Researchers at Chonnam National University have proposed a new way to control power factor correction circuits that could make everyday electronics smaller, cheaper, and more reliable, by removing the need for current sensors.
In a paper published in IEEE Transactions on Consumer Electronics, the team sets out a voltage-loop control method for boost power factor correction, or PFC, a core technology used in laptop chargers, LED power supplies, and fast-charging adapters. The approach relies solely on voltage measurements, rather than the current sensors typically used in such systems, and incorporates a delay-compensation technique to maintain power quality.
Power factor correction circuits sit at the front end of most AC/DC power supplies, shaping the current drawn from the grid to improve efficiency and reduce distortion. While effective, conventional designs depend on current sensors that add cost, introduce noise and delays, and can fail over time. According to the researchers, removing these sensors simplifies the hardware and improves long-term reliability without sacrificing performance.
The work was led by Sung-Jun Park, Professor of Electrical Engineering at Chonnam National University, working with collaborators in South Korea and China. The researchers derived a new duty-cycle equation based on the fundamental inductor voltage relationship, combining a feedforward term with a control term. A built-in delay-compensation mechanism addresses phase delays introduced by digital signal processing, a common source of current distortion in digitally controlled converters.
“In digital control systems, signal-processing delay can distort the input current,” Professor Park said. “By compensating for this delay directly in the control strategy, we can maintain high power quality without additional sensors or complex models.”
The team validated the method on a 1.3 kW prototype, a power level relevant to both consumer and light industrial equipment. Tests showed a near-unity power factor of up to 0.9998 and total harmonic distortion of 2.12% at full load, figures comparable to, or better than, conventional sensor-based approaches. Because the design eliminates current sensors and reduces component count, it also enables a smaller physical footprint and simpler circuitry.
The researchers argue that the method’s low sensitivity to parameter variations makes it well suited to mass production. It can be implemented on standard digital signal processors and integrated into existing manufacturing lines without major redesign, potentially lowering barriers for adoption by power supply manufacturers.
Early beneficiaries are likely to include laptop and notebook adapters, smartphone fast chargers, LED televisions and monitor power supplies, server power units, and power tools, all of which operate in the medium-power range where efficiency and size are critical. Over the longer term, the team suggests that widespread use could reduce electronic waste, lower costs, and ease strain on electricity grids by improving the quality of current drawn from millions of devices.
“By simplifying the power circuitry and reducing component count, chargers and adapters can become more compact and portable,” Professor Park said. “If large numbers of devices draw cleaner, more sinusoidal current from the socket, it reduces stress on the grid and supports wider electrification.”
The research adds to growing efforts to make the hidden infrastructure inside consumer electronics not only cheaper and smaller, but also more efficient at a system-wide level, contributing to a more sustainable energy ecosystem.
