Ground screen shunting vector test system and method with GPS synchronization

Abstract

The invention provides a ground screen shunting vector test system and method with GPS synchronization. The test system comprises a host unit and a shunting vector test unit; the host unit comprises a first CPU, a first GPS module, a first wireless data transmission module, a first A / D conversion module and a first current sensor, wherein the first GPS module, the first wireless data transmission module and the first A / D conversion module are connected with the first CPU, and the first current sensor is connected with the first A / D conversion module; and the shunting vector test unit comprises a second CPU, a second GPS module, a second wireless data transmission module, a second A / D conversion module and a second current sensor, wherein the second GPS module, the second wireless data transmission module and the second A / D conversion module are connected with the second CPU, and the second current sensor is connected with the second A / D conversion module. According to the method, the ground screen shunting vector of a metal frame of a transformer station of a metal oversheath of a cable can be tested, and thus, the ground screen characteristic parameters, including the grounding impedance, the step voltage, the contact voltage and the potential distribution, measured in the present standard method can be corrected.

Description

technical field [0001] The invention relates to the technical field of testing the influence of the metal frame of the large-scale ground network of a substation and the grounding of the metal outer sheath of the cable on the ground network parameter test shunt, in particular to a ground network shunt vector test system and a test method using GPS synchronization. Background technique [0002] The shunt coefficient of the ground grid refers to the ratio of the fault current flowing through the substation ground grid to the total fault current at the short-circuit point. It is an important parameter that must be considered when designing the substation ground resistance and calculating the ground potential rise, step voltage and contact voltage. In order to reduce the shunt coefficient of the ground network, the overhead transmission lines connected to the substation should be erected with lightning protection lines with good conductivity and be reliably connected to the groun...

AI Technical Summary

Problems solved by technology

[0003] The large-scale substation (converter station) grounding network of the UHV AC and DC transmission system has a large coverage area and complex structure. In order to meet the requirements of reliable operation of the power grid, it is necessary to minimize the ground fault current of the ground network and increase the size of the overhead transmission lightning protection line. And the shunt capacity of the metal outer sheath of the cable, the circulation of the large-scale structure is more complicated, the electromagnetic environment is more harsh, and it is more difficult to accurately measure the shunt coefficient of the ground network

Moreover, it is difficult to untie all the shunt paths to eliminate its influence when measuring the characteristic parameters of the grounding grid according to the method specified in the standard, so that the measured grounding impedance, step voltage, contact voltage and potential distribution are smaller than the actual values, resulting in major system errors and affecting Reliable operation of the power grid

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