抽水蓄能机组空载工况分数阶PID调节控制

Fractional Order PID-based Regulation and Control of Pumped Storage Units Under No-load Condition

抽水蓄能机组运行在低水头空载工况易进入"S"特性区域,进而引起机组频率大范围波动和运行不稳定。针对传统比例—积分—微分(PID)控制在低水头空载工况下不能较好地调节抽水蓄能机组频率波动的不足,基于全特性曲线对数曲线投影变换的水泵水轮机数学模型,提出了适用于抽水蓄能机组低水头空载工况运行的分数阶PID(FOPID)调节系统模型,并运用粒子群优化算法优化FOPID控制参数,重点讨论了FOPID控制在低水头空载开机和空载频率扰动时的应用。仿真分析表明:相较于传统PID控制,FOPID控制使得低水头空载运行时机组频率和导叶开度的过渡过程有了明显的改进,提高了抽水蓄能机组调节系统的速动性与稳定性。

Under low water head and no-load conditions,the pumped storage unit is apt to fall into the“S'feature area which can lead to wide range of unit frequency fluctuations and unstable operation.As traditional proportion-integration-differentiation (PID) control under low water head and no-load conditions is unable to appropriately adj ust the frequency fluctuation problem, a fractional order PID(FOPID)regulation and control model is proposed for the pumped storage unit,where the pump turbine mathematical model is developed based on the complete characteristic curves by using logarithmic proj ection transformation, and the regulation parameters of FOPID are optimized by particle swarm optimization (PSO) algorithm.This paper is mainly concerned with the application of FOPID control for two simulated experiments,including unloaded start-up operation and unloaded frequency perturbation condition under low water.Simulation analysis demonstrates that FOPID control is capable of significantly improving the transition process of the frequency of pumped storage unit and guide vane opening.Meanwhile,the FOPID control will enhance the dynamic performance and stability of the pumped storage unit governing systems.