Battery heating system, method, apparatus, and program product

Abstract

The application relates to the technical field of batteries, in particular to a battery heating system, method, device 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 a battery, and the alternating-current side of the three-phase full-bridge inverter is connected with three-phase windings 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 positive pole of the battery, and the second end of the first switch is connected with the first end of a second winding in the three-phase windings; the first end of the second switch is connected with the bridge arm midpoint of a second bridge arm in the three-phase full-bridge inverter, and the second end of the second switch is connected with the first end of the second winding; the controller is used for realizing cyclic and alternating charging and discharging of the battery, and heating the battery. The application can reduce the hardware modification cost and improve the safety of battery heating on the basis of guaranteeing efficient heating of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery heating system, method, device, and procedure. Background Technology

[0002] In recent years, battery-powered new energy vehicles have become increasingly common, while the environmental adaptability requirements for these vehicles have also increased. In low-temperature conditions, excessively low battery temperatures in new energy vehicles can lead to various problems such as charging difficulties, low discharge efficiency, and reduced cycle life. Therefore, battery heating in low-temperature environments is crucial for efficient battery operation. Existing technology provides a battery heating method that uses a motor and controller to achieve pulse heating by controlling the charging and discharging of the battery and capacitor. However, this method requires connecting a neutral point from the vehicle's load motor to the battery, necessitating significant structural modifications to the motor. This increases hardware modification costs, raises the risk of damage to both the motor and battery, and reduces battery heating efficiency. Summary of the Invention

[0003] Based on the defects and shortcomings of the prior art, this application proposes a battery heating system, method, device and program product that can reduce hardware modification costs and improve battery heating safety while ensuring efficient heating of the battery.

[0004] According to a first aspect of this 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 terminal of the first switch is connected to the positive terminal of the battery, and a second terminal of the first switch is connected to the first terminal of the second winding of the three-phase winding, wherein the three-phase winding includes a first winding, a second winding, and a third winding, and the second terminals of the first winding, the second winding, and the third winding are shared; a first terminal of the second switch is connected to the midpoint of the second bridge arm of the three-phase full-bridge inverter, and a second terminal of the second switch is connected to the first terminal of the second winding; the controller is configured to control the first and third bridge arms of the three-phase full-bridge inverter to charge and discharge the capacitor and the battery, thereby heating the battery, when the first switch is closed and the second switch is open.

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

[0006] The battery heating system provided according to the first aspect of this application further includes a first current sensor and a second current sensor; a 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 a second end of the first current sensor is connected to the first end of the first winding; a 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 a second end of the second current sensor is connected to the first end of the third winding; the controller is configured to, when the first switch is closed and the second switch is open, acquire a first current value detected by the first current sensor and acquire a second current value detected by the second current sensor, 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 this application, the controller is specifically configured to, when the first switch is closed and the second switch is open, 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, control the switching on and off of the switch in the first bridge arm based on the first duty cycle, and control the switching on and off of the switch in the third bridge arm based on the second duty cycle.

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

[0009] According to the battery heating system provided in the first aspect of this application, the controller is further configured to, when the first switch is closed and the second switch is open, if a battery heating stop information is received, acquire the real-time current value 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 duration of the current limitation between the battery and the capacitor reaches a duration threshold when the battery heating stop information is received, control the switching transistors 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 this 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 for charging and discharging between the battery and the capacitor to zero, and start counting the cumulative duration of the limit.

[0011] According to a second aspect of this application, a battery heating method is provided, 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 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; a first terminal of the first switch is connected to the positive terminal of the battery, and a second terminal of the first switch is connected to the first terminal 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 terminals of the first winding, the second winding, and the third winding are shared; a first terminal of the second switch is connected to the midpoint of the second bridge arm in 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 in 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 this 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 this application, a computer program product is provided, comprising computer program instructions; said computer program instructions, when executed by a processor, cause the processor to perform the battery heating method as described in the second aspect.

[0014] In this 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 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 terminal of the first switch is connected to the positive terminal of the battery, and the second terminal of the first switch is connected to the first terminal of the second winding in the three-phase winding. The three-phase winding includes a first winding, a second winding, and a third winding, and the second terminals of the first winding, the second winding, and the third winding are connected together. The first terminal of the second switch is connected to the midpoint of the second bridge arm in the three-phase full-bridge inverter, and the second terminal of the second switch is connected to the first terminal of the second winding. The controller is used to control the first and third bridge arms 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 scheme, the three-phase windings in the motor act as inductors, and these inductors, along with the capacitor, serve as energy storage elements to achieve charging and discharging between the capacitor and the battery. This achieves efficient heating of the battery based on its own impedance. Furthermore, compared to schemes that draw a neutral point from the motor, this application only uses a first and a second switch to switch the system's state, requiring minimal hardware modifications and reducing hardware upgrade costs. In summary, the solution provided by this application can reduce hardware upgrade costs and improve battery heating safety while ensuring efficient battery heating. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

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

[0017] Figure 2 This is a schematic diagram illustrating the principle of a battery heating system applied to battery heating, as provided in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram illustrating the principle of battery discharge based on a battery heating system, as provided in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram illustrating the principle of battery charging based on a battery heating system, as provided in an embodiment of this application.

[0020] Figure 5This is a schematic diagram illustrating the principle of a battery heating system applied to power supply, as provided in an embodiment of this application.

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

[0022] Figure 7 This is a schematic diagram illustrating the software control principle of battery heating, as provided in an embodiment of this application.

[0023] Figure 8 This is a schematic diagram of the control logic of a battery heating system applied to a vehicle, as provided in an embodiment of this application.

[0024] Figure 9 This is a schematic diagram illustrating a software control principle for preventing capacitor damage, provided in an embodiment of this application.

[0025] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0026] Figure label:

[0027] K1 - First switch; K2 - Second switch; K3 - Third switch; K4 - Fourth switch; C1 - Capacitor; R1 - Resistor; S1 - First switching transistor; S2 - Second switching transistor; S3 - Third switching transistor; S4 - Fourth switching transistor; S5 - Fifth switching transistor; S6 - Sixth switching transistor; L1 - First winding; L2 - Second winding; L3 - Third winding; A1 - First current sensor; A2 - Second current sensor. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Exemplary System

[0030] In view of the problems existing in the battery heating technology, this application provides a battery heating system.

[0031] In one embodiment, such as Figure 1 As shown, the battery heating system includes a controller (not labeled) Figure 1The system comprises 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 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. The first terminal of the first switch K1 is connected to the positive terminal of the battery, and the second terminal of the first switch K1 is connected to the first terminal of the second winding L2 in the three-phase windings. The three-phase windings include a first winding L1, a second winding L2, and a third winding L3. The second terminals of the first winding L1, the second winding L2, and the third winding L3 are connected together. The first terminal of the second switch K2 is connected to the midpoint of the second bridge arm in the three-phase full-bridge inverter 101, and the second terminal of the second switch is connected to the first terminal of the second winding. The controller is used to control the first and third bridge arms of the three-phase full-bridge inverter 101 to charge and discharge the capacitor C1 with the battery in order to heat the battery when the first switch K1 is closed and the second switch K2 is open.

[0032] In this embodiment, the three-phase full-bridge inverter 101 includes six switching transistors, designated as 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 the first bridge arm, the second switching transistor S2 and the fifth switching transistor S5 form the second bridge arm, and the third switching transistor S3 and the sixth switching transistor S6 form the 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 device or module suitable for inverters. On the DC side of the three-phase full-bridge inverter 101, a capacitor is connected in parallel. Optionally, this capacitor can be a film capacitor. Film capacitors have advantages such as high frequency and low loss, self-healing, long life, and wide temperature stability, and are particularly suitable for new energy and automotive electronics fields. It should be noted that the specific specifications of capacitor C1, such as its capacitance value, are determined in advance according to actual conditions and needs, and the scope of protection of this application is not limited by the specific specifications of capacitor C1.

[0033] 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, second winding L2, and third winding L3 correspond to the three phases respectively, for example, the first winding L1, second winding L2, and third winding L3 correspond to the U phase, V phase, and 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, that is, the first end of the second switch K2 is connected to the midpoint of the second bridge arm in 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 end of the second winding L2, and the second end of the third winding L3 are connected together to form a neutral point.

[0034] In this embodiment, Figure 1 The battery in this context refers to a battery that needs to be heated. A first switch K1 is added between the battery and the second winding L2, with the first end of the first switch K1 connected to the positive terminal of the battery and the second end of the first switch K1 connected to the first end of the second winding L2.

[0035] In this embodiment, to ensure the normal function of the battery outputting power to the motor, a third switch K3 is connected in series between the positive terminal of the battery and the DC side of the three-phase full-bridge inverter 101 as a main power switch. That is, the first end of the third switch K3 is connected to the positive terminal of the battery, and the second end of the third switch K3 is connected to the DC input terminal of the first switching transistor S1. A fourth switch K4 is also connected in series between the positive terminal of the battery and the DC side of the three-phase full-bridge inverter 101 as a pre-charge bypass switch, and a series resistor R1 is connected as a pre-charge resistor. That is, the first end of the fourth switch K4 is connected to the positive terminal of the battery, 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 terminal of the first switching transistor S1. When the three-phase full-bridge inverter 101 is used to output power to the motor normally (i.e., when the first switch K1 is open and the second switch K2 is closed), the third switch K3 acts as the main power switch to control the on / off state of the high-voltage DC bus main circuit; resistor R1 limits the initial charging current of the battery to capacitor C1 to avoid instantaneous large current surges that could damage the components; the fourth switch K4 acts as a pre-charge bypass switch, short-circuiting resistor R1 after pre-charging to eliminate resistance loss and establish a low-voltage-drop main power path. Specifically, when the battery is outputting power to the motor normally, during the pre-charging stage, the third switch K3 is open and the fourth switch K4 is closed, and the battery slowly charges capacitor C1 through resistor R1; after pre-charging is completed, when the voltage of capacitor C1 approaches the battery voltage, the third switch K3 opens and closes, R1 is bypassed, and the system switches to full-power operation.

[0036] 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 close or open by the controller mentioned above, or it can be controlled to close or open by other control modules or control logic according to actual conditions and needs.

[0037] In this embodiment, the first switch K1 and the second switch K2 serve as control switches for the AC heating control circuit, realizing... Figure 1 The electrical system shown switches between normal power output and battery AC heating functions. If battery heating is required, the first switch K1 is closed and the second switch K2 is open. Figure 2 The diagram shows the equivalent electrical connection when the first switch K1 is closed and the second switch K2 is open, enabling AC heating of the battery. The controller controls the first and third arms of the three-phase full-bridge inverter 101, causing capacitor C1 to alternately charge and discharge with the battery to heat the battery.

[0038] In this embodiment, capacitor C1 is first pre-charged using the third switch K3 and the fourth switch K4, so that the voltage across the battery is equal to the voltage across capacitor C1. After pre-charging, the first switch K1 is closed and the second switch K2 is opened. The controller then controls the switching transistors in the first and third bridge arms, such as... Figure 3 As shown, a boost chopper circuit is formed based on the controller, capacitor C1, first bridge arm, third bridge arm, and three-phase windings to control battery discharge (i.e., capacitor C1 charging). Specifically, current flows out of the battery, passes through the three-phase windings in motor 102, and then through the first and third bridge arms to charge capacitor C1. Figure 4 As shown, a buck chopper circuit is formed based on the controller, capacitor C1, first bridge arm, third bridge arm, and three-phase windings to control the discharge of capacitor C1 (i.e., battery charging). Specifically, current flows out of capacitor C1, passes through the first and third bridge arms, and then through the three-phase windings in motor 102 to charge the battery. Due to the internal resistance of the battery, when capacitor C1 and the battery alternately switch between charging and discharging, current alternately flows in and out of the battery. The internal resistance of the battery generates heat, thereby raising the battery temperature and achieving the purpose of battery heating.

[0039] In one embodiment, the controller is also configured to control the switching transistors in the three-phase full-bridge inverter 101 to supply AC power to the motor 102 when the first switch K1 is open and the second switch K2 is closed.

[0040] In this embodiment, if battery heating is not required or battery heating is complete, the first switch K1 is closed and the second switch K2 is opened. Figure 5As shown, by controlling the on / off state of the third switch K3 and the fourth switch K4, as well as the on / off state of each switch in the three-phase full-bridge inverter 101, the DC power output from the battery is converted into the AC power required by the motor 102, and the battery normally provides power to the motor 102.

[0041] In this embodiment, by controlling the closing and opening of the first switch K1 and the second switch K2, flexible switching between normal power output from the motor and AC heating from the battery is achieved. Before and after the switching, the capacitor C1, the three-phase full-bridge inverter 101, and the motor windings are reused, which minimizes the addition of redundant devices, improves the utilization rate of various hardware devices, and reduces the overall hardware cost. Moreover, the greater reuse of devices and the less hardware modification can reduce the risk of hardware damage and improve the safety and reliability of the overall system.

[0042] In one embodiment, the battery heating system further includes a first current sensor A1 and a second current sensor A2. The first end of the first current sensor A1 is connected to the midpoint of the first bridge arm in the three-phase full-bridge inverter 101, and the second end of the first current sensor A1 is connected to the first end of the first winding L1. The first end of the second current sensor A2 is connected to the midpoint of the third bridge arm in the three-phase full-bridge inverter 101, and the second end of the second current sensor A2 is connected to the first end of the third winding L3. A controller is configured to, when the first switch K1 is closed and the second switch K2 is open, acquire a first current value detected by the first current sensor A1 and a second current value detected by the second current sensor A2, and control the first and third bridge arms in the three-phase full-bridge inverter 101 based on the target current value, the first current value, and the second current value.

[0043] In this embodiment, in order to improve the control accuracy of the AC heating process, such as 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 be selected according to the actual situation and needs, such as a Hall sensor. The target current value is the target value of the charging and discharging current between the battery and the capacitor C1. This target current value is preset according to the actual situation and heating requirements. For example, the target current value corresponds to the instantaneous value of a sinusoidal current waveform, and the change of the target current value conforms to a sinusoidal waveform. The formula for the current waveform corresponding to the target current value is as follows:

[0044] I = Asin(2πft);

[0045] Where I represents the instantaneous target current value, A represents the maximum current amplitude of the sine wave, f represents the current frequency, t represents time, π represents pi, and sin represents the sine function.

[0046] In this embodiment, the first current value and the second current value are synchronized to the controller. Based on the target current value, the first current value and the second current value, the controller precisely controls the switching transistors in the first bridge arm and the third bridge arm, 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.

[0047] In one embodiment, 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 K1 is closed and the second switch K2 is open; control the switching on and off of the switch in the first bridge arm based on the first duty cycle; and control the switching on and off of the switch in the third bridge arm based on the second duty cycle.

[0048] In this embodiment, the controller employs a Proportional-Integral-Derivative (PID) algorithm and duty cycle adjustment to control the switching transistors in the first and third bridge arms. Specifically, after acquiring the actual first and second current values ​​flowing through the circuit, the controller calculates the current difference between the first and second current values ​​and the target current value, respectively. This current difference is used as the input to the PID algorithm, and the PID calculation is performed on the current difference to dynamically output the pulse width modulation (PWM) duty cycle corresponding to the first and third bridge arms, respectively, i.e., the first duty cycle corresponding to the first bridge arm and the second duty cycle corresponding to the third bridge arm. The on / off time of the switching transistor in the first bridge arm is dynamically controlled based on the first duty cycle, and the on / off time of the switching transistor in the third bridge arm is dynamically controlled based on the second duty cycle. By adjusting the first and second duty cycles, the effective value of the output voltage of the first and third bridge arms is changed, thereby adjusting the current value flowing through the first and third bridge arms. This makes the actual first and second current values ​​closer to the target current value required for heating, thereby improving the battery heating effect.

[0049] In one embodiment, the controller is also used to control the switching transistor in the second bridge arm to turn off.

[0050] In this embodiment, during the battery heating process, all the switching transistors in the second bridge arm are in the off state, such as... Figure 2As shown, the controller controls the on and off of the first switch S1 and the fourth switch S4 based on the first duty cycle, and controls the on and off of the third switch S3 and the sixth switch S6 based on the second duty cycle. At the same time, the second switch S2 and the fifth switch S5 are in the off state throughout the heating process to avoid forming redundant loops, improve the accuracy of current path control and battery heating efficiency; avoid forming a direct path between the second switch S2 and the fifth switch S5, which could lead to a short circuit on the DC bus and burn out the devices, thus improving system safety; reduce the adjustment complexity of the switches, avoid unnecessary switching actions, and extend the service life of the switches.

[0051] 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, as... Figure 7 As shown, the charging and discharging current between the battery and capacitor C1 is preset to 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 phase U, and the second current sensor A2 collects the real-time second current value of phase W. The controller uses a PID algorithm to calculate the current difference between phase U and phase W based on the target current value, the first current value, and the second current value. Based on the current difference, PID calculations are performed to output the first duty cycle required for phase U and the second duty cycle required for phase W. The controller keeps the switch in the second bridge arm corresponding to phase V off, adjusts the on / off state of the switch in the first bridge arm based on the first duty cycle, and adjusts the on / off state of the switch in the third bridge arm based on the second duty cycle, thereby achieving cyclic charging and discharging of the battery and thus achieving AC heating of the battery.

[0052] In one embodiment, when the first switch K1 is closed and the second switch K2 is open, if heating suddenly needs to be stopped during the charging process of capacitor C1 (i.e., battery discharge), and if the controller directly controls the switching transistors in the three-phase full-bridge inverter 101 to turn off, then because the battery is charging capacitor C1 at this time, and the current flowing through the three-phase windings of the motor 102, which acts as an inductor, cannot change abruptly, it can continue to charge capacitor C1 through the freewheeling diodes corresponding to the first switching transistor S1 in the first bridge arm and the third switching transistor S3 in the third bridge arm, respectively, resulting in a significant risk of overvoltage damage to capacitor C1.

[0053] In this embodiment, to avoid the risk of overvoltage damage to capacitor C1 caused by a sudden shutdown during charging, the controller is further configured to, when the first switch K1 is closed and the second switch K2 is open, if a battery heating stop information is received, obtain the real-time current value in the first bridge arm and the third bridge arm; if it is determined based on the real-time current value that capacitor C1 is in a discharging state, or if the cumulative duration of the current limit between the battery and capacitor C1 reaches a time threshold when the battery heating stop information is received, control the switching transistors in the first bridge arm and the third bridge arm to turn off.

[0054] In this embodiment, the battery heating stop information refers to information indicating the cessation of the battery heating process, such as system shutdown fault information or system shutdown commands. 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 capacitor C1 is in a discharging or charging state based on the real-time current values ​​in the first and third bridge arms. If capacitor C1 is in a discharging state (battery in a charging state), the voltage of capacitor C1 continuously decreases, eliminating the risk of overvoltage damage, and the switches in the first and third bridge arms can be turned off. If capacitor C1 is in a charging state (battery in a discharging state), the system compares the cumulative duration of the limit with a duration threshold to determine whether the current limit between the battery and capacitor C1 has reached a level sufficient to prevent overvoltage damage to capacitor C1. If the cumulative duration reaches the duration threshold, it indicates that the current limit between the battery and capacitor C1 has sufficiently limited the freewheeling charge of capacitor C1, and the switches in the first and third bridge arms can 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 scope of protection of this application is not limited by the specific value of the duration threshold.

[0055] In one embodiment, the controller is further configured to, when receiving battery heating stop information and determining that capacitor C1 is in a charging state based on real-time current value, limit the target current value for charging and discharging between the battery and capacitor C1 to zero and start counting the cumulative duration of the limit when the first switch K1 is closed and the second switch K2 is open.

[0056] In this embodiment, when the first switch K1 is closed and the second switch K2 is open, upon receiving a battery heating stop information, if it is determined based on the real-time current value that capacitor C1 is in a charging state, the target current value for charging and discharging between the battery and capacitor C1 is immediately set to zero. This aims to limit the actual current value in the first and third bridge arms, reducing it to zero. Since the current reduction process requires a certain time, the cumulative limitation period is immediately started upon receiving the battery heating stop information. If, during the limitation process, capacitor C1 stops charging, or the cumulative limitation period reaches a threshold, the switches in the first and third bridge arms are turned off, and the cumulative limitation period is reset to zero. By limiting the cumulative duration, other safety risks caused by excessive current limiting time are avoided, thus improving safety.

[0057] In one specific embodiment, the battery heating system is configured in the vehicle, wherein the battery is the vehicle's power battery, the motor 102 is the vehicle's load motor, and the three-phase full-bridge inverter 101 is a three-phase full-bridge inverter configured in the vehicle to normally provide power to the vehicle's load motor.

[0058] In this embodiment, as Figure 8 As shown, the control logic of the battery heating system applied to the vehicle is as follows:

[0059] Step 801: Put the vehicle in neutral to ensure that the motor 102 can rotate;

[0060] Step 802: Perform motor pre-positioning, that is, control the rotor of motor 102 to rotate so that two phases of 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, rotating the rotor of motor 102 to a position of 120° will make the U / W phase currents the same. After the pre-positioning is completed, the rotor of motor 102 will no longer rotate, thus maintaining that two phases of the three-phase current are the same.

[0061] Step 803: The controller switches to battery heating mode, and simultaneously controls the first switch K1 to close and the second switch K2 to open.

[0062] Optionally, the controller in the battery heating system is a vehicle motor control unit (MCU), which is mainly used to control the switching transistors 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 the vehicle control unit (VCU). The motor controller is pre-configured with various vehicle models such as torque model, speed model, and battery heating mode. When it is necessary to heat the vehicle's power battery, the motor controller can be switched to battery heating mode. Under this battery heating model, the preset programs related to battery heating can be called to realize the control logic required during the battery heating process.

[0063] Step 804: The controller controls the switching transistors in the first and third bridge arms to achieve boost chopper and battery discharge (i.e., capacitor charging). Based on the monitoring of the actual current values ​​(including the first and second current values) in the first and third bridge arms by the first current sensor A1 and the second current sensor A2, if the actual current value conforms to the sinusoidal current as the target current value, the actual current value during the battery discharge (i.e., capacitor charging) process is determined to be a positive current value.

[0064] Step 805: The controller controls the switching transistors in the first and third bridge arms to achieve buck chopper and battery charging (i.e. capacitor discharging). Based on the monitoring of the actual current values ​​in the first and third bridge arms by the first current sensor A1 and the second current sensor A2, if the actual current value conforms to the sinusoidal current as the target current value, the actual current value during the battery discharging (i.e. capacitor charging) process is determined to be a negative current value.

[0065] In the above process, steps 804 and 805 are executed alternately during the battery heating process, thereby enabling long-term monitoring and real-time control of the actual current value and improving the safety of the battery heating process.

[0066] In this embodiment, to prevent overvoltage damage to capacitor C1 caused by a sudden stop in heating during battery discharge (i.e., capacitor charging), such as... Figure 9 As shown, the controller implements the following control logic:

[0067] Step 901: The MCU receives the battery heating command sent by the vehicle;

[0068] Step 902: The MCU switches to battery heating mode and performs AC heating by cyclically charging and discharging the battery.

[0069] Step 903: Determine whether a battery heating stop message has been received. If yes, proceed to step 904; otherwise, proceed to step 902.

[0070] Optionally, the battery heating stop information includes a stop heating command sent by the VCU, as well as fault shutdown information generated by the MCU itself;

[0071] Step 904: Real-time detection of the actual current values ​​in the first and third bridge arms;

[0072] Step 905: Determine whether capacitor C1 is in a charging state (battery in a discharging state) based on the actual current value. If yes, proceed to step 906; otherwise, proceed to step 908.

[0073] Step 906: Limit the target current value for charging and discharging between the battery and capacitor C1 to zero, and count the cumulative duration of the limit;

[0074] When the cumulative duration limit is first calculated, the initial value of the cumulative duration limit is 0.

[0075] Step 907: Determine whether the cumulative time limit has reached the time threshold. If yes, proceed to step 908; otherwise, proceed to step 905.

[0076] Step 908: Control the switching transistors in the first and third bridge arms to turn off.

[0077] If the cumulative time limit is not zero when executing step 908, the cumulative time limit will be cleared to zero.

[0078] In this 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 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 terminal of the first switch is connected to the positive terminal of the battery, and the second terminal of the first switch is connected to the first terminal of the second winding in the three-phase winding. The three-phase winding includes a first winding, a second winding, and a third winding, and the second terminals of the first winding, the second winding, and the third winding are connected together. The first terminal of the second switch is connected to the midpoint of the second bridge arm in the three-phase full-bridge inverter, and the second terminal of the second switch is connected to the first terminal of the second winding. The controller is used to control the first and third bridge arms 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 scheme, the three-phase windings in the motor act as inductors, and these inductors, along with the capacitor, serve as energy storage elements to achieve charging and discharging between the capacitor and the battery. This achieves efficient heating of the battery based on its own impedance. Furthermore, compared to schemes that draw a neutral point from the motor, this application only uses a first and a second switch to switch the system's state, requiring minimal hardware modifications and reducing hardware upgrade costs. In summary, the solution provided by this application can reduce hardware upgrade costs and improve battery heating safety while ensuring efficient battery heating.

[0079] Furthermore, the solution provided in this application requires less hardware modification, mainly by altering the software control algorithm in the controller to achieve AC heating of the battery. Moreover, when the battery heating system needs to be stopped suddenly, the actual current direction is determined based on the real-time current value, avoiding capacitor overvoltage damage caused by sudden shutdown during capacitor charging (i.e., battery discharging). By limiting the target current value and statistically limiting the cumulative duration, the current is controlled before the switching transistor is turned off, ensuring timely system shutdown while improving device safety.

[0080] Exemplary methods

[0081] Accordingly, this 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 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 terminal of the first switch is connected to the positive terminal of the battery, and the second terminal of the first switch is connected to the first terminal of the second winding in the three-phase winding. The three-phase winding includes a first winding, a second winding, and a third winding, and the second terminals of the first winding, the second winding, and the third winding are connected together. The first terminal of the second switch is connected to the midpoint of the second bridge arm in the three-phase full-bridge inverter.

[0082] The battery heating method implemented in the controller 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 in order to heat the battery.

[0083] In one embodiment, the battery heating method implemented in the controller further includes: controlling the switching transistors in the three-phase full-bridge inverter to supply AC power to the motor when the first switch is open and the second switch is closed.

[0084] In one embodiment, the battery heating system further includes a first current sensor and a second current sensor; a 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 a second end of the first current sensor is connected to the first end of the first winding; a 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 a second end of the second current sensor is connected to the first end of the third winding.

[0085] The battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, acquiring a first current value detected by a first current sensor and acquiring a second current value detected by a second current sensor, and controlling the first and third bridge arms of the three-phase full-bridge inverter based on the target current value, the first current value and the second current value.

[0086] In one embodiment, the battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, performing 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; controlling the switching on and off of the switch in the first bridge arm based on the first duty cycle; and controlling the switching on and off of the switch in the third bridge arm based on the second duty cycle.

[0087] In one embodiment, the battery heating method implemented in the controller includes: controlling the switch in the second bridge arm to turn off.

[0088] In one embodiment, the battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, if a battery heating stop information is received, then the real-time current value in the first bridge arm and the third bridge arm is obtained; 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 reaches a duration threshold when the battery heating stop information is received, then the switching transistors in the first bridge arm and the third bridge arm are controlled to turn off.

[0089] In one embodiment, the battery heating method implemented in the controller includes: when the first switch is closed and the second switch is open, upon receiving battery heating stop information, if it is determined based on the real-time current value that the capacitor is in a charging state, then the target current value for charging and discharging between the battery and the capacitor is limited to zero, and the cumulative duration of the limitation is started to be counted.

[0090] The battery heating method provided in this embodiment belongs to the same concept as the battery heating system provided in the above embodiments of this application. It can be implemented in the controller of the battery heating system provided in any of the above embodiments of this application and has the corresponding beneficial effects of the technical solution for implementing the battery heating system. Technical details not described in detail in this embodiment can be found in the specific processing content of the battery heating method provided in the above embodiments of this application, and will not be repeated here.

[0091] Exemplary electronic devices

[0092] This application also provides an electronic device, such as... Figure 10 As shown, the electronic device includes a memory 1000 and a processor 1001.

[0093] The memory 1000 is connected to the processor 1001 and is used to store programs.

[0094] The processor 1001 is used to implement the battery heating method in the above embodiments by running the program stored in the memory 1000.

[0095] Specifically, the aforementioned electronic device may also include: a communication interface 1002, an input device 1003, an output device 1004, and a bus 1005.

[0096] The processor 1001, memory 1000, communication interface 1002, input device 1003, and output device 1004 are interconnected via a bus. Among them:

[0097] Bus 1005 may include a pathway for transmitting information between various components of a computer system.

[0098] The processor 1001 can be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present invention. It can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0099] Processor 1001 may include a main processor, as well as a baseband chip, modem, etc.

[0100] The memory 1000 stores a program that executes the technical solution of this invention, and may also store an operating system and other key business functions. Specifically, the program may include program code, which includes computer operation instructions. More specifically, the 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, etc.

[0101] Input device 1003 may include a device for receiving data and information input by the user, such as a keyboard, mouse, camera, scanner, light pen, voice input device, touch screen, pedometer or gravity sensor, etc.

[0102] Output device 1004 may include devices that allow information to be output to a user, such as a display screen, printer, speaker, etc.

[0103] The communication interface 1002 may include a device that uses any transceiver to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0104] The processor 1001 executes the program stored in the memory 1000 and calls other devices, which can be used to implement the various steps of the battery heating method provided in the above embodiments of this application.

[0105] Exemplary computer program products and storage media

[0106] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the battery heating method described in the embodiments of this application.

[0107] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can 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.

[0108] Furthermore, embodiments of this application may also be storage media storing a computer program, which is executed by a processor of the steps in the battery heating method described in the embodiments of this application.

[0109] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0110] 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. Similar or identical parts between embodiments can be referred to interchangeably. For apparatus embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0111] The steps in the methods of the various embodiments of this application can be adjusted, merged, or deleted in order according to actual needs, and the technical features described in each embodiment can be replaced or combined.

[0112] The modules and sub-modules in the devices and terminals provided in the various embodiments of this application can be merged, divided, and deleted according to actual needs.

[0113] It should be understood that the disclosed terminals, devices, and methods can be implemented in other ways, given the several embodiments provided in this application. For example, the terminal embodiments described above are merely illustrative. For instance, the division of modules or sub-modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple sub-modules or modules may be combined or integrated into another module, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0114] The modules or submodules described as separate components may or may not be physically separate. The components that constitute a module or submodule 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 can be selected to achieve the purpose of this embodiment's solution, depending on actual needs.

[0115] Furthermore, the functional modules or sub-modules in the various embodiments of this application can be integrated into one processing module, or each module or sub-module can exist physically separately, or two or more modules or sub-modules can be integrated into one module. The integrated modules or sub-modules described above can be implemented in hardware or in the form of software functional modules or sub-modules.

[0116] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can 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.

[0117] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software unit executed by a processor, or a combination of both. The software unit can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0118] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0119] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily 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 this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery heating system, characterized in that, Includes controller, three-phase full-bridge inverter, capacitor, first switch, second switch and 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 connected to the three-phase windings of the motor respectively. 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 terminal 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. The three-phase winding includes a first winding, a second winding, and a third winding. The second ends of the first winding, the second winding, and the third winding are connected together. The first end of the second switch is connected to the midpoint of the second bridge arm in 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 and third bridge arms of 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. The controller, capacitor, first bridge arm, third bridge arm and three-phase winding form a boost chopper circuit and a buck chopper circuit to control the battery discharge and charge. The controller is further configured to, when the first switch is closed and the second switch is open, if a battery heating stop information is received, acquire the real-time current value 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 duration of the current limitation between the battery and the capacitor reaches a duration threshold when the battery heating stop information is received, control the switching transistors in the first bridge arm and the third bridge arm to turn off.

2. The battery heating system according to claim 1, characterized in that, The controller is also used to control the switching transistors in the three-phase full-bridge inverter to supply AC power to the motor when the first switch is open and the second switch is closed.

3. The battery heating system according to claim 1, characterized in that, It 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 configured to acquire 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 configured to, when the first switch is closed and the second switch is open, 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, control the switching on and off of the switch in the first bridge arm based on the first duty cycle, and control the switching on and off of the switch 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 also used to control the switching transistor 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, 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 for charging and discharging between the battery and the capacitor to zero, and start counting the cumulative duration of the limit.

7. A battery heating method, characterized in that, A controller is used 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 the battery, and the AC side of the three-phase full-bridge inverter is 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 terminal of the first switch is connected to the positive terminal of the battery, and the second terminal of the first switch is connected to the first terminal of the second winding in the three-phase windings. The three-phase windings include a first winding, a second winding, and a third winding, and the second terminals of the first winding, the second winding, and the third winding are shared. The first terminal of the second switch is connected to the midpoint of the second bridge arm in the three-phase full-bridge inverter. The method includes: When the first switch is closed and the second switch is open, the first and third bridge arms of the three-phase full-bridge inverter are controlled to charge and discharge the capacitor and the battery to heat the battery. A boost chopper circuit and a buck chopper circuit are formed based on the controller, capacitor, first bridge arm, third bridge arm and three-phase winding to control the battery discharge and charge. When the first switch is closed and the second switch is open, if a battery heating stop information is received, the real-time current value in the first bridge arm and the third bridge arm is obtained. 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 reaches a duration threshold when the battery heating stop information is received, the switches in the first bridge arm and the third bridge arm are controlled to turn off.

8. 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 used to implement the battery heating method as described in claim 7 by running a program in the memory.

9. A computer program product, characterized in that, Includes computer program instructions; When the computer program instructions are executed by the processor, the processor causes the processor to perform the battery heating method as described in claim 7.

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