Hysteresis Current Controllers for Grid Connected Inverter: Review and Experimental Implementation

The purpose of this paper is to present a comparative study on basic hysteresis current controller techniques for grid connected inverters. Hysteresis current controllers are best known for robustness, fast error tracking, better dynamic response and ease of implementation than other controllers proposed in literature. To improve the power quality of grid connected inverter, different methods of hysteresis current controller are studied under dynamic conditions. An Analytical study has been carried out on the basis of Total harmonic distortion (THD) and maximum switching frequency. In this paper, single band hysteresis control (SBHC), double band hysteresis control (DBHC), modified double band hysteresis control (MDBHC) and variable band hysteresis control (VBHC) techniques are discussed. All the analytical and experimental results are compared with a constant hysteresis band. Simulation and hardware results are presented to validate the analysis and performance of controllers for steady state and dynamic condition.