Pulse number of a three-phase fully controlled bridge converter A three-phase fully controlled rectifier (bridge) is classified as a __-pulse converter. Select the correct pulse number.

Introduction / Context:
Converters are often identified by their pulse number, which equals the number of DC output ripple pulses per input cycle. This metric affects harmonic content and filtering requirements.

Given Data / Assumptions:

• Three-phase full bridge using six controlled devices (e.g., SCRs).
• Standard three-phase line voltages with 120° displacement.

Concept / Approach:
In a three-phase full bridge, each device conducts for 120°, and commutation occurs every 60°. Hence, six pulses of DC ripple are produced each line cycle, giving a 6-pulse converter.

Step-by-Step Solution:
Identify commutation every 60° → six commutations per cycle.Each commutation produces a distinct ripple pulse on the DC side.Therefore, “6-pulse” classification applies.

Verification / Alternative check:
Harmonic spectra of 6-pulse converters display characteristic orders at 6k ± 1 on the AC side.

Why Other Options Are Wrong:
3-pulse/2-pulse: Associated with single-phase or half-wave arrangements.
12-pulse: Requires two 6-pulse bridges with phase-shifting transformer.

Common Pitfalls:
Confusing the number of switches with the pulse number; pulse number is tied to commutation per cycle.

Final Answer:
6-pulse converter