ABB ACS880-07LC, Руководство по оборудованию

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Overview diagram of the rectifier bridge
U U
1
2
3
Diodes. The diodes connect the AC terminals in cyclic sequence to the lower DC busbar (-). 1
Thyristors. The thyristors connect the AC line terminals in cyclic sequence to the upper DC busbar (+). 2
AC chokes 3
12-pulse connection (A004)
The figure below illustrates the difference between 6-pulse and 12-pulse AC supply
connections. 6-pulse connection is standard.
Some drive types are available as a 12-pulse version (A004).
The 12-pulse supply connection eliminates the fifth and seventh harmonics, which
substantially reduces the harmonic distortion of the line current and the conducted emissions.
The 12-pulse connection requires a three-winding transformer, or two separate transformers.
There is a phase shift of 30-degrees between the two 6-pulse supply lines, which are
connected to different supply modules through electrically separate switching equipment.
Operation principle and hardware description 29