Anew model-free control for load frequency control of interconnected power systems based on nonlinear disturbance observer

Load frequency control (LFC) is critical for ensuring power systems' stability, quality, and reliability by balancing power generation and consumption. Effective load frequency control is particularly important in multi-area, multi-source power systems where unpredictable load changes and system complexity increase the need for precise frequency regulation. This paper presents anew optimized model-free control approach for multi-area load frequency control (PSLFC) in an electrical power system. It utilizes an intelligent proportional- integral-derivative (iPID)-based model-free control and a nonlinear disturbance observer (NDOB). The control's primary goal is to achieve a balanced power exchange between tie-lines while taking into account the system's nonlinearities and disturbances. The proposed method consists of several key components. Firstly, the iPID controller injects desired values into the system. Secondly, using input and output signal data, the NDOB estimates and compensates for unknown dynamic behavior. Finally, particle swarm optimization (PSO) optimizes the parameter values. This approach offers a simple structure that can be easily implemented in areal system. The effectiveness of the controller is assessed via a power system that connects two areas. Each area has different types of conventional power generation units, such as thermal, gas, and hydraulic power plants. Moreover, the analysis takes into account non-linearities in the system, such as constraints on generation rates and deadband in governors, along with uncertainties in the system and fluctuations in the load. Simulation results in the MATLAB toolbox demonstrate the effectiveness of the proposed strategy. Additionally, sensitivity analysis of the controller is performed using various scenarios, highlighting its potential for improving the performance of multi-area LFCs.