Distribution box and power supply system

Abstract

The utility model discloses a power distribution box and a power supply system. The power distribution box comprises a power converter, a change-over switch and a power distribution box body, a first movable contact of the change-over switch is connected with a grid-connected port of the power converter, and the first movable contact of the change-over switch is also used for being connected with a power grid; a second movable contact of the change-over switch is connected with an off-network port of the power converter; the static contact of the change-over switch is connected with the first end of the distribution box, and the second end of the distribution box is connected with a load. According to the technical scheme, the connection between the power converter and the distribution box can be realized on the premise of not damaging the building structure.

Description

Technical Field

[0001] This application relates to the field of power supply technology, specifically to a distribution box and power supply system. Background Technology

[0002] With the increasing popularity of new energy sources, the application of residential new energy power supply systems is becoming more and more common. In traditional power supply systems, the power converter needs to be connected to the distribution box using two wires: a grid-connected wire and an off-grid wire.

[0003] Since the power converter is installed outside the house, it can cause some damage to the house when using two wires, one connected to the grid and one off-grid, to connect to the distribution box inside the house. Utility Model Content

[0004] In view of this, embodiments of this application provide a distribution box and power supply system that can connect the power converter to the distribution box without damaging the building structure.

[0005] This application provides a power supply system, including: a power converter, a switching switch, and a distribution box; the first moving contact of the switching switch is connected to the grid-connected port of the power converter, and the first moving contact of the switching switch is also used to connect to the power grid; the second moving contact of the switching switch is connected to the off-grid port of the power converter; the stationary contact of the switching switch is connected to the first end of the distribution box, and the second end of the distribution box is used to connect to the load.

[0006] One possible implementation is that the distribution box includes a switching circuit; the stationary contact of the changeover switch is connected to the first terminal of the switching circuit, which is used to connect a first type of load; the second terminal of the switching circuit is used to connect a second type of load; the power supply priority of the first type of load is higher than that of the second type of load; the switching circuit is used to disconnect when the power grid fails.

[0007] One possible implementation is that the switching circuit includes a voltage sampling circuit, a processing circuit, and an execution switch. The input terminal of the voltage sampling circuit is connected to the first terminal of the switching circuit and is configured to sample the voltage at the first terminal of the switching circuit. The sampled voltage is rectified and divided to obtain a voltage after voltage division. The input terminal of the processing circuit is connected to the output terminal of the voltage sampling circuit, and the output terminal of the processing circuit is connected to the execution switch. The processing circuit is configured to compare the voltage after voltage division with a voltage threshold to obtain a comparison result. The comparison result is used to control the execution switch to open or close.

[0008] One possible implementation includes a processing circuit comprising: a first comparator, a second comparator, and a flip-flop; the negative input of the first comparator is connected to the output of a voltage sampling circuit, the positive input of the first comparator is connected to a first voltage threshold, and the output of the first comparator is connected to the reset terminal of the flip-flop; the output of the flip-flop is connected to an execution switch; the positive input of the second comparator is connected to the output of the voltage sampling circuit, the negative input of the second comparator is connected to a second voltage threshold, and the output of the second comparator is connected to the input of the flip-flop; wherein the first voltage threshold is less than the second voltage threshold.

[0009] One possible implementation is a falling-edge trigger.

[0010] In one possible implementation, the switching circuit further includes: a control circuit; the input terminal of the control circuit is connected to the output terminal of the processing circuit; the output terminal of the control circuit is connected to an execution switch; the execution switch is a contactor; the control circuit includes a relay, which is connected in series in the power supply circuit of the contactor.

[0011] One possible implementation is that the voltage sampling circuit includes a rectifier circuit, a filter circuit, and a voltage divider circuit; the input terminal of the rectifier circuit is connected to the first terminal of the switching circuit, the output terminal of the rectifier circuit is connected to the input terminal of the filter circuit, the output terminal of the filter circuit is connected to the input terminal of the voltage divider circuit, and the output terminal of the voltage divider circuit is connected to the input terminal of the processing circuit.

[0012] In one possible implementation, the distribution box further includes: a main switch, a first branch switch, and a second branch switch; the first end of the main switch is connected to the stationary contact of the switching switch, and the second end of the main switch is connected to the first end of the switching circuit; the second end of the switching circuit is connected to a second type of load through the first branch switch, and the second end of the main switch is connected to a first type of load through the second branch switch.

[0013] One possible implementation is that the DC side of the power converter is used to connect to at least one of a battery or a photovoltaic module.

[0014] This application embodiment also provides a distribution box, including: a switching circuit; a first end of the switching circuit is connected to the stationary contact of a changeover switch, and a second end of the switching circuit is used to connect a second type of load; wherein, a first moving contact of the changeover switch is connected to the grid-connected port of a power converter, and the first moving contact of the changeover switch is also used to connect to the power grid, and a second moving contact of the changeover switch is connected to the off-grid port of the power converter; the first end of the switching circuit is used to connect a first type of load; wherein, the power supply priority of the first type of load is higher than that of the second type of load; the switching circuit is used to disconnect when the power grid fails.

[0015] In one possible implementation, the switching circuit includes a voltage sampling circuit, a processing circuit, and an execution switch. The input terminal of the voltage sampling circuit is connected to the first terminal of the switching circuit and is configured to sample the voltage at the first terminal of the switching circuit. The sampled voltage is rectified and divided to obtain a voltage after voltage division. The input terminal of the processing circuit is connected to the output terminal of the voltage sampling circuit, and the output terminal of the processing circuit is connected to the execution switch. The processing circuit is configured to compare the voltage after voltage division with a voltage threshold to obtain a comparison result. The comparison result is used to drive the execution switch to open or close.

[0016] In one possible implementation, the switching circuit further includes: a control circuit; the input of the control circuit is connected to the output of the processing circuit, and the output of the control circuit is connected to the execution switch; the processing circuit sends the comparison result to the control circuit; the control circuit is configured to drive the execution switch to open or close according to the comparison result.

[0017] One possible implementation includes a processing circuit comprising: a first comparator, a second comparator, and a flip-flop; the negative input of the first comparator is connected to the output of a voltage sampling circuit, the positive input of the first comparator is connected to a first voltage threshold, and the output of the first comparator is connected to the reset terminal of the flip-flop; the positive input of the second comparator is connected to the output of the voltage sampling circuit, the negative input of the second comparator is connected to a second voltage threshold, and the output of the second comparator is connected to the input of the flip-flop; wherein the first voltage threshold is less than the second voltage threshold.

[0018] The power supply system provided in this application embodiment utilizes an existing wire connected to the power grid in the distribution box to avoid damaging the building structure. A switching switch is installed outside the building. The first moving contact of the switching switch is connected to the grid-connected port of the power converter and a portion of the existing wire is connected to the power grid. The second moving contact of the switching switch is connected to the off-grid port of the power converter. The stationary contact of the switching switch is connected to the distribution box using another portion of the existing wire. By operating the switching switch, the source of power can be selected to supply power to the load. This eliminates the need to install two additional wires to connect the grid-connected and off-grid ports of the power converter to the distribution box, thus avoiding damage to the building structure and ensuring that the load is continuously powered. Attached Figure Description

[0019] Figure 1A A schematic diagram of a power supply system provided in an embodiment of this application;

[0020] Figure 1B A schematic diagram of yet another power supply system provided in the embodiments of this application;

[0021] Figure 2A A schematic diagram of a switching circuit provided in an embodiment of this application;

[0022] Figure 2BA schematic diagram of another switching circuit provided in an embodiment of this application;

[0023] Figure 3 A schematic diagram of yet another switching circuit provided in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of another power supply system provided in an embodiment of this application. Detailed Implementation

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0026] See Figure 1A This figure is a schematic diagram of a power supply system provided in an embodiment of this application.

[0027] The power supply system provided in this application embodiment includes: a power converter 100, a switching switch S1, and a distribution box 200.

[0028] The DC side of the power converter 100 can be connected to at least one of photovoltaic (PV) modules or batteries. For example, if the power converter 100 includes an energy storage converter, the power converter 100 can convert the DC power from at least one of the batteries and photovoltaic modules (PV) into AC power, and supply power to the load through a grid-connected port or an off-grid port; or, it can convert the AC power from the grid into DC power through the grid-connected port to charge the batteries.

[0029] The first moving contact A of the switching switch S1 is connected to the grid connection port of the power converter 100, and is also used to connect to the power grid; the second moving contact B of the switching switch S1 is connected to the off-grid port of the power converter 100; the stationary contact C of the switching switch S1 is connected to the first terminal of the distribution box 200, and the second terminal of the distribution box 200 is used to connect to the load. This application embodiment does not specifically limit the type of load, but includes at least important loads, so that the power converter can continue to supply power to the load when the power grid is interrupted.

[0030] One possible implementation, see Figure 1B The distribution box 200 may also include a switching circuit 101. The corresponding loads may include Class I loads and Class II loads.

[0031] The stationary contact C of the switching switch S1 is connected to the first terminal of the switching circuit 101, and the second terminal of the switching circuit 101 is connected to the second type of load.

[0032] The first terminal of the switching circuit 101 is connected to a first-class load; the power supply priority of the first-class load is higher than that of the second-class load. Among them, the first-class load is the important load, and the second-class load is the regular load.

[0033] Switching circuit 101 is used to disconnect when the power grid fails. Specifically, when the power grid fails, the stationary contact C of the switching switch S1 connects to the second moving contact B. At this time, the off-grid port of the power converter 100 supplies power to the distribution box 200, and switching circuit 101 in the distribution box 200 disconnects, so the second type of load has no power supply. The first type of load is powered by the off-grid port of the power converter 100.

[0034] The power supply system provided in this application embodiment utilizes an existing wire in the distribution box to avoid damaging the building structure. This wire can be connected to an external switch, which is a selector switch that allows users to choose the power source as needed. When the distribution box draws power from the grid, the switch connects to the grid. When the grid loses power, the switch connects to a power converter, which then connects to the distribution box to supply power to the load. Therefore, the distribution box does not need two additional wires to connect to the power converter, thus avoiding any damage to the building structure and ensuring a continuous power supply to the load. This power supply system achieves both connection between the distribution box and the power converter, and connection between the distribution box and the grid, without compromising the building structure.

[0035] This application does not specifically limit the scenario of the power supply system. It can be for household electricity or factory electricity. The voltage output on the AC side of the power converter 100 can be single-phase AC or three-phase AC.

[0036] The following describes one implementation of the switch circuit 101 with reference to the attached diagram.

[0037] See Figure 2A The figure is a schematic diagram of a switching circuit 101 provided in an embodiment of this application.

[0038] The power supply system provided in this application embodiment includes a switching circuit 101 comprising a voltage sampling circuit 10, a processing circuit 20, a control circuit 30, and an execution switch 40.

[0039] The input terminal of the voltage sampling circuit 10 is connected to the first terminal of the switching circuit 101, and the output terminal of the voltage sampling circuit 10 is connected to the input terminal of the processing circuit 20. The voltage sampling circuit 10 is used to sample the voltage at the first terminal of the switching circuit 101, and to rectify and divide the sampled voltage to obtain the divided voltage, and then send the divided voltage to the processing circuit 20.

[0040] Since the first input of the switching circuit 101 is AC power, it needs to be rectified into DC power for subsequent processing. Furthermore, since the processing circuit 20 is an analog circuit, the processed voltage cannot be too high; the rectified DC voltage needs to be divided to reduce it to a lower voltage for subsequent processing.

[0041] The output terminal of the processing circuit 20 is connected to the input terminal of the control circuit 30. The processing circuit 20 is used to compare the voltage after voltage division with the voltage threshold, obtain the comparison result, and send the comparison result to the control circuit 30.

[0042] The processing circuit 20 compares the voltage after voltage division with the voltage threshold to determine whether the grid voltage has dropped. When the grid voltage drops, it determines that the power converter 100 is operating in an off-grid state.

[0043] The output of the control circuit 30 is connected to the execution switch 40. The control circuit 30 is used to drive the execution switch 40 to open or close according to the comparison result.

[0044] When the processing circuit 20 determines that the power grid has lost power and the power converter 100 is operating in an off-grid state, the control circuit 30 controls the execution switch 40 to open, and the distribution box 200 supplies power only to important loads.

[0045] In some embodiments, the actuator switch 40 is a contactor. Since the voltage in the circuit connected to the contactor is relatively high, the general processing circuit 20 cannot directly drive the contactor to operate. Therefore, a control circuit 30 is required. The control circuit 30 may include a relay, which acts as an intermediate device to drive the contactor's operation. For example, the relay can be connected in series in the contactor's power supply circuit. When the relay coil is energized, the relay contacts connected in series in the contactor's power supply circuit close, thus connecting the contactor's power supply circuit and enabling the contactor to operate.

[0046] It should be understood that when the switching device is a controllable switching transistor, such as a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) or an Insulated-Gate Bipolar Transistor (IGBT), the switching circuit may not include a control circuit. See also Figure 2B This figure is a schematic diagram of another switching circuit provided in an embodiment of this application.

[0047] The switching circuit includes a voltage sampling circuit 10, a processing circuit 20, and an execution switch 40. Its working principle is similar to... Figure 2A The difference is that the output of the processing circuit 20 is directly connected to the control terminal of the execution switch 40. The comparison result output by the processing circuit 20 directly drives the execution switch 40 to operate, without the need for a first-level control circuit.

[0048] The following section, with reference to the accompanying diagram, describes a specific implementation method for a switching circuit.

[0049] See Figure 3 This figure is a schematic diagram of another switching circuit provided in an embodiment of this application.

[0050] In the power supply system provided in this application embodiment, the voltage sampling circuit includes a rectifier circuit 11, a filter circuit, and a voltage divider circuit; the filter circuit includes a capacitor C as an example, and the voltage divider circuit includes a first resistor R1 and a second resistor R2 as an example.

[0051] The input terminal of rectifier circuit 11 is connected to the first terminal of the switching circuit, and the output terminal of rectifier circuit 11 is connected to the input terminal of the filter circuit, i.e., capacitor C is connected between the positive and negative output terminals of rectifier circuit 11. The output voltage of rectifier circuit 11 is represented by V1. The output terminal of filter circuit 11 is connected to the input terminal of voltage divider circuit, and the output terminal of voltage divider circuit is connected to the input terminal of processing circuit.

[0052] The first end of the first resistor R1 is connected to the positive output terminal of the rectifier circuit 11, the second end of the first resistor R1 is connected to the input terminal of the processing circuit, the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is grounded.

[0053] The voltage after voltage division by the voltage divider circuit is represented by V2.

[0054] In the power supply system provided in this application embodiment, the processing circuit includes: a first comparator U1, a second comparator U2, and a flip-flop 22.

[0055] The negative input terminal of the first comparator U1 is connected to the output terminal of the voltage sampling circuit and is used to input the voltage V2 after voltage division. The positive input terminal of the first comparator U1 is connected to the first voltage threshold Vref1. The output terminal of the first comparator U1 is connected to the reset terminal of the flip-flop 22. The output terminal of the flip-flop 22 is connected to the input terminal of the control circuit 30. The output terminal of the control circuit 30 is connected to the execution switch 40.

[0056] The positive input terminal of the second comparator U2 is connected to the output terminal of the voltage sampling circuit and is used to input the voltage V2 after voltage division. The negative input terminal of the second comparator U2 is connected to the second voltage threshold Vref2. The output terminal of the second comparator U2 is connected to the input terminal of the flip-flop 22.

[0057] The first voltage threshold Vref1 is less than the second voltage threshold Vref2.

[0058] The working principle is explained below.

[0059] During the switching process of the switch, there is no voltage at the first terminal of the switch circuit 101, no input voltage to the voltage sampling circuit 10, and the capacitor C discharges through the first resistor R1 and the second resistor R2.

[0060] The voltage across the second resistor R2 is:

[0061]

[0062] Where t represents time. V2(t) outputs high and low levels via the first comparator U1 and the second comparator U2. The output signal of the first comparator U1 serves as the reset signal for the flip-flop 22; when the first comparator U1 outputs a high level, the flip-flop 22 is reset. The output signal of the second comparator U2 serves as the input signal for the flip-flop 22; the flip-flop 22 defaults to outputting a high level, energizing the relay in the control circuit 30. The output signal of the flip-flop 22 toggles when the input signal is a falling edge. That is, when the output of the second comparator U2 changes from a high level to a low level (i.e., at the falling edge), the flip-flop 22 toggles, and the output signal changes from a high level to a low level.

[0063] The first voltage threshold Vref1 and the second voltage threshold Vref2 can be set according to the grid voltage recovery time t1 and the power outage time t2, respectively. For example, the first comparator U1 is used to determine the grid recovery and the second comparator U2 is used to determine the grid outage.

[0064]

[0065] When t1 > t2, i.e., Vref1 < Vref2, flip-flop 22 outputs a high level by default, triggered on the falling edge. The specific operating logic is as follows:

[0066] 1) During initial operation, the power grid is normal, and V2 > Vref2 > Vref1. The comparator operates on the principle that it outputs a high level when the voltage at its positive input is higher than that at its negative input, and a low level when the voltage at its positive input is lower than that at its negative input. Therefore, the first comparator U1 outputs 0, the second comparator U2 outputs 1, the trigger 22 outputs 1, the relay in the control circuit 30 is activated, and this in turn controls the actuator switch 40 to activate, supplying power to both the first and second category loads (i.e., both important and routine loads). Here, "0" represents a low level and "1" represents a high level.

[0067] 2) When the power grid fails, the switch moves to the second moving contact B, i.e., switches to the off-grid port. The power outage time is the second time period t2. During the second time period t2, the voltage sampling circuit has no voltage input, C discharges, and V2 gradually decreases. When it decreases to a value greater than Vref1 and less than Vref2, the first comparator U1 still outputs 0, while the output of the second comparator U2 changes from 1 to 0. That is, the input signal of trigger 22 drops from a high level to a low level, triggering the falling edge of trigger 22, and the output of trigger 22 switches from 1 to 0. The relay in the control circuit 30 is disconnected, which in turn controls the execution switch 40 to open, and the second type of load stops receiving power, i.e., the regular load is not supplied with power.

[0068] 3) In the off-grid state, as the voltage recovers, V2 gradually increases. When it increases to a level greater than Vref2, the output of the first comparator U1 remains 0, and the output of the second comparator U2 changes from 0 to 1. However, since the trigger 22 is triggered by a falling edge, the output of the second comparator U2 is a rising edge at this time. Therefore, the output of the trigger 22 remains 0, the relay in the control circuit 30 remains open, and the execution switch 40 also remains open, meaning that the normal load is not powered.

[0069] 4) When the power grid is restored, the switch is switched to the first moving contact A, that is, the power grid is connected. The restoration time is the first time period t1. During the first time period t1, V2 will drop to less than Vref1. The output of the first comparator U1 changes from 0 to 1, the output of the second comparator U2 is 0, the reset signal of the trigger 22 is valid, the first comparator U1 resets the trigger 22 to 1, the relay in the control circuit 30 is activated, and then the execution switch 40 is activated to supply power to the second type of load.

[0070] 5) Under grid-connected conditions, after the grid is normal, V2 gradually increases. When it increases to more than Vref2, the output of the first comparator U1 changes from 1 to 0, and the output of the second comparator U2 changes from 0 to 1. However, since the trigger 22 is triggered by the falling edge, the output of the second comparator U2 is the rising edge at this time. Therefore, the output of the trigger 22 remains 1, and the relay in the control circuit 30 remains in the energized state.

[0071] It should be understood that the above are only examples illustrating five operating conditions. Furthermore, V2 changes between off-grid power supply and grid restoration, specifically from V2 > Vref2 > Vref to Vref2 > Vref1 > V2. This change in V2 also includes the intermediate state of Vref2 > V2 > Vref1. Similarly, between grid restoration and grid normalization, V2 changes again, from Vref2 > Vref1 > V2 to V2 > Vref2 > Vref1. This change in V2 also includes the intermediate state of Vref2 > V2 > Vref1.

[0072] For a clearer understanding, please refer to the table below.

[0073]

[0074] See Figure 4 This figure is a schematic diagram of another power supply system provided in an embodiment of this application.

[0075] For ease of installation and maintenance, the distribution box 200 in the power supply system provided in this application embodiment further includes: a main switch K, a first branch switch Q1, and a second branch switch Q2.

[0076] The first end of the main switch K is connected to the stationary contact C of the changeover switch S1, and the second end of the main switch K is connected to the first end of the switch circuit 101.

[0077] The second terminal of the switching circuit 101 is connected to the second type of load through the first branch switch Q1, and the second terminal of the main switch K is connected to the first type of load through the second branch switch Q2.

[0078] When it is necessary to disconnect power to all loads, the main switch K can be operated to open. This way, regardless of whether the first branch switch Q1 and the second branch switch Q2 are closed, as long as the main switch K is open, both Class I and Class II loads will be de-energized. Furthermore, during maintenance, because only one wire is connected to the distribution box, regardless of whether the power converter or the grid is supplying power, the main switch K can be controlled to disconnect the power supply path to all loads, preventing electric shock. When it is necessary to disconnect power to Class I loads, the second branch switch Q2 can be operated to open; when it is necessary to disconnect power to Class II loads, the first branch switch Q1 can be operated to open, avoiding the risk of electric shock during circuit maintenance.

[0079] Based on the power supply system provided in the above embodiments, this application also provides a distribution box, which will be described in detail below.

[0080] The power distribution box provided in this application embodiment includes: a switching circuit;

[0081] The first end of the switching circuit is connected to the stationary contact of the switching switch, and the second end of the switching circuit is used to connect to the second type of load; wherein the first moving contact of the switching switch is connected to the grid-connected port of the power converter, and the first moving contact of the switching switch is also used to connect to the power grid, and the second moving contact of the switching switch is connected to the off-grid port of the power converter.

[0082] The first terminal of the switching circuit is used to connect to the power supply of the first type of load; wherein, the power supply priority of the first type of load is higher than that of the second type of load;

[0083] A switching circuit used to disconnect when the power grid fails.

[0084] The specific details of the distribution box provided in this application embodiment can be found in Figure 1, which describes the distribution box in the power supply system and its working principle. Further details will not be repeated here.

[0085] The distribution box provided in this application embodiment can connect the power grid and the power converter through a single wire without damaging the building's wall structure.

[0086] The distribution box provided in this application embodiment includes a switching circuit comprising a voltage sampling circuit, a processing circuit, and an execution switch. The input terminal of the voltage sampling circuit is connected to the first terminal of the switching circuit, used to sample the voltage at the first terminal of the switching circuit, and to rectify and divide the sampled voltage to obtain a divided voltage, which is then sent to the processing circuit. The input terminal of the processing circuit is connected to the output terminal of the voltage sampling circuit, and the output terminal of the processing circuit is connected to the execution switch, used to compare the divided voltage with a voltage threshold to obtain a comparison result, which is used to drive the execution switch to open or close. For example, the execution switch can be a MOSFET or an IGBT.

[0087] In another possible implementation, the switching circuit further includes a control circuit; the input of the control circuit is connected to the output of the processing circuit, and the output of the control circuit is connected to the execution switch; the processing circuit sends the comparison result to the control circuit; the control circuit is used to drive the execution switch to open or close according to the comparison result. For example, the execution switch is a contactor, and the control circuit includes a relay, which is used to drive the contactor to operate. The output signal of the processing circuit is insufficient to directly drive the contactor to operate, and a relay is needed as an intermediate device for driving.

[0088] The specific implementation and working principle of the switching circuit can be found in Figure 2 of the above power supply system embodiment, and will not be repeated here.

[0089] The processing circuit includes: a first comparator, a second comparator, and a flip-flop;

[0090] The negative input terminal of the first comparator is connected to the output terminal of the voltage sampling circuit, the positive input terminal of the first comparator is connected to the first voltage threshold, and the output terminal of the first comparator is connected to the reset terminal of the flip-flop.

[0091] The positive input of the second comparator is connected to the voltage sampling circuit, the negative input of the second comparator is connected to the second voltage threshold, and the output of the second comparator is connected to the input of the flip-flop.

[0092] The first voltage threshold is less than the second voltage threshold.

[0093] For details on the implementation and working principle of the processing circuit, please refer to the above power supply system embodiment. Figure 3 The details of the introduction will not be repeated here.

[0094] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0095] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power supply system, characterized in that, include: Power converters, switching devices, and distribution boxes; The first moving contact of the switching switch is connected to the grid-connected port of the power converter, and the first moving contact of the switching switch is also used to connect to the power grid; the second moving contact of the switching switch is connected to the off-grid port of the power converter; the stationary contact of the switching switch is connected to the first end of the distribution box, and the second end of the distribution box is used to connect to the load.

2. The power supply system according to claim 1, characterized in that, The distribution box includes a switching circuit; The stationary contact of the switching switch is connected to the first terminal of the switching circuit, which is used to connect to a first type of load; the second terminal of the switching circuit is used to connect to a second type of load; the power supply priority of the first type of load is higher than that of the second type of load. The switching circuit is used to disconnect when the power grid fails.

3. The power supply system according to claim 2, characterized in that, The switching circuit includes a voltage sampling circuit, a processing circuit, and an execution switch; The input terminal of the voltage sampling circuit is connected to the first terminal of the switching circuit and is configured to sample the voltage of the first terminal of the switching circuit, and to rectify and divide the sampled voltage to obtain the voltage after voltage division. The input terminal of the processing circuit is connected to the output terminal of the voltage sampling circuit, and the output terminal of the processing circuit is connected to the execution switch. The processing circuit is configured to compare the voltage after voltage division with a voltage threshold to obtain a comparison result, which is used to control the execution switch to open or close.

4. The power supply system according to claim 3, characterized in that, The processing circuit includes: a first comparator, a second comparator, and a flip-flop; The negative input terminal of the first comparator is connected to the output terminal of the voltage sampling circuit, the positive input terminal of the first comparator is connected to the first voltage threshold, and the output terminal of the first comparator is connected to the reset terminal of the flip-flop; the output terminal of the flip-flop is connected to the execution switch. The positive input terminal of the second comparator is connected to the output terminal of the voltage sampling circuit, the negative input terminal of the second comparator is connected to the second voltage threshold, and the output terminal of the second comparator is connected to the input terminal of the flip-flop; wherein, the first voltage threshold is less than the second voltage threshold.

5. The power supply system according to claim 4, characterized in that, The trigger is a falling edge trigger.

6. The power supply system according to any one of claims 3-5, characterized in that, The switching circuit further includes: a control circuit; the input terminal of the control circuit is connected to the output terminal of the processing circuit; the output terminal of the control circuit is connected to the execution switch; The actuator switch is a contactor; the control circuit includes a relay, which is connected in series in the power supply circuit of the contactor.

7. The power supply system according to any one of claims 3-5, characterized in that, The voltage sampling circuit includes a rectifier circuit, a filter circuit, and a voltage divider circuit; The input terminal of the rectifier circuit is connected to the first terminal of the switching circuit, the output terminal of the rectifier circuit is connected to the input terminal of the filter circuit, the output terminal of the filter circuit is connected to the input terminal of the voltage divider circuit, and the output terminal of the voltage divider circuit is connected to the input terminal of the processing circuit.

8. The power supply system according to any one of claims 2-5, characterized in that, The distribution box also includes: a main switch, a first branch switch, and a second branch switch; The first end of the main switch is connected to the stationary contact of the switching switch, and the second end of the main switch is connected to the first end of the switching circuit. The second terminal of the switching circuit is connected to the second type of load through the first branch switch, and the second terminal of the main switch is connected to the first type of load through the second branch switch.

9. The power supply system according to any one of claims 1-4, characterized in that, The DC side of the power converter is used to connect to at least one of a battery or a photovoltaic module.

10. A distribution box, characterized in that, include: Switching circuit; The first end of the switching circuit is connected to the stationary contact of the switching switch, and the second end of the switching circuit is used to connect to the second type of load; wherein, the first moving contact of the switching switch is connected to the grid-connected port of the power converter, and the first moving contact of the switching switch is also used to connect to the power grid, and the second moving contact of the switching switch is connected to the off-grid port of the power converter; The first terminal of the switching circuit is used to connect to a first type of load; wherein the power supply priority of the first type of load is higher than that of the second type of load; The switching circuit is used to disconnect when the power grid fails.

11. The distribution box according to claim 10, characterized in that, The switching circuit includes a voltage sampling circuit, a processing circuit, and an execution switch; The input terminal of the voltage sampling circuit is connected to the first terminal of the switching circuit and is configured to sample the voltage of the first terminal of the switching circuit, and to rectify and divide the sampled voltage to obtain the voltage after voltage division. The input terminal of the processing circuit is connected to the output terminal of the voltage sampling circuit, and the output terminal of the processing circuit is connected to the execution switch. It is configured to compare the voltage after voltage division with a voltage threshold to obtain a comparison result. The comparison result is used to drive the execution switch to open or close.

12. The distribution box according to claim 11, characterized in that, The switching circuit further includes a control circuit; the input terminal of the control circuit is connected to the output terminal of the processing circuit, and the output terminal of the control circuit is connected to the execution switch. The processing circuit sends the comparison result to the control circuit; The control circuit is configured to drive the execution switch to open or close based on the comparison result.

13. The distribution box according to claim 12, characterized in that, The processing circuit includes: a first comparator, a second comparator, and a flip-flop; The negative input terminal of the first comparator is connected to the output terminal of the voltage sampling circuit, the positive input terminal of the first comparator is connected to the first voltage threshold, and the output terminal of the first comparator is connected to the reset terminal of the flip-flop. The positive input terminal of the second comparator is connected to the output terminal of the voltage sampling circuit, the negative input terminal of the second comparator is connected to the second voltage threshold, and the output terminal of the second comparator is connected to the input terminal of the flip-flop; wherein, the first voltage threshold is less than the second voltage threshold.

Images