Chonnam National University Researchers Propose Innovative Voltage-Loop Control for Power Factor Correction

JEOLLANAM-DO PROVINCE, South Korea, Dec. 18, 2025 /PRNewswire/ — Single-phase power factor correction (PFC) circuits—a kind of front-end AC/DC converters—are ubiquitous in a variety of consumer electronic devices, including laptop adapters, LED driver power supplies, and portable chargers. They enhance the current quality drawn from the source, delivering stable DC voltage with high efficiency.

However, current sensors in traditional boost PFC converters introduce issues such as noise susceptibility, signal delays, increased hardware complexity, and potential sensor failures that can degrade system reliability and lifespan. By eliminating current sensors, the proposed sensorless strategy reduces these risks, improves noise immunity, and decreases hardware failure points, leading to enhanced reliability and potentially longer-lasting power adapters and consumer electronics.

In a remarkable breakthrough achievement, a team of researchers from South Korea and China, led by Sung-Jun Park, a Professor from the Department of Electrical Engineering at Chonnam National University, has successfully demonstrated a new control method that eliminates the need for a current sensor. Their findings were made available online and have been published in the journal IEEE Transactions on Consumer Electronics on 30 September 2025.

In this study, the team proposes a simple and reliable single voltage loop current sensorless PFC control strategy. They derive the expression for the duty cycle—which consists of a feedforward component and a control component—by leveraging the fundamental equation of inductor voltage. Notably, delay compensation helps mitigate the effect of phase delay on input current distortion in the proposed control strategy.

“In this way, we specifically identified and solved a common issue in digital control systems: phase delay caused by signal processing. This delay distorts the input current. Our built-in compensation technique effectively counteracts this, which is a key reason for our method’s high-power quality,” remarks Prof. Park.

The novel technology eliminates complex observers and mathematical models, resulting in lower component cost, simpler circuit design, and a smaller size. This reduces maintenance by minimizing parts prone to wear or recalibration, enhancing long-term efficiency compared to sensor-based solutions. Additionally, its low sensitivity to circuit parameter variations ensures reliability and suitability for mass production, allowing manufacturers to easily integrate the control strategy into existing production lines using standard digital signal processors without major redesign or added inventory.

This technology suits AC/DC power supplies in consumer electronics, validated on a 1.3 kW prototype achieving near-unity power factor (up to 0.9998) and low total harmonic distortion (THD) (2.12% at full load)—matching or exceeding sensor-based methods. By eliminating sensors and components, it enables smaller, cost-effective designs. Prof. Park explains, “By simplifying the power circuitry and reducing component count, chargers and power adapters for everything from laptops to kitchen appliances can become more compact and portable. As millions of electronic devices draw cleaner, sinusoidal current—with high power factor and low THD—from the wall socket, it reduces stress on the power grid. Lastly, cheaper and more reliable power supplies could mean lower upfront costs for consumers, furthering electric vehicles and renewable energy systems.”

Reference
Title of original paper: A Simple Current Sensorless Control Method for Boost PFC
Journal: IEEE Transactions on Consumer Electronics
DOI: 10.1109/TCE.2025.3615203

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SOURCE Chonnam National University