LIU Haizhe, TIAN Liang. Design of feed-forward control logic of coordinated control system of thermal power units[J]. Thermal power generation, 2018, 47(10): 78-83.
DOI:
LIU Haizhe, TIAN Liang. Design of feed-forward control logic of coordinated control system of thermal power units[J]. Thermal power generation, 2018, 47(10): 78-83. DOI: 10.19666/j.rlfd.201712171.
Design of feed-forward control logic of coordinated control system of thermal power units
摘要
为满足电网调峰调频需要
火电机组自动发电控制(AGC)指令频繁大幅变化
导致机组燃料量波动加剧
严重影响机组运行安全性及经济环保性。依据简化的非线性动态模型
对炉跟机方式协调控制系统发电负荷指令对燃料量的前馈控制逻辑进行推导
发现其基本结构为超前补偿环节
超前补偿环节的大微分作用造成变负荷工况下燃料量的波动。因此
重新构造了非线性微分环节超前补偿逻辑
在施加相同微分控制量时
降低微分输出的瞬时变化幅度并缩短调节时间
从而降低由前馈微分作用带来的燃料量波动。将重新构造的非线性前馈控制逻辑应用于亚临界330 MW机组
调试结果表明优化后的控制方案能够在实现相同控制指标的前提下
显著降低变负荷工况下燃料量波动幅度。
Abstract
In order to meet the needs of peak regulation and frequency regulation in power grid
the instruction of automatic generation control of thermal power units changes frequently
leading to an increase in fluctuation of fuel consumption of the units
which seriously affects the operation safety
economy and environmental protection of the units. According to the simplified nonlinear dynamic model
the feed-forward control logic of power load instruction to fuel consumption in the coordinated control system in the boiler-following-turbine mode was deduced. It is found that the basic structure of the model is the lead compensation link
and its large differential action causes the fluctuation of fuel consumption under variable load conditions. Therefore
the lead compensation logic of the nonlinear differential link was reconstructed. With the same differential control quantity
the instantaneous variation range of differential outputs was reduced and the adjustment time was shortened
thus to reduce the fluctuation in fuel consumption caused by the feed-forward differential action. The reconstructed nonlinear feed-forward control logic was applied to a 330 MW subcritical unit
the commissioning results show that the optimized control scheme can significantly reduce the fluctuation range of fuel consumption under variable load conditions on the premise of achieving the same control index.