Closed Loop Control of Renewable Source Fed Asymmetrical PWM Full Bridge Converter

Abstract

This paper presented a closed loop control of asymmetrical PWM full bridge converter; Renewable energy and distributed generation are getting more and more popular, wind turbines, and fuel cells. The renewable energy sources need the power electronics interface to the utility grid because of different characteristics between the sources and the grid. No matter what renewable energy source is utilized, extended voltage and power output, less maintenance and higher fault tolerance, the asymmetrical PWM full bridge converter  are good, for utility interface of various renewable energy sources. This dissertation proposes a new PWM converter topology and control scheme. Compared to traditional converter, they have enhanced system reliability to no shoot-through problems and lower switching loss with the help of using power closed loop control. The closed loop control, it theoretically eliminates the inherent current zero-crossing distortion of the single-unit asymmetrical type PWM full bridge converter. In addition, the closed loop control can greatly reduce the ripple current or cut down the size of passive components by increasing the equivalent switching frequency. An asymmetrical full bridge PWM technique is proposed for closed loop control of renewable energy sources.  The proposed approach is to cut down the switching loss of power control.  At the same time, this PWM full bridge leads to current ripple reduction, and thus reducing ripple-related loss in filter components. PWM with feedback controlling is employed for the voltage control of the system. A power management system is designed for the proposed system to manage power flow among different sources.