Magnetic-Characteristic-Free High-Speed Position-Sensorless Control of Switched Reluctance Motor Drives With Quadrature Flux Estimators

Abstract

High-speed position-sensorless control of switched reluctance motor (SRM) drives is often realized by searching <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a priori</i> flux linkage lookup table. However, obtaining the nonlinear flux linkage characteristic requires time-consuming offline measurement and occupies large memory storage. To deal with this problem, this article proposes a new position estimation scheme for SRM drives without using any magnetic characteristics. This feature is achieved by using a quadrature flux estimator (QFE) that can extract the fundamental flux and its quadrature signal from the real-time calculated flux linkage. The flux bias and flux harmonics can also be suppressed by the QFE’s adaptive bandpass capability. Therefore, the proposed method can reduce the nonlinearity in SRM flux linkage and derive simple sine–cos position signals. Afterward, the rotor position and speed can be estimated from the orthogonal flux signals using a three-phase phase-locked loop. To baseline the advantages, comparative experimental validation with the conventional method is conducted on a three-phase 12/8 SRM test bench. The results show that the proposed scheme can achieve the same estimation accuracy as the conventional method even though no magnetic characteristics are used.