Design of permanent magnet motor actuator used in 550 kV gas-insulated switchgear disconnector

To improve the operating characteristics of disconnector, a limited rotating angle permanent magnet motor actuator is presented in this article. The mathematical relationship between the moving contact stroke and rotation angle of motor is obtained by analyzing the dynamical coordination characteristics of motor actuator used in 550 kV gas-insulated switchgear disconnector. The electromagnetic field equation of motor, motive equation of rotor, and circuit equation of winding are solved simultaneously for acquiring dynamical characteristics of motor. The electromagnetic-mechanical coupled calculating model of motor is established by finite element method, and magnetic saturation of stator tooth is calculated and analyzed. According to the operating principle of motor, the double-closed control system which collects the motor speed and contact stroke signal during the operation of disconnector is developed. The experimental results show that the opening and closing speeds of disconnector are 1.1 and 1.2 m/s, respectively, which meet design requirements. The speed-regulating operation of disconnector is also carried out so that the switching speed of disconnector can adjust by motor actuator and control system.