塑壳断路器可靠性试验电源的光纤校准技术研究OACSTPCD

In consideration of the characteristic properties of the reliability test current for the molded case circuit breakers(MCCB)including high value,short time and AC/DC hybrid and the high requirements of field conditions to the reference high current sensors,a field calibration method of reliability test power supply for the MCCB based on the fiber-optic current sensing technology is proposed.The dynamic model of the sensor is established according to the closed-loop signal-detecting principle of the fiber-optic current sensor.The step response and frequency response characteristics of the system are analyzed.The simulation results show that by adjusting the forward gain and sliding filter order of the system,the rise time of the sensor is better than 9.09 μs,and the-3 dB bandwidth can reach 39.91 kHz,and prove the tracking response capability of the sensor to the reliability test current of the MCCB.The fiber-optic current sensor is calibrated based on the equal ampere-turn method.The uncertainty of the calibration result is evaluated,and the results show that within the range of 2.5 kA to 60 kA,the measurement accuracy of the sensor's DC and power frequency currents is better than 0.2％.The field test of the reliability test current of the MCCB is performed.The mentioned research provides a technical route for the field calibration of the reliability test power supply of the molded case circuit breaker.