[关键词]
[摘要]
为解决火电机组灵活调峰时高压加热器水位偏差过大的问题,以600 MW火电机组为研究对象,提出一种基于最小二乘法的高压加热器水位改进前馈控制策略,通过前馈补偿作用快速响应扰动条件的变化,减小灵活调峰运行过程中高压加热器水位的偏差。该方法通过负荷分段得到一组不同负荷工况下的数据,并利用最小二乘方法进行改进的静态前馈控制系数的拟合,进而获得改进的高压加热器水位前馈控制系统的多变量回归模型。进行负荷点间隔和取值范围变化的仿真试验,并开展现场实验进行验证。结果表明:负荷点间隔越大,原始数据的信息丢失越多,补偿效果越差;负荷点取值范围越大,数据难以集中反映对应负荷下的工况。现场实验结果表明,前馈投入后水位误差均方根、误差极大值和误差平均值均降低了约50%。
[Key word]
[Abstract]
To solve the issue of large deviation of water level of highpressure heaters of coalfired power plants under the state of flexible peak regulation,this paper presents an investigation for a 600 MW coalfired power unit.A modified feedforward control strategy for water level of highpressure heater is put forward based on the least minimum square method.Through the rapid response of feedforward compensation for disturbances,the water level deviation of highpressure heater may be reduced under the condition of flexible peak regulation.This control strategy obtains the data of different load conditions based on load dividing,and the modified static feedforward control coefficient is calculated by the least minimum square method.Then the multivariable regression model of modified feedforward control strategy for water level of highpressure heater is obtained.Simulations for different load dividing intervals and ranges are conducted,and field experimentations are done for validation.Results show that the compensation effect is worse with the increase of load dividing interval,because more initial data is lost.When the load dividing range increases,the data for control coefficient fitting cannot represent the actual load conditions.Field experimentation results show the error root mean square,error maximum and average error of water level are reduced by 50% after the modified feedforward control strategy is employed.
[中图分类号]
TM621
[基金项目]