The rise in wireless charging systems is no surprise. These devices provide more convenience and flexibility than their wired counterparts. However, several limiting factors keep wireless chargers from emerging as the industry standard.
Notably, a team of engineers from Incheon National University recently introduced a novel power management system that has the potential to drastically improve wireless charging solutions. The new system provides stable power and reduces interference. Here’s what you need to know.
How Does Wireless Charging Work?
A lot is going on behind the scenes when you lay your phone or a smartwatch on a wireless charging station. These devices accomplish Wireless Power Transfer (WPT) without plugs and through cases using electromagnetic induction.
Electromagnetic induction occurs wirelessly after a wireless transmitting coil located in the charging station comes in the vicinity of a receiver coil. This scenario causes the electrons in the receiver coil to oscillate, creating an electromagnetic field between the two coils that charges your device.
Resonant Circuit
One of the key components of wireless charging systems is the resonant circuit. These devices balance the inductance of the receiver coil to achieve frequency resonance. They also serve a crucial role in boosting power transfer to the unit and lowering circuit impedance.
Resonance Tuning
To control interference and system power, resonance tuning is used. These adjustments will often employ parallel compensated receivers to help modulate the system’s operating frequency. Interestingly, it’s this modulation that creates a mismatch between the modulated and resonant frequencies, resulting in reduced performance.
Problems with Wireless Charging Systems Today
Wireless charging has some serious caveats at this time. For example, it’s much slower than cable alternatives. Additionally, your device needs to be very close for most charging systems to function correctly.
Electromagnetic Interference
The power supply systems and resonant circuits used in today’s wireless charging stations can interfere with resonant circuitry on other devices in the vicinity. This electromagnetic interference reduces the efficiency and performance of wireless charging stations as well.
Low System Efficiency
Traditional wireless charging systems can suffer sudden and unexpected power loss. The main reason for this sudden drop in power is drastic frequency changes in the resonant circuits. This scenario will lead to your devices heating up and charging slowly.
Resonator Tuning Solutions
There have been multiple tuning solutions introduced to the sector since wireless charging entered the market. Notably, all of them require some form of additional hardware. The problem is that these devices add to the complexity, power requirements, and overall size of these devices. Additionally, they are expensive and can require experts to navigate the complex control settings.
Qi Wireless Charging Standard
The most popular wireless charging standard in effect today is the Qi standard. This style of charging station can provide wireless energy to a device around 4 cm away. Its operating frequencies range between 110-205kHz, and it can charge multiple devices at the same time.
Source – Torro
Qi is popular but not efficient. It’s slow and can result in your devices heating up. Your device getting hot can lower battery performance over time. As such, there’s a direct need for more stable and efficient wireless charging solutions. Thankfully, a solution is on the horizon.
Improved Wireless Charging Study
Incheon National University engineers published a study labeled “Resonant Tuning Rectifier for Parallel Compensated Receivers in Wireless Power Transfer“1 in the scientific journal IEEE Transactions on Industrial Electronics this month. The study introduces a new resonant tuning rectifier solution that can provide stable wireless power and could revolutionize the market.
Resonant Tuning Rectifier (RTR)
Resonant tuning rectifiers (RTR) help to correct the resonance mismatch of parallel-compensated RX that occurs during spread-spectrum frequency modulations. To accomplish this task, the unit autonomously adjusts effective capacitance.
This step allows the RTR to tune the resonant frequency by syncing control signals and the system’s current. Once synced, the device can begin compensating for any mismatches between intrinsic resonance and modulation periods.
Specifically, the scientist achieved tuning by synchronizing the rectifier MOSFET’s turn-off with the zero-crossing of the primary current. The system leverages an integrated sensor coil to extract phase information and synchronize its output with the system’s primary current.
Improved Wireless Charging Test
To test their improved wireless charging system, the engineers constructed a 2.2 kW EV charging station prototype. The automobile charging station underwent several testing phases. During these trials, the team gathered data on its performance, efficiency, interference levels, stability, and impact on batteries. The results were impressive.
Improved Wireless Charging Test Results
The new power supply setup improved performance across the board for the charging station. For one, it maintained an operating frequency modulation tuned between 80 — 90 kHz. This frequency allowed the station to provide constant output power.
The engineers noted a 3.5%–8.1% improvement in efficiency when utilizing the upgraded device. The new system achieved added efficiency via its automated systems and its zero voltage switching (ZVS) turn-on and low dv/dt turn-off feature. This feature prevents power loss due to switching.
Improved Wireless Charging Study Benefits
There are a lot of benefits that the wireless charging study introduces to the market. For one, it provides a low-cost alternative to the status quo that improves performance. Additionally, the minimalist design offers more control settings that enable real-time adaptation to use case scenarios.
Stable Power Delivery
The main benefit provided by the upgraded charging solution is reliable and stable power delivery. This benefit is crucial to creating more effective and useful electronics. The upgraded system outperformed its predecessors and produces stable power throughput with minimal energy loss.
No Need for Power Components
Another major benefit of this research is the elimination of additional power components. The new RTR doesn’t require a complex system or added batteries, capacitors, or other bulky power components that would increase the unit’s form factor.
No Need for Control Logic
Along the same line of thought, the upgraded RTR eliminates the need to integrate complex feedback circuitry. There is a lot of energy and space saved, eliminating the need for transmitter-receiver communication systems. The results are smaller and more durable units.
Improved Wireless Charging System Applications
There are near-endless applications for high-performance wireless charging systems. Aside from powering your EV, phone, or watch, these units could provide power to computers, sensors, and an array of devices to simplify life for billions of people. Here are just a few of the potential applications for high-performance wireless charging stations.
Medical
The medical industry could utilize this tech to create more effective monitoring and treatment processes. These devices could provide 24/7 coverage to patients. Already, engineers have looked at wearables, implants, and other critical medical devices that could utilize this tech to improve their capabilities.
Logistics
Another industry that could benefit from improved wireless charging capabilities is the logistics sector. The logistics sector could leverage this study to improve its tracking systems, including IoT devices. These devices could provide around-the-clock monitoring on an entirely new level using wireless charging solutions. In the future, your items will be secure by IoT sensors in warehouses, trucks, and stores.
Improved Wireless Charging System Researchers
The wireless charging study was led by researchers from Incheon National University, Incheon, Korea, with help from a team from The University of Auckland, Auckland. Specifically, Saidul Alam Chowdhury, Seongmin Kim, Sangwon Kim, Inkui Cho, and Duk Ju Ahn contributed to the paper. Now, the team seeks to expand their charging system capabilities and lower its costs, enabling large-scale integration.
Companies Leading in Wireless Charging
The rise of wireless charging options has resulted in several firms becoming dominant players in the market. These companies specialize in R&D and continue to introduce more capable and affordable devices. Here’s one company that is positioned to secure significant ROIs due to any major tech breakthroughs in the industry.
Energous Corporation (WATT +6.84%) entered the market in 2012. It was founded in San Jose, CA, and has since grown to become a leading wireless charging system provider. The company currently offers a wide selection of wireless charging solutions that range from traditional pads to long range warehouse wireless charging solutions.
Energous Corporation’s main product is the WattUp wireless power network. These devices work with IoT units to provide long-range smart charging. It utilizes radio frequency-based charging and is compatible with a massive selection of IoT devices and other electronics.
Energous Corporation (WATT +6.84%)
WATT is seen as a strong addition to your portfolio for several key reasons. For one, the stock has seen recent positive movements. The company’s leading role in the wireless charging sector, plus promised tech updates, is driving this growth.
Currently, WATT has a market cap of $10.791M and a 52-week range of 0.2800 – 2.7000. Those seeking a reputable charging station manufacturer should consider more research into Energous Corp and its offerings.
Latest on Energous Corporation
Wireless Charging will be the Standard Eventually.
There’s little doubt that the moment wireless charging catches up to corded alternatives, it will become the standard. The cost savings, convenience, and flexibility continue to make wireless charging the preferred option for users and manufacturers alike. As such, you may not be too far away from never needing to look for a charging cable or battery again.
Learn about other innovative power solutions HERE.
Study Reference:
1. Chowdhury, S. A., Kim, S., Kim, S., Cho, I., & Ahn, D. (2024). Resonant tuning rectifier for parallel compensated receivers in wireless power transfer. IEEE Transactions on Industrial Electronics, 71(12), 15664–15673. https://doi.org/10.1109/TIE.2024.3390737