Battery heating system, method, apparatus and program product

Abstract

The invention relates to the technical field of batteries, in particular to a battery heating system, method, equipment and program product. The system comprises a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch and a motor. The direct current side of the three-phase full-bridge inverter is connected with the battery, and the alternating current side of the three-phase full-bridge inverter is connected with the three-phase winding of the motor. The capacitor is connected in parallel with the direct current side of the three-phase full-bridge inverter; the first end of the first switch is connected with the anode of the battery, and the second end of the first switch is connected with the first end of the second winding in the three-phase windings; a first end of the second switch is connected with a bridge arm midpoint of a second bridge arm in the three-phase full-bridge inverter, and a second end of the second switch is connected with a first end of the second winding; and the controller is used for realizing cyclic alternate charging and discharging of the battery and heating the battery. According to the invention, on the basis of ensuring efficient heating of the battery, the hardware transformation cost is reduced, and the safety of battery heating is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery heating system, method, device and program product. Background Art

[0002] In recent years, new energy vehicles powered by batteries have become increasingly common, and at the same time, the requirements for the environmental adaptability of new energy vehicles have become increasingly higher. In new energy vehicles under low temperature conditions, the low battery temperature will lead to various problems such as difficulty in charging, low discharge efficiency, and decreased cycle life. Therefore, battery heating in low temperature environments is of great significance to the efficient operation of batteries. The existing technology provides a battery heating method that realizes the charging and discharging between the battery and the capacitor through a motor and a controller to achieve pulse heating. However, this method requires the neutral point to be connected from the vehicle load motor to the battery, which requires a major structural change to the motor, which not only increases the cost of hardware modification, but also increases the risk of damage to the motor and battery, and reduces the efficiency of battery heating. Summary of the Invention

[0003] Based on the above-mentioned defects and shortcomings of the existing technology, the present application proposes a battery heating system, method, device and program product, which can reduce the hardware modification cost and improve the safety of battery heating while ensuring efficient heating of the battery.

[0004] According to a first aspect of the present application, a battery heating system is provided, comprising a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch, and a motor; the DC side of the three-phase full-bridge inverter is connected to a battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; a first end of the first switch is connected to the positive electrode of the battery, and a second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding, and a third winding, and the second end of the first winding, the second end of the second winding, and the second end of the third winding are connected in common; a first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter, and a second end of the second switch is connected to the first end of the second winding; the controller is configured to, when the first switch is closed and the second switch is open, control the first and third bridge arms of the three-phase full-bridge inverter to charge and discharge the capacitor and the battery to heat the battery.

[0005] According to the battery heating system provided in the first aspect of the present application, the controller is further configured to control the switch tubes in the three-phase full-bridge inverter to provide AC power to the motor when the first switch is disconnected and the second switch is closed.

[0006] The battery heating system provided according to the first aspect of the present application also includes a first current sensor and a second current sensor; the first end of the first current sensor is connected to the midpoint of the first bridge arm in the three-phase full-bridge inverter, and the second end of the first current sensor is connected to the first end of the first winding; the first end of the second current sensor is connected to the midpoint of the third bridge arm in the three-phase full-bridge inverter, and the second end of the second current sensor is connected to the first end of the third winding; the controller is used to obtain the first current value detected by the first current sensor and the second current value detected by the second current sensor when the first switch is closed and the second switch is open, and control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter based on the target current value, the first current value and the second current value.

[0007] According to the battery heating system provided in the first aspect of the present application, the controller is specifically used to perform proportional-integral-differential operations based on the target current value, the first current value and the second current value to obtain a first duty cycle and a second duty cycle when the first switch is closed and the second switch is open, control the on and off of the switch tube in the first bridge arm based on the first duty cycle, and control the on and off of the switch tube in the third bridge arm based on the second duty cycle.

[0008] According to the battery heating system provided in the first aspect of the present application, the controller is further configured to control the switch tube in the second bridge arm to turn off.

[0009] According to the battery heating system provided in the first aspect of the present application, the controller is further used to obtain real-time current values ​​in the first bridge arm and the third bridge arm if battery heating stop information is received when the first switch is closed and the second switch is disconnected, and if it is determined based on the real-time current value that the capacitor is in a discharging state, or if the cumulative time for starting the current limitation between the battery and the capacitor in the charging state reaches a time threshold when the battery heating stop information is received, then control the switch tubes in the first bridge arm and the third bridge arm to turn off.

[0010] According to the battery heating system provided in the first aspect of the present application, the controller is further configured to, when the first switch is closed and the second switch is open, upon receiving the battery heating stop information, if it is determined based on the real-time current value that the capacitor is in a charging state, limit the target current value of charging and discharging between the battery and the capacitor to zero, and start counting the cumulative duration of the restriction.

[0011] According to a second aspect of the present application, a battery heating method is provided, which is applied to a controller in a battery heating system; the battery heating system includes the controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch, and a motor; the DC side of the three-phase full-bridge inverter is connected to a battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; a first end of the first switch is connected to the positive electrode of the battery, and a second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding, and a third winding, and the second end of the first winding, the second end of the second winding, and the second end of the third winding are connected in common; the first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter; the method includes: when the first switch is closed and the second switch is open, controlling the first and third bridge arms of the three-phase full-bridge inverter to charge and discharge the capacitor and the battery to heat the battery.

[0012] According to a third aspect of the present application, an electronic device is provided, comprising: a memory and a processor; the memory is connected to the processor and is used to store a program; the processor is used to implement the battery heating method as described in the second aspect by running the program in the memory.

[0013] According to a fourth aspect of the present application, a computer program product is provided, comprising computer program instructions; when the computer program instructions are executed by a processor, the processor is enabled to perform the battery heating method as described in the second aspect.

[0014] In the present application, the battery heating system includes a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch and a motor; the DC side of the three-phase full-bridge inverter is connected to the battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; the first end of the first switch is connected to the positive pole of the battery, and the second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding and a third winding, and the second end of the first winding, the second end of the second winding and the second end of the third winding are connected in common; the first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter, and the second end of the second switch is connected to the first end of the second winding; the controller is used to control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter to charge and discharge the capacitor and the battery when the first switch is closed and the second switch is open, so as to heat the battery. In the above solution, the three-phase winding in the motor acts as an inductor, and the inductor and the capacitor act together as energy storage elements to realize charging and discharging between the capacitor and the battery, and achieve the purpose of efficient heating of the battery based on the battery's own impedance. In addition, in the above solution, compared with the solution of extracting the neutral point from the motor, the present application only realizes the state switching of the system through the first switch and the second switch, which requires less modification to the hardware system and reduces the cost of hardware modification. In summary, the solution provided by the present application can reduce the cost of hardware modification and improve the safety of battery heating on the basis of ensuring efficient heating of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0016] Figure 1 This is one of the structural connection diagrams of a battery heating system provided in an embodiment of the present application.

[0017] Figure 2 A schematic diagram of the principle of applying a battery heating system provided in an embodiment of the present application to battery heating.

[0018] Figure 3 A schematic diagram of the principle of battery discharging based on a battery heating system provided in an embodiment of the present application.

[0019] Figure 4 A schematic diagram of the principle of battery charging based on a battery heating system provided in an embodiment of the present application.

[0020] Figure 5A schematic diagram of the principle of a battery heating system provided in an embodiment of the present application for power provision.

[0021] Figure 6 This is the second structural connection diagram of a battery heating system provided in an embodiment of the present application.

[0022] Figure 7 A schematic diagram of the software control principle for battery heating provided in an embodiment of the present application.

[0023] Figure 8 A control logic diagram of a battery heating system provided in an embodiment of the present application applied to a vehicle.

[0024] Figure 9 A schematic diagram of a software control principle for preventing capacitor damage provided in an embodiment of the present application.

[0025] Figure 10 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0026] Reference numerals: K1 - first switch; K2 - second switch; K3 - third switch; K4 - fourth switch; C1 - capacitor; R1 - resistor; S1 - first switch tube; S2 - second switch tube; S3 - third switch tube; S4 - fourth switch tube; S5 - fifth switch tube; S6 - sixth switch tube; L1 - first winding; L2 - second winding; L3 - third winding; A1 - first current sensor; A2 - second current sensor. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] Exemplary Systems In response to the problems existing in the prior art of battery heating, the present application provides a battery heating system.

[0029] In one embodiment, Figure 1 As shown, the battery heating system includes a controller (not shown in Figure 1), a three-phase full-bridge inverter 101, a capacitor C1, a first switch K1, a second switch K2, and a motor 102. The DC side of the three-phase full-bridge inverter 101 is connected to a battery, and the AC side of the three-phase full-bridge inverter 101 is respectively connected to the three-phase windings of the motor 102; the capacitor C1 is connected in parallel to the DC side of the three-phase full-bridge inverter 101; a first end of the first switch K1 is connected to the positive electrode of the battery, and a second end of the first switch K1 is connected to the first end of the second winding L2 in the three-phase winding, wherein the three-phase winding includes a first winding L1, a second winding L2, and a third winding L3, and the second end of the first winding L1, the second end of the second winding L2, and the second end of the third winding L3 are connected in common; a first end of the second switch K2 is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter 101, and a second end of the second switch is connected to the first end of the second winding. The controller is configured to control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter 101 to charge and discharge the capacitor C1 and the battery to heat the battery when the first switch K1 is closed and the second switch K2 is open.

[0030] In this embodiment, the three-phase full-bridge inverter 101 includes six switching transistors, which are respectively represented by a first switching transistor S1, a second switching transistor S2, a third switching transistor S3, a fourth switching transistor S4, a fifth switching transistor S5, and a sixth switching transistor S6. The first switching transistor S1 and the fourth switching transistor S4 form a first bridge arm, the second switching transistor S2 and the fifth switching transistor S5 form a second bridge arm, and the third switching transistor S3 and the sixth switching transistor S6 form a third bridge arm. Optionally, the switching transistors in the three-phase full-bridge inverter can be insulated gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), or any other switching transistor device or switching transistor module suitable for an inverter. A capacitor is connected in parallel on the DC side of the three-phase full-bridge inverter 101. Optionally, the capacitor can be a thin-film capacitor. Thin-film capacitors offer advantages such as high frequency, low loss, self-healing properties, long life, and wide temperature stability, making them particularly suitable for use in the fields of new energy and automotive electronics. It should be noted that the specific specifications of capacitor C1, such as the capacitance value, are predetermined based on actual conditions and needs, and the scope of protection of this application is not limited to the specific specifications of capacitor C1.

[0031] In this embodiment, the motor 102 includes three-phase windings, namely, a first winding L1, a second winding L2, and a third winding L3. The first winding L1, the second winding L2, and the third winding L3 correspond to the three phases according to actual conditions and needs. For example, the first winding L1, the second winding L2, and the third winding L3 correspond to the U phase, the V phase, and the W phase, respectively. The first end of the first winding L1 is connected to the midpoint of the first bridge arm. A second switch K2 is connected in series between the first end of the second winding L2 and the midpoint of the second bridge arm. Specifically, the first end of the second switch K2 is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter 101, and the second end of the second switch K2 is connected to the first end of the second winding L2. The first end of the third winding L3 is connected to the midpoint of the third bridge arm. The second ends of the first winding L1, the second ends of the second winding L2, and the second ends of the third winding L3 are connected together to form a neutral point.

[0032] In this embodiment, Figure 1 The battery in the figure refers to the battery to be heated. A first switch K1 is added between the battery and the second winding L2, that is, a first end of the first switch K1 is connected to the positive electrode of the battery, and a second end of the first switch K1 is connected to the first end of the second winding L2.

[0033] In this embodiment, to ensure the battery's ability to properly output power to the motor, a third switch K3 is connected in series between the battery's positive electrode and the DC side of the three-phase full-bridge inverter 101 as a main power switch. Specifically, the first end of the third switch K3 is connected to the battery's positive electrode, and the second end of the third switch K3 is connected to the DC input of the first switching transistor S1. A fourth switch K4 is also connected in series between the battery's positive electrode and the DC side of the three-phase full-bridge inverter 101 as a pre-charge bypass switch, along with a series resistor R1 as a pre-charge resistor. Specifically, the first end of the fourth switch K4 is connected to the battery's positive electrode, the second end of the fourth switch K4 is connected to the first end of the resistor R1, and the second end of the resistor R1 is connected to the DC input of the first switching transistor S1. When the three-phase full-bridge inverter 101 is used to normally output power to the motor (i.e., when the first switch K1 is disconnected and the second switch K2 is closed), the third switch K3 acts as the main power switch to control the on / off of the high-voltage DC bus main circuit; the resistor R1 limits the initial charging current of the battery to the capacitor C1 to prevent instantaneous high current shock from damaging the device; the fourth switch K4 acts as a pre-charge bypass switch to short-circuit the resistor R1 after pre-charging is completed, eliminating resistance loss and establishing a low-voltage drop main power path. Specifically, when the battery normally outputs power to the motor, during the pre-charge phase, the third switch K3 is disconnected and the fourth switch K4 is closed, and the battery slowly charges the capacitor C1 through the resistor R1; after the pre-charge is completed, when the voltage of the capacitor C1 approaches the battery voltage, the third switch K3 is disconnected and closed, R1 is bypassed, and the system enters full-power operation.

[0034] Optionally, the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 mentioned above can be relays; any one of the relays can be controlled to be closed or opened by the controller mentioned above, or can be controlled to be closed or opened by other control modules or control logic according to actual conditions and needs.

[0035] In this embodiment, the first switch K1 and the second switch K2 serve as control switches of the AC heating control circuit to achieve Figure 1 The electrical system shown is switching between normal power output function and battery AC heating function. If the battery needs to be heated, the first switch K1 is controlled to be closed and the second switch K2 is opened, as shown in FIG. Figure 2 As shown, an equivalent electrical connection diagram is shown with the first switch K1 closed and the second switch K2 open, achieving AC heating of the battery. The controller controls the first and third bridge arms of the three-phase full-bridge inverter 101 to alternately charge and discharge capacitor C1 and the battery to heat the battery.

[0036] In this embodiment, the capacitor C1 is first precharged through the third switch K3 and the fourth switch K4 to make the voltage across the battery equal to the voltage across the capacitor C1. After the precharge is completed, the first switch K1 is controlled to close and the second switch K2 is opened. The controller controls the switch tubes in the first bridge arm and the third bridge arm, such as Figure 3 As shown, based on the controller, capacitor C1, the first bridge arm, the third bridge arm and the three-phase winding, a boost chopper circuit is formed to control the battery discharge (i.e., the capacitor C1 is charged). Specifically, when current flows out of the battery, the current passes through the three-phase winding in the motor 102, and then passes through the first bridge arm and the third bridge arm to charge the capacitor C1. Figure 4 As shown, a buck chopper circuit is formed based on the controller, capacitor C1, the first bridge arm, the third bridge arm, and the three-phase winding to control the discharge of capacitor C1 (i.e., charging the battery). Specifically, current flows from capacitor C1, passes through the first and third bridge arms, and then through the three-phase winding of motor 102 to charge the battery. Due to the internal resistance of the battery, when capacitor C1 and the battery alternate between charging and discharging, current alternates between flowing out and flowing into the battery. The internal resistance of the battery generates heat, which in turn increases the battery temperature, achieving the purpose of battery heating.

[0037] In one embodiment, the controller is further configured to control the switches in the three-phase full-bridge inverter 101 to provide AC power to the motor 102 when the first switch K1 is disconnected and the second switch K2 is closed.

[0038] In this embodiment, if the battery does not need to be heated or the battery heating is completed, the first switch K1 is controlled to be closed and the second switch K2 is controlled to be open. Figure 5As shown, by controlling the on and off of the third switch K3 and the fourth switch K4, and controlling the on and off of each switch tube in the three-phase full-bridge inverter 101, the direct current output by the battery is converted into the alternating current required by the motor 102, and the battery normally provides power to the motor 102.

[0039] In this embodiment, by controlling the closing and opening of the first switch K1 and the second switch K2, flexible switching between normal motor output power and battery AC heating is achieved. Before and after switching, the capacitor C1, the three-phase full-bridge inverter 101 and the motor winding are reused, thereby avoiding the addition of redundant components as much as possible, improving the utilization rate of various hardware components, and reducing the overall hardware cost. Moreover, more reuse of components and less hardware modification can reduce the risk of hardware damage and improve the safety and reliability of the overall system.

[0040] In one embodiment, the battery heating system further includes a first current sensor A1 and a second current sensor A2. A first end of the first current sensor A1 is connected to the midpoint of the first bridge arm of the three-phase full-bridge inverter 101, and a second end of the first current sensor A1 is connected to the first end of the first winding L1. A first end of the second current sensor A2 is connected to the midpoint of the third bridge arm of the three-phase full-bridge inverter 101, and a second end of the second current sensor A2 is connected to the first end of the third winding L3. A controller is configured to obtain a first current value detected by the first current sensor A1 and a second current value detected by the second current sensor A2 when the first switch K1 is closed and the second switch K2 is open, and to control the first and third bridge arms of the three-phase full-bridge inverter 101 based on the target current value, the first current value, and the second current value.

[0041] In this embodiment, in order to improve the control accuracy of the AC heating process, Figure 6 As shown, a first current sensor A1 is connected in series between the first bridge arm and the first winding L1 to detect the first current value flowing through the first bridge arm and the first winding L1 in real time; and a second current sensor A2 is connected in series between the third bridge arm and the third winding L3 to detect the second current value flowing through the third bridge arm and the third winding L3 in real time. Optionally, the first current sensor A1 and the second current sensor A2 can select specific sensor types according to actual conditions and needs, such as Hall sensors. The target current value is the target value of the charging and discharging current between the battery and the capacitor C1. The target current value is set in advance according to actual conditions and heating requirements. For example, the target current value corresponds to the instantaneous value of the sinusoidal current waveform, and the change of the target current value conforms to the sinusoidal waveform. The current waveform formula corresponding to the target current value is as follows: I = Asin(2*π*f*t); Wherein, I represents the instantaneous target current value, A represents the maximum current amplitude of the sine wave, f represents the current frequency, t represents the time, represents the circular constant, and sin represents the sine function.

[0042] In this embodiment, the first current value and the second current value are synchronized to the controller, and the controller controls the switching tubes in the first bridge arm and the third bridge arm based on the target current value, the first current value and the second current value, so that the current flowing through the first bridge arm and the third bridge arm is closer to the target current value required for actual heating, thereby improving the AC heating effect.

[0043] In one embodiment, the controller is specifically configured to, in a case where the first switch K1 is closed and the second switch K2 is open, perform proportional-integral-derivative operation based on the target current value, the first current value and the second current value to obtain a first duty ratio and a second duty ratio, control the on-off of the switching tube in the first bridge arm based on the first duty ratio, and control the on-off of the switching tube in the third bridge arm based on the second duty ratio.

[0044] In this embodiment, the controller controls the switching tubes in the first bridge arm and the third bridge arm by using a proportional-integral-derivative (PID) algorithm and a duty ratio adjustment method. Specifically, after the controller obtains the first current value and the second current value actually flowing through the circuit, the controller calculates the current difference between the first current value and the target current value and the current difference between the second current value and the target current value, takes the current difference as the input of the PID algorithm, performs PID operation on the current difference, and dynamically outputs the pulse width modulation (PWM) duty ratio corresponding to the first bridge arm and the third bridge arm, i.e., the first duty ratio corresponding to the first bridge arm and the second duty ratio corresponding to the third bridge arm. The on-off duration of the switching tube in the first bridge arm is dynamically controlled based on the first duty ratio, and the on-off duration of the switching tube in the third bridge arm is dynamically controlled based on the second duty ratio. By adjusting the first duty ratio and the second duty ratio, the effective value of the voltage output by the first bridge arm and the third bridge arm is changed, thereby adjusting the current value flowing through the first bridge arm and the third bridge arm. The actual first current value and the second current value are closer to the target current value required for heating, thereby improving the battery heating effect.

[0045] In one embodiment, the controller is further configured to control the switching tube in the second bridge arm to be off.

[0046] In this embodiment, during the battery heating process, the switching tubes in the second bridge arm are all in the off state, for example, Figure 2As shown, the controller controls the on / off of the first switch tube S1 and the fourth switch tube S4 based on a first duty cycle, and controls the on / off of the third switch tube S3 and the sixth switch tube S6 based on a second duty cycle. At the same time, the second switch tube S2 and the fifth switch tube S5 are in the off state during the entire heating process to avoid forming a redundant loop, thereby improving the accuracy of current path control and the battery heating efficiency; avoiding the formation of a direct path between the second switch tube S2 and the fifth switch tube S5, which would cause a DC bus short circuit and burn out the components, thereby improving system safety; reducing the adjustment complexity of the switch tube, avoiding unnecessary switching actions, and extending the service life of the switch tube.

[0047] In one embodiment, for example, the second winding is a V-phase winding, the first winding and the first bridge arm correspond to the U-phase, the third winding and the third bridge arm correspond to the W-phase, the second switch K2 is connected in series with the V-phase winding, the first current sensor A1 is connected in series with the U-phase winding, and the second current sensor A2 is connected in series with the W-phase winding. In the battery heating state, Figure 7 As shown, the charge and discharge current between the battery and the capacitor C1 is pre-set to be a sinusoidal current, and the target current value is the instantaneous value of the sinusoidal current. The first current sensor A1 collects the real-time first current value of the U phase, and the second current sensor A2 collects the real-time second current value of the W phase. The controller adopts a PID algorithm to calculate the current difference between the U phase and the W phase based on the target current value, the first current value and the second current value, performs PID operation based on the current difference, and outputs the first duty cycle required for the U phase and the second duty cycle required for the W phase. The controller controls the switch tube in the second bridge arm corresponding to the V phase to remain in the off state, adjusts the conduction and shutdown of the switch tube in the first bridge arm based on the first duty cycle, and adjusts the conduction and shutdown of the switch tube in the third bridge arm based on the second duty cycle, so as to realize the cyclic charge and discharge of the battery, thereby achieving the purpose of battery AC heating.

[0048] In one embodiment, when the first switch K1 is closed and the second switch K2 is open, if heating of the capacitor C1 suddenly needs to be stopped during charging (i.e., battery discharging), if the controller directly controls the switching tubes in the three-phase full-bridge inverter 101 to be turned off, then since the battery is charging the capacitor C1 at this time, and the current flowing through the three-phase winding of the motor 102 serving as an inductor cannot change suddenly, the capacitor C1 can continue to be charged through the freewheeling diodes corresponding to the first switching tube S1 in the first bridge arm and the third switching tube S3 in the third bridge arm, resulting in a greater risk of overvoltage damage to the capacitor C1.

[0049] In this embodiment, in order to avoid the risk of overvoltage damage to the capacitor C1 caused by a sudden shutdown during the charging process of the capacitor C1, the controller is further configured to, when the first switch K1 is closed and the second switch K2 is disconnected, obtain real-time current values ​​in the first bridge arm and the third bridge arm if a battery heating stop message is received; if it is determined based on the real-time current value that the capacitor C1 is in a discharging state, or if the cumulative time for starting the current limiting between the battery and the capacitor C1 in the charging state when the battery heating stop message is received reaches a time threshold, control the switch tubes in the first bridge arm and the third bridge arm to turn off.

[0050] In this embodiment, battery heating stop information refers to information indicating the cessation of the battery heating process, such as system shutdown fault information, system shutdown instructions, etc. When the first switch K1 is closed and the second switch K2 is open, if the battery heating stop information is received, the system first determines whether the capacitor C1 is in a discharging or charging state based on the real-time current values ​​in the first and third bridge arms. If the capacitor C1 is in a discharging state (the battery is in a charging state), the voltage of the capacitor C1 is continuously decreasing, and there is no risk of overvoltage damage. The switches in the first and third bridge arms can then be turned off. If the capacitor C1 is in a charging state (the battery is in a discharging state), the accumulated limit duration is compared with a duration threshold to determine whether the current limiting between the battery and capacitor C1 has reached a limit that can prevent overvoltage damage to the capacitor C1. If the accumulated limit duration reaches the duration threshold, this indicates that the current limiting between the battery and capacitor C1 has sufficiently limited the freewheeling charging of the capacitor C1. The switches in the first and third bridge arms can then be turned off. It should be noted that the duration threshold can be set in advance based on experimental data, empirical data and actual needs, and the protection scope of this application is not limited to the specific value of the duration threshold.

[0051] In one embodiment, the controller is further configured to, when the first switch K1 is closed and the second switch K2 is open, limit the target current value of charging and discharging between the battery and the capacitor C1 to zero and start counting the cumulative time limit when receiving the battery heating stop information if it is determined based on the real-time current value that the capacitor C1 is in a charging state.

[0052] In this embodiment, when the first switch K1 is closed and the second switch K2 is open, upon receiving the battery heating stop information, if it is determined that the capacitor C1 is in the charging state based on the real-time current value, the target current value of the charging and discharging between the battery and the capacitor C1 is immediately set to zero, so as to limit the actual current value in the first bridge arm and the third bridge arm and reduce the actual current value to zero. The current reduction process needs a process, so upon receiving the battery heating stop information, the limitation accumulation time is immediately started. If the capacitor C1 is no longer charged during the limitation process, or the limitation accumulation time reaches the time threshold, the switch tube in the first bridge arm and the third bridge arm is turned off, and the limitation accumulation time is reset to zero. By limiting the accumulation time, other safety risks caused by the long duration of the current limitation process are avoided, and the safety is improved.

[0053] In a specific embodiment, the battery heating system is configured in a vehicle, wherein the battery is a power battery of the vehicle, the motor 102 is a load motor on the vehicle, and the three-phase full-bridge inverter 101 is a three-phase full-bridge inverter configured on the vehicle to normally provide power for the load motor of the vehicle.

[0054] In this embodiment, as shown in Figure 8 The control logic of the battery heating system applied to the vehicle is as follows: Step 801: The vehicle is in neutral gear to ensure that the motor 102 can rotate; Step 802: Motor pre-positioning is performed, that is, the rotor of the motor 102 is controlled to rotate so that two-phase currents in the three-phase current are the same, and the motor is in a zero-torque output state. For example, when the second switch K2 is connected in series with the V-phase winding, the rotor of the motor 102 is rotated to a position of 120°, and the U / W two-phase currents are the same. After the pre-positioning is completed, the rotor of the motor 102 no longer rotates, so that two-phase currents in the three-phase current are the same; Step 803: The controller is switched to the battery heating mode, and the first switch K1 is closed and the second switch K2 is open; Optionally, the controller in the battery heating system is a motor controller (MCU) on the vehicle, which is mainly used for controlling the switch tube in the three-phase full-bridge inverter 101. Optionally, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 in the battery heating system are all controlled by a vehicle controller (VCU) on the vehicle. The motor controller is pre-configured with a torque model, a speed model, a battery heating mode, and other vehicle models, and when it is necessary to heat the power battery of the vehicle, the motor controller is switched to the battery heating mode. In the battery heating mode, the preset program related to battery heating can be called to realize the control logic required in the battery heating process. In step 804, the controller controls the switches in the first and third bridge arms to implement boost chopper to discharge the battery (i.e., charge the capacitor). The controller monitors the actual current values ​​(including the first and second current values) in the first and third bridge arms using the first current sensor A1 and the second current sensor A2. If the actual current value meets the target current value of a sinusoidal current, the controller determines that the actual current value during the battery discharge (i.e., capacitor charging) process is a forward current value. In step 805, the controller controls the switches in the first and third bridge arms to implement buck chopper and charge the battery (i.e., discharge the capacitor). The controller monitors the actual current values ​​in the first and third bridge arms based on the first current sensor A1 and the second current sensor A2. If the actual current value meets the target current value of the sinusoidal current, the controller determines that the actual current value during the battery discharge (i.e., capacitor charging) process is a negative current value.

[0055] In the above process, step 804 and step 805 are executed alternately during the battery heating process, thereby forming long-term monitoring and real-time regulation of the actual current value, thereby improving the safety of the battery heating process.

[0056] In this embodiment, in order to avoid the capacitor C1 being damaged by overvoltage due to sudden cessation of heating during battery discharge (i.e., capacitor charging), Figure 9 As shown, the controller implements the following control logic: Step 901: The MCU receives a battery heating instruction sent by the vehicle; Step 902: The MCU switches to the battery heating mode and performs AC heating on the battery by cyclically charging and discharging the battery. Step 903, determining whether the battery heating stop information is received, if so, executing step 904, if not, executing step 902; Optionally, the battery heating stop information includes a stop heating instruction sent by the VCU, and also includes a fault shutdown information generated by the MCU itself; Step 904: Detecting actual current values ​​in the first bridge arm and the third bridge arm in real time; Step 905 , judging whether the capacitor C1 is in a charging state (the battery is in a discharging state) based on the actual current value, if so, executing step 906 , if not, executing step 908 ; Step 906 , limiting the target current value of charging and discharging between the battery and the capacitor C1 to zero, and calculating the cumulative duration of the limitation; When counting the cumulative time limit, the initial value of the cumulative time limit is 0; Step 907, determine whether the cumulative restriction duration reaches the duration threshold, if so, execute step 908, if not, execute step 905; Step 908: Control the switch tubes in the first bridge arm and the third bridge arm to turn off.

[0057] When executing step 908, if the cumulative limit time is not zero, the cumulative limit time is cleared.

[0058] In the present application, the battery heating system includes a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch and a motor; the DC side of the three-phase full-bridge inverter is connected to the battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; the first end of the first switch is connected to the positive pole of the battery, and the second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding and a third winding, and the second end of the first winding, the second end of the second winding and the second end of the third winding are connected in common; the first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter, and the second end of the second switch is connected to the first end of the second winding; the controller is used to control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter to charge and discharge the capacitor and the battery when the first switch is closed and the second switch is open, so as to heat the battery. In the above solution, the three-phase winding in the motor acts as an inductor, and the inductor and the capacitor act together as energy storage elements to realize charging and discharging between the capacitor and the battery, and achieve the purpose of efficient heating of the battery based on the battery's own impedance. In addition, in the above solution, compared with the solution of extracting the neutral point from the motor, the present application only realizes the state switching of the system through the first switch and the second switch, which requires less modification to the hardware system and reduces the cost of hardware modification. In summary, the solution provided by the present application can reduce the cost of hardware modification and improve the safety of battery heating on the basis of ensuring efficient heating of the battery.

[0059] Furthermore, the solution provided in this application requires minimal hardware modification, primarily by modifying the controller's software control algorithm to achieve AC battery heating. Furthermore, when the battery heating system needs to be suddenly shut down, the actual current direction is determined based on the real-time current value, avoiding capacitor overvoltage damage caused by sudden shutdown while the capacitor is charging (i.e., battery discharging). By limiting the target current value and calculating the cumulative time limit, the current is controlled before the switch is shut down, ensuring timely system shutdown while improving device safety.

[0060] Exemplary Methods Correspondingly, an embodiment of the present application also provides a battery heating method, which is applied to a controller in a battery heating system; the battery heating system includes a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch and a motor; the DC side of the three-phase full-bridge inverter is connected to the battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; the first end of the first switch is connected to the positive pole of the battery, and the second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding and a third winding, and the second end of the first winding, the second end of the second winding and the second end of the third winding are connected in common; the first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter.

[0061] The battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, controlling the first bridge arm and the third bridge arm in the three-phase full-bridge inverter to charge and discharge the capacitor and the battery to heat the battery.

[0062] In one embodiment, the battery heating method implemented in the controller further includes: controlling switches in the three-phase full-bridge inverter to provide AC power to the motor when the first switch is open and the second switch is closed.

[0063] In one embodiment, the battery heating system further includes a first current sensor and a second current sensor; the first end of the first current sensor is connected to the midpoint of the first bridge arm in the three-phase full-bridge inverter, and the second end of the first current sensor is connected to the first end of the first winding; the first end of the second current sensor is connected to the midpoint of the third bridge arm in the three-phase full-bridge inverter, and the second end of the second current sensor is connected to the first end of the third winding.

[0064] The battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, obtaining a first current value detected by a first current sensor and obtaining a second current value detected by a second current sensor, and controlling the first bridge arm and the third bridge arm in the three-phase full-bridge inverter based on the target current value, the first current value, and the second current value.

[0065] In one embodiment, a battery heating method implemented in a controller includes: when a first switch is closed and a second switch is open, performing a proportional-integral-differential operation based on a target current value, a first current value, and a second current value to obtain a first duty cycle and a second duty cycle; controlling the on-off of a switch tube in a first bridge arm based on the first duty cycle; and controlling the on-off of a switch tube in a third bridge arm based on the second duty cycle.

[0066] In one embodiment, the battery heating method implemented in the controller includes: controlling the switch tube in the second bridge arm to turn off.

[0067] In one embodiment, a battery heating method implemented in a controller includes: when the first switch is closed and the second switch is open, if battery heating stop information is received, obtaining real-time current values ​​in the first bridge arm and the third bridge arm; if it is determined based on the real-time current value that the capacitor is in a discharging state, or if the cumulative time for initiating current limiting between the battery and the capacitor when the battery heating stop information is received reaches a time threshold when the capacitor is in a charging state, controlling the switch tubes in the first bridge arm and the third bridge arm to turn off.

[0068] In one embodiment, the battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, when the battery heating stop information is received, if it is determined based on the real-time current value that the capacitor is in a charging state, then the target current value of the charging and discharging between the battery and the capacitor is limited to zero, and the cumulative time of the limitation is started to be counted.

[0069] The battery heating method provided in this embodiment shares the same concept as the battery heating system provided in the aforementioned embodiments of this application. It can be implemented in the controller of the battery heating system provided in any of the aforementioned embodiments of this application, and has the corresponding beneficial effects of implementing the technical solution of the battery heating system. For technical details not fully described in this embodiment, please refer to the specific processing content of the battery heating method provided in the aforementioned embodiments of this application, and will not be repeated here.

[0070] Exemplary electronic devices The present application also provides an electronic device, such as Figure 10 As shown, the electronic device includes: a memory 1000 and a processor 1001.

[0071] The memory 1000 is connected to the processor 1001 and is used to store programs.

[0072] The processor 1001 is configured to implement the battery heating method in the above embodiment by running the program stored in the memory 1000 .

[0073] Specifically, the electronic device may further include: a communication interface 1002 , an input device 1003 , an output device 1004 and a bus 1005 .

[0074] The processor 1001, the memory 1000, the communication interface 1002, the input device 1003 and the output device 1004 are interconnected via a bus. Bus 1005 may include a pathway for transferring information between various components of the computer system.

[0075] Processor 1001 can be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, or the like. It can also be an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the solution of the present invention. It can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component.

[0076] The processor 1001 may include a main processor, and may also include a baseband chip, a modem, etc.

[0077] Memory 1000 stores a program for executing the technical solution of the present invention and may also store an operating system and other key services. Specifically, the program may include program code, which includes computer operating instructions. More specifically, memory 1000 may include read-only memory (ROM), other types of static storage devices capable of storing static information and instructions, random access memory (RAM), other types of dynamic storage devices capable of storing information and instructions, disk storage, flash memory, and the like.

[0078] The input device 1003 may include a device for receiving data and information input by a user, such as a keyboard, a mouse, a camera, a scanner, a light pen, a voice input device, a touch screen, a pedometer, or a gravity sensor.

[0079] Output device 1004 may include a device that allows information to be output to a user, such as a display screen, a printer, a speaker, etc.

[0080] The communication interface 1002 may include any transceiver or similar device for communicating with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0081] The processor 1001 executes the program stored in the memory 1000 and calls other devices to implement the various steps of the battery heating method provided in the above embodiments of the present application.

[0082] Exemplary computer program products and storage media In addition to the above-mentioned method and device, the embodiment of the present application may also be a computer program product, which includes computer program instructions. When the computer program instructions are executed by a processor, the processor executes the steps of the battery heating method described in the embodiment of the present application.

[0083] The computer program product may be written in any combination of one or more programming languages ​​to implement the program code for performing the operations of the embodiments of the present application, including object-oriented programming languages ​​such as Java, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0084] In addition, the embodiment of the present application may also be a storage medium on which a computer program is stored, and the computer program is used by a processor to execute the steps of the battery heating method described in the embodiment of the present application.

[0085] For the sake of simplicity, the aforementioned method embodiments are described as a series of action combinations. However, those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0086] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similarities between the various embodiments can be referred to in conjunction with each other. For device embodiments, since they are generally similar to method embodiments, their description is relatively simple, and for relevant details, reference can be made to the description of the method embodiments.

[0087] The steps in the methods of each embodiment of the present application can be adjusted in sequence, merged, and deleted according to actual needs, and the technical features recorded in each embodiment can be replaced or combined.

[0088] The modules and sub-modules in the devices and terminals provided in the various embodiments of the present application can be merged, divided, and deleted according to actual needs.

[0089] In the several embodiments provided in this application, it should be understood that the disclosed terminals, devices, and methods can be implemented in other ways. For example, the terminal embodiments described above are merely illustrative. For example, the division of modules or submodules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple submodules or modules can be combined or integrated into another module, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or module, which can be electrical, mechanical or other forms.

[0090] The modules or submodules described as separate components may or may not be physically separate, and the components of the modules or submodules may or may not be physical modules or submodules, that is, they may be located in one place or distributed across multiple network modules or submodules. Some or all of the modules or submodules may be selected to achieve the purpose of this embodiment according to actual needs.

[0091] In addition, each functional module or submodule in each embodiment of the present application may be integrated into a processing module, or each module or submodule may exist physically separately, or two or more modules or submodules may be integrated into a single module. The above-mentioned integrated modules or submodules may be implemented in the form of hardware or software functional modules or submodules.

[0092] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0093] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, software executed by a processor, or a combination of the two. The software may be stored in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0094] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0095] The above description of the disclosed embodiments will enable those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is to be construed in the widest manner consistent with the principles and novel features disclosed herein.

Claims

1. A battery heating system, characterized in that: It includes a controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch and a motor; The DC side of the three-phase full-bridge inverter is connected to a battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; The capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; A first end of the first switch is connected to the positive electrode of the battery, and a second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding includes a first winding, a second winding, and a third winding, and the second end of the first winding, the second end of the second winding, and the second end of the third winding are connected in common; A first end of the second switch is connected to a midpoint of a second bridge arm in the three-phase full-bridge inverter, and a second end of the second switch is connected to a first end of the second winding; The controller is used to control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter to charge and discharge the capacitor and the battery to heat the battery when the first switch is closed and the second switch is open.

2. The battery heating system according to claim 1, characterized in that: The controller is further configured to control the switch tubes in the three-phase full-bridge inverter to provide AC power to the motor when the first switch is disconnected and the second switch is closed.

3. The battery heating system according to claim 1, characterized in that: Also included is a first current sensor and a second current sensor; A first end of the first current sensor is connected to a midpoint of a first bridge arm in the three-phase full-bridge inverter, and a second end of the first current sensor is connected to a first end of the first winding; The first end of the second current sensor is connected to the midpoint of the third bridge arm of the three-phase full-bridge inverter, and the second end of the second current sensor is connected to the first end of the third winding; The controller is used to obtain a first current value detected by the first current sensor and a second current value detected by the second current sensor when the first switch is closed and the second switch is open, and to control the first bridge arm and the third bridge arm in the three-phase full-bridge inverter based on the target current value, the first current value and the second current value.

4. The battery heating system according to claim 3, characterized in that: The controller is specifically used to perform proportional-integral-differential operations based on the target current value, the first current value, and the second current value to obtain a first duty cycle and a second duty cycle when the first switch is closed and the second switch is open, control the on and off of the switch tube in the first bridge arm based on the first duty cycle, and control the on and off of the switch tube in the third bridge arm based on the second duty cycle.

5. The battery heating system according to claim 3, characterized in that: The controller is further configured to control the switch in the second bridge arm to turn off.

6. The battery heating system according to claim 1, characterized in that: The controller is further configured to, when the first switch is closed and the second switch is open, obtain real-time current values ​​in the first bridge arm and the third bridge arm if battery heating stop information is received; and control the switch tubes in the first bridge arm and the third bridge arm to turn off if it is determined based on the real-time current value that the capacitor is in a discharging state, or if the cumulative duration of the current limitation between the battery and the capacitor initiated in a charging state reaches a duration threshold when the battery heating stop information is received.

7. The battery heating system according to claim 6, characterized in that: The controller is further configured to, when the first switch is closed and the second switch is open, limit the target current value of charging and discharging between the battery and the capacitor to zero and start counting the cumulative duration of the restriction if it is determined based on the real-time current value that the capacitor is in a charging state when the battery heating stop information is received.

8. A battery heating method, characterized in that: A controller for use in a battery heating system; the battery heating system comprises the controller, a three-phase full-bridge inverter, a capacitor, a first switch, a second switch, and a motor; the DC side of the three-phase full-bridge inverter is connected to a battery, and the AC side of the three-phase full-bridge inverter is respectively connected to the three-phase windings of the motor; the capacitor is connected in parallel to the DC side of the three-phase full-bridge inverter; a first end of the first switch is connected to the positive electrode of the battery, and a second end of the first switch is connected to the first end of the second winding in the three-phase winding, wherein the three-phase winding comprises a first winding, a second winding, and a third winding, and the second end of the first winding, the second end of the second winding, and the second end of the third winding are connected in common; the first end of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter; The method comprises: When the first switch is closed and the second switch is open, the first bridge arm and the third bridge arm in the three-phase full-bridge inverter are controlled to charge and discharge the capacitor and the battery, so as to heat the battery.

9. An electronic device, characterized in that: include: memory and processor; The memory is connected to the processor and is used to store programs; The processor is configured to implement the battery heating method according to claim 8 by running the program in the memory.

10. A computer program product, characterized in that includes computer program instructions; When the computer program instructions are executed by a processor, the processor is caused to perform the battery heating method according to claim 8 .

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