Grid-Voltage-Sensorless Control of Integrated On-Board Charging System Based on Switched Reluctance Motors

Recently, a compatible integrated on-board charging (IOBC) solution for electric vehicles (EVs) based on switched reluctance motors (SRMs) has been reported, which can achieve three different charging modes by reusing the windings of the SRM and certain parts of its asymmetric half-bridge (AHB) drive converter. However, in this solution, grid voltage sensors are required for the single-phase and three-phase AC charging modes, which is undesired for the cost and reliability considerations. In this paper, a grid-voltage-sensorless control method is proposed for both the single-phase and three-phase charging modes, thereby further enhancing the low-cost advantage of the IOBC solution for SRM. The core idea of this paper is to estimate the grid voltage phase angle from the input current, thus achieving single-phase interleaved one-cycle control (OCC) and three-phase AHB PWM control without any grid voltage sensors, which are both obtained by properly reconstructing the SRM drive circuit. The feasibility and effectiveness of the proposed control strategy is validated through experiments on a three-phase 12/8 SRM platform. Experimental results shows that the proposed method works well under dynamic conditions or non-ideal grid voltage conditions, for instance, sudden phase change, sudden frequency change, grid voltage distortion or asymmetrical amplitude, etc.