【目的】循环水泵采用屏蔽式三相交流异步变极电机，该变极电机高速和低速工况切换过程需要断电较长时间，导致电机转速及工艺回路流量出现大幅度跌落。为实现上述工况平稳切换，本文提出了一种高速、低速工况相互切换的控制策略。【方法】首先以该循环水泵的变极电机为分析对象，利用电机变极原理及交流异步电机数学方程，建立了变极电机的仿真模型，搭建了变极电机低速、高速驱动控制仿真模型。为尽量减少切换过程回路流量跌落以减少电机转速跌落为目的，分别研究了变极电机高速、低速相互切换过程中电机剩余感应电动势、电机转速等参数的动态变化特征。结合变极电机工况切换过程需要考虑的限制性条件，针对性设计了变极电机低速切高速和高速切低速控制策略。将该控制策略应用于循环水泵配套的变频电源研制中，通过台架试验验证了变频电源与循环水泵之间的匹配性。【结果】试验结果表明，该控制策略较好地实现了循环水泵高速与低速工况之间的平稳切换，满足循环水泵对运行工况切换的要求。高速切换至低速过程中将转速跌落、回路流量跌落控制在22.7%，低速切换至高速过程中将转速跌落、回路流量跌落控制在25.4%和25.5%。【结论】本文提出的循环水泵变极电机高速、低速工况之间的相互切换策略，较好地解决了循环水泵的工况切换难题，具有较高的工程应用价值。

Abstract: ［Objective］ The circulation water pump adopts a shielded three-phase AC asynchronous pole-changing motor. During the high-speed to low-speed mode transition and the low-speed to high-speed mode transition, this motor requires an extended power interruption period, resulting in significant drops in both motor speed and process loop flow rate. To address this mode transition challenge, a novel bidirectional control strategy for seamless switching between high-speed and low-speed operation modes is proposed at the paper. ［Methods］ First, taking the pole-changing motor of the circulation water pump as the analysis object, a simulation model of the pole-changing motor was established based on the pole-changing principle and the mathematical equations of AC asynchronous motors. A simulation model for low-speed and high-speed drive control of the pole-changing motor was then constructed. To minimize the flow rate drop during the switching process, with the goal of reducing motor speed drop, the dynamic characteristics of parameters such as the motor's residual electromotive force and speed during mutual switching between high-speed and low-speed modes were investigated. Concurrently, considering the operational constraints during pole-changing motor mode transition, a control strategy for switching from low-speed to high-speed and from high-speed to low-speed was designed. The proposed control strategy was applied to the development of the frequency converter power supply for the circulation water pump. Bench tests demonstrated excellent compatibility between the power supply and the circulation water pump. ［Results］ The experimental results confirmed that smooth switching between high-speed and low-speed operation modes were achieved, and operation mode switching requirements for circulation water pump. During the transition from high-speed to low-speed mode, the speed fluctuation was controlled within 22.7% and the flow fluctuation was maintained within 22.7%. Conversely, during the transition from low-speed to high-speed mode, the speed fluctuation was limited to 25.4% and the flow fluctuation was kept within 25.5%. ［Conclusion］ The pole-changing strategy proposed in this paper for switching between high-speed and low-speed operation modes of circulating water pump motors effectively resolves the challenges of operational mode transition, demonstrating significant engineering applicability.

国家自然科学基金（U2267206）