Summary
High performance power supplies are used in a wide variety of applications ranging from telecommunication equipment, industrial equipment, digital televisions, lighting, air conditioners and other home appliances. They all need solutions for power factor correction to improve overall efficiency, improve the input power factor, voltage regulation and Total Harmonic Distortion (THD) of the input current. Digital interleaved power factor correction methods provide many benefits over older PFC techniques including:
- Lower Cost for High Power Applications
- Smaller PFC Inductor and Magnetic volume
- Higher Power Density
- Lower Ripple
- Easy implementation of sophisticated control algorithms
- Flexible software modifications to meet specific customer needs
- Simpler integration with other applications
This reference design provides an easy method to evaluate the power, and features of SMPS dsPIC
Digital Signal Controllers for an Interleaved Power Factor Correction application. The Interleaved PFC reference design unit works with universal input voltage range, and produces a single high voltage DC output up to 350W of power. The reference design has six main blocks:
- Input EMI filter and rectifier,
- Dual Phase Interleaved PFC Circuit with feedback,
- Plug in module connector with a dsPIC33FJ16GS504,
- User’s interface circuit with programming connector and push buttons,
- 12V and 3.3V power supply circuit, and
- Fault detection circuit for hardware protection.
The dual phase interleaved PFC software implements three compensators for voltage, current and load balancing. It also has a feed-forward compensator based on input average voltage.
Features
Key features of Interleaved PFC Reference Design
- Operates at universal input voltage (85-265Vac, 45-65Hz)
- Operates up to 350W sustained output
- Output voltages up to 400Vdc
- Power factor correction of 0.998 at full load and 120VAC input
- Current Total Harmonic Distortion (ITHD) of 3% at full load and 120VAC input
- Fault protection