Vehicle, charging system and control method thereof

Abstract

The present disclosure provides a vehicle, a charging system and a control method thereof. The charging system comprises M charging ports, a voltage conversion circuit, a controller and a battery pack, the M charging ports are connected to the battery pack through the voltage conversion circuit, M is an integer greater than 1, and the method comprises the following steps: obtaining charging demand information of the battery pack and output capability information of a charging device connected to the M charging ports; and controlling the voltage conversion circuit according to the charging demand information and the output capability information. The control method of the charging system can control the voltage conversion circuit to perform multi-gun charging according to the output capability of the charging device connected to the M charging ports through the setting of the voltage conversion circuit, thereby being compatible with charging devices of different maximum output voltage platforms to achieve fast charging, and further improving the charging efficiency and shortening the charging time.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of charging, in particular to a vehicle, a charging system and a control method thereof BACKGROUND

[0002] With the rapid development of new energy vehicles, the battery pack of the electric vehicle has higher and higher electric quantity and longer and longer driving range. Accordingly, the charging speed of the electric vehicle has become a problem that people pay more and more attention to. However, the charging system in the related art has the technical problem of low charging rate. SUMMARY

[0003] The present disclosure aims to at least partially solve one of the technical problems in the related art. To this end, a first object of the present disclosure is to provide a control method of a charging system to be compatible with charging devices of different maximum output voltage platforms so as to fast charge and thus improve charging efficiency and shorten charging time.

[0004] A second object of the present disclosure is to provide a charging system.

[0005] A third object of the present disclosure is to provide a vehicle.

[0006] To achieve the above objects, a control method of a charging system is provided in a first aspect of the present disclosure. The charging system includes M charging ports, a boost-buck circuit and a battery pack. The M charging ports are connected to the battery pack through the boost-buck circuit. M is an integer greater than 1. The method includes the following steps: obtaining charging demand information of the battery pack and output capability information of charging devices connected to the M charging ports; and controlling the boost-buck circuit according to the charging demand information and the output capability information.

[0007] The control method of the charging system of the present disclosure can be compatible with charging devices of different maximum output voltage platforms by controlling the boost-buck circuit to perform multi-gun charging according to the output capability of the charging devices connected to the M charging ports, so as to fast charge and thus improve charging efficiency and shorten charging time.

[0008] To achieve the above objects, a charging system is provided in a second aspect of the present disclosure. The charging system includes M charging ports, a boost-buck circuit, a controller and a battery pack. The M charging ports are connected to the battery pack through the boost-buck circuit. The controller is connected to the control end of the boost-buck circuit. The controller is configured to obtain charging demand information of the battery pack and output capability information of charging devices connected to the M charging ports, and control the boost-buck circuit according to the charging demand information and the output capability information. M is an integer greater than 1.

[0009] The charging system of the embodiment of the present disclosure can realize the output capability of the charging equipment connected with the M charging ports, control the step-up and step-down circuit to perform multi-gun charging, thereby being compatible with the charging equipment of different maximum output voltage platforms, so as to perform fast charging and further improve the charging efficiency and shorten the charging time.

[0010] To achieve the above object, the third aspect embodiment of the present disclosure provides a vehicle, which comprises the charging system of the first aspect embodiment.

[0011] The vehicle of the embodiment of the present disclosure can be compatible with the charging equipment of different maximum output voltage platforms, so as to perform fast charging and further improve the charging efficiency and shorten the charging time.

[0012] Additional aspects and advantages of the present disclosure will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a structural schematic diagram of the charging system of one embodiment of the present disclosure;

[0014] Figure 2 is a flowchart of the control method of the charging system of the embodiment of the present disclosure;

[0015] Figure 3 is a flowchart of step S22 of one embodiment of the present disclosure;

[0016] Figure 4 is a flowchart of the control method of the charging system of one example of the present disclosure;

[0017] Figure 5 is a flowchart of the control method of the charging system of another example of the present disclosure;

[0018] Figure 6 is a structural schematic diagram of the charging system of another embodiment of the present disclosure;

[0019] Figure 7 is a structural schematic diagram of the charging system of the first specific embodiment of the present disclosure;

[0020] Figure 8 is a structural schematic diagram of the charging system of the second specific embodiment of the present disclosure;

[0021] Figure 9 is a structural schematic diagram of the charging system of the third specific embodiment of the present disclosure;

[0022] Figure 10 is a structural schematic diagram of the charging system of the fourth specific embodiment of the present disclosure;

[0023] Figure 11 This is a schematic diagram of the charging system according to the fifth specific embodiment of this disclosure;

[0024] Figure 12 This is a schematic diagram of the charging system according to the sixth specific embodiment of this disclosure;

[0025] Figure 13 This is a schematic diagram of the first working stage of a charging system according to an embodiment of the present disclosure;

[0026] Figure 14 This is a schematic diagram of the second working stage of a charging system according to an embodiment of the present disclosure;

[0027] Figure 15 This is a schematic diagram of the first working stage of a charging system according to another embodiment of the present disclosure;

[0028] Figure 16 This is a schematic diagram of the second working stage of a charging system according to another embodiment of the present disclosure;

[0029] Figure 17 This is a flowchart of a charging system according to a specific embodiment of the present disclosure;

[0030] Figure 18 This is a structural block diagram of a vehicle according to an embodiment of the present disclosure. Detailed Implementation

[0031] Embodiments of this disclosure are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0032] The following description, with reference to the accompanying drawings, describes an embodiment of a vehicle, a charging system, and a control method thereof.

[0033] Figure 1 This is a schematic diagram of the structure of a charging system according to an embodiment of the present disclosure.

[0034] like Figure 1 As shown, the charging system of this embodiment includes: M charging ports ( Figure 1 Taking M=2 as an example, the two charging ports are denoted as the first charging port 1 and the second charging port 2, the step-up / step-down circuit 3 and the battery pack 5 respectively. All M charging ports are connected to the battery pack 5 through the step-up / step-down circuit 3, where M is an integer greater than 1.

[0035] Based on the above-described charging system, this disclosure proposes a control method for the charging system. Figure 2is a flowchart of a control method of a charging system according to an embodiment of the present disclosure.

[0036] As shown in Figure 2 , the control method of the charging system comprises:

[0037] S21, obtaining charging demand information of the battery pack and obtaining output capability information of the charging devices connected with the M charging ports.

[0038] S22, controlling the boost-buck circuit according to the charging demand information and the output capability information.

[0039] Specifically, the M charging ports are used to connect M charging guns, and the M charging guns can belong to N different charging devices respectively, where N≤M. When the battery pack 5 is charged through the M charging ports, the M charging ports are connected with the N charging devices through the M charging guns. At this time, the charging demand information (such as the charging demand voltage) of the battery pack 5 can be obtained, and the output capability information (such as the output maximum voltage, the output maximum current, etc.) of the N charging devices can be obtained. According to the charging demand information and the output capability information, the charging control mode (such as the single-gun full-on mode, the single-gun boost mode, the double-gun full-on mode, the double-gun boost mode, etc.) is determined, and the boost-buck circuit 3 is controlled (such as full-on control, boost-buck control, etc.) according to the charging control mode.

[0040] Therefore, the control method of the charging system according to the embodiment of the present disclosure can be compatible with charging devices of different maximum output voltage platforms. Whether the charging voltage range of the charging device connected with the charging port is lower than or higher than the maximum allowed charging voltage of the battery pack 5, the corresponding charging mode can be adopted to realize fast charging of the battery pack 5, thereby improving the charging efficiency and shortening the charging time.

[0041] In some embodiments, the charging system further comprises M switch circuits, the M switch circuits correspond to the M charging ports one by one, the switch circuit is connected between the boost-buck circuit and the corresponding charging port, the charging demand information comprises a demand charging voltage, and the output capability information comprises a maximum output voltage, or a maximum output voltage and a maximum output current.

[0042] In this embodiment, as shown in Figure 3 , the step S22 of controlling the boost-buck circuit according to the charging demand information and the output capability information comprises:

[0043] S31, when the maximum output voltages of the charging devices corresponding to the M charging ports are all greater than or equal to the demand charging voltage, controlling the M switch circuits to be all closed, and performing full-on control on the boost-buck circuit.

[0044] Specifically, if the highest output voltage of each charging device corresponding to each charging port is greater than or equal to the required charging voltage, it indicates that each charging device corresponding to each charging port can directly charge the battery pack, at this time, the M switch circuits can be controlled to be closed, and the boost-buck circuit is controlled to be fully open, and each charging device can output the required voltage to charge the battery pack. Thus, the charging speed can be improved by simultaneous charging of multiple guns.

[0045] In S32, when the highest output voltage of the M charging devices corresponding to the M charging ports is less than the required charging voltage, the M switch circuits are controlled to be closed, and the boost-buck circuit is controlled to be boosted.

[0046] Specifically, if the highest output voltage of each charging device corresponding to each charging port is less than the required charging voltage, it indicates that each charging device corresponding to each charging port cannot directly charge the battery pack alone, at this time, the M switch circuits can be controlled to be closed, and the boost-buck circuit is controlled to be boosted, and the output voltage of each charging device can reach the required voltage after being boosted to charge the battery pack. Thus, not only the charging device with small output capacity can charge the battery pack, but also multiple guns can be charged simultaneously, thereby improving the charging speed.

[0047] In S33, when at least one charging device corresponding to at least one charging port has a highest output voltage greater than or equal to the required charging voltage, and at least one charging device corresponding to at least one charging port has a highest output voltage less than the required charging voltage, the M switch circuits and the boost-buck circuit are controlled according to the required charging voltage, the highest output voltage and the highest output current of each charging device.

[0048] Specifically, if at least one charging device corresponding to at least one charging port has a highest output voltage greater than or equal to the required charging voltage, and at least one charging device corresponding to at least one charging port has a highest output voltage less than the required charging voltage, it indicates that some charging devices corresponding to some charging ports can directly charge the battery pack, while some cannot, at this time, the charging capacity of each charging device needs to be further judged when multiple guns are charged, to determine the control strategy of the boost-buck circuit and the open-close control of the switch circuit, so as to achieve better charging effect.

[0049] In one specific embodiment, the M charging ports include a first charging port and a second charging port, and the charging device connected to the first charging port is referred to as a first charging device, and the charging device connected to the second charging port is referred to as a second charging device.

[0050] In this specific embodiment, as an example, as shown in FIG. 1, the first charging device and the second charging device are connected to the first charging port and the second charging port respectively. Figure 4As shown, when the maximum output voltage of the first charging device is greater than or equal to the required charging voltage, and the maximum output voltage of the second charging device is less than the required charging voltage, according to the required charging voltage, the maximum output voltage and the maximum output current of each charging device, the M switch circuits and the boost-buck circuit are controlled, including:

[0051] S41, the first charging power is calculated according to the required charging voltage and the maximum output current of the first charging device, and the second charging power is calculated according to the maximum output current of the first charging device, the maximum output voltage and the maximum output current of the second charging device.

[0052] S42, when the first charging power is greater than the second charging power, the switch circuit corresponding to the first charging port is closed, the switch circuit corresponding to the second charging port is opened, and the boost-buck circuit is controlled to be fully on.

[0053] S43, when the first charging power is less than or equal to the second charging power, the switch circuits corresponding to the first charging port and the second charging port are both closed, and the boost-buck circuit is controlled to be boosted.

[0054] As another example, as shown, Figure 5 When the maximum output voltage of the first charging device is less than the required charging voltage, and the maximum output voltage of the second charging device is greater than or equal to the required charging voltage, according to the required charging voltage, the maximum output voltage and the maximum output current of each charging device, the M switch circuits and the boost-buck circuit are controlled, including:

[0055] S51, the third charging power is calculated according to the maximum output voltage and the maximum output current of the first charging device and the maximum output current of the second charging device, and the fourth charging power is calculated according to the required charging voltage and the maximum output current of the second charging device.

[0056] S52, when the third charging power is less than or equal to the fourth charging power, the switch circuit corresponding to the first charging port is opened, the switch circuit corresponding to the second charging port is closed, and the boost-buck circuit is controlled to be fully on.

[0057] S53, when the third charging power is greater than the fourth charging power, the switch circuits corresponding to the first charging port and the second charging port are both closed, and the boost-buck circuit is controlled to be boosted.

[0058] Specifically, let U0 be the required charging voltage of the battery pack, U1 be the maximum output voltage of the first charging device, U2 be the maximum output voltage of the second charging device, I1 be the maximum output current of the first charging device, and I2 be the maximum output current of the second charging device.

[0059] If U1 ≥ U0 and U2 < U0, then calculate the first charging power P1 = U0 * I1 and the second charging power P2 = U2 * (I1 + I2). If P1 > P2, it indicates that the first charging device has higher independent charging efficiency. In this case, the charging control mode can be determined as the first charging device being fully open and the second charging device not charging. This leads to the control of closing the switch circuit corresponding to the first charging port, opening the switch circuit corresponding to the second charging port, and fully opening the buck-boost circuit. If P1 ≤ P2, it indicates that dual-gun charging is more efficient. In this case, the charging control mode can be determined as the first and second charging devices simultaneously boosting the voltage. This leads to closing the switch circuits corresponding to both the first and second charging ports and boosting the voltage in the buck-boost circuit.

[0060] If U1 < U0 and U2 ≥ U0, then the third charging power P3 = U1 * (I1 + I2) and the fourth charging power P4 = U0 * I2. If P3 ≤ P4, it indicates that the second charging device alone has higher charging efficiency. In this case, the charging control mode can be determined as the second charging device being fully open and the first charging device not charging. This leads to the control of the switch circuit corresponding to the first charging port being open, the switch circuit corresponding to the second charging port being closed, and the buck-boost circuit being fully open. If P3 > P4, it indicates that dual-gun charging is more efficient. In this case, the charging control mode can be determined as the first and second charging devices simultaneously boosting the voltage. This leads to the control of the switch circuits corresponding to the first and second charging ports being closed, and the buck-boost circuit being boosted.

[0061] Optionally, when the charging device and the vehicle initiate a charging handshake, the charging device can obtain the charging demand voltage of the power battery; when the charging demand voltage is greater than the maximum output voltage Umax of the charging device, a step-down operation is performed by controlling the buck-boost circuit so that the voltage at the charging port is below the maximum output voltage of the charging device.

[0062] In summary, the control method of the charging system in this embodiment of the present disclosure, through the setting of the step-up and step-down circuit, can select different charging control modes according to the output capabilities of multiple charging devices, thereby enabling simultaneous fast charging of multiple charging guns for charging devices with different output voltage platforms. At the same time, it can select the charging method with the highest charging efficiency, which helps to improve charging efficiency and shorten charging time.

[0063] Figure 6 This is a schematic diagram of the structure of a charging system according to another embodiment of the present disclosure.

[0064] like Figure 6 As shown, the charging system of this embodiment includes: M charging ports ( Figure 1Taking M=2 as an example, two charging ports are respectively denoted as a first charging port 1 and a second charging port 2, a voltage conversion circuit 3, a controller 4 and a battery pack 5, where M is an integer greater than 1. The first end of each charging port is connected with a charging device, and the second end of each charging port is connected with the first end of the voltage conversion circuit 3; the battery pack 5 is connected with the second end of the voltage conversion circuit 3; the controller 4 is connected with the control end of the voltage conversion circuit 3, and the controller 4 is configured to: acquire charging demand information of the battery pack 5 and output capability information of the charging device corresponding to each charging port, and control the voltage conversion circuit 3 according to the charging demand information and the output capability information to perform multi-gun charging.

[0065] Therefore, the charging system can be compatible with charging devices of different maximum output voltage platforms, and no matter whether the charging voltage range of the charging device connected with the charging port is lower or higher than the maximum allowed charging voltage of the battery pack 5, the corresponding charging mode can be adopted to realize fast charging of the battery pack 5, thereby improving the charging efficiency and shortening the charging time.

[0066] Figure 7 is a structural schematic diagram of the charging system of the first specific embodiment of the present disclosure. As shown in Figure 7 , the voltage conversion circuit 3 includes N-phase bridge arms, N first inductors L1 and a first capacitor C1, where N is a positive integer. Figure 7 Taking N=1 as an example, the N-phase bridge arms correspond one-to-one to the N first inductors L1.

[0067] Referring to Figure 7 , each phase bridge arm is connected in parallel with the first capacitor C1, and the N-phase bridge arms are connected in parallel. The first bus end after the N-phase bridge arms are connected in parallel is connected with the positive electrode of the battery pack 5, and the second bus end after the N-phase bridge arms are connected in parallel is connected with the negative electrode of the battery pack 5, where N is a positive integer. The N first inductors L1 correspond one-to-one to the N-phase bridge arms. The first end of each first inductor L1 is connected with the midpoint of the corresponding bridge arm, the second end of each first inductor L1 is connected with the positive electrode of each charging port, and the negative electrode of each charging port is connected with the second bus end.

[0068] As an example, each phase bridge arm includes a first switch component and a second switch component, and the first switch component and the second switch component are connected in series. Referring to Figure 7 , the first switch component includes a first switch tube VT1 and a first diode VD1, and the second switch component includes a second switch tube VT2 and a second diode VD2. The first diode VD1 is connected in parallel with the first switch tube VT1, and the second diode VD2 is connected in parallel with the second switch tube VT2. The midpoint of each phase bridge arm is the connection point between the corresponding first switch tube VT1 and the second switch tube VT2.

[0069] In some embodiments of the present disclosure, referring to Figure 7The charging system can further comprise M switch circuits (61, 62, 63, 64) connected between the boost-buck circuit 3 and the M charging ports. Figure 2 Taking M=2 as an example, the two switch circuits are denoted as a first switch circuit 61 and a second switch circuit 62, respectively. The M switch circuits correspond to the M charging ports one by one, and are connected between the boost-buck circuit 3 and the corresponding charging port. In this embodiment, the controller 4 is further connected to the control terminals of the M switch circuits, and is configured to control the M switch circuits according to the charging control mode.

[0070] Specifically, referring to Figure 7 Taking M=2 as an example, the first switch circuit 61 corresponding to the first charging port 1 comprises a contactor K4 and a contactor K7, and the second switch circuit 61 corresponding to the second charging port 2 comprises a contactor K5 and a contactor K8. When the battery pack 5 needs to be charged through the first charging port 1, the controller 4 needs to control K4 and K7 to be closed; when the battery pack 5 needs to be charged through the second charging port 1, the controller 4 needs to control K5 and K6 to be closed. Meanwhile, the controller 4 can also control VT1 and VT2 to be turned on or off as needed to realize boost-buck charging of the battery pack 5.

[0071] As an example, referring to Figure 7 The charging system can further comprise a second capacitor C2 connected between the second end of the first inductor L1 and the second bus end, for filtering and stabilizing the charging voltage input by each charging port.

[0072] As an example, referring to Figure 7 The charging system can further comprise a main positive contactor K2 connected between the positive electrode of the battery pack 5 and the first bus end, and a pre-charge circuit 7 comprising a pre-charge contactor K3 and a pre-charge resistor R connected in series, and the pre-charge circuit is connected in parallel with the main positive contactor K2. Optionally, referring to Figure 2 The charging system can further comprise a main negative contactor K1 connected between the negative electrode of the battery pack 5 and the negative electrode of the boost-buck circuit 3.

[0073] Figure 8 The charging system of the second specific embodiment of the present disclosure is shown in the structural schematic diagram, Figure 9 The boost-buck circuit 3 of the third specific embodiment of the present disclosure is shown in the structural schematic diagram.

[0074] As shown in Figure 8 and Figure 9 The charging system further comprises a second inductor L2. Referring to Figure 8 The second inductor L2 is connected between the first inductor L1 and the positive electrode of the first charging port 1. Referring to Figure 9 The second inductor L2 is connected between the first inductor L1 and the positive electrode of the second charging port 2.

[0075] Therefore, by setting the second inductor L2, the circulating current that may occur when the maximum output current of the two charging devices connected to the two charging ports is simultaneously output can be inhibited.

[0076] In some embodiments of the present disclosure, the charging system is used for a vehicle, the N-phase bridge arms are multiplexed in the N-phase control bridge arms of the motor controller of the vehicle, and the N first inductors L1 are multiplexed in the N motor coil inductances of the vehicle.

[0077] Figure 10 is a structural schematic diagram of a charging system of a fourth specific embodiment of the present disclosure.

[0078] As shown in Figure 10 , when N is equal to 3, the three bridge arms are respectively denoted as a first bridge arm, a second bridge arm, and a third bridge arm, the first bridge arm is composed of a switch tube VT1, a switch tube VT2, a diode VD1, and a diode VD2, the second bridge arm is composed of a switch tube VT3, a switch tube VT4, a diode VD3, and a diode VD4, and the third bridge arm is composed of a switch tube VT5, a switch tube VT6, a diode VD5, and a diode VD6. Meanwhile, referring to Figure 5 , the three inductors connected with the three bridge arms can also multiplex the three motor coil inductances L3. Therefore, the charging system can reduce the use of devices by multiplexing the motor electric control components, thereby reducing the cost and reducing the occupied space of the charging system.

[0079] Optionally, referring to Figure 10 , the motor coil inductance L3 and the M switch circuits can be connected with a switching switch (such as a contactor K6 in Figure 10 ), and the second capacitor C2 is connected between the end of the contactor K6 away from L3 and the negative electrode of the voltage-lifting and voltage-lowering circuit 3. By setting the contactor K6, the motor electric control components can be multiplexed to the charging system without affecting the normal driving control of the motor electric control components. That is, when the vehicle is normally running, K6 is disconnected, L3 and the three bridge arms are used for driving control; when the vehicle stops charging, K6 is closed, and the charging of the charging system is implemented.

[0080] Figure 11 is a structural schematic diagram of a charging system of a fifth specific embodiment of the present disclosure, Figure 12 is a structural schematic diagram of a charging system of a sixth specific embodiment of the present disclosure.

[0081] Among them, Figure 11 , the difference between Figure 8 , the difference between Figure 12 , and Figure 9 is that the structures of the voltage-lifting and voltage-lowering circuits 3 are different, and the different structures of the voltage-lifting and voltage-lowering circuits 3 adopt the structure of the voltage-lifting and voltage-lowering circuit 3 shown in Figure 5 . As Figure 8 , Figure 9 ,Figure 11 、 Figure 12 In this way, by setting the second inductor L2, the circulating current that may occur when the two charging devices connected to the two charging ports simultaneously output the maximum current can be inhibited.

[0082] In some embodiments of the present disclosure, the charging demand information comprises a demand charging voltage, the output capability information comprises a maximum output voltage and a maximum output current, and the controller 4 is further configured to:

[0083] When the maximum output voltage of the charging device corresponding to each charging port is greater than or equal to the demand charging voltage, the M switch circuits are controlled to be closed, and the boost-buck circuit 3 is controlled to be fully open;

[0084] When the maximum output voltage of the charging device corresponding to each charging port is less than the demand charging voltage, the M switch circuits are controlled to be closed, and the boost-buck circuit 3 is controlled to be boosted;

[0085] Otherwise (i.e., at least one charging port corresponding to the charging device whose maximum output voltage is greater than or equal to the demand charging voltage, and at least one charging port corresponding to the charging device whose maximum output voltage is less than the demand charging voltage), the M switch circuits are controlled to be opened or closed according to the demand charging voltage, the maximum output voltage and the maximum output current, and the boost-buck circuit 3 is controlled.

[0086] In one specific embodiment, let the charging device connected to the first charging port 1 be the first charging device, and let the charging device connected to the second charging port 2 be the second charging device. The output capability information of the first charging device comprises a first maximum output voltage U1 and a first maximum output current I1, the capability information of the second charging device comprises a second maximum output voltage U2 and a second maximum output current I2, and the demand charging voltage is U0.

[0087] In this embodiment, as an example, the controller 4 is further configured to:

[0088] When the first maximum output voltage of the first charging device is greater than or equal to the required charging voltage, and the second maximum output voltage of the second charging device is less than the required charging voltage, i.e., U1≥U0, U2

[0089] As another example, the controller 4 is further configured to:

[0090] When the first maximum output voltage of the first charging device is less than the required charging voltage, and the second maximum output voltage of the second charging device is greater than or equal to the required charging voltage, i.e., U1

[0091] Specifically, the first charging device full-on control charging power and double-gun simultaneous boost control charging power judgment process is as follows:

[0092] The first charging power P1=U0*I1, the second charging power P2=U2*(I1+I2), if P1>P2, it is determined that the charging control mode is the first charging device full-on control and the second charging device does not charge; if P1≤P2, it is determined that the charging control mode is the first charging device and the second charging device simultaneous boost control.

[0093] The second charging device full-on control charging power and double-gun simultaneous boost control charging power judgment process is as follows:

[0094] The third charging power P3 is equal to U1*(I1+I2), and the fourth charging power P4 is equal to U0*I2. If P3≤P4, the charging control mode is determined as the second charging device full-on control and the first charging device no charging. If P3>P4, the charging control mode is determined as the first charging device and the second charging device simultaneous boost control.

[0095] Optionally, when the charging device and the vehicle charging handshake, the charging device can acquire the charging demand voltage of the power battery. When the charging demand voltage>the maximum output voltage Umax of the charging device, the step-down operation is performed by controlling the boost-buck circuit, so that the voltage of the charging port is below the maximum output voltage of the charging device.

[0096] The working principle of the charging system of the embodiment of the present disclosure will be described below Figures 13-16 with the example of the working principle of the charging system of the embodiment of the present disclosure, in which the charging voltage range of one of the two charging devices is lower than the highest allowable charging voltage of the battery pack 5, and the double-gun simultaneous boost charging is taken as an example:

[0097] Figure 13 FIG. 1 is a schematic diagram of working phase one of the charging system of one embodiment of the present disclosure, Figure 14 FIG. 2 is a schematic diagram of working phase two of the charging system of one embodiment of the present disclosure.

[0098] As shown in FIG. 1, in phase one of the charging process, the switch tube VT2 is controlled to be turned on, and the first charging circuit and the second charging circuit simultaneously charge the inductor L1. The current flow direction of the first charging circuit is: the positive pole of the first charging port 1→the contactor K7→the first inductor L1→the switch tube VT2→the contactor K4→the negative pole of the first charging port 1. The current flow direction of the second charging circuit is: the positive pole of the second charging port 2→the contactor K8→the inductor L1→the switch tube VT2→the contactor K5→the negative pole of the second charging port 2. Figure 13 As shown in FIG. 2, in phase two of the charging process, the switch tube VT2 is controlled to be turned off, and the first charging circuit and the second charging circuit simultaneously superimpose the voltage of the inductor L1 to charge the battery pack 5. The current flow direction of the first charging circuit is: the positive pole of the first charging port 1→the contactor K7→the inductor L1→the diode VD1→the contactor K2→the battery pack 5→the contactor K1→the contactor K4→the negative pole of the first charging port 1. The current flow direction of the second charging circuit is: the positive pole of the second charging port 2→the contactor K8→the inductor L1→the diode VD1→the contactor K2→the battery pack 5→the contactor K1→the contactor K5→the negative pole of the second charging port 2.

[0099] Figure 14 Thus, through the alternative control of phase one and phase two, boost conversion can be realized, thereby realizing the double-gun simultaneous boost charging.

[0100] Thus, through the alternative control of phase one and phase two, boost conversion can be realized, thereby realizing the double-gun simultaneous boost charging.

[0101] ​It should be noted that when the charging control mode is full-on control, the switch tube VT2 is not controlled to be turned on and turned off for boost conversion, and the current directly flows through the diode VD1 to charge the battery pack 5, and the current flow direction of the double-gun simultaneous charging is consistent with that shown in Figure 14

[0102] Figure 15 is a schematic diagram of working phase one of the charging system of another embodiment of the present disclosure, Figure 16 is a schematic diagram of working phase two of the charging system of another embodiment of the present disclosure.

[0103] As shown in Figure 15 , in phase one of the charging process, the switch tubes VT2, VT4 and VT6 are controlled to be turned on, and the first charging circuit and the second charging circuit simultaneously charge the motor coil inductor L3, the current flow direction of the first charging circuit is: the positive pole of the first charging port 1 → the contactor K7 → the contactor K6 → the motor coil inductor L3 → the switch tubes VT2, VT4 and VT6 → the contactor K4 → the negative pole of the first charging port 1, and the current flow direction of the second charging circuit is: the positive pole of the second charging port 2 → the contactor K8 → the contactor K6 → the inductor L3 → the switch tubes VT2, VT4 and VT6 → the contactor K5 → the negative pole of the second charging port 2.

[0104] As shown in Figure 16 , in phase two of the charging process, the switch tubes VT2, VT4 and VT6 are controlled to be turned off, and the first charging circuit and the second charging circuit simultaneously superimpose the voltage of the motor coil inductor L3 to charge the battery pack 5, the current flow direction of the first charging circuit is: the positive pole of the first charging port 1 → the contactor K7 → the contactor K6 → the motor coil inductor L3 → the diodes VD1, VD3 and VD5 → the contactor K2 → the battery pack 5 → the contactor K1 → the contactor K4 → the negative pole of the first charging port 1, and the current flow direction of the second charging circuit is: the positive pole of the second charging port 2 → the contactor K8 → the contactor K6 → the motor coil inductor L3 → the diodes VD1, VD3 and VD5 → the contactor K2 → the battery pack 5 → the contactor K1 → the contactor K5 → the negative pole of the second charging port 2.

[0105] Therefore, through the alternative control of phase one and phase two, boost conversion can be realized, so that double-gun simultaneous boost charging is realized.

[0106] It should be noted that when the charging control mode is full-on control, the switch tubes VT2, VT4 and VT6 are not controlled to be turned on and turned off for boost conversion, and the current directly flows through the diodes VD1, VD3 and VD5 to charge the battery pack 5, and the current flow direction of the double-gun simultaneous charging is consistent with that shown in Figure 16

[0107] The working process of the charging system of the embodiment of the present disclosure will be described below in combination with Figure 17 ​​​

[0108] Figure 17 is a workflow diagram of the charging system of one specific embodiment of the present disclosure.

[0109] In this embodiment, the charging gun connected with the first charging port 1 is the first charging gun, the charging gun connected with the second charging port is the second charging gun, and the first charging gun and the second charging gun belong to the first charging device and the second charging device respectively. Referring to Figure 17 , the working process of the charging system includes:

[0110] S1, detecting whether the first charging port is connected with the first charging gun, if yes, executing S2, otherwise, continuing to detect;

[0111] S2, performing charging handshake confirmation with the first charging device and obtaining the highest output voltage of the first charging device;

[0112] S3, judging whether the highest output voltage of the first charging device is higher than the highest allowable charging voltage of the battery pack, if yes, executing S4, otherwise, executing S5;

[0113] S4, full-on control of the first charging device, and turning to S6;

[0114] S5, boost control of the first charging device, and turning to S13;

[0115] S6, detecting whether the second charging port is connected with the second charging gun, if yes, executing S7, otherwise, continuing to detect;

[0116] S7, performing charging handshake confirmation with the second charging device and obtaining the highest output voltage of the second charging device;

[0117] S8, judging whether the highest output voltage of the second charging device is higher than the highest allowable charging voltage of the battery pack, if yes, executing S9, otherwise, executing S10;

[0118] S9, full-on control of the first charging device and the second charging device simultaneously;

[0119] S10, judging whether the full-on control charging power of the first charging device is greater than the dual-gun boost control charging power, if yes, executing S11, otherwise, executing S12;

[0120] S11, full-on control of the first charging device and no charging of the second charging device;

[0121] S12, boost control of the first charging device and the second charging device simultaneously;

[0122] S13, detecting whether the second charging port is connected with the second charging gun, if yes, executing S14, otherwise, continuing to detect;

[0123] S14, a charging handshake confirmation is performed with the second charging device, and the highest output voltage of the second charging device is obtained;

[0124] S15, it is judged whether the highest output voltage of the second charging device is higher than the highest allowed charging voltage of the battery pack, if yes, S16 is executed, otherwise, S12 is executed;

[0125] S16, it is judged whether the full-on control charging power of the second charging device is greater than the dual-gun boost control charging power, if yes, S17 is executed, otherwise, S12 is executed;

[0126] S17, the first charging device does not charge, and the second charging device is full-on controlled.

[0127] In summary, the charging system of the embodiment of the present disclosure can select different charging control modes according to the output capabilities of multiple charging devices through the setting of the boost-buck circuit, so as to simultaneously and quickly charge multiple guns of charging devices of different output voltage platforms, and can select the charging mode with the highest charging efficiency, which helps to improve the charging efficiency and shorten the charging time.

[0128] Figure 18 is a structural block diagram of a vehicle of the embodiment of the present disclosure.

[0129] As shown in Figure 18 , the vehicle 100 includes the charging system 10 of the above example.

[0130] The vehicle in the embodiment of the present disclosure can simultaneously and quickly charge multiple guns of charging devices of different output voltage platforms through the charging system of the above embodiment, and can select the charging mode with the highest charging efficiency, which helps to improve the charging efficiency and shorten the charging time.

[0131] It is to be appreciated that the above description and the examples that follow are intended to be illustrative only and that changes can be made to the description and examples without departing from the spirit and scope of the disclosure. Note also that the use of particular brand names in the description is solely for illustration and should not be construed as an endorsement of such brands.

[0132] It should be understood that aspects of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, and in another embodiment, any of the following techniques, which are well known in the art, can be used to implement the various techniques and procedures: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals; application specific integrated circuits having appropriate combinational logic gates; programmable gate arrays (PGA), field programmable gate arrays (FPGA), and other implementations known to those with skill in the art.

[0133] In the description of the present disclosure, reference has been made to descriptive terms such as "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" meant to

[0134] In the description of the present disclosure, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0135] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0136] In the present disclosure, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0137] In the present disclosure, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0138] Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as a limitation on the present disclosure, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present disclosure.

Claims

1. A control method for a charging system, characterized in that, The charging system includes M charging ports, a buck-boost circuit, and a battery pack. All M charging ports are connected to the battery pack via the buck-boost circuit, where M is an integer greater than 1. The method includes the following steps: Obtain the charging demand information of the battery pack, and obtain the output capacity information of the charging devices connected to the M charging ports; The buck-boost circuit is controlled based on the charging demand information and the output capability information. The charging system further includes M switching circuits, each corresponding to one of the M charging ports. The switching circuits are connected between the buck-boost circuit and the corresponding charging port. The charging demand information includes the required charging voltage, and the output capability information includes the maximum output voltage, or the maximum output voltage and the maximum output current. Controlling the buck-boost circuit based on the charging demand information and the output capability information includes: When the highest output voltage of the charging device corresponding to each of the M charging ports is greater than or equal to the required charging voltage, the M switching circuits are all closed, and the buck-boost circuit is fully opened. When the highest output voltage of the charging device corresponding to each of the M charging ports is less than the required charging voltage, the M switching circuits are all closed, and the boost / buck circuit is boosted. When the highest output voltage of the charging device corresponding to at least one charging port is greater than or equal to the required charging voltage, and the highest output voltage of the charging device corresponding to at least one charging port is less than the required charging voltage, the M switching circuits and the buck-boost circuit are controlled according to the required charging voltage, the highest output voltage of each charging device, and the highest output current.

2. The control method for the charging system as described in claim 1, characterized in that, The M charging ports include a first charging port and a second charging port. The charging device connected to the first charging port is designated as the first charging device, and the charging device connected to the second charging port is designated as the second charging device. The condition is met when the highest output voltage of the first charging device is greater than or equal to the required charging voltage, and the highest output voltage of the second charging device is less than the required charging voltage. The first charging power is calculated based on the required charging voltage and the maximum output current of the first charging device, and the second charging power is calculated based on the maximum output current of the first charging device, the maximum output voltage of the second charging device, and the maximum output current of the second charging device. When the first charging power is greater than the second charging power, the switch circuit corresponding to the first charging port is closed, the switch circuit corresponding to the second charging port is opened, and the buck-boost circuit is fully opened. When the first charging power is less than or equal to the second charging power, the switch circuits corresponding to the first charging port and the second charging port are closed, and the boost / buck circuit is boosted.

3. The control method for the charging system as described in claim 2, characterized in that, When the highest output voltage of the first charging device is less than the required charging voltage, and the highest output voltage of the second charging device is greater than or equal to the required charging voltage. The third charging power is calculated based on the highest output voltage and highest output current of the first charging device and the highest output current of the second charging device, and the fourth charging power is calculated based on the required charging voltage and the highest output current of the second charging device. When the third charging power is less than or equal to the fourth charging power, the switch circuit corresponding to the first charging port is opened, the switch circuit corresponding to the second charging port is closed, and the buck-boost circuit is fully opened. When the third charging power is greater than the fourth charging power, the switch circuits corresponding to the first charging port and the second charging port are closed, and the boost / buck circuit is boosted.

4. A charging system for implementing the control method of the charging system as described in claims 1-3, characterized in that, The charging system includes: The system comprises M charging ports, a buck-boost circuit, a controller, and a battery pack. The M charging ports are all connected to the battery pack through the buck-boost circuit. The controller is connected to the control terminal of the buck-boost circuit and is used to obtain the charging demand information of the battery pack and the output capability information of the charging devices connected to the M charging ports. The controller controls the buck-boost circuit according to the charging demand information and the output capability information, where M is an integer greater than 1.

5. The charging system as described in claim 4, characterized in that, The buck-boost circuit includes: First capacitor; N-phase bridge arms, each phase of the bridge arm is connected in parallel with the first capacitor, the N-phase bridge arms are connected in parallel, the first bus terminal of the N-phase bridge arms after parallel connection is connected to the positive terminal of the battery pack, and the second bus terminal of the N-phase bridge arms after parallel connection is connected to the negative terminal of the battery pack, where N is a positive integer; There are N first inductors, each corresponding to one of the N phase bridge arms. The first end of each first inductor is connected to the midpoint of the corresponding bridge arm, the second end of each first inductor is connected to the positive terminal of each charging port, and the negative terminal of each charging port is connected to the second bus terminal.

6. The charging system as described in claim 5, characterized in that, Each phase arm includes a first switch assembly and a second switch assembly, wherein the first switch assembly and the second switch assembly are connected in series. The first switching assembly includes a first switching transistor and a first diode, wherein the first diode is connected in parallel with the first switching transistor; The second switching assembly includes a second switching transistor and a second diode, wherein the second diode is connected in parallel with the second switching transistor; The controller is connected to the control terminals of the first switch and the second switch, and is used to control the on / off state of the first switch and the second switch.

7. The charging system as described in claim 5, characterized in that, The charging system also includes M switching circuits, each of which corresponds to one of the M charging ports. The switching circuits are connected between the step-up / step-down circuit and the corresponding charging port. The second capacitor is connected between the second terminal of the first inductor and the second bus terminal; wherein, the controller is also connected to the control terminal of the M switching circuits for controlling the M switching circuits.

8. The charging system as described in claim 5, characterized in that, The charging system also includes: A main positive contactor is connected between the positive terminal of the battery pack and the first bus terminal; The pre-charging circuit includes a pre-charging contactor and a pre-charging resistor connected in series, and the pre-charging circuit is connected in parallel with the main positive contactor.

9. The charging system as described in claim 5, characterized in that, The N-phase bridge arm reuses the N control bridge arms in the motor controller of the vehicle, and the N first inductors reuse the N motor coil inductors of the vehicle.

10. The charging system as described in claim 7, characterized in that, The M charging ports include a first charging port and a second charging port, and the charging system further includes: The second inductor is connected between the first inductor and the positive terminal of the first charging port, or the second inductor is connected between the first inductor and the positive terminal of the second charging port.

11. A vehicle, characterized in that, Including the charging system as described in claims 4-10.

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