An Overview Towards the Design and Control of Standalone and Grid Connected Hybrid Energy Systems and its Performance Assessment

Hybrid renewable generators are attractive solutions to achieve sustainable and clean electric power. Such systems require proper component selection criteria and control strategies as these systems can operate in isolated and gridconnected mode. This paper aims to illustrate the design, control, and investigation of two different stand-alone distributed generation (DG) configurations based on proton exchange membrane fuel cell (PEMFC) and wind energy conversion systems (WECS). Apart from these stand-alone system configurations, the paper also investigates a gridconnected WECS-FC-based hybrid DG model in order to validate the design and control aspects of a typical gridintegrated hybrid system. A special emphasis is given to the effect of unbalance fault or a voltage sag in a grid-connected hybrid system. It is significant to state that the design of a hybrid energy system is also dependent on the control philosophy adopted. Thus, the typical control philosophy for interfacing inverter which is operating either in stand-alone or in gridconnected mode is also discussed in this paper. The above investigation studies assist the research community with the typical design calculations and also with the proposal of new fault ride-through (FRT) control schemes.