ANORDNING FOR ENDRING AV FASFORSKJUTNINGEN MELLAN ELEKTRISKA NETSPENNINGAR

摘要

1493652 Phase shifting OTDEL ENERGETICHE KIBERNE AKAD NAUK MOLDAV SSR 22 July 1975 [22 July 1974 (4)] 30665/75 Heading H2F A phase shifter comprises at least two threephase multi winding transformersα, # each having primary windings W 1α, W 1 # connected in series for each phase and control windings Wcα, Wc#, the first three-phase transfomerαbeing provided with two groups of secondary windings W 2α, W1 2αand the second transformer # consisting of a single group of windings W 2 #, the control windings being connected to respective switching devices 3, 4 which are able to short the control windings to adjust the phase angle between the sets of output voltages E1 A -E1 C and E11 A -E11 C . The switching devices consist of opposed thyristors (7, 8), Fig. 17 (not shown) and diodes (9, 10) so that when both the switching devices are off the phase angle between the sets of output voltages is 60 degrees. When the device 3 is switched on to short circuit the control windings for the first transformer and the device 4 is off, the phase angle is zero and the transformer system supplies low power loads. When the device 4 is switched on to short circuit the control windings of the second transformer and the device 3 is off, the phase angle between the sets of output voltages is 120 degrees and the transformer system supplies high power loads. In a modification the windings W 2 # are delta connected to give phase shifts of 90 and 180 degrees and the first transformer may have a third group of secondary windings.