| 主权项 |
1. A voltage source converter comprising:
a converter limb extending between first and second DC terminals and having first and second limb portions separated by an AC terminal, the first and second DC terminals being connectable to a DC electrical network and the AC terminal being connectable to an AC electrical network, each limb portion including at least one switching element; a chain-link converter including a plurality of series-connected modules, each module including at least one switching element and at least one energy storage device, the or each switching element and the or each energy storage device of each module combining to selectively provide a voltage source, the chain-link converter being connected to the AC terminal, the or each switching element of each limb portion being switchable to switch the chain-link converter into and out of circuit with that limb portion and thereby switch the chain-link converter into and out of circuit with the corresponding DC terminal; and a control unit which coordinates the switching of the switching elements of the limb portions and the or each switching element in each module of the chain-link converter to transfer power between the AC and DC electrical networks, wherein the control unit controls the switching of the or each switching element in each module of the chain-link converter to generate an AC voltage waveform at the AC terminal, the AC voltage waveform including an AC voltage waveform portion between positive and negative peak values of the AC voltage waveform, the AC voltage waveform portion including at least two different voltage profiles to filter one or more harmonic components from the AC voltage waveform, at least one of the different voltage profiles being defined by a non-zero voltage slope. |
