Loading patent…
AssigneeABB Schweiz AG
InventorsFrederick Kieferndorf, Mario Schweizer, loannis Tsoumas
Estimating the term…
An electrical converter (10) comprises a main stage (12) adapted for converting a DC voltage into an intermediate voltage comprising at least two voltage levels and a filter cell stage (14) with a filter cell (30) for each phase of the main stage (12), each filter cell (30) being adapted for adding or subtracting a cell voltage of the filter cell (30) to the intermediate voltage. A method for controlling an electrical converter (10) comprises a pattern determination part (44) comprising the steps of: selecting and reading an offline-computed optimized pulse pattern (OPPbase) from a database, wherein the selected optimized pulse pattern (OPPbase) comprises switching instants for the main stage (12) and the filter cells (30) over a next computation window (αwin) of a predetermined width (αw); adjusting the optimized pulse pattern (OPPbase) by moving its switching instants such that average output voltages generated in the filter cells (30) are shifted towards an average output voltage reference (Ubal,abc) of the filter cells (30), which is determined from measurements in the filter cells (30), and compensating these adjustments by corresponding modifications of switching instants of the main stage (12). The method comprises further a model predictive control part (46) comprising the following steps, which are performed several times during the next computation window (αwin): modifying the adjusted optimized pulse patterns (66) by moving at least one transition time of a switching instant, such that a flux error determined from a difference between an estimated flux (74) of the electrical converter (10) and a reference flux trajectory (Ψref) is minimized; and applying at least a next switching instant from the modified adjusted pulse pattern to the electrical converter (10).
A method for controlling an electrical converter, the electrical converter comprising a main stage having an output comprising at least three phases of an intermediate voltage, the main stage configured to convert a DC voltage into the intermediate voltage, the intermediate voltage comprising at least two voltage levels, and a filter cell stage with a filter cell for each phase of the main stage, each filter cell configured to add or subtract a cell voltage of the filter cell to the intermediate voltage,
A computer program for controlling an electrical converter, the electrical converter having a main stage having an output comprising at least three phases of an intermediate voltage and the main stage configured to convert a DC voltage into the intermediate voltage, the intermediate voltage comprising at least two voltage levels, and a filter cell stage with a filter cell for each phase of the main stage, wherein, when the computer program is executed by a processor, the computer program is configured to:
A controller configured to control an electrical converter, the electrical converter having a main stage having an output comprising at least three phases of an intermediate voltage, and a filter cell stage with a filter cell for each phase of the main stage, the controller comprising:
Dependencies are inferred from the claim text.