Experimental Research on Speed Control of Vacuum Breaker

For phase-controlled vacuum breakers, the acting time of the actuator should be precise. The variation of capacitor voltage, capacitance, and environmental temperature impact the dispersion of closing time seriously. A new technology has been put forward in this paper. It is the speed control of the vacuum breaker. This technology can be used for phase-controlled operation of vacuum breakers. By using this technology, the deviation of displacement can be corrected in real time. So the permanent-magnetic actuator (PMA) can move along with the given displacement curve. Also, the closing time is stable when the external factors, such as capacitor voltage, capacitance, and environment temperature change. The closed-loop system has been established in this paper. The proportion-differentiation (PD) algorithm and fuzzy algorithm are used in the system. The PD algorithm adjusts the coil current to ensure that different actuators have the same excitation time. And the fuzzy algorithm is used to adjust actuator displacement. With the use of the algorithm, the closing time of the breaker is stable, and mechanical properties are optimal. Based on the aforementioned theory, many experiments have been performed when external factors change, such as environment temperature, capacitance, and so on. The results prove that the displacement deviation can be corrected using this method and the closing time can be stabilized within ±0.5 ms. Therefore, not only can the accuracy of phase-controlled operation can be ensured, but the lifespan of the circuit breaker can also be prolonged.