DEVELOPMENT AND APPLICATION OF PULSE TECHNIQUE TO POWER SYSTEM PROTECTION

A novel pulsed power generator based on IGBT stacks is proposed for wide pulsed power utilizations because it can produce high voltage pulsed output without any step-up transformer or pulse forming network, it has benefit of fast rising time, easiness of pulse width variation, high recurrence rate and rectangular pulse shapes. Proposed scheme consists of multiple power stages which were charged parallel from series resonant power inverter. Depending on the number of power stages it can boostutmost voltage up to 60 kV or higher with no limits of power stages. To minimizecomponent for gate power supply, a simple and robust gate drive circuit which delivers gate power and gate signal concurrently by way of one high voltage cable is proposed. For gating signal and power a full bridge inverter and pulse transformer produces on-off signals of IGBT gating with gate power concurrently and it has very good characteristics of protection of IGBT switches over arcing condition. It can be used for various type of pulse power utilization such as plasma source ion implantation, sterilization, water and gas treatment which needs few kHz pulse recurrence rate with few to ten of microseconds pulse width.