Research And Implementation Of Real-time Control Method For Heavy-ion Accelerator Digital Power Supply

Based on the research of features and control objective of the power supply system for heavy-ion accelerator, the characteristics, implementation goal and design thinking of a real-time control system for power supplies in the heavy-ion accelerator field were discussed. With the help of the research and development of digital power supplies for a heavy-ion cancer therapy device, the design and development method of the hardware and software of an FPGA-based controller for power supplies was researched, including some problems and the solutions in the process of the development. There are two typical examples: one is the problem of instability of Ethernet communications; the other is the problem of unreliability of the controller during long-time operation. Additionally, some key problems of hardware and software under construction of a real-time control system for digital power supplies were discussed. With the objective of optimizing the performance of the heavy-ion accelerator system and combined with the characteristics of high reliability, multi-function and high integration of digital power supplies, some design methods for digital controller for heavy-ion accelerator power supplies were discussed, such as collaborative design between software and hardware, integration control method and so on.After the research of the control system of digital power supplies for heavy-ion accelerator, some real-time control algorithms for special power supplies for the device were devised and implemented according to the requirements of the accelerator system. Firstly, synchronous control of digital power supplies for heavy-ion accelerator was discussed, and a new synchronous timing trigger system for digital power supplies in heavy-ion accelerator was developed based on the SOPC as well as the VHDL. On the basis of the trigger system, some trigger test experiments and real-time control of digital power supplies were performed. Secondly, deep researches of two typical real-time control processes were first carried out on the digital power supplies based on an FPGA controller: one is a real-time control of orbit correction power supplies for the heavy-ion synchrotron; the other is an active spot scanning control of digital power supplies in the formation system of the cancer therapy irradiation field. According to the working principle of corresponding system and the requirements for digital power supplies, two control algorithms for the two type power supplies were designed, and then the control algorithms were implemented on the power-supply digital controller by using VHDL and NIOSII C program. Especially, active spot scanning control employed two implementation methods, real-time response method and integration control method. Finally, all the algorithms implemented on digital power supplies were tested, the test data were obtained, and the feasibilities of the control algorithms were verified.This work would provide the heavy-ion cancer therapy project some vital technology in order to achieve the project goals; furthermore, this work would show engineers some valuable references for further research of digital power supply real-time control.