Wide Range Reactive Power Compensation for Voltage Unbalance Mitigation in Electrical Power Systems

In this work, a wide range of reactive power compensation is achieved for voltage unbalance mitigation in 500 km electrical power systems. An Optimal Control Technique (OCT) is proposed to encompass the unbalance load changes at a wide range of Voltage Unbalance Factor (VUF), between 3.33% and 12.4601%, and to minimize it to an acceptable value (at average less than 2%). The technique uses a combination of Particle Swarm Optimization (PSO) and Artificial Neural Networks (ANN) in three stages. In the first stage, the PSO finds the optimal firing angles of the Thyristor Controlled Reactor (TCR) and the optimal number of bank capacitors for the Thyristor Switched Capacitor (TSC) to restore the voltage balance. In the second stage, the voltage unbalance evaluations obtained by the PSO algorithm are used to train the ANN. In the third stage, the ANN is connected to the system to control and overcome the voltage unbalance problem accurately and quickly. Results are compared with other techniques available in the literature to confirm the superiority of the OCT performance. Furthermore, a laboratory model for the electrical power system is built and the proposed OCT for real voltage unbalance mitigation is validated.