Speaker
Markus Teschke
(E1 - tokamak scenario development)
Description
BUSSARD is a new inverter system at the nuclear fusion experiment ASDEX Upgrade for mitigation of ELMs and execution of other, physics related experiments. The concept and first results were presented in detail [1]. Four-phase operation was routinely done during shot campaign 2015/16 and many experience in operation was gained. Now, the completion of BUSSARD is almost finished and many improvements were adapted. 16-phase operation with up to 16x 1.3 kA coil current of arbitrary waveform controlled by 16 independent real-time controllers at 500 Hz bandwidth, 5 kHz switching frequency and about 1 MW/10 Mvar total real/reactive power will be commissioned within the current campaign. In this publication, three main topics are discussed: (i) Simulations, (ii) re-design of interface cards and (iii) the new in-house developed GUI (graphical user interface) for efficient handling of BUSSARD.Different kinds of SPICE-based models were developed and verified with experimental data. A “global model” describes the whole electric system with focus on power distribution and power circulation between sources and loads. Here, the 16 inverters can be fed by realistic reference curves, but they are approximated by simplified electrical models. This reduces calculation time and the model is helpful for quick trouble-shooting, optimization of main thyristor rectifier controllers and identification of valid working regimes. Another model describes the behaviour of quick switching power electronics and its electrical environment in detail. Such model requires more computing resources but it was important during design phase of BUSSARD. A third model was developed for improvements of PWM scheme and fast real-time controlling algorithms.The re-design of interface cards comprehends additional disturbance suppression, optimization of grounding schemes and potential separation, improvements in fail-safe handling of critical safety-relevant signals and optimizations of PLD-related firmware.[1] M.Teschke, et al., Fusion Eng. Des. (2015) 171–176
Co-authors
Horst Eixenberger
(E1 - tokamak scenario development, Max Planck institute for plasma physics, Garching, Germany)
Markus Teschke
(E1 - tokamak scenario development, Max Planck institute for plasma physics, Garching, Germany)
Michael Rott
(E1 - tokamak scenario development, Max Planck institute for plasma physics, Garching, Germany)
Nils Arden
(E1 - tokamak scenario development, Max Planck institute for plasma physics, Garching, Germany)
Wolfgang Suttrop
(E1 - tokamak scenario development, Max Planck institute for plasma physics, Garching, Germany)
