为客观评价天然气电厂的功能,在充分考虑了天然气发电机组启停迅速、运行灵活、清洁环保的基础上,该文提出了天然气电厂综合效益的概念以及综合效益的整体模型评估方法,该方法通过有等效替代原则设计原始方案与替代方案,对两方案在满足相同的静、动态任务约束下采用机组组合进行运行模拟,两方案的运行成本之差即为天然气电厂的综合效益.77机系统和某实际发电系统规划的算例结果符合实际,验证了天然气电厂综合效益的存在,并分析了产生综合效益的机理以及影响因素.

A relay configuration under special tie line situation is presented in this paper.Through the calculation of both sides relay setting,the typical relay parameters are adjusted.Finally,the existing problems of the protection configuration are pointed out and corresponding solutions and future grid plan are suggested.

Remotely monitoring the accurate temperature of transformers is an important precaution measure for ensuring the secure operation of transformers.In light of the deviation beyond regulation between real temperature and remotedly measured temperature of main transformer,by analyzing the principle of transformer temperature measurement system and researching the comprehensive factors,it is identified that the clutter interference received at temperature transmitter inputs is the major cause for the abnormal temperature deviation.Technical measure which effectively solves the deviation by using filter are introduced.

An incorrect action of anti-jumping protection of 35 kV SF6 breaker was founded on field tests after the oil-free reform of breakers.A nalysis of the breaker secondary circuit diagrams and field experiments were carried out and an abnormal phenomenon was founded in the breaker anti-jumping circuit that the anti-jumping relay was connectted after the energy storage contact.The anti-jumping protection lost its function because the anti-jumping relay could not start and self-hold in the energy storage process of breaker.A reform scheme of the breaker anti-jumping circuit was put forward and implemented.After the reform,some experiments proved the correct reaction of the anti-jumping protection and the hidden cause of accidents was eliminated.