Verification Method for Peak Voltage of Impulse Voltage Calibrator based on Diode Bias Compensation
Zhaozhi Long, Wenting Li, Jiawei Fan, Kangmin Hu, Yinglong Diao, Shaobo Liu · 2024
The impulse voltage calibrator is the key piece of equipment for the traceability of impulse voltage measuring systems or digitizers. The uncertainty in the peak voltage and time parameters of the self-built impulse voltage calibrator are evaluated from the standard uncertainties in the components of the impulse forming network and charging voltage. The influence of the stray parameters of the pulse network on the uncertainty in the peak voltage is related to the evaluation method. In addition, the peak voltage of the calibrator varies with the connected load, and the stray capacitance of the load is difficult to accurately evaluate. This paper describes the feasibility and traceability of a peak voltage verification method for a self-built standard calibrator. Based on the unidirectional conduction characteristics of the diode, the peak value of the impulse voltage waveform is equivalent to the sum of the DC voltage, weak pulse voltage and instantaneous forward voltage drop of the diode. The circuit simulation method is used to determine the parameters of the verification circuit and the selection of diodes. An uncertainty evaluation method for the verification method is proposed. Compared with the GUM method, the method proposed in this paper has a smaller measurement uncertainty for higher voltages.