中压电网中性点接地方式分析与探讨外文翻.doc

中压电网中性点接地方式分析与探讨--外文翻译 A1.2 Medium-voltage power grid neutral grounding Analysis and Discussion 1OVERVIEU An overview pressure to 35KV,10KV,6KV three grid voltage voltage applications more widespread, all its non-neutral grounding system, but with the development of the distribution network, In particular, the introduction of cable lines of the increasing number of users, which makes single-phase current to increase capacitance, lead to within single-phase power grid fault for the accident expansion. Chinas electrical equipment design specification requirements if 35KV single-phase power grid to more than capacitive current 10A, If grounding grid 3KV-10KV capacitive current greater than 30A. need to use neutral through resonant grounding, Urban Planning and Design Network Guide implementation of section 59 provides that 35KV,10KV City Network, When the cable lines longer, larger capacitive current system, can be used in resistance mode. By the right medium voltage power grid neutral grounding nations of the world have different viewpoints and operating experience, in our case, In this theory, engineers discussing the hot issues in the medium voltage power grids, in which sexual point of grounding, has caused many concerns facing the direction of development decision-making. 2. Two different neutral grounding and the reliability of electricity supply 1916 invention of the Petersen circle and in 1917 the first plant in Germany Pleidelshein so far put into operation, 84 years of history, Experience shows that its widely used in medium voltage power network in the world with Germany, China, the former Soviet Union and countries such as Sweden and China have long-standing network this way, significantly enhanced the medium voltage grid safe and economic operation level. Neutral used by the fire Coil grounding in the system to single-phase, the flow then the current smaller location, Its characteristics are single-phase lines to occur, may not immediately