There has been continuing interest in designing Load Frequency Controllers (LFC) with better performance during the past three decades.
In an interconnected power system, power is being exchanged between areas over interconnecting tie lines. The desired objective is designing the area LFC to have some degree of control over tie-line power flow and frequency of individual areas, it is important to properly design the area LFC to improve both the system quality and reliability. The usual design theory to develop control laws on the basis of the linearized mathematical model is used. However, in the actual power systems, there exists nonlinearities such as parameters variations and generation rate constraint for generating units. Accordingly, Artificial Intelligence techniques are proposed, since those techniques are capable of dealing with nonlinear models.
Since, the application of centralized controllers results in several problems such as difficulties in data telemetry and computing capability limitations. Therefore, the local or decentralized controllers are preferred. From practical point of view, power system controllers should be of decentralized and intelligent type. To achieve the desired objective, a design of AI-Based Decentralized Load Frequency Controllers for Interconnected Power Systems will be proposed in this research work.
In this research two controllers are used to design a supplementary LFC for power systems. The first controller developed in this research is Optimal Design of Load Frequency Based- PID Control System Using Stochastic Particle Swarm Optimization (SPSO) Algorithm. The controller uses the frequency deviation of the system as a single feedback control signal. The reliability of the proposed controller is proved through a comparison of its response to those both of PID controller tuned by Ziegler second method and another PID controller tuned based on the frequency response analysis of the system. The second controller is Decentralized Load Frequency based PID Controller using SPSO for nonlinear power system control. The controller input is the frequency deviation of the system. The reliability of the proposed controller is proved through a comparison of its response to that of classical integral controller. The design procedures for the two controllers are used to propose new strategies for the LFC of the interconnected power system. Case studies are carried out to evaluate the effect of the secondary control loop on the behaviour of the system frequency. The two controllers are added one at a time to the model with the secondary control loop. The obtained results prove better system performance with the added controllers.
Finally, the two proposed controllers are applied to a multi-area system obtained by interconnecting two power systems. The obtained results proved that the controllers exhibit an excellent performance.
|
