User Manual
AMETEK Programmable Power
BPS Series
115
6.7.1
PFC Input Power Converter
The PCF section is located at the bottom of each power module. AC power enters the power module at the
PFC input section. The PFC section using a PWM boost converter to turn the unregulated three phase 140
VAC into a regulated ± 225 V DC bus. A bank of capacitors is used to provide ride-through and to
support high peak current demands from the amplifier boards. The PFC PWM circuit drives a set of three
high capacity IGBT's. These IGBT's connect directly to the DC bus bars, which connect the PFC output
to the Amplifier boards.
The condition of the PFC section is constantly monitored and reported to the system interface board. If the
DC bus goes out of acceptable operating range, a fault is generated. Furthermore, in any of the three AC
input phases fails, the BPS will shut itself down.
6.7.2
Modulator Board
The modulator board is located directly above the PFC board and next to the four-board Amplifier stack.
The modulator board accepts an oscillator output reference signal as input and drives the four amplifier
boards using a high frequency PWM technique. The modulator has the ability to drive the amplifiers in
either parallel or series configuration, thus producing either a high (300 Vac ./ 400 Vdc) or low (150 Vac /
200 Vdc) output voltage range. Note that some configurations of the BPS Series may be hardwired for
single range use.
The modulator contains several feedback loops that control the current sharing and output regulation of
the four power amplifier boards. The Modulator boards connects to one of the three connectors on the
System interface through a 50 pin ribbon cable located at the top front of each power module.
