Affiliations: [a] State Key Laboratory of Power Transmission Equipment & System Security and New Technology (Chongqing University), Shapingba District, Chongqing 400044, China | [b] Electric Power Research Institute, Yunnan Electric Power Company, Yunnan 650000, China
Correspondence:
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Corresponding author: Yaqin Tao, State Key Laboratory of Power Transmission Equipment & System Security and New Technology (Chongqing University), Shapingba District, Chongqing 400044, China. Tel./Fax: +86 15213562253; E-mail: [email protected]
Abstract: A double differential D-dot overvoltage sensor is proposed based on the D-dot principle for the purpose of faster and more accurate measurement of overvoltage signals. The proposed sensor is a new D-dot sensor structure consisting of four electrodes. It is applied together with the double differential input structure. This structure allows the sensor to operate in self-integration mode and achieve a wide frequency response characteristic while has a stronger anti-interference capability. The simulation demonstration and parameter design are carried out by using the Ansoft Maxwell. A test platform is constructed and used in the steady-state performance and lightning impulse transient-state test of the sensor. Test results demonstrate that the double differential D-dot sensor has satisfying steady-state performances, manifested by small measurement phase and amplitude errors. It can be applied to internal overvoltage measurement of power system. Moreover, the double differential D-dot sensor is equipped with good transient characteristics. The relative error of the lightning wave rise time which is measured by the double differential D-dot sensor is controlled in the range of ±1.7% and the relative measurement error of lightning wave peak is smaller than ±2.0%. It can measure external overvoltages effectively.
