Automatic generation control of interconnected power system for robust decentralized random load disturbances using a novel quasi-oppositional harmony search algorithm

An effort is made in this paper to discuss the real-time problem of interconnected power system for resistance to random and rapid changes of small step load perturbation (SLP) in connection with automatic generation control (AGC). Rapid changes of loads, for a continuous period of time, always create problems in the benefits of optimum AGC performance. In view of this, a continuous nature of load profile is designed for its implementation in real-time application of AGC. In such case, the point of concern is to closely examine the frequency deviation and the behavior of tie-line power flow profiles within the control areas. To overcome these consequences, a novel quasi-oppositional harmony search (QOHS) algorithm based proportional integral derivative (PID) controller is proposed along with filtering technique. The test system under consideration is a three-area power system with two generating units (non-identical capacity) in each area having an appropriate generation rate constraint (GRC). Importance of considering the physical constraint (like GRC) is demonstrated by examining the closed loop performance of the studied power system model. The performance of the proposed QOHS algorithm is verified by comparing the obtained dynamic responses to those offered by the imperialist competitive algorithm for the same test system. In the final phase of investigation, the total load changes of all the three control areas are also considered for the purpose of analyzing the saturation and non-linearity effects of turbine. It may be apprehended from the simulation results that the proposed QOHS based PID controller is more efficient to minimize the effect of continuous SLP. The proposed QOHS algorithm shows the feasibility of the approach and is able to regain its steady-state operation for such load perturbation profiles. (C) 2015 Elsevier Ltd. All rights reserved.