大中型发电机主保护方案和配置的定量化设计——发电机内部短路仿真软件的应用

QUANTITATIVE DESIGN OF MAIN PROTECTION CONFIGURATION SCHEMEFOR LARGE AND MEDIUM GENERATORS--Application of the Internal Faults Simulation Software

通过2台单机700MW的发电机(三峡电厂)和2台135MW的发电机(平班电厂和百色电厂)主保护方案的设计,对现行设计工作中完全凭概念、经验和传统习惯的做法的科学性提出了质疑,究其原因在于没有掌握发电机内部短路的正确分析计算,不得已用机端金属性两相短路来校验保护方案的灵敏度,使得设计者对于所设计的主保护配置方案的性能心中无数。主保护配置方案的定量化设计将主保护方案的性能与发电机实际可能发生的内部短路紧密联系起来,在此基础上,按照“优势互补、综合利用”的原则寻求最佳的主保护配置方案,为大中型发电机的安全运行提供了高质量的保证。平班电厂和百色电厂发电机主保护设计的实例进一步说明在全面的内部短路分析计算的基础上进行主保护配置方案定量化设计的重要性。

Through the designs of main protection scheme for two Three Gorges generators (rated power 700 MW) and two 135 MW generators (Pingban and Baise generators), it is pointed out that the traditional design method of main protection scheme for generator is short of scientific basis. The traditional configuration of main protection scheme depends on the conception of protection, the experience of designers and the habitual configuration of other power stations. For instance, lack of accurate calculation of the short circuit current of stator winding forces the designer to check the sensitivity of main protection schemes by use of the short circuit current at generator terminal and thus the performance of the designed schemes is misunderstood. By the quantitative design of main protection configuration scheme, the performance of main protection scheme and the possible internal faults of generator should be closely contacted. The final main protection configuration scheme is optimized according to the design principle namely advantage complementation and comprehensive utilization. The high quality design achievement can be acquired by using the quantitative design method and it is beneficial to the safe operation of the large and the medium generators. From the design examples of Pingban and Baise generators, it' s realized that the quantitative design method based on the simulation of all possible slot and end faults of generator is very important.