Review of Precise Position Estimation Method of PMSM with Low-Resolution Position Sensor

Servo motor has been widely used in household appliances, new energy utilization and equipment manufacture. To obtain high precise rotor position information, the rotary transformers or photoelectric encoders are often adopted, but their prices are relatively high in general thus may add the system design cost. The sensorless technology can barely meet the application standards of industry utilization and household appliances. However, the low-resolution position sensor technology can guarantee the motor operation performance, which will effectively reduce the system cost and enhance the system reliability. In this paper, the application method and operation principle of switching hall position sensor are introduced, the coming source and correction method of the original hall positional information error are summarized. The rotor position/speed estimation strategies, such as interpolation method, synchronous frame filter method and observer method, are discussed in detail. The analysis and comparison of principles, advantages, disadvantages, application scopes and application conditions of different estimation methods were conducted from the aspects of the enhancement of motor system performance under low speed with low resolution position sensor. Lastly, existing research achievements and issues to be solved are summarized. © 2017, The editorial office of Transaction of China Electrotechnical Society. All right reserved.