孤立电网小岛运行问题的研究

Research on Isolated Power Island Running

为了对电厂经常出现的机组脱离电力网,带局部小网事故引起的汽轮机转速飞升、局部电网频率大幅波动造成的系统崩溃等严重电力事故找到有效合理的解决方案,从电网对机组调频的要求和汽轮机调节系统所具有的静特性出发,通过对此类孤网最根本的运行机组频率稳定问题解决方案的分析,提出在普通电液调节系统(Digital Electric Hydraulic ControlSystem,DEH)中加入PLU和二次调频的概念,将一次调频和二次调频相结合的方案,对如何有效地保证电网频率的稳定性和单台机孤立网运行的可靠性作出了一些有益的研究和探讨。最后,采用仿真测试和现场试验相结合的方法,对提出的方案进行了验证。诸多电厂中已将加入该解决方案的DEH控制系统投入实际应用,获得了优良的响应速率和控制精度。

To find a reasonable solution that avoids turbine speed winding and frequency crash accident resulting from power plant island running accident,based on power grid unit frequency adjustment requirement,turbine control system static characteristic,and analysis of power island running frequency stability method,a method that integrates PLU and 1st progression frequency adjustment into typical DEH control system,and combines 1st and 2nd adjustment is presented.Some helpful researches on how to effectively ensure power grid frequency and single unit power island's stability via simulating and on-site testing are given.The DEH control systems with this integrated solution have been used in several power plants,and good responding rate and control accuracy are obtained.