Active Power Factor Correction (APFC) Circuit with Dual-Loop Control Strategy

The Active Power Factor Correction (APFC) circuit utilizes a dual-loop control strategy featuring an outer voltage loop and an inner current loop, implemented through voltage and current sensors. During operation, these sensors continuously monitor real-time voltage and current variations in the circuit, enabling automatic regulation of both parameters to achieve power factor correction. Experimental results confirm that this circuit effectively performs power factor correction with high efficiency and precision characteristics. From a code implementation perspective, the control algorithm typically involves: - Voltage outer loop: Uses PI controllers to maintain DC bus voltage stability - Current inner loop: Implements PWM modulation techniques to shape input current waveforms - Sensor integration: ADC modules process real-time voltage/current measurements - Control logic: Implements power factor calculation algorithms and phase synchronization Key functions include: 1. Voltage regulation through error amplification and compensation 2. Current reference generation based on voltage loop outputs 3. Hysteresis or SPWM control for switching device modulation 4. Power factor computation using phase difference analysis between voltage and current signals The implementation demonstrates reliable performance with fast dynamic response and minimal harmonic distortion.