Implementation of Closed-Loop Control of NSC-Drive with Reactive Power Compensation

Abstract

This paper presents a closed-loop control scheme of the AC–DC–AC nine switch converter (NSC) with induction motor operated under dynamic loading conditions. In industries, induction motors are widely used which are operated at lagging power factor and different loading conditions. The electrical distribution company demands high power factor operation, and it gives benefits to the consumer on operating a system closer to unity. The scope of this paper is to control active and reactive power flow between NSC-drive and utility within NSC converter operating constraints. The control scheme is developed such that the active power required for the induction motor is directly transferred from the utility without affecting DC-link voltage. Also, the NSC with induction motor is used to operate at unity power factor and even at leading power factor. On operating NSC at desired leading power factor, the required reactive power at the point of common coupling can be compensated. The proposed control algorithm is implemented in MATLAB software as well as in the hardware. The 5 KVA prototype of NSC is developed in the laboratory. Software and hardware results confirmed the practicability of the proposed control technique.