An intelligent current limiter and Zero Active Power Injection algorithm for microgrid voltage support

This paper presents an ancillary control scheme to be used by a generic Distributed Generator (DG) for voltage support. It consists of an intelligent current limiter coupled with a Zero Active Power Injection (ZAPI) algorithm. The ZAPI algorithm can ensure voltage support without effecting the nominal real power output of the distributed generator. The intelligent current limiter ensures that the current demanded by the voltage support scheme does not effect the angle or magnitude of currents associated with DG real power injection. The control scheme is able to be utilised by parallel inverters as it is based on open loop current control and direct power flow solutions. SABER®simulations are provided to show the operation of the control scheme for an individual inverter and two parallel inverters whilst grid connected.