In sensorless control method of interior permanent magnet synchronous motor(IPMSM)

the high-frequency square wave injection methods have fewer filtering links

therefore

presenting better dynamic performance of position observation loop. However

due to non-ideal factors such as inverter nonlinearity and current measurement error

numerous harmonic components appear in the observed rotor position

thus

the accuracy of observed rotor position is limited. The second-order generalized integrator has been widely used in grid-connected inverter control system on account of its good harmonic suppression ability

nevertheless

its dynamic response ability is weak when the frequency of input signal changes rapidly. In order to take into account both the dynamic performance and steady-state accuracy of IPMSM sensorless control system

a compound rotor position observation method was proposed. In terms of the large estimation error caused by non-ideal factors in the conventional current demodulation process

the low frequency and high frequency harmonic components were uniformly suppressed by a second-order generalized integrator. The dynamic performance of the compound rotor position observation method was guaranteed by designing the switching criterion between the conventional current demodulation method and the current demodulation method based on the second-order generalized integrator

also

the adverse effects caused by the weak dynamic response ability of the second-order generalized integrator are avoided. Experiments based on platform with an 18 kW permanent magnet synchronous motor verify effectiveness of the proposed method.