| |
Controlling the AC-Side Voltage Waveform in a Modular Multilevel Converter With Low Energy-Storage Capability
| [View]
[Download]
|
| Author(s) |
Kalle ILVES, Antonios ANTONOPOULOS, Staffan NORRGA, Lennart ÄNGQUIST, Hans-Peter NEE |
| Abstract |
During nominal operation of a modular multilevel converter the stored energy in the submodule capacitorswill vary with time. If the energy storage capability of the capacitors is relatively small comparedto the energy variations, this will give large variations in the capacitor voltages. These voltage variationswill distort the ac-side voltage waveform and induce harmonic components in the current that is circulatingbetween the dc terminals. The adverse effects on the ac-side voltage can be compensated for byidentifying the factors that cause the distortion. It is shown that the compensation can be done by meansof feed forward control while maintaining stable operating conditions and thus eliminating the need ofadditional stabilizing controllers. It is also shown that the voltage controller can be combined with acirculating current controller that removes the harmonics in the current that is circulating between the dcterminals. The functionality of the proposed controller is verified by both simulations and experimentalresults from a 10 kVA laboratory prototype. The simulations illustrate how the proposed controllersuccessfully removes the distortion from the ac-side voltage waveform. The experimental results demonstratestable operation during a step transient when the output power is increased by 125\%. |
| Download |
| Filename: | 0430-epe2011-full-10294814.pdf |
| Filesize: | 750.4 KB |
|
| Type |
Members Only |
| Date |
Last modified 2012-01-26 by System |
| |
 |