In this paper, a predictive phase current control (PCC) scheme based on a local linear phase voltage model for a switched reluctance motor is proposed. The current is controlled by regulating the average voltage through PWM, ensuring a fixed switching frequency. A linear model is proposed to approximate the relationship between the voltage and the current slope in a short period. By using the voltage and current slope information in the previous control cycle, the intercept and slope of the model can be identified online. In the previous control cycle, the phase voltage changes from zero to positive or negative DC-link voltage, and then the identified model is used to predict the average voltage required in the next PWM cycle for the actual current so as to accurately track its reference. The effectiveness of the proposed PCC was verified experimentally. The results demonstrate that the proposed control scheme can significantly reduce the current and torque ripples compared to hysteresis control with the same sampling rate. The proposed PCC is easy to implement, does not need to obtain the motor characteristics in advance and is not sensitive to the changes in characteristic parameters caused by motor aging, etc. It is relatively suitable for applications that need to accurately track the given current curve.

An n/2-sensor-based and an (m + 1)/2-sensor-based phase current detection scheme are proposed for even-numbered switched reluctance motors (EMSRMs) with n phases and odd-numbered switched reluctance motors (OMSRMs) with m phases. For the EMSRMs, the phases are divided into n/2 groups each of which includes two phases furthest from each other, and the lower dc bus is split into n/2 + 1 buses such that the currents through the lower switches of a group flow through a bus whose current is detected by a sensor. For the OMSRMs, the phases are divided into (m + 1)/2 groups and the currents through the lower switches of a group are detected by a multiplexed sensor without converter modification; the phase grouping is generalized as an optimization problem considering the volume and measuring range of the sensors. The schemes can detect the magnetization and freewheeling phase currents under multiphase excitation without pulse injection and voltage penalty. Compared to the existing schemes using cross-winding sensors, the proposed schemes can increase the motor torque by extending the phase conduction region. In addition, the proposed scheme for EMSRMs can combine the low-cost low-side shunt current sensing technique, and the proposed scheme for OMSRMs can increase the current sensing resolution. Simulations are carried out to validate the two proposed schemes. The proposed (m + 1)/2-sensor-based scheme is further verified experimentally.