Charging control method, charging module and charging system

Abstract

The invention discloses a charging control method, a charging module and a charging system, and the method comprises the steps: controlling a relay combination circuit to be in a first control state when an AC / DC unit is started and a DC / DC unit is not started, so as to enable an output circuit and a load to be in an open circuit state; and when the DC / DC unit is started, the relay combination circuit is controlled to be in a second control state, so that the output circuits are connected in parallel or in series to meet the required voltage of the load. According to the charging module, the technical problem that the failure of the anti-reverse diode in the existing charging module may cause the burst and damage of the electrolytic capacitor is solved, and the technical effects that the electrolytic capacitor protection is realized in different working stages of the charging module through the relay combination control, and the burst and damage of the electrolytic capacitor caused by the failure of the anti-reverse diode are prevented are achieved.

Description

Technical Field

[0001] This application relates to the field of charging control, and particularly to a charging control method, a charging module, and a charging system. Background Art

[0002] In a charging module, an anti-reverse diode is an important protection component, and its main function is to prevent the high voltage of the subsequent load from being reverse-fed to the charging module. There are potential safety hazards in the existing charging modules when the anti-reverse diode fails. In the case of the anti-reverse diode being damaged, the high voltage of the subsequent load will directly be reverse-fed to the electrolytic capacitor. For example, if the high voltage of the subsequent load is 1000V and the withstand voltage of the electrolytic capacitor is 500V or 525V, when the anti-reverse diode is damaged, the high voltage of 1000V of the subsequent load will directly be reverse-fed to the electrolytic capacitor with a withstand voltage of only 500V or 525V, resulting in the bursting of the electrolytic capacitor, splashing of the electrolyte, and even causing the charging module to catch fire, presenting serious safety hazards.

[0003] Therefore, although an anti-reverse diode is added in the charging module to prevent high-voltage reverse feeding, once the anti-reverse diode fails, it cannot effectively protect the electrolytic capacitor, thus making the charging module at risk of secondary damage and affecting the safety and reliability of the charging system. Summary of the Invention

[0004] The main objective of this application is to provide a charging control method, a charging module, and a charging system, aiming to solve the technical problem that the failure of the anti-reverse diode in the existing charging module may cause the electrolytic capacitor to burst and be damaged.

[0005] To achieve the above objective, this application provides a charging control method for a charging module. The charging module includes a cascaded AC / DC unit and a DC / DC unit. The DC / DC unit includes a plurality of output circuits, and each output circuit is connected to a load through a relay combination circuit. The method includes: when the AC / DC unit starts and the DC / DC unit has not started, controlling the relay combination circuit to be in a first control state so that the output circuit and the load are in an open-circuit state; when the DC / DC unit starts, controlling the relay combination circuit to be in a second control state so that each output circuit is connected in parallel or in series to meet the required voltage of the load.

[0006] Optionally, a plurality of the output circuits include a first output circuit and a second output circuit, the relay combination circuit includes a first relay, a second relay, and a third relay, the first relay is connected between the negative output terminal of the first output circuit and the negative output terminal of the second output circuit, the third relay is connected between the positive output terminal of the first output circuit and the positive output terminal of the second output circuit, and the second relay is connected between the positive output terminal of the first output circuit and the negative output terminal of the second output circuit.

[0007] Optionally, controlling the relay combination circuit to be in a first control state, or controlling the first relay and the third relay to be disconnected and controlling the second relay to be closed.

[0008] Optionally, controlling the relay combination circuit to be in a second control state includes: obtaining the maximum output voltage of each output circuit; when the required voltage of the load is less than or equal to the maximum output voltage, controlling the first relay and the third relay to be closed and controlling the second relay to be disconnected; when the required voltage of the load is greater than the maximum output voltage, controlling the first relay and the third relay to be disconnected and controlling the second relay to be closed.

[0009] Optionally, a plurality of the output circuits include a first output circuit and a second output circuit, the relay combination circuit includes a first relay and a second relay, the first relay is connected between the negative output terminal of the first output circuit and the negative output terminal of the second output circuit, and the second relay is connected between the positive output terminal of the first output circuit and the negative output terminal of the second output circuit.

[0010] Optionally, controlling the relay combination circuit to be in a first control state includes: controlling both the first relay and the second relay to be disconnected.

[0011] Optionally, controlling the relay combination circuit to be in a second control state includes: obtaining the maximum output voltage of each output circuit; when the required voltage of the load is less than or equal to the maximum output voltage, controlling the first relay to be closed and controlling the second relay to be disconnected; when the required voltage of the load is greater than the maximum output voltage, controlling the first relay to be disconnected and controlling the second relay to be closed.

[0012] Optionally, the DC / DC unit further includes an anti-reverse circuit. The relay combination circuit is connected to the load through the anti-reverse circuit, and voltage sampling circuits are provided at both the input end and the output end of the anti-reverse circuit. The method further includes: controlling the DC / DC unit to be in a first preset state; performing a first state detection on the anti-reverse circuit based on the sampled voltages of the voltage sampling circuits; if the result of the first state detection fails to determine the state of the anti-reverse circuit, controlling the DC / DC unit to be in a second preset state, and performing a second state detection on the anti-reverse circuit based on the current sampled voltages of the voltage sampling circuits and determining the state of the anti-reverse circuit.

[0013] In addition, to achieve the above object, the present application further provides a charging module, including a controller for implementing the charging control method described above.

[0014] In addition, the present application further provides a charging system, including at least two charging modules as described in claim 9, at least one charging interface, a control center, and a power distribution device; the power distribution device is respectively connected to the control center, each of the charging modules, and each of the charging interfaces. Among them, each of the charging modules is used to convert the alternating current of the power grid into direct current and provide it to each of the charging interfaces; the control center is used to obtain the required power of each charging interface, and generate a scheduling instruction according to the connection relationship of the controllable switches in the power distribution device and each required power; the power distribution device is used to control the opening or closing of the controllable switches according to the scheduling instruction to distribute the output power of each charging module to each charging interface.

[0015] The beneficial effects that the present application can achieve are as follows:

[0016] By controlling the state of the relay combination circuit in different working stages of the charging module, the technical problem in the prior art that the anti-reverse diode failure of the charging module may cause the electrolytic capacitor to burst and be damaged is solved. First, when the AC / DC unit starts and the DC / DC unit does not start, the relay combination circuit is controlled to be in a first control state, so that the output circuit and the load are in an open circuit state. In this way, even if the anti-reverse diode fails, the external high voltage cannot directly act on the electrolytic capacitor, realizing the protection of the electrolytic capacitor. When the DC / DC unit starts, the relay combination circuit is controlled to be in a second control state, so that the output circuits are connected in parallel or in series to meet the required voltage of the load. By controlling the relay combination circuit to connect the output circuits in parallel or in series when the DC / DC unit starts, the protection of the electrolytic capacitor is maintained during the normal operation of the charging module.

[0017] By performing specific state control on the relay combination circuit in different working stages of the charger, even if the anti-reverse diode fails, the electrolytic capacitor can be prevented from being directly impacted by external high voltage, realizing the protection of the electrolytic capacitor in the charging module and improving the safety and reliability of the charging system. Description of the Drawings

[0018] Figure 1 Schematic diagram of the circuit structure of the first charging module provided by this application;

[0019] Figure 2 Schematic diagram of the circuit structure of the second charging module provided by this application;

[0020] Figure 3 Schematic diagram of the flow of a charging control method provided by this application;

[0021] Figure 4 Schematic diagram of the structure with a voltage sampling circuit in the circuit structure of the first charging module provided by this application;

[0022] Figure 5 Schematic diagram of the structure with a voltage sampling circuit in the circuit structure of the second charging module provided by this application;

[0023] Figure 6 Flowchart of the first anti-reverse circuit detection provided by the present invention;

[0024] Figure 7 Flowchart of the second anti-reverse circuit detection provided by the present invention;

[0025] Figure 8 Flowchart of the third anti-reverse circuit detection provided by the present invention;

[0026] Figure 9 Schematic diagram of the structure of the charging system provided by the present invention.

[0027] The realization of the purpose of this application, functional features and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain preset posture (as shown in the attached drawings). If the preset posture changes, the directional indications will also change accordingly.

[0030] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0032] First, the circuit structure of the charging module involved in the present application will be introduced below.

[0033] Figure 1 It is a schematic diagram of the circuit structure of the charging module provided in an embodiment of the present application. Refer to Figure 1, the charging module includes an AC / DC unit and a DC / DC unit. Among them, the DC / DC unit includes two output circuits, namely the lower output circuit (i.e., the first output circuit) and the upper output circuit (i.e., the second output circuit). The upper output circuit consists of a main transformer 1, a rectifying circuit (formed by diodes D1, D2, D3, and D4), and an electrolytic capacitor C2. The lower output circuit consists of a main transformer 2, a rectifying circuit (formed by diodes D5, D6, D7, and D8), and an electrolytic capacitor C1. The two output circuits are connected to the load through a relay combination circuit, which includes three relays, namely the first relay RLY1, the second relay RLY2, and the third relay RLY3. Among them, the first relay RLY1 is connected between the negative output terminal of the lower output circuit and the negative output terminal of the upper output circuit. The third relay RLY3 is connected between the positive output terminal of the lower output circuit and the positive output terminal of the upper output circuit. The second relay RLY2 is connected between the positive output terminal of the lower output circuit and the negative output terminal of the upper output circuit. After the relay combination circuit, an anti-reverse circuit is connected. The anti-reverse circuit includes an anti-reverse diode D10, and the output terminals of the lower output circuit and the upper output circuit are commonly connected to the anti-reverse diode D10. The anti-reverse diode D10 is used to protect against voltage backflow of the battery load to protect the electrolytic capacitors C1 and C2.

[0034] Figure 2 is a schematic circuit diagram of the charging module provided by another embodiment of the present application. Refer to Figure 2 , the charging module includes an AC / DC unit and a DC / DC unit. Among them, the DC / DC unit includes two output circuits, namely the lower output circuit (i.e., the first output circuit) and the upper output circuit (i.e., the second output circuit). After the upper output circuit and the lower output circuit, a relay combination circuit and an anti-reverse circuit are connected. Different from Figure 1 the charging module described above: the relay combination circuit includes two relays, namely the first relay RLY1 and the second relay RLY2; the anti-reverse circuit includes an anti-reverse diode D9 and an anti-reverse diode D10. Among them, the first relay RLY1 is connected between the negative output terminal of the upper output circuit and the negative output terminal of the lower output circuit. The second relay RLY2 is connected between the positive output terminal of the upper output circuit and the negative output terminal of the lower output circuit; the anti-reverse circuit includes an anti-reverse diode D9 and an anti-reverse diode D10. Specifically, the output terminal of the lower output circuit is connected to the anti-reverse diode D9, and the output terminal of the upper output circuit is connected to the anti-reverse diode D10. The anti-reverse diode D9 is used to prevent voltage backflow of the battery load to protect the electrolytic capacitor C1; the anti-reverse diode D10 is used to prevent voltage backflow of the battery load to protect the electrolytic capacitor C2.

[0035] The charging control method provided by the present application will be introduced below.Figure 3 The flowchart of the charging control method provided by an embodiment of the present application is as follows Figure 3 As shown, the method may include the following steps:

[0036] S1: When the AC / DC unit is started and the DC / DC unit is not started, control the relay combination circuit to be in the first control state, so that the output circuit and the load are in an open circuit state;

[0037] S2: When the DC / DC unit is started, control the relay combination circuit to be in the second control state, so that the output circuits are connected in parallel or in series to meet the required voltage of the load.

[0038] Specifically, when the AC / DC unit of the charging module is started and the DC / DC unit is not started, control the relay combination circuit to be in the first control state. This first control state can make the output circuit and the load in an open circuit state. By controlling the relay combination circuit in a specific state when the AC / DC unit of the charging module is started and the DC / DC unit is not started, and making the output circuit and the load in an open circuit state, damage to the electrolytic capacitor caused by the high voltage of the external load can be prevented.

[0039] When the DC / DC unit of the charging module is started, control the relay combination circuit to be in the second control state. This second control state can, according to the required voltage of the load, connect the output circuits in series or in parallel, so that the charging module meets the required voltage of the load. By dynamically adjusting the state of the relay combination circuit according to the required voltage of the load, the protection of the electrolytic capacitor can still be maintained when the charging module is working normally.

[0040] By controlling the relay combination circuit in different working states of the charging module, effective protection of the electrolytic capacitor in the charging module is achieved, and damage to the electrolytic capacitor caused by the failure of the anti - reverse diode is avoided.

[0041] As an optional implementation manner, controlling the relay combination circuit to be in the first control state includes:

[0042] S11: Control the first relay, the second relay, and the third relay to be all disconnected, or control the first relay and the third relay to be disconnected, and control the second relay to be closed.

[0043] Specifically, controlling the relay combination circuit to be in the first control state can be two states. One is to control the first relay, the second relay, and the third relay to be all disconnected; the other is to control the first relay and the third relay to be disconnected, and control the second relay to be closed.

[0044] For the first control state in which the first relay, the second relay, and the third relay are all turned off. By setting the relays in all relay combination circuits to the off state, complete isolation between the output circuit of the charging module and the load can be achieved. Even if a load is connected to the charging module, since there is no loop formed between the external load and the electrolytic capacitor, the high voltage on the external load battery will not be applied to the electrolytic capacitor, and the electrolytic capacitor will not be damaged due to overvoltage.

[0045] Refer to Figure 1 , when the charging module starts to work, the AC / DC unit of the charging module is turned on. There is AC input on the AC side, and the AC / DC unit rectifies the input AC into DC. At this time, the PFC bus voltage is about 550V, and the auxiliary power supply starts to work, and the relay on the AC side closes. After the control background executes the AC side power-on instruction, the controller on the AC side works, the AC side drives to generate waves, and the PFC bus is established to about 800V DC, and the relay on the AC side remains closed. When the control background does not execute the power-on of the DC / DC unit, the controller on the DC side does not generate waves, the switching tubes on the DC side do not work, and there is no DC output on the DC side. In this case, the AC / DC unit of the charging module is started and the DC / DC unit is not started. At this time, the control relay combination circuit is in the first control state, that is, the first relay RLY1, the second relay RLY2, and the third relay RLY3 are all turned off. In this way, when the load contactor closes to connect an external load, even if the reverse protection diode D10 is damaged by direct conduction, since all relays are in the off state, there will be no loop formed between the external load and the electrolytic capacitor of the charging module. Therefore, the high voltage of the external load will not be applied to the electrolytic capacitors C1 and C2, thus avoiding overvoltage damage to the electrolytic capacitors C1 and C2.

[0046] For the first control state in which the first relay and the third relay are turned off, and the second relay is turned on. Through this control method of relay combination, the series connection of multiple output circuits is realized, so that the high voltage of the external load can be withstood.

[0047] Refer to Figure 1, when the AC / DC unit of the charging module starts and the DC / DC unit does not start, control the first relay RLY1 and the third relay RLY3 to disconnect, and control the second relay RLY2 to close. By closing the second relay RLY2, the lower output circuit (the first output circuit) and the upper output circuit (the second output circuit) are connected in series. Assume that the withstand voltage of the electrolytic capacitors in each output circuit of the lower output circuit and the upper output circuit of this charging module is 525V, and the total withstand voltage after the two output circuits are connected in series can reach 1050V; the highest voltage after the external battery load of this charging module is fully charged is 1000V. In this state, even if the anti-reverse diode D10 is damaged by direct conduction, since the total withstand voltage after the two output circuits are connected in series can reach 1050V, it can still withstand the high voltage of the external load (not exceeding 1000V), thereby avoiding overvoltage damage to the electrolytic capacitors C1 and C2 in the charging module.

[0048] As an alternative embodiment, controlling the relay combination circuit to be in the second control state includes:

[0049] S21: Obtain the maximum output voltage of each output circuit;

[0050] S22: When the required voltage of the load is less than or equal to the maximum output voltage, control the first relay and the third relay to close, and control the second relay to disconnect;

[0051] S23: When the required voltage of the load is greater than the maximum output voltage, control the first relay and the third relay to disconnect, and control the second relay to close.

[0052] Specifically, when the DC / DC unit starts, control the relay combination circuit to be in the corresponding second control state according to the required voltage of the load, so that each output circuit is connected in parallel or in series, thereby meeting the required voltage of the load.

[0053] First, obtain the maximum output voltage of each output circuit. Then, compare the required voltage of the load with the maximum output voltage of each output circuit. If the required voltage of the load is less than or equal to the maximum output voltage, control the first relay and the third relay to close, and at the same time control the second relay to disconnect, so that the first output circuit and the second output circuit operate in parallel. If the required voltage of the load is greater than the maximum output voltage, control the first relay and the third relay to disconnect, and at the same time control the second relay to close, so that the first output circuit and the second output circuit operate in series.

[0054] Refer to Figure 1, the maximum output voltage of each output circuit in the charging module is 505V. When the DC / DC unit of the charging module starts, if the required voltage of the load is less than or equal to the maximum output voltage, the first relay RLY1 and the third relay RLY3 are controlled to close, and the second relay RLY2 is controlled to open, so that the lower output circuit (the first output circuit) and the upper output circuit (the second output circuit) work in parallel; if the required voltage of the load is greater than the maximum output voltage, the first relay RLY1 and the third relay RLY3 are controlled to open, and the second relay RLY2 is controlled to close, so that the lower output circuit (the first output circuit) and the upper output circuit (the second output circuit) work in series. By controlling the relay combination circuit according to the different required voltages of the load, the output voltage of the charging module is greater than or equal to the required voltage of the load, avoiding the impact of the external load on the electrolytic capacitors C1 and C2 in the case of the failure of the anti-reverse diode D10.

[0055] By switching the relay combination circuit according to the required voltage of the load, the connection mode of each output circuit can be flexibly adjusted under different required voltages of the load, ensuring the normal operation of the charging module and realizing the protection of the electrolytic capacitor at the same time.

[0056] As an optional implementation manner, controlling the relay combination circuit to be in the first control state includes:

[0057] S11: Control both the first relay and the second relay to open.

[0058] Specifically, controlling the relay combination circuit to be in the first control state is: controlling both the first relay and the second relay to open. By setting all the relays in the relay combination circuit to the open state, the complete isolation between the output circuit of the charging module and the load can be achieved. Even if a load is connected to the charging module, since there is no loop formed between the external load and the electrolytic capacitor, the high voltage on the external load battery will not be applied to the electrolytic capacitor, and the electrolytic capacitor will not be damaged due to overvoltage.

[0059] Refer to Figure 2, when the charging module starts to work, the AC / DC unit of the charging module is turned on. There is AC input on the AC side, and the AC / DC unit rectifies the input AC into DC. At this time, the PFC bus voltage is about 550V, the auxiliary power supply starts to work, and the relay on the AC side closes. When the control background executes the AC side startup instruction, the controller on the AC side works, the AC side drives to generate waves, and the PFC bus is built up to about 800V DC, and the relay on the AC side remains closed. When the control background does not execute the DC / DC unit startup, the controller on the DC side does not generate waves, the switching tubes on the DC side do not work, and there is no DC output on the DC side. In this case, the AC / DC unit of the charging module starts and the DC / DC unit does not start. At this time, the control relay combination circuit is in the first control state, that is, both the first relay RLY1 and the second relay RLY2 are controlled to be disconnected. In this way, when the load contactor closes to connect the external load, even if the anti-reverse diode D9 or the anti-reverse diode D10 is damaged by direct connection, since all relays are in the disconnected state, no loop will be formed between the external load and the electrolytic capacitors of the charging module. Therefore, the high voltage of the external load will not be applied to the electrolytic capacitors C1 and C2, thus avoiding overvoltage damage to the electrolytic capacitors.

[0060] As an alternative embodiment, controlling the relay combination circuit to be in the second control state includes:

[0061] S21: Obtain the maximum output voltage of each output circuit;

[0062] S22: When the required voltage of the load is less than or equal to the maximum output voltage, control the first relay to close and control the second relay to open;

[0063] S23: When the required voltage of the load is greater than the maximum output voltage, control the first relay to open and control the second relay to close.

[0064] Specifically, when the DC / DC unit starts, the relay combination circuit is controlled to be in the second control state according to the required voltage of the load, so that each output circuit is connected in parallel or in series to meet the required voltage of the load.

[0065] First, obtain the maximum output voltage of each output circuit. Then, compare the required voltage of the load with the maximum output voltage of each output circuit. If the required voltage of the load is less than or equal to the maximum output voltage of each output circuit, control the first relay to close and control the second relay to open at the same time, so that the first output circuit and the second output circuit operate in parallel. If the required voltage of the load is greater than the maximum output voltage of each output circuit, control the first relay to open and control the second relay to close at the same time, so that the first output circuit and the second output circuit operate in series.

[0066] Reference Figure 2 , the maximum output voltage of each output circuit of the charging module is 505V. When the DC / DC unit of the charging module starts, if the required voltage of the load is less than or equal to the maximum output voltage of each output circuit, the first relay RLY1 is controlled to close, and at the same time, the second relay RLY2 is controlled to open, so that the lower output circuit (the first output circuit) and the upper output circuit (the second output circuit) work in parallel, so that the output voltage of the charging module is less than 505V, meeting the required voltage of the load; if the required voltage of the load is greater than the maximum output voltage of each output circuit, the first relay RLY1 is controlled to open, and at the same time, the second relay RLY2 is controlled to close, so that the lower output circuit (the first output circuit) and the upper output circuit (the second output circuit) work in series, so that the output voltage of the charging module is greater than 505V, meeting the required voltage of the load. By controlling the relay combination circuit according to the different required voltages of the load, the output voltage of the charging module is greater than or equal to the required voltage of the load, avoiding the impact of the external load on the electrolytic capacitor C1 or C2 in the case of the failure of the anti-reverse diode D9 or the anti-reverse diode D10.

[0067] By switching the state of the relay combination circuit according to the required voltage of the load, the connection mode of the output circuit can be flexibly adjusted under different required voltages of the load, ensuring the normal operation of the charging module and realizing the protection of the electrolytic capacitor at the same time.

[0068] As an optional implementation manner, the DC / DC unit further includes an anti-reverse circuit, the relay combination circuit is connected to the load through the anti-reverse circuit, and voltage sampling circuits are arranged at both the input end and the output end of the anti-reverse circuit; the method further includes:

[0069] S3: Control the DC / DC unit to be in the first preset state;

[0070] S4: Perform the first state detection on the anti-reverse circuit based on the sampling voltages of the voltage sampling circuits;

[0071] S5: If the result of the first state detection fails to determine the state of the anti-reverse circuit, control the DC / DC unit to be in the second preset state, and perform the second state detection on the anti-reverse circuit based on the current sampling voltages of the voltage sampling circuits and determine the state of the anti-reverse circuit.

[0072] Specifically, the DC / DC unit further includes an anti-reverse circuit, as shown in Figure 4 and Figure 5 , voltage sampling circuits are arranged at both the input end and the output end of the anti-reverse circuit. Refer to Figure 4, the voltage sampling circuit includes voltage sampling circuit 1, voltage sampling circuit 2, and voltage sampling circuit 3. Voltage sampling circuit 1 and voltage sampling circuit 2 are arranged at the input end of the reverse protection circuit and are used to collect the input voltage of reverse protection diode D10; voltage sampling circuit 3 is arranged at the output end of the reverse protection circuit and is used to collect the output voltage of reverse protection diode D10. Refer to Figure 5 , the voltage sampling circuit includes voltage sampling circuit 1, voltage sampling circuit 2, and voltage sampling circuit 3. Voltage sampling circuit 1 is arranged at the input end of reverse protection diode D9 and is used to collect the input voltage of reverse protection diode D9; voltage sampling circuit 2 is arranged at the input end of reverse protection diode D10 and is used to collect the input voltage of reverse protection diode D10; voltage sampling circuit 3 is arranged at the output end of the reverse protection circuit and is used to collect the output voltages of reverse protection diodes D9 and D10.

[0073] During the detection process of the reverse protection circuit, first, control the DC / DC unit to enter the first preset state to set a specific working state and create conditions for the state detection of the reverse protection circuit. Then, in the first preset state, perform voltage collection through each voltage sampling circuit to obtain the sampling voltages of each voltage sampling circuit. Subsequently, perform the first state detection on the reverse protection circuit according to the sampling voltages of each voltage sampling circuit. By collecting and analyzing the voltage values before and after the reverse protection circuit, preliminarily judge the working state of the reverse protection circuit. If the result of the first state detection fails to determine the state of the reverse protection circuit, then switch the DC / DC unit to the second preset state, and perform voltage collection through each voltage sampling circuit again to obtain the current sampling voltages of each voltage sampling circuit. After that, perform the second state detection on the reverse protection circuit based on the current sampling voltages of each voltage sampling circuit, thereby determining the state of the reverse protection circuit.

[0074] By arranging voltage sampling circuits at the input and output ends of the reverse protection circuit and performing multiple state detections under different preset states, the accurate judgment of the state of the reverse protection circuit is realized, thereby further preventing the electrolytic capacitor from bursting and being damaged due to the failure of the reverse protection diode.

[0075] The following combines Figure 4 and Figure 5 the circuit structure of the charging module shown, as well as Figure 6 , Figure 7 , Figure 8 the reverse protection circuit detection flowcharts of

[0076] to specifically illustrate how to determine the state of the reverse protection circuit in the charging module. Figure 6 Refer to the reverse protection circuit detection flowchart shown. This reverse protection circuit detection process can be used to detect the reverse protection circuit in the charging module shown in Figure 4 and Figure 5 .

[0077] For Figure 4 the charging module shown Figure 6 the anti-reverse circuit detection process shown is specifically described. In Figure 4 the circuit structure of the charging module shown, the voltage sampling circuit 1 is used to obtain the voltage Vout1 of the lower output circuit, and the voltage sampling circuit 2 is used to obtain the voltage Vout2 of the upper output circuit; the voltage sampling circuit 3 is used to obtain the output terminal voltage Vout3 of the anti-reverse diode D10. When the two output circuits operate in parallel, the voltages collected by the voltage sampling circuit 1 and the voltage sampling circuit 2 can both be used as the input terminal voltage of the anti-reverse diode D10. For Figure 4 the circuit structure of the charging module shown, when detecting the anti-reverse circuit in the charging module, first, the DC / DC unit is set to the first preset state, that is, the DC / DC unit is controlled to start and the load is disconnected. Then, in the first preset state, voltage sampling is performed through the front-end voltage sampling circuit (voltage sampling circuit 1, voltage sampling circuit 2) and the back-end voltage sampling circuit (voltage sampling circuit 3) to obtain the first front-end sampling voltage (Vout1 or Vout2) and the first back-end sampling voltage (Vout3). Then, the first front-end sampling voltage (Vout1 or Vout2) and the first back-end sampling voltage (Vout3) are compared to determine whether the front and back voltages of the anti-reverse circuit are the same. If the first front-end sampling voltage (Vout1 or Vout2) and the first back-end sampling voltage (Vout3) are the same, it is determined that the anti-reverse circuit (anti-reverse diode D10) is in a good state or a short-circuit state; if the first front-end sampling voltage (Vout1 or Vout2) and the first back-end sampling voltage (Vout3) are different, it is determined that the anti-reverse circuit (anti-reverse diode D10) is in an open-circuit state.

[0078] Next, when it is determined through the first detection that the anti-reverse diode D10 is in a short-circuit state or a good state, the DC / DC unit is turned off, thereby controlling the DC / DC unit to be in a second preset state. In this state, the voltage drop rates are collected through the voltage sampling circuit 1, the voltage sampling circuit 2, and the voltage sampling circuit 3. The voltage drop rates of the voltage sampling circuit 1 and the voltage sampling circuit 2 are the sampling voltage drop rates of the front-end voltage sampling circuit, that is, the drop rates of Vout1 and Vout2, and the voltage drop rate of the voltage sampling circuit 3 is the sampling voltage drop rate of the back-end voltage sampling circuit, that is, the drop rate of Vout3. Among them, the drop rate of Vout1 is determined by the capacitance of the electrolytic capacitor C1 in the lower output circuit and its corresponding discharge circuit; the drop rate of Vout2 is mainly determined by the capacitance of the electrolytic capacitor C2 in the upper output circuit and its corresponding discharge circuit; the drop rate of Vout3 is jointly determined by the overall capacitance of the output Y capacitor and X capacitor network (i.e., the capacitor network composed of CY1, CY2, and CX1) and the output dummy load R1. Due to the blocking characteristic of the anti-reverse diode, when the anti-reverse diode D10 is in good condition, the voltage drop rates of each voltage sampling circuit are different. However, when the anti-reverse diode D10 is short-circuited, the voltage drop rates of the corresponding circuits will tend to be the same. Specifically, if the anti-reverse diode D10 fails due to a short circuit, the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1 or Vout2) will be the same as the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3); if the anti-reverse diode D10 is in good condition, due to the blocking of the anti-reverse diode D10, the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1 or Vout2) will be different from the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3). Based on this principle, the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1 or Vout2) is compared with the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3). If the drop rates are the same, it is determined that the anti-reverse diode D10 is in a short-circuit state; if the drop rates are different, it is determined that the anti-reverse diode D10 is in a good state.

[0079] For Figure 5 the charging module shown Figure 6 the anti-reverse circuit detection process shown is specifically described. In Figure 5 the circuit structure of the charging module shown, the voltage sampling circuit 1 is used to obtain the input voltage of the anti-reverse diode D9; the voltage sampling circuit 2 is used to obtain the input voltage of the anti-reverse diode D10; the voltage sampling circuit 3 is used to obtain the output voltages of the anti-reverse diode D9 and the anti-reverse diode D10. For Figure 5The circuit structure of the charging module shown. When detecting the reverse connection prevention circuit in the charging module, first, the DC / DC unit is started and the load is disconnected, and it is set to the first preset state. Then, in the first preset state, voltage sampling is performed through the front-end voltage sampling circuit (voltage sampling circuit 1, voltage sampling circuit 2) and the back-end voltage sampling circuit (voltage sampling circuit 3) to obtain the first front-end sampling voltage (Vout1 and Vout2) and the first back-end sampling voltage (Vout3). Then, the first front-end sampling voltage (Vout1 and Vout2) and the first back-end sampling voltage (Vout3) are compared to determine whether the front and back voltages of the reverse connection prevention circuit are the same. If Vout1 in the first front-end sampling voltage is the same as Vout3 in the first back-end sampling voltage, it is determined that the reverse connection prevention diode D9 is in a good state or a short-circuit state; if Vout1 in the first front-end sampling voltage is different from Vout3 in the first back-end sampling voltage, it is determined that the reverse connection prevention diode D9 is in an open-circuit state. If Vout2 in the first front-end sampling voltage is the same as Vout3 in the first back-end sampling voltage, it is determined that the reverse connection prevention diode D10 is in a good state or a short-circuit state; if Vout2 in the first front-end sampling voltage is different from Vout3 in the first back-end sampling voltage, it is determined that the reverse connection prevention diode D10 is in an open-circuit state.

[0080] Next, for the reverse connection prevention diode D9, when it is determined through the first detection that the reverse connection prevention diode D9 is in a short-circuit state or a good state, the DC / DC unit is turned off, thereby controlling the DC / DC unit to be in the second preset state. In this state, the voltage drop rates are collected through voltage sampling circuit 1 and voltage sampling circuit 3. The voltage drop rate of voltage sampling circuit 1 is the sampling voltage drop rate of the front-end voltage sampling circuit, that is, the drop rate of Vout1; the voltage drop rate of voltage sampling circuit 3 is the sampling voltage drop rate of the back-end voltage sampling circuit, that is, the drop rate of Vout3. Due to the blocking characteristics of the reverse connection prevention diode, in the case of the reverse connection prevention diode D9 being intact, the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1) is different from the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3); however, when the reverse connection prevention diode D9 is short-circuited, the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1) will tend to be consistent with the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3). Based on this principle, by comparing the sampling voltage drop rate of the front-end voltage sampling circuit (the drop rate of Vout1) and the sampling voltage drop rate of the back-end voltage sampling circuit (the drop rate of Vout3), if the drop rates are consistent, it is determined that the reverse connection prevention diode D9 is in a short-circuit state; if the drop rates are inconsistent, it is determined that the reverse connection prevention diode D9 is in a good state.

[0081] For the reverse protection diode D10, when it is determined through the first detection that the reverse protection diode D10 is in a short - circuit state or a normal state, the DC / DC unit is turned off, thereby controlling the DC / DC unit to be in a second preset state. In this state, the voltage drop rates are collected by the voltage sampling circuit 2 and the voltage sampling circuit 3. The voltage drop rate of the voltage sampling circuit 2 is the sampling voltage drop rate of the front - end voltage sampling circuit, that is, the drop rate of Vout2; the voltage drop rate of the voltage sampling circuit 3 is the sampling voltage drop rate of the back - end voltage sampling circuit, that is, the drop rate of Vout3. Due to the blocking characteristic of the reverse protection diode, when the reverse protection diode D10 is normal, the sampling voltage drop rate of the front - end voltage sampling circuit (the drop rate of Vout2) is different from the sampling voltage drop rate of the back - end voltage sampling circuit (the drop rate of Vout3); however, when the reverse protection diode D10 is short - circuited, the sampling voltage drop rate of the front - end voltage sampling circuit (the drop rate of Vout2) and the sampling voltage drop rate of the back - end voltage sampling circuit (the drop rate of Vout3) will tend to be the same. Based on this principle, by comparing the sampling voltage drop rate of the front - end voltage sampling circuit (the drop rate of Vout2) and the sampling voltage drop rate of the back - end voltage sampling circuit (the drop rate of Vout3), if the drop rates are the same, it is determined that the reverse protection diode D10 is in a short - circuit state; if the drop rates are different, it is determined that the reverse protection diode D10 is in a normal state.

[0082] Refer to Figure 7 the reverse protection circuit detection flowchart shown. This reverse protection circuit detection process can be used to detect the reverse protection circuit in Figure 4 the charging module shown. Next, the application of Figure 4 the reverse protection circuit detection process shown in Figure 7 the charging module shown will be specifically described.

[0083] Under the condition of having a load, for Figure 4Before detecting the reverse connection prevention circuit (i.e., the reverse connection prevention diode D10) in the charging module shown, the load voltage is judged to ensure safety during detection. First, control the AC / DC unit to start and control the DC / DC unit to turn off. Then, control the first relay RLY1, the second relay RLY2, and the third relay RLY3 to all open, and at this time, the two output circuits are completely isolated from the external load. Subsequently, connect the load by closing the load contactor. Assume that the maximum output voltage of these two output circuits is 1000V. Then, obtain the load voltage across the load, that is, the load battery voltage Uo3. Next, compare the load battery voltage Uo3 with the maximum output voltage of the output circuit. If the load voltage is greater than the maximum output voltage, that is, if Uo3 is greater than 1000V, then disconnect the load by opening the load contactor. Otherwise, control the first relay RLY1 and the third relay RLY3 to open, and control the second relay RLY2 to close, so that the lower output circuit and the upper output circuit are connected in series. After that, detect the reverse connection prevention circuit in the charging module.

[0084] During the detection process, first, control the AC / DC unit of the charging module to start, control the DC / DC unit to turn off and connect the load, and set it to the first preset state. In the first preset state, obtain the sampling voltage Vout1 through the voltage sampling circuit 1, obtain the sampling voltage Vout2 through the voltage sampling circuit 2, and obtain the sampling voltage Vout3 through the voltage sampling circuit 3. The sampling voltages Vout1, Vout2, and Vout3 are the first sampling voltages. Among them, the sampling voltages Vout1 and Vout2 are the first front-end sampling voltages, and the sampling voltage Vout3 is the first back-end sampling voltage. Subsequently, perform the first state detection on the reverse connection prevention circuit based on the first sampling voltages. Specifically, compare whether the first front-end sampling voltage (Vout1 or Vout2) and the first back-end sampling voltage Vout3 are consistent. If they are consistent, it is determined that the reverse connection prevention circuit (the reverse connection prevention diode D10) is in a short-circuit state; if they are not consistent, it is determined that the reverse connection prevention circuit (the reverse connection prevention diode D10) is in an open-circuit state or a good state.

[0085] When it is determined that the anti - reverse diode D10 is in an open - circuit state or a good state, disconnect the load and control the start of the DC / DC unit, so as to control the DC / DC unit to be in a second preset state. Then, in the second preset state, perform a second - stage status detection on the anti - reverse circuit to obtain the second sampling voltages of each voltage sampling circuit. Again, obtain the sampling voltage Vout1 through the voltage sampling circuit 1, obtain the sampling voltage Vout2 through the voltage sampling circuit 2, and obtain the sampling voltage Vout3 through the voltage sampling circuit 3. The sampling voltages Vout1, Vout2, and Vout3 obtained at this time are the second sampling voltages, where Vout1 and Vout2 are the second front - end sampling voltages, and Vout3 is the second back - end sampling voltage. Subsequently, perform a second - stage status detection on the anti - reverse circuit based on the second sampling voltages. As Figure 5 shown, specifically, compare whether the second front - end sampling voltage (Vout1 or Vout2) is consistent with the second back - end sampling voltage Vout3. If they are consistent, it is determined that the anti - reverse circuit (anti - reverse diode D10) is in a good state; if they are not consistent, it is determined that the anti - reverse circuit (anti - reverse diode D10) is in an open - circuit state.

[0086] Refer to Figure 8 the anti - reverse circuit detection flowchart shown. This anti - reverse circuit detection process can be used to detect the anti - reverse circuit in Figure 5 the charging module shown. The following specifically describes the application of Figure 5 the anti - reverse circuit detection process shown in Figure 8 the charging module shown.

[0087] First, start the AC / DC unit of the charging module and control the DC / DC unit to turn off and connect to the load, setting it to the first preset state. In the first preset state, obtain the sampling voltage Vout1 through the voltage sampling circuit 1, obtain the sampling voltage Vout2 through the voltage sampling circuit 2, and obtain the sampling voltage Vout3 through the voltage sampling circuit 3. The sampling voltages Vout1, Vout2, and Vout3 are the first sampling voltages. Among them, for the reverse protection diode D9, the sampling voltage Vout1 is the first front-end sampling voltage, and the sampling voltage Vout3 is the first back-end sampling voltage; for the reverse protection diode D10, the sampling voltage Vout2 is the first front-end sampling voltage, and the sampling voltage Vout3 is the first back-end sampling voltage. Subsequently, perform the first state detection on the reverse protection circuit based on the first sampling voltages. Specifically, for the reverse protection diode D9, compare whether the first front-end sampling voltage Vout1 and the first back-end sampling voltage Vout3 are consistent. If the first front-end sampling voltage Vout1 and the first back-end sampling voltage Vout3 are consistent, it is determined that the reverse protection diode D9 is in an open circuit state. If the first front-end sampling voltage Vout1 and the first back-end sampling voltage Vout3 are inconsistent, it is determined that the reverse protection diode D9 is in an open circuit state or a good state. For the reverse protection diode D10, compare whether the first front-end sampling voltage Vout2 and the first back-end sampling voltage Vout3 are consistent. If the first front-end sampling voltage Vout2 and the first back-end sampling voltage Vout3 are consistent, it is determined that the reverse protection diode D10 is in an open circuit state. If the first front-end sampling voltage Vout2 and the first back-end sampling voltage Vout3 are inconsistent, it is determined that the reverse protection diode D10 is in an open circuit state or a good state.

[0088] When it is determined that the reverse protection diode D9 is in an open circuit state or a good state, disconnect the load and control the DC / DC unit to start, thereby controlling the DC / DC unit to the second preset state. In the second preset state, perform the second state detection on the reverse protection circuit and obtain the second sampling voltages of each voltage sampling circuit. Again, obtain the sampling voltage Vout1 through the voltage sampling circuit 1 and obtain the sampling voltage Vout3 through the voltage sampling circuit 3. The sampling voltages Vout1 and Vout3 obtained at this time are the second sampling voltages. Among them, the sampling voltage Vout1 is the second front-end sampling voltage, and the sampling voltage Vout3 is the second back-end sampling voltage. Subsequently, perform the second state detection on the reverse protection circuit based on the second sampling voltages. As Figure 6 shown, specifically, compare whether the second front-end sampling voltage Vout1 and the second back-end sampling voltage Vout3 are consistent. If they are consistent, it is determined that the reverse protection diode D9 is in a good state; if they are inconsistent, it is determined that the reverse protection diode D9 is in an open circuit state.

[0089] When it is determined that the anti-reverse diode D10 is in an open-circuit state or a good state, disconnect the load and control the start of the DC / DC unit, so as to control the DC / DC unit to be in a second preset state. In the second preset state, perform a second state detection on the anti-reverse circuit to obtain the second sampling voltages of each voltage sampling circuit. Again, obtain the sampling voltage Vout2 through the voltage sampling circuit 2, and obtain the sampling voltage Vout3 through the voltage sampling circuit 3. The sampling voltages Vout2 and Vout3 obtained at this time are the second sampling voltages. Among them, the sampling voltage Vout2 is the second front-end sampling voltage, and the sampling voltage Vout3 is the second back-end sampling voltage. Subsequently, perform a second state detection on the anti-reverse circuit based on the second sampling voltages. As Figure 6 shown, specifically, compare whether the second front-end sampling voltage Vout2 is consistent with the second back-end sampling voltage Vout3. If they are consistent, it is determined that the anti-reverse diode D10 is in a good state; if they are not consistent, it is determined that the anti-reverse diode D10 is in an open-circuit state.

[0090] The second embodiment of the present application provides a charging module, and the charging module includes a controller. Among them, the controller is used to implement the charging control method of the first embodiment.

[0091] A charging system according to the third embodiment of the present application, as Figure 9 shown, the charging system includes at least two charging modules 110, at least one charging interface 120, a control center 130, and a power distribution device 140. The power distribution device 140 is respectively connected to the control center 130, each charging module 110, and each charging interface 120.

[0092] Among them, each charging module 110 is used to convert the alternating current of the power grid into direct current and provide it to each charging interface 120; the control center 130 is used to obtain the required power of each charging interface, and generate a scheduling instruction according to the connection relationship of the controllable switches in the power distribution device and each required power; the power distribution device 140 is used to control the opening or closing of the controllable switches according to the scheduling instruction, so as to distribute the output power of each charging module 110 to each charging interface.

[0093] In an optional implementation manner, the charging system provided by the embodiment of the present application is an integrated DC charging pile, and the charging interface 120 is used to connect a charging gun, and the charging gun is hung on the host of the charging system through a gun holder on the charging system main body.

[0094] In an optional implementation manner, the charging system provided by the embodiment of the present application is a split-type DC charging pile, and the charging system further includes a plurality of charging terminals. The charging interface 120 is used to connect the charging terminals, and the charging terminals are separately arranged from the charging system main body. The charging terminals are configured with single charging guns or double charging guns for outputting power to electric vehicles.

[0095] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall similarly be included in the patent protection scope of the present application.

Claims

1. A charging control method, characterized in that: For a charging module, the charging module includes a cascaded AC / DC unit and a DC / DC unit, the DC / DC unit includes a plurality of output circuits, each of the output circuits is connected to a load via a relay combination circuit, the method includes: When the AC / DC unit is started and the DC / DC unit is not started, controlling the relay combination circuit to be in a first control state so that the output circuit and the load are in an open circuit state; When the DC / DC unit is started, the relay combination circuit is controlled to be in a second control state so that the output circuits are connected in parallel or in series to meet the required voltage of the load.

2. The method according to claim 1, characterized in that The multiple output circuits include a first output circuit and a second output circuit, the relay combination circuit includes a first relay, a second relay and a third relay, the first relay is connected between the negative output terminal of the first output circuit and the negative output terminal of the second output circuit, the third relay is connected between the positive output terminal of the first output circuit and the positive output terminal of the second output circuit, and the second relay is connected between the positive output terminal of the first output circuit and the negative output terminal of the second output circuit.

3. The method according to claim 2, characterized in that The controlling the relay combination circuit to be in a first control state includes: The first relay, the second relay and the third relay are all controlled to be disconnected. Alternatively, the first relay and the third relay are controlled to be opened, and the second relay is controlled to be closed.

4. The method according to claim 2, characterized in that: The controlling the relay combination circuit to be in the second control state includes: Obtain the maximum output voltage of each output circuit; When the required voltage of the load is less than or equal to the maximum output voltage, controlling the first relay and the third relay to close, and controlling the second relay to open; When the required voltage of the load is greater than the maximum output voltage, the first relay and the third relay are controlled to be opened, and the second relay is controlled to be closed.

5. The method according to claim 1, characterized in that The multiple output circuits include a first output circuit and a second output circuit, and the relay combination circuit includes a first relay and a second relay, the first relay is connected between the negative output terminal of the first output circuit and the negative output terminal of the second output circuit, and the second relay is connected between the positive output terminal of the first output circuit and the negative output terminal of the second output circuit.

6. The method according to claim 5, characterized in that The controlling the relay combination circuit to be in a first control state includes: The first relay and the second relay are controlled to be disconnected.

7. The method according to claim 5, characterized in that The controlling the relay combination circuit to be in the second control state includes: Obtain the maximum output voltage of each output circuit; When the required voltage of the load is less than or equal to the maximum output voltage, controlling the first relay to close and controlling the second relay to open; When the required voltage of the load is greater than the maximum output voltage, the first relay is controlled to be opened, and the second relay is controlled to be closed.

8. The method according to claim 1, characterized in that The DC / DC unit further includes an anti-reverse circuit, the relay combination circuit is connected to the load via the anti-reverse circuit, and both the input and output ends of the anti-reverse circuit are provided with a voltage sampling circuit; the method further includes: Controlling the DC / DC unit to a first preset state; Performing a first state detection on the anti-reverse circuit based on the sampling voltages of each voltage sampling circuit; If the result of the first state detection fails to determine the state of the anti-reverse circuit, the DC / DC unit is controlled to a second preset state, and a second state detection is performed on the anti-reverse circuit based on the current sampling voltage of each voltage sampling circuit to determine the state of the anti-reverse circuit.

9. A charging module, characterized in that: A controller is included, and the controller is used to implement the charging control method according to any one of claims 1 to 8.

10. A charging system, characterized in that: The device comprises at least two charging modules as claimed in claim 9, at least one charging interface, a control center and a power distribution device; the power distribution device is respectively connected to the control center, each charging module and each charging interface; Wherein, each of the charging modules is used to convert the AC power of the power grid into DC power and provide it to each of the charging interfaces; The control center is used to obtain the required power of each charging interface, and generate a scheduling instruction according to the connection relationship of the controllable switches in the power distribution device and each required power; The power distribution device is used to control the opening or closing of the controllable switch according to the scheduling instruction to distribute the output power of each charging module to each charging interface.

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