【摘要】 架空地线因其不存在负载电流(除了很小的感应电流外),在冬季冰冻雨雪天气下较输电导线更易产生覆冰现象。而为了达到防雷效果,架空地线必须经铁塔可靠接地,这与在通电融冰工况下需使其对地绝缘相矛盾。文中针对所提出的一种220 kV防雷防冰灾架空地线系统,在简介其拓扑结构与工作原理基础上,根据该架空地线电缆参数及假设的融冰场景,通过计算直流融冰电流、电压,确定直流融冰电源的额定输出容量,并对该直流融冰电源的全桥模块化多电平换流器等核心部件的结构参数、元器件选型等进行了分析计算。最后在PSCAD平台上搭建了基于模块化多电平直流融冰电源的220 kV防雷防冰灾架空地线融冰仿真系统模型,对该直流融冰电源的控制性能进行了验证。更多还原

【Abstract】 The overhead ground wire is more likely to cause ice coating than the transmission line at freezing rain and snow condition in wither due to is absence of load current(except a very small inductive current). While,in order to achieve the lightning protection effect,the overhead line must be earthed reliably through iron tower,which is contradictory to its insulation to earth at power on and ice melting condition. In view of a kind of 220 kV lightning protection and anti-ice disaster overhead ground wire system proposed in this paper,the rated output capacity of the DC deicing power supply is determined on the basis of describing its topological structure and operating principle,in accordance with the cable parameter of overhead ground wire and the hypothetical deicing scenario as well as by way of calculating DC deicing current and voltage. The structure parameters and of such core elements as full-bridge modular multilevel converter of the DC deicing power supply and the element selection are analyzed and calculated. Finally,the deicing simulation system model of 220 kV lightning protection and anti-ice disaster overhead ground wire based on modular multi-level converter is set up on the PSCAD platform and the control performance of the DC deicing power supply is verified.更多还原