梯级电站联合运行水位无差状态反馈调节器

State feedback controller without steady-state error for water level in regulating reservoir of cascade hydropower plants

为了实现梯级串联电站系统的稳定运行,基于最优控制原理,将站间调节池的水位偏差值引入上一级电站的反馈调节器中,提出了在进行功率(或转速)调节的同时能够平衡电站间流量,并使站间调节池的水位得到调节与控制的状态反馈调节器.通过数值仿真试验,比较了转速、调节池水位和导叶开度的不同权重因子对系统动态特性的影响.由仿真结果可以看出,转速和调节池水位的权重因子对调节品质影响小,改变转速和调节池水位的权重因子,转速的最大变化相对值均为3%左右,调节时间大约为45 s;调节池水位的最大变化相对值均为0.011%,调节时间约为4 000 s.而当导叶开度权重因子从130减小为1时,其转速的最大变化相对值减小约46%;调节池水位最大变化相对值减小41%,调节时间减少为原来的33%左右,所以采用较小的导叶开度权重因子设计出的最优控制调节器,机组转速的调节时间缩短,峰值降低,调节池水位的峰值也降低.为了便于实际应用,选择合理的权矩阵设计了能实现梯级电站联合运行时站间水位无差调节的状态降维反馈调节器.由仿真结果可以看出,状态降维前后,转速、调节池水位等状态量的调节品质相差不大.

In order to keep the stability of operation of cascade hydropower stations,a state feedback controller is designed based on optimal control theory. The water level deviation value of the regulating reservoir between two power stations is introduced to the feedback regulator of the upper station. As a result,it can regulate the speed,and balance the discharge of each station to stabilize the water level.Effects of weighting factors of speed,water level and guide vane opening on system dynamic characteristics of the controller are compared by numerical simulations. The results show that the weighting fac-tors of speed and water level have a little influence on the regulation quality. For example,the maximum change in speed is about 3% in 45 s settling time; the maximum change in water level is approximately 0. 011% in 4 000 s settling time. However,when the weighting factor of guide vane opening is reduced to 1 from 130,the maximum change in speed is decreased by approximately 46%,the maximum variation of water level is lowered by about 41%,and the settling time is shortened to approximately 33%. A controller with a smaller weighting factor in guide vane opening can reduce the settling time of speed and fluctuations in speed and water level. In order to facilitate practical application of the controller,by reasonably selecting a weight factors matrix,a reduced-order state feedback controller is designed to realize zero error in water level in regulating reservoir. According to the simulation results,regulation quality of the states,such as speed and water level reservoir has little difference between the reduced-order state feedback controller and the full-state feedback controller.