Qiyuan Cheng

The precise control of speed and torque in switched reluctance machines (SRMs) depends largely on high-precision, real-time position information acquired from coaxially mounted mechanical position sensors. However, in the shaft-line-embedded starter/generator (ESG) system, the operating environment temperature exceeds $350~^{\circ }$ C, where mechanical position sensors could not only increase the overall size of the drive system, but also reduce its reliability under high-temperature conditions. To explore the application of SRMs in the integrated starter/generator systems of more-electric aero-engines and remove mechanical position sensor, this article proposes a position sensorless control method based on linear inductance residual calculation combined with delay-compensated second-order generalized integrator frequency-locked loop with soft start-up (DCSOGI-FLL-WSS) to improve the position estimation accuracy at room and high-temperature environments. The performance of position estimation, system efficiency, and torque ripple under rated load, 1.5 times overload, and speed regulation conditions were also compared and analyzed. Experimental results show that the starting process of ESG can be easily achieved by the proposed method under different temperatures conditions. Due to the changes in the parameters of the SRS/G caused by the high-temperature environment, the accuracy of position estimation under the working condition of $350~^{\circ }$ C decreases. However, the proposed method demonstrates advantages in terms of position estimation accuracy, system efficiency, and torque ripple reduction for SRS/G systems.

In this article, a deadbeat predictive control (DPC) method with low measurement effort and the capability to effectively suppress torque ripple is proposed for switched reluctance machine (SRM). First, to enhance prediction model accuracy, a flux-linkage model based on second-order Bézier curves combined with full-position interval interpolation is proposed. This method only requires determining three parameters—aligned-position incremental inductance, unaligned-position incremental inductance, and unaligned-position saturation inductance to accurately describe flux-linkage characteristics. Next, Varignon’s principle is applied to analyze the mechanism by which phase current harmonics influence torque. On this basis, the beetle antennae search algorithm, which enables rapid optimization, is used to optimize the current waveform, resulting in a novel harmonic-optimized current profile. The developed enhanced DPC methodology incorporating pulsewidth modulation demonstrates significant torque ripple reduction under diverse operating conditions, minimal offline measurement requirements, and high estimation accuracy, thus providing an efficient and practical solution for achieving high-performance SRM control in industrial applications.