International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Impact Factor (2012): 3.358 Volume 3 Issue 11, November 2014 www.ijsr.net Licensed Under Creative Commons Attribution CC BY A Novel Method to Improve the LFC in Single Area and Two Areas Power System Using PI Controller K. Vijaya Kumar 1 , V. Lakshma Naik 2 , A. Suresh Babu 3 1 M. Tech. Scholar, Department of Electrical and Electronics Engineering, JNTU, Anantapur, India 2 Co-Author 3 Mizan-Tepi University, Ethiopia Abstract: This paper presents A novel method to improve the load frequency control in single area and two area power system. This means the load variation on a power system which gives the frequency drift from its nominal value. This gives the quality of electric power, reliable and good, because for minimizing the fluctuations of frequency. This paper is mainly focused on technical issues associated with load frequency control (LFC) in single area and two area power system. In this paper shown the dynamic response of the load frequency control using MATLAB/SIMULINK software. These results are shown and there is no steady state error in frequency fluctuations has been implemented. Keywords: Two area, Tie-line power, LFC, MATLAB, SIMULINK 1. Introduction The main objective of the power system is to maintain the continuous supply of power with good quality and reliable, to all the consumers in the system. The load frequency control is very important for the right operation of interconnected power system. It requires maintenance of a balance between the instantaneous active power produced and consumed. If the production of electric power is larger than consumption, the frequency increases and vice versa. Hence, load frequency control is used to maintain the system frequency at nominal value for supplying good quality power to consumers. The load demand keep on increasing and decreasing during steady state operation of power system. Irrespective of the load change, the tie line floe should be maintained at even value. This requires the manipulation of the operation of valves of the governor with a suitable control strategy so that constant speed can be maintained, and the real power output of the generator be controlled. Hence, an integrator is added, which is automatically adjusts the generation to restore the frequency to its nominal value. Thus the control of real power output of electric generators in this way is termed as “Automatic generation control (AGC)”. AGC is basically used to divide the loads among the system, such as to achieve maximum economy and accurate control of the tie line power interchange while maintaining a reasonably uniform frequency during normal period. The frequency control in an inter connected system is accomplished through two automatic controls: primary control and secondary control. The main objective of primary control is to stabilize the system frequency at stationary value following a disturbance, and to maintain the tie line power control areas at scheduled values by adjusting the output of some generators. Secondary control is basically used for automatic restoration of the frequency and the power exchanged between the different areas of the interconnected systems, at their scheduled values (i.e. ∆f = 0, ∆P i = 0), taking into account control program. Also, their performance deteriorates with the increase in the complexity of the system. Hence, AGC has an importance and is increasing their demand in the inter connected power system. There is a number of control strategies were achieve by the better performance. Because of this non linearity of power the system parameters and system is suggested by around an operating point. PI control is more advantage and is widely used[1]. 2. Theory of Load Frequency Control 2.1 Frequency Response in Primary Control The power system consists of a variety of loads of electric devices. Some are sensitive to frequency changes and some are not. The sensitivity depend on composite of the characteristics of speed-load all the devices. The speed load characteristics of a composite load is given by ΔP e = ΔP L + DΔω (1) Where, ΔP L = Non frequency sensitive load change DΔω = Frequency sensitive load change D = percentage change in load divided by the percentage change in frequency (Damping factor). When the system frequency drifts from nominal value (50HZ), the frequency sensitive components in the power system react to this change and the effective load system changes. This process is called load damping. Also, when the sudden increases in the electrical load, the turbine speed and hence the generator frequency begins to decreases. The speed is changes and is sensed by governor and it adjusts the turbine input valve to change mechanical power output so as to takes steady state. This can be done with the help of governed speed droop R, which is actually the feedback loop gain in the governor. The speed drop is defined as R = Δω / ΔP pu (2) Where, Δω = speed deviation ΔP = output power [2] Paper ID: OCT141233 1440