18691432. CHARGING OF A MODULAR MULTILEVEL CONVERTER (Hitachi Energy Ltd)
CHARGING OF A MODULAR MULTILEVEL CONVERTER
Organization Name
Inventor(s)
Jean-Philippe Hasler of Västerås (SE)
CHARGING OF A MODULAR MULTILEVEL CONVERTER
This abstract first appeared for US patent application 18691432 titled 'CHARGING OF A MODULAR MULTILEVEL CONVERTER
Original Abstract Submitted
A method of pre-charging a modular multilevel converter (MMC) is provided, including interrupting a normal, first current flow path between the MMC and the electric grid, providing an alternative, second current flow path between the MMC and a power source, pre-charging, via the second current flow path, the capacitors in the converter cells of the converter valve to a first voltage level below a peak voltage magnitude of the electric grid but sufficient to power the valve control unit, after reaching the first voltage level, setting the voltage reference to a finite voltage having a magnitude lower than the peak voltage magnitude of the power source and thereby, using the valve control unit, boosting the capacitors in the converter cells of the converter valve to a second voltage level having a magnitude at least equal to or higher than the peak voltage magnitude of the electric grid.