Rizqy Averous, Pablo Frack and Johannes Voss present their research in the IEEE PEDS Conference 2015, Sydney, Australia

09/06/2015

PGS team represented by Rizqy Averous, Pablo Frack and Johannes Voss participates in the 11th IEEE International Conference on Power Electronics and Drive Systems (PEDS 2015) held in Sydney Australia to discuss the ongoing research activities with the international communities. Three papers from different topics are presented by the PGS team in this conference. Detailed information on the presented papers can be found in the following abstracts.

 

Grid Emulator Requirements for a Multi-Megawatt Wind Turbine Test-Bench

Nurhan Rizqy Averous, Marco Stieneker and Rik W. De Doncker

Full-scale nacelle test-benches accelerate the development process of new multi-megawatt wind turbines. The device-under-test (DUT) is connected to an artificial grid that is emulated by a power-electronic converter system. Since the desired sinusoidal wave form of the voltage can only be approximated, filters have to be applied to suppress voltage harmonics sufficiently. But still, the output voltage is not purely sinusoidal due to a remaining share of harmonics. For the verification of the total harmonic distortion (THD) caused by the DUT, the influence of the grid emulator on the measurements of voltage and current has to be known. Otherwise the source of the harmonics cannot be identified clearly and the DUT might be characterized incorrectly. Within this work the requirements for grid emulators to allow the sufficiently high measurement of the THD caused by the DUT are derived analytically and validated with simulation models. Furthermore, the dynamic of voltage dips that have to be emulated to test the low-voltage ride-through (LVRT) capability of the DUT has to fulfil the established standards (IEC61400-21) for emulating a faulty grid realistically. The consequently derived requirements for the power electronic converters are presented within this paper

 

Emulation of Synchronous Machine for Frequency Stability Improvement in Microgrids

Pablo F. Frack, Rik W. De Doncker, Pedro E. Mercado, Marcelo G. Molina

Micro-grids (MG) are expected to be low inertia grids especially due to the deployment of power electronics used to connect distributed generation (DG) units. This issue brings consequences on the grid dynamics, reducing the frequency stability margins. To this end, the emulation of synchronous machines has been proposed as a possible alternative. This paper explores the benefits of this concept comparing the dynamic performance with respect to the conventional droop control.

 

High-Current Test-Bench for Thyristor-Based Semiconductors

Johannes Voss, Garrikoitz Sarregui, Fabian Rossbach, Rik W. De Doncker and Ander Ubillos

Increasingly thyristor-based converters (e.g. FACTS) are being integrated in the grids, to stabilize the distribution and transmission grids, due to the high power handling-capability of these semiconductor devices. Nevertheless, during faults, these converters need to withstand high circulating currents without failing. To investigate these scenarios, this paper presents a test bench to simulate different failure modes in a controlled environment. This test bench is able to generate symmetrical and asymmetrical sinusoidal currents up to 20 kA with a maximum duration of two seconds. Directly after the high current event, the voltage blocking capability of the thyristor is tested, by measuring the leakage current of the device under test under high voltage conditions (DUT).