火电机组后备软手操技术研究与实施

Research and Implementation on Soft Backup Technique for Thermal Power Generating Units

国内火电机组采用分散控制系统(distributed control system,简称DCS)实现机组实时控制。当DCS故障或由于在线检修隔绝不当引起主设备无法操作时,往往不易处理且经常扩大事故范围,给电厂带来巨大损失。若机组重要辅机运行过程中存在两套独立且不同的控制策略、信号通道共同运行、并能达到一运一备功能,无疑将极大提高重大辅机长时间运行可靠性。为此,通过田集电厂二期扩建工程后备软手操技术研究和实施工作,首次实现了机组六大风机后备软手操技术,六大风机动叶既可以通过模拟量回路控制,也能切换至后备软手操进行调控,两套控制回路处于不同控制器同时运行,提高了模拟量控制回路的可靠性。

Distributed control systems （DCS） are implemented in domestic thermal power plants to realize real-time control over the generation units. The main equipments may become inoperational due to DCS failures or improper isolation of on-line maintenance. In this case, generally it is not easy to handle the consequential problems and the accident usually will propagate, causing more severe damages to the power generating units. If there are two different independent control logics in the operation of main auxiliary equipments, of which one is the main control logic in operation and the other is the backup one on standby, the reliability of the auxiliary equipments will be no doubt greatly improved. Therefore, through the study and implementation on soft backup technique in the phase 11 expansion project of Tianji Power Plant, the backup operation on six main draught fans is realized. The movable blades of the six main draught fans can be controlled by the analog control system. It can also be switched to the soft backup control mode. These two kinds of control methods are up and running in different controllers simultaneously, thus the reliability of the analog control system is enhanced.