Lab-scale experimental multilevel modular HVDC converter with temperature controlled cells

It is important to be able to produce representative experimental results when researching HVDC grids and converters. This paper reports on a lab-scale multi-level converter build. The converter was built with a large number of cells to enable experiments with cell balancing effects and with temperature control to investigate thermal effects and appropriate responses. The converter is able to behave as both a traditional MMC (or CTLC which is functionally similar) and as the newer AAC converter. Results are presented that show the converter is able to charge up from the DC bus and is able to function well with both static and changing power references.