Optimal Scheduling of LTC and Shunt Capacitors in Large Distorted Distribution Systems Using Evolutionary-Based Algorithms

The optimal scheduling of load tap changers (LTCs) and switched shunt capacitors for simultaneously minimizing energy loss and improving voltage profile while taking harmonics into account is performed using evolutionary-based algorithms (EAs). The proposed algorithm is capable of optimizing large distribution systems with different types of nonlinear loads. The decouple approach is employed for harmonic power-flow calculations, while two EAs are developed to determine the load interval division and near-optimal schedule. The inclusion of harmonics provides the optimization benefits while maintaining the acceptable distortion levels. The scheduling is carried out for the IEEE 123-bus with 14 shunt capacitors and 12 nonlinear loads. The main contributions are inclusion of harmonics in the optimal scheduling problem and its application to large distribution systems with multiple nonlinear loads.