Abstract
The speed sensorless vector control systems have been developed under the sensitiveness of the temperature variations of the secondary resistance. The conventional compensation way is somewhat difficult in the sensorless drive system to calculate the secondary resistance, because of the necessity of the rotor speed.
This paper proposes a secondary resistance calculation method for speed sensorless drive systems, which doesn't need the variable of the rotor speed. The secondary resistance is obtained directly from characteristic equations. It is impossible under the steady state but the equations can be solved under non sinusoidal voltage supplied motor. Therefore, on-line calculation of the secondary resistance is possible in the PWM inverter drive system, and it can apply to the sensorless drive which makes free from the secondary resistance variation.
The effectiveness of the proposed method was verified by some digital simulations and experimental results. By using this method, the compensation for the secondary resistance variations is realized. In this paper, the influence of the variations of the primary resistance, the leakage inductance and the mutual inductance are also investigated.
