Power Factor Control of PV Generators in Local Distribution Networks using Fuzzy Logic Concept

ABSTRACT: One of the most important operational requirements for any electrical power network for both distribution and transmission level is voltage control. Many studies have been carried out to improve or develop new voltage control techniques to facilitate safe connection of distributed generation. In Saudi Arabia, due to environmental, economic and development perspectives a wide integration of photovoltaic (PV) generation in distribution network is expected in the near future. This development in the network may cause voltage regulation problems due to the interaction with the existing conventional control system. In a previous paper [1] a control system has been described using a fuzzy logic control to set the on-line tap changer for the primary substation. In this paper a new control system is proposed for controlling the power factor of individual PV invertors based on observed correlation between net active and reactive power at each connection. A fuzzy logic control has been designed to alter the power factor for the remote invertors from the secondary substation to keep the feeder voltage within the permissible limits. In order to confirm the validity of the proposed method, simulations are carried out for a realistic distribution network with real data for load and solar radiation. Results showing the performance of the new control method are presented and discussed. KEYWORDS: Grid connected PV system, Dnetwotk, Power factor, Fuzzy logic, Control. I.INTRODUCTION This paper presents an approach for solving the feeder voltage regulation problem in a local manner, with the goal of fulfilling the plug-and-play feature desired by manufacturers and regulatory bodies. The plug-and-play feature will enable customers to simply connect their PV systems to the distribution feeder, and through a fuzzy logic control (FLC) the power flow from the PV system through the inverters will be controlled to help maintain the feeder voltage level within limits at minimum cost. The chapter paper by the proposed controller objectives. The proposed controller design is based on FLC and the architecture is then presented. Test results of this system are shown to prove that the proposed controller can successfully regulate the voltage of a distribution feeder with PV systems connected to it. Finally the interaction between two controllers at the same feeder has been investigated and a simulation is carried out under MATLAB /Simulink environment to evaluate the stability of the control algorithm. II. CONTROL OF THE REACTIVE POWER OF PV GENERATION USING FLC Consider a voltage source V S ∟δ connected to a utility grid V G ∟0° through a coupling impedance Z=R+jX, as shown i