Harmonic-Constrained Optimal Power Flow

Modern power systems incorporate renewable energy resources as distributed generation to reduce cost and improve reliability and efficiency. Power electronic converters are often utilized to couple renewable resources. However, power electronic devices create harmonic distortions, which cause power quality and device reliability issues. In this thesis, a new dispatch tool that promotes renewable energy while restricting harmonic distortions is developed. This tool combines system harmonic models with optimal power flow, and provides the optimal dispatch with limited harmonic distortions. Frequency coupling matrices are adopted as converter harmonic models. Relaxation is applied to transform the optimization problem to a semidefinite program, which can be effectively solved using a commercially available software. Numerical tests on two IEEE feeder networks verify the model and demonstrate that the system operator can reduce system harmonic distortions at small or zero additional generation cost by dispatching the renewable energy resources according to the new method.M.A.S