Cycloconverter input-side power factor In practical operation, the input (supply-side) power factor of a cycloconverter is generally:

Introduction / Context:
Cycloconverters synthesize low-frequency output directly from the AC supply using phase-controlled thyristor bridges. Their supply current is highly non-sinusoidal and displaced, affecting the input power factor seen by the grid and influencing transformer sizing and utility penalties.

Given Data / Assumptions:

• Line-commutated cycloconverter (no DC link).
• Phase-controlled bridges with significant harmonic content.
• Typical industrial load (e.g., large synchronous or induction machine at low output frequency).

Concept / Approach:

Phase control introduces both displacement (due to firing angle) and distortion (harmonics) components. The net effect is a low overall power factor. Moreover, the fundamental input current typically lags the voltage (lagging PF) because the bridges draw current when line voltage is favorable, analogous to rectifier behavior, and reactive power is drawn due to commutation and harmonics.

Step-by-Step Solution:

Verification / Alternative check:

Utility experiences and textbooks report typical input PF values well below unity for cycloconverters, motivating filters or VAR support.

Why Other Options Are Wrong:

• “High” PF options (c, d) contradict heavy distortion and phase delay.
• “Leading” (a) is not characteristic of line-commutated bridges absent overcompensation or capacitive correction.

Common Pitfalls:

Assuming motor power factor dictates supply PF; in cycloconverters, the converter dominates.

Final Answer:

Low and lagging