Analysis of Utility Protection Problems Associated with Small Wind Turbine Interconnections

This paper is an analysis of several protection coordination problems that may result from the integration of small wind turbines (less than 100 kVA) into the electric distribution system. Such problems include the characteristic contributions of fault current, fault detection ability, effects of increased short-circuit capacities, interaction with line reclosers, and islanding of dispersed generators. Examples are shown using actual utility line and equipment data. The wind turbines considered include small synchronous and induction generators as well as generation sources utilizing line-commutated or force-commutated inverter interfaces.