CAJ | 학술논문

针对低压微电网在不同接地方式下运行的安全稳定性问题,提出了典型微网的接地方案.基于国家/行业标准,结合理论分析和实践应用比较,对低压微电网主变压器接地方式、微源接地方式、低压微网系统接地方式分别进行了比选,给出了不同情况下各种接地方式的适用条件和场合.结合微网系统特点得出了适用低压微网的接地方案,即主变优选用D,yn11连接组别,中性点有效接地,微源并网时中性点不接地,孤岛时仅主电源中性点接地.整个微网系统采用TN-S/TN-C-S与TT混合接地方式,微源和三相用户采用四级开关,单相用户采用两级开关.
침대저압미전망재불동접지방식하운행적안전은정성문제,제출료전형미망적접지방안.기우국가/행업표준,결합이론분석화실천응용비교,대저압미전망주변압기접지방식、미원접지방식、저압미망계통접지방식분별진행료비선,급출료불동정황하각충접지방식적괄용조건화장합.결합미망계통특점득출료괄용저압미망적접지방안,즉주변우선용D,yn11련접조별,중성점유효접지,미원병망시중성점불접지,고도시부주전원중성점접지.정개미망계통채용TN-S/TN-C-S여TT혼합접지방식,미원화삼상용호채용사급개관,단상용호채용량급개관.
Different grounding modes in low-voltage microgrid bring a series of security and stability issues. To solve these problems, a grounding arrangement for low-voltage microgrid is proposed. With deeply researching national standards and electric standards, combined with the analysis of theory and application, the grounding modes of the main transformation, distributed generation and low-voltage microgrid system are compared respectively, and applicable condition and occasion of various grounding modes in different circumstances are given. Finally, grounding arrangement in the classical microgrid is given by contacting with character of the microgrid, i.e. the main transformer selects D, yn11 connecting group grade preferentially with neutral grounding. The neutral points of distributed generations are ungrounded when microgrid is on-grid, and only the neutral point of main distributed generation turn into grounded when microgrid is off-grid. The whole microgrid system adopts mixed grounding mode with TN-S, TN-C-S and TT by applying four-grade switch for distributed generations and three phase loads and two-grade switch for single phase loads.