Govt. Exams
Entrance Exams
ΔIL = (Vin × D × (1-D))/(L × f). Assuming standard inductor ~10μH: ΔIL ≈ (48 × 0.7 × 0.3)/(10e-6 × 500e3) ≈ 2.4A.
MMC offers scalability, modularity, and superior voltage quality for utility-scale applications, making it the industry standard for >100kW systems.
Conduction loss = I²rms × RDS(on). With 50A average current (≈35.4A RMS) and 0.5Ω: Loss ≈ (35.4)² × 0.5 ≈ 625W. At high frequency, peak current factor increases loss to ~1250W.
ZVS eliminates capacitive discharge losses during switching, significantly reducing switching losses and high-frequency EMI emissions.
For AC voltage controller: PF = (1/π)√(π² - 4α²) × sin(2α)/(2α) where α = 30° = π/6. This yields PF ≈ 0.87 with leading reactive current.
Minimum OFF-time must account for semiconductor recovery characteristics: tOFF(min) = ts + tf, allowing complete device turn-off before the next cycle.
Commutation overlap occurs due to finite source impedance. The overlap angle μ = sin⁻¹(ωLₛI/√2×Vline), depending on source inductance and current.
For half-wave rectifier: Vrms = (Vm/2)√[(π - α + sin(2α))/(2π)] where α = 45° = π/4, Vm = 230√2 = 325.3V. Vrms ≈ 108.6V
Latch-up in CMOS and power devices occurs when parasitic p-n-p and n-p-n transistors form a regenerative feedback loop, causing high current and potential device destruction
Synchronous rectifier gate drive must be timed with the primary switch to replace the body diode conduction, typically during the primary switch OFF period
