Analysis of permanent-magnet machine for sensorless control based on high-frequency signal injection

Abstract

This paper presents the analysis of a surface-mounted permanent-magnet (SMPM) machine for the sensorless control scheme based on the high-frequency fluctuating voltage signal injection method. A simplified high-frequency model of an SMPM machine in the estimated rotor reference frame is developed and a sensorless rotor position and speed estimation algorithm is described. To support this, the high-frequency impedances of an SMPM machine are analyzed by finite-element analysis (FEA) and compared with measurement results using a pulsewidth-modulation (PWM) inverter system under various injection conditions. The results of the FEA and measurements are coincident with each other with some errors due to the nonlinear behavior of the PWM inverter and the SMPM machine. The analysis results give physical insights into selecting the injection conditions for sensorless operation of the SMPM machine even though adjustments considering nonlinear behaviors of PWM inverters are required in the actual operation for the desired performance. The experimental results of speed and position control using a commercial SMPM machine are presented based on the analysis of the SMPM machine for the sensorless control algorithm.Index Terms-High-frequency signal injection, sensorless operation, surface-mounted permanent-magnet (SMPM) machine. NOMENCLATURE SymbolsCoefficient of rotor position information signal (A). Equivalent proportional gain of a bang-bang controller in rotor position estimator. Proportional and integral gains of proportional-integral (PI) controller in rotor position estimator, respectively. Band of bang-bang controller. Resistance ( ).

A Simple Strategy for Sensorless Speed Control for an IPMSM During Startup and Over Wide Speed Range

“…The general HF injection methods use many filters such as a band pass filter (BPF) and low pass filter (LPF) to eliminate the fundamental frequency and extract the HF signal and rotor position [4,[13][14][15]. As the number of filters increases, the time delay also increases, which causes an error in the estimated rotor position.…”

“…1(b), the error of the rotor position component is significantly smaller than that of other components. Therefore, this error can be separated from the HF component by the LPF as shown in (13). Hence, it is possible to reduce the delay time caused by the filter compared to the conventional HF signal injection method that uses both the BPF and LPF.…”

“…Therefore, the high-frequency (HF) signal injection method is introduced. Because the HF signal injection method does not estimate the current and back-EMF, it exhibits great performance at startup and in the low-speed region [12][13][14][15][16]. In contrast to the back-EMF and observer-based methods, the performance becomes worse when the motor operates at a high speed.…”

Improved Transition Method for Sensorless Operation of Interior Permanent Magnet Synchronous Motor Drives

“…따라서 EEMF를 추정함으로써 회전자의 위치각과 속도에 대한 정보를 얻을 수 있다. 하지만 저속과 낮은 토크 영 역에서는 모터의 기전력이 작기 때문에 회전자의 위치각과 속도 를 정확히 추정하기가 어렵다 [12].…”

Design Optimization of Modern Machine-drive Systems for Maximum Fault Tolerant and Optimal Operation

“…These methods can be found in the literature as flux estimation from the voltage model of PMSM [162]; inductance based estimators [163], extended Kalman filters [78], open loop or closed loop state observers [156,157], model reference adaptive schemes [166], artificial intelligence-based estimators [167] and sliding mode observers [75].…”