Unsymmetrical fault correction for sensitive loads utilizing a current regulated inverter

Many industrial applications involve loads which are very sensitive to electrical disturbances in the supply. These instances involve both various types of voltage unbalance as well as more series disturbances such as symmetrical and asymmetrical faults. This paper proposes a voltage unbalance and an unsymmetrical fault correction technique for a three phase load utilizing an industry-standard current regulated voltage source inverter by connecting it in parallel to the associated three phase transformer. The inverter regulates the current for the load and never allows the current to exceed to a prescribed value under any type of unsymmetrical condition.