electromagnetic torque. The electromagnetic torque 7 will pulsate with the amplitude of the AC excitation, which can easily cause vibration and noise problems in the drive motor 7. The method provided in this embodiment of the invention utilizes the alternating operation of two states of the drive system before the power battery enters the self-heating charge-discharge cycle to reduce the vibration and noise of the drive motor 7. The specific steps include:

[0062] Disconnect the second relay 4 and keep the vehicle in the parked position;

[0063] The first and second operating states of the alternating drive system are used to align the rotor teeth of the drive motor 7 with the small teeth of the A-phase stator magnetic poles.

[0064] In the first operating state, the first relay 3 and the third relay 9 are closed. The current flows through the switching transistor of the first IGBT 601, enters the first winding inductor 701, and flows out from the second winding inductor 702 and the third winding inductor 703 respectively. Then it enters the fifth IGBT 605 and the sixth IGBT 606 respectively, passes through the third relay 9, and finally flows back to the power battery 1. In the second operating state, the first relay 3 and the third relay 9 are opened. The current stored in the three winding inductors flows in the same direction. The current flows out from the fifth IGBT 605 and the sixth IGBT 606 respectively, and flows back to the three winding inductors through the diode of the fourth IGBT 604. The DC current generated by the three winding inductors produces an appropriate torque to reduce the peak value of the electromagnetic torque, and then performs self-heating, thereby achieving the purpose of reducing motor noise and vibration.

[0065] In summary, the power battery self-heating system and method based on electric drive inverter reconfiguration provided by this invention uses a capacitor 5 connected in series with the winding inductance of the drive motor 7 to design the power battery 1 self-heating system for electric drive inverter reconfiguration. The IGBT bridge of the electric drive inverter is short-circuited, and other un-short-circuited IGBT bridges are used to control the start and stop of the charging and discharging current of the power battery self-heating circuit. An adjustable resistor 2 is set in the self-heating circuit of the power battery 1 to protect the circuit and adjust the current magnitude. Furthermore, to prevent thermal runaway during the self-heating process of the power battery 1, a two-level early warning mechanism is adopted to monitor the temperature rise of the power battery 1 in real time, and a redundant third relay 9 is designed at the negative terminal of the power battery 1 to prevent thermal runaway accidents caused by the adhesion of the second relay 4. This effectively solves the problem of non-destructive heating of the power battery and achieves rapid heating of the power battery 1 body without affecting its service life or ensuring safety, thus broadening the applicable scenarios. The solution of this invention is highly feasible and suitable for industrial application.

[0066] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0068] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0069] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0070] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A power battery self-heating system based on electric drive inverter reconstruction, characterized in that, The system includes a power battery, an inverter, a drive motor, and a controller. The inverter includes three IGBT bridges connected in parallel across the power battery. The drive motor includes three winding inductors, one end of which is interconnected, and the other end of each winding inductor is connected to the intermediate circuit of the three IGBT bridges, forming three connection terminals. The positive terminal of the power battery has two branches. One branch is connected to the positive terminal of the inverter via a first relay, and the other branch is connected to one end of a capacitor via a series adjustable resistor and a second relay. One or two of the connection terminals are connected to the other end of the capacitor. The controller is used to adjust the states of the first relay, the second relay, and the adjustable resistor according to the monitored temperature of the power battery to achieve switching operation between the drive circuit and the self-heating circuit. When the self-heating circuit is running, the first relay is in the off state. The current flows from the positive terminal of the power battery through another branch, passing through the adjustable resistor, the second relay, the capacitor, and then through the three winding inductors and the IGBT bridge to reach the negative terminal of the power battery, thus forming a complete self-heating circuit for the power battery.

2. The power battery self-heating system based on electrical drive inverter reconfiguration of claim 1, wherein, The negative terminal of the inverter is connected to the negative terminal of the power battery via a third relay, and the third relay is connected to the controller.

3. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 2, characterized in that, Each IGBT bridge group includes two IGBT insulated-gate transistors; the first IGBT bridge group includes a first IGBT and a fourth IGBT, the second IGBT bridge group includes a second IGBT and a fifth IGBT, and the third IGBT bridge group includes a third IGBT and a sixth IGBT; the three winding inductors of the drive motor are a first winding inductor, a second winding inductor, and a third winding inductor; the other end of the first winding inductor is connected to the intermediate circuit of the first IGBT bridge group to form a first connection terminal; The other end of the second winding inductor is connected to the intermediate circuit of the second IGBT bridge to form a second connection terminal; the other end of the third winding inductor is connected to the intermediate circuit of the third IGBT bridge to form a third connection terminal.

4. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 3, characterized in that, The other end of the capacitor is connected to the first connection terminal.

5. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 3, characterized in that, The other end of the capacitor is connected to two parallel circuits, one of which is connected to the first connection terminal and the other is connected to the second connection terminal.

6. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 4, characterized in that, When the self-heating circuit is running, the first relay is in the off state. The current flows from the positive terminal of the power battery through another branch, sequentially through the adjustable resistor, the second relay, and the capacitor, and then through the first connection terminal to the first winding inductor. The current flows out from the second winding inductor and the third winding inductor, respectively. The current flowing out from the second winding inductor flows through the second connection terminal to the fifth IGBT, and then merges with the current flowing out from the third winding inductor through the third connection terminal to the sixth IGBT, and finally flows to the negative terminal of the power battery to form a complete self-heating circuit for the power battery.

7. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 5, characterized in that, When the self-heating circuit is running, the first relay is in the off state. The current flows from the positive terminal of the power battery through another branch, passing through the adjustable resistor, the second relay, and the capacitor in sequence. Then, it flows through the first connection terminal and the second connection terminal, through the first winding inductor and the second winding inductor, and flows out from the third winding inductor. After passing through the third connection terminal and the sixth IGBT, it flows back to the negative terminal of the power battery, thus forming a complete self-heating circuit for the power battery.

8. The power battery self-heating system based on electric drive inverter reconfiguration according to claim 1, characterized in that, When the drive circuit is running, the first relay is in a closed state and the second relay is in an open state.

9. A method for self-heating a power battery using the power battery self-heating system based on electric drive inverter reconfiguration as described in any one of claims 1 to 8, characterized in that, The method includes: Obtain the initial temperature of a single power battery cell; If the initial temperature is lower than the temperature required for the drive circuit to operate, the first relay is disconnected and the second relay is closed at the same time, so that the power battery enters the self-heating charge and discharge cycle mode. Real-time monitoring of the temperature of individual battery cells during the self-heating charge-discharge cycle of the power battery; Determine whether the current temperature of the individual battery cell has reached the set temperature threshold; If the current temperature reaches the set temperature threshold, the second relay will be disconnected to stop the heating of the power battery.

10. The method according to claim 9, characterized in that, After real-time monitoring of the temperature of a single cell during the self-heating charge-discharge cycle of the power battery, the following steps are also included: Calculate the current temperature rise rate of the individual battery cell based on the monitored temperature of the individual cell; If the current temperature rise rate reaches the first threshold, the resistance value of the adjustable resistor is adjusted so that the heating power of the power battery is reduced to a preset power. If the current rate of temperature rise reaches the second threshold, the second relay is disconnected to stop the heating of the power battery.

11. The method according to claim 10, characterized in that, If the second relay becomes stuck when it is disconnected, the third relay is immediately disconnected to break the self-heating electrical circuit.

12. The method according to claim 9, characterized in that, Before the power battery enters the self-heating charge-discharge cycle, it also includes: Disconnect the second relay and keep the vehicle in the parked position; The alternating drive system operates in a first and second state to align the rotor teeth of the drive motor with the small teeth of the A-phase stator magnetic poles; the first state includes closing the first and third relays; the second state includes opening the first and third relays.

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