power factor correction of AC to DC converter

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power factor correction of AC to DC converter

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Power factor correction (PFC) in AC to DC converters is a crucial technique to improve efficiency and reduce harmonic distortion in power systems. When rectifying AC power to DC, conventional diode bridge rectifiers introduce significant reactive power and harmonics, degrading the power factor. PFC techniques help align the input current waveform with the input voltage, minimizing losses and complying with power quality standards.

### Key Concepts in PFC Simulation with MATLAB Boost Converter-Based PFC – A widely used topology where a boost converter is placed after the rectifier to shape the input current. It forces the input current to follow a sinusoidal waveform, improving power factor close to unity. Control Strategies – Common methods include average current control and peak current control using PWM techniques. MATLAB’s Simulink allows modeling these control loops with PI regulators and PWM generators. Harmonic Analysis – MATLAB’s FFT tools help analyze input current harmonics, ensuring compliance with standards like IEEE 519 or IEC 61000-3-2. Passive vs. Active PFC – Passive methods use LC filters, while active PFC (like the boost converter method) dynamically adjusts current. MATLAB simulations can compare their effectiveness.

### Simulation Approach Modeling the Rectifier & Boost Stage – Simulink’s Simscape Electrical library provides diode bridges, MOSFETs/IGBTs, and inductors for building the circuit. Implementing Control Logic – A voltage feedback loop maintains DC output, while a current loop shapes the input current. The reference current is derived from the input voltage waveform (often using a multiplier block). Performance Metrics – Evaluate power factor, THD (Total Harmonic Distortion), and efficiency under varying loads.

By simulating PFC in MATLAB, engineers can optimize component selection and control parameters before hardware implementation, ensuring efficient and compliant AC-DC conversion.

(Note: No explicit code was referenced; the focus is on methodology and theory.)