Adaptive Hysteresis Current Control of Dc-ac Inverter in a Grid Connected Pv System

6.1 INTRODUCTION The previous chapters have discussed the development of the MPPT algorithm and the control of the DC-DC converter in a standalone PV system. A grid-connected PV system is composed of a photovoltaic array, DC-DC converter, DC link capacitor, single phase DC-AC inverter, filter inductor, power grid, and non-linear load. The grid interconnection of a PV power generation system has the advantage of more effective utilization of the generated power. The Grid interconnection of PV systems is accomplished through the inverter. The Grid-connected inverter is the critical interface of a photovoltaic array connected with the power grid. Pulse width modulation (PWM) is the most popular control technique in voltage-source inverters. Compared to the PWM converters, the current-controlled PWM has several advantages. It has lesser distortion and lower harmonic noise. This chapter deals with the development of adaptive hysteresis current control techniques for the DC-AC inverter, in order to provide a constant switching frequency with less harmonic content. The simulation results obtained, using the proposed current control technique, are presented. The hardware implementation of the proposed inverter current control algorithms using Xilinx spartran-3 FPGA, is also presented.