GaN HEMTs-based compact power factor corrected 96.1% peak efficiency LED driver with gate assisted circuit

Area of Science:

• Electrical Engineering
• Power Electronics
• Solid-State Lighting

Background:

• Modern LED drivers face challenges including low efficiency, large size, and reliability issues.
• Existing designs struggle with low operating frequency, voltage, and lack of fully soft switching.
• High power factor (PF), efficiency, and low total harmonic distortion (THD) are critical demands.

Purpose of the Study:

• To introduce a novel LED driver for high input voltage and low bus voltage applications.
• To address limitations such as noise, THD, and switching losses.
• To enhance reliability and power factor correction.

Main Methods:

• Implementation of two boundary conduction mode (BCM) boost circuits with a common inductor for natural PF correction.
• Integration of a novel gate-assisted circuit (GAC) to mitigate switching oscillations and shoot-through.
• Utilizing a transformer with independent secondary windings and a coupled inductor for dual LED string control.

Main Results:

• Achieved a total harmonic distortion (THD) of 11.2% and a power factor (PF) of 0.99.
• Demonstrated a peak power efficiency of 96.1% under full load.
• Confirmed fully soft switching operation with negligible switching losses and very low noise.

Conclusions:

• The proposed LED driver effectively overcomes common industry challenges.
• The design offers high PF, high efficiency, low THD, and enhanced reliability.
• The fully soft switching mechanism and GAC contribute to superior performance and reduced noise.