摘要
电力系统Y0/△-11(或Y/△-11)变压器低压(或复合电压)启动过电流保护中采用的低电压启动传统方案为保护安装侧及另一侧的两侧线电压"或"门启动。所提出的低电压启动新方案为采用保护安装侧的单侧相电压及线电压"或"门启动。经计算分析:变压器任一侧两相短路,新方案与传统方案动作灵敏度相同;变压器高压侧单相接地短路,Z 0 Z 1 1.5时传统方案只能勉强动作,Z 0 Z 1 1.5时传统方案拒动(Z0、Z1为系统零序、正序阻抗),而不管Z 0 Z 1为任何值新方案都极灵敏动作。新方案所需保护电压通道远少于传统方案。
The traditional program of over current protection in low-voltage （or composite voltage） start of Y0/△-11（or Y/△-11） power transformer is ＂or＂ gate start of two-sides line voltage. We propose a new program which is the ＂or＂ gate start of the phase voltage and line voltage only at the installed side. After analysis and calculation, we conclude that they have the same sensitivity when the two-phase short circuit happens at either side of a transformer. When a single-phase ground short circuit happens at the high voltage side, if Z0∑/Z1∑ 〈 1.5, the traditional one could barely run, if Z0∑/Z1∑〉 1.5, it refuses to run （Z0∑and Z1∑ are zero-sequence impedance and positive-sequence impedance of the system respectively）. The new program runs very sensitively regardless of the Z0∑/Z1∑ value and it needs far less voltage channels than the traditional one.
出处
《电力系统保护与控制》
CSCD
北大核心
2012年第2期111-115,140,共6页
Power System Protection and Control
关键词
变压器
后备保护
低电压启动
向量图
灵敏度
transformer： backup protection
low-voltage start
vector diagram
sensitivity
