核电厂保护系统对维护核电厂正常运行有着重要作用。本研究提出了基于SIMATIC S7-300 PLC（可编程自动控制器）的核电厂保护系统方案，详细介绍了保护系统的工作原理、结构、设计及该系统的应急设计和运行期间的故障检测。对于该系统的关键技术进行具体分析，其中针对核反应堆的检测温度存在非线性，采用模糊PID控制算法处理系统内的温度信号，实现了稳态调节,最后运用仿真软件对系统进行模拟测试。仿真结果表明：该核电厂保护系统在处理信号时具有循环周期短、处理速度高和指令集功能强大的特点，可以为核电厂24 h稳定安全运行提供保障。

The protection system of nuclear power plant plays an important role in maintaining the normal operation of nuclear power plant.In this paper,a scheme of nuclear power plant protection system based on SIMATIC S7-300 PLC is presented.The working principle,protection system,and structure design are introduced.And also described are the design for the emergency and the fault detection during the system operation.The key technology of the presented system is analyzed in details,in which the nonlinear temperature exists in the nuclear reactor,and the fuzzy PID control algorithm is used to deal with the temperature signal in the system.Finally,the simulation software is used to simulate the system.The simulation results show that the protection system of the nuclear power plant has the characteristics of short cycle period,high processing speed and powerful instruction set,which can guarantee the safety and safe operation of the nuclear power plant for 24 hours a day.

TK223.23

中国科学院等离子体物理研究所基金（DSJJ-15-GC02)；国家自然科学基金（11605234）