| Paper |
Title |
Page |
| MOPAN070 |
Developments in High-precision Aspects of Power Converter Control for LHC
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314 |
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- G. Fernqvist, M. C. Bastos, A. Cantone, Q. King
CERN, Geneva
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The initial results from integration testing of the LHC magnet power converters revealed problems of low-frequency noise, settling time, drift with time and temperature, thermal management and EMC. These problems originated in the use of DSP, the A/D converter (ADC), the DC Current Transducer (DCCT) and their respective environments. This paper reports the methods used to improve the performance through hardware and software modifications and the results achieved.
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| MOPAN071 |
Characteristics of Burden Resistors for High-precision DC Current Transducers
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317 |
| |
- G. Fernqvist, P. Dreesen, G. Hudson
CERN, Geneva
- J. R. Pickering
Metron, Norwich
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The DC current transducer (DCCT) and accompanying A/D converter determine the precision of a power converter in accelerator operation. In the LHC context this precision approaches 10-6. Inside the DCCT, a burden resistor is used to convert the current to an output voltage. The performance of this resistor is crucial for the accuracy, temperature behaviour, settling time and long-term drift of the DCCT. This paper reports on evaluations, a new parameter called "power coefficient" (PC) and test results from some different types of resistors available on the market.
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| MOPAN072 |
High-precision Performance Testing of the LHC Power Converters
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320 |
| |
- G. Fernqvist, M. C. Bastos, A. Cantone, P. Dreesen, O. Fournier, G. Hudson
CERN, Geneva
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The magnet power converters for LHC were procured in three parts, power part, current transducers and control electronics, to enable a maximum of industrial participation in the manufacturing and still guarantee the very high precision (a few parts in 10-6) required by LHC. One consequence of this approach was several stages of system tests: factory reception tests, CERN reception tests, integration tests, short-circuit tests and commissioning on the final load in the LHC tunnel. The majority of the power converters for LHC have now been delivered, integrated into complete converters and high-precision performance testing is well advanced. This paper presents the techniques used for high-precision testing and the results obtained. It is also hoped to report results from the first sector commissioning.
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