Impact of distributed generation and series compensation on distribution network

In this paper, the voltage profile and power quality issues of a distribution network with distributed generator (DG) and series compensation are investigated. A doubly-fed induction generator (DFIG)-based DG unit and a series capacitor (SC) and a thyristor-controlled series capacitor (TCSC) are considered for the analysis. Series compensation is implemented to reduce voltage drops in the line and feeder, and to minimize the reactive power mismatch caused by integrating DFIG units. The converter of the DFIG is modeled as an unbalanced harmonic-generating source and the load is modeled according in IEC standard 61000. The impacts of DG and series compensation on voltage profile, stability margin, dynamic stability and harmonic distortion of a distribution network are investigated in detail. Case studies are conducted on a widely used 15-bus distribution network in the DIgSILENT PowerFactory environment. The simulation results demonstrate that series compensation can enhance the collapse margin, reduce bus voltage sensitivity to reactive power and also improve both dynamic and transient voltage stabilities.