Charging and discharging device and control method thereof, vehicle, storage medium and electronic equipment

Abstract

The present application discloses a charging and discharging device and its control method, vehicle, storage medium and electronic equipment, which relate to the field of battery charging and discharging technology. The charging and discharging device includes: a multi-phase interleaved parallel Buck circuit; a switching circuit, the switching circuit is connected to the multi-phase Buck circuit and is suitable for connecting a power supply device and a power battery; a control circuit, the control circuit is respectively connected to the switching circuit and the multi-phase Buck circuit, and is used to control the switching circuit and the multi-phase Buck circuit so that the charging and discharging device operates in at least one of a step-down and current-boosting charging mode, a direct charging mode, a charging circulating heating mode and a non-charging circulating heating mode. The charging and discharging device is compatible with a variety of power supply devices of different voltage models to charge the power battery, and can also heat the motor in a low temperature environment when the multi-phase Buck circuit reuses the motor winding, thereby alleviating the problem of limited motor system capacity due to low temperature.

Description

Technical Field

[0001] The present application relates to the technical field of battery charging and discharging, and in particular to a charging and discharging device and a control method thereof, a vehicle, a storage medium, and an electronic device. Background Art

[0002] As the voltage levels of electric vehicle power batteries continue to increase, market demand for power supply devices is also increasing, and the output voltage range of power supply devices is also developing in a synchronous direction. However, most charging and discharging devices in related technologies can only realize one power supply device to charge the power battery, resulting in poor compatibility. Summary of the Invention

[0003] The purpose of this application is to propose a charging and discharging device and its control method, vehicle, storage medium and electronic equipment, so as to be compatible with power supply devices of multiple different voltage models to charge the power battery.

[0004] In the first aspect, an embodiment of the present application proposes a charging and discharging device, comprising: a multi-phase interleaved parallel Buck circuit; a switching circuit, the switching circuit being connected to the multi-phase Buck circuit and being suitable for connecting a power supply device and a power battery; a control circuit, the control circuit being respectively connected to the switching circuit and the multi-phase Buck circuit, and being used to control the switching circuit and the multi-phase Buck circuit so that the charging and discharging device operates in at least one of a buck-boost charging mode, a direct charging mode, a charging circulating current heating mode, and a non-charging circulating current heating mode.

[0005] In a second aspect, an embodiment of the present application proposes a vehicle, comprising: the charging and discharging device described in the embodiment of the first aspect; and a power battery, wherein the power battery is connected to a switching circuit in the charging and discharging device.

[0006] In the third aspect, an embodiment of the present application proposes a control method for a charging and discharging device, wherein the charging and discharging device includes a switching circuit and a multi-phase Buck circuit connected in parallel, the switching circuit is connected to the multi-phase Buck circuit, and is suitable for connecting a power supply device and a power battery: the method includes: controlling the switching circuit and the multi-phase Buck circuit so that the charging and discharging device operates in at least one of a step-down and current-boosting charging mode, a direct charging mode, a charging circulating current heating mode, and a non-charging circulating current heating mode.

[0007] In a fourth aspect, an embodiment of the present application proposes a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method described in the embodiment of the third aspect is implemented.

[0008] In the fifth aspect, an embodiment of the present application proposes an electronic device, comprising: at least one processor; a memory, wherein at least one program is stored in the memory, and when at least one of the programs is executed by at least one of the processors, the method described in the embodiment of the third aspect is implemented.

[0009] The charging and discharging device and its control method, vehicle, storage medium and electronic device of the embodiments of the present application, through the switching circuit, control circuit and multi-phase interleaved parallel Buck circuit, can enable the charging and discharging device to operate in at least one of the buck-boost charging mode, direct charging mode, charging circulating current heating mode, and non-charging circulating current heating mode, thereby being compatible with power supply devices of various voltage models. It can also achieve motor heating in a low-temperature environment when the multi-phase Buck circuit reuses the motor winding, thereby alleviating the problem of limited motor system capacity due to low temperature.

[0010] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a structural block diagram of a charging and discharging device according to an embodiment of the present application;

[0012] Figure 2 is a structural block diagram of a charging and discharging device according to another embodiment of the present application;

[0013] Figure 3 This is a schematic structural diagram of a charging and discharging device according to an embodiment of the present application;

[0014] Figure 4 is a structural schematic diagram of a charging and discharging device according to another embodiment of the present application;

[0015] Figure 5 1 is a schematic structural diagram of a charging and discharging device according to another embodiment of the present application;

[0016] Figure 6 This is a schematic diagram of the working mode of a three-phase Buck circuit according to an embodiment of the present application;

[0017] FIG7 (a) is a topological diagram of a buck-boost charging mode according to an example of the present application;

[0018] FIG7( b ) is a topological diagram of a charging loop heating mode according to an example of the present application;

[0019] Figure 8 This is a schematic diagram of the structure of a control circuit of an example of the present application;

[0020] FIG9( a ) is a topological diagram of a direct charging mode according to an example of the present application;

[0021] FIG9( b ) is a topological diagram of a non-charging circulating heating mode according to an example of the present application;

[0022] Figure 10 This is a topological diagram of a power battery supplying power to a low-voltage load in an example of the present application;

[0023] Figure 11 is a structural block diagram of a vehicle according to an embodiment of the present application;

[0024] Figure 12 is a structural block diagram of a vehicle according to another embodiment of the present application;

[0025] Figure 13 This is a structural block diagram of an electronic device according to an embodiment of the present application.

[0026] Description of reference numerals:

[0027] Vehicles 1000;

[0028] Charging and discharging device 100, power supply device 200, power battery 300, low-voltage load 400, electronic equipment 500;

[0029] Buck circuit 10, switch circuit 20, control circuit 30, processor 501, bus 502, memory 503, transceiver 504;

[0030] A first switch unit 21, a second switch unit 22, and a third switch unit 23;

[0031] A first switch K1, a second switch K2, a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, a seventh switch K7, a first capacitor C1, and a second capacitor C2. DETAILED DESCRIPTION

[0032] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0033] The following describes a charging and discharging device and a control method thereof, a vehicle, a storage medium, and an electronic device according to embodiments of the present application with reference to the accompanying drawings.

[0034] Figure 1 This is a structural block diagram of a charging and discharging device according to an embodiment of the present application.

[0035] like Figure 1 As shown, the charging and discharging device 100 includes: a multi-phase interleaved parallel Buck circuit 10, a switch circuit 20 and a control circuit 30.

[0036] See also Figure 1 The switching circuit 20 is connected to the multi-phase Buck circuit 10 and is suitable for connecting the power supply device 200 and the power battery 300. The control circuit 30 is connected to the switching circuit 20 and the multi-phase Buck circuit 10 respectively, and is used to control the switching circuit 20 and the multi-phase Buck circuit 10 to operate the charging and discharging device 100 in at least one of the buck-boost charging mode, the direct charging mode, the charging circulating current heating mode, and the non-charging circulating current heating mode.

[0037] The buck-boost charging mode and direct charging mode respectively refer to the buck-boost charging and DC charging of the power battery 300 by the power supply device 200 (such as a charging station or photovoltaic energy storage device). The Buck circuit may include a half-bridge circuit and a winding. The half-bridge circuit includes two switching transistors connected in series, with the midpoint of the half-bridge circuit (i.e., the connection point between the two switching transistors) connected to one end of the winding. The charging circulating current heating mode refers to the power supply device 200 simultaneously charging the power battery 300 while generating circulating current in the windings of the multi-phase Buck circuit. This can achieve motor heating when the multi-phase Buck circuit reuses the motor windings. The non-charging circulating current heating mode refers to the power battery 300 providing energy to generate circulating current in the windings of the multi-phase Buck circuit. This can achieve motor heating when the multi-phase Buck circuit reuses the motor windings.

[0038] The charging and discharging device 100 is compatible with power supply devices 200 of various voltage models, and can heat the motor when the motor windings are reused in a multi-phase Buck circuit, thereby alleviating the problem of limited motor system capacity due to low temperature.

[0039] In some embodiments of the present application, Figure 2 As shown, the switch circuit 20 is also suitable for connecting to a low-voltage load 400 , and the control circuit 30 is further used to control the switch circuit 20 and the multi-phase Buck circuit 10 to enable the power battery 300 to supply power to the low-voltage load 400 .

[0040] For example, the low-voltage load 400 may be a low-voltage electrical appliance of a vehicle, such as a lighting lamp, a signal lamp, an instrument, an in-vehicle multimedia, and the like.

[0041] In some examples, such as Figure 3 As shown, the switch circuit 20 includes a first switch unit 21 and a second switch unit 22 .

[0042] See also Figure 3 The first switch unit 21 is connected to the multi-phase Buck circuit 10 and is suitable for connecting to the power battery 300; the second switch unit 22 is connected to the multi-phase Buck circuit 10 and is suitable for connecting to the power supply device 200.

[0043] In this example, the control circuit 30 is connected to the first switch unit 21 and the second switch unit 22 respectively, and is used to control the on and off of the switches in the first switch unit 21 and the second switch unit 22 .

[0044] For example, Figure 4 As shown, the first switch unit 21 includes a first switch K1, a second switch K2, and a third switch K3. The first end of the first switch K1 and the first end of the second switch K2 are adapted to be connected to the first electrode (e.g., the positive electrode) of the power battery 300. The second end of the first switch K1 is connected to the first end of the multi-phase Buck circuit 10, the second end of the second switch K2 is connected to the second end of the multi-phase Buck circuit 10, the first end of the third switch K3 is adapted to be connected to the second electrode (e.g., the negative electrode) of the power battery 300, and the second end of the third switch K3 is connected to the third end of the multi-phase Buck circuit 10. The control circuit 30 is connected to the control ends of the first switch K1, the second switch K2, and the third switch K3, respectively, to control the on and off of the first switch K1, the second switch K2, and the third switch K3.

[0045] Optionally, to save costs, the first switch unit 21 may not include the third switch K3. To prevent the charge and discharge device 100 from being unable to operate after a switch fails, redundant switches may be provided corresponding to the switches K1, K2, and K3 as backup.

[0046] For example, see Figure 4 The second switch unit 22 includes a fourth switch K4 and a fifth switch K5. The first end of the fourth switch K4 is adapted to be connected to the second terminal of the power supply device 200, and the second end of the fourth switch K4 is connected to the third terminal of the multi-phase Buck circuit 10. The first end of the fifth switch K5 is adapted to be connected to the first terminal of the power supply device 200, and the second end of the fifth switch K5 is connected to the second terminal of the multi-phase Buck circuit 10. The control circuit 30 is connected to the control ends of the fourth switch K4 and the fifth switch K5, respectively, to control the on and off of the fourth switch K4 and the fifth switch K5.

[0047] Optionally, to save costs, the second switch unit 22 may not include the fourth switch K4. To prevent the charge and discharge device 100 from being unable to operate after a switch fails, redundant switches may be provided corresponding to the switches K4 and K5 as backup.

[0048] In some examples, such as Figure 3 As shown, the switch circuit 20 further includes: a third switch unit 23 .

[0049] See also Figure 3 The third switch unit 23 is connected to the multi-phase Buck circuit 10 and is suitable for connecting to a low-voltage load 400 .

[0050] In this example, the control circuit 30 is also connected to the third switch unit 23 and is used to control the on and off of the switch in the third switch unit 23 .

[0051] For example, see Figure 4 The third switch unit 23 includes a sixth switch K6 and a seventh switch K7. The first end of the sixth switch K6 is adapted to be connected to the first power supply terminal of the low-voltage load 400, and the second end of the sixth switch K6 is connected to the first end of the multi-phase Buck circuit 10. The first end of the seventh switch K7 is adapted to be connected to the second power supply terminal of the low-voltage load 400, and the second end of the seventh switch K7 is connected to the third end of the multi-phase Buck circuit 10. The control circuit 30 is connected to the control ends of the sixth switch K6 and the seventh switch K7, respectively, to control the on and off of the sixth switch K6 and the seventh switch K7.

[0052] Optionally, to save costs, the third switch unit 23 may not include the seventh switch K7. To prevent the charge and discharge device 100 from being unable to operate after a switch fails, redundant switches may be provided corresponding to switches K6 and K7 as backup.

[0053] In some examples of the present application, a multi-phase Buck circuit 10 includes multiple bridge arms and multiple inductors. The multiple bridge arms correspond one-to-one to the multiple inductors. The first ends of the multiple bridge arms are interconnected, the second ends of the multiple bridge arms are interconnected, the midpoint of each bridge arm is connected to the first end of the corresponding inductor, and the second ends of the inductors are interconnected. Based on this, the multi-phase Buck circuit 10 reuses at least two bridge arms of the vehicle motor drive circuit and the inductance of at least two motor windings corresponding to the at least two bridge arms.

[0054] For example, see Figure 4 The three-phase interleaved parallel Buck circuit 10 reuses the three-phase bridge arm of the motor drive circuit and its corresponding three-phase motor winding inductance. The three-phase bridge arm consists of switches S1-S6 and diodes D1-D6, and the three inductors are L1, L2, and L3.

[0055] In some embodiments of the present application, Figure 5 As shown, the charge and discharge device 100 further includes: a first capacitor C1.

[0056] See also Figure 5 The first capacitor C1 is connected between the second end of the second switch K2 and the second end of the third switch K3.

[0057] By providing the first capacitor C1 , pre-charging of the power battery 300 during the charging and discharging process can be achieved, thereby improving the charging and discharging stability of the power battery 300 and reducing ripples.

[0058] In some embodiments of the present application, Figure 5 As shown, the charge and discharge device 100 further includes: a second capacitor C2.

[0059] See also Figure 5 The second capacitor C2 is connected between the second end of the fourth switch K4 and the second end of the fifth switch K5.

[0060] By providing the second capacitor C2 , pre-charging of the power supply device 200 can be achieved during the charging process, thereby improving the stability of the power supply of the power supply device 200 and reducing ripple.

[0061] In some examples, when the control circuit 30 controls the switching circuit and the multi-phase Buck circuit so that the charging and discharging device 100 operates in the buck-boost charging mode, it is specifically used to: control the switching circuit 20 so that the power supply device 200 is connected to the power battery 300 through the multi-phase Buck circuit 10; and control the multi-phase Buck circuit 10 using a voltage-current dual closed-loop structure that controls the input voltage so that the power supply device 200 charges the power battery 300 with a constant current.

[0062] In some examples, the control circuit 30 controls the switching circuit 20 and the multi-phase Buck circuit 10 so that the charging and discharging device 100 operates in the buck-boost charging mode. In addition, the control circuit 30 is used to: after the power battery 300 is charged with a constant current, when the voltage of the power battery 300 reaches the constant voltage charging voltage, the multi-phase Buck circuit 10 is controlled by a voltage-current dual closed-loop structure that controls the output voltage, so that the power supply device 200 charges the power battery 300 with a constant voltage.

[0063] In some examples, when the control circuit 30 controls the switching circuit 20 and the multi-phase Buck circuit 10 so that the charging and discharging device 100 operates in the charging loop heating mode, it is specifically used to: control the switching circuit 20 so that the power supply device 200 is connected to the power battery 300 through the multi-phase Buck circuit 10; and use at least two control methods to control the multi-phase Buck circuit 10 so that the vector sum of the current flowing through the multi-phase Buck circuit 10 is the charging current.

[0064] In some examples, when the control circuit 30 controls the switch circuit 20 and the multi-phase Buck circuit 10 to enable the charging and discharging device 100 to operate in the direct charging mode, it is specifically used to: control the switch circuit 20 to directly connect the power supply device 200 to the power battery 300.

[0065] In some examples, the multi-phase Buck circuit 10 reuses at least two-phase bridge arms and at least two-phase motor windings of the vehicle motor drive circuit; when the control circuit 30 controls the switching circuit 20 and the multi-phase Buck circuit 10 so that the charging and discharging device 100 operates in the non-charging circulating heating mode, it is specifically used to: control the switching circuit 20 so that the bridge arms in the multi-phase Buck circuit 10 are connected to the power battery 300; and use at least two control methods to control the multi-phase Buck circuit 10 so that the vector sum of the current flowing through the multi-phase Buck circuit 10 is 0.

[0066] The following combination Figure 5 The illustrated embodiment describes the operation of the charge and discharge device 100 of the present application.

[0067] Figure 6 Shown Figure 5 The operating modes of the three-phase interleaved parallel Buck circuit 10 are shown in Figure 1. When the duty cycle varies, the three-phase interleaved parallel Buck circuit 10 will have different operating modes. Taking the duty cycle of (1 / 3, 2 / 3) as an example, the operating modes of the three-phase interleaved parallel Buck circuit 10 are analyzed.

[0068] Working mode 1: Switches S1 and S5 are turned on, inductors L1 and L3 store energy, and the inductor current i L1 、i L3 In the rising stage. The switch tube S3 is turned off, the inductor L2 releases energy through the freewheeling diode D4, and the inductor current i L2 In a declining phase.

[0069] Working mode 2: switch tube S1 is turned on, inductor L1 stores energy, inductor current i L1 In the rising stage. Switch tubes S3 and S5 are turned off, inductors L2 and L3 release energy through freewheeling diodes D4 and D6, and the inductor current i L2 、i L3 In a declining phase.

[0070] Working mode 3: Switches S1 and S3 are turned on, inductors L1 and L2 store energy, and the inductor current i L1 、i L2 In the rising stage. The switch tube S5 is turned off, the inductor L3 releases energy through the freewheeling diode D6, and the inductor current i L3 In a declining phase.

[0071] Working mode 4: switch tube S3 is turned on, inductor L2 stores energy, and inductor current i L2 In the rising stage. Switch tubes S1 and S5 are turned off, inductors L1 and L3 release energy through freewheeling diodes D2 and D6, and the inductor current i L1 、i L3 In a declining phase.

[0072] Working mode 5: Switches S3 and S5 are turned on, inductors L2 and L3 store energy, and the inductor current i L2 、i L3 In the rising stage. The switch tube S1 is turned off, the inductor L1 releases energy through the freewheeling diode D2, and the inductor current i L1 In a declining phase.

[0073] Working mode 6: switch tube S5 is turned on, inductor L3 stores energy, and inductor current i L3 In the rising stage. Switch tubes S1 and S3 are turned off, inductors L1 and L2 release energy through freewheeling diodes D2 and D4, and the inductor current i L1 、i L2 In a declining phase.

[0074] Figure 7(a) is a topological diagram of an example buck-boost charging mode of the present application, and Figure 7(b) is a topological diagram of an example charging loop heating mode of the present application. In both buck-boost charging mode and charging loop heating mode, the control circuit 30 controls switches K1, K3, K4, and K5 to close and switches K2, K6, and K7 to open. By controlling the on / off states and on / off durations of the switches in the three-phase Buck circuit 10, the voltage output by the power supply device 200 is reduced and the current is increased to charge the power battery 300. Controlling the on / off duration of the switches controls the duty cycle. The difference between the two modes is that in buck-boost charging mode, the three-phase Buck circuit 10 uses the same control method to evenly distribute the charging current. In charging loop heating mode, the three-phase Buck circuit 10 is independently controlled, using a three-phase unbalanced method to generate circulating current within the motor windings for auxiliary heating of the motor system. The three-phase current values ​​are both positive and negative, and the vector sum of the three-phase currents is the charging current, which can increase the system's heating power.

[0075] For buck-boost charging mode, see Figure 5 , in the conduction phase of the three switches S1, S3, and S5 of the upper bridge of the three-phase interleaved parallel Buck circuit 10, the voltage across the inductors L1, L2, and L3 is:

[0076]

[0077] During the turn-off phase of the three upper bridge switches S1, S3, and S5, the voltage across the inductors L1, L2, and L3 is:

[0078]

[0079] Assume that the input voltage V of the three-phase interleaved parallel Buck circuit 10 is in (t) (i.e., the voltage on the power supply device 200 side) and the output voltage Vo (t) (voltage at the power battery 300 side) is continuous and changes very little within a switching cycle. The average value of the voltage across the inductors L1, L2, and L3 within a switching cycle is used to represent the magnitude of the two. The average value of the voltage across the inductors L1, L2, and L3 within a switching cycle is:

[0080]

[0081] Wherein, d1(t), d2(t), and d3(t) respectively represent the duty cycle of the three-phase Buck circuit 10.

[0082] Figure 8 The structure of the control circuit 30 in the buck-boost charging mode is shown. In the buck-boost charging mode, the charging process of the battery includes a constant current charging stage and / or a constant voltage charging stage. In order to ensure the safety and stability of the charging process, the control circuit 30 uses a voltage-current dual closed-loop structure in each charging stage to control the voltage to realize the full-process charging of the power battery 300. Among them, the voltage-current dual closed-loop structure includes a voltage outer loop and three independent current inner loops, that is, the outer loop is a voltage loop, and the inner loop is composed of three independent current loops with the same structure connected in parallel, so as to realize current sharing control between each parallel Buck circuit 10.

[0083] In order to improve the accuracy and speed of current sharing control, this application compensates the current of each phase on the basis of the above double closed loop. Specifically: according to the imbalance of each phase current, the required current is compensated to reach a new steady-state point, and the current value of each phase after compensation is for:

[0084]

[0085] According to the equivalent circuit diagram of the three-phase interleaved parallel Buck circuit converter, the compensation current of each phase can be derived:

[0086]

[0087] in, 、 、 They represent the three-phase compensation current respectively, R1, R2, and R3 represent the parasitic resistance of the three-phase Buck circuit respectively (pre-set and can also be obtained by calculation), Vin represents the input voltage of the charging and discharging device (that is, the voltage on the power supply device 200 side), i1, i2, and i3 represent the current flowing through the inductor in the three-phase Buck circuit 10 respectively, which can be collected by the current sensor.

[0088] See also Figure 8 In the constant current charging stage, the voltage and current double closed loop structure is used to control the input voltage to achieve charging. After charging starts, the control circuit 30 obtains the input voltage Vin (i.e., the actual voltage on the power supply device 200 side) is used as the feedback value of the voltage loop, and the charging voltage setting value on the power supply device 200 side is V ref_in , the output of the voltage loop is used as the current setting value of the current loop; when the voltage of the power battery 300 does not reach the constant voltage charging voltage, the control stabilizes the output current at the constant current charging current. When the voltage of the power battery 300 reaches the constant voltage charging voltage, it switches to dual closed-loop control to control the output voltage.

[0089] In the constant voltage charging stage, the voltage and current double closed loop structure is used to control the output voltage to achieve charging. The control circuit 30 obtains the output voltage V out (i.e. the actual voltage on the power battery 300 side) is used as the feedback value of the voltage loop, and the charging voltage setting value on the power battery 300 side is V ref_out The output of the voltage loop serves as the current setting value for the current loop until charging is complete. It should be noted that during this phase, if the voltage of the power battery 300 falls below the constant voltage charging voltage, the system switches to the constant current charging phase, i.e., switches to a dual closed-loop control scheme that controls the input voltage. The current gradually increases to the constant current charging current based on the current value.

[0090] For example, in the dual closed-loop control structure used in the constant current charging stage and the constant voltage charging stage, both the voltage loop and the current loop can adopt the PI (Proportion Integration) control method; the output of the dual closed-loop control structure is a duty cycle, and when controlling each Buck circuit 10, a PWM (Pulse Width Modulation) wave form can be adopted.

[0091] Figure 9(a) is a topological diagram of an example direct charging mode of the present application. Referring to Figure 9(a), in direct charging mode, the control circuit 30 controls switches K2, K3, K4, and K5 to close, and switches K1, K6, and K7 to open, allowing the power supply device 200 to directly charge the power battery 300 with DC power.

[0092] Figure 9(b) is a topological diagram of an example non-charging circulating current heating mode in this application. Referring to Figure 9(b), in this non-charging circulating current heating mode, the three-phase Buck circuit 10 is independently controlled, the three-phase currents are both positive and negative, and the vector sum of the three-phase currents is zero. It should be noted that if the three-phase Buck circuit 10 reuses the motor drive circuit, the non-charging circulating current heating mode can also be referred to as the motor locked-rotor heating mode.

[0093] It should be noted that the arrows in FIG7( a ), FIG7 ( b ) and FIG9 ( b ) indicate the circuit flow direction.

[0094] Figure 10 This is a topological diagram of an example power battery supplying power to a low-voltage load in this application.

[0095] If a fault occurs in a vehicle's DC-DC (Direct Current Direct Current) module, the vehicle may become stranded and unable to power the vehicle's low-voltage loads. In this case, the control circuit 30 closes switches K2, K3, K6, and K7, and opens switches K1, K4, and K5. The power battery 300 then powers the vehicle's low-voltage loads 400 via the three-phase Buck circuit 10. This ensures the availability of critical low-voltage loads and enhances the user experience in the event of a vehicle breakdown.

[0096] In summary, the charge-discharge device of the embodiment of the present application can achieve the following beneficial effects:

[0097] 1) Reusing the vehicle's motor drive circuit to construct a buck-boost charging circuit eliminates the need for additional components, avoiding the cost and size increase associated with adding a buck DC-DC module for buck-boost charging of the power battery. Furthermore, the addition of multiple switches enables the circuit topology to implement buck-boost charging, direct charging, loop heating, and motor stall heating modes, improving charging compatibility between the vehicle and power supplies of different voltage models. Furthermore, the system can heat the motor in low-temperature environments, alleviating temperature-related limitations on the motor system's capabilities. In the event of a DC-DC module failure, the power battery can also provide energy for the vehicle's low-voltage loads.

[0098] 2) By using a dual closed-loop structure for control throughout the entire charging process (including the constant current charging stage and the constant voltage charging stage), and controlling the input voltage during the constant current charging stage, the stability of the charging process is improved, avoiding problems such as voltage jumps caused by multiple switching between completely different control methods;

[0099] 3) Based on the double closed-loop structure, the current of each phase is compensated to achieve rapid and accurate current sharing control.

[0100] Figure 11 It is a structural block diagram of a vehicle according to an embodiment of the present application.

[0101] like Figure 11 As shown, the vehicle 1000 includes a power battery 300 and the charge-discharge device 100 of the above embodiment. The power battery 300 is connected to the switch circuit 20 in the charge-discharge device 100.

[0102] In some embodiments of the present application, Figure 12 As shown, the vehicle 1000 further includes a low-voltage load 400 , which is connected to the switch circuit 20 .

[0103] The present application also proposes a control method for a charging and discharging device, which is used to control the charging and discharging device. The charging and discharging device includes a switching circuit and a multi-phase Buck circuit connected in parallel. The switching circuit is connected to the multi-phase Buck circuit and is suitable for connecting a power supply device and a power battery.

[0104] In an embodiment of the present application, a method for controlling a charge and discharge device includes:

[0105] The switch circuit and the multi-phase Buck circuit are controlled to make the charging and discharging device operate in at least one of a buck-boost charging mode, a direct charging mode, a charging circulating heating mode, and a non-charging circulating heating mode.

[0106] In the first embodiment of the present application, the switching circuit and the multi-phase Buck circuit are controlled so that the charging and discharging device operates in a buck-boost charging mode, including: controlling the switching circuit so that the power supply device is connected to the power battery through the multi-phase Buck circuit; and controlling the multi-phase Buck circuit using a voltage-current dual closed-loop structure that controls the input voltage so that the power supply device charges the power battery with a constant current.

[0107] In one embodiment, controlling the switching circuit and the multi-phase Buck circuit so that the charging and discharging device operates in a buck-boost charging mode also includes: after the power battery is charged with a constant current, when the voltage of the power battery reaches a constant voltage charging voltage, a voltage-current dual closed-loop structure that controls the output voltage is used to control the multi-phase Buck circuit so that the power supply device charges the power battery with a constant voltage.

[0108] Exemplarily, the voltage-current dual closed-loop structure includes a voltage outer loop and multiple independent current inner loops, wherein the multiple current inner loops correspond one-to-one to the multi-phase Buck circuit; wherein, when the voltage-current dual closed-loop structure is used to control the multi-phase Buck circuit, compensation is also performed on each phase current in each current inner loop.

[0109] When the number of Buck circuits is 3, the three-phase compensation current can be obtained by the following formula:

[0110]

[0111] in, 、 、 They represent the three-phase compensation current, R1, R2, and R3 represent the parasitic resistance of the three-phase Buck circuit, Vin represents the input voltage of the charging and discharging device, and i1, i2, and i3 represent the current flowing through the three-phase Buck circuit.

[0112] In a second embodiment of the present application, the switching circuit and the multi-phase Buck circuit are controlled so that the charging and discharging device operates in a charging circulation heating mode, including: controlling the switching circuit so that the power supply device is connected to the power battery through the multi-phase Buck circuit; and using at least two control methods to control the multi-phase Buck circuit so that the vector sum of the currents flowing through the multi-phase Buck circuit is the charging current.

[0113] For example, a Buck circuit includes a bridge arm and an inductor. The two control methods refer to different control methods for the bridge arms in a two-phase Buck circuit, including different positions of the controlled switching tubes (such as one controlling the upper bridge arm and the other controlling the lower bridge arm), different switching timings, and different duty cycles.

[0114] In a third embodiment of the present application, the switching circuit and the multi-phase Buck circuit are controlled so that the charging and discharging device operates in a direct charging mode, including: controlling the switching circuit so that the power supply device is directly connected to the power battery.

[0115] In a fourth embodiment of the present application, a multi-phase Buck circuit reuses at least two-phase bridge arms and at least two-phase motor windings of a vehicle motor drive circuit; controls the switching circuit and the multi-phase Buck circuit so that the charging and discharging device operates in a non-charging circulating heating mode, including: controlling the switching circuit so that the bridge arms in the multi-phase Buck circuit are connected to the power battery; and using at least two control methods to control the multi-phase Buck circuit so that the current vector sum flowing through the multi-phase Buck circuit is 0.

[0116] It should be noted that for other specific implementations of the control method of the charge and discharge device of the embodiment of the present application, reference can be made to the specific implementations of the charge and discharge device of the above embodiment.

[0117] Based on the control method of the charging and discharging device in the above embodiment, the present application proposes a computer-readable storage medium.

[0118] In an embodiment of the present application, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, the control method of the charging and discharging device of the above embodiment is implemented.

[0119] Figure 13 It is a structural block diagram of an electronic device according to an embodiment of the present application.

[0120] like Figure 13 As shown, electronic device 500 includes: memory 503 and at least one processor 501. Processor 501 and memory 503 are connected, for example, via bus 502. Optionally, electronic device 500 may further include a transceiver 504. It should be noted that in actual applications, the number of transceivers 504 is not limited to one, and the structure of electronic device 500 does not constitute a limitation on the embodiments of this application.

[0121] Processor 501 can be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 501 can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0122] Bus 502 may include a path for transmitting information between the above components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. Bus 502 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 13 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0123] The memory 503 is used to store one or more programs corresponding to the control method of the charge and discharge device of the above embodiment of the present application, and the program is controlled and executed by the processor 501. The processor 501 is used to execute the program stored in the memory 503 to implement the content shown in the above method embodiment.

[0124] Figure 13 The electronic device 500 shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0125] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having logic gate circuits for implementing logic functions on data signals, an application-specific integrated circuit having suitable combinational logic gate circuits, a programmable gate array (PGA), a field-programmable gate array (FPGA), etc.

[0126] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0127] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0128] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0129] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0130] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0131] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A charging and discharging device, characterized in that: include: Multi-phase interleaved parallel Buck circuit; A switching circuit, the switching circuit being connected to the multi-phase Buck circuit and being adapted to connect a power supply device and a power battery; a control circuit, the control circuit being connected to the switch circuit and the multi-phase Buck circuit respectively, and being used to control the switch circuit and the multi-phase Buck circuit so as to make the charging and discharging device operate in at least one of a buck-boost charging mode, a direct charging mode, a charging circulating current heating mode, and a non-charging circulating current heating mode; When the control circuit controls the switch circuit and the multi-phase Buck circuit to make the charging and discharging device operate in the buck-current-boost charging mode, the control circuit is specifically used to: The switching circuit is controlled so that the power supply device is connected to the power battery through the multi-phase Buck circuit; a voltage-current dual closed-loop structure that controls the input voltage is used to control the multi-phase Buck circuit so that the power supply device performs constant-current charging on the power battery; after the power battery is charged with constant current, when the voltage of the power battery reaches the constant-voltage charging voltage, the voltage-current dual closed-loop structure that controls the output voltage is used to control the multi-phase Buck circuit so that the power supply device performs constant-voltage charging on the power battery.

2. The charge and discharge device according to claim 1, wherein: The switching circuit comprises: a first switch unit, the first switch unit being connected to the multi-phase Buck circuit and being adapted to be connected to the power battery; a second switch unit, connected to the multi-phase Buck circuit and adapted to be connected to the power supply device; The control circuit is connected to the first switch unit and the second switch unit respectively, and is used to control the on and off of the switches in the first switch unit and the second switch unit.

3. The charge and discharge device according to claim 2, characterized in that: The switching circuit further includes: a third switch unit, the third switch unit being connected to the multi-phase Buck circuit and being suitable for connecting a low-voltage load; The control circuit is further connected to the third switch unit, and is used to control the on and off of the switch in the third switch unit, so that the power battery can supply power to the low-voltage load.

4. The charge and discharge device according to claim 2, wherein: The first switch unit includes a first switch, a second switch, and a third switch. The first end of the first switch and the first end of the second switch are adapted to be connected to the first terminal of the power battery. The second end of the first switch is connected to the first terminal of the multi-phase Buck circuit. The second end of the second switch is connected to the second terminal of the multi-phase Buck circuit. The first end of the third switch is adapted to be connected to the second terminal of the power battery. The second end of the third switch is connected to the third terminal of the multi-phase Buck circuit. The control circuit is connected to the control ends of the first switch, the second switch and the third switch respectively, and is used to control the on and off of the first switch, the second switch and the third switch.

5. The charge and discharge device according to claim 2, wherein: The second switch unit includes a fourth switch and a fifth switch, wherein a first end of the fourth switch is adapted to be connected to the second pole of the power supply device, and a second end of the fourth switch is connected to the third end of the multi-phase Buck circuit; a first end of the fifth switch is adapted to be connected to the first pole of the power supply device, and a second end of the fifth switch is connected to the second end of the multi-phase Buck circuit; The control circuit is connected to the control ends of the fourth switch and the fifth switch respectively, and is used to control the on and off of the fourth switch and the fifth switch.

6. The charge and discharge device according to claim 3, characterized in that: The third switch unit includes a sixth switch and a seventh switch, wherein a first end of the sixth switch is adapted to be connected to a first power supply end of the low-voltage load, and a second end of the sixth switch is connected to a first end of the multi-phase Buck circuit; a first end of the seventh switch is adapted to be connected to a second power supply end of the low-voltage load, and a second end of the seventh switch is connected to a third end of the multi-phase Buck circuit; The control circuit is connected to the control ends of the sixth switch and the seventh switch respectively, and is used to control the on and off of the sixth switch and the seventh switch.

7. The charge-discharge device according to any one of claims 1 to 6, characterized in that: The multi-phase Buck circuit multiplexes at least two-phase bridge arms of the vehicle motor drive circuit and at least two-phase motor windings corresponding to the at least two-phase bridge arms.

8. The charge and discharge device according to claim 4, characterized in that: The charging and discharging device further includes: A first capacitor is connected between the second end of the second switch and the second end of the third switch.

9. The charge and discharge device according to claim 5, characterized in that: The charging and discharging device further includes: A second capacitor is connected between the second end of the fourth switch and the second end of the fifth switch.

10. The charge and discharge device according to claim 1, wherein: When the control circuit controls the switch circuit and the multi-phase Buck circuit to make the charging and discharging device operate in the charging circulating current heating mode, the control circuit is specifically used to: Controlling the switch circuit so that the power supply device is connected to the power battery through the multi-phase Buck circuit; At least two control modes are used to control the multi-phase Buck circuits, so that the vector sum of the currents flowing through the multi-phase Buck circuits is the charging current.

11. The charge and discharge device according to claim 1, wherein: When the control circuit controls the switch circuit and the multi-phase Buck circuit to make the charging and discharging device operate in the direct charging mode, the control circuit is specifically used to: The switch circuit is controlled to connect the power supply device directly to the power battery.

12. The charge and discharge device according to claim 1, wherein: The multi-phase Buck circuit reuses at least two-phase bridge arms and at least two-phase motor windings of the vehicle motor drive circuit; when the control circuit controls the switch circuit and the multi-phase Buck circuit to make the charging and discharging device operate in the non-charging circulating current heating mode, it is specifically used to: Controlling the switch circuit so that the bridge arms in the multi-phase Buck circuit are connected to the power battery; At least two control modes are used to control the multi-phase Buck circuits so that the vector sum of the currents flowing through the multi-phase Buck circuits is zero.

13. A vehicle, characterized in that: include: The charging and discharging device according to any one of claims 1 to 12; as well as A power battery is connected to the switch circuit in the charging and discharging device.

14. The vehicle according to claim 13, characterized in that The vehicle further comprises: A low-voltage load is connected to the switch circuit.

15. A method for controlling a charge and discharge device, characterized in that: The charging and discharging device includes a switching circuit and a multi-phase interleaved parallel Buck circuit, the switching circuit is connected to the multi-phase Buck circuit and is suitable for connecting a power supply device and a power battery. The method includes: Controlling the switch circuit and the multi-phase Buck circuit to enable the charging and discharging device to operate in at least one of a buck-boost charging mode, a direct charging mode, a charging circulating current heating mode, and a non-charging circulating current heating mode; Controlling the switch circuit and the multi-phase Buck circuit so that the charging and discharging device operates in a buck-current-boost charging mode includes: The switching circuit is controlled so that the power supply device is connected to the power battery through the multi-phase Buck circuit; a voltage-current dual closed-loop structure that controls the input voltage is used to control the multi-phase Buck circuit so that the power supply device performs constant-current charging on the power battery; after the power battery is charged with constant current, when the voltage of the power battery reaches the constant-voltage charging voltage, the voltage-current dual closed-loop structure that controls the output voltage is used to control the multi-phase Buck circuit so that the power supply device performs constant-voltage charging on the power battery.

16. The control method of the charge and discharge device according to claim 15, characterized in that: The voltage-current dual closed-loop structure includes a voltage outer loop and multiple independent current inner loops, wherein the multiple current inner loops correspond one-to-one to the multi-phase Buck circuits; When a voltage-current dual closed-loop structure is used to control the multi-phase Buck circuit, compensation is also performed on the current of each phase in each current inner loop.

17. The control method of the charge and discharge device according to claim 16, characterized in that: When the number of Buck circuits is 3, the three-phase compensation current is obtained by the following formula: in, 、 、 They represent the three-phase compensation currents respectively, R1, R2, and R3 represent the parasitic resistances of the three-phase Buck circuit respectively, Vin represents the input voltage of the charging and discharging device, and i1, i2, and i3 represent the currents flowing through the three-phase Buck circuit respectively.

18. The control method of the charge and discharge device according to claim 15, characterized in that: Controlling the switch circuit and the multi-phase Buck circuit to enable the charging and discharging device to operate in a charging circulating current heating mode includes: Controlling the switch circuit so that the power supply device is connected to the power battery through the multi-phase Buck circuit; At least two control modes are used to control the multi-phase Buck circuits, so that the vector sum of the currents flowing through the multi-phase Buck circuits is the charging current.

19. The control method of the charge and discharge device according to claim 15, characterized in that: Controlling the switch circuit and the multi-phase Buck circuit to enable the charging and discharging device to operate in a direct charging mode includes: The switch circuit is controlled to connect the power supply device directly to the power battery.

20. The control method of the charge and discharge device according to claim 15, characterized in that: The multi-phase Buck circuit reuses at least two-phase bridge arms and at least two-phase motor windings of the vehicle motor drive circuit; controlling the switch circuit and the multi-phase Buck circuit to make the charging and discharging device operate in a non-charging circulating current heating mode, including: Controlling the switch circuit so that the bridge arms in the multi-phase Buck circuit are connected to the power battery; At least two control modes are used to control the multi-phase Buck circuits so that the vector sum of the currents flowing through the multi-phase Buck circuits is zero.

21. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method of the charging and discharging device according to any one of claims 15 to 20 is implemented.

22. An electronic device, characterized in that: include: at least one processor; A memory, wherein at least one program is stored in the memory, and when the at least one program is executed by at least one processor, the control method of the charging and discharging device according to any one of claims 15 to 20 is implemented.

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