Optimal Operation of Distribution Electronic Power Transformer Using Linear Quadratic Regulator Method

Subject Areas : Renewable energy

Mohammad Hosein  Rezaei ¹ (MSc/Islamic Azad University - Najaf Abad Branch)
Rahmatolah  Hooshmand ² (Associated Professor/ University of Isfahan)
Mohammad  Ataei ³ (Associated Professor/University of Isfahan)

Received: 2010-02-03 Accepted : 2010-07-20 Published : 2011-11-01

Keywords: state space model, Distribution electronic power transformer, linear-quadratic-regulator, dynamic performance,

Abstract :

Transformers perform many functions such as voltage transformation, isolation and noise decoupling. They are indispensable components in electric power distribution system. However, at low frequencies (50 Hz), they are one of the heaviest and the most expensive equipment in an electrical distribution system. Nowadays, electronic power transformers are used instead of conventional power transformers that do voltage transformation and power delivery in power system by power electronic converter. In this paper, the structure of distribution electronic power transformer (DEPT) are analized and then paid attention on the design of a linear-quadratic-regulator (LQR) with integral action to improve dynamic performance of DEPT with voltage unbalance, voltage sags, voltage harmonics and voltage flicker. The presentation control strategy is simulated by MATLAB/SIMULINK. In addition, the results that are in terms of dc-link reference voltage, input and output voltages clearly show that a better dynamic performance can be achieved by using the LQR method when compared to other techniques.