Design and Application of a Thyristor-Based Half-Sine Pulsed Power Converter for Eddy Current Septum Magnet

The Shanghai Synchrotron Radiation Facility (SSRF) utilizes six in-vacuum eddy current septum magnets operating at a 2 Hz pulse rate in its injection and extraction system. These magnets include one for booster injection, three for booster extraction, and two for storage ring injection. The inductance of the septum magnet is approximately 2.1 µH. Each septum magnet is driven by one pulsed power converter. The required exciting current is a peak current of approximately 4–10 kA and a half-sine-wave with a base width of approximately 60 µs. Over 10 years of operation, the failure rate of septum magnet pulsed power converters in the SSRF has increased in the last 2 years. To address this issue, an upgrade of half-sine pulsed power converters for septum magnets has been implemented to enhance system reliability. The study outlines the pulsed septum magnets, the upgrade process for pulsed power converters, and the electronic components required, such as energy-storage capacitors, energy recovery circuits, protection circuits, and thyristors. Additionally, the study presents experimental results related to the upgraded pulsed power converter.