Phase perturbation based island detection system for distributed gird-connected inverter

Abstract

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.

Description

technical field [0001] The invention relates to an island detection system. In particular, it relates to a distributed grid-connected inverter islanding detection system based on phase disturbance. Background technique [0002] Considering the advantages of clean, non-polluting and abundant reserves of new renewable energy, the structural adjustment of the energy industry is widely emerging around the world. In the long run, the development of new renewable alternative energy sources and the improvement of clean power supply will have substantial promotion significance in terms of technological improvement, environmental protection, and economic development. [0003] The distributed power generation system developed by leading renewable energy such as solar energy, wind energy, and biomass energy aims to provide users with high-quality, clean, and efficient power resources. Distributed power generation system has achieved new development in the renewable electric energy in...

AI Technical Summary

Problems solved by technology

If the frequency of the disturbance signal is too high, the effect of the local load quality factor will be amplified, making it difficult to detect isolated islands; if even-order harmonics are used as disturbances, you have to face the trouble that even-order harmonics are difficult to eliminate

Throughout most of the literature related to islanding detection, few scholars have proposed a new method for islanding detection in combination with voltage synchronization technology.

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