الفهرس 
INTRODUCTION TO DISTRIBUTED GENERATIONOnly 14 pages are availabe for public view
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Abstract
The presence of Distributed Energy Resources and the subject of Distributed Generation (OG) are rapidly growing in modern distribution networks. Many of these resources use renewable energies, and many of them provide electrical energy in the form of dc voltage source. Consequently, the connection of such resources to the utility grid needs a DC/AC conversion stage. Voltage Source Inverters (VSI) are widely used for this application as they have a mature technology. These converters are usually connected to the utility grid through a simple inductor (L) filter to reduce the current harmonics injected to the grid. However, higher order filters, like inductor-capacitor-inductor (LCL) filters, can provide better harmonic attenuation and reduce the filter size at the same time.
In this thesis, different techniques for grid connected distributed generation through pulse width modulated (PWM) inverter are discussed. The discussion is accompanied by measuring the Total Harmonic Distortion (THD) value of the filter output current which is the main indicator during comparison between all control techniques in this thesis. In the first technique, a grid c’onnected hysteresis controller based inverter with an L-filter is discussed with a study of the effect of the filter inductance and the hysteresis band on the inverter output CUlTent distortion. In the second technique, a model of a grid connected inverter through L-filter is developed. Then, a grid connected proportional-integral (PI) controller based PWM inverter with an L-filter is discussed. In the third technique, a grid connected Dead-Beat controller based PWM inverter with an L-filter is discussed with a study of the effect of the filter inductance and the switching frequency on the inverter output current distortion. In the fourth technique, a grid connected Dead-Beat controller based PWM inverter with an LCL-filter is discussed. In the last technique, a state space model for the grid connected inverter with LCL-filter is discussed. Then, a state feedback controller with time delay is proposed and compared with the fourth method. The LCL-filter provides higher harmonic attenuation than the L-filter, but improper design of LCL-filter could lead to an unstable system.