The study on PSC/PSI application of BEPCII power supply prototype

There are about 350 magnet power supplies such as B, Q, S and so on in BEPC II double rings. Since power supplies need to be redesigned because of the number increasing from 97 to 350, the control system for the power supplies need to be rebuilt. According to the requirement of the magnet power supplies with 5 x 10-5 precision and stability, the authors decided to use a BNL-designed PSC/PSI (Power Supply Controller/Interface) to control these high precision power supplies to ensure their stability and against EMI. So, authors changed the interface of the PSI so that the PSI is suitable for the prototype power supply. The prototype power supply is made with the interface circuit to the PSI. This paper describes the PSC/PSI application to the prototype power supply and some problems about the grounding between the control interface and devices. The authors present some methods how to solve the interference from the bad grounding of the system and power supply EMI. (authors)