Permanent magnet synchronous motors (PMSM) are widely used in industrial manufacturing, transportation and household appliances because of their high power density and excellent performance. In consideration of reducing the size of the control device, cost reduction and system operational reliability, it is necessary to abandon the position sensor and realize the sensorless control of permanent magnet synchronous motor. At present, the magnetic chain observer method is one of the most commonly used and easy to implement algorithms for sensorless control of permanent magnet synchronous motors....