Intelligent Transformer Tap Controller for Harmonic Elimination in Hybrid Distribution Network

Renewables are incessantly increasing in the distribution network to supply the power demand and reduce the dependency on fossil fuel power plants. The power output of renewables depends on weather conditions. Variation in voltage due to changing climate is one major issue with renewable energy sources. In such a situation, maintaining the constant voltage poses extra duty on the distribution transformer. The PWM AC choppers are most often employed with on-load tap changers (OLTC) to regulate the voltage of distribution feeders. However, these choppers introduce undesirable harmonics in the network due to their non-optimal firing angles. This paper presents an intelligent technique to operate the AC choppers for harmonic elimination in a hybrid (solar/wind) distribution network. Various optimization algorithms such as PSO, GWO, ALO, and DE are tested on the system with optimal firing angles of the chopper. The network performance is assessed considering various parameters such as output voltage, total harmonic distortion, and voltage/current harmonics in the network. The efficacy of PSO, GWO, ALO, and DE algorithms are presented and discussed. The best-suited algorithm, which gives the noticeable reduction in voltage and current harmonics with an enhanced magnitude of the output voltage, is presented.