Design of real time system to measure the voltage signal in high voltage power supply

Abstract

The output voltage signals should be measured in real-time, and it is sent to a control system for feedback control and protection in the high-voltage power supply with high-voltage, strong magnetic field, or strong power condition. In order to obtain a stable output voltage and a rapid response of the protection in the high-voltage power supply system, the measurement of the voltage signal needs to meet three requirements: response in real-time, accurate, and high isolation. Using the voltage-to-frequency (V/F) converter AD650 to transmit the analog signals as frequency form through the digital optical fiber is the best mode to measuring the signals with high precision, real-time, long-distance, and high isolation. The composition and principle of the real-time voltage measuring device are described in this paper. The design of the hardware and the parameters are analyzed and discussed in detail. The experimental results show that the circuit structure based on the AD650 chip is simple. The optical fiber transmission can achieve high isolation and high accuracy (better than 0.1%). The low response time (under 30us) can meet the requirements of the real-time voltage signal measurement system. The signal will not be affected by the high electromagnetic field in the transmission process. The measurement system has been applied in the high voltage power supply with excellent linearity and high isolation.