Design of a Self-Optimizing Magnet Power Supply Controller for the Hefei advanced light facility

Abstract [Background]: The Hefei Advanced Light Facility (HALF) is a fourth-generation synchrotron radiation source based on a diffraction-limited storage ring. Its electron beam energy is 2.2 GeV, with an emittance target of less than 100 pm·rad. Due to the need for over a thousand magnet steady-state power supplies at HALF, the empirical tuning method using conventional PID controller parameters requires a significant amount of time. [Purpose]: This study aims to design a PID controller parameter auto-tuning algorithm for the magnet steady-state power supply of HALF, to achieve optimal PI parameters. This ensures stability within 50 ppm for the magnet steady-state power supply and reduces overshoot in step response when changing the current operating point, facilitating smooth transitions. [Methods]: Based on polynomial regression and genetic algorithms, an auto-tuning algorithm for PI controller parameters was developed for the magnet steady-state power supply controller. This algorithm was integrated with the supervisory computer system to record various data points. Development and testing of this algorithm have been completed on the magnet steady-state power supply. [Results]: The tests on the power supply step response and output current stability show that the step response can achieve a smooth transition, and the rising speed is increased several times. The output current stability is within 10 ppm. The key technical indicators meet the operation requirements and significantly improve the debugging efficiency. [Conclusions]: The algorithm proposed in this paper provides an effective method for improving the debugging efficiency of large-scale power supplies in the future.

摘要
[背景]：合肥先进光源（Hefei Advanced Light Facility, HALF）是基于衍射极限储存环（diffraction-limited storage ring）的第四代同步辐射光源，其电子束能量为2.2 GeV，发射度指标要求低于100 pm·rad。由于HALF需配置千余台磁铁稳态电源，采用传统PID控制器（PID controller）参数的经验调谐方法需耗费大量时间。
[目的]：本研究旨在为HALF的磁铁稳态电源设计一套PID控制器参数自整定算法，以得到最优PI（Proportional-Integral）参数，确保磁铁稳态电源的稳定性控制在50 ppm以内，同时降低切换当前工作点时阶跃响应的超调量，实现平滑过渡。
[方法]：本研究基于多项式回归（polynomial regression）与遗传算法（genetic algorithm），开发了针对磁铁稳态电源控制器的PI控制器参数自整定算法，并将其与监控计算机系统集成以记录各类数据点。该算法已在磁铁稳态电源上完成开发与测试。
[结果]：对电源阶跃响应与输出电流稳定性的测试表明，阶跃响应可实现平滑过渡，上升速度提升数倍；输出电流稳定性优于10 ppm。关键技术指标满足运行要求，且显著提升了调试效率。
[结论]：本文提出的算法为未来大型电源系统的调试效率提升提供了有效途径。