Control circuit and control method for power switching device

Abstract

The invention discloses a control circuit and a control method for a power switching device. The circuit comprises a wind power storage standby power supply system, wherein the wind power storage standby power supply system comprises a power conversion system PCS, and a first output end of a switching power supply PW1 is connected with a first input end of an energy storage capacitor C1; a first output end of the energy storage capacitor C1 is connected with a relay KM1; two ends of the energy storage capacitor C1 are connected in parallel with a power-on delay relay KA1; a second output end of the switching power supply PW1 is connected with an input end of a power-on delay relay contact KA1-1; an output end of a power-on delay relay contact KA1-1 is connected with the first input end of the K, and a second output end of the power conversion system PCS is connected with a second input end of an energy storage system control switching relay K; an output end of the energy storage system control switching relay K is connected with the relay KM1; a first output end of the PCS is connected with a load; and the two ends of the energy storage system control switching relay K are connected with a KM1 self-locking switch KM1-1 in parallel. According to the control circuit and the control method, reliable operation of a wind power energy storage power supply switching device is ensured with low cost and the simple circuit.

Description

technical field [0001] The invention relates to the technical field of power switching, in particular to a control circuit and a control method for a power switching device. Background technique [0002] In order to ensure the normal operation of the yaw system during a typhoon and improve the disaster resistance of the wind farm, the wind farm needs to add an energy storage system to provide backup power for the yaw system of the unit. The wind power energy storage backup power system needs to have the function of on-grid and off-grid switching. It needs to be able to close the switch when the power comes from the grid without any auxiliary power supply. The wind power storage backup power system diagram is as follows figure 1 shown. [0003] In the utility model patent application document with the application number CN201120401943.7, a power switching circuit for an AC drive is proposed, including a main circuit, the main circuit includes a rectifier circuit, a filter c...

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Problems solved by technology

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art, and provide a control circuit and control method for a power switching device, which is used to solve the problem that the wind power energy storage power switching device in the prior art has no mature solution in the market at present. The start-up impulse current of the coil is large, and the current is small when it is maintained. It requires a lot of power to drive with a traditional switching power supply, and it does not meet the technical problems of providing energy for the coil during low-voltage ride-through of the power grid.

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