16th International Middle- East Power Systems Conference -MEPCON'2014 Ain Shams University, Cairo, Egypt, December 23 - 25, 2014 A REAL TIME SIMULATION BASED NEW ROBUST LOAD FREQUENCY CONTROL SYSTEM G. Shabib Tarek Hassen Mohamed, Hossam Ali Department of Electrical Engineering Department of Electrical Engineering, Control & Robotics Laboratory Faculty of Energy Engineering Faculty of Energy Engineering Aswan university, Aswan, Egypt Aswan University, Aswan, Egypt, P.O. Box: 81528 E-mail: gabershabib@yahoo.com e-mail:tarekhie@yahoo.com e-mail:hossam_ali@aswu.edu.eg Abstract – This paper presents real time simulation to analyze the behavior of discrete controller for a single area power system. A new load frequency control (LFC) design using the coefficient diagram method (CDM). The CDM technique has been designed such that the effect of the uncertainty due to governor and turbine parameters variation and load disturbance is reduced. A frequency response dynamic model of a single-area power system is introduced, and physical constraints of the governors and turbines are considered. The real time simulation provides a quick solution for prototyping new functions in different types of industrial processes and devices controlled with a complex distributed control system. Digital and Real time simulations for a single area power system are provided to validate the effectiveness of the proposed scheme. The results show that, with the proposed CDM technique, the overall closed loop system performance demonstrated robustness in the face of uncertainties due to governors and turbines parameters variation and loads disturbances. A performance comparison between the proposed controller and a classical integral control scheme is carried out confirming the superiority of the proposed CDM technique. Index Terms - Load frequency control, integral control, coefficient diagram method, Real time simulation. I. INTRODUCTION oday, control system designers try to apply different control algorithms in order to find the best controller parameters to obtain the best solutions. Some of these methods are very successful for special cases while unsuccessful for other general applications. In LFC problem, area load change and abnormal conditions lead to mismatches in frequency and scheduled power interchanges between areas. These mismatches have to be corrected by the LFC system. LFC objectives, i.e. frequency regulation and tracking the load demands, maintaining the tie- line power interchanges to specified values in the presence of modeling uncertainties, system nonlinearities and area load disturbances, determine the LFC synthesis as a multi-objective optimization problem [1, 2]. The fixed parameters controller, like an integral controller or a PI controller, is widely employed in the LFC application. Fixed parameters controllers are designed at nominal operating points and may no longer be suitable in all operating conditions. For this reason, adaptive gain scheduling approaches have been proposed for LFC synthesis [3,4]. This method could to overcome the disadvantages of the conventional PID controller, but actually it faces some difficulties, like the instability of transient response as a result of variations of the system parameters, in additionally, It is Impossible to obtain accurate linear time invariant models at variable operating points [3] . Fuzzy logic controllers have been used in many reports for LFC design in a two area power system [5]. The applications of artificial intelligence and genetic algorithms in LFC have been reported in [6]. in spite of these efforts, it seems some other elegant techniques are needed to achieve a desirable performance. Recently, several optimal and robust control strategies have been developed for LFC synthesis according to change of environment in power system operation[7]. These methods show good dynamic response, but, due to increasing the complexity and change of the power system structure, the robustness in the presence of modeling uncertainties and system nonlinearities was not considered, so, other elegant techniques are needed to achieve a desirable performance. On the other hand, a new robust control strategy coefficient diagram method (CDM), which is an algebraic approach applied to a polynomial loop in the parameter space, where a special diagram called coefficient diagram is used as the vehicle to carry the necessary design information, and as the criteria of good design. [8]. The CDM is fairly new in the application of LFC, but its basic philosophy has been known in industry and in control community for more than 40 years with successful application in servo control, steel mill drive control, gas turbine control, and spacecraft attitude control [9]. Our goal in this paper is to use the real time simulation which can simulate the impact of suddenly changing in load demand and the parameters uncertainty of the power systems without expenses. Because the on-site testing of power system is costly, time consuming so, experimental works with real-time simulator allows properly the investigation of the dynamics characteristics of a single area load frequency control system with high accuracy[10]. In this paper, the load frequency control for a single area power system has been developed based on the CDM technique. The parameters of the polynomials of CDM technique have been designed based on the dynamic model of the single area power system. The effects of the physical T