Modified series inverter: attainable output frequency In a modified series inverter (using forced or auxiliary commutation extensions), how does the achievable output frequency compare with the natural damped resonant frequency of the L–C commutating network?

Introduction / Context:
Series inverters use resonant L–C commutation. Modified series inverters employ auxiliary switches/paths so that commutation is not limited strictly by the natural resonant period, enabling higher fundamental output frequency.

Given Data / Assumptions:

• Presence of a modified (assisted) commutation network.
• Switches and diodes ideal for conceptual analysis.
• Load is compatible with resonant current pulses.

Concept / Approach:
A basic series inverter's period is largely set by L and C, giving a damped oscillation with natural frequency f_d. By adding auxiliary commutation, the devices can be turned off and re-fired earlier than the natural half-cycle, effectively increasing the repetition rate of power pulses and therefore the output frequency.

Step-by-Step Solution:
Define natural frequency: f_d ≈ 1 / (2π * sqrt(L * C)) (ignoring damping).In a simple series inverter, switching follows this half-sinusoid → output frequency ties to f_d.Modified inverter introduces controlled commutation so that the next cycle can begin before the resonant current completely decays.Thus, achievable f_out can exceed f_d when designed to commutate early.

Verification / Alternative check:
Waveforms of modified circuits show shortened current pulses and increased repetition based on gating strategy rather than pure LC decay.

Why Other Options Are Wrong:
Less than / cannot exceed: True only for unassisted basic series inverters.
Any of the above: Over-broad and contradicts known capability of modified topologies.

Common Pitfalls:
Assuming natural resonance always caps frequency; in practice, controlled commutation can reshape intervals within device limits.

Final Answer:
the output frequency can be even higher than the frequency of damped oscillations