继电保护模拟实验装置是继电保护教学实践的重要设备。微机继电保护技术的发展与应用给继电保护的教学实验注入了行的内容。传统继电器型的继电保护和微机继电保护装置在工程应用中共存，为了适应能体现不同形式的继电保护，适应教学实验，论文以典型的电力线路三段式过流保护为主要内容，设计了电力线路保护模拟实验装置。有意义的主要成果体现在： 提出了电力线路继电保护模拟实验装置总体框架，框架包括基于继电器的三段式过流保护、基于可编程控制器PLC的三段式过流保护和基于单片机STC89C52三段式过流保护等模拟实验功能；具有体现继电保护不同硬件形态的全面性特点。 给出了电力线路三段式过流保护装置的软硬件设计，完整的体现了继电保护不同实现手段。其中基于继电器的三段式过流保护单元可用于继电保护保护的原理验证，体现传统继电保护的特点；基于PLC的三段式过流保护可用于验证计算机保护动作逻辑修改的方便性，同时兼具直观性；基于单片机的保护功能出具有三段式保护功能外，还具有零序电流方向保护的实验功能，可用于验证微机式继电保护所具有的可靠性、使用和功能扩展的方便性。 论文还给出了电力线路三段式保护模拟实验装置的教学实验应用范例，并进行了实验验证，结果表明该模拟实验装置运行可靠，能较好的同时体现传统继电器型保护的直观性、又能体现现代微机式继电保护的先进性，装置设计合理、便于教学使用，具有较高的实用价值。

Relay protection simulation experiment is an important equipment of relay protection teaching practice. Development and application of microcomputer relay protection technology to relay protection teaching experiment into the lines. Traditional relay type of relay protection and microcomputer relay protection device in engineering, can reflect different forms of relay protection, in order to adapt to the teaching, the main content is a typical electric power line a three-stage over-current protection, power line protection simulation experiment device is designed. The main result of meaningful embodied in: Power line relay protection simulation experiment equipment is put forward the overall framework, the framework includes a three-stage over-current protection based on relay, based on programmable controller PLC, a three-stage over-current protection and based on the microcontroller STC89C52 simulation functions such as a three-stage over-current protection. Power line is given a three-stage over-current protection device of hardware and software design, complete embodies the relay protection of different methods of implementation. Based on three-stage over-current protection relay unit can be used to relay protection to protect the verification, embody the characteristics of traditional relay protection; A three-stage over-current protection based on PLC can be used to verify the computer protection. Based on single chip microcomputer protection outside has a higher protection functions and also experiment with zero sequence current direction protection functions, can be used to verify reliability of relay protection of microcomputer type, ease of use and function expansion. Paper also gives a power line protection simulation experiment device of three stages of teaching experiment, and experimental verification, the results show that the simulation test device reliable operation, can better reflect intuitive nature of the protection of traditional relay type at the same time, and can reflect the advanced nature of modern relay protection of microcomputer type and teaching unit design is reasonable, easy to use and has high practical value.