Photovoltaic panel turn-off control device and photovoltaic group string turn-off control system

Abstract

The utility model discloses a photovoltaic panel turn-off control device and a photovoltaic group string turn-off control system, comprising a static switch, a power supply module, an energy storage module and three relays, through the cooperation of the energy storage module, the power supply module, the static switch and the relays, the turn-off control of the photovoltaic panel is realized. The turn-off control device provided by the utility model is simple in circuit structure and low in cost of adopted circuit components, and has the characteristics of low hardware cost and the like compared with a turn-off device of a photovoltaic panel in the prior art. The utility model also provides a photovoltaic string turn-off control system.

Description

Technical Field

[0001] The utility model relates to the shutdown control of a photovoltaic panel, in particular to a photovoltaic panel shutdown control device and a photovoltaic string shutdown control system. Background Art

[0002] The existing shutdown control of a photovoltaic panel generally uses an isolated power supply to completely isolate the control circuit and the high-voltage circuit. The control circuit controls an MOS transistor to assist in arc extinguishing of a relay, protecting the contacts of the relay from being damaged by an arc when shutting down and releasing the shutdown. However, this shutdown device uses an isolated power supply and a magnetic latching relay, and the cost of circuit components is relatively high, making the hardware circuit cost of the entire shutdown device relatively too high. Summary of the Utility Model

[0003] In order to overcome the deficiencies of the prior art, one of the purposes of the utility model is to provide a photovoltaic panel shutdown control device, which can solve the problems such as high hardware cost existing in the existing shutdown control of a photovoltaic panel.

[0004] Another purpose of the utility model is to provide a photovoltaic string shutdown control system, which can solve the problems such as high hardware cost existing in the existing shutdown control of a photovoltaic system.

[0005] One of the purposes of the utility model is realized by adopting the following technical scheme:

[0006] A photovoltaic panel shutdown control device includes a static switch, a power supply module, an energy storage module, a first relay, a second relay, and a third relay; wherein, the first relay, the second relay, and the third relay are all electromagnetic relays, and the first relay is provided with a first normally open contact, a second normally open contact, and a first normally closed contact; the second relay is provided with a second normally closed contact; the third relay is provided with a third normally open contact;

[0007] The first end of the first relay is connected to the positive pole of the power supply, and the second end is connected to the negative pole of the power supply; the first end of the second relay is connected to the positive pole of the power supply, and the second end is connected to the negative pole of the power supply; the first end of the third relay is electrically connected to the second end of the power supply module, and the second end is electrically connected to the third end of the power supply module; the second end of the first relay is also electrically connected to the second end of the second relay through the first normally open contact;

[0008] The first end of the static switch is electrically connected to the third end of the power supply module through the third normally open contact. The second end of the static switch is electrically connected to the second end of the power supply module. The third end of the static switch is electrically connected to the first end of the power supply module through the first normally open contact and the first normally closed contact. The third end of the static switch is also electrically connected to the positive electrode of the photovoltaic panel in the photovoltaic string, and the second end is also electrically connected to the negative electrode of the photovoltaic panel.

[0009] One end of the second normally closed contact is electrically connected to the positive electrode of the photovoltaic panel and the third end of the static switch, and the other end of the second normally closed contact is electrically connected to the negative electrode of the photovoltaic panel and the second end of the static switch. The positive electrode of the energy storage module is connected between the first normally open contact and the first normally closed contact, and the negative electrode is electrically connected to the second end of the power supply module.

[0010] When the photovoltaic panel is turned off, the power supply is disconnected, the first relay loses power, and the second relay loses power. Then the first normally open contact opens, the first normally closed contact closes, the energy storage module discharges, the power supply module gets power, the third relay gets power, the third normally open contact closes, and the static switch conducts. After that, the second normally closed contact closes, and the positive and negative electrodes of the photovoltaic panel are short-circuited, and the photovoltaic panel is in the off state. And when the energy storage module finishes discharging, the power supply module is powered off, the third relay loses power, the third normally open contact opens, and the static switch is cut off.

[0011] When the photovoltaic panel is released from being turned off, the power supply is connected, the first relay gets power, the first normally open contact closes, the first normally open contact closes, the first normally closed contact opens. Then the second relay gets power, the second normally closed contact opens, the short circuit between the positive and negative electrodes of the photovoltaic panel is released, and the photovoltaic panel starts to charge the energy storage module, and the photovoltaic panel is in the state of being released from being turned off.

[0012] Further, the delay action time of the second relay losing power is greater than the delay action time of the first relay losing power.

[0013] Further, it also includes a first delay circuit and a second delay circuit. Among them, the first end of the first relay is also electrically connected to the second end of the first relay through the first delay circuit. The first end of the second relay is also electrically connected to the second end of the second relay through the second delay circuit.

[0014] Further, both the first delay circuit and the second delay circuit are RC delay circuits.

[0015] Further, the first delay circuit includes a first resistor and a first capacitor, and one end of the first resistor is electrically connected to the first end of the first relay, and the other end is electrically connected to the second end of the first relay through the first capacitor;

[0016] The second delay circuit includes a second resistor and a second capacitor, and one end of the second resistor is electrically connected to the first end of the second relay, and the other end is electrically connected to the second end of the second relay through the second capacitor.

[0017] Further, it further includes a first diode and a second diode; the positive electrode of the first diode is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the first relay; the positive electrode of the second diode is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the second relay;

[0018] Further, it further includes a third resistor and a fourth resistor; one end of the third resistor is electrically connected to the first end of the static switch, and the other end of the third resistor is electrically connected to the negative electrode of the photovoltaic panel and the second end of the static switch; one end of the fourth resistor is electrically connected to the first end of the static switch, and the other end is electrically connected to the third end of the power supply module through the first normally open contact.

[0019] Further, the static switch is a MOS transistor, wherein the first end of the static switch is the gate of the MOS transistor, the second end of the static switch is the source of the MOS transistor, and the third end of the static switch is the drain of the MOS transistor.

[0020] Further, the first normally open contact is also electrically connected to the photovoltaic string shutdown controller, so that the photovoltaic string shutdown controller determines whether the photovoltaic panel is in a shutdown state according to the first normally open contact.

[0021] The second object of the present invention is achieved by the following technical solutions:

[0022] A photovoltaic string shutdown control system includes a plurality of photovoltaic strings connected in parallel; wherein, each photovoltaic string includes a plurality of photovoltaic panels connected in series; it further includes a photovoltaic panel shutdown control device adopted in the first object of the present invention; wherein, each photovoltaic panel is correspondingly provided with one of the photovoltaic panel shutdown control devices.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The present utility model charges the energy storage module to assist in arc extinguishing of the relay contacts and uses it as the power source for turning off the photovoltaic panel, so that the logic of the turn-off control of the photovoltaic panel is simple and reliable, ensuring the safety of the turn-off control of the photovoltaic panel. At the same time, when the present utility model executes the turn-off, the turn-off power supply is supplied by the energy storage module. Furthermore, the present utility model can use a non-isolated power supply as the turn-off control power supply and a conventional electromagnetic relay as the turn-off control element, making the circuit structure simple and reducing the hardware cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. is a schematic circuit connection diagram of a photovoltaic panel turn-off control device provided by the present utility model and a photovoltaic panel;

[0026] Figure 2 is Figure 1 a schematic connection diagram of the first relay, the second relay, the first delay circuit, and the second delay circuit in

[0027] Figure 3 FIG. is a schematic circuit connection diagram of a photovoltaic panel turn-off control device of multiple photovoltaic panels in a photovoltaic string in a photovoltaic string turn-off control system provided by the present utility model and a photovoltaic panel;

[0028] Figure 4 FIG. is a schematic circuit diagram of the connection relationship between a photovoltaic string turn-off controller and a power supply and an inverter in a photovoltaic string turn-off control system provided by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, in combination with the accompanying drawings and specific embodiments, the present utility model will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0030] Embodiment 1

[0031] The present utility model provides a photovoltaic panel turn-off control device for realizing the turn-off control of photovoltaic panels in a photovoltaic string, and can solve the problems of relatively complex control circuits and high hardware costs in the existing photovoltaic panel turn-off devices in a photovoltaic string.

[0032] Preferably, the present utility model provides a preferred embodiment, a photovoltaic panel turn-off control device, as Figure 1 shown, including a static switch, a power module U, an energy storage module, a first relay KN, a second relay KL, and a third relay KM.

[0033] Among them, the first relay KN, the second relay KL, and the third relay KM are all electromagnetic relays.

[0034] The first relay KN is provided with a first normally open contact KN11, a second normally open contact KN12, and a first normally closed contact KN13. Among them, when the first relay KN is in a de-energized state, the contacts of the first normally open contact KN11 and the second normally open contact KN12 are both in an open state, and the contact of the first normally closed contact KN13 is in a closed state; on the contrary, when the first relay KN is in an energized state, the contacts of the first normally open contact KN11 and the second normally open contact KN12 are both in a closed state, and the contact of the first normally open contact KN13 is in an open state.

[0035] The second relay KL is provided with a first normally closed contact KL21. Similarly, when the second relay KL is in a de-energized state, the first normally closed contact KL21 is in a closed state; on the contrary, when the second relay KL is in an energized state, the first normally closed contact KL21 is in an open state.

[0036] The third relay KM is provided with a third normally open contact KM131. Similarly, when the third relay KM is in a de-energized state, the contact of the third normally open contact KM131 is in an open state; on the contrary, when the third relay KM is in an energized state, the contact of the third normally open contact KM131 is in a closed state.

[0037] The first end of the first relay KN is electrically connected to the positive pole (+24V) of the power supply, and the second end is electrically connected to the negative pole (0V) of the power supply. The first end of the second relay KL is electrically connected to the positive pole (+24V) of the power supply, and the second end is electrically connected to the negative pole (0V) of the power supply.

[0038] When the power supply loses power, that is, the A1 - A2 circuit is disconnected: both the first relay KN and the second relay KL will lose power; on the contrary, when the power supply is normal, both the first relay KN and the second relay KL will be energized.

[0039] The first end of the third relay KM is electrically connected to the second end (port 2) of the power module U, and the second end is connected between the third end (port 3) of the power module U and the third normally open contact KM31.

[0040] The static switch is preferably a MOS transistor Q. Among them, the drain D of the MOS transistor Q is electrically connected to the positive pole of the photovoltaic panel, the source S of the MOS transistor Q is electrically connected to the negative pole of the photovoltaic panel, and the gate G of the MOS transistor Q is electrically connected to the third end (port 3) of the power module U through the third normally open contact KM31.

[0041] The positive and negative electrodes of the photovoltaic panel are also electrically connected to the inverter in the power grid for power generation. In the present utility model, static switches are connected in parallel at both ends of the photovoltaic panel, and the off-control of the photovoltaic panel is realized through the cooperation of the static switches and the relay. In this way, when it is necessary to turn off the photovoltaic panel in case of a fire or an abnormal situation, etc., it can be achieved by controlling the disconnection of the power supply.

[0042] Further, the drain D of the MOS transistor Q is also electrically connected to the first end (port 1) of the power supply module U through the first two normally open contacts KN12 and the first three normally closed contacts KN13, and the source S of the MOS transistor Q is also electrically connected to the second end (port 2) of the power supply module U.

[0043] The positive electrode of the energy storage module is connected between the first two normally open contacts KN12 and the first three normally closed contacts KN13, and the negative electrode is electrically connected to the second end (port 2) of the power supply module U.

[0044] One end of the second one normally closed contact KL21 is electrically connected to the positive electrode of the photovoltaic panel and the drain D of the MOS transistor Q, that is, one end of the second one normally closed contact KL21 is connected between the drain D of the MOS transistor Q and the first two normally open contacts KN12. The other end of the second one normally closed contact KL21 is electrically connected to the negative electrode of the photovoltaic panel, the source S of the MOS transistor Q, and the second end (port 2) of the power supply module U.

[0045] When turning off the photovoltaic panel, the power supply is disconnected: the first relay KN loses power, the second relay KL loses power, then the first two normally open contacts KN12 open, the first three normally closed contacts KN13 close, the energy storage module discharges, the power supply module U gets power, the third relay KM gets power, the third one normally open contact KM31 closes, and the MOS transistor Q conducts; afterwards, the second one normally closed contact KL21 closes, and the positive and negative of the photovoltaic panel are short-circuited, and the photovoltaic panel is in the off state. In the present utility model, in the state where the energy storage module discharges, it is ensured that the action of turning on the MOS transistor Q precedes the closing action of the second one normally closed contact KL21, so as to protect the second one relay KL1 from being damaged by the DC arc when it operates, so as to ensure the reliable off of the photovoltaic panel. When the energy storage module finishes discharging, the power supply module U is powered off, the third relay KM loses power, the third one normally open contact KM31 opens, and the MOS transistor Q is cut off, and the off of the photovoltaic panel is completed.

[0046] During the process of turning off the photovoltaic panel, the power supply for turning off is provided by the energy storage module, and after the photovoltaic panel is turned off, there are no energized circuit devices in the circuit, ensuring the lowest circuit power consumption. At the same time, through the cooperative action of the first relay KN and the second relay KL, it can also be ensured that during the process of turning off the photovoltaic panel, by ensuring the reliable conduction of the MOS transistor Q, the second one normally closed contact KL21 is protected from being damaged by the DC arc when it closes.

[0047] Preferably, in this embodiment, it is necessary to ensure that the MOS transistor Q is turned on before the second normally-closed contact KL21 is closed. Therefore, in this embodiment, the delay action time of the power-off of the second relay KL needs to be greater than the delay action time of the power-off of the first relay KN. In this way, it can be ensured that the MOS transistor Q is turned on first, and when the MOS transistor Q is turned on, the contact of the second normally-closed contact KL21 is closed, avoiding damage to the contact by the DC arc during operation.

[0048] Preferably, both the first relay KN and the second relay KL can adopt relays with a delay function, and it is only necessary to ensure that the delay action time of the power-off of the second relay KL is greater than the delay action time of the power-off of the first relay KN. More specifically, the delay working time of the power-off of the first relay KL is greater than 300 ms to meet the requirements of the shutdown system for low-voltage ride-through of the power grid.

[0049] More preferably, as Figure 2 shown, the present invention further includes a first delay circuit and a second delay circuit. Among them, one end of the first delay circuit is electrically connected to the first end of the first relay KN, and the other end is electrically connected to the second end of the first relay KN. One end of the second delay circuit is electrically connected to the first end of the second relay KL, and the other end is electrically connected to the second end of the second relay KL. By setting the delay circuit, it can be ensured that when the power supply is disconnected, after the first relay KN loses power, when the first normally-open contact KN12 is opened and the first normally-closed contact KN13 is closed, the energy storage module discharges, the power supply module U is powered on, the third relay KM is powered on, the third normally-open contact KM31 is closed, and after the MOS transistor Q is turned on, the second relay KL loses power to control the second normally-closed contact KL21 to close, ensuring that when the MOS transistor Q is turned on, the second normally-closed contact KL21 is closed again to avoid damage to the contact by the DC arc during operation. After that, when the energy storage module finishes discharging, the power supply module U is powered off, the third relay KM loses power, the third normally-open contact KM31 is opened, and the MOS transistor Q is cut off.

[0050] More preferably, both the first delay circuit and the second delay circuit are RC delay circuits. That is, the first delay circuit includes a first resistor R1 and a first capacitor C1, and one end of the first resistor R1 is electrically connected to the first end of the first relay KN, and the other end is electrically connected to the second end of the first relay KN through the first capacitor C1. Similarly, the second delay circuit includes a second resistor R2 and a second capacitor C2, and one end of the second resistor R2 is electrically connected to the first end of the second relay KL, and the other end is electrically connected to the second end of the second relay KL through the second capacitor C2.

[0051] Meanwhile, when the photovoltaic panel is released from shutdown, by energizing the power supply, at this time: the first relay KN is energized, the first normally open contact KN11 closes, the second normally open contact KN12 closes, and the third normally closed contact KN13 opens, then the second relay KL is energized, and the first normally closed contact KL21 opens, and the positive and negative poles of the photovoltaic panel are released from short circuit and start charging the energy storage module. That is, when the first normally closed contact KL21 opens, the photovoltaic panel starts generating electricity to the energy storage module, and charges through the energy storage power supply to achieve the function of assisting arc extinguishing when the first normally closed contact KL21 opens, ensuring that the contact of the first normally closed contact KL21 will not be damaged by the DC arc when it opens.

[0052] Preferably, the energy storage module in the present invention is a capacitor C3. The positive pole of the capacitor C3 is connected between the second normally open contact KN12 and the third normally closed contact KN13, and the negative pole is electrically connected to the second terminal of the power supply module U. That is, the present invention uses the method of capacitor charging to assist arc extinguishing to ensure that the first normally closed contact KL21 of the second relay KL is not damaged by DC when it operates; at the same time, this capacitor can also be used as the power supply of the photovoltaic panel when it is turned off, avoiding the use of an additional power supply to turn off the photovoltaic panel, ensuring that the control logic of the photovoltaic panel during shutdown and release from shutdown is simple, reliable, and the control circuit is simple; at the same time, this power supply uses a non-isolated power supply, which can greatly reduce the hardware cost of the circuit.

[0053] The present invention also realizes the isolation between the photovoltaic panel shutdown control circuit and the high-voltage circuit of the photovoltaic panel main circuit by means of the isolation of the contacts and coils of the relay, ensuring the safety and reliability of the photovoltaic panel shutdown.

[0054] Meanwhile, the first relay KN, the second relay KL, and the third relay KM in the present invention are all conventional relays, and there is no need to use magnetic latching relays, which reduces the hardware cost of the circuit.

[0055] Preferably, one end of the first normally open contact KN11 in the present invention is also electrically connected to the negative pole of the power supply and the other end is electrically connected to the photovoltaic string shutdown controller (A3 in the figure), forming a loop of A2 - A3, which can enable the first normally open contact KN11 to feedback the shutdown state of the photovoltaic panel to the photovoltaic string shutdown controller. For example, when the photovoltaic panel is shut down, the first relay KN loses power and the first normally open contact KN11 opens. The photovoltaic string shutdown controller can know that the photovoltaic panel is shut down according to the open state of the first normally open contact KN11; on the contrary, when the photovoltaic panel is released from shutdown, since the first relay KN is energized and the first normally open contact KN11 closes, the photovoltaic string shutdown controller can conclude that the photovoltaic panel is in the state of being released from shutdown according to the closed state of the first normally open contact KN11. Among them, the photovoltaic string shutdown controller refers to the control device used for shutting down the photovoltaic string.

[0056] Furthermore, the utility model further includes a first diode VD1, a second diode VD2, a third resistor R3 and a fourth resistor R4. Among them, the positive electrode of the first diode VD1 is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the first relay KN. The positive electrode of the second diode VD2 is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the second relay KL. One end of the third resistor R3 is electrically connected to the gate of the MOS transistor Q, and the other end of the third resistor R3 is electrically connected to the source S of the MOS transistor Q and the second end (port 2) of the power supply module U. One end of the fourth resistor R4 is electrically connected to the gate G of the MOS transistor Q, and the other end is electrically connected to the third end (port 3) of the power supply module U through a third normally open contact KM31. By setting the first diode VD1 and the second diode VD2, the utility model utilizes the one-way conductivity of the diode to ensure the stability of the delay return time of the first relay and the second relay.

[0057] Embodiment 2

[0058] Based on Embodiment 1, the utility model further provides a method for controlling the shutdown of a photovoltaic panel, which is applied to a device for controlling the shutdown of a photovoltaic panel adopted in Embodiment 1 of the utility model. The method includes:

[0059] When the photovoltaic panel is shut down, by disconnecting the power supply, the first relay loses power and the second relay loses power, then the first two normally open contacts open, the first three normally closed contacts close, the energy storage module discharges, the power supply module gets power, the third relay gets power, the third normally open contact closes, and the static switch conducts; afterwards, the second one normally closed contact closes, the positive and negative poles of the photovoltaic panel are short-circuited and power generation stops, and the photovoltaic panel is in a shutdown state; and when the energy storage module finishes discharging, the power supply module is powered off, the third relay loses power, the third normally open contact opens, and the static switch is cut off.

[0060] When the photovoltaic panel is released from shutdown, by connecting the power supply, the first relay gets power, the first one normally open contact closes, the first two normally open contacts close, the first three normally closed contacts open, then the second relay gets power, the second one normally closed contact opens, the positive and negative poles of the photovoltaic panel are released from short-circuit, and the photovoltaic panel starts to charge the energy storage module, and the photovoltaic panel is in a state of being released from shutdown.

[0061] Embodiment 3

[0062] Based on Embodiment 1, the utility model further provides another embodiment, a photovoltaic string shutdown control system, which includes a plurality of photovoltaic strings connected in parallel and a device for controlling the shutdown of a photovoltaic panel provided in Embodiment 1; among them, each photovoltaic string includes a plurality of photovoltaic panels connected in series, and each photovoltaic panel corresponds to a device for controlling the shutdown of a photovoltaic panel.

[0063] Each photovoltaic string includes a plurality of photovoltaic panels connected in series. That is, the positive electrode of one photovoltaic panel is electrically connected to the negative electrode of the previous photovoltaic panel, and the negative electrode is electrically connected to the positive electrode of the next photovoltaic panel to form a photovoltaic string. Each photovoltaic panel is correspondingly connected to a photovoltaic panel shutdown control device adopted in the first embodiment provided by the present invention.

[0064] Specifically, as Figure 3 and Figure 4 shown, the number of photovoltaic panels is set to n, that is, n photovoltaic panels are connected in series. The positive and negative electrodes of the photovoltaic panels are electrically connected to an inverter and are connected to the power grid through the inverter to transmit electric energy to the power grid. Each photovoltaic panel is correspondingly connected to a photovoltaic panel shutdown control device. The external power supply is provided by a photovoltaic string shutdown controller, wherein the photovoltaic string shutdown controller includes an AC-DC converter and a main control module. The external power supply is electrically connected to the main control module through the AC-DC converter, and then the main control module provides a power supply to each photovoltaic panel shutdown control device.

[0065] Specifically, as Figure 3 and Figure 4 shown, for the first photovoltaic panel shutdown control device corresponding to the first photovoltaic panel: the first end of the first relay KN1 is connected to the positive electrode of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string shutdown controller; the second end of the first relay KN1 is connected to the negative electrode of the power supply, that is, electrically connected to the second end (port 2) of the main control module of the photovoltaic string shutdown controller.

[0066] At the same time, the first end of the second relay KL1 is connected to the positive electrode of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string shutdown controller; the second end of the second relay KL1 is connected to the negative electrode of the power supply, that is, electrically connected to the second end (port 2) of the main control module of the photovoltaic string shutdown controller.

[0067] The second end of the first relay KN1 is also electrically connected to the second end of the second relay KL1 through the first normally open contact KN111. The first normally open contact KN111 is also electrically connected to the third end (port 3) of the main control module of the photovoltaic string shutdown controller, and is used to feed back the shutdown state of the photovoltaic panel to the photovoltaic string shutdown controller.

[0068] The drain D of the MOS transistor Q1 is electrically connected to the positive electrode of the photovoltaic panel, and the source S is electrically connected to the negative electrode of the photovoltaic panel. The drain D of the MOS transistor Q1 is also electrically connected to the first end (port 1) of the power module U1 through the second normally open contact KN112 and the third normally closed contact KN113. The source S of the MOS transistor Q1 is electrically connected to the second end (port 2) of the power module U1, and the gate G of the MOS transistor Q1 is electrically connected to the third end (port 3) of the power module U1 through the third normally open contact KM131.

[0069] One end of the second one normally closed contact KL121 is electrically connected to the drain D of the MOS transistor Q1 and the positive electrode of the photovoltaic panel, and the other end of the second one normally closed contact KL121 is electrically connected to the negative electrode of the photovoltaic panel, the source S of the MOS transistor Q1, and the second end (port 2) of the power supply module U1.

[0070] For the energy storage module, that is, the positive electrode of the capacitor C31 is connected between the first two normally open contacts KN112 and the first three normally open contacts KN113, and the negative electrode is electrically connected to the second end (port 2) of the power supply module U1.

[0071] One end of the third relay KM1 is electrically connected to the second end (port 2) of the power supply module U1, and the other end is electrically connected to the third end (port 3) of the power supply module U1.

[0072] The first diode VD11 is connected between the positive electrode of the power supply and the first end of the first relay KN1, and the second diode VD21 is connected between the positive electrode of the power supply and the first end of the second relay KL1.

[0073] One end of the first resistor R11 is connected between the first diode VD11 and the first end of the first relay KN1, and the other end is electrically connected to the second end of the first relay KN1 through the first capacitor C11.

[0074] One end of the second resistor R21 is connected between the second diode VD21 and the first end of the second relay KL1, and the other end is electrically connected to the second end of the second relay KL1 through the second capacitor C21.

[0075] The gate G of the MOS transistor Q1 is also electrically connected to the second end (port 2) of the power supply module U1 and the source S of the MOS transistor Q1 through the third resistor R31.

[0076] The gate G of the MOS transistor Q1 is also electrically connected to the third one normally open contact KM131 through the fourth resistor R41.

[0077] Similarly, for the second photovoltaic panel corresponding to the second photovoltaic panel turn-off control device:

[0078] The first end of the first relay KN2 is connected to the positive electrode of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string turn-off controller; the second end of the first relay KN2 is connected to the negative electrode of the power supply, that is, electrically connected to the second end (port 2) of the main control module of the photovoltaic string turn-off controller.

[0079] Meanwhile, the first end of the second relay KL2 is connected to the positive pole of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string cut-off controller; the second end of the second relay KL2 is connected to the negative pole of the power supply, that is, electrically connected to the second end (port 2) of the control module of the photovoltaic string cut-off controller.

[0080] The second end of the first relay KN2 is also electrically connected to the second end of the second relay KL2 through the first normally open contact KN211. The first normally open contact KN211 is also electrically connected to the third end (port 3) of the main control module of the photovoltaic string cut-off controller, and is used to feedback the cut-off state of the photovoltaic panel to the photovoltaic string cut-off controller.

[0081] The drain D of the MOS transistor Q2 is electrically connected to the positive pole of the photovoltaic panel, and the source S is electrically connected to the negative pole of the photovoltaic panel. The drain D of the MOS transistor Q2 is also electrically connected to the first end (port 1) of the power supply module U2 through the first normally open contact KN212 and the first normally closed contact KN213. The source S of the MOS transistor Q2 is electrically connected to the second end (port 2) of the power supply module U2, and the gate G of the MOS transistor Q2 is electrically connected to the third end (port 3) of the power supply module U2 through the third normally open contact KM231.

[0082] One end of the second normally closed contact KL221 is electrically connected to the drain D of the MOS transistor Q2 and the positive pole of the photovoltaic panel, and the other end is electrically connected to the negative pole of the photovoltaic panel, the source S of the MOS transistor Q2, and the second end (port 2) of the power supply module U2.

[0083] The energy storage module, that is, the positive pole of the capacitor C32 is connected between the first normally open contact KN212 and the first normally open contact KN213, and the negative pole is electrically connected to the second end (port 2) of the power supply module U2.

[0084] One end of the third relay KM2 is electrically connected to the second end (port 2) of the power supply module U2, and the other end is electrically connected to the third end (port 3) of the power supply module U2.

[0085] The first diode VD12 is connected between the positive pole of the power supply and the first end of the first relay KN2, and the second diode VD22 is connected between the positive pole of the power supply and the first end of the second relay KL2.

[0086] One end of the first resistor R12 is connected between the first diode VD12 and the first end of the first relay KN2, and the other end is electrically connected to the second end of the first relay KN2 through the first capacitor C12.

[0087] One end of the second resistor R22 is connected between the second diode VD22 and the first end of the second relay KL2, and the other end is electrically connected to the second end of the second relay KL2 through the second capacitor C22.

[0088] The gate G of the MOS transistor Q2 is also electrically connected to the second end (port 2) of the power supply module U2 and the source S of the MOS transistor Q2 through the third resistor R32.

[0089] The gate G of the MOS transistor Q2 is also electrically connected to the first normally open contact KM231 through the fourth resistor R42.

[0090] For the nth photovoltaic panel corresponding nth photovoltaic panel turn-off control device:

[0091] The first end of the first relay KNn is connected to the positive pole of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string turn-off controller; the second end of the first relay KNn is connected to the negative pole of the power supply, that is, electrically connected to the second end (port 2) of the main control module of the photovoltaic string turn-off controller.

[0092] At the same time, the first end of the second relay KLn is connected to the positive pole of the power supply, that is, electrically connected to the first end (port 1) of the main control module of the photovoltaic string turn-off controller; the second end of the second relay KLn is connected to the negative pole of the power supply, that is, electrically connected to the second end (port 2) of the main control module of the photovoltaic string turn-off controller.

[0093] The second end of the first relay KNn is also electrically connected to the second end of the second relay KLn through the first normally open contact KNn11. The first normally open contact KNn11 is also electrically connected to the third end (port 3) of the main control module of the photovoltaic string turn-off controller, and is used to feedback the turn-off state of the photovoltaic panel to the photovoltaic string turn-off controller.

[0094] The drain D of the MOS transistor Qn is electrically connected to the positive pole of the photovoltaic panel, and the source S is electrically connected to the negative pole of the photovoltaic panel. The drain D of the MOS transistor Qn is also electrically connected to the first end (port 1) of the power supply module Un through the first second normally open contact KNn12 and the first third normally closed contact KNn13. The source S of the MOS transistor Qn is electrically connected to the second end of the power supply module Un. The gate G of the MOS transistor Qn is electrically connected to the third end (port 3) of the power supply module Un through the first normally open contact KMn31.

[0095] One end of the second normally closed contact KLn21 is electrically connected to the drain D of the MOS transistor Qn and the positive pole of the photovoltaic panel, and the other end is electrically connected to the negative pole of the photovoltaic panel, the source S of the MOS transistor Qn, and the second end (port 2) of the power supply module Un.

[0096] The positive electrode of the energy storage module, that is, the capacitor C3n, is connected between the first and second normally open contacts KNn12 and the first and third normally open contacts KNn13, and the negative electrode is electrically connected to the second terminal (port 2) of the power supply module Un.

[0097] One end of the third relay KMn is electrically connected to the second terminal (port 2) of the power supply module Un, and the other end is electrically connected to the third terminal (port 3) of the power supply module Un.

[0098] The first diode VD1n is connected between the positive electrode of the power supply and the first end of the first relay KNn, and the second diode VD2n is connected between the positive electrode of the power supply and the first end of the second relay KLn.

[0099] One end of the first resistor R1n is connected between the first diode VD1n and the first end of the first relay KNn, and the other end is electrically connected to the second end of the first relay KNn through the first capacitor C1n.

[0100] One end of the second resistor R2n is connected between the second diode VD2n and the first end of the second relay KLn, and the other end is electrically connected to the second end of the second relay KLn through the second capacitor C2n.

[0101] The gate G of the MOS transistor Qn is also electrically connected to the second terminal (port 2) of the power supply module Un and the source S of the MOS transistor Qn through the third resistor R3n.

[0102] The gate G of the MOS transistor Qn is also electrically connected to the first and third normally open contact KMn31 through the fourth resistor R4n.

[0103] When a fire occurs, the power supply is controlled to turn off multiple series-connected photovoltaic panels in a photovoltaic string. And once an abnormal fire occurs in the photovoltaic panels in the photovoltaic string, the photovoltaic string is turned off by the photovoltaic string shutdown controller, and the photovoltaic panels in the photovoltaic string can be immediately turned off to avoid further expansion of the fire and ensure the safety of photovoltaic power generation.

[0104] In addition, the normally open contact KN111 of the first photovoltaic panel, the normally open contact KN211 of the second photovoltaic panel, ..., and the normally open contact KNn11 of the nth photovoltaic panel in the present utility model are also connected in series to form a series circuit. One end of this series circuit is electrically connected to the negative electrode of the power supply, and the other end is electrically connected to the third terminal (port 3) of the photovoltaic string cut-off controller. When the photovoltaic panel needs to be released from the cut-off state, the power supply is turned on. At this time, due to this series circuit, the first relay KN1 of the first photovoltaic panel is energized. After its normally open contact KN111 is closed, the first relay KN2 of the second photovoltaic panel is then energized, and so on, until the first relay KNn of the nth photovoltaic panel is energized. That is to say, during the process of releasing the cut-off of the photovoltaic panels in the photovoltaic string, the n photovoltaic panels are released from the cut-off state in sequence, which can ensure the safe release of the cut-off of the photovoltaic panels to enter the normal working state.

[0105] The above-mentioned embodiments are only the preferred embodiments of the present utility model and cannot be used to limit the scope of protection of the present utility model. Any non-substantial changes and substitutions made by those skilled in the art based on the present utility model fall within the scope of protection required by the present utility model.

Claims

1. A photovoltaic panel shutdown control device, characterized in that: It includes a static switch, a power module, an energy storage module, a first relay, a second relay and a third relay; wherein the first relay, the second relay and the third relay are all electromagnetic relays, and the first relay is provided with a first normally open contact, a first second normally open contact and a first third normally closed contact; the second relay is provided with a second normally closed contact; the third relay is provided with a third normally open contact; The first end of the first relay is connected to the positive pole of the power supply, and the second end is connected to the negative pole of the power supply; the first end of the second relay is connected to the positive pole of the power supply, and the second end is connected to the negative pole of the power supply; the first end of the third relay is electrically connected to the second end of the power module, and the second end is electrically connected to the third end of the power module; the second end of the first relay is also electrically connected to the second end of the second relay through the first normally open contact; The first end of the static switch is electrically connected to the third end of the power module through the third-first normally open contact, the second end of the static switch is electrically connected to the second end of the power module, and the third end of the static switch is electrically connected to the first end of the power module through the first-second normally open contacts and the first-third normally closed contacts; the third end of the static switch is also electrically connected to the positive pole of the photovoltaic panel in the photovoltaic string, and the second end is also electrically connected to the negative pole of the photovoltaic panel; One end of the second normally closed contact is electrically connected to the positive pole of the photovoltaic panel and the third end of the static switch, and the other end of the second normally closed contact is electrically connected to the negative pole of the photovoltaic panel and the second end of the static switch; the positive pole of the energy storage module is connected between the first two normally open contacts and the first three normally closed contacts, and the negative pole is electrically connected to the second end of the power module; When the photovoltaic panel is turned off, the power supply is disconnected, the first relay loses power, the second relay loses power, then the first and second normally open contacts are opened, the first and third normally closed contacts are closed, the energy storage module is discharged, the power module is powered, the third relay is powered, the third normally open contact is closed, and the static switch is turned on; thereafter, the second and first normally closed contacts are closed, the positive and negative poles of the photovoltaic panel are short-circuited, and the photovoltaic panel is in the off state; and when the energy storage module is discharged, the power module is powered off, the third relay loses power, the third normally open contact is opened, and the static switch is turned off; When the photovoltaic panel is released from shutdown, the power supply is turned on, the first relay is energized, the first normally open contact is closed, the first and second normally open contacts are closed, and the first and third normally closed contacts are opened, then the second relay is energized, the second and first normally closed contacts are opened, the positive and negative electrodes of the photovoltaic panel are released from short circuit, the photovoltaic panel starts to charge the energy storage module, and the photovoltaic panel is in a released shutdown state; The energy storage module is a capacitor C3, the positive electrode of the capacitor C3 is connected between the first and second normally open contacts and the first and third normally closed contacts, and the negative electrode is electrically connected to the second end of the power module to form the energy storage module; The delayed action time of the second relay losing power is greater than the delayed action time of the first relay losing power.

2. The photovoltaic panel shutdown control device according to claim 1, characterized in that: It also includes a first delay circuit and a second delay circuit; wherein the first end of the first relay is also electrically connected to the second end of the first relay through the first delay circuit; the first end of the second relay is also electrically connected to the second end of the second relay through the second delay circuit.

3. The photovoltaic panel shutdown control device according to claim 2, characterized in that: The first delay circuit and the second delay circuit are both RC delay circuits.

4. The photovoltaic panel shutdown control device according to claim 3, characterized in that: The first delay circuit includes a first resistor and a first capacitor, and one end of the first resistor is electrically connected to the first end of the first relay, and the other end of the first resistor is electrically connected to the second end of the first relay through the first capacitor; The second delay circuit includes a second resistor and a second capacitor, and one end of the second resistor is electrically connected to the first end of the second relay, and the other end of the second resistor is electrically connected to the second end of the second relay through the second capacitor.

5. The photovoltaic panel shutdown control device according to claim 1, characterized in that: It also includes a first diode and a second diode; the positive electrode of the first diode is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the first relay; the positive electrode of the second diode is electrically connected to the positive electrode of the power supply, and the negative electrode is electrically connected to the first end of the second relay.

6. The photovoltaic panel shutdown control device according to claim 1, characterized in that: It also includes a third resistor and a fourth resistor; one end of the third resistor is electrically connected to the first end of the static switch, and the other end of the third resistor is electrically connected to the negative pole of the photovoltaic panel and the second end of the static switch; one end of the fourth resistor is electrically connected to the first end of the static switch, and the other end is electrically connected to the third end of the power module through the third normally open contact.

7. The photovoltaic panel shutdown control device according to claim 1, characterized in that: The static switch is a MOS tube, wherein the first end of the static switch is the gate of the MOS tube, the second end of the static switch is the source of the MOS tube, and the third end of the static switch is the drain of the MOS tube.

8. The photovoltaic panel shutdown control device according to claim 1, characterized in that: The first normally open contact is also electrically connected to the photovoltaic string shutdown controller, so that the photovoltaic string shutdown controller determines whether the photovoltaic panel is in the shutdown state according to the first normally open contact.

9. A photovoltaic string shutdown control system, comprising a plurality of photovoltaic strings connected in parallel; wherein: Each photovoltaic string includes a plurality of photovoltaic panels connected in series; it is characterized in that it also includes a photovoltaic panel shutdown control device as described in any one of claims 1-8; wherein each photovoltaic panel is provided with a corresponding photovoltaic panel shutdown control device.

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