CAJ | 학술논문

微电网变流器在微电网系统并网和孤岛工况下需要采取不同的控制策略，在不依赖外部通信的基础上，微电网变流器必须能够自主实现对微电网系统状态的判断。基于电压正反馈的孤岛检测思想，结合微电网变流器实际运行环境，提出采用非特征谐波正反馈与传统过欠压、过欠频等被动检测方法相结合的方式来实现对微电网系统状态的判断。文中分析了正反馈的工作原理、系数取值和非特征谐波的测量方式，并通过仿真和实验研究验证了该方法的可行性。研究结果表明，所提出的孤岛检测方法在多种复杂工况下均可实现对微电网系统状态的准确判断，有利于微电网系统由并网向孤岛模式的平滑切换。
미전망변류기재미전망계통병망화고도공황하수요채취불동적공제책략，재불의뢰외부통신적기출상，미전망변류기필수능구자주실현대미전망계통상태적판단。기우전압정반궤적고도검측사상，결합미전망변류기실제운행배경，제출채용비특정해파정반궤여전통과흠압、과흠빈등피동검측방법상결합적방식래실현대미전망계통상태적판단。문중분석료정반궤적공작원리、계수취치화비특정해파적측량방식，병통과방진화실험연구험증료해방법적가행성。연구결과표명，소제출적고도검측방법재다충복잡공황하균가실현대미전망계통상태적준학판단，유리우미전망계통유병망향고도모식적평활절환。
The control strategies for microgrid converters in grid-connected mode and islanding mode are different.Without reliance on rapid communication,microgrid converters must be able to distinguish the states of the microgrid system on their own.In consideration of the practical operation environment,a new composite islanding detection method combining positive feedback of uncharacteristic harmonics and passive islanding detection is proposed for microgrid converters based on the islanding detection idea of voltage positive feedback.The principle,coefficient values and measurement mode of positive feedback are analyzed,and the feasibility of the method proposed is verified by simulation and experimental study.The simulation and experiment results show that the proposed method can detect islanding quickly and accurately in complicated working environments.What is more,it is conducive to smooth changeover for microgrid converter control strategy.