A High Performance Digital Triggering System for Phase Controlled Rectifiers

The larger power supplies used to power accelerator magnets are most commonly polyphase rectifiers using phase control. While this method is capable of handling impressive amounts of power, it suffers from one serious disadvantage, namely that of sub-harmonic ripple. Since the stability of the stored beam depends to a considerable extent on the regulation of the current in the bending magnets, sub-harmonic ripple, especially that of low frequency, can have a detrimental effect. At the NSLS, we have constructed a 12 pulse, phase control system using digital signal processing techniques that essentially eliminates sub-harmonic ripple.