Fine estimation & self-tuning of both current sensor offset and electrical parameter variation for PM motor

The servo system of PM motor is always required to keep the fine torque response and the fine speed response. The current controller of PM motor should have the fine current response. However, when each current sensor of U phase and V phase has the offset value, the servo system of PM motor has the torque ripple and can not accurately identify the motor parameters such as the motor resistance R_a and the motor inductance L_a. In order to overcome these problems, this paper proposes a new fine estimation & self-tuning of both each current sensor offset and the electrical parameters for PM motor. The proposed method is the real time algorithm using the current simulator, which is the software system of DSP. In this paper, the experimental results confirm that the proposed method well estimates each current sensor offset of U phase and V phase, the motor resistance R_a and the motor inductance L_a individually and accurately, and carries out the fine self-tuning for the current controller of PM motor servo system.