1105 / 2019-05-20 20:42:53

Research on the Characteristics of UHV GIS Disconnector Operation Electromagnetic Compatibility of Relay

ultra-high voltage；GIS；transient enclosure voltage；disconnector；grounding lead；enclosure transient circuit of GIS；Electromagnetic Compatibility; Microcomputer-Based Relay; EMC

The ultra-high voltage system has the properties of high voltage grade, huge transmission capacity and rather sever electromagnetic transient problems. In order to investigate the transient characteristics of enclosure voltage when disconnector operating in ultra high voltage GIS,the calculation theory of transient over-voltage outer the GIS under ultra-high voltage was clarified based on a 1100kV GIS in China. The transient enclosure voltages on each point of GIS were calculated using multi-condutor model, the spectrums of which were realized,too. In addition, the factors effected on TEV, which were disconnector operation types, operation phase, grounding types and so on, were analyzed. The values of VFTO on each key equipment were calculated on the condition of considering enclosure transient circuit of GIS. The transient characteristics of TEV and the general laws of factors affecting the TEV obtained by calculation and analysis.The anti-interference measures from the aspects of the shield, the earth and the filter are proposed. The anti-interference approached of the design of the microcomputer-based protective relay’s hardware is given.
In this paper,the problem of the external transient over voltage based on 1100kV GIS substation was studied, and the conclusions are as follows.
(1)TEV was changed by different operations of the switch. Maximum value appeared in the operation phase of the pipe shell on the incoming or the leading-out of the pipe. The maximum can reach to around 50kV, and it contains a variety of frequency components, the frequency distribution is around 1.5MHz.
(2)At the leading-out segment of the GIS, the amplitude of the TEV also has the nature of symmetry due to the decoration of the symmetry. When A,B and C phase was arranged by horizontal layout, the TEV produced by the operation of B phase is higher than that of A phase. The aim is to suppress electromagnetic interference,
(3)Increasing the number of ground wire and the multipoint earthing at the same point can reduce the peak value of TEV. When the earthing line more than 2 roots, the dropping effect is not obvious.
By analyzing TEV characteristic, the suppression measure of using the electromagnetic compatibility of the grounding, shielding and filtering electronic equipment and system was proposed. Only the correct use of these technologies can restrain the interference to achieve the ideal effect.