A practical harmonic resonance guideline for shunt capacitor applications

Shunt capacitors are extensively used in power systems for voltage support and power factor correction. The proliferation of harmonic-producing loads significantly increases the possibility of system-capacitor resonance. As a result, a practical and easy-to-use procedure to estimate the severity of harmonic resonance is of good interest to industry. The objective of this paper is to present such a method. The paper first proposes a harmonic resonance index. By taking into account the IEEE harmonic limits and the capacitor loading limits, a harmonic resonance chart is developed. A detailed harmonic analysis of the system is needed only if the system condition is located in certain regions of the chart. Examples are given to show how the possibility and severity of harmonic resonance can be estimated using the proposed guideline.