High Voltage Power Supplies
In a DC accelerator the high voltage supply is the most complex and
expensive part that largely determines the equipment depreciation,
accelerator efficiency and its radiation cost. In the process of achieving
self-reliance and developing the expertise in this high technology area we
have successfully completed following jobs.
50
kV/100 mA Rotating Anode X-ray Generator Power Supply [ Go to Top ]
This high voltage power supply, developed in 1990-91, was donated to Vikram
University, Ujjain along with rotating anode x-ray generator RAX-5. The unit
consists of a -50 kV/100 mA H.V. supply and 10V/10A filament power supply,
floating at -50 kV. A two-stage symmetrical voltage multiplier is fed from a
5kHz/ 5kW solid-state inverter through a (9-0-9) kV ferrite core transformer
for generating the high voltage.
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50 kV/50 mA Rotating Anode X-ray
generator and its power supply |
60
kV/ 100 mA Rotating Anode X-ray generator power supply [ Go to Top ]
This power supply, developed in 1992 - 93, is based on single phase, 50Hz,
primary phase control scheme and presently being used by SRS utilization
group in RRCAT. The unit basically combines three supplies viz., a 60 kV/ 100
mA high voltage p/s, a 10V/13A filament p/s and a 1000V/10 mA bias voltage
p/s. The output parameters are stabilized with in 0.1% for the specified
range of input and load variations.
15 kV/50
mA Dual Anode Soft X-ray Source Power Supply [ Go to Top ]
The dual anode soft x-ray source power supply for ESCA facility was
successfully commissioned at Metallurgy Division BARC on 30th Nov. 1994. The
unit consists of a zero to 15 kV (DC) thyristor controlled HV power supply
and a dual port, current controlled, dc filament power supply with emission
stabilization circuits for both the filaments.
The dual filament power supplies rated for 5 V/8A dc are series regulated,
so as to ensure a stable emission current. Zero to 25 mA emission current of
individual filaments can be set by digital reference circuits with the help
of UP/Down switches.
400 kV/10mA
Deuteron Accelerator Power Supply [ Go to Top ]
This power supply required by Neutron Physics Division for neutron generator
project was installed in Purnima laboratory of BARC in July 1998. The power
supply is developed with an eight stage balanced multiplier stack, fed from
a 5kHz / 5kW sine wave inverter. Corona guard rings and HV dome of adequate
size and shape are provided for stress control and guarding of internal
components. HV output is controlled and regulated by varying the inverter
output voltage in a closed feed back loop. The terminal voltage is sensed
via a 400 kV resistive divider developed in house.
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| 400
kV assembly |
750 kV/25mA D. C.
Accelerator power supply [ Go to Top ]
This power supply is required for 750keV industrial electron accelerator,
developed at our centre. Utilizing the advantages of high frequency based
multiplier schemes, the power supply is developed with a fifteen stage
balanced multiplier stack, fed from a 40 kHz/ 40kW IGBT based sine wave
inverter. The complete multiplier structure is housed in a pressure vessel
along with acceleration column at 5 atmospheric pressure of SF6. The
filament power supply required for the generation and control of the
electron beam is floating at 750kv. Control of this auxiliary supply is
achieved through optical fibers from a PC based control console. High
voltage output is controlled and regulated by varying the inverter output
voltage in a closed feed back loop. The terminal voltage is sensed via a 750
kV resistive divider developed in house.
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Assembly of 750 kV multiplier stack |
LabView Based
Computer Control of DC Accelerator [ Go to Top ]
Initially the computer control of DC accelerator was done using GUI software
written in C++ language and micro controller 8051. This system
has been upgraded to make it compatible with Lab View software, which is far
more superior to the previous one. A 4-channel analog and 13-channel digital
input card based on parallel port has been developed for the monitoring of
different signals of the machine. The control system is based on RS485
multi-drop communication link along with ADµC 812 micro controller cards.
Each card contains 8-channel analog input, 2-channel analog output and 16
digital IOs. Interfacing of these cards with PC is done using Lab-view
software. A proprietary protocol for the communication purpose between cards
and PC has been developed. Development of the new micro-controller card
based on ADµC 812 has been a remarkable job in this work.
4.2 kV, 5 mA
Current Controlled Power Supply [ Go to Top ]
This power supply has
been designed and developed for testing of fast acting vacuum valve being
developed in PL&VT lab. The supply uses a current mode controller IC 3844
for regulating the output current at 5 mA in case of a short circuit at the
output. The 230 V mains input is rectified and filtered to generate the dc
input to the high frequency fly-back chopper circuit which generates 2 kV
regulated output through a high voltage ferrite core transformer.
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