Comparing 3-phase semiconverter and 3-phase full converter (same load) If a 3-phase semiconverter gives rectification efficiency ≈ 0.6 and transformer utilization factor (TUF) ≈ 0.35 for a given load, how do these figures change when a 3-phase full converter supplies the same load?

Introduction / Context:
Three-phase rectifiers are evaluated by rectification efficiency (conversion of AC to useful DC) and transformer utilization factor (how effectively the transformer VA rating is used). A full converter uses six controlled devices and both halves of the AC waveform more effectively than a semiconverter.

Given Data / Assumptions:

• Same load conditions for fair comparison.
• Semiconverter: rectification efficiency ≈ 0.6, TUF ≈ 0.35.
• Full converter: six-pulse, controlled on both polarities.

Concept / Approach:
The full converter provides a higher average DC output for a given RMS transformer current and spreads conduction among phases more uniformly, improving both rectification efficiency and transformer utilization.

Step-by-Step Solution:
Compare output DC levels: full converter achieves larger controllable average DC voltage magnitude.Compare transformer loading: full converter’s conduction pattern yields better TUF.Thus both metrics improve over the semiconverter.

Verification / Alternative check:
Standard tables for power converters list higher TUF and efficiency for full converters than for semiconverters under comparable conditions.

Why Other Options Are Wrong:
Mixed better/worse claims: Do not reflect typical performance trends for the same load.

Common Pitfalls:
Confusing “efficiency” with power factor; power factor behavior differs, but the question asks rectification efficiency and TUF.

Final Answer:
rectification efficiency will be more than 0.6 and TUF will be more than 0.35