A protection scheme for high power microwave devices

Abstract

Plasma is a mixture of free moving charged particles, to sustain these particles in ionic state, very high temperature is essential. Arcing phenomenon in these systems can cause enormous damage to the microwave tube. Fast switching circuit breakers are used to cutoff the load from the supply in cases of arcing. The crowbar is the device, which protects the load in the event of fault. The crowbar interrupts the connection between the high voltage power supply and the tube for a temporary period. This paper presents a protection scheme for Microwaves Tubes since high voltage DC power supplies are required for powering high power microwave sources such as, Gyrotron which is considered as the load for this system. These high power devices are to be protected in case of fault which should be cleared within 10μs. When a fault occurs inside Gyrotron, the maximum allowable fault energy is a critical parameter and should not exceed 10Joule. A crowbar firing card is to be designed and implemented in the system along with passive protection system. The software tool used is PSCAD.