自动电压控制中强耦合电厂的协调控制方法

Method of Coordination Among Strongly Coupled Power Plants for Automatic Voltage Control

为解决强耦合电厂间无功出力不均衡的问题,提出了强耦合电厂间的无功电压协调控制(厂厂协调)方法。该方法建立包含相互强耦合的厂厂协调组,并作为协调单元;定义厂厂协调组无功负载率偏差指标,若中枢母线电压未调节到位,进行考虑厂厂协调约束的协调二级电压控制,使得在中枢母线电压追踪优化设定值的同时,保证强耦合电厂间的无功负载率偏差满足控制要求;若中枢母线电压已调节到位,进行基于厂厂协调目标的无功校正控制,降低强耦合电厂间的无功负载率偏差,并保证中枢母线电压维持在控制死区范围内;在传统电压调节指令的基础上增加无功调节指令,抑制强耦合电厂间可能出现的不合理无功分布或无功波动。文中成果已在国内多个网、省级电网得到实际应用,仿真及实际运行效果表明该方法可有效减少强耦合电厂间的不合理无功分布。

To solve the problem of reactive power non-coordination among strongly coupled plants,a coordinating method for strongly coupled plants for automatic voltage control(AVC)is proposed.The coupling coefficient among plants is introduced,and the plant coordinating group is generated as the coordinating unit.The reactive power unbalanced index among strongly coupled plants is defined.And the current operation state of power grid is determined.In the event the pilot bus voltage is not controlled in place,the control strategy of voltage regulation and reactive power tracking control is adopted so that the pilot bus voltage will be enabled to guarantee that the reactive power unbalanced index between strongly coupled plants will meet the control requirement while tracking optimal settings.If the pilot bus voltage is already in place,reactive correction control based on the objective of plant-to-plant coordination will be carried out to reduce the deviation in reactive load while ensuring that the pilot bus voltage is maintained within the range of control dead zone.Reactive regulating commands will be added to the traditional voltage regulating commands to suppress possible irrational reactive power distribution or reactive fluctuation between strongly coupled plants.Application of the proposed method in a number of regional and provincial grids in China shows that the proposed method is able to reduce irrational reactive power distribution between strongly coupled plants.