Abstract:
A circuit for a hybrid voltage source converter suitable for high voltage DC power transmission and reactive power compensation. The circuit comprises an assembly of electrically interconnected elements (Elements 1 to 20) including a plurality of first elements (Elements 1 to 6) and a plurality of second elements (Elements 7 to 20). Each of the first and second elements is configurable to be bypassed, to be disconnected or to include a circuit arrangement of one or more electronic components to construct, in use, a hybrid voltage source converter including at least one first element and at least one second element and in which the circuit arrangement included in the or each first element is different to the circuit arrangement included in the or each second element.
Abstract:
A circuit breaker for high voltage direct current (HVDC) power transmission includes a module with a pair of terminals for connection to an electrical network, and four of conduction paths. Each first conduction path includes a mechanical switch connected in series with at least one first semiconductor switch to selectively allow current to flow between the first and second terminals through the first conduction path in a first mode of operation or commutate current from the first conduction path to the second conduction path in a second mode of operation. The second conduction path also has a semiconductor switch to selectively allow current to flow between the terminals through the second conduction path or commutate current from the second conduction path to the third conduction path in the second mode of operation. The third conduction path has a snubber circuit with an energy storage device to control a rate of change of voltage across the mechanical switch and oppose current flowing between the first and second terminals in the second mode of operation. The fourth conduction path has a resistive element to absorb and dissipate energy in the second mode of operation and divert charging current from the first and second terminals away from the energy storage device to limit a maximum voltage across the pair of terminals.
Abstract:
A voltage source converter for high voltage DC power transmission is disclosed. According to one aspect, the voltage source converter is connectable between a DC network and another electrical network to interconnect the DC network and the other electrical network. The voltage source converter includes a converter unit configured to convert power flowing between the DC network and the other electrical network and at least one fault unit. One or more of the fault units includes at least one fault module having a voltage source that is operable, in the event of a short circuit in a DC network connected to the voltage source converter, to produce a voltage that acts to reduce current flowing through the voltage source converter and the short circuit.
Abstract:
A power electronic converter for use in high voltage direct current power transmission and reactive power compensation which includes at least one converter limb including first and second DC terminals for connection in use to a DC network. The or each converter limb includes at least one first converter block and at least one second converter block connected between the first and second DC terminals. The or each first converter block includes a plurality of line-commutated thyristors and at least one first AC terminal for connection in use to an AC network. The or each second converter block includes at least one auxiliary converter including a plurality of self-commutated switching elements. The self-commutated switching elements are controllable in use to inject a voltage to modify a DC voltage presented to the DC side of the converter limb and/or modify an AC voltage and an AC current on the AC side of the power electronic converter.