ESS lecture at Lund Tekniska Högskola
Title: ESS lecture at Lund Tekniska Högskolan
Location: John Ericssons väg 3, 223 63 Lund
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Description: The next Senior elevation meeting for IEEE Sweden Section is to be held in Lund at Kårhuset, LTH (John Ericssons väg 3, bus stop Sölvegatan 22a) Monday on the 7th of November. We are to start at 5 o’clock P. M. (17.00) with an ESS lecture (www.esss.se) presented by Professor Carlos A. Martins LTH, who is ESS Power Converters Work Package Leader. For those of you who apply for the IEEE Senior Grade, the Section will offer refreshments and sandwiches at about half past 6. At about 7 o’clock P. M. the formal elevation meeting, where competent references contribute, is to start.
Since the development origin of large scale particle accelerators in the 20ties, their powering systems have been amongst the most crucial elements of such large scale facilities.
After a short introduction to the principles of acceleration of charges particles and the role of electrical power converters in the fulfilment of basic movement profiles, the different types of electrical loads for such power converters and their function will be presented (Electro-magnets, High Voltage Radio Frequency Amplifiers).
Once the typical loads and their parameters have been understood, the presentation will then focus on the study of the different topologies suitable to realize such power converters and the challenges/requirements associated to them. Power Converters for Radio Frequency Amplifiers are High Voltage (up to 120 kV, typically) and high power (several MW). Power converters for electro-magnets are high current (several kA tens kA) and low voltage (tens to hundreds V). All might be pulsed or DC, depending on the nature of the accelerator and have requirements typically very difficult to combine – high power, high bandwidths and high precision. The power levels limit the choice of semiconductor components’ technology; the high bandwidth requirements orient the solution towards high switching frequencies, which might be difficult to achieve with some semiconductors. High precision also requires high switching frequencies, high quality on the measurements and low EMI. Besides the requirements on the load side, challenging requirements, related to power quality are also present on the AC-grid side. Indeed, pulsed loads have tendency to generate flicker. Depending on the adopted topologies and technology choices, current harmonic distributions might be also an important factor to account for. To meet all these contradictory requirements innovative topologies have been developed for the ESS accelerators with unprecedented expected performance at a worldwide scale, not only in relation to the main requirements, described above but simultaneously on cost and power density. Some examples of prototype developments and results obtained so far will be shown:
- HV klystron modulator, rated for 115 kV/20 A, pulsed with 3.5 ms (pulse width) and 14 Hz (pulse repletion rate)
- The pulsed power converters for quadrupole focusing magnets, rated for 1 kV/400 A, pulsed with 4 ms (flattop duration) and 14 Hz repetition rate.
The ESS accelerator will require 33 units of the first type and 13 units of the second type, amongst others,.The European Spallation Source is a Partnership of 17 European Nations, committed to the goal of collectively building and operating the world’s leading facility for research, using neutrons by the second quarter of the 21st century.
Start Time: 17:00
End Time: 19:00