CONTROLLED INRUSH CURRENT FOR CONVERTER-CONNECTED GRID FILTER

• Main Authors: Nielen, John Godsk, HELLE, Lars, ANDERSEN, Gert Karmisholt, Pedersen, Tune, ANDERSEN, Søren, ABEYASEKERA, Tusitha, DOAN, Duy Duc
• Format: Patent
• Language: English
• Published: 26.04.2018
• Subjects: BLASTING; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; HEATING; LIGHTING; MACHINES OR ENGINES FOR LIQUIDS; MECHANICAL ENGINEERING; OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR; PRODUCING MECHANICAL POWER; SYSTEMS FOR STORING ELECTRIC ENERGY; WEAPONS; WIND MOTORS; WIND, SPRING WEIGHT AND MISCELLANEOUS MOTORS

A method, converter arrangement, and controller are disclosed for connecting an output of a converter with an electrical grid to control inrush currents into a grid filter assembly connected with the output of the converter, the electrical grid carrying an alternating current (AC) signal having one or more phases. The method includes determining a voltage of the AC signal and operating, after pre-charging a direct current (DC) link of the converter to a predetermined voltage, the converter using open-loop voltage control to produce an AC output signal that substantially matches the AC signal of the electrical grid. The open-loop voltage control is based on the determined voltage of the AC signal. The method further includes closing, after a predetermined amount of time of operating the converter using the open-loop voltage control, a switching device to thereby connect the output of the converter with the electrical grid.