Ibraheem Nasiruddin

Optimal Automatic Generation Control of Asynchronous Power Systems Using Output Feedback Control Strategy with Dynamic Participation of Wind Turbines

Abstract—This article presents the design of optimal output feedback automatic generation control regulators for an interconnected power system with dynamic participation of doubly fed induction generator based wind turbines. The power systems consist of plants with hydro-thermal turbines and are interconnected via parallel AC/DC links. Efforts have been made to propose optimal automatic generation control regulators based on feedback of output state variables, which are easily accessible and available for the measurement. The designed optimal output feedback automatic generation control regulators are implemented, and the system dynamic responses for various system states are obtained considering 1% load perturbation in one of the areas. The dynamic performance is compared with that obtained with optimal automatic generation control regulators designed using full state vector feedback. The pattern of closed-loop eigenvalues is also determined to test the system stability.

Automatic Generation Control in an Interconnected Power System Incorporating Diverse Source Power Plants Using Bacteria Foraging Optimization Technique

Abstract This article presents automatic generation control (AGC) of a two-area interconnected power system with diverse energy sources using the bacteria foraging optimization technique. The control areas of interconnected power systems consist of hydro, thermal, and gas power plants. In this study, the proportional-integral-derivative (PID) structures of AGC regulators are designed for various case studies identified herein. An artificial intelligent optimization algorithm using the modeling behavior of E. Coli bacteria present in human intestines, is applied to tune the gains of PID structured AGC regulators. The closed-loop system dynamic response plots are obtained with designed AGC regulators for various power system models. The effectiveness of the proposed AGC regulators is demonstrated in the wake of a 1% step load disturbance in one of the control areas. It has been shown that the system dynamic responses subject to a step load disturbance are superior over other power plant combinations in a control area with only thermal and gas power plants participating in the AGC schemes, and it is sluggish/poor when only hydro power plants participated in the AGC scheme as one of the diverse sources in the power system.

A More Realistic Model of Centralized Automatic Generation Control in Real-time Environment

Abstract In this article, a more realistic model of centralized automatic generation control is proposed. Conventional centralized control model does not consider the effect of communication delays between the control center and generating units of the plant. These delays degrade the dynamic performance of automatic generation control or may even lead to unstable system. The proposed model incorporates the effect of these communication delays present in an automatic generation control system. The global controller has been developed for the proposed centralized control model. This global controller requires information of all states of the power system model. The proposed model has been investigated in the real-time environment, done with the help of three personal computers connected in series by Ethernet cables, called the real-time three-personal computer system. The novelty of this is that it is maintenance free, robust, and negligible in cost compared to real-time simulator kits available in the market. In summary, the proposed model of centralized automatic generation control is more realistic, incorporates the effect of communication delays, and investigated in the real-time environment. A novel real-time simulator (real-time three-personal computer system) developed is very cost effective. The results of proposed centralized control model are compared with the conventional centralized control model.

Optimal AGC regulator for multi-area interconnected power systems with parallel AC/DC links

Abstract The problem of simultaneous tuning of the automatic generation control (AGC) regulator’s gains of multi-area interconnected power system is carried out in this manuscript. Based on the types of area interconnections, a power system model consisting of reheat turbines is investigated by two test cases for the AGC study. In one of the test case AC link is used as area interconnection, whereas the parallel combination of AC/DC links is used as area interconnection in other test case. Each test case control area is consisting of plants with reheat thermal turbines. Genetic algorithm (GA) is used to globally optimize the gains of proportional integral-based AGC regulators with simultaneous optimization of frequency bias coefficient and tie-line power flows. The dynamic response curves are obtained for various system states with the implementation of designed GA-based AGC regulators considering 1% load perturbation in one of the areas. The conventional AGC regulators are also developed using the popularly known Ziegler–Nichols technique. The investigations carried out demonstrate the superiority of proposed regulators over the conventional AGC regulators. The incorporation of DC link in parallel with AC link as an area interconnection has also exhibited favorable effect on dynamic response of the system.

Hybrid evolutionary algorithm based fuzzy logic controller for automatic generation control of power systems with governor dead band non-linearity

Abstract A new intelligent Automatic Generation Control (AGC) scheme based on Evolutionary Algorithms (EAs) and Fuzzy Logic concept is developed for a multi-area power system. EAs i.e. Genetic Algorithm–Simulated Annealing (GA–SA) are used to optimize the gains of Fuzzy Logic Algorithm (FLA)-based AGC regulators for interconnected power systems. The multi-area power system model has three different types of plants i.e. reheat, non-reheat and hydro and are interconnected via Extra High Voltage Alternate Current transmission links. The dynamic model of the system is developed considering one of the most important Governor Dead Band (GDB) non-linearity. The designed AGC regulators are implemented in the wake of 1% load perturbation in one of the control areas and the dynamic response plots are obtained for various system states. The investigations carried out in the study reveal that the system dynamic performance with hybrid GA–SA-tuned Fuzzy technique (GASATF)-based AGC controller is appreciably superior as compared to that of integral and FLA-based AGC controllers. It is also observed that the incorporation of GDB non-linearity in the system dynamic model has resulted in degraded system dynamic performance.

Optimal Output Vector Feedback Control Strategy for Wind Power Systems

Abstract This article presents the design of optimal output feedback controllers to enhance the dynamic performance of wind turbine generator supplying an infinite bus through transmission line. Efforts have been made to propose optimal regulators based on feedback of output state variables, which are easily accessible and available for the measurement. The designed optimal output feedback controllers are implemented in the wake of step disturbance in the system. The system dynamic responses and pattern of closed loop system eigenvalues for various system states are obtained with the designed optimal regulators to investigate the system dynamic performance. The investigations of the results obtained reveal that the reduction in system states used for feedback has resulted in degradation of system dynamic performance. However, for a particular set of output variables used as feedback; five states are used for feedback for an eighth order original system. The system dynamic performance is the same as offered by optimal controllers based on full state vector feedback control strategy.

Model Order Reduction of Two Area Hydropower System Using Mixed Method

The complexity of power system models used for operation and control analysis has been increasing due to their operation in interconnected fashion. This paper presents a novel approach to develop reduced-order models of complex and large interconnected power system models by using mixed method of model order reduction technique. A state-space model of automatic generation control (AGC) system of a two-area interconnected power system model consisting of hydropower plants is developed. It is an original system of 11th order which is approximated to a reduced model of 3rd order. Validation of reduced-order model is done by comparing step response of original model with reduced-order model. The investigations of step responses show that the 3rd-order model is a good approximation of original model as far as its dynamic responses are concerned.

Real-time automatic generation control considering communication delays using linear matrix inequalities

This paper investigates the effect of communication delays on dynamic performance of automatic generation control (AGC) of thermal power system. Field data of power system i.e. frequency and tie-line power deviations are transmitted over the dedicated data links to control centres of the plant. Sometimes these data links introduce communication delays in between and degrade the dynamic performance of the AGC system. These communication delays have not been considered in the existing models of AGC system. This paper, considers the effect of these communication delays and presents a realistic model for AGC system. The global controller has been designed for the centralized control scheme using linear matrix inequalities (LMIs) technique. The system has been studied in real-time environment, using three personal computers (PCs) connected in series named as real-time three PC system (RTTPS).