基于FPGA的高频低电平系统的研制与调试

Development and Test of High Frequency Low Level System Based on FPGA

为了使腔体在过束过程中,获得稳定的能量增益,研制了高频低电平系统,采用全数字技术,完成了对腔体工作频率、幅度与相位的精确反馈控制。通过现场测试与理论分析建立高频腔的物理模型,设计相应的PI控制器,并进行仿真验证,提升系统的稳定性,优化了调谐的精度与速度。高频低电平系统克服了高频回路中外部噪声、腔体机械形变、热形变对闭环回路、幅度、相位造成的影响。系统在室温环境下进行测试,在2h内控制腔体相位稳定度为±0.6°,幅度稳定为±0.8%,达到了设计要求。

For the purposes to obtain a stable energy gain in the process of passing the beam through the cavity,the high frequency low level radio frequency(LLRF)control system was developed,which used full digital technology to complete the precise feedback control of the working frequency,amplitude and phase of the cavity.The corresponding PI controller was designed by establishing physical model of the high frequency cavity,and the simulation verification was carried out,so that the stability of the system was improved,and the tuning accuracy and speed were optimized.The cavity overcomes the influences of external noise and cavity deformation during tuning by the LLRF control system.The system reaches the requirements of design which can keep phase stability of±0.6°and the amplitude stability of±0.8%within 2 hours test at room temperature.