Detection system for capacitive bushing provided with measurement terminal and end-screen ground terminal

Abstract

The invention discloses a detection system for a capacitive bushing provided with a voltage measurement terminal and an end-screen ground terminal. The detection system comprises a bushing, an alarm module and a circuit breaker. The system further comprises a voltage detection circuit and a current detection circuit, wherein the voltage detection circuit and the current detection circuit are used for detecting the change of the electric field and the change of the current inside the bushing. The voltage detection circuit and the current detection circuit are connected in series and then are connected between the voltage measurement terminal of the bushing and a grounding point. Voltage and current measurement signals are sent to a monitoring and protection processing module to be processed. The output end of the monitoring and protection processing module is connected with the alarm module and the circuit breaker. The monitoring and protection processing module judges whether the bushing breaks down or not according to the detected change value of the voltage and the detected change value of the current. Based on the system, the state of the bushing can be monitored, so that the bushing can be reliably protected.

Description

technical field [0001] The invention relates to the technical field of electric power transmission and transformation, in particular to a detection system for a capacitive bushing with a measuring terminal and an end-screen grounding terminal. Background technique [0002] Transformers are core equipment widely used in power system substations. The internal winding of the transformer can only be connected to other high-voltage equipment through high-voltage bushings, and the electrical connection between indoor high-voltage equipment and outdoor high-voltage equipment must pass through wall bushings. For the structure of the high voltage bushing, please refer to figure 1 , The bushing 1 includes a high-voltage and high-current conductive rod 2, a porcelain bottle 3, a capacitor layer 4 between the conductive rod 2 and the porcelain bottle 3, an end screen 5 of the capacitor layer and a ground terminal 6 of the end screen. The capacitive layer 4 is made of aluminum foil and...

AI Technical Summary

Problems solved by technology

[0005] However, such a detection circuit structure has its defects, mainly in the current transformer for measuring the current of the last screen and the external capacitor C for measuring the voltage. 1 It must be connected in series between the grounding terminal of the end screen and the grounding point. During operation, the end screen may be open due to vibration and other reasons, which will bring risks to the bushing

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