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An enhancement of the six-pulse bridge arrangement uses 12 valves in a twelve-pulse bridge. [11] A twelve-pulse bridge is effectively two six-pulse bridges connected in series on the DC side and arranged with a phase displacement between their respective AC supplies so that some of the harmonic voltages and currents are cancelled.
At 12 pulse converter stations, only harmonic voltages or currents of the order 12n + 1 and 12n - 1 (on the AC side) or 12n (on the DC side) result. Filters are tuned to the expected harmonic frequencies and consist of series combinations of capacitors and inductors.
Long distance HVDC lines carrying hydroelectricity from Canada's Nelson River to this converter station where it is converted to AC for use in southern Manitoba's grid. A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. [1]
A twelve-pulse bridge consists of two six-pulse bridge circuits connected in series, with their AC connections fed from a supply transformer that produces a 30° phase shift between the two bridges. This cancels many of the characteristic harmonics the six-pulse bridges produce.
q = pulse number (6, 12 . . .) f o = output frequency of the CCV; Equation's 1st term represents the pulse number converter harmonic components starting with six-pulse configuration; Equation's 2nd term denotes the converter's sideband characteristic frequencies including associated interharmonics and subharmonics.
A thyristor (/ θ aɪ ˈ r ɪ s t ər /, from a combination of Greek language θύρα, meaning "door" or "valve", and transistor [1]) is a solid-state semiconductor device which can be thought of as being a highly robust and switchable diode, allowing the passage of current in one direction but not the other, often under control of a gate electrode, that is used in high power applications ...
The average output voltage is directly proportional to the ON time of chopper. The ratio of ON time to total time is defined as duty cycle. It can be varied between 0 and 1 or between 0 and 100%. Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a technique used to encode a message into a pulsing signal.
The Bipole 2 transmission line runs 937 kilometres (582 mi) from Henday to Dorsey. Bipole 2 can transfer a maximum power of 1800 MW at a potential of ±500 kV. Bipole 2 consists of four 12-pulse converter groups at each end (two in series per pole) and was put into service in two stages. After the first stage in 1978 the maximum power was 900 ...