| Abstract |
In the field of particle accelerators a resonant circuit, a so called "White circuit", is used to provide a highly stabilized (10to-4) low distored (10to-4) accurately timed waveform for the bending and focussing magnets. This current is composed of a DC- and AC-part with equal amplitude. PWM technics have been applied to develop a new GTO-inverter concept for the AC-part. A study of the existing solutions for one of the European institutes (ESRF) led to the application of PWM technics for this AC-part. A strong reduction of mains flicker is achieved. A new generation of GTO-inverters has been developed to meet the severe specifications. A range of inverters from 5 to 350 kW is built. The current source inverter contains diode-bridge, filter, GTO-chopper with DC-choke and GTO-inverter. This paper describes the White circuit, AC-inverter diagram, applied PWM technics and typical current and voltage waveforms. Also mains interaction, control philosophy and precise timing is discussed. |
