The Evolution of Contactless Power: Advancing Efficiency with 140 kHz Systems
Guest blog by MHI Member Vahle
Over the past 50 years, electromagnetic field (EMF) technology has transformed how industrial systems receive energy. What began as a simple way to transmit power without physical contact has evolved into a high-efficiency, data-driven solution for continuous operation. Modern 140 kHz contactless power systems mark a major milestone in this evolution, combining advanced power electronics, digital diagnostics and hybrid flexibility to meet the increasing industrial demands of automated manufacturing.
From 10 kHz to 140 kHz: A Leap in Power Technology
Earlier generations of contactless power operated around 10 kHz, which required large components and delivered limited efficiency. Today’s 140 kHz systems, enabled by advanced microcontroller (MCU) technology, achieve power transfer efficiencies exceeding 94 percent while simultaneously reducing system size and allowing for significant cost savings. Operating at a higher frequency enables more energy to be transferred at the same current level. This advantage allows designers to reduce current requirements, leading to lighter components, smaller footprints, and improved overall energy efficiency. This step forward in engineering represents one of the most substantial advances in the history of inductive power transfer.
How Inductive Power Transfer Works
At the core of the system is electromagnetic induction. A primary coil embedded in the floor or track generates an alternating magnetic field at 140 kHz, which is received by a secondary coil, or “pickup,” mounted on the moving vehicle. The pickup converts this energy into DC power, eliminating mechanical contact and preventing wear or contamination. Continuous power can be supplied with or without an onboard battery, ensuring uninterrupted operation even in demanding production environments.
High Frequency, High Efficiency
The shift to 140 kHz brings measurable gains in energy performance. Not only do these systems generate minimal heat, but they also maintain consistent power quality even under load variations. The design’s large vertical and lateral tolerances allow vehicles to move freely without power interruption. With fewer power bus drops and lower voltage fluctuations, manufacturers benefit from reliable performance across complex or reconfigurable layouts.
Hybrid Operation for Greater Flexibility
Today’s innovative contactless power systems support hybrid operation, combining continuous inductive power with battery storage. This design enables automated mobile robots (AMRs) and automated guided vehicles (AGVs) to remain in motion without pausing for charging. Continuous charging extends battery life, reduces the total number of vehicles required and eliminates charging stops that slow production. Hybrid flexibility also allows manufacturers to adjust lines or product flow rates without reengineering power infrastructure.
Smart Monitoring and Diagnostic Capability
Built-in diagnostic modules track key system data such as current, voltage and phase angle in real time. Through interfaces like PROFINET IO and EtherNet/IP, operators gain full visibility into performance and fault conditions. Event recording and SD-card storage simplify maintenance and support predictive service planning, turning the power system into an active data source that enhances manufacturing intelligence.
Compact and Adaptable for Modern Manufacturing
The compact modular design allows flexible installation in both new and existing facilities. The separation of pickup and regulator makes integration into vehicles straightforward, while coaxial connections minimize electromagnetic interference. This adaptability supports quick line reprocessing when product types or job-per-hour rates change, offering manufacturers greater agility without compromising uptime.
Operational and Economic Impact
Continuous contactless power eliminates the inefficiencies of stop-and-charge systems. These systems allow for the use of fewer AMRs, longer battery life durations, improved production flow and overall increased productivity. Many facilities see a return on investment in under a year, driven by reduced battery maintenance and increased equipment availability. With the ability to adapt to ever-evolving manufacturing needs, 140 kHz contactless power technology represents one of the most impactful advancements in modern intralogistics.
