Single rotor compressor's low frequency control scheme in air conditioner

For practical condition of compressor system, position sensorless scheme must be adopted. Because of low precision of position estimation and the fluctuation of the compressor's load during each mechanical period, the speed ripples and vibration problems are serious in low frequency range by adopting traditional vector control scheme. In this paper, basing on estimation of rotor position, the method of real time load auto estimation is present. Through which torque feed forward compensation can be realized. And then the position sensorless scheme is optimized to attain super low frequency operation. Through the adoption of schemes mentioned above, 1Hz stable operation of compressor is realized. Simulation and experiment results show the effectiveness of the proposed method.