Power supply control circuit and power supply system

Abstract

This application relates to a power supply control circuit and power supply system, including a relay module, a first detection module, a first timing module, and a control module. The relay module is configured with an engaged state and a reset state. The relay module is connected to a power conversion module and a power grid. In the engaged state, the relay module connects the power supply path between the power conversion module and the power grid; in the reset state, it disconnects the power supply path between the power conversion module and the power grid. The first detection module is connected to the power grid to output a first detection signal at the zero-crossing point of the power grid voltage. The first timing module is connected to the first detection module and starts timing for a first preset duration upon triggering by the first detection signal, and outputs a corresponding first timing signal. The control module is connected to both the relay module and the first timing module, receives the first timing signal, and outputs a corresponding control signal to control the relay to be in the engaged state. This application can improve the power supply security of the power supply system.

Description

Technical Field

[0001] This application relates to the field of power supply control technology, and in particular to power supply control circuits and power supply systems. Background Technology

[0002] Currently, all newly launched hybrid inverters have an off-grid load bypass mode. If the off-grid port of the hybrid inverter is connected to an impulsive load, there may be a large inrush current, which could cause the relay contacts to stick. Furthermore, random relay activation may generate a very large common-mode inrush current, accompanied by a certain amount of inrush energy, which has a certain impact on the stability of the power supply system. Utility Model Content

[0003] Therefore, it is necessary to provide a power supply control circuit and power supply system that can reduce the negative impact of common-mode impulse energy in order to address the above-mentioned technical problems.

[0004] In a first aspect, this application provides a power supply control circuit, the power supply control circuit comprising:

[0005] The relay module is configured with an engaged state and a reset state. The relay module is used to connect the power conversion module and the power grid. When the relay module is in the engaged state, it is used to conduct the power supply path between the power conversion module and the power grid. When the relay module is in the reset state, it is used to disconnect the power supply path between the power conversion module and the power grid.

[0006] A first detection module is used to connect to the power grid to output a first detection signal at the moment when the voltage of the power grid crosses zero.

[0007] A first timing module is connected to the first detection module. The first timing module starts timing for a first preset duration when triggered by the first detection signal and outputs a corresponding first timing signal.

[0008] The control module is connected to the relay module and the first timing module respectively, and is used to receive the first timing signal and output the corresponding control signal to control the relay module to be in the energized state; the first preset duration includes a first duration and a second duration; the first duration starts from the time the control module outputs the control signal and ends when the relay module receives the control signal; the second duration starts from the time the relay module receives the control signal and ends when the relay module switches to the energized state.

[0009] Secondly, this application also provides a power supply system, including a power conversion module, a power grid, and a power supply control circuit as described in the first aspect.

[0010] The aforementioned power supply control circuit and power supply system include a relay module, a first detection module, a first timing module, and a control module. The relay module is configured with an engaged state and a reset state. The relay module connects the power conversion module and the power grid. When engaged, the relay module connects the power supply path between the power conversion module and the power grid; when reset, it disconnects the power supply path. The first detection module connects to the power grid to output a first detection signal at the zero-crossing point of the grid voltage. The first timing module connects to the first detection module and, triggered by the first detection signal, starts timing for a first preset duration and outputs a corresponding first timing signal. The control module connects to both the relay module and the first timing module, receiving the first timing signal and outputting a corresponding control signal. The control signal controls the relay to be in the engaged state. Since the first preset duration includes a first duration and a second duration, the first duration begins when the control module outputs the control signal and ends when the relay module receives the control signal. The second duration begins when the relay module receives the control signal and ends when the relay module switches to the engaged state. Therefore, the control module can precisely control the relay module to switch states, achieving accurate control of the relay module. In addition, since the control module controls the relay module to engage after the first detection module detects the zero crossing of the power grid for a first preset time, it can also avoid the large impact energy caused by excessive power grid voltage to engage the relay module, thereby improving the power supply safety of the power supply system. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is one of the schematic block diagrams of the power supply control circuit in one embodiment of this application;

[0013] Figure 2 This is a schematic block diagram of the structure of a relay module in one embodiment of this application;

[0014] Figure 3 This is a schematic block diagram of the grid-connected relay module in one embodiment of this application;

[0015] Figure 4 This is a second schematic block diagram of the power supply control circuit in one embodiment of this application;

[0016] Figure 5 This is a schematic block diagram of the control module in one embodiment of this application;

[0017] Figure 6 This is the third schematic block diagram of the power supply control circuit in one embodiment of this application;

[0018] Figure 7 This is a schematic block diagram of the structure of the second detection module in one embodiment of this application;

[0019] Figure 8 This is a schematic block diagram of the structure of the first detection module in one embodiment of this application;

[0020] Figure 9 This is the fourth schematic block diagram of the power supply control circuit in one embodiment of this application.

[0021] Explanation of icon numbers:

[0022] 100: Power supply control circuit; 110: Relay module; 111: Inverter relay module; 112: Grid-connected relay module; 1121: Secondary grid-connected relay assembly; 1211#0: Secondary grid-connected neutral relay; 1211#1, 1211#2: Secondary grid-connected live relay; 1122: Primary grid-connected relay assembly; 1221#0: Primary grid-connected neutral relay; 1221#1, 1221#2: Primary grid-connected live relay; 120: First detection module; 130: First timing module; 131: First timer ; 140: Control module; 141: First comparison unit; 142: Second comparison unit; 143: Main control unit; 150: First voltage detection module; 160: Second detection module; 161: First voltage detection unit; 162: Second voltage detection unit; 163: Fifth comparison unit; 164: Sixth comparison unit; 165: Zero-crossing detection unit; 166: AND gate unit; 170: Second timing module; 180: Voltage detection module; 200: Power conversion module; 210: Three-phase inverter; 300: Power grid. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] The power supply control circuit in this application embodiment can be applied to a power supply system. The power supply system may include a power grid and a power conversion system. The power conversion system may be, for example, a PCS (Power Conversion System, energy storage converter), a hybrid inverter, etc. The power grid may be an AC power grid, and the voltage waveform of an AC power grid typically consists of a positive half-cycle and a negative half-cycle. The zero-crossing point of the power grid mentioned in this application embodiment refers to the instant when the power grid voltage waveform transitions from the positive half-cycle to the negative half-cycle or from the negative half-cycle to the positive half-cycle, i.e., the moment when the voltage value is close to zero.

[0028] See Figure 1 , Figure 1 This is one of the schematic block diagrams of a power supply control circuit 100 according to an embodiment of the present application. The power supply control circuit 100 in this embodiment includes a relay module 110, a first detection module 120, a first timing module 130, and a control module 140.

[0029] The relay module 110 is configured with an engaged state and a reset state. The relay module 110 is used to connect the power conversion module and the power grid. When the relay module 110 is in the engaged state, it is used to conduct the power supply path between the power conversion module and the power grid. When the relay module 110 is in the reset state, it is used to disconnect the power supply path between the power conversion module and the power grid.

[0030] The first detection module 120 is used to connect to the power grid to output a first detection signal at the moment when the voltage of the power grid crosses zero.

[0031] The first timing module 130 is connected to the first detection module 120. The first timing module 130 starts timing for a first preset duration when triggered by the first detection signal, and outputs the corresponding first timing signal.

[0032] The control module 140 is connected to the relay module 110 and the first timing module 130 respectively, and is used to receive the first timing signal and output the corresponding control signal to control the relay module 110 to be in the energized state; the first preset duration includes a first duration and a second duration; the first duration starts from the time the control module 140 outputs the control signal and ends when the relay module 110 receives the control signal; the second duration starts from the time the relay module 110 receives the control signal and ends when the relay module 110 switches to the energized state.

[0033] The relay module 110 may include at least one set of relays, and the set of relays may include at least one relay. For example, the set of relays may include a live wire relay and a neutral wire relay, wherein the live wire relay is used to connect to the interfaces for connecting the live wire in the power conversion module 200 and the power grid 300, respectively, and the neutral wire relay is used to connect to the interfaces for connecting the neutral wire in the power conversion module 200 and the power grid 300, respectively.

[0034] In this embodiment, the relay module 110 being in the energized state refers to all relays within the relay module 110 being in the energized state. When the relay coil is energized, a magnetic field is generated. This magnetic field attracts the armature, causing the armature to overcome the resistance of the return spring and move towards the iron core, eventually becoming tightly engaged with the iron core. This state is called the energized state. At this time, the normally open contacts of the relay module will close, and the normally closed contacts will open. In the energized state, the relay can achieve circuit conduction.

[0035] In this embodiment, the relay module 110 being in a reset state means that all relays within the relay module 110 are in a reset state. The reset state can also be called the release state. When the relay coil is de-energized, the magnetic field gradually disappears, and the armature, under the action of the return spring, leaves the iron core and returns to its initial position. This state is called the reset state. At this time, the normally open contacts of the relay return to the open state, and the normally closed contacts return to the closed state. The reset state is mainly used to interrupt circuit connections and stop signal transmission.

[0036] Depending on the type of the connected power conversion module 200, the number of relays in a set of relays can also vary. For example, the power conversion module 200 can be a three-phase converter, and correspondingly, a set of relays can include three live wire relays and one neutral wire relay.

[0037] The first detection module 120 can be any circuit or device capable of detecting the zero-crossing point of the power grid 300. For example, the first detection module 120 can be a comparator, a phase-locked loop, etc. For instance, the comparator compares the AC voltage signal of the power grid 300 with a zero level. When the AC voltage signal crosses the zero point, the output state of the comparator changes abruptly, thereby outputting a corresponding pulse signal, which is the first detection signal in this embodiment.

[0038] The first timing module 130 can be any controlled timer. The first timing module 130 is controlled by a first detection signal. Triggered by the first detection signal, the first timing module 130 begins timing. Upon completion of a first preset duration, it outputs a corresponding first timing signal. The first timing signal indicates that the first preset duration has been completed. The first timing signal can be a clock signal, a level signal, a serial communication signal, etc., and is not limited to these.

[0039] The control module 140 in this embodiment can refer to a core processor module capable of receiving instructions, processing logic, and outputting control signals. For example, the control module 140 may include an MCU (Microcontroller Unit), a CPU (Central Processing Unit), etc., but is not limited thereto.

[0040] It is understood that when the relay module 110 includes multiple relay modules, the control signals output by the control module 140 can be divided into multiple groups. Some groups of control signals are used to control a specific portion of the relay modules to switch from a reset state to an engaged state, while the remaining control signals are used to control a specific portion of the relay modules to switch from an engaged state to a reset state. In other embodiments, the control signals can also be used to control all relay modules to be in the engaged state, and are not limited to this.

[0041] In this embodiment, the first detection module 120 is connected to the power grid to output a first detection signal at the moment when the voltage of the power grid crosses zero; the first timing module 130 is connected to the first detection module 120, and starts timing for a first preset duration upon triggering the first detection signal, and outputs a corresponding first timing signal. The control module 140 is connected to the relay module 110 and the first timing module 130 respectively, and is used to receive the first timing signal and output a corresponding control signal, which is used to control the relay to be in the energized state. Since the first preset duration includes a first duration and a second duration, the first duration starts from the time the control module 140 outputs the control signal and ends when the relay module 110 receives the control signal. The second duration starts from the time the relay module 110 receives the control signal and ends when the relay module 110 switches to the energized state. Therefore, the control module 140 can control the relay module 110 to switch states in a timely manner, thereby achieving precise control of the relay module 110. In addition, since the control module 140 controls the relay module 110 to engage after the first detection module 120 detects the zero crossing of the power grid for a first preset time, it can also avoid the power grid voltage being too high, which would cause a large impact energy to the engagement of the relay module 110, thereby improving the power supply safety of the power supply system.

[0042] In one embodiment, see Appendix Figure 2 , attached Figure 2 A schematic block diagram of a relay module 110 according to an embodiment of this application is shown. The relay module 110 in this embodiment includes an inverter relay module 111 and a grid-connected relay module 112. The inverter relay module 111 is connected to the power conversion module 200 and to the control module 140. The grid-connected relay module 112 is connected to the power grid 300 and to both the inverter relay module 111 and the control module 140.

[0043] The control module 140 is used to output a control signal to the grid-connected relay module 112 upon receiving the first timing signal, so as to control the grid-connected relay module 112 to be in the energized state.

[0044] Inverter relay module 111 is located at the output terminal of power conversion module 200 and is used to control the connection between the output of power conversion module 200 and the downstream power grid 300. Inverter relay module 111 is controlled by control module 140 and can cut off the circuit to protect the circuit safety in the event of abnormal output of power conversion module 200.

[0045] The grid-connected relay module 112 is located between the inverter relay module 111 and the power grid 300. Before the power conversion module 200 is connected to the grid, it can detect the voltage, frequency, and phase of the power grid 300 to ensure that the inverter output is synchronized with the power grid 300. In the event of an abnormality in the power grid 300 (such as a power outage or abnormal voltage), it quickly disconnects the inverter from the power grid 300 to prevent damage to the inverter. When it is necessary to switch to off-grid mode, the grid-connected relay module 112 can disconnect the power conversion module 200 from the power grid 300 to ensure that the power conversion module 200 operates independently.

[0046] See appendix Figure 3 , attached Figure 3 A schematic diagram of the grid-connected relay module 112 in an embodiment of this application is shown. In some embodiments, the grid-connected relay module 112 includes a secondary grid-connected relay assembly 1121 and a primary grid-connected relay assembly 1122.

[0047] The secondary grid-connected relay assembly 1121 includes a secondary grid-connected neutral line relay 1211#0 and at least one secondary grid-connected live line relay (e.g., secondary grid-connected live line relay 1211#1 and secondary grid-connected live line relay 1211#2) connected in parallel. The secondary grid-connected neutral line relay 1211#0 and at least one secondary grid-connected live line relay (e.g., secondary grid-connected live line relay 1211#1 and secondary grid-connected live line relay 1211#2) are connected to the inverter relay module 111 and the control module 140.

[0048] The main grid-connected relay assembly 1122 includes a main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) connected in parallel. The main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) are respectively connected to the auxiliary grid-connected relay assembly 1121, and the main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) are respectively used to connect to the power grid 300.

[0049] The first timing module 130 includes multiple first timers 131. Each first timer 131 is connected to the first detection module 120 and the control module 140. The first timer 131 starts timing upon triggering by a first detection signal and outputs a corresponding first timing signal. The timing duration of each first timer 131 is respectively connected to the secondary grid-connected neutral line relay 1211#0, each secondary grid-connected live line relay (e.g., secondary grid-connected live line relay 1211#1 and secondary grid-connected live line relay 1211#2), the main grid-connected neutral line relay 1221#0, and each... The sum of the duration for the main grid-connected live wire relay (e.g., main grid-connected live wire relay 1221#1 and main grid-connected live wire relay 1221#2) to receive control signals, the duration for the secondary grid-connected neutral wire relay 1211#0, the duration for each secondary grid-connected live wire relay (e.g., secondary grid-connected live wire relay 1211#1 and secondary grid-connected live wire relay 1211#2), the duration for the main grid-connected neutral wire relay 1221#0, and the duration for each main grid-connected live wire relay (e.g., main grid-connected live wire relay 1221#1 and main grid-connected live wire relay 1221#2) to switch to the energized state corresponds to this.

[0050] The first preset durations corresponding to multiple first timers 131 can be the same or different. The first preset durations corresponding to multiple first timers 131 can be partially the same, partially different, completely different, or completely the same. The number of first timers 131 corresponds to the sum of the number of secondary grid-connected neutral line relays 1211#0, secondary grid-connected live line relays (e.g., secondary grid-connected live line relays 1211#1 and 1211#2), primary grid-connected neutral line relays 1221#0, and primary grid-connected live line relays.

[0051] For example, the secondary grid-connected relay assembly 1121 includes one secondary grid-connected neutral wire relay 1211#0 and two secondary grid-connected live wire relays (respectively, secondary grid-connected live wire relay 1211#1 and secondary grid-connected live wire relay 1211#2), the primary grid-connected relay assembly 1122 includes one primary grid-connected neutral wire relay 1221#0 and two primary grid-connected live wire relays (respectively, primary grid-connected live wire relay 1221#1 and primary grid-connected live wire relay 1221#2), and the first timing module 130 includes five first timers 131, namely, first timer 131#1, first timer 131#2, first timer 131#3, first timer 131#4 and first timer 131#5. The first timer 131#1 is connected to the first detection module 120 and the control module 140 respectively. It is triggered when the first detection signal is received, and starts timing for the first preset duration and outputs the corresponding first timing signal. The first preset duration corresponding to the first timer 131#1 is the sum of the first duration from the time the control module 140 outputs the control signal to the time the secondary grid-connected neutral line relay 1211#0 receives the control signal, and the second duration from the time the secondary grid-connected neutral line relay 1211#0 receives the control signal to the time the secondary grid-connected neutral line relay 1211#0 switches to the corresponding state (such as switching from the reset state to the energized state). For example, the first preset duration can be 6ms. The first timer 131#2 is connected to the first detection module 120 and the control module 140 respectively. It is triggered when the first detection signal is received, and starts timing for the second first preset duration and outputs the corresponding first timing signal. The first preset duration of the first timer 131#2 is the sum of the first duration from the time the control module 140 outputs the control signal until the second grid-connected live wire relay 1211#1 and the second grid-connected live wire relay 1211#2 receives the control signal, and the second duration from the time the second grid-connected live wire relay 1211#1 and the second grid-connected live wire relay 1211#2 receives the control signal until the second grid-connected live wire relay 1211#1 and the second grid-connected live wire relay 1211#2 switches to the corresponding state (such as switching from the reset state to the energized state). For example, the second first preset duration can also be 6ms. The first timer 131#3 is connected to the first detection module 120 and the control module 140 respectively. It is triggered when the first detection signal is received, and starts timing the third first preset duration and outputs the corresponding first timing signal. The first preset duration of the first timer 131#3 is the sum of the first duration from the time the control module 140 outputs the control signal to the time the main grid neutral line relay 1221#0 receives the control signal, and the second duration from the time the main grid neutral line relay 1221#0 receives the control signal to the time the main grid neutral line relay 1221#0 switches to the corresponding state (such as switching from the reset state to the energized state). For example, the third first preset duration can also be 6ms.The first timer 131#4 is connected to the first detection module 120 and the control module 140 respectively. It is triggered when the first detection signal is received, and starts timing the fourth first preset duration and outputs the corresponding first timing signal. The fourth first preset duration corresponding to the first timer 131#4 is the sum of the first duration from the time the control module 140 outputs the control signal to the time the main grid-connected live wire relay 1221#1 receives the control signal, and the second duration from the time the main grid-connected live wire relay 1221#1 receives the control signal to the time the main grid-connected live wire relay 1221#1 switches to the corresponding state (such as switching from the reset state to the energized state). For example, the fourth first preset duration can be 1 / 3 of a grid cycle. The first timer 131#5 is connected to the first detection module 120 and the control module 140 respectively. It is triggered when the first detection signal is received, and starts timing the fifth first preset duration and outputs the corresponding first timing signal. The fifth first preset duration corresponding to the first timer 131#5 is the sum of the first duration from the time the control module 140 outputs the control signal to the time the main grid-connected live wire relay 1221#2 receives the control signal, and the second duration from the time the main grid-connected live wire relay 1221#2 receives the control signal to the time the main grid-connected live wire relay 1221#2 switches to the corresponding state (such as switching from the reset state to the energized state). For example, the fifth first preset duration can be 2 / 3 of a grid cycle, but it is not limited to this.

[0052] The control module 140 includes multiple input / output interfaces, each of which is connected to a secondary grid-connected neutral relay 1211#0, a primary grid-connected neutral relay 1221#0, and at least one primary grid-connected live relay (e.g., primary grid-connected live relay 1221#1 and primary grid-connected live relay 1221#2). One of the multiple input / output interfaces is simultaneously connected to at least one secondary grid-connected live relay (e.g., secondary grid-connected live relay 1211#1 and secondary grid-connected live relay 1211#2) to output a control signal upon receiving a first timing signal, thereby controlling the corresponding secondary grid-connected neutral relay 1211#0, each secondary grid-connected live relay (e.g., secondary grid-connected live relay 1211#1 and secondary grid-connected live relay 1211#2), the primary grid-connected neutral relay 1221#0, and each primary grid-connected live relay (e.g., primary grid-connected live relay 1221#1 and primary grid-connected live relay 1221#2) to be in a energized state.

[0053] For example, the secondary grid-connected relay assembly 1121 includes one secondary grid-connected neutral relay 1211#0 and two secondary grid-connected live relays (respectively, secondary grid-connected live relay 1211#1 and secondary grid-connected live relay 1211#2), and the primary grid-connected relay assembly 1122 includes one primary grid-connected neutral relay 1221#0 and two primary grid-connected live relays (respectively, primary grid-connected live relay 1221#1 and primary grid-connected live relay 1221#2). The control module 140 may include at least five input / output interfaces, of which four input / output interfaces are respectively connected to one secondary grid-connected neutral relay 1211#0, one primary grid-connected neutral relay 1221#0 and two primary grid-connected live relays (respectively, primary grid-connected live relay 1221#1 and primary grid-connected live relay 1221#2), and the remaining input / output interface is simultaneously connected to both secondary grid-connected live relay 1211#1 and secondary grid-connected live relay 1211#2.

[0054] In this embodiment, the control module 140 is provided with multiple input / output interfaces. These interfaces are connected one-to-one with the secondary grid-connected neutral relay 1211#0, the primary grid-connected neutral relay 1221#0, and at least one primary grid-connected live relay (e.g., primary grid-connected live relay 1221#1 and primary grid-connected live relay 1221#2). Control signals are output to each relay through independent input / output interfaces, enabling independent control of each relay and preventing interference from other signals when controlling one relay, thus improving control accuracy. Furthermore, having one of the multiple input / output interfaces simultaneously connected to at least one secondary grid-connected live relay 1211 conserves input / output interface resources and avoids overuse of interface resources.

[0055] Before the relay module 110 is put into the energized state, a self-test can be performed on the relay module 110. If the relay module 110 is not damaged, putting it into the energized state ensures normal power supply to the power system. (See appendix) Figure 4 , attached Figure 4The second schematic block diagram of the power supply control circuit in one embodiment of this application is shown. In one embodiment, the power supply control circuit in this application further includes a first voltage detection module 150. The first voltage detection module 150 is connected to one end of the inverter relay module 111 connected to the power conversion module, both ends of the main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2), both ends of the auxiliary grid-connected neutral line relay 1211#0 and at least one auxiliary grid-connected live line relay (e.g., auxiliary grid-connected live line relay 1211#1 and auxiliary grid-connected live line relay 1211#2), and the control module 140, respectively, to detect the first voltage between the end of the inverter relay module 111 connected to the power conversion module and the end of the main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) connected to the power grid, and the voltage between the main grid-connected neutral line relay 1221#0 and the end of the main grid-connected live line relay 1221#2 connected to the power grid. The second voltage across the terminals of 21#0 and at least one main grid-connected live wire relay (e.g., main grid-connected live wire relay 1221#1 and main grid-connected live wire relay 1221#2) when they are in the energized state; the third voltage across the terminals of the main grid-connected neutral wire relay 1221#0 and at least one main grid-connected live wire relay (e.g., main grid-connected live wire relay 1221#1 and main grid-connected live wire relay 1221#2) when they are in the reset state; the fourth voltage across the terminals of the auxiliary grid-connected neutral wire relay 1211#0 and at least one auxiliary grid-connected live wire relay (e.g., auxiliary grid-connected live wire relay 1211#1 and auxiliary grid-connected live wire relay 1211#2) when they are in the energized state; and the fifth voltage across the terminals of the auxiliary grid-connected neutral wire relay 1211#0 and at least one auxiliary grid-connected live wire relay (e.g., auxiliary grid-connected live wire relay 1211#1 and auxiliary grid-connected live wire relay 1211#2) when they are in the reset state.

[0056] The control signals include a first signal; see appendix. Figure 4 , 5 , attached Figure 5 A schematic block diagram of the control module 140 is shown. The control module 140 includes a first comparison unit 141, a second comparison unit 142, and a main control unit 143.

[0057] The first comparison unit 141 is connected to the first voltage detection module 150 and is used to output a first comparison signal when the first voltage is greater than or equal to a preset value.

[0058] The first comparison unit 141 can be a comparator that compares a first voltage with a preset value. When a voltage is greater than or equal to the preset value, it indicates that the power conversion module has output a sinusoidal signal. At this time, it is necessary to control the relay module 110 to be in the energized state, and it also indicates that each relay needs to perform a self-test. The first comparison signal is output.

[0059] The second comparison unit 142 is connected to the first voltage detection module 150 and is used to output a second comparison signal when the difference between the second voltage and the third voltage satisfies the first difference condition.

[0060] The first difference condition can be flexibly set according to the damage detection type of at least one main grid-connected relay. For example, the damage detection types of the main grid-connected relay include stuck and unable to engage. A stuck relay means that the relay contacts cannot open normally after being closed, causing the relay to remain in a conducting state. An unable to engage relay means that the relay cannot close its contacts normally after being energized, causing the circuit to fail to conduct properly.

[0061] The explanation is based on the first difference condition used to determine whether at least one main grid-connected relay cannot be engaged. If the first difference condition is that the difference between the third voltage and the second voltage is close to 0, and both the second and third voltages are close to 0, then the main grid-connected relay has a problem with not being able to engage. The second comparison unit 142 may include two comparators and an AND gate. The two comparators compare the second voltage and the third voltage with 0, respectively. If both the second and third voltages are close to 0, they output a signal with the opposite level to the first comparison signal. If the second voltage is greater than 0 and the third voltage is equal to 0, it means there is no problem with not being able to engage. In this case, the corresponding two comparators output the corresponding comparison signals to the AND gate. The AND gate performs an AND logic operation on the corresponding two comparison signals and outputs the corresponding second comparison signal.

[0062] The following explanation uses the first difference condition to determine whether at least one main grid-connected relay is stuck. If the first difference condition is that the difference between the third voltage and the second voltage is close to 0, and both the second and third voltages are close to the grid voltage, then the main grid-connected relay is stuck. The second comparison unit 142 may include two comparators and an AND gate. The two comparators compare the second voltage and the third voltage with the grid voltage, respectively. If both the second and third voltages are close to the grid voltage, they output a signal with the opposite level to the first comparison signal. If the second voltage is less than or equal to the grid voltage, and the third voltage is equal to 0, then there is no sticking problem. The corresponding two comparators output corresponding comparison signals to the AND gate. The AND gate performs an AND logic operation on the corresponding two comparison signals and outputs the corresponding second comparison signal.

[0063] The main control unit 143 is connected to the first comparison unit 141 and the second comparison unit 142. When receiving the first comparison signal, the second comparison signal and the first timing signal, it outputs the first signal to control the main grid-connected neutral line relay 1221#0 and each of the main grid-connected live line relays (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) to be in the energized state.

[0064] The first voltage detection module 150 may include multiple sampling resistors, which are respectively connected to a corresponding relay and a first comparison unit 141 and a second comparison unit 142, for outputting a first voltage, a second voltage, a third voltage, a fourth voltage and a fifth voltage respectively.

[0065] In this embodiment, a first voltage detection module 150 is connected to the two ends of the main grid-connected neutral line relay 1221#0 and at least one main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2) to detect the voltage across the two ends of the main grid-connected neutral line relay 1221#0 and the main grid-connected live line relay (e.g., main grid-connected live line relay 1221#1 and main grid-connected live line relay 1221#2). A first comparison unit 141 detects the first voltage. If the first voltage value is greater than or equal to a preset value, it is confirmed that the power conversion module outputs a sinusoidal signal. This characterizes the requirement for the activation control of the relay module 110. At this time, the corresponding first comparison signal is output, which also indicates that each relay needs to be self-tested. If the difference between the second voltage and the third voltage meets the first difference condition, it is confirmed that each relay is normal. At this time, the main control unit 143 controls the secondary grid-connected neutral line relay 1211#0 and at least one secondary grid-connected live line relay (e.g., secondary grid-connected live line relay 1211#1 and secondary grid-connected live line relay 1211#2) to be in the activated state based on the first comparison signal, the second comparison signal and the first timing signal, confirming that the power supply circuit is safe and completing the activation control of the relay.

[0066] See appendix Figure 6 , attached Figure 6 The third schematic block diagram shows the structure of a power supply control circuit according to one embodiment of this application. In one embodiment, the power supply control circuit further includes a second detection module 160 and a second timing module 170.

[0067] The second detection module 160 is connected to both ends of the grid-connected relay module 112 and the inverter relay module 111 to output a second detection signal when the grid-connected relay module 112 is in the energized state and the voltage across the inverter relay module 111 crosses zero. The second timing module 170 is connected to the second detection module 160. Triggered by the second detection signal, the second timing module 170 times a second preset duration and outputs a corresponding second timing signal. The control module 140, upon receiving the second timing signal, outputs a control signal to the inverter relay module 111 to control the inverter relay module 111 to be in the energized state. The second preset duration includes a third duration and a fourth duration; the third duration begins when the control module 140 outputs the control signal and ends when the inverter relay module 111 receives the control signal; the fourth duration begins when the inverter relay module 111 receives the control signal and ends when the inverter relay module 111 switches to the energized state.

[0068] The second preset duration and the first preset duration can be the same or different. The second preset duration can be set according to the control delay of the control module 140 on the inverter relay module 111. For example, it can include the sum of the duration of the control module 140 outputting the corresponding control signal to the inverter relay module 111 and the duration of the inverter relay module 111 from receiving the corresponding control signal to switching to the corresponding state (e.g., from the engaged state to the reset state, or from the reset state to the engaged state).

[0069] The timing of the first detection module 120 detecting the zero-crossing point of the power grid and the second detection module 160 detecting the positive zero-crossing point of the inverter relay module 111 is not limited. For example, the first detection module 120 may first detect the zero-crossing point of the power grid, causing the control module 140 to first control the grid-connected relay module 112 to be in the energized state; then the second detection module 160 may detect the positive zero-crossing point of the inverter relay module 111, causing the control module 140 to subsequently control the inverter relay module 111 to be in the energized state. Alternatively, the second detection module 160 may first detect the positive zero-crossing point of the inverter relay module 111, causing the control module 140 to first control the inverter relay module 111 to be in the energized state; then the first detection module 120 may subsequently detect the zero-crossing point of the power grid, causing the control module 140 to subsequently control the grid-connected relay module 112 to be in the energized state.

[0070] In this embodiment, the positive zero-crossing point of the inverter relay module 111 is detected by the second detection module 160. The second timing module 170 is connected to the second detection module 160. After a second preset time after the positive zero-crossing point of the inverter relay module 111, the control module 140 outputs a control signal to the inverter relay module 111 to control the inverter relay module 111 to be in the energized state. On the one hand, by detecting the zero-crossing point of the inverter relay module 111 and controlling the inverter relay module 111 to be energized, the safety of the relay and the safety of the power supply are ensured. On the other hand, by combining the delay of the inverter relay module 111's response to the control signal and delaying the output of the control signal for a second preset time to control the inverter relay, precise control of the inverter relay can be achieved.

[0071] In some embodiments, the control module includes multiple input / output interfaces. The inverter relay module includes an inverter neutral relay and at least one inverter live relay connected in parallel. The inverter neutral relay is connected to one input / output interface of the control module, and the at least one inverter live relay is connected to the same input / output interface in the control module. The second timing module includes multiple second timers connected to the second detection module. The second timers start timing upon triggering by a second detection signal and output corresponding second timing signals. The timing duration of each second timer corresponds to the sum of the duration for which the inverter neutral relay and at least one inverter live relay receive the control signal and the duration for which the inverter neutral relay and at least one inverter live relay switch to the energized state. Upon receiving the corresponding second timing signal, the control module outputs a control signal to the corresponding inverter neutral relay and at least one inverter live relay to bring them into the energized state.

[0072] The number of second timers can correspond to the number of input / output interfaces of the control module connected to the inverter relay module. For example, taking an inverter relay module comprising one inverter neutral relay and two inverter live relays (inverter live relay #1 and inverter live relay #2) as an example, one of the two input / output interfaces of the control module is connected to the inverter neutral relay, and the other input / output interface is connected to both inverter live relay #1 and inverter live relay #2. The second timing module includes two second timers, second timer #1 and second timer #2. The first timer #1 is connected to both the second detection module and the control module, and is used to start timing for a second preset duration upon triggering by the second detection signal, so as to output a corresponding second timing signal to the control module, causing the inverter neutral relay connected to one input / output interface of the control module to be in the energized state. The second preset duration includes the sum of the time from when the control module outputs the control signal until the inverter neutral relay receives the control signal, and the time from when the inverter neutral relay receives the control signal until the inverter neutral relay switches from the reset state to the energized state. The first timer #2 is connected to both the second detection module and the control module. It is used to start timing for a second preset duration when triggered by the second detection signal, so as to output the corresponding second timing signal to the control module, causing the inverter live wire relays #1 and #2 connected to the input / output interface of the control module to be in the energized state. The second preset duration includes the sum of the duration from when the control module outputs the control signal to when the inverter live wire relays #1 and #2 receive the control signal, and the duration from when the inverter live wire relays #1 and #2 receive the control signal to when the inverter live wire relays #1 and #2 switch from the reset state to the energized state.

[0073] In this embodiment, the inverter neutral relay is connected to one input / output interface of the control module, and at least one inverter live relay is connected to the same input / output interface of the control module, so that the control module can control each inverter live relay simultaneously, saving input / output interfaces and avoiding abuse of interface resources.

[0074] In some embodiments, the first voltage detection module is also connected to both ends of the secondary grid-connected neutral relay and at least one secondary grid-connected live relay, for detecting a fourth voltage at both ends when the secondary grid-connected neutral relay and at least one secondary grid-connected live relay are in the energized state, and a fifth voltage when the secondary grid-connected neutral relay and at least one secondary grid-connected live relay are in the reset state. The power supply control circuit also includes a second voltage detection module.

[0075] The second voltage detection module is connected to both ends of the inverter neutral relay and at least one inverter live relay to detect the sixth voltage at both ends when the inverter neutral relay and at least one inverter live relay are in the energized state, and the seventh voltage at both ends when the inverter neutral relay and at least one inverter live relay are in the reset state.

[0076] The second voltage detection module may include multiple sampling resistors, which are respectively connected to the two ends of the inverter neutral line relay and at least one inverter live line relay, to detect the sixth voltage at the two ends of the inverter neutral line relay and at least one inverter live line relay when they are in the energized state, and the seventh voltage at the two ends of the inverter neutral line relay and at least one inverter live line relay when they are in the reset state.

[0077] The control signals include a second signal and a third signal; the control module also includes a third comparison unit and a fourth comparison unit.

[0078] The third comparison unit is connected to the first voltage detection module and outputs a third comparison signal when the difference between the fourth voltage and the fifth voltage meets the second difference condition. The main control unit is also used to output a second signal when receiving the second comparison signal and the first timing signal, so as to control the secondary grid-connected neutral line relay and at least one secondary grid-connected live line relay to be in the energized state.

[0079] The third comparison unit determines whether the difference between the fourth and fifth voltages meets the second difference condition, enabling self-testing of the secondary grid-connected neutral relay. Similar to the first difference condition, the second difference condition can also be based on the abnormality detection type of the secondary grid-connected neutral relay, which may include being stuck or unable to engage.

[0080] The fourth comparison unit is connected to the first voltage detection module, the inverter neutral relay, and at least one inverter live relay. When the difference between the sixth and seventh voltages satisfies the third difference condition, it outputs a fourth comparison signal. Upon receiving the fourth comparison signal and the second timing signal, the main control unit outputs a third signal to correspondingly control the inverter neutral relay and at least one inverter live relay to be in the energized state.

[0081] The fourth comparison unit determines whether the difference between the sixth and seventh voltages meets the third difference condition, enabling self-testing of the secondary grid-connected live wire relay. Similar to the first and second difference conditions, the third difference condition can also be based on the abnormality detection type of the secondary grid-connected live wire relay, which may include being stuck or unable to engage.

[0082] Upon receiving the third and fourth comparison signals, the main control unit confirms that there are no abnormalities in the secondary grid-connected neutral relay, at least one secondary grid-connected live relay, the inverter neutral relay, and at least one inverter live relay. After a first preset time, the main control unit controls the secondary grid-connected neutral relay and at least one secondary grid-connected live relay to be in the energized state. After a second preset time, the main control unit controls the inverter neutral relay and at least one inverter live relay to be in the energized state, thereby achieving precise control over the secondary grid-connected neutral relay, at least one secondary grid-connected live relay, the inverter neutral relay, and at least one inverter live relay.

[0083] See appendix Figure 7 , attached Figure 7 A schematic block diagram of the structure of the second detection module 160 in an embodiment of this application is shown. The second detection module 160 in this embodiment includes a first voltage detection unit 161, a second voltage detection unit 162, a fifth comparison unit 163, a sixth comparison unit 164, a zero-crossing detection unit 165, and an AND gate unit 166.

[0084] The first voltage detection unit 161 is connected to one end of the grid-connected relay module 112 and outputs a first voltage signal. The second voltage detection unit 162 is connected to the other end of the grid-connected relay module 112 and outputs a second voltage signal. The fifth comparison unit 163 is connected to the first voltage detection unit 161 and outputs a third comparison signal when the voltage value of the first voltage signal is greater than or equal to a preset positive value. The sixth comparison unit 164 is connected to the second voltage detection unit 162 and outputs a fourth comparison signal when the voltage value of the second voltage signal is greater than or equal to a preset positive value. The zero-crossing detection unit 165 is connected to the inverter relay module 111 and outputs a fifth signal when the voltage of the inverter relay module 111 crosses zero. The AND gate unit 166 is connected to the fifth comparison unit 163, the sixth comparison unit 164, the zero-crossing detection unit 165, and the second timing module 170, respectively, to output a second detection signal when the third, fourth, and fifth comparison signals are received.

[0085] In this embodiment, the voltage across the grid-connected relay module 112 is detected by the first voltage detection unit 161 and the second voltage detection unit 162, respectively. The fifth comparison unit 163 and the sixth comparison unit 164 compare the first voltage signal and the second voltage signal with preset positive values, respectively. The fifth comparison unit 163 outputs a third comparison signal when the voltage value of the first voltage signal is greater than or equal to the preset value, and the sixth comparison unit 164 outputs a fourth comparison signal when the voltage value of the second voltage signal is greater than or equal to the preset value. At this time, it is confirmed that the grid-connected relay module 112 is in the energized state. The zero-crossing detection unit 165 detects the time when the voltage of the inverter relay module 111 crosses zero and outputs the corresponding fifth signal. When the AND gate unit 166 receives the third comparison signal, the fourth comparison signal and the fifth signal at the same time, it outputs a second detection signal.

[0086] See appendix Figure 8 , attached Figure 8 A schematic block diagram of the structure of the first detection module 120 in an embodiment of this application is shown. In one embodiment, the first detection module 120 in this application may include a first comparator U1, a first resistor R1, a second resistor R2, and a first capacitor C1.

[0087] The inverting input of the first comparator U1 is connected to the power grid 300, and the output of the first comparator U1 is connected to the first timing module 130130. The first resistor R1 is connected to both the non-inverting input and output of the first comparator U1. The first end of the second resistor R2 is connected to the non-inverting input of the first comparator U1, and the second end of the second resistor R2 is used to connect to a preset voltage Vref. The first end of the first capacitor C1 is connected to the non-inverting input of the first comparator U1, and the second end of the first capacitor C1 is used to connect to the preset voltage Vref.

[0088] In this embodiment, the inverting input of the first comparator U1 is connected to the power grid 300 to receive the voltage from the power grid 300. The non-inverting input of the first comparator U1 is connected to the output of the first comparator U1 via the first resistor R1, forming a feedback loop to stabilize the comparator's output. The first terminal of the first capacitor C1 is connected to the non-inverting input of the first comparator U1, and the second terminal of the first capacitor C1 is used to connect to a preset voltage Vref, which can be understood as a reference voltage. The first capacitor C1 provides a filtering function to ensure the stability of the input signal.

[0089] In one embodiment, see Appendix Figure 4 and attached Figure 9 , attached Figure 9The fourth schematic block diagram of the power supply control circuit 100 according to one embodiment of this application is shown. The power supply control circuit 100 in this embodiment includes a relay module 110, a control module 140, a first detection module 120, and a voltage detection module 180. The relay module 110 includes an inverter relay module 111, a secondary grid-connected relay module 112, and a primary grid-connected relay module 112. The inverter relay module 111 includes a first live wire inverter relay R11, a second live wire inverter relay R12, a third live wire inverter relay R13, and a neutral wire inverter relay L1. The secondary grid-connected relay module 112 includes a first secondary grid-connected inverter relay R21, a second secondary grid-connected inverter relay R22, a third secondary grid-connected inverter relay R23, and a secondary grid-connected inverter relay L2. The primary grid-connected relay module 112 includes a first primary grid-connected inverter relay R31, a second primary grid-connected inverter relay R32, a third primary grid-connected inverter relay R33, and a primary grid-connected inverter relay L3. The first live-wire inverter relay R11 is connected to the three-phase inverter 210 and the first auxiliary grid-connected inverter relay R21. The second live-wire inverter relay R12 is connected to the three-phase inverter 210 and the second auxiliary grid-connected inverter relay R22. The third live-wire inverter relay R13 is connected to the three-phase inverter 210 and the third auxiliary grid-connected inverter relay R23. The neutral-wire inverter relay L1 is connected to the three-phase inverter 210 and the auxiliary grid-connected inverter relay L2. The first auxiliary grid-connected inverter relay R21 is also connected to the first main grid-connected inverter relay R31. The second auxiliary grid-connected inverter relay R22 is also connected to the second main grid-connected inverter relay R32. The third auxiliary grid-connected inverter relay R23 is also connected to the third main grid-connected inverter relay R33. The auxiliary grid-connected inverter relay L2 is also connected to the main grid-connected inverter relay L3. The first main grid-connected inverter relay R31, the second main grid-connected inverter relay R32, the third main grid-connected inverter relay R33, and the main grid-connected inverter relay L3 are also connected to the power grid 300.

[0090] The control module 140 is connected to each relay to control the activation or deactivation of each relay. Specifically, the control module 140 is connected to the first live wire inverter relay R11, the second live wire inverter relay R12, and the third live wire inverter relay R13 via an input / output interface to simultaneously control their activation or deactivation. The control module 140 also controls the activation or deactivation of the neutral wire inverter relay L1 via an input / output interface. Furthermore, the control module 140 is connected to the first auxiliary grid-connected inverter relay R21, the second auxiliary grid-connected inverter relay R22, and the third auxiliary grid-connected inverter relay R23 via an input / output interface to simultaneously control their activation or deactivation. Finally, the control module 140 controls the activation or deactivation of the auxiliary grid-connected inverter relay L2 via an input / output interface. The control module 140 connects to the first main grid-connected inverter relay R31, the second main grid-connected inverter relay R32, the third main grid-connected inverter relay R33, and the main grid-connected inverter relay L3 through four input / output interfaces, respectively, to independently control the activation or deactivation of the main grid-connected inverter relays R31, R32, R33, and L3.

[0091] The voltage detection module 180 is connected to the two ends of the first live wire inverter relay R11, the second live wire inverter relay R12, the third live wire inverter relay R13, the neutral wire inverter relay L1, the first auxiliary grid-connected inverter relay R21, the second auxiliary grid-connected inverter relay R22, the third auxiliary grid-connected inverter relay R23, the auxiliary grid-connected inverter relay L2, the first main grid-connected inverter relay R31, the second main grid-connected inverter relay R32, the third main grid-connected inverter relay R33, and the main grid-connected inverter relay L3, respectively. It is used to acquire the voltage across each relay, enabling the control module 140 to perform a self-test on each relay based on the voltage across each relay. Upon successful self-testing, the module controls each relay to engage. The self-testing process and the process of controlling the engagement of each relay can be found in the previous embodiments and will not be repeated here.

[0092] In one embodiment, a power supply system is also provided. The power supply system in this embodiment may include a power conversion module, a power grid, and a power supply control circuit as described in any of the above embodiments.

[0093] In this embodiment, the power supply system includes the power supply control circuit in any of the above embodiments. If the power supply control circuit has further beneficial effects, the power supply system will also have further beneficial effects accordingly.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the appended claims.

Claims

1. A power supply control circuit, characterized by comprising: The power supply control circuit includes: The relay module is configured with an engaged state and a reset state. The relay module is used to connect the power conversion module and the power grid. When the relay module is in the engaged state, it is used to conduct the power supply path between the power conversion module and the power grid. When the relay module is in the reset state, it is used to disconnect the power supply path between the power conversion module and the power grid. A first detection module is used to connect to the power grid to output a first detection signal at the moment when the voltage of the power grid crosses zero. A first timing module is connected to the first detection module. The first timing module starts timing for a first preset duration when triggered by the first detection signal and outputs a corresponding first timing signal. The control module is connected to the relay module and the first timing module respectively, and is used to receive the first timing signal and output the corresponding control signal to control the relay module to be in the energized state; the first preset duration includes a first duration and a second duration; the first duration starts from the time the control module outputs the control signal and ends when the relay module receives the control signal; the second duration starts from the time the relay module receives the control signal and ends when the relay module switches to the energized state.

2. The power supply control circuit according to claim 1, characterized in that, The relay module includes: An inverter relay module is used to connect to the power conversion module and to the control module; A grid-connected relay module is used to connect to the power grid and is connected to the inverter relay module and the control module; Upon receiving the first timing signal, the control module outputs a control signal to the grid-connected relay module to control the grid-connected relay module to be in an engaged state.

3. The power supply control circuit according to claim 2, characterized in that, The grid-connected relay module includes: A secondary grid-connected relay assembly includes a secondary grid-connected neutral line relay and at least one secondary grid-connected live line relay connected in parallel, wherein the secondary grid-connected neutral line relay and at least one of the secondary grid-connected live line relays are connected to the inverter relay module and the control module. The main grid-connected relay assembly includes a main grid-connected neutral line relay and at least one main grid-connected live line relay connected in parallel. The main grid-connected neutral line relay and at least one main grid-connected live line relay are respectively connected to the auxiliary grid-connected relay, and the main grid-connected neutral line relay and at least one main grid-connected live line relay are respectively used to connect to the power grid. The first timing module includes multiple first timers, each of which is connected to the first detection module and the control module. The first timer starts timing upon being triggered by the first detection signal and outputs a corresponding first timing signal. The timing duration of each first timer corresponds to the sum of the duration for which the auxiliary grid-connected neutral line relay, each auxiliary grid-connected live line relay, the main grid-connected neutral line relay, and each main grid-connected live line relay receive the control signal, and the duration for which the auxiliary grid-connected neutral line relay, each auxiliary grid-connected live line relay, the main grid-connected neutral line relay, and each main grid-connected live line relay switch to the engaged state. The control module includes multiple input / output interfaces, each of which is connected to the secondary grid-connected neutral relay, the primary grid-connected neutral relay, and at least one primary grid-connected live relay. One of the multiple input / output interfaces is simultaneously connected to at least one secondary grid-connected live relay to output the control signal upon receiving the first timing signal, thereby controlling the corresponding secondary grid-connected neutral relay, each of the secondary grid-connected live relays, the primary grid-connected neutral relay, and each of the primary grid-connected live relays to be in a energized state.

4. The power supply control circuit according to claim 3, characterized in that, The power supply control circuit also includes: A first voltage detection module is connected to one end of the power conversion module of the inverter relay module, both ends of the main grid-connected neutral line relay and at least one main grid-connected live line relay, and the control module, respectively, to detect the first voltage between the end of the inverter relay module connected to the power conversion module and the end of the main grid-connected neutral line relay and at least one main grid-connected live line relay connected to the power grid, the second voltage between the two ends of the main grid-connected neutral line relay and at least one main grid-connected live line relay when they are in the energized state, and the third voltage between the two ends of the main grid-connected neutral line relay and at least one main grid-connected live line relay when they are in the reset state; The control signal includes a first signal; the control module includes: The first comparison unit is connected to the first voltage detection module and is used to output a first comparison signal when the first voltage is greater than or equal to a preset value. The second comparison unit is connected to the first voltage detection module and is used to output a second comparison signal when the difference between the second voltage and the third voltage satisfies the first difference condition. The main control unit is connected to the second comparison unit and the first comparison unit. When it receives the first comparison signal, the second comparison signal and the first timing signal, it outputs the first signal to control the main grid-connected neutral line relay and each of the main grid-connected live line relays to be in the energized state.

5. The power supply control circuit according to claim 4, characterized in that, Also includes: The second detection module is connected to both ends of the grid-connected relay module and both ends of the inverter relay module, so as to output a second detection signal when the grid-connected relay module is in the energized state and the voltage across the inverter relay module is detected to be zero. The second timing module is connected to the second detection module and the control module. The second timing module times a second preset duration when triggered by the second detection signal and outputs a corresponding second timing signal. The second preset duration includes a third duration and a fourth duration. The third duration starts from the time the control module outputs the control signal and ends when the inverter relay module receives the control signal. The fourth duration starts from the time the inverter relay module receives the control signal and ends when the inverter relay module switches to the energized state. The control module is also configured to output the control signal to the inverter relay module upon receiving the second timing signal, so as to control the inverter relay module to be in the energized state.

6. The power supply control circuit according to claim 5, characterized in that, The control module includes multiple input / output interfaces; The inverter relay module includes an inverter neutral line relay and at least one inverter live line relay connected in parallel. The inverter neutral line relay is connected to one of the input / output interfaces of the control module, and at least one of the inverter live line relays is connected to the same input / output interface in the control module. The second timing module includes multiple second timers, which are connected to the second detection module. The second timers start timing when triggered by the second detection signal and output the corresponding second timing signal. The timing duration of each of the second timers corresponds to the sum of the duration during which the inverter neutral line relay and at least one inverter live line relay receive the control signal and the duration during which the inverter neutral line relay and at least one inverter live line relay switch to the engaged state. Upon receiving the corresponding second timing signal, the control module outputs the control signal to the corresponding inverter neutral relay and at least one inverter live relay, so that the inverter neutral relay and at least one inverter live relay are in the energized state.

7. The power supply control circuit according to claim 6, characterized in that, The first voltage detection module is also connected to both ends of the secondary grid-connected neutral relay and at least one of the secondary grid-connected live relays, and is used to detect the fourth voltage at both ends when the secondary grid-connected neutral relay and at least one of the secondary grid-connected live relays are in the energized state, and the fifth voltage when the secondary grid-connected neutral relay and at least one of the secondary grid-connected live relays are in the reset state. The power supply control circuit also includes: The second voltage detection module is connected to both ends of the inverter neutral line relay and at least one inverter live line relay to detect the sixth voltage at both ends when the inverter neutral line relay and at least one inverter live line relay are in the energized state, and the seventh voltage at both ends when the inverter neutral line relay and at least one inverter live line relay are in the reset state. The control signal includes a second signal and a third signal; the control module further includes: The third comparison unit is connected to the first voltage detection module and outputs a third comparison signal when the difference between the fourth voltage and the fifth voltage satisfies the second difference condition. The main control unit is also used to output the second signal when receiving the third comparison signal and the first timing signal, so as to control the auxiliary grid-connected neutral line relay and at least one of the auxiliary grid-connected live line relays to be in the energized state. The fourth comparison unit is connected to the first voltage detection module, the inverter neutral line relay and at least one of the inverter live line relays, and outputs a fourth comparison signal when the difference between the sixth voltage and the seventh voltage satisfies the third difference condition. The main control unit outputs the third signal upon receiving the fourth comparison signal and the second timing signal, thereby controlling the inverter neutral relay and at least one inverter live relay to be in the energized state.

8. The power supply control circuit according to claim 5, characterized in that, The second detection module includes: The first voltage detection unit is connected to one end of the grid-connected relay module and outputs a first voltage signal; The second voltage detection unit is connected to the other end of the grid-connected relay module and outputs a second voltage signal; The fifth comparison unit is connected to the first voltage detection unit and outputs a third comparison signal when the voltage value of the first voltage signal is greater than or equal to a preset positive value. The sixth comparison unit is connected to the second voltage detection unit and outputs a fourth comparison signal when the voltage value of the second voltage signal is greater than or equal to the preset positive value. The zero-crossing detection unit is connected to the inverter relay module and outputs a fifth signal when the voltage of the inverter relay module crosses zero. An AND gate unit is connected to the fifth comparison unit, the sixth comparison unit, the zero-crossing detection unit, and the second timing module, respectively, to output the second detection signal upon receiving the third comparison signal, the fourth comparison signal, and the fifth signal.

9. The power supply control circuit according to claim 1, characterized in that, The first detection module includes: A first comparator, the inverting input of the first comparator is connected to the power grid, and the output of the first comparator is connected to the first timing module; The first resistor is connected to the non-inverting input terminal and the output terminal of the first comparator, respectively. The second resistor has its first end connected to the non-inverting input of the first comparator, and its second end is used to connect a preset voltage. The first capacitor has its first terminal connected to the non-inverting input of the first comparator, and its second terminal is used to connect to a preset voltage.

10. A power supply system, characterized in that, It includes a power conversion module, a power grid, and a power supply control circuit as described in any one of claims 1 to 9.

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