Performance study of distributed generation system in grid connected/isolated modes

Abstract

The Microturbine Generations (MTG) system is becoming one of the promising sources of Distributed Generation (DG) due to their fuel flexibility, reliability and power quality. Thus, the accurate model of MTG system is required for the grid connected operation and its perturbations. This article presents the performance study of MTG based DG system in grid connected, islanding and re-closed modes of operation. The developed model of MTG system includes a microturbine as prime mover, Permanent Magnet Synchronous Machine (PMSM) and power electronics interacting circuit along with control schemes. The MTG system uses the turbine speed to control the microturbine output power in comparison with the reference speed and shaft speed. The generated AC power is converted to DC using a passive rectifier and this DC power is inverted back to AC power to mach grid frequency. The DC link power is delivered to the grid, islanding load using a three phase voltage source inverter with Pulse Width Modulation (PWM) techniques. While delivering the DC link power to the grid and islanding load, the respective Active, Reactive Power (PQ) and Voltage Frequency (VF) control strategies are used for inverter operation. The detailed model of MTG system along with control schemes is developed using Matlab/ Simulink environment and the simulation results show the performance of MTG based DG system. From the simulation study, it is ascertained that, the developed model of MTG system can delivers the power to grid and isolated load significantly, by shifting the converter controller manually.