Harmonic resonance assessment in low voltage distribution system

In a power system, due to proliferation of power electronic equipments that produce harmonic current, harmonic resonance can occur when the system natural frequency closes or corresponds to the frequency of harmonic current source. This paper presents a power system simulation of medium/low voltage system, which contains 22 kV/400 V transformer, harmonic load (6 pulse converter), and low voltage fixed capacitor. By using DIgSILENT PowerFactory Program, the harmonic component of capacitor current, system response and harmonic impedance are presented. Assessment of harmonic resonance effect on low voltage capacitor are considered with IEEE Std. 1036-1992 guide for application of shunt power capacitor which provides limitations of capacitor on voltage, current and reactive power for determination of the maximum allowable harmonic levels. Moreover, the assessments of harmonic distortions are also compared with IEEE Std. 519-1992.