Multivariable control of MMC-based Static converters for railway applications

Actually, new static-converter stations are build as modular multilevel converters (MMC) to feed the AC 16.7-Hz railway grids from the public grid. In order to cope with the high dynamic requirements of railway grids, dynamic control concepts are a must. In this paper, a multivariable control concept is presented which utilizes pole-restraining control. The dynamic behaviour is analysed under different dynamic situations concerning load and grid-voltage changes.