火电厂单机带孤网运行控制策略

Control strategy of single power unit with isolated operation in thermal power plant

为解决受冰灾影响的桂林区域电网的安全供电问题,根据国电永福电厂2号机组单机带孤立电网运行的工程实践,提出火电机组单机孤网运行时采用DEH一次调频的频差修正回路进行频率控制的方案,以及机组孤网运行时控制系统的技术改进措施和电气、锅炉、汽轮机等专业的运行控制策略。通过对机组孤网运行的过程曲线跟踪分析,对一次调频死区进行调整,解决了汽轮机顺序阀运行方式时调门重叠度引起的汽轮机转速振荡问题。该机组单机带孤网运行的成功,使受到冰灾影响与广西电网主网断开的桂林网区有了安全保障,避免了桂林市全城停电。

To solve the safety problems in local power supply of Guilin power grid affected by the ice disaster, a frequency control solution was proposed based on the engineering practice of single power unit with isolated operation in Guodian Yongfu Thermal Power Plant. The frequency difference correction loop of DEH primary frequency regulation was used for frequency control in case of single coal-fired power unit with isolated operation. In addition, the technical improvements of control system and control strategies were presented, covering the operation of boiler, turbine and electrical system. According to the tracking analysis of operation curves for the single unit on isolated operation, by regulating the dead zone, the speed fluctuation problem of steam turbine was solved, which was caused by the overlap degree of control valve in sequence valve mode. The successful experience provided security assurance for Guilin power grid, disconnected from Guangxi grid by ice disaster, so as to avoid the blackout in Guilin.