Transformer protection method and protection device with exciting inrush current restrain and switch parameter detection

Abstract

The invention provides a transformer protection method and a protection device with exciting inrush current restrain and switch parameter detection and relates to the technical field of transformer protection in the power transformation and distribution process. The protection method comprises the following steps of: firstly, detecting the state change of a circuit breaker on a real-time basis; secondly, dynamically evaluating the state of the circuit breaker; thirdly, collecting the position of an auxiliary contact of the circuit breaker and the voltage of a power grid and calculating the change on the voltage phase position of the power grid in real time; fourthly, obtaining a method for restraining the exciting inrush current and obtaining an expected closing phase position; fifthly, calculating the effect of the closing delay time to obtain a phase position Qon_c and sending out a closing command after the expected closing phase position is obtained; and sixthly, enabling a master control system to send out a closing command after a voltage phase position of a power supply reaches the Qon_c. The device comprises a CPU (Central Processing Unit) main board, a sampling board, a power supply, a switch input board, a logical board, a display board and the like, wherein the CPU, the sampling board and the power supply are inserted on a backboard. Through the transformer protection method and the protection device, the no-load closing exciting inrush current of the transformer can be reduced to below 30 percent of rated current, so that the bad effect of the exciting inrush current on the power grid and the transform is completely eliminated.

Description

technical field [0001] The invention relates to the technical field of transformer protection in the power transformation and distribution process, in particular to a transformer protection method and device with excitation inrush current and switch parameter detection. Background technique [0002] Power transformers and high-voltage circuit breakers are important power equipment and are widely used in power grids. Considering the safety and stability of the power grid and effective protection equipment, the transformer is generally connected to the high-voltage power grid through a high-voltage circuit breaker and equipped with a special transformer protection device to realize selective automatic tripping when the transformer itself fails or a fault occurs within the scope of power supplied by the transformer. Open the circuit breaker and isolate the fault. The excitation current of the transformer in normal operation is very small, but due to the structural principle of...

AI Technical Summary

Problems solved by technology

The performance degradation of the high-voltage circuit breaker after long-term use is a great hidden danger to the safety of the power grid. The operating parameters of the high-voltage circuit breaker can comprehensively reflect the overall performance of the high-voltage circuit breaker body and the operating mechanism to a certain extent. The traditional method is only before the initial investment. Or the relevant parameters of the high-voltage switch can be detected with the help of special test equipment during power failure maintenance, and real-time, online detection and dynamic diagnosis cannot be achieved

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