A Modified SMS Islanding Detection Technique for Reduced Non Detection Zone

Islanding detection plays a crucial role in grid connected distributed generation systems. In literature different types of Islanding detection techniques, categorized as active, passive and hybrid are discussed. Slip mode frequency shift islanding detection method (SMS IDM) is a popular active islanding detection method. Though the technique is able to detect islanding in most of the loading conditions, it has Non -Detection Zone (NDZ) for loads with high quality factor and low real power consumption. This paper proposes an active islanding detection technique which is motivated from SMS IDM, but it uses reactive power output of inverter instead of the phase angle as a function of frequency of the voltage at the Point of Common Coupling(PCC). It has been shown that the proposed technique is independent of the active power consumption of the load and works for all types of loading conditions. Selection of parameters for the proposed technique is also discussed in this paper. Simulations have been carried out in MATLAB/Simulink for different types of loading conditions to validate the proposed technique.