High voltage dc circuit breaker

Abstract

The utility model discloses a kind of high-voltage direct-current cut-off devices.The high-voltage direct-current cut-off device includes mechanical switch and power electronic switch;Mechanical switch includes mechanical switch key, permanent magnet, first electromagnet, first switch, second electromagnet and second switch;The third end of mechanical switch key is linked with permanent magnet, the third end of mechanical switch key is used to connect the first end and second end of mechanical switch key when first switch is turned on, disconnect the first end and second end of mechanical switch key when second switch is turned on;Power electronic switch is used to be turned on or be turned off according to third control signal, the on time of power electronic switch is ahead of the on time of first switch, the off time of power electronic switch is behind the off time of second switch.Improves the reliability of mechanical switch action.Simultaneously reduce the power consumption of high-voltage direct-current cut-off device.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic power generation technology, and in particular to a high-voltage DC shutdown device. Background Technology

[0002] In photovoltaic (PV) power generation systems, bypass diodes are installed on the back of the PV panels. When a PV panel fails, the main string current flows through the bypass diodes. At this time, a shutdown device can be installed between the PV panel series branch and the inverter to reduce the risk of fire caused by overheating from the long-term flow of current through the bypass diodes. This also avoids the need for a separate fast shutdown device on each PV panel in the series branch, reducing the cost of the PV system. However, in existing technologies, the shutdown devices between the PV panel series branch and the inverter suffer from arcing or high power consumption, failing to meet the requirements of PV power generation systems. Utility Model Content

[0003] This invention provides a high-voltage DC shutdown device to improve the performance of high-voltage DC shutdown devices, solve the problems of arcing and power consumption of high-voltage DC shutdown devices, and reduce the cost of photovoltaic power generation systems.

[0004] This utility model provides a high-voltage DC shutdown device for controlling the conduction state between an inverter and a photovoltaic panel series branch; the high-voltage DC shutdown device includes a mechanical switch and a power electronic switch;

[0005] The mechanical switch includes a mechanical on / off switch, a permanent magnet, a first electromagnet, a first switch, a second electromagnet, and a second switch; both the first and second electromagnets are magnetically coupled to the permanent magnet; the first switch and the first electromagnet are connected in series between a first power supply terminal and a second power supply terminal, and the second switch and the second electromagnet are connected in series between the first power supply terminal and the second power supply terminal; the first switch is used to turn on or off according to a first control signal, and the second switch is used to turn on or off according to a second control signal; the magnetism of the first electromagnet when energized is opposite to that of the permanent magnet, and the magnetism of the second electromagnet when energized is the same as that of the permanent magnet; the mechanical switch The first end of the key and the first end of the power electronic switch are connected to the input end of the inverter. The second end of the mechanical key and the second end of the power electronic switch are connected to the output end of the photovoltaic panel series branch. The third end of the mechanical key is linked to the permanent magnet. The third end of the mechanical key is used to connect the first and second ends of the mechanical key when the first switch is turned on, and to disconnect the first and second ends of the mechanical key when the second switch is turned on. The power electronic switch is used to turn on or off according to a third control signal. The turn-on time of the power electronic switch precedes the turn-on time of the first switch, and the turn-off time of the power electronic switch lags behind the turn-off time of the second switch.

[0006] Optionally, the first switch includes a first controllable switching transistor, and the second switch includes a second controllable switching transistor;

[0007] The first end of the first controllable switch and the first end of the second controllable switch are both connected to the first power supply terminal. The second end of the first controllable switch is connected to the first end of the first electromagnet, and the second end of the second controllable switch is connected to the first end of the second electromagnet. The second ends of the first electromagnet and the second electromagnet are both connected to the second power supply terminal. The control terminal of the first controllable switch is used to input the first control signal, and the control terminal of the second controllable switch is used to input the second control signal.

[0008] Optionally, the first electromagnet includes a first coil and a first iron core; the second electromagnet includes a second coil and a second iron core.

[0009] The first end of the first coil is connected to the second end of the first controllable switch tube, and the second ends of the first coil and the second coil are both connected to the second power supply terminal. The first end of the second coil is connected to the second end of the second controllable switch tube. The first iron core and the second iron core are integrally formed.

[0010] Optionally, the high-voltage DC shutdown device also includes a first diode and a second diode;

[0011] The anode of the first diode is connected to the first end of the first coil, and the cathode of the first diode is connected to the second end of the first coil; the anode of the second diode is connected to the first end of the second coil, and the cathode of the second diode is connected to the second end of the second coil.

[0012] Optionally, the high-voltage DC shutdown device also includes a third diode and a first capacitor;

[0013] The anode of the third diode is connected to the second power supply terminal, the cathode of the third diode and the first terminal of the first capacitor are connected to the second terminal of the first coil and the second terminal of the second coil, and the second terminal of the first capacitor is connected to the first power supply terminal.

[0014] Optionally, the power electronic switch includes a photovoltaic optocoupler and a third controllable switching transistor;

[0015] The first terminal of the third controllable switch is connected to the input terminal of the inverter, the second terminal of the third controllable switch is connected to the output terminal of the photovoltaic panel series branch, the control terminal of the third controllable switch is connected to the output terminal of the photovoltaic optocoupler, the first input terminal of the photovoltaic optocoupler is used to input the first voltage, and the second input terminal of the photovoltaic optocoupler is used to input the third control signal.

[0016] Optionally, the power electronic switch further includes a first resistor and a second capacitor;

[0017] The first resistor and the second capacitor are connected in series and then connected in parallel between the first and second terminals of the third controllable switch.

[0018] Optionally, the power electronic switch further includes a transient voltage suppression diode; the transient voltage suppression diode is connected in parallel between the first terminal and the second terminal of the third controllable switch.

[0019] Optionally, the high-voltage DC shutdown device further includes a power supply module, the input terminal of which is connected to the output terminal of the inverter, the first output terminal of which serves as the second power supply terminal, and the second output terminal of which is connected to the first input terminal of the photovoltaic optocoupler; the power supply module is used to perform voltage transformation on the voltage provided by the inverter to form the first voltage and the second voltage provided by the second power supply terminal.

[0020] Optionally, the high-voltage DC shutdown device also includes a voltage monitoring module and a control module;

[0021] The input terminal of the voltage monitoring module is connected to the output terminal of the inverter, and the output terminal of the voltage monitoring module is connected to the control module. The voltage monitoring module is used to monitor the voltage provided by the inverter and generate a monitoring voltage. The control module is used to provide the first control signal, the second control signal, and the third control signal according to the monitoring voltage.

[0022] The technical solution of this utility model embodiment, by setting a high-voltage DC shutdown device connected between the positive input terminal of the inverter and the positive output terminal of the photovoltaic panel series branch, can reduce the number of shutdown devices required in the photovoltaic power generation system and lower the cost of the photovoltaic power generation system. The high-voltage DC shutdown device includes a mechanical switch and a power electronic switch. The mechanical switch includes a mechanical on / off switch, a permanent magnet, a first electromagnet, a first switch, a second electromagnet, and a second switch. During the connection process of the high-voltage DC shutdown device, the power electronic switch can be controlled to connect first, and then the mechanical switch can be controlled to connect. During the disconnection process of the high-voltage DC shutdown device, the mechanical switch can be controlled to disconnect first, and then the power electronic switch can be controlled to disconnect. This allows the power electronic switch to maintain the connection state of the high-voltage DC shutdown device when the mechanical switch is activated, thereby avoiding the bouncing and arcing phenomenon when the mechanical switch is activated, and improving the reliability of the mechanical switch operation. Simultaneously, in the maintenance state of the high-voltage DC shutdown device, the permanent magnet can maintain the state of the mechanical switch, which can reduce the conduction loss of the high-voltage DC shutdown device and reduce its power consumption. Attached Figure Description

[0023] Figure 1 A schematic diagram of a photovoltaic power generation system provided in an embodiment of this utility model;

[0024] Figure 2 A schematic diagram of the structure of a mechanical switch provided by this utility model;

[0025] Figure 3 A schematic diagram of the structure of a power electronic switch provided by this utility model;

[0026] Figure 4 A schematic diagram of the structure of a partial high-voltage DC shutdown device provided in this embodiment of the present invention;

[0027] Figure 5 A schematic diagram of another partial high-voltage DC shutdown device provided by this utility model. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0029] Figure 1 This is a schematic diagram of the structure of a photovoltaic power generation system provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a mechanical switch provided by this utility model. Figure 1 and Figure 2 As shown, the high-voltage DC shut-off device 10 is used to control the conduction state between the inverter 20 and the photovoltaic panel series branch 30. The high-voltage DC shut-off device 10 includes a mechanical switch 110 and a power electronic switch 120. The mechanical switch 110 includes a mechanical on / off switch K1, a permanent magnet S1, a first electromagnet T1, a first switch M1, a second electromagnet S2, and a second switch M2. Both the first electromagnet T1 and the second electromagnet T2 are magnetically coupled to the permanent magnet S1. The first switch M1 is connected in series with the first electromagnet T1 between the first power supply terminal V1 and the second power supply terminal V2, and the second switch M2 is connected in series with the second electromagnet T2 between the first power supply terminal V1 and the second power supply terminal V2. The first switch M1 is used to turn on or off according to a first control signal ctrl1, and the second switch M2 is used to turn on or off according to a second control signal ctrl2. The magnetism of the first electromagnet T1 when powered on is related to that of the permanent magnet S1. The magnetism of S1 is opposite, and the magnetism of the second electromagnet T2 when energized is the same as that of the permanent magnet S1; the first end of the mechanical switch K1 and the first end of the power electronic switch 120 are connected to the input terminal IN of the inverter 20, the second end of the mechanical switch K1 and the second end of the power electronic switch 120 are connected to the output terminal OUT of the photovoltaic panel series branch 30, and the third end of the mechanical switch K1 is linked with the permanent magnet S1. The third end of the mechanical switch K1 is used to connect the first and second ends of the mechanical switch K1 when the first switch M1 is turned on, and to disconnect the first and second ends of the mechanical switch K1 when the second switch M2 is turned on; the power electronic switch 120 is used to turn on or off according to the third control signal ctrl3. The turn-on time of the power electronic switch 120 is ahead of the turn-on time of the first switch M1, and the turn-off time of the power electronic switch 120 is behind the turn-off time of the second switch M2.

[0030] Specifically, the photovoltaic panel series branch 30 includes multiple photovoltaic panels 31 connected in series, and the output terminal of the first photovoltaic panel 31 or the highest photovoltaic panel 31 of the photovoltaic panel series branch 30 is designated as the output terminal OUT of the photovoltaic panel series branch 30 for outputting the electrical energy provided by the photovoltaic panel series branch 30. The electrical energy output after the multiple photovoltaic panels 31 are connected in series is high-voltage direct current. For example, as shown... Figure 1As shown, the photovoltaic panel series branch 30 includes a positive output terminal OUT+ and a negative output terminal OUT-. The inverter 20's input terminal IN also includes a positive input terminal IN+ and a negative input terminal IN-. The positive input terminal IN+ of the inverter 20 is connected to the positive output terminal OUT+ of the photovoltaic panel series branch 30, and the negative input terminal IN- of the inverter 20 is connected to the negative output terminal OUT- of the photovoltaic panel series branch 30, thus enabling the output of electrical energy provided by the photovoltaic panel series branch 30 to the inverter 20. The inverter 20 inverts the electrical energy provided by the photovoltaic panel series branch 30, enabling the photovoltaic panel series branch 30 to connect to the power grid and / or supply power to AC loads. A high-voltage DC shutdown device 10 is connected between the positive input terminal IN+ of the inverter 20 and the positive output terminal OUT+ of the photovoltaic panel series branch 30, used to control the conduction or shutdown between the inverter 20 and the photovoltaic panel series branch 30. This reduces the number of shutdown devices required in the photovoltaic power generation system, lowering the system's cost.

[0031] The high-voltage DC shut-off device 10 includes a mechanical switch 110 and a power electronic switch 120. A first switch M1 in the mechanical switch 110 is connected in series with a first electromagnet T1 between a first power supply terminal V1 and a second power supply terminal V2. When the first switch M1 is turned on according to a first control signal ctrl1, the branch containing the first electromagnet T1 forms a loop, energizing the first electromagnet T1. For example, the first power supply terminal V1 can be a ground terminal (GND), and the second power supply terminal V2 can be a positive voltage terminal. The magnetism generated by the first electromagnet T1 is opposite to the magnetism of the permanent magnet S1, generating an attractive force on the permanent magnet S1. Simultaneously, the mechanical switch K1 is linked to the permanent magnet S1. The mechanical switch K1 is located on the side of the permanent magnet S1 away from the first electromagnet T1, and the third end of the mechanical switch K1 is opposite to the first and second ends of the mechanical switch K1. When the first electromagnet T1 exerts an attractive force on the permanent magnet S1, the permanent magnet S1, in conjunction with the movement of the third end of the mechanical switch K1, allows the third end of the mechanical switch K1 to simultaneously contact and connect with the first and second ends of the mechanical switch K1. This establishes the connection between the first and second ends of the mechanical switch K1, enabling the inverter 20's input terminal IN to connect with the photovoltaic panel series branch 30's output terminal OUT. After the mechanical switch K1 is connected, the first switch M1 can be turned off according to the first control signal ctrl1, de-energizing the first electromagnet T1. The permanent magnet S1 can maintain the connected state of the mechanical switch K1, reducing the power consumption of the high-voltage DC shutdown device 10.

[0032] The second switch M2 and the second electromagnet T2 are connected in series between the first power supply terminal V1 and the second power supply terminal V2. When the second switch M2 is turned on according to the second control signal ctrl2, the branch containing the second electromagnet T2 forms a loop, energizing the second electromagnet T2. The magnetism generated by the second electromagnet T2 is the same as that of the permanent magnet S1, generating a repulsive force on the permanent magnet S1. The permanent magnet S1 moves the third end of the mechanical switch K1, causing the third end of the mechanical switch K1 to disconnect from both the first and second ends of the mechanical switch K1. This disconnects the first and second ends of the mechanical switch K1, turning it off and disconnecting the input terminal IN of the inverter 20 from the output terminal OUT of the photovoltaic panel series branch 30. After the mechanical switch K1 is turned off, the second switch M2 can be turned off according to the second control signal ctrl2, de-energizing the second electromagnet T2. The permanent magnet S1 can maintain the off state of the mechanical switch K1, reducing the power consumption of the high-voltage DC shutdown device 10.

[0033] During the operation of the high-voltage DC shutdown switch 10, when the high-voltage DC shutdown switch 10 changes from the off state to the on state, the conduction time of the power electronic switch 120 precedes the conduction time of the first switch M1. Therefore, the power electronic switch 120 first conducts according to the third control signal ctrl3, connecting the input terminal IN of the inverter 20 and the output terminal OUT of the photovoltaic panel series branch 30 through the power electronic switch 120. Then, the first switch M1 conducts, causing the first electromagnet T1 to attract the permanent magnet S1, which in turn moves the third terminal of the mechanical switch K1, connecting the mechanical switch K1. This avoids the bouncing and arcing phenomenon when the mechanical switch K1 is turned on, improving the reliability of the mechanical switch K1's operation. Then, the power electronic switch 120 turns off according to the third control signal ctrl3, maintaining the connection between the input terminal IN of the inverter 20 and the output terminal OUT of the photovoltaic panel series branch 30. At this time, the mechanical switch K1 is kept connected by the magnetism of the permanent magnet S1, thereby reducing the conduction loss of the high-voltage DC shut-off device 10 and its power consumption. When the high-voltage DC shut-off device 10 changes from the on state to the off state, the off time of the power electronic switch 120 lags behind the off time of the second switch M2. Therefore, the power electronic switch 120 is first kept in the on state according to the third control signal ctrl3, and then the second switch M2 is turned on, causing the second permanent magnet T2 to be energized, repelling the permanent magnet S1, and driving the third end of the mechanical switch K1 to move, thus turning off the mechanical switch K1. At this time, the input terminal IN of the inverter 20 and the output terminal OUT of the photovoltaic panel series branch 30 can still be kept connected by the power electronic switch 120, avoiding arcing when the mechanical switch K1 is turned off and improving the reliability of the mechanical switch K1's operation. Then, the power electronic switch 120 is turned off according to the third control signal ctrl3, thus realizing the turn-off of the high voltage DC shutdown device 10.

[0034] The technical solution of this embodiment, by connecting a high-voltage DC shutdown device (HVDC) between the positive input terminal of the inverter and the positive output terminal of the photovoltaic panel series branch, can reduce the number of shutdown devices required in the photovoltaic power generation system and lower the cost of the photovoltaic power generation system. The HVDC shutdown device includes a mechanical switch and a power electronic switch. The mechanical switch includes a mechanical on / off switch, a permanent magnet, a first electromagnet, a first switch, a second electromagnet, and a second switch. During the HVDC shutdown process, the power electronic switch can be controlled to connect first, followed by the mechanical switch. During the HVDC shutdown process, the mechanical switch can be controlled to turn off first, followed by the power electronic switch. This allows the power electronic switch to maintain the connection state of the HVDC shutdown device when the mechanical switch operates, thereby avoiding the bouncing and arcing phenomenon during mechanical switch operation and improving the reliability of the mechanical switch operation. Simultaneously, during the maintenance state of the HVDC shutdown device, the permanent magnet can maintain the state of the mechanical switch, reducing the conduction loss of the HVDC shutdown device and thus reducing its power consumption.

[0035] Continue to refer to Figure 2 The first switch M1 includes a first controllable switch transistor Q1, and the second switch M2 includes a second controllable switch transistor Q2. The first end of the first controllable switch transistor Q1 and the first end of the second controllable switch transistor Q2 are both connected to the first power supply terminal V1. The second end of the first controllable switch transistor Q1 is connected to the first end of the first electromagnet T1, and the second end of the second controllable switch transistor Q2 is connected to the first end of the second electromagnet T2. The second ends of the first electromagnet T1 and the second electromagnet T2 are both connected to the second power supply terminal V2. The control terminal of the first controllable switch transistor Q1 is used to input the first control signal ctrl1, and the control terminal of the second controllable switch transistor Q2 is used to input the second control signal ctrl2.

[0036] Specifically, the first controllable switch Q1 and the second controllable switch Q2 can be transistors, such as metal-oxide-semiconductor field-effect transistors or triodes. Figure 2 The example illustrates that both the first controllable switch Q1 and the second controllable switch Q2 are N-type transistors. The first control signal ctrl1 and the second control signal ctrl2 can be pulse signals. When the first control signal ctrl1 outputs a high-level pulse signal, the first controllable switch Q1 is turned on, energizing the first electromagnet T1. When the first control signal ctrl1 outputs a low-level pulse signal, the first controllable switch Q1 is turned off, de-energizing the first electromagnet T1. Similarly, when the second control signal ctrl2 outputs a high-level pulse signal, the second controllable switch Q2 is turned on, energizing the second electromagnet T2. When the second control signal ctrl2 outputs a low-level pulse signal, the second controllable switch Q2 is turned off, de-energizing the second electromagnet T2.

[0037] Continue to refer to Figure 2 The first switch M1 also includes a first protective resistor Rt1, used to discharge static electricity from the first controllable switch Q1, preventing excessive voltage across the equivalent capacitance between the control terminal and the first terminal of the first controllable switch Q1 due to static electricity accumulation, thereby reducing the probability of malfunction or breakdown of the first controllable switch Q1. The second switch M2 also includes a second protective resistor Rt2, used to discharge static electricity from the second controllable switch Q2, preventing excessive voltage across the equivalent capacitance between the control terminal and the first terminal of the second controllable switch Q2 due to static electricity accumulation, thereby reducing the probability of malfunction or breakdown of the second controllable switch Q2.

[0038] Continue to refer to Figure 2 The first electromagnet T1 includes a first coil L1 and a first iron core TL1; the second electromagnet T2 includes a second coil L2 and a second iron core TL2; the first end of the first coil L1 is connected to the second end of the first controllable switch Q1, the second end of the first coil L1 and the second end of the second coil L2 are both connected to the second power supply terminal V2, and the first end of the second coil L2 is connected to the second end of the second controllable switch Q2; the first iron core TL1 and the second iron core TL2 are integrally formed.

[0039] Specifically, such as Figure 2 As shown, the first iron core TL1 and the second iron core TL2 are integrally formed, that is, the first iron core TL1 and the second iron core TL2 are different parts of the same iron core, which can simplify the structure of the mechanical switch 110. At this time, the iron core part wound by the first coil L1 is called the first iron core TL1, and the iron core part wound by the second coil L2 is called the second iron core TL2.

[0040] Continue to refer to Figure 2 The high-voltage DC shut-off device 10 also includes a first diode D1 and a second diode D2; the anode of the first diode D1 is connected to the first end of the first coil L1, and the cathode of the first diode D1 is connected to the second end of the first coil L1; the anode of the second diode D2 is connected to the first end of the second coil L2, and the cathode of the second diode D2 is connected to the second end of the second coil L2.

[0041] Specifically, the first diode D1 is connected in parallel with the first coil L1. When the first coil L1 is de-energized, it can discharge through the first diode D1. Similarly, the second diode D2 is connected in parallel with the second coil L2. When the second coil L2 is de-energized, it can discharge through the second diode D2.

[0042] Continue to refer to Figure 2The high-voltage DC shut-off device 10 also includes a third diode D3 and a first capacitor C1; the anode of the third diode D3 is connected to the second power supply terminal V2, the cathode of the third diode D3 and the first terminal of the first capacitor C1 are connected to the second terminal of the first coil L1 and the second terminal of the second coil L2, and the second terminal of the first capacitor C1 is connected to the first power supply terminal V1.

[0043] Specifically, the first capacitor C1 has an energy storage function. When the power supply to the high-voltage DC shutdown device 10 is interrupted, the first capacitor C1 can act as a power source to supply power to the first coil L1 and the second coil L2, improving the reliability of the high-voltage DC shutdown device 10. At the same time, the cathode of the third diode D3 is connected to the first terminal of the first capacitor C1, so that when the first capacitor C1 supplies power to the first coil L1 and the second coil L2, it prevents electrical energy from being transferred to the second power supply terminal V2, thereby preventing the electrical energy of the first capacitor C1 from flowing back to the second power supply terminal V2.

[0044] Figure 3 This is a schematic diagram of the structure of a power electronic switch provided by this utility model, as shown below. Figure 3 As shown, the power electronic switch 120 includes a photovoltaic optocoupler U1 and a third controllable switch Q3; the first terminal of the third controllable switch Q3 is connected to the input terminal IN of the inverter 20, the second terminal of the third controllable switch Q3 is connected to the output terminal OUT of the photovoltaic panel series branch 30, and the control terminal of the third controllable switch Q3 is connected to the output terminal of the photovoltaic optocoupler U1. The first input terminal of the photovoltaic optocoupler U1 is used to input a first voltage v1, and the second input terminal of the photovoltaic optocoupler U1 is used to input a third control signal ctrl3.

[0045] Specifically, the third control signal ctrl3 can be provided by the control module of the high-voltage DC shutdown unit 10. When the control module outputs the third control signal ctrl3, the potential of the third control signal ctrl3 and the first voltage v1 provide a voltage difference for the photovoltaic optocoupler U1, causing the photodiode at the emitting end of the photovoltaic optocoupler U1 to emit light. The receiving end of the photovoltaic optocoupler U1 generates electrical energy based on the light, providing a control signal to the control terminal of the third controllable switch Q3 to control the conduction or turn-off of the third controllable switch Q3. For example, the first voltage v1 can be a positive voltage, such as 3.3V. The third controllable switch Q3 is an N-type transistor. When controlling the third controllable switch Q3 to conduct, the third control signal ctrl3 can be at a low level, causing the photodiode of the photovoltaic optocoupler U1 to emit light. The photovoltaic optocoupler U1 outputs a high-level control signal to the control terminal of the third controllable switch Q3 based on the light emitted by the photodiode, causing the third controllable switch Q3 to conduct.

[0046] It should be noted that continued reference is necessary. Figure 2The power electronic switch 120 also includes a third protection resistor Rt3, connected between the control terminal and the second terminal of the third controllable switch Q3, used to discharge static electricity from the third controllable switch Q3, preventing excessive voltage across the equivalent capacitance between the control terminal and the first terminal of the third controllable switch Q3 due to static electricity accumulation, thus reducing the probability of malfunction or breakdown of the third controllable switch Q3. The power electronic switch 120 also includes a fourth protection resistor Rt4, connected to the first input terminal of the photovoltaic optocoupler U1, which can limit the current at the input terminal of the photovoltaic optocoupler U1.

[0047] Continue to refer to Figure 2 The power electronic switch 120 also includes a first resistor R1 and a second capacitor C2; the first resistor R1 and the second capacitor C2 are connected in series and then connected in parallel between the first and second terminals of the third controllable switch Q3.

[0048] Specifically, the first resistor R1 and the second capacitor C2 are connected in series and then connected in parallel between the first and second terminals of the third controllable switch Q3. This can absorb the power surge between the input terminal IN of the inverter 20 and the output terminal OUT of the photovoltaic panel series branch 30, thereby protecting the third controllable switch Q3.

[0049] Continue to refer to Figure 2 The power electronic switch 120 also includes a transient voltage suppression diode RV1; the transient voltage suppression diode RV1 is connected in parallel between the first and second terminals of the third controllable switch Q3, which can reduce the probability of the third controllable switch Q3 breaking down.

[0050] Figure 4 This is a schematic diagram of a partial high-voltage DC shutdown device provided as an embodiment of the present invention. Figure 1 and Figure 4 As shown, the high-voltage DC shutdown device 10 also includes a power supply module 130. The input terminal of the power supply module 130 is connected to the output terminal of the inverter 20. The first output terminal of the power supply module 130 serves as the second power supply terminal V2. The second output terminal of the power supply module 130 is connected to the first input terminal of the photovoltaic optocoupler U1. The power supply module 130 is used to perform voltage transformation on the voltage provided by the inverter 20 to form a first voltage v1 and a second voltage provided by the second power supply terminal V2.

[0051] Specifically, the output terminals of inverter 20 may include a positive output terminal J1 and a negative output terminal J2, which can provide a DC voltage, such as 12V or 24V. Power module 130 includes a fourth diode D4 and a voltage conversion circuit U2. The anode of the fourth diode D4 is connected to the positive output terminal J1 of inverter 20, and the negative output terminal J2 of inverter 20 is grounded to GND. The cathode of the fourth diode D4 serves as the first output terminal of power module 130. The voltage provided by inverter 20, after passing through the fourth diode D4, serves as the second voltage provided by the second power supply terminal V2, used to power the coil in mechanical switch 110. The input terminal of voltage conversion circuit U2 is connected to the cathode of the fourth diode D4, and the output terminal of voltage conversion circuit U2 serves as the second output terminal of power module 130. The power supply terminal of voltage conversion circuit U2 is grounded to GND. Voltage conversion circuit U2 converts the second voltage into a first voltage V1, used to power photovoltaic optocoupler U1. Simultaneously, the fourth diode D4 prevents current from flowing back to the positive output terminal J1 of inverter 20.

[0052] Continue to refer to Figure 4 The power module 130 also includes a third capacitor C3 and a fourth capacitor C4. The third capacitor C3 is connected between the first output terminal of the power module 130 and ground GND, and is used to filter the second voltage output by the power module 130. The fourth capacitor C4 is connected between the second output terminal of the power module 130 and ground GND, and is used to filter the first voltage v1 output by the power module 130.

[0053] Figure 5 A schematic diagram of another partial high-voltage DC shutdown device provided by this utility model. (See attached diagram.) Figure 1 , Figure 4 and Figure 5 As shown, the high-voltage DC shutdown unit 10 also includes a voltage monitoring module 140 and a control module 150; the input terminal of the voltage monitoring module 140 is connected to the output terminal of the inverter 20, and the output terminal of the voltage monitoring module 140 is connected to the control module 150. The voltage monitoring module 140 is used to monitor the voltage provided by the inverter 20 and form a monitoring voltage v2; the control module 150 is used to provide a first control signal ctrl1, a second control signal ctrl2 and a third control signal ctrl3 according to the monitoring voltage v2.

[0054] Specifically, the voltage monitoring module 140 monitors the voltage provided by the inverter 20 and generates a monitored voltage v2, which is output to the input terminal PA3 of the control module 150. The control module 150 determines the voltage provided by the inverter 20 based on the monitored voltage v2, and further determines the voltage provided by the photovoltaic panel series branch 30. Then, the control module 150 determines whether the high-voltage DC shutdown switch 10 needs to be disconnected based on the determination result. Thus, when the high-voltage DC shutdown switch 10 needs to be closed, it outputs a first control signal ctrl1 and a third control signal ctrl3. The first control signal ctrl1 is output to the control terminal of the first controllable switch Q1 through the first output terminal PA1 of the control module 150, and the third control signal ctrl3 is output to the second input terminal of the photovoltaic optocoupler U1 through the third output terminal PA0 of the control module 150. This causes the power electronic switch 120 to turn on first according to the third control signal ctrl3, and then the mechanical switch 110 to turn on according to the first control signal ctrl1. After the mechanical switch 110 is turned on, the output of the third control signal ctrl3 stops, and the power electronic switch 120 turns off, allowing the mechanical switch 110 to remain on according to the permanent magnet S1. When it is necessary to disconnect the high-voltage DC shut-off device 10, the second control signal ctrl2 and the third control signal ctrl3 are output. The second control signal ctrl2 is output to the control terminal of the second controllable switch Q2 through the second output terminal PA2 of the control module 150, so that the power electronic switch 120 first turns on according to the third control signal ctrl3, then the mechanical switch 110 turns off according to the second control signal ctrl2, and then the power electronic switch 120 turns off according to the third control signal ctrl3. This allows the power electronic switch 120 to maintain the connection state of the high-voltage DC shut-off device 10 when the mechanical switch 110 is activated, thereby avoiding the bouncing and arcing phenomenon when the mechanical switch 110 is activated, and improving the reliability of the mechanical switch 110. Meanwhile, in the maintenance state of the high voltage DC shut-off switch 10, the state of the mechanical switch 110 can be maintained by the permanent magnet S1, which can reduce the conduction loss of the high voltage DC shut-off switch 10 and reduce the power consumption of the high voltage DC shut-off switch 10.

[0055] For example, the voltage monitoring module 140 includes a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth capacitor C5. The second resistor R2 and the third resistor R3 are connected in series between the positive output terminal J1 of the inverter 20 and ground GND, used to divide the voltage provided by the inverter 20. The first end of the fourth resistor R4 is connected to the connection point of the second resistor R2 and the third resistor R3, and the second end of the fourth resistor R4 is connected to the first terminal of the fifth capacitor C5 and connected to the control module 150. The second terminal of the fifth capacitor C5 is grounded to GND, allowing the fourth resistor R4 and the fifth capacitor C5 to filter the divided voltage.

[0056] Continue to refer to Figure 4 The voltage monitoring module 140 also includes a fifth diode D5. The anode of the fifth diode D5 is connected to the positive output terminal J1 of the inverter 20, and the cathode of the fifth diode D5 is connected to the first end of the second resistor R2 to prevent current from flowing back to the positive output terminal J1 of the inverter 20.

[0057] It should be noted that the second output terminal of the power module 130 is also connected to the power supply terminal VDD of the control module 150 to supply power to the control module 150.

[0058] Continue to refer to Figure 5 The high-voltage DC shutdown device 10 also includes a reset circuit 160. The first voltage terminal V3 of the reset circuit 160 is connected to the second output terminal of the power supply module 130, and the second voltage terminal V4 of the reset circuit 160 is grounded to GND. The reset module 160 includes a fifth resistor R5 and a sixth capacitor C6 connected in series between the first voltage terminal V3 and the second power supply terminal V4. The connection node between the fifth resistor R5 and the sixth capacitor C6 is connected to the reset terminal REST of the control module 150, which is used to reset the control module 150 after the power supply module 130 is powered.

[0059] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A high-voltage DC shut-off device, characterized in that, Used to control the conduction state between the inverter (20) and the photovoltaic panel series branch (30); the high voltage DC shut-off device (10) includes a mechanical switch (110) and a power electronic switch (120). The mechanical switch (110) includes a mechanical on / off switch (K1), a permanent magnet (S1), a first electromagnet (T1), a first switch (M1), a second electromagnet (T2), and a second switch (M2). Both the first electromagnet (T1) and the second electromagnet (T2) are magnetically coupled to the permanent magnet (S1). The first switch (M1) and the first electromagnet (T1) are connected in series between a first power supply terminal (V1) and a second power supply terminal (V2), and the second switch (M2) and the second electromagnet (T2) are connected in series between the first power supply terminal (V1) and the second power supply terminal (V2). The first switch (M1) is used to turn on or off according to a first control signal (ctrl1), and the second switch (M2) is used to turn on or off according to a second control signal (ctrl2). The magnetism of the first electromagnet (T1) when energized is opposite to that of the permanent magnet (S1), and the magnetism of the second electromagnet (T2) when energized is opposite to that of the permanent magnet (S1). The same applies; the first end of the mechanical switch (K1) and the first end of the power electronic switch (120) are connected to the input terminal (IN) of the inverter (20), the second end of the mechanical switch (K1) and the second end of the power electronic switch (120) are connected to the output terminal (OUT) of the photovoltaic panel series branch (30), the third end of the mechanical switch (K1) is linked with the permanent magnet (S1), the third end of the mechanical switch (K1) is used to connect the first end and the second end of the mechanical switch (K1) when the first switch (M1) is turned on, and to disconnect the first end and the second end of the mechanical switch (K1) when the second switch (M2) is turned on; the power electronic switch (120) is used to turn on or off according to the third control signal (ctrl3), the turn-on time of the power electronic switch (120) is ahead of the turn-on time of the first switch (M1), and the turn-off time of the power electronic switch (120) is behind the turn-off time of the second switch (M2).

2. The high-voltage DC shutdown device according to claim 1, characterized in that, The first switch (M1) includes a first controllable switch (Q1), and the second switch (M2) includes a second controllable switch (Q2). The first terminal of the first controllable switch (Q1) and the first terminal of the second controllable switch (Q2) are both connected to the first power supply terminal (V1). The second terminal of the first controllable switch (Q1) is connected to the first terminal of the first electromagnet (T1). The second terminal of the second controllable switch (Q2) is connected to the first terminal of the second electromagnet (T2). The second terminals of the first electromagnet (T1) and the second electromagnet (T2) are both connected to the second power supply terminal (V2). The control terminal of the first controllable switch (Q1) is used to input the first control signal (ctrl1), and the control terminal of the second controllable switch (Q2) is used to input the second control signal (ctrl2).

3. The high-voltage DC shutdown device according to claim 2, characterized in that, The first electromagnet (T1) includes a first coil (L1) and a first iron core (TL1); the second electromagnet (T2) includes a second coil (L2) and a second iron core (TL2). The first end of the first coil (L1) is connected to the second end of the first controllable switch (Q1), the second end of the first coil (L1) and the second end of the second coil (L2) are both connected to the second power supply terminal (V2), the first end of the second coil (L2) is connected to the second end of the second controllable switch (Q2); the first iron core (TL1) and the second iron core (TL2) are integrally formed.

4. The high-voltage DC shutdown device according to claim 3, characterized in that, It also includes a first diode (D1) and a second diode (D2); The anode of the first diode (D1) is connected to the first end of the first coil (L1), and the cathode of the first diode (D1) is connected to the second end of the first coil (L1); the anode of the second diode (D2) is connected to the first end of the second coil (L2), and the cathode of the second diode (D2) is connected to the second end of the second coil (L2).

5. The high-voltage DC shutdown device according to claim 3, characterized in that, It also includes a third diode (D3) and a first capacitor (C1); The anode of the third diode (D3) is connected to the second power supply terminal (V2), the cathode of the third diode (D3) and the first terminal of the first capacitor (C1) are connected to the second terminal of the first coil (L1) and the second terminal of the second coil (L2), and the second terminal of the first capacitor (C1) is connected to the first power supply terminal (V1).

6. The high-voltage DC shutdown device according to any one of claims 1-5, characterized in that, The power electronic switch (120) includes a photovoltaic optocoupler (U1) and a third controllable switching transistor (Q3). The first terminal of the third controllable switch (Q3) is connected to the input terminal (IN) of the inverter (20), the second terminal of the third controllable switch (Q3) is connected to the output terminal (OUT) of the photovoltaic panel series branch (30), the control terminal of the third controllable switch (Q3) is connected to the output terminal of the photovoltaic optocoupler (U1), the first input terminal of the photovoltaic optocoupler (U1) is used to input the first voltage (v1), and the second input terminal of the photovoltaic optocoupler (U1) is used to input the third control signal (ctrl3).

7. The high-voltage DC shutdown device according to claim 6, characterized in that, The power electronic switch (120) also includes a first resistor (R1) and a second capacitor (C2); The first resistor (R1) and the second capacitor (C2) are connected in series and then connected in parallel between the first and second terminals of the third controllable switch (Q3).

8. The high-voltage DC shutdown device according to claim 6, characterized in that, The power electronic switch (120) further includes a transient voltage suppressor diode (RV1); the transient voltage suppressor diode (RV1) is connected in parallel between the first terminal and the second terminal of the third controllable switch (Q3).

9. The high-voltage DC shutdown device according to claim 6, characterized in that, It also includes a power module (130), the input terminal of which is connected to the output terminal of the inverter (20), the first output terminal of the power module (130) serves as the second power terminal (V2), and the second output terminal of the power module (130) is connected to the first input terminal of the photovoltaic optocoupler (U1); the power module (130) is used to perform voltage transformation on the voltage provided by the inverter (20) to form the first voltage (V1) and the second voltage provided by the second power terminal (V2).

10. The high-voltage DC shut-off device according to claim 6, characterized in that, It also includes a voltage monitoring module (140) and a control module (150); The input terminal of the voltage monitoring module (140) is connected to the output terminal of the inverter (20), and the output terminal of the voltage monitoring module (140) is connected to the control module (150). The voltage monitoring module (140) is used to monitor the voltage provided by the inverter (20) and form a monitoring voltage (v2). The control module (150) is used to provide the first control signal (ctrl1), the second control signal (ctrl2) and the third control signal (ctrl3) according to the monitoring voltage (v2).

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