Disconnection protection method for comparing line voltage vector differences on two sides of line with spare power automatic switching

Abstract

The invention discloses a disconnection protection method for comparing line voltage vector differences on two sides of a line with spare power automatic switching. According to the method, the faultcharacteristics of PT secondary voltages of transformer substation buses at a power supply end and a load end during single-phase disconnection of the line are fully utilized, the voltage vector differences of the buses at the two ends of the line are compared, the power supply side circuit breaker or the load side circuit breaker of the single-phase disconnection jumper line of the line is identified, and the method is simple and easy to implement. Voltage information on two sides of the line is transmitted through a line optical fiber channel, the line voltage amplitude differences on two sides of the line are compared to identify line breakage, the power supply side circuit breaker and the load side circuit breaker of a jump line, the relay protection scheme that the transformer losingthe power supply is recovered to the standby power supply for power supply by the spare power automatic switching action of the load-end transformer substation, the starting and tripping of the incoming circuit breaker and the closing of the standby power supply circuit breaker can effectively prevent the influence of the open-phase power supply of the transformer on the power grid and the load power supply, and the disconnection protection method is beneficial to the safe and stable operation of the power grid.

Description

technical field [0001] The invention relates to a disconnection protection method for comparing the line voltage vector difference on both sides of the line and cooperating with automatic switching, and belongs to the technical field of protection and control of electric power transmission and distribution networks. Background technique [0002] At present, there are 3~66kV (including 3, 6, 10, 20, 35, and 66kV) line disconnections in various power grids. The disconnection causes the transformer powered by the line to run without phase, making the three-phase voltage of the transformer asymmetrical, and supplying power to the load. If there is an impact, it may damage the electrical equipment, such as causing damage to the motor due to lack of phase operation. In the prior art, there is no relay protection device and method specifically for disconnection of 3-66kV lines. The present invention will propose a way to transmit the voltage information on both sides of the line t...

AI Technical Summary

Problems solved by technology

[0002] At present, there are 3~66kV (including 3, 6, 10, 20, 35, and 66kV) line disconnections in various power grids. The disconnection causes the transformer powered by the line to run without phase, which makes the three-phase voltage of the transformer asymmetrical and supplies power to the load. If there is an impact, it may damage electrical equipment, such as causing damage to the motor due to lack of phase operation, etc.

In the prior art, there is no relay protection device and method specifically for 3-66kV line disconnection

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