EMF and EMC Testing Strategy for High-Power Wireless Power Transfer (WPT)

1. Executive Summary

As high-power Wireless Power Transfer (WPT) expands into applications including electric vehicles, AGVs and AMRs, industrial robots, and automation equipment, it is evolving into a technology that requires verification of not only power transfer performance but also Electromagnetic Compatibility (EMC), human exposure to Electromagnetic Fields (EMF), and system safety. In particular, as transfer power increases and operating environments become more diverse, the electromagnetic environment may vary depending on the distance and alignment between the transmitter and receiver, output power and load conditions, and measurement locations. A repeatable testing framework that reflects actual operating conditions is therefore important. Research on high-power WPT has also involved EMF assessments that consider system positioning and alignment conditions, as well as EMI measurements using an anechoic chamber, demonstrating the need for an approach that considers the entire test environment.

Accordingly, high-power WPT testing infrastructure needs to be developed beyond the performance of individual measurement instruments, by integrating the test space and shielding and absorption environment, a positioner that controls the locations of the DUT and the transmitter and receiver, EMF and EMC measurement systems, automated test control, and data analysis and reporting systems. Since EMC and EMF are distinct areas with different assessment objectives and applicable criteria, they should be configured separately according to the test objectives. However, using a shared test environment and control and data platform enables consistent reproduction of various operating conditions and ensures the repeatability, reproducibility, and traceability of test results. Depending on the applicable standards and system configuration, this foundation can be extended to safety verification, including Foreign Object Detection (FOD), Living Object Detection (LOD), and protective functions.

Wireless Power Transfer (WPT) is expanding its application scope, primarily from electric vehicles to various mobile platforms and automation systems, based on its ability to transfer power without a physical power connection. Even within EV applications alone, power levels, operating frequencies, distances between the transmitter and receiver, and system architectures vary considerably depending on the application. A 2023 WPT review presents various systems for passenger cars and buses, ranging from several kilowatts to tens of kilowatts, and shows that each system uses different frequencies and power transfer distances. This is an important reason why WPT testing is difficult to define using a single fixed set of conditions.

Power level is not the only factor that makes test conditions more complex. The electromagnetic fields generated by a WPT system are affected not only by the operating frequency, pad structure, and coupler design but also by actual operating conditions, such as the alignment between the transmitter and receiver. A study applying a 25 kW IPT system to an actual electric shuttle confirmed that increased misalignment between the transmitter and receiver can increase the leakage field around the system. It proposed first defining the worst operating condition that produces the highest EMF, considering various alignment combinations involving the X, Y, and Z directions and pitch, roll, and yaw, and then conducting the tests. The actual measurements also compared electric and magnetic fields around the vehicle at multiple alignment positions, confirming that changes in transmitter and receiver positions can serve as direct test variables in stray field assessment.

As system power increases, the test environment also becomes more important from an EMC perspective. A study of a 100 kW WPT system for electric buses developed a system capable of transferring a maximum power of approximately 115 kW and measured the radiated magnetic fields generated in the 85 kHz band in a 10 m anechoic chamber. The study evaluated both the fundamental frequency component of WPT and harmonic emissions, and verified the effectiveness of EMI reduction techniques, such as opposite-phase transfer, spread spectrum, and low-pass filtering, in an actual test environment. This demonstrates that high-power WPT testing is a verification process that must consider power conditions, frequency components, system configuration, and the test environment together, rather than simply checking a single measurement at rated output.

In addition, the actual operating environment of a WPT system requires distinguishing between areas accessible to people and those that are not, and setting different test conditions for each area. The 25 kW IPT study divided the space between the transmitter and receiver pads, the vehicle underbody, the area around the vehicle, and the vehicle interior into separate EMF test zones, and established separate measurement points around and inside the vehicle where people have direct access. In particular, measurement locations around the vehicle were selected where the highest fields were expected, and the FFT distributions and maximum RMS values of the electric and magnetic fields were evaluated.

The complexity of WPT testing therefore does not arise simply from an increase in the number of industries in which it is applied. The central point is that power levels, operating frequencies, transmitter and receiver structures and distances, misalignment, load conditions, measurement locations, and accessible areas differ from system to system, and EMF and EMC characteristics may vary according to these variables. High-power WPT testing infrastructure should therefore be designed to repeatedly establish various position, power, and alignment conditions and compare them using the same test procedure, rather than reproducing only one specific operating condition.

The most important change in the WPT test environment is not the increase in the number of test items, but the substantial increase in operating variables that affect test results. Verifying the reliability of high-power WPT systems requires repeatable reproduction of not only power and frequency but also transmitter and receiver positions and alignment, measurement points, and actual access conditions. The next stage of testing infrastructure therefore needs to be designed around how accurately and consistently it can implement various test conditions, rather than the performance of individual measurement instruments.

3. Key Testing Challenges

EMF, EMC, and Safety Must Be Approached as Distinct Verification Areas

Verification of high-power WPT systems requires distinguishing the objectives and assessment targets of EMC, EMF, and system safety, rather than combining them into a single test item. When transferring high power through power electronic circuits and transmitter and receiver couplers, WPT systems can generate electromagnetic emissions at both the fundamental operating frequency and its harmonics. EMC testing assesses the impact of these emissions on the surrounding electromagnetic environment and verifies the system’s electromagnetic compatibility according to the applicable test requirements. A study of a 100 kW WPT system for electric buses measured radiated magnetic fields in the 85 kHz band and at harmonic frequencies in a 10 m anechoic chamber using a system with a maximum transfer power of approximately 115 kW, and verified methods for reducing radiation levels by applying opposite-phase transfer, spread spectrum, and low-pass filtering.

EMF assessment evaluates the electric and magnetic fields to which people may be exposed around a WPT system, rather than electromagnetic compatibility between equipment. The EMF generated by an IPT system can vary depending not only on the operating frequency, pad structure, and coupler design but also on operating conditions, such as the alignment between the transmitter and receiver. A measurement study of a 25 kW IPT system proposed first identifying the worst operating condition that produces high EMF by combining X, Y, and Z displacements with pitch, roll, and yaw, and then conducting the tests, considering that increased misalignment can increase leakage fields around the system. The actual measurements also showed that measured EMF varied under different misalignment conditions.

Measurement location is also an important variable in EMF assessment. The 25 kW IPT study divided the test areas into the vehicle underbody where the transmitter and receiver pads are located, the area around the vehicle, and the vehicle interior, and established separate measurement points for each area. For testing inside the vehicle, a coordinate system was also established relative to the receiver center, and magnetic field distributions were examined by changing the probe height and measurement positions in the X and Y directions. A decrease in magnetic field strength with increasing measurement height was also observed, demonstrating that measurement results can vary depending on probe position and distance, even within the same system. Therefore, EMF testing requires not only the selection of appropriate measurement instruments but also position control that can repeatedly reproduce the probe position, distance from the DUT, and alignment between the transmitter and receiver.

FOD and LOD Require Separate Safety Verification Scenarios

Foreign Object Detection (FOD), which detects metallic foreign objects, and Living Object Detection (LOD), which detects living objects, are WPT system safety functions distinct from EMC or EMF measurements themselves. In particular, strong electromagnetic fields are formed between the transmitter and receiver pads, making it important to manage situations in which objects approach this area. The approach in SAE J2954 cited by the 25 kW IPT study presents measures for ensuring safety in this area, including reducing electromagnetic field levels, active and passive access control, and automatically detecting metallic and living objects and shutting down the system before they enter the area.

Therefore, FOD and LOD testing requires scenarios that verify whether detection functions operate correctly according to object position and approach conditions, and whether the system subsequently transitions to the required protective operation, rather than simply checking whether a sensor detects an object. Specific test objects and positions, detection conditions, and acceptance criteria must be defined separately according to the applicable standards and WPT system configuration. The currently available sources support the need for FOD and LOD and the safety concept of automatic detection and shutdown, but do not provide detailed test procedures or a single acceptance criterion applicable to all high-power WPT systems.

Repeatability and Reproducibility Determine the Reliability of Test Results

Another key challenge in high-power WPT testing is repeatedly implementing identical test conditions while controlling multiple variables. In the EMF measurement study, tests were conducted by aligning the probe coordinates with the measurement points and defining the measurement directions relative to the transmitter and receiver pads. Measurements inside the vehicle were also repeated at different heights and positions, while touch current testing involved multiple enable/disable operations with the IPT system operating at full power. These test configurations demonstrate that WPT assessment requires not only the measurement values themselves but also a process for clearly defining and reproducing test conditions.

Therefore, managing the accuracy of measurement equipment alone is insufficient to improve the reliability of high-power WPT testing. The positions of the DUT, transmitter, and receiver, distances and offsets, probe positions, power, and system operating states must be managed together as test conditions, and the same conditions must be implemented repeatedly. This is also why the positioner, DUT fixation system, measurement equipment, test control, and data management systems need to be connected as a single test process rather than treated as individual pieces of equipment.

The main challenge in high-power WPT testing is to distinguish the different verification objectives of EMF, EMC, and safety while consistently managing the position, alignment, power, and operating conditions that affect each test. In particular, when considering EMF variations caused by misalignment and measurement position, EMI during high-power operation, and protective functions such as FOD and LOD, a test configuration centered on a single measurement instrument makes it difficult to systematically reproduce various operating conditions. The next step therefore requires examining how test space, positioning, measurement, automation, and data can be configured as a single infrastructure to address these testing challenges in an actual test environment.

The core of high-power WPT testing infrastructure is not to perform multiple tests in the same way within a single chamber, but to connect test environments that accommodate different test objectives and conditions through a shared control, measurement, and data platform.

The Test Environment Must Be Designed According to Power Levels and DUT Characteristics

The test space must be designed based on the WPT system’s power level, DUT size, required measurement distance, and test objectives. EMC measurements require a test environment that reduces the influence of the external electromagnetic environment and enables stable assessment of radiation characteristics. RF shielding and electromagnetic absorption structures can be applied as needed. A study of a 100 kW WPT system measured the radiated magnetic fields of an electric bus system with a maximum transfer power of approximately 115 kW in a 10 m anechoic chamber. This demonstrates that EMC testing of high-power WPT systems may require a test space that accommodates the DUT size, measurement distance, and power system.

It cannot be generalized that all WPT tests require the same type of fully anechoic chamber. The test environment should be designed to appropriately manage external electromagnetic fields, reflections and scattering, and safety zones according to the applicable test objectives and measurement methods. Therefore, rather than deciding on the chamber type first, it is appropriate to first define the intended EMF and EMC tests, DUT size and power level, and required measurement distances and arrangement conditions, and then determine the test space and shielding and absorption environment accordingly.

Positioning Is a Key Element in Reproducing WPT Operating Conditions

In WPT systems, the relative positions of the transmitter and receiver can directly affect electromagnetic field characteristics, making the positioning structure an important component of the testing infrastructure. The 25 kW IPT system study selected the worst operating condition by combining displacements in the X, Y, and Z directions with pitch, roll, and yaw, considering that misalignment between the transmitter and receiver can affect leakage EMF. Probe positioning was also managed by aligning its XYZ reference point with the actual measurement point.

The testing infrastructure should therefore be configured to securely fix the relative positions of the DUT and the transmitter and receiver pads, and to repeatedly reproduce distance, horizontal and vertical offsets, and orientation where necessary. The role of the positioner and DUT fixation system is not simply to move equipment, but to improve the comparability and reproducibility of test results by repeatedly implementing identical operating conditions.

Measurement Systems Should Be Configured in Modules According to Test Objectives

For measurement, combining the equipment required for each test objective is more appropriate than using a single instrument to perform all tests. EMC testing may require a receiver and associated measurement systems for measuring radiated and conducted emissions, while EMF assessment requires probes and a field analyzer capable of measuring electric and magnetic fields. When power transfer performance is assessed alongside these tests, a power analyzer can be integrated to measure input and output voltages and currents, power, and efficiency.

The 25 kW IPT study used a low-frequency isotropic probe capable of simultaneous three-axis measurement, connected it to a PC through a fiber-optic cable, and used dedicated software to configure the probe and collect and store data. This demonstrates that instruments and software in WPT testing can operate as a single measurement chain connecting measurement condition settings with data recording, rather than existing independently.

Automation Should Be Approached as a Structure Connecting Test Conditions and Measurement Data

High-power WPT testing may require repeated measurements while sequentially changing multiple variables, such as power, load, alignment, and probe position. It is therefore efficient to configure the automation system to connect the positioner, DUT, WPT system, and measurement equipment, set conditions according to predefined test sequences, and automatically record measurement results.

The currently available WPT experimental papers directly demonstrate configuration, data collection, and storage through probes and PC software, as well as the need for repeated measurements under actual test conditions. However, they do not present a specific reference architecture integrating the positioner, measurement instruments, and DUT into a single commercial automation platform. It is therefore accurate to present the Automation–Data–Reporting structure in this white paper as a strategy for developing testing infrastructure to consistently manage the various test variables identified above, rather than as a requirement of a specific standard or a direct test configuration from an existing paper.

An automated structure enables each measured value to be stored together with the DUT ID, power, load, transmitter and receiver positions, probe position, and test mode, allowing results to be compared across conditions. Subsequently linking analysis results and assessment information within the same data structure enables their use in repeated testing, comparisons before and after design changes, and test history management. Configuring the final report to automatically connect test conditions and results, rather than manually transferring raw data, can also improve operational efficiency and data traceability.

Overall Flow of the Reference Test Architecture

High-power WPT testing infrastructure can be configured as the following continuous flow.

Test Environment

• Positioning
• EMF, EMC & Performance Measurement
• Automation & Control
• Data Acquisition & Analysis
• Result Comparison & Validation
• Reporting

In this structure, the test environment provides the physical foundation for measurement, and the positioning system repeatedly reproduces actual operating conditions. The measurement systems collect data for different objectives, including EMF, EMC, and performance, while the automation system connects test conditions with measurement equipment. Subsequently, managing test conditions and results together during data analysis and reporting ensures repeatability, reproducibility, and traceability throughout the entire testing process.

The reference test architecture for high-power WPT is not a test system built around a single measurement instrument or chamber. Its central principle is to design the test environment, positioning of the DUT and the transmitter and receiver, EMF and EMC measurements, power and safety verification, test control, data management, and reporting as one continuous testing framework. This structure allows the required measurement equipment and test scenarios to be changed according to different WPT systems and test objectives while maintaining a shared test operation framework and data management structure.

The first step in establishing a high-power WPT test laboratory is to clearly define which tests will be performed. The target industries, WPT system power range, DUT size and structure, operating frequency, distance between the transmitter and receiver, allowable alignment range, and required EMF, EMC, and safety verification items must be identified first. In the 25 kW IPT demonstration study, EMF and touch current tests were configured after first defining conditions such as the system’s rated power, operating frequency, pad structure, and distance between the transmitter and receiver. For EMF testing, measurement areas and test points were also established separately around the actual vehicle, inside the vehicle, and around the power conversion modules. Establishing a test laboratory should therefore begin by defining the test scope and DUT operating conditions rather than selecting an equipment list.

Once the test scope has been defined, the space and facility conditions needed to reproduce it must be designed. This requires considering not only the physical space for installing the DUT, WPT transmitter and receiver systems, power supply equipment, and measurement instruments, but also measurement distances, positioner travel ranges, safety zones, and access routes. Since high-power WPT testing may involve operating the system at full power, the concepts of a safety perimeter and interlocks are also important for managing access by test personnel and unauthorized persons. In the 25 kW IPT study, a safety perimeter was first established around the vehicle during full-power operation, and EMF was checked at multiple measurement points before defining the test boundary within which work could be performed.

When EMC testing is performed, shielding and absorption environments that manage external electromagnetic fields and reflection effects must also be considered according to the test objectives. A 10 m anechoic chamber was used for radiated magnetic field testing of a 100 kW WPT system for electric buses. Although this example does not need to be applied identically to every WPT test laboratory, it demonstrates that test space design must come first for high-power systems, accounting for DUT size, measurement distance, and the power feed arrangement. Chamber design should therefore consider actual operating conditions, including high-power supply feeds, cable routing, DUT installation and removal, cooling, and safety facilities, alongside RF shielding and absorbers.

Positioning Is Designed Around Test Scenarios

The positioning system must be considered alongside the test space. Since WPT EMF characteristics can vary with the relative positions of the transmitter and receiver, the positioner’s travel range and precision must enable reproduction of the DUT’s actual misalignment conditions. The 25 kW IPT study presented displacements in the X, Y, and Z directions and pitch, roll, and yaw as variables for identifying the worst operating condition. The actual tests also compared EMF under multiple X and Y misalignment conditions and at the maximum air gap.

The positioning system should therefore be designed after defining the offset and orientation ranges required for actual testing, rather than being selected solely on nominal precision. Fixtures that reproduce identical transmitter and receiver positions when the same DUT is removed and reinstalled or tested repeatedly are also important. The EMF probe must likewise be positioned repeatedly at the specified locations and heights with accuracy. In the study, the probe’s XYZ reference point was aligned with the measurement point, and repeated measurements were performed at multiple positions and heights.

Measurement Systems Are Configured as Measurement Chains for Each Test Objective

Measurement systems must be configured to meet the respective requirements of EMF, EMC, performance, and safety testing. EMF testing requires probes and analyzers capable of measuring electric and magnetic fields, while EMC testing requires receivers and associated measurement equipment suited to the intended radiated and conducted emission tests. If power transfer performance is also assessed, a power measurement system can be added to record input and output power, voltage, current, and load conditions.

The important consideration in equipment selection is to configure a measurement chain suited to the overall test conditions, rather than prioritizing the highest specifications of individual instruments. The 25 kW IPT test used a three-axis isotropic field probe covering the 5 Hz–100 kHz band, connected the probe to a PC through optical fiber, and performed configuration, data collection, and storage using dedicated software. This demonstrates the need to manage measurement instruments, data acquisition devices, and software as a single measurement system.

Automation Is Built Around Repeated Testing and Data Traceability

High-power WPT testing may involve repeating multiple tests on a single DUT while changing power, load, transmitter and receiver positions, probe position, and operating state. Setting these conditions manually can increase test time and introduce differences in settings between test personnel. It is therefore efficient to connect the positioner, DUT, WPT power system, and measurement equipment to a shared test controller and configure them to follow a predefined sequence: condition setup → stabilization → measurement → storage → transition to the next condition.

The purpose of automation extends beyond moving equipment remotely. A structure is needed to record each measured value together with the power and load, Tx/Rx alignment, and probe position under which it was generated. For example, data can be linked as follows.

Applying this structure makes it easier to compare results from retesting the same DUT or from before and after design changes, and enables tracing the test conditions under which a particular measured value was obtained. The currently available 25 kW IPT study also compares results by distinguishing measurement points, alignment, probe height, and full-power conditions, confirming the need to manage conditions and measurement results together in WPT testing.

Calibration and System Verification Are Managed Separately

Once the test laboratory has been established, the fact that equipment has been installed does not by itself guarantee the reliability of measurement results. The calibration status of individual instruments, such as probes, EMC receivers, and power analyzers, must be checked, and the positioning system’s positional accuracy and repeatability, sensor condition, cables and fixtures, and test software settings must be managed continuously.

It is important to distinguish calibration from verification of overall system performance. Calibration is the process of determining an individual instrument’s measurement characteristics relative to reference values, while system verification can be viewed as the process of confirming whether the required test conditions are reliably reproduced in the actual test environment with the instruments, positioning system, fixtures, and software connected. The testing infrastructure architecture in the white paper “Power Density Measurement Technologies for Assessing Human Exposure to Electromagnetic Fields in the 5G and 6G Era” also applied the principle that individual probe calibration alone does not automatically ensure the reliability of overall results, and that positioning repeatability, DUT alignment, the test environment, and software must all be managed as part of the complete measurement chain.

The same implementation principle can be applied to high-power WPT. However, specific procedures such as the Relative System Check, Absolute System Check, and System Validation in IEC/IEEE 63195-1 are requirements for high-frequency power density measurements and must not be directly applied as mandatory procedures for all WPT testing. For WPT testing, the necessary calibration and verification procedures should be defined separately according to the actual applicable standards and measurement methods.

Operation and Maintenance Are Managed Throughout the Testing Infrastructure Lifecycle

The performance of testing infrastructure does not remain fixed at the time of implementation. With long-term use, instrument calibration status may change, as may the positioner’s mechanical alignment, fixture repeatability, sensor condition, cable connections, test environment, and software version. These changes must therefore be managed alongside the test history to maintain the comparability of results over the long term.

In particular, high-power WPT test laboratories are likely to need to accommodate new power ratings, DUT configurations, and additional test items, making it beneficial to consider scalability from the initial design stage. Modular interfaces that allow positioners and measurement equipment to be replaced or new sensors and test modules to be added, together with software and data structures that are not excessively dependent on specific equipment, make it easier to respond to future changes in testing requirements.

As the application of high-power Wireless Power Transfer (WPT) expands, the scope of testing is also extending beyond verification of power transfer performance to verification of EMF, EMC, system safety, and actual operating states. A demonstration study of a 25 kW IPT system evaluated transmitter and receiver misalignment, measurement locations around and inside the vehicle, and touch current under different conditions, while a study of a 100 kW WPT system for electric buses measured radiated magnetic fields at the fundamental operating frequency and its harmonics in a 10 m anechoic chamber. These studies demonstrate that the reliability of high-power WPT is difficult to determine from a single measured value or test item, and that actual test scenarios incorporating system power, position, and operating conditions are required.

EMF and EMC are also distinct assessment areas. ICNIRP 2020 provides a framework for limiting human exposure to RF electromagnetic fields in the 100 kHz–300 GHz range, while explicitly identifying interference caused by electronic devices to other equipment—that is, EMC—as outside the scope of the guidelines. IEEE C95.1-2019 also specifies safety levels for human exposure in the 0 Hz–300 GHz range. WPT test laboratories must therefore configure EMF tests that assess human exposure, EMC tests that assess compatibility with the surrounding electromagnetic environment, and system safety tests such as FOD, LOD, and protective operation according to their respective objectives and applicable criteria.

The performance of individual measurement instruments alone is insufficient to operate these tests reliably. The test chamber and shielding and absorption environment, positioners and fixtures that reproduce the positional relationships between the DUT, transmitter, and receiver, EMF and EMC measurement systems, power and safety measurement devices, automated test control, and data analysis environment must be interconnected. In WPT testing in particular, relative transmitter and receiver positions and measurement points can affect results, making it important to repeatedly implement identical distances, offsets, power, and load conditions and record these conditions together with measurement data. The 25 kW IPT study also defined misalignment as a test variable, clearly specified measurement locations, and compared results, confirming the need for such repeatability and reproducibility.

Ultimately, competitiveness in high-power WPT testing is determined less by the number of individual test instruments available than by the ability to operate different tests within a consistent and traceable test environment. Connecting Test Environment–Positioning–Measurement–Automation–Data–Reporting as a single test platform enables more flexible responses to repeated testing, comparisons of design changes, test history management, and future DUTs and testing requirements.

As the application scope and transfer power of high-power WPT expand, the ability to design the entire test environment as a single system will extend beyond providing a foundation for verifying product compliance and safety. It will become essential infrastructure that determines testing efficiency, repeatability, reproducibility, and data reliability for manufacturers and testing organizations.

7. Appendix

7.1 Key International Standards and Guidelines

The following key international standards and guidelines can serve as references for the EMF, EMC, and safety assessment of high-power Wireless Power Transfer (WPT) discussed in this white paper.

EMF assessment of high-power WPT requires distinguishing the applicable human exposure guidelines according to the system’s operating frequency. ICNIRP Guidelines 2010 provides a framework for limiting human exposure to time-varying electric and magnetic fields in the 1 Hz–100 kHz range, making it a key reference when assessing the WPT systems operating in the 20 kHz and 85 kHz bands discussed in this white paper. The 25 kW IPT demonstration study also assessed the EMF of a system operating at approximately 20 kHz by comparing it with the general public exposure reference levels in ICNIRP 2010.

ICNIRP Guidelines 2020 addresses RF electromagnetic field exposure in the 100 kHz–300 GHz range and distinguishes between basic restrictions and reference levels. It is therefore important to distinguish the applicability of ICNIRP 2010 and 2020 according to the WPT system’s frequency range, rather than treating them as a single set of criteria. In particular, ICNIRP 2020 replaces the portions of ICNIRP 2010 covering the 100 kHz–10 MHz range, so the applicable frequencies and assessment items must be checked in the boundary region between the two guidelines.

IEEE Std C95.1-2019 specifies safety levels for human exposure to electric, magnetic, and electromagnetic fields in the 0 Hz–300 GHz range. It can therefore be used as a reference framework for reviewing human exposure safety criteria across a broad frequency range, rather than addressing only a specific WPT operating frequency.

For EV WPT systems, SAE J2954 and the IEC 61980 series serve as important reference frameworks for testing and design. The 25 kW IPT demonstration study configured EMF and touch current tests based on SAE J2954, IEC 61980, IEC 60990, and other standards, and evaluated test zones around and inside the vehicle, misalignment, and safety perimeters.

The scope of standards and detailed test procedures may vary depending on WPT system power, operating frequency, the applicable vehicle or industry category, and test objectives. When establishing an actual test laboratory, the target system’s operating frequency and applicable regulatory requirements must therefore be defined first, followed by verification of the latest editions and specific clauses of the appropriate human exposure criteria and product and test standards.

7.2 Key References

This white paper used the following research materials as key references to explain EMF and EMC test conditions for high-power WPT systems, electromagnetic field variations caused by misalignment, radiation characteristics of high-power systems, touch current, and WPT system configuration and safety.

[1] Experimental Study of EMF and Touch Current in a 25 kW IPT System

A. A. S. Mohamed, A. Meintz, P. Schrafel, and A. Calabro, “Testing and Assessment of EMFs and Touch Currents From 25-kW IPT System for Medium-Duty EVs,” IEEE Transactions on Vehicular Technology, Vol. 68, No. 8, pp. 7477–7487, 2019. DOI: 10.1109/TVT.2019.2920827.

This study measured EMF and touch current around and inside the vehicle and around the power supply system of a commercial 25 kW IPT system installed in an actual electric shuttle. In particular, considering that misalignment between the transmitter and receiver pads can affect leakage fields, the study explored the worst operating condition under X, Y, and Z displacement and pitch, roll, and yaw conditions, and established measurement points and a safety perimeter.

This white paper used the study to explain that high-power WPT testing must manage not only rated power but also Tx/Rx alignment, probe position, measurement distance, and actual operating conditions as test variables.

[2] Study of EMI Reduction and Radiation Measurements in a 100 kW WPT System

H. Uno, K. Ogawa, T. Shijo, Y. Kanekiyo, K. Ogura, S. Obayashi, and M. Ishida, “EMI Reduction Techniques from 100 kW Wireless Charging Systems for Heavy-Duty Vehicles,” Proceedings of ISAP2020, Osaka, Japan, pp. 729–730, 2021.

This study developed a WPT system for electric buses that transfers a maximum power of approximately 115 kW and measured radiated magnetic field characteristics in a 10 m anechoic chamber, focusing on the 85 kHz band. Opposite-phase transfer, spread spectrum, and low-pass filtering were applied to reduce fundamental frequency and harmonic radiation, and their effectiveness was verified through actual measurements.

This white paper used the study as evidence that EMC testing of high-power WPT must consider DUT size, power level, measurement distance, and a controlled test environment together.

[3] Systematic Review of EV Wireless Charging Technology

P. Vishnuram, S. P., R. Narayanamoorthi, K. Vijayakumar, and B. Nastasi, “Wireless Chargers for Electric Vehicle: A Systematic Review on Converter Topologies, Environmental Assessment, and Review Policy,” Energies, Vol. 16, Article 1731, 2023. DOI: 10.3390/en16041731.

This review comprehensively summarizes compensation topologies, power converters, control techniques, static and dynamic wireless charging, environmental impacts, and safety issues in EV WPT systems. In particular, it shows that WPT systems consist of multiple subsystems, including a power converter, compensation network, charging coupler, control unit, and detection system.

This white paper used the review as a reference to explain the technical background and application scope of high-power WPT, system configuration, and the reasons testing requirements are becoming more complex.

Principles for Using References

This white paper distinguished between the roles of international standards and research papers. ICNIRP, IEEE, SAE, and IEC documents were given priority in explaining normative criteria, such as human exposure limits, testing frameworks, and safety requirements, while the research papers above were used as empirical evidence showing how test conditions and measurement methods are implemented in actual WPT systems.

Accordingly, specific limits and mandatory test procedures must be verified against the relevant standards and guidelines. The power levels, measurement distances, misalignment conditions, or test equipment configurations used in the papers must not be interpreted as requirements that apply identically to all WPT systems.

7.3 Key Terms

Misalignment and repeatability are particularly important concepts in high-power WPT testing. The 25 kW IPT test explored operating conditions that produced high EMF by considering X, Y, and Z displacements and pitch, roll, and yaw conditions, and performed repeated measurements with clearly defined measurement locations and probe positions.

7.4 WPT Testing Infrastructure Implementation Checklist

The following items should be checked in advance when establishing an actual high-power WPT test laboratory.

The central purpose of this checklist is to confirm whether the entire actual test sequence can be implemented repeatedly, rather than reviewing chambers or measurement equipment individually.

7.5 Main Components of Test Result Reliability

The reliability of high-power WPT testing is not determined solely by probe accuracy or EMC receiver performance. In an actual measurement chain, measurement, positioning, the test environment, DUT operating conditions, and data processing can all affect test results simultaneously.

Measurement-related factors include the calibration status of the EMF probe or EMC receiver, frequency response, linearity, dynamic range, and long-term instrument drift.

Positioning-related factors include Tx/Rx distance, X, Y, and Z misalignment, DUT orientation, probe position and height, and fixture remounting errors. The 25 kW IPT demonstration study also tested multiple alignment conditions on the premise that misalignment can cause variations in leakage fields.

Test environment factors may include chamber reflections, the ambient electromagnetic environment, the influence of the DUT holder and surrounding metal structures, and cable routing. The 100 kW WPT EMI study measured radiated magnetic fields in a 10 m anechoic chamber to examine fundamental and harmonic radiation characteristics in a controlled test environment.

DUT operation factors include output power, load conditions, operating frequency, control mode, Tx/Rx alignment, and output drift during repeated testing. Ensuring the reliability of test results therefore requires managing not only the calibration of individual instruments but also how these variables are defined and reproduced throughout the entire test sequence.

7.6 Reference Test Infrastructure Summary

The reference test infrastructure proposed in this white paper can be summarized as the following flow.

The central principle of this structure is to connect Test Environment–Positioning–Measurement–Automation–Data–Reporting as a single test system, rather than treating each element as independent equipment. In high-power WPT in particular, measurement results can vary according to transmitter and receiver positions and operating conditions. Automation and data management must therefore be approached as components of testing infrastructure for ensuring repeatability and traceability, rather than merely as convenience functions.

7.7 Final Review Questions Before Implementation

The following questions must be answered clearly before proceeding with detailed laboratory design and equipment procurement.

Resolving these questions during the implementation stage can transform the establishment of a WPT test laboratory from a simple measurement equipment purchasing project into a project to build High-Power WPT EMF, EMC & Safety Testing Infrastructure that can be used over the long term.