城市水厂变频调速泵群优化控制策略

Optimal Control Strategy of Variable-Frequency Variable-Speed Pumps in Urban Water Supply Plants

提出了城市水厂完全变频调速泵群优化控制问题的最小轴功率模型,利用枚举法和约束变尺度优化算法求解模型,得到最佳控制策略.对比单变速泵群优化模型,进行了仿真实验.结果表明,目前广泛应用的单变速泵群方案无论在经济上和还是在技术上都不合理;完全变频调速泵群依靠优化控制策略和强大的调节能力,使各台水泵在效率峰值点附近运行,且不易出现无解的现象,其平均节电率比单变速泵群高6%～7%,节电效益显著,投资回报率高,且软启动性能好.

For the aim of saving energy and optimizing control of water supply system, an optimal modeling method of urban water supply pumps is proposed, in which the main objective is to minimize the shaft horsepower of pumps entirely fed by inverters. The formulated optimization problem is solved by applying enumeration and reduced gradient algorithm and the optimal solution of control variables is obtained. To compare with the scheme of single variable-speed pumps, a lot of simulations are made. The simulation results show that, the widely accepted scheme of single variable-speed pumps is improper not only in economy but also in technology, while the proposed scheme can overcome these shortcomings by using optimal control strategy and powerful modulation capability of the system. All of the pumps in the proposed scheme can be operated around their highest efficiency points, and the average electric saving rate is higher than that of a single speed-variable pump system by 6%-7%. It has good soft start performance.