Design of wireless partial discharge digital calibrator based on LoRa

In order to improve the performance of partial discharge (PD) calibrators, a design of the PD calibrator with wide output charge and high pulse resolution is proposed. The PD calibrator obtains pulse parameters through LoRa, outputs voltages through high-precision DAC, and generates pulses by analog switches. It corrects pulse amplitude by voltage feedback module, and generates 1 pC – 2000pC of charge. The test results show that the pulse amplitude can reach 10V, and the pulse resolution can reach 5kHz. The rising edge time of the pulse voltage is less than 40ns, the amplitude linearity reaches 0.4%, and the charge quantity uncertainty is less than 4%, which in line with the requirements of IEC 60270:2000.