摘  要：市政网管叠压供水系统中普遍存在水泵机组运行效率较低的问题，传统的做法是采用恒压频比控制来提高电机运行效率，系统仍存在很大的节能空间。该文根据水泵的数学模型，分析了水泵的负载特性，结果表明转速降低时其负载特性低于理论的二次方转矩负载；在考虑铁耗的异步电机等效模型基础上，研究了异步电机最小损耗的控制策略，获得了最优运行磁通的控制方法，通过采用改进的矢量控制策略补偿了铁耗引起的磁场定向误差。仿真研究表明，与恒压频比控制方式相比，最小损耗控制策略可以在保持电机静态特性的同时，显著降低电机磁通、减小电机损耗，进而提高供水系统运行效率。
关键词：叠压供水；异步电机；铁耗；矢量控制；效率优化

Abstract: The low efficiency of pump unit are quite common in network pressure-superposed water supply system,the strategy of constant voltage and frequency ratio is usually used to improve the motor efficiency,but there is still energy saving potential.According to the math model and load characteristic of pump,it shows that,when the speed turns down,the real torque characteristic is below the quadratic one.Based on an asynchronous motor model with considering the core loss,this paper studied on the strategy of loss minimization control of asynchronous motor and achieves an optimal flux control.The error in field orientation caused by coreloss was compensated by an improved vector control.Compared with the strategy of constant voltage and frequency ratio,the stimulation showsloss minimization control in water supply system keeps the static characteristic,decreases the flux value and the loss,then it improves the operational efficiency.
Key Words: Network pressure-superposed water supply system;Asynchronous motor;Core loss;Field oriented control;Efficiency optimization