| Paper |
Title |
Page |
| MOPAN002 |
Active Shunts for the LNLS Storage Ring Quadrupoles
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143 |
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- C. Rodrigues, A. R. Silva
LNLS, Campinas
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The quadrupoles of the LNLS storage ring are divided into families with two or six units, each one being supplied by an only current source. Some experiments performed by the accelerator physics team require different currents for quadrupoles of a same family. Moreover, there is an interest in obtaining lower steps in the control of their currents. These were the main reasons that required the development of an active shunt. A prototype was built with range of -3A to +3A, what is approximately 3% of the maximum quadrupole current (200A). It was tested with a two-quadrupole family power supply. The full bridge topology was chosen, where the pulse width for the positive and negative output voltages are not the same, which gives an average output current different from zero. Some waveforms and results are shown, such as the long-term stability and output current ripple. Some measurements made in the storage ring electron beam using the active shunt are also described.
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| MOPAN003 |
A New Family of Power Supplies for the LNLS Orbit Correctors
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146 |
| |
- C. Rodrigues, L. H. Oliveira, A. R. Silva
LNLS, Campinas
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Recently the substitution of the older family of orbit corrector power supplies of the LNLS electron storage ring was proposed and a new family has been developed. The new model incorporates additional features such as natural ventilation, unit power factor and shorter response time to reference changes. Moreover, higher efficiency and lower weight and size were obtained. At the moment eight units are operating with storage ring orbit correctors, with current and output voltage up to 10A/10V. This family has three stages of power processing. The first one is a power factor corrector using the boost topology, which gives to the second stage a DC voltage about 400V with regulation and ripple better than 1%. The second stage is an isolated half-bridge with two symmetric adjustable DC outputs from 0 to 40V. The last stage consists of a bipolar series linear regulator using Bipolar Transistors (BJT). Some results obtained for this power supply were: output current ripple and one day stability better than 150ppm, reference voltage step response better than 500A/s with the existing orbit corrector magnet, efficiency higher than 62% and power factor better than 98.5%.
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