Enhanced Model Predictive Wattful and Wattless Control of Multi-Phase Grid-Interactive Inverter with Duty Cycle Optimization

The control of model-based predictive complex power control (MBPCPC) has been adopted in contemporary times to regulate the injection of both wattful power and wattless power in grid-interactive systems to lower total harmonic distortion. However, the MBPCPC designs are unable to live up to their expectations due to the use of singular rectangular voltage during one control interval. This paper presents an enhanced MBPCPC for a multi-phase inverter grid connected with smoother (LCL). The improved design uses an optimal duty cycle and it is based on model predictive as well as complex power control (CPC). Wattless and wattful power are controlled individually in the MBPCPC control by using a proper discrete time prediction model and minimization of the cost function for optimal operation of the switches in the inverter. This is achieved with the inception of an optimal duty cycle in the MBPCPC by employing a zero and non-zero rectangular voltage in one control interval. The achieved effects from simulations confirm the efficiency of the enhanced MBPCPC during various tests vis-a-vis the conventional strategy. The proposed design produces good steady-state and dynamic performance with better dynamic response and lower total THD.