Transformer substation secondary grounding monitoring device and method

Abstract

The invention relates to a transformer substation secondary grounding monitoring device and method. The device comprises a direct current resistance test module, a control module, a conversion moduleand an alarm display module; the conversion module, the direct current resistance test module, the control module and the alarm display module are sequentially connected with one another; the alarm display module has four alarm modes; the conversion module comprises resistance detection wires with different numbers; and the resistance detection wires are connected to a zero line of a current transformer or a voltage transformer, so that the transformer substation secondary grounding monitoring device can monitor grounding loop resistance values of which the number is equal to that of the resistance detection wires at the same time. According to the device and method of the invention, automatic real-time monitoring of the secondary grounding condition of a transformer substation is realized, fault problems under different mode alarms are provided for workers, and the workers can be facilitated to quickly solve the faults and perform operation and maintenance of the transformer substation.

Description

technical field [0001] The invention belongs to the field of relay protection, in particular to a substation secondary ground monitoring device and method. Background technique [0002] The grounding of the secondary system of the substation is mainly used to protect personal safety and shield interference signals. If there are problems such as virtual connection or multi-point grounding in the secondary grounding, it may cause inaccurate sampling values ​​of voltage and current loops and cause protection failure. Incorrect action, a 500kV substation once occurred due to the grounding of two points in the current loop. When the fault current passes through the grounding grid or is in a strong magnetic field, a small potential difference will appear between the two grounding points on the grounding grid. After the normal sampling is superimposed on the interference current, the Malfunction of protection. The 220kV transmission system in a certain area is equipped with high-f...

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Problems solved by technology

If the secondary ground is falsely connected, it may also cause overvoltage, which may cause damage to equipment and personnel.

At present, the secondary equipment of the substation does not have an automatic monitoring method for the grounding of the secondary system. It can only rely on the inspection of the secondary wiring process during the acceptance process. Current method, signal injection method, unbalanced load current method, phase comparison method, etc., the manual operation process is relatively complicated, the degree of automation is low, and problems cannot be found in time

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