A Novel Deadbeat Current Control Scheme with an Adaptive Self-Tuning Load Model for a Three-Phase PWM-VSI

In this paper, a novel deadbeat current control scheme with an adaptive self-tuning load model for a three-phase pulse-width-modulated (PWM) voltage source inverter (VSI) is proposed. First, to achieve high bandwidth current control characteristics, an improved deadbeat current controller with delay compensation is adopted. The compensation method forces the delays elements, caused by voltage calculation, PWM, and synchronous frame rotation, to be equivalently placed outside the close loop control system. Hence, their effect on the closed loop stability is eliminated and the current controller can be designed with a higher bandwidth. Second, to relax the parameters sensitivity issue of the deadbeat controller and to realize a control scheme with reduced sensors, a novel adaptive self-tuning load model is emerged in the control structure. The adaptive model is designed with low computational demand to estimate, in the real-time, the load parameters (R, L) and the back EMF voltage simultaneously. A unified solution to the present nonlinear estimation problem is presented by adopting a parallel observers structure. Furthermore, the adaptive model has the necessary phase advance of the estimated quantities; which compensates for the total system´s delay. Comparative evaluation results are presented to demonstrate the validity and effectiveness of the proposed control scheme.