| 摘要 |
A voltage source converter 30 for connecting a DC network 44 to an AC network 46 comprises a plurality of converter limbs 36 between DC terminals, each having first and second limb portions 38,40 separated by an AC terminal 42 for connection to a phase of the AC network. (46). Each limb portion includes a valve 50 comprising at least one switching element and at least one energy storage device (fig. 2). The switching element of each valve can selectively insert or bypass the energy storage device, (e.g. capacitor, fuel cell, battery) to control a voltage across that valve. A controller 62 controls selected valves of two of the converter limbs to form a current circulation path including the limb portions corresponding to the selected valves, the AC phases connected to the limb portions and the DC network such that a circulating alternating current flows through the current circulation path. The controller controls the switching of the selected valves to control the phase angle and amplitude of a AC component of the circulating current to control the amount of energy transferred to or from each selected valve. Each valve may comprise a plurality of modules defining a chain-link converter. |
