EHV电网中应用的非传统互感器

Use of Non Conventional Instrument Transformers for EHV Applications

对高于800kV的特高压，不应使用油纸绝缘作为电流互感器的绝缘方式。原因是电流互感器的绝缘会产生很多热量，对互感器的热稳定性造成威胁。对高达1100kV电流互感器可用现有800kV的SF6间隙绝缘技术，但是按照SF6绝缘距离的要求，建造重8t，耗资大的TA有潜在的危险。非传统的互感器（NCIT）已在特高压电网中有所应用，其优势是：安全性、低成本、紧凑性、节约空间、接线容易、自我监控、减少库存、改善测量、采样值的数字通信、谐波测量能力和电力质量。

The use of paper and oil for extra high voltage insulation （EHV） of current transformers at voltages higher than 800 kV is not recommended. The main reason is the increasing quantity of heat generated in the paper, being dangerous for stability. It is probably possible to extrapolate existing 800 kV technologies of SF6 insulated free standing current transformers up to 1100 kV but the rules of insulation free distances in SF6 gas lead us to build a monster of 8 tons, very expansive and potentially dangerous. Non Conventional Instruments Transformers （NCIT） are may be the proposed right solution. They are nowadays in industrial stage and advantages are expected, particularly in an EHV network, such as： safety, cost reduction, compactness, space savings, wiring easiness, self-monitoring, reduced inventories, measurement improvements, digital communication for sample values, harmonics measurements capability and Power Quality.