Self-starting characteristic simulation of the U-core motor

Self-starting capability is one of the key issues in motor design. In order to clarify this problem, this paper conducts a simulation analysis of the self-starting capability of U-shaped core motor. First of all, the cogging torque was simulated with different sizes of asymmetrical air gaps, and the initial position of the rotor was determined by using the point of zero torque. Secondly, under zero excitation, transient simulation method was adopted to make the rotor reach the equilibrium position by the cogging torque alone. These two methods are mutually verified to prepare for the next self-starting simulation. Then, under the transient simulation, the excitation is applied, and the air gap and rotor inertia are changed respectively to study their influence on the self-starting ability of the motor. The simulation results show that the asymmetrical air gap design provides the possibility of self-starting of the motor, but the self-starting ability of the motor and the asymmetrical structure and inertia are non-uniform. For a specific motor, only the air gap and inertia match each other to ensure a good self-starting capability of the motor, the matching of motor parameters is the key.