IGBT gate driver upgrades to the HVCM at the SNS

The SNS at ORNL has been fully operational since 2006 and in September 2009, the design goal of 1 MW of sustained beam power on target was achieved. Historically, the high voltage converter modulators (HVCM) have been a known problem area and, in order to reach another SNS milestone of ≥90% availability, a new gate driver was one of several areas targeted to improve the overall reliability of the HVCM systems. The drive capability and fault protection of the large IGBT modules in the HVCM were specifically addressed to improve IGBT switching characteristics and provide enhanced troubleshooting and monitoring capabilities for the critical IGBT/driver pair. This paper outlines the work involved; the result obtained and documents the driver´s long-term performance. Enhanced features, designed to be used in conjunction with a new controller presently under development, will also be discussed.