Control system for low-speed running of permanent magnet motor

The invention discloses a control system for low-speed running of a permanent magnet motor, which consists of a speed controller, a current loop, an angle sensor, a disturbing estimator, a tooth socket torque estimator and a tooth socket torque calculator. The sizes of the tooth socket torque and the rest resisting moments are quickly calculated by the disturbing estimator and the tooth socket torque estimator; the influence of the tooth socket torque on the speed is further accurately calculated through the tooth socket torque calculator so as to make compensation; the stability of the control system is increased by controlling integral coefficients of the speed controller in real time, and equivalently, output current is changed through changing the integral coefficients to compensate for aperiodic resisting moments at the same time; and the response speed of the control system is increased by carrying out the advanced compensation of the delay of the controller so that the disturbance is quicker to attenuate. The control system has higher correctness and stability, and is particularly suitable for realizing the low-speed control of the permanent magnet motor under the condition of the larger change range of the resisting moments.