Harmonic resonance index and resonance severity estimation for shunt capacitor applications in industrial power systems

Despite the fact that shunt capacitors are widely used for voltage support, reactive power compensation, harmonic mitigation, and power factor improvement in power system networks, but harmonic resonance may occur between the system-capacitor and may have severe consequences. In this paper, a procedure to estimate the severity of harmonic resonance is formulated, and a harmonic resonance index (HRI) based on IEEE Std. 18-2012 for shunt power capacitor applications is introduced. A simple equation to express the harmonic resonance severity (HRSev) under different background harmonic voltage levels is proposed. A case study is employed to analyze the possibility and severity of harmonic resonance using the proposed formulations with various utility side's background voltage distortions. As a result, the proposed HRI formulation can facilitate its direct and quick use by industry to estimate the severity of resonance.