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.