A Study of Temperature Effects on the Action Dispersion of Monostable Permanent Magnet Mechanisms

During the phase-selective tripping process of vacuum circuit breakers, temperature changes can cause an increase in the dispersion of the permanent magnet mechanism’s action. This paper investigates the magnitude of the action dispersion of the vacuum circuit breaker closing process when the control circuit of the monostable permanent magnet mechanism and the body of the mechanism are subjected to parameter changes caused by temperature effects. According to D’Alembert’s equation of motion, voltage balance law, Maxwell’s law and thermal balance equation, the calculation model of action time under the influence of temperature is established. Through the finite element calculation software, the control circuit and the permanent magnet are analyzed from the two aspects of the influence of temperature change, and it is concluded that the low temperature has a greater influence on the control circuit, and the high temperature has a greater influence on the permanent magnet. Finally, the whole machine is analyzed by the influence of temperature change, and it is concluded that when it is affected by temperature, the action time dispersion of monostable permanent magnet mechanism, which provides a basis for the vacuum circuit breaker with monostable permanent magnet mechanism to compensate for the control time of selective phase breaking and closing.