-
A single phase full-wave half-controlled bridge converter feeds an inductive load. The two SCRs in the converter are connected to a common DC bus. The converter has to have a freewheeling diode
-
- because the converter inherently does not provide for free-wheeling
- because the converter does not provide for freewheeling for high values of triggering angles
- or else the free-wheeling action of the converter will cause shorting of the AC supply
- or else if a gate pulse to one of the SCRs is missed, it will subsequently cause a high load current in the other SCR
Correct Option: B
Fig. Single-phase bridge type semi-converter: (a) circuit diagram, and (b) waveforms.
During the free-wheel period, π to (π + α), and 2π to (2π + α), energy stored in Inductance during (π + α) to π and α to π, gets dissipated partially in R and partially to the energy stored in load emf E. No energy is fed back to the source during free-wheeling period.
Therefore, in the absence of free-wheeling diode, T1 and T2 may conduct simultaneously which will came short-circuit of supply voltage VS.
