1050 MW机组功率-负荷不平衡保护优化研究  

Research on Optimization of Power Load Unbalance(PLU) Protection for 1050 MW

作　　者：冀树春 

机构地区：[1]神华国神集团公司技术研究院,西安710065

出　　处：《控制工程》2017年第4期810-816,共7页Control Engineering of China

摘　　要：大型火力发电机组PLU(Power Load Unbalance,PLU)保护是当外部线路故障、或者电网故障、或者其它原因导致机组实际送出的功率瞬间大幅度下降,为防止汽轮机超速,设置功率-负荷不平衡(PLU)保护,及时、快速关闭高压调节阀和中压调节阀,使汽轮机机械功率和发电机有功功率趋于平衡,维持机组3 000 rpm运行;故障消除后,又为保证电力系统功率平衡,汽轮机调节阀快速恢复调节功能,保护汽轮发电机组及电网安全运行。从PLU保护原理上分析逻辑回路存在的缺陷和其可能引起的电网及机组不安全事件,通过PLU保护取源、设备选型、逻辑优化等研究PLU保护优化方案,以提高大型火力发电机组PLU保护的可靠性,减少PLU保护误动和避免PLU保护拒动,保护汽轮机发电机及电网安全运行。The PLU （Power Load Unbalance） protection of large thermal power units is the external power system fault, or the power grid fault, or other causes of the actual power sent by the unit dropped sharply, in order to prevent the steam turbine overspeed, the power load imbalance （PLU） protection is set up, the high pressure regulating valve and the medium pressure regulating valve is closed timely and quickly, so that the mechanical power of the steam turbine and the generator active power tend to be balanced, and the operation of the unit is maintained at 3000 rpm; after the fault is eliminated, the power balance of the power system is guaranteed also, the steam turbine control valve adjustment function is recovered fast to protect the safe operation of turbine generator sets and the power grid. The defects of the logic circuit and the possible cause of the power grid and the unit unsafe events are analyzed from the PLU protection principle, and the PLU protection optimization scheme is researched through PLU protection source, equipment selection and logic optimization, in order to improve the reliability of PLU protection for large thermal power units, reduce PLU protection misoperation, avoid PLU protection rejection and protect safe operation of the steam turbine and the power grid.

关 键 词：PLU保护 逻辑回路 研究 优化 

分 类 号：TP27[自动化与计算机技术—检测技术与自动化装置]