Simulation of Parallel Resonance Condition in Electrical Network Using EDSA

This paper covers the effects of parallel resonance in the Electrical Network due to Power Factor correction (PFC)/VAR compensation. Parallel Resonance can make entire electrical network unstable as THD (voltage) may rise upto 26% of fundamental (which is nearly seven to eight times of THD produced by the harmonic source) resulting in highly distorted Electrical wave. This will result in misfiring in UPS, Variable Frequency Drives, and Battery Charges. The Protection system may mal-operate due to resonance. The losses in various electrical equipments will increase, which will result in heating and ultimately premature failure of equipments. A typical Electrical network was modeled in EDSA (Electrical design software) and parallel resonance condition was simulated to analyze the effect of resonance on following:• THD on various busses in the electrical network • Impedance response with/without  the PFC • Distortion of  waveform at various buses • Corrective measures to avoid resonance due to PFC