UHVAC GIS on Site Power-Frequency Voltage Tests and Restricted-frequency Principle of Frequency-regulating Resonance Devices

Zhang Wenliang, Zhang Guobing
HIMALAYAL - SHANGHAI - CHINA

Abstract: Aiming at UHVAC GIS on site power-frequency voltage tests, two problems including the site-adaptability of power-frequency resonance devices and the power-frequency strict compliancy of frequency-regulating resonance devices become more remarkable. Through discussing the classification of testing frequency bound, it is indicated that the high voltage tests in the testing power frequency bound (45-65Hz) satisfy the requirement of power-frequency strict compliancy. So a restricted-frequency scheme principle of frequency-regulating resonance devices is put forward, i.e. The testing-circuit resonance is obtained by means of regulating frequency in the testing power-frequency bound, and the tuning range of the testing capacitors is magnified with deploying parallel-capacitors. Finally, in order to simplify the testing circuit,a basic regulation of the scheme of UHVAC GIS on site power-frequency voltage tests is proposed, i.e. The testing frequency is restricted in the testing power-frequency bound or within some extend to the best of its abilities by means of selecting suitable testing devices and their parameters. 

Key words: UHVAC GIS, on site power frequency voltage test, series resonance device, testing frequency

I. Introduction
According to GIS current standards, there are two different test proposals for GIS on site power frequency voltage test: one is to adopt power-frequency resonance device while the other is to utilize frequency-regulating resonance device. The principle of selecting test proposal is as follows: power-frequency resonance device should be given priority over the other. But the frequency-regulating resonance device can also be selected if the condition does not allow. GIS current standards are mainly applied for 550kV and less than 550 voltage grade. As for the UHV, two problems become more remarkable,  including the site-adaptability of power frequency resonance device and the power-frequency strict compliancy of frequency-regulating resonance device .