Improvement of Load Frequency Control for Two-Area Modern Power Systems Involving Renewable Energy Sources Using a Novel Cascade Controller

Abstract

Abstract Recently, the importance of frequency and voltage stability in interconnected power systems has been raising with increasing energy demand and participation of renewable energy sources (RESs) in electric power systems. In this context, high quality, reliable, continuous and stable electrical power transmission should be made to the consumer in modern power systems. The incongruence between the power generation and load demand in sudden load changes in power systems cause undesirable oscillations in the frequency and tie-line power between generation areas. The controllers used to suppress these oscillations in load frequency control (LFC) must operate satisfactorily in line with the desired system criteria. This study proposed a powerful cascade controller structure based on the combination of the PID and FOPID controllers with fractional derivative filters (PID-FOPIDFF) to meet the desired system criteria. Moreover, the parameters of the proposed controller structure are adjusted using Slime Mold Algorithm (SMA), Gradient-based optimizer (GBO), Hunger games search (HGS), weighted mean of vectors (INFO), and RUNge Kutta optimizer (RUN) algorithms. The SMA method offers a percentile decrease of 48.5399%, 119.0483%, 155.0614%, and 200.5109% in comparison to the outcomes of the HGS, GBO, INFO, and RUN algorithms for the ITAE value utilized as the objective function in the optimization process of the proposed PID-FOPIDFF controller. The performance of the proposed controller was compared with the performances of seven different controllers most used in the literature. The PID-FOPIDFF controller, which can respond quickly and dampen frequency and power oscillations, guarantees that system performance will be improved. Three different test systems including combinations of photovoltaic (PV), fuel cell (FC), electrolyser, thermal, hydropower, gas and wind energy systems, and the TCPS from FACTS devices are used to confirm the effectiveness of the method. The simulation results reveal the advantages of the proposed PID-FOPIDFF controller over the commonly used controllers. The robustness of the proposed controller structure is confirmed by the simulation study findings, which included various load and system parameter changing scenarios.