Development of 300-kV Air-Insulation Standard Impulse Measurement System

This paper describes the development of a 300-kV standard full lightening impulse measurement system. The high-voltage (HV) arm of the impulse resistive divider was constructed with an air-insulation frame wound with nichrome alloy resistance wire using the Ayrton-Perry winding method. The winding inductances of different frame cross-sectional shapes were studied. The result showed that the rectangular shape gives the least winding inductance compared with the circular and square cross sections under the condition of the same circumference. The HV arm was divided into 10 sections, and the stray parameters were subtracted with Finite Element Method; the step response of the system is simulated with Simulink of MATLAB to optimize shield ring design. The low-voltage arm is composed of 24 low-inductance metal film resistors, which is similar in design to that developed by a Russian national metrology institute. The step response measurement result showed that the partial response time was less than 5 ns. The convolution method is used to evaluate uncertainty due to different waveform shapes based on the normalized step response. The expanded uncertainty evaluation of peak value gives 0.5% (k = 2), and the time parameter T₁ is 2.6% (k = 2) and T₂ is 1.3% (k = 2).