Converter
AssigneeAlstom Grid UK Limited
InventorsDavid Trainer, Ruchira Withanage, Robert Whitehouse, Andrew Cross
Life of this patent
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Abstract
A multilevel voltage source converter for high voltage DC power transmission and reactive power compensation. The voltage source converter includes at least one phase element including a plurality of semiconductor switches to interconnect a DC voltage and an AC voltage. The voltage source converter also includes at least one auxiliary converter to act as a waveform synthesizer to modify the DC voltage presented to the DC side of the phase element.
Claims31
1-34. (canceled)
A multilevel voltage source converter for high voltage DC power transmission and reactive power compensation, the voltage source converter comprising:
- at least one phase element including a plurality of semiconductor switches to interconnect a DC voltage and an AC voltage;
- and
- at least one auxiliary converter to act as a waveform synthesizer to modify the DC voltage presented to the DC side of the phase element,
- wherein the or each auxiliary converter synthesizes a waveform closely approximating an offset rectified sinusoid waveform for presentation to the DC side of the or each phase element.
A method of controlling a voltage source converter including at least one phase element including a plurality of semiconductor switches to interconnect a DC voltage and an AC voltage, comprising:
- (i) modifying the DC voltage presented to the DC side of the or each phase element wherein the DC voltage is modified to present a waveform closely approximating an offset rectified sinusoid to the DC side of the or each phase element and the switches of the or each phase element are controlled to switch on and off at zero voltage;
- and
- (ii) controlling the semiconductor switches of the or each phase element to switch on and off in sequence in order to convert the modified DC voltage presented to the DC side of the phase element to an AC voltage.
Dependencies are inferred from the claim text.