Experimental Research On Operating Characteristics Of Permanent Magnetic Actuator Vacuum Circuit Breaker Considering Temperatures

Permanent magnetic actuator vacuum circuit breaker (PMAVCB) has a high mechanical reliability, a simple structure, a long service life and a less dispersion of operating time. It is a "free (less) maintained breaker" that can be ideal applied to various occasion of the grid. But when the ambient temperature changes, the capacitance, the equivalent series resistance (ESR) of capacitor, the coil resistance of the permanent magnetic actuator (PMA), the holding force of the PMA, the jammed extent of mechanical device will change, the circuit breaker operation time will vary with changes in temperature, it is difficult to obtain the trend by theoretical analysis. In some applications that need a high accuracy in action time of the PMA, such as the PMA synchronous closing technology, the appropriate measures should be added to make up the temperature influence.In this paper, a temperature test method was put forward to find the change trend of the PMAVCB operating time as the ambient temperature changed, because the PMAVCB operating time change trend was complex and difficult to analyze based on the theoretical. This paper designed three kinds of test cases to study, how the changes in capacitance parameters effected the VCB closing characteristics, how the changes of the PMA parameters effected the VCB closing characteristics when the temperature changed, how the changes in all PMAVCB parameters effected the VCB closing characteristics. We found that:for the PMAVCB, at a relatively high temperatures, the factors of the capacitor had a limited influence on the closing time of the PMAVCB, but when the temperature was below-20℃, the capacitor ESR increased rapidly, the capacitance decreased rapidly, the capacitor factors would affect the closing time of the PMAVCB significantly. Low-temperature had a significant influence on the mechanical parameters of PMA, it was possible to make the switching action failures occur, it should be given attention. By fitting the experimental data, we obtained the curves of the closing time of the PMAVCB varied with temperatures and verified its reliability. After substituted the test data into the PMA model made by the Ansoft, and completed the simulation, we found that the discharge resistor had a great the impact on the just closing speed of the PMAVCB, the curves of the closing time varied with temperatures that got by simulation was consistent with the curves of the closing time varied with temperatures that got by actual test.In this paper, the trend of the closing time varied with temperatures was obtained, and the empirical formula was fit, it had a high accuracy, which can be used as the closing time temperature feed forward for some time-sensitive applications, liked the permanent magnet synchronous closing action, and analyzed the relationship between each factor and the PMAVCB closing time, we can try to fix coefficient of the fitting formula and make the empirical formula applicable to other permanent magnetic actuator in the later.