摘要:厂用电保护的配置及整定计算直接关系到厂用设备的正常可靠运行,继而影响到电厂的安全和稳定。随着电力工业的迅速发展,我国发电机、变压器单机容量不断增大,电力系统正朝着“大机组、超高压、大电网”的方向发展。如今我国大容量电厂不断变多,它们在电力系统中地位更加显得重要。为了保证整个电力系统的安全运行,我们应对电厂配置可靠性、灵敏性、选择性和速动性都很好的保护装置。
我的本次毕业设计的主要内容是针对110KV电力系统继电保护的配置,然后根据继电保护配置原理,对所选择的保护进行整定计算和灵敏度校验,确定所选保护。计算标幺值,短路电流,确定运行的方式。然后确定各种设备的保护配置,有变压器、母线、输电线、发电机。对于变压器,主保护采用纵联差动保护与瓦斯保护,优势互补。对于母线来说,采用完全电流差动保护,简单可靠。后备保护采用复合电压启动过电流保护。
关键词 继电保护;标幺值;整定计算;电流保护
Abstract:The configuration and setting calculation of electricity protection in the power plant have direct links to the regular and stable running of the equipments in the plant, which in turn affects the safety and stability of the power plant. With the rapid development of power industry, the power system is heading for the development of “larger unit, higher pressure and bigger grid” since the unit capacity of generators and transformers has been ever increasing. Nowadays with the increasing number of high-capacity power plants, the configuration and calculation play a more significant role in the power system. In order to ensure the safe running of the whole power system, we should carefully protect the configuration of the power plant in terms of its reliability, flexibility, selectivity and velocity.
My graduation project mainly focuses on the configuration of relaying protection of 110KV power system. Based on the principle of relaying protection configuration, I calculate the selected protection and examine its sensitivity so as to determine the chosen one. I also calculate the per-unit value and short circuit current so as to determine the running mode. Then I am able to decide the protection configuration of all equipments, such as transformers, bus bars, transmission lines and power generators. As for transformers, the main method is the combination of longitudinal differential protection and gas protection, which are complementary to each other. When it comes to bus bars, the simple and easy way is to use fully current differential protection and over-current protection of composite voltage start is adopted for back-up protection.
Keywords relaying protection per-unit value setting calculation current protection