In general, the torque of compressors in the form of fans or pumps has a load proportional to the speed, so more torque control is required as the speed increases. However, since the load torque of the refrigerant compressor is generated in the process of compressing the refrigerant gas, the load torque is generated differently depending on the pressure condition of the system. High torque is required when starting with high differential pressure even at low speed. It has a negative effect on the stability of I-f control and sensorless control. To improve the stability of motor starting, the poles migration of I-f control for the interior permanent magnet synchronous motor (IPMSM) was analyzed using linearization. A damping controller was proposed to improve the starting performance of the motor. The proposed algorithm was demonstrated through experimental results under the initial starting characteristics of the e-Compressor according to the pressure load condition of the refrigerant.
