#South Korea #Consumer Electronics #Power Factor Correction #Chonnam National University #Jeollanam-do

Groundbreaking Voltage-Loop Control for Enhanced Power Factor Correction

A team of researchers from Chonnam National University in South Korea, led by Professor Sung-Jun Park, has recently unveiled a pioneering control technique aimed at improving power factor correction (PFC) in single-phase power circuits. These circuits, commonly found in devices such as laptop adapters, LED power supplies, and portable chargers, are crucial as they ensure high efficiency and stable direct current (DC) voltage is delivered from the AC source.

The Challenge with Traditional PFC Systems

Traditional boost PFC circuits often rely on current sensors to monitor and maintain optimal performance. However, these sensors can introduce a host of challenges, including noise susceptibility, signal delays, increased complexity of hardware, and potential failures that significantly affect overall system reliability. The researchers have addressed these challenges head-on by proposing a sensorless voltage-loop control method that delivers an unprecedented power factor of nearly 0.9998 while also significantly reducing distortion levels.

A Novel Approach to PFC Control

The newly developed control strategy utilizes a single voltage loop and eliminates the need for current sensors entirely. By deriving an expression for the duty cycle, which comprises both a feedforward component and a control component, the team effectively streamlines the circuit's design. This process takes into account the fundamental equation of inductor voltage and integrates a delay compensation technique, effectively addressing the common issue of phase delay, which often distorts input current.

Professor Park highlighted this innovation, stating, "We specifically identified and solved a common issue in digital control systems where phase delay induces input current distortion. Our built-in compensation technique effectively counters this, contributing to the exceptional power quality our method achieves."

Advantages of Sensorless Control

The shift to a sensorless control approach offers several remarkable benefits. Firstly, it simplifies the design of the circuit by eliminating the need for complex observers and mathematical models, leading to reduced component costs and smaller overall size. This translates not only to lower maintenance requirements but also minimizes wear and tear on components, thus potentially leading to a longer service life. Moreover, the system demonstrates low sensitivity to variations in circuit parameters, enhancing its reliability and making it suitable for mass production without extensive overhauls to existing manufacturing lines.

The technology has been validated with a robust 1.3 kW prototype that achieved near-unity power factors and low total harmonic distortion (THD) of just 2.12% at full load, demonstrating performance that matches or even outperforms traditional sensor-based methods. Professor Park explains, "By simplifying power circuitry and reducing the number of components, we can make chargers and adapters for a broad range of devices—from laptops to kitchen appliances—more compact and portable."

Implications for the Future

The implications of this innovative technology stretch beyond consumer electronics. As millions of devices start to draw a cleaner, sinusoidal current with high power factor and low THD from the power grid, it stands to ease the burden on energy infrastructure. The reduction in energy demand may also lead to lower costs for consumers while promoting wider adoption of electric vehicles and renewable energy systems.

In summary, Chonnam National University's work marks a significant advancement in power electronics. The research not only highlights the potential for improved energy efficiency and reliability in consumer products but also lays the groundwork for future innovations in the field of electrical engineering. The findings, published in the journal IEEE Transactions on Consumer Electronics, represent a crucial step towards more sustainable and efficient power solutions.

Reference

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