In this study, the backstepping control (BSC) design for a high-performance inverter with the functions of stand-alone and grid-connected power supply is developed so that distributed generation units can operate individually or in a micro-grid mode. In the stand-alone power-supply mode, the output ac voltage can supply to ac loads. In the grid-connected powersupply mode, the goal of power management can be achieved by controlling the amplitude and direction of the output current in the inverter. As a result, the proposed high-performance inverter with the BSC scheme has the output voltage with a low total harmonic distortion in the stand-alone power-supply mode and the output current with a high-power factor in the gridconnected power-supply mode to provide an ac output with high-performance power quality. The effectiveness of the proposed high-performance inverter with the BSC is verified by experimental results of a 3 kW prototype, and the merit of the proposed BSC scheme is indicated in comparison with previous proportional-integral control, proportional-resonant control and adaptive total sliding-mode control strategies.

No abstract

Adequate commutation instant setting and tuning in accordance with varied operating conditions are required for achieving good winding current and developed torque responses for a switched-reluctance motor (SRM) drive. This study presents a dynamic commutation shift controller (DCSC) based on DC-link current ripple minimisation for SRM drives. A single-phase bridgeless switch-mode rectifier (SMR) fed SRM drive is established for making the performance evaluation. The robust control schemes of the SMR and SRM drive are properly designed to yield satisfactory dynamic and static operation characteristics. The boosted and well-regulated DC-link voltage is established from the mains to enhance the SRM drive performance under high speeds. In addition, good line drawn power quality with high efficiency is obtained simultaneously by the bridgeless SMR front-end. In the developed DCSC, the observed DC-link ripple current is processed and used to determine the commutation shift angle automatically. Some measured results are provided to demonstrate the performance of the established SMR-fed SRM drive under the commutation using the proposed DCSC.