A
phase perturbation based island detection
system for a distributed gird-connected
inverter is disclosed. The island detection
system comprises a
voltage controller, a multiplying unit, a summing unit, a current controller and a
pulse width modulation generator which are serially connected in sequence, wherein the input ends of the
voltage controller, the multiplying unit, the summing unit and the current controller are connected with
direct current bus voltage and set
direct current bus standard voltage respectively; the
pulse width modulation generator is for outputting four paths of triggering pulse signals used for driving a single-phase
H bridge inverter of a single-phase distributed gird-connected
power generation system; the island detection
system also comprises an orthogonal
signal generator, a synchronous phase-locking device, a
phase perturbation unit and a threshold value judging unit which are serially connected in sequence, wherein the input end of the orthogonal
signal generator is connected with the voltage end of a
point of common coupling of the single-phase distributed gird-connected
power generation system; and the output end of the
phase perturbation unit is connected with the input end of the multiplying unit. The phase perturbation based island detection system for the distributed gird-connected
inverter has rapidness in island detection, stability of the detection system, and possibility of being used as island detection standard, can satisfy demand on percent of pass of the
power quality, and has the important and actual application value in
safe operation of the distributed
new energy gird-connected
power generation system.