风机双频无扰切换过程研究

Study on Undisturbed Dual-frequency Switching Process of Fans

电厂大型风机采取双频切换运行是避免风机变频故障、保障机组安全稳定运行的一种方式。以某电厂循环流化床锅炉一、二次风系统为试验对象,对风机双频无扰切换的可行性和切换过程中面临的危险点进行了理论分析,从电磁感应原理方面分析了准确的切换时间,通过现场冷热态试验对切换方案进行了论证和数据分析,提出了双频无扰切换的具体控制策略,确定了切换方案的各个参数数据,同时总结了机组相关的逻辑保护、自动调节控制策略以及快速减负荷功能的优化,为风机变频稳定运行、实现双频切换提供了参考依据。

It is a way to avoid the failure of fan frequency conversion and ensure the safe and stable operation of the unit for large fans in power plants to adopt dual-frequency switching operation.In a circulating fluidized bed boiler in one power plant,taking the first and secondary air system as the test object,the feasibility of undisturbed dual-frequency switching of fans and risks encountered in the process of switching are analyzed in theory.And the accurate switching time is analyzed from the principle of electromagnetic induction.Based on the on-site hot and cold tests,the switching scheme is demonstrated and related data analysis is carried out;the specific control strategy for undisturbed dual-frequency switching is proposed and the various parameter data of the switching scheme are determined.Meanwhile,the related logic protection,automatic regulating control strategy and RB function optimization of the unit are also summarized,so as to provide reference for the stable operation of fans when switching frequency and the realization of dual-frequency switching.