Secondary neutral point multipoint grounding monitoring deivce of voltage transformer of transformer substation

Abstract

A secondary neutral point multipoint grounding monitoring deivce of a voltage transformer of a transformer substation comprises a one-point grounding loop connected with a secondary neutral point of the voltage transformer, wherein a single-turn through current sensor is connected onto the one-point grounding loop. The secondary neutral point multipoint grounding monitoring deivce is characterized in that an analog / digital (A / D) data conversion module is connected onto a current sensing coil; the output end of the A / D data conversion module is connected into a micro-programmed control unit (MCU) microprocessor; and an alarming circuit, an internal memory, a communication module, a power supply processing module, a liquid crystal display (LCD) module, a key operation module and a time clock signal control module are connected onto the MCU microprocessor. Compared with the prior art, the secondary neutral point multipoint grounding monitoring deivce can store current values, give alarms and transmit the current values to a remote monitoring platform when the current values surpass the preset value by monitoring and judging secondary neutral current. In addition, compared with the traditional monitoring method, unattended operation is achieved, and a large amount of time and labor force wasted in the existing monitoring process is saved.

Description

technical field [0001] The invention relates to a secondary neutral point multi-point grounding monitoring device for a voltage transformer of a substation, and belongs to the technical field of electric power system relay protection. Background technique [0002] In this case, a 500kV substation is taken as an example. When the secondary neutral point (N600) of the voltage transformer of the 500kV substation is grounded at multiple points, a line short-circuit fault occurs, and the fault current flows in the ground network to form a voltage, which is superimposed into two The sub-neutral point will cause the phase voltage sensed by the relay protection device to be distorted, causing the relay protection device to refuse to operate or malfunction, resulting in a power grid accident. The invention patent with application number 201120254560.1 is a simple secondary neutral point multi-point grounding monitoring device. It is constructed as figure 1 As shown, including the p...

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