Half-bridge inverter output frequency vs. device gating frequency A single-phase half-bridge inverter gates each thyristor at a frequency f with 180° conduction (no PWM). What is the fundamental output frequency delivered to the load?

Introduction / Context:
In a half-bridge inverter, two complementary switches (thyristors or transistors) connect the output alternately to +Vdc/2 and −Vdc/2. The relationship between the gating frequency per device and the fundamental output frequency is essential for designing control and filters.

Given Data / Assumptions:

• Each device conducts for half a cycle (180° conduction).
• No PWM or modulation; simple square-wave operation.
• Complementary gating; dead-time negligible for this ideal discussion.

Concept / Approach:

When the top device turns on, the output is +Vdc/2 for half a period; when the bottom device turns on, the output is −Vdc/2 for the next half period. Each device turns on once per output cycle. Therefore, the per-device gating repetition rate equals the output fundamental frequency.

Step-by-Step Solution:

Verification / Alternative check:

Waveform analysis: the square wave has a period equal to the time between consecutive ON instants of the same switch, identical to the gating period.

Why Other Options Are Wrong:

(a) Implies two device turns per period per device, which is not the 180° scheme. (c) and (d) contradict the basic two-step per cycle operation.

Common Pitfalls:

Confusing total switching events per cycle (two across both devices) with per-device gating frequency.

Final Answer:

f