A high voltage capacitor element model

High voltage capacitors are becoming ever more prevalent on modern electrical power networks, as they offer simple means of power factor correction and voltage support, and are inherent to modern power electronic converter designs. Large capacitor banks comprise many modules, each of which contains an array of individual elements, across which voltage stresses and thermal conditions are shared. A module’s partial degradation due to short-circuited elements can increase stresses on the insulation of those that remain, sometimes leading to cascading element failure. This paper presents a high voltage capacitor model, and then explores the distribution of voltage under healthy and short-circuit scenarios. It shows voltage distributions between elements within a capacitor module have non-linearity due to a module’s geometry, and are affected by series element failure.