TUNKIA’s Electromagnetic Measurement Solution for NEV Three-Electric Systems and EV Charger Testing

Introduction

In 2025, China's new energy vehicle industry has entered a new phase of quality upgrading, imposing higher demands on electromagnetic metrology and testing technologies. Against this backdrop, this paper focuses on the engineering applications of electromagnetic measurement technologies in the new energy sector, with an emphasis on analyzing the testing requirements, technical challenges, and solutions for electric vehicle "three-electric systems" (battery, motor, and electronic control) and charging facilities, thereby providing metrological support for high-quality industrial development.

Part 1 Analysis of Measurement Requirements in the New Energy Vehicle Industry

For electric vehicles, the primary focus is often on the "three-electric systems": the motor, battery, and electronic control. In related production and R&D processes, various measurement requirements exist, including magnetic material testing, battery performance testing, and sensor calibration.

Furthermore, a typical scenario in the new energy vehicle sector is the power supply of electric vehicles by EV chargers. Different measurement requirements arise in both EV charger and electric vehicle applications. EV chargers themselves are among the mandatory managed measuring instruments. Internally, they typically use shunts and DC electrical energy meters for charging energy measurement. Additionally, DC shunts are widely used in automotive BMS (Battery Management System).

To address the metrological testing requirements of various instruments in the new energy vehicle sector, TUNKIA has developed a series of precision instruments with different accuracy levels based on the latest "IPMA" (Integrated Precision Measurement Architecture). These instruments provide comprehensive solutions for various testing needs. The following sections will analyze specific testing requirements and solutions in each field, with a focus on TUNKIA's solutions.

Part 2 Detailed Analysis of Subdivision Applications

2.1 TUNKIA Magnetic Material Testing Solution

In new energy vehicles, efficient and reliable power and control systems rely on the support of various magnetic materials. Whether it is the electrical steel used in the stator and rotor of the drive motor system, the permanent magnets such as NdFeB and SmCo used in the motor rotor, or the various soft magnetic materials such as amorphous/nanocrystalline alloys and ferrites widely used as cores in sensors and electronic control systems, their magnetic properties directly affect the energy efficiency, safety, and intelligent control level of the entire vehicle.

TUNKIA provides comprehensive testing solutions for manufacturers across the magnetic material industry chain, having developed complete testing systems for electrical steel, permanent magnet materials, and soft magnetic materials. These systems have been widely adopted by material manufacturers, motor enterprises, and sensor manufacturers.

TUNKIA Product Portfolio

Electrical Steel Testing

• Online testing: Core loss transverse fluctuation testing, core loss longitudinal distribution testing

• Offline testing: Manual/automatic testing of core loss/magnetic flux density, magnetostriction, reverse bending, insulation resistance, stacking factor, etc.

• Comprehensive performance testing: Comprehensive magnetic performance testing under conditions such as high/low temperature, harmonics, DC bias, full angle, and mechanical stress.

Permanent Magnet Material Testing

• Magnetic parameters: coercivity, remanence, maximum energy product, etc.

• Magnetic characteristic curves: demagnetization curve, magnetization curve, etc.

• Temperature characteristic testing from room temperature to high temperature (up to 500°C).

Soft Magnetic Material Testing

• DC magnetic properties: magnetic parameters such as coercivity, remanence, initial permeability; magnetic characteristic curves such as magnetization curve and hysteresis loop

• AC magnetic properties: magnetic parameters such as specific total loss and specific apparent power; magnetic characteristic curves such as hysteresis loop and loss vs. magnetic flux density curve

2.2 TUNKIA Battery Testing Solution

For automotive battery internal resistance and charge/discharge testing, TUNKIA provides corresponding calibration devices:

TD1480 – Calibration Device for Battery Internal Resistance Testers

TUNKIA has developed a standard specifically for calibrating battery internal resistance testers, based on the principle of simulating AC resistance output. This device features continuously adjustable resistance output, fine adjustment resolution, and high accuracy, meeting the requirements for standards specified in JJF 1620-2017 Calibration Specification for Battery Internal Resistance Testers.

TE4000 – Calibration Device for Battery Charge/Discharge Testers

TUNKIA has developed a dedicated standard with a modular functional structure. This device offers ultra-high integration and good portability, enabling the testing of parameters such as accuracy, stability, and capacity of the charge/discharge process of the equipment under test, as required by JJF 2039-2023 Calibration Specification for Battery Charge/Discharge Testers.

2.3 TUNKIA Sensor Testing Solution

Current sensors and voltage sensors are widely used in the three-electric systems and charging facilities of new energy vehicles.

TUNKIA provides comprehensive testing solutions for sensor R&D and metrology, as well as batch testing solutions for sensor manufacturing. These solutions cover test items for static performance (basic error, hysteresis, repeatability, linearity, etc.) and dynamic performance (response time, frequency bandwidth, frequency response characteristics) of sensors, complying with the testing requirements of the latest national calibration specification Calibration Specification for AC/DC Current Sensors. The main standards used in the testing system are as follows:

The sensor testing system is based on a modular architecture and can provide customized solutions according to user requirements. Currently, the above solutions have been widely adopted by metrology institutes at various levels, national key laboratories, sensor manufacturers, etc., significantly improving sensor testing capability and efficiency, and supporting the development of the new energy industry.

2.4 TUNKIA Shunt Testing Solution

For shunt testing, TUNKIA provides comprehensive solutions:

TE3000 – For R&D and Metrological Calibration

TUNKIA has developed a modular DC shunt verification device. It can be configured with a DC high current source ranging from 120 A to 10 kA according to user requirements, and features very high accuracy and stability, meeting the testing requirements for shunt error, stability, thermal equilibrium time, and other parameters across the full range.

TI6000 – For Production Commissioning and Quality Inspection

TUNKIA has developed a low-resistance analyzer featuring arbitrarily adjustable test current, fast test speed, and a high degree of automation. It is suitable for rapid resistance adjustment and quality inspection on shunt production lines.

2.5 TUNKIA DC Energy Meter Testing Solution

TUNKIA offers the world's most complete DC electrical energy product portfolio, covering DC electrical energy meter verification and type evaluation devices, high-level standard sources and meters, and reference equipment based on quantum technology. The power and energy accuracy covers a range from 5 ppm to 0.05%, making these instruments ideal for value transfer and traceability related to DC electrical energy.

Reference-level Equipment

Based on the ultra-high accuracy of DC-PJVS, combined with a DC ultra-stable power source and a precision DC power and electrical energy measurement standard, high-precision traceability of DC voltage, current, power, and energy over a wide range is achieved, with the best power/energy accuracy (U₉₅) reaching 5 ppm.

High-level Metrological Standards

Including DC standard electrical energy meters and high-accuracy power sources, primarily serving as transfer standards in high-level metrology laboratories.

DC Electrical Energy Meter Verification Device

A multi-position verification device capable of batch verification of starting, creep, basic error, meter constant, and clock daily timing error of DC electrical energy meters.

DC Electrical Energy Meter Type Evaluation Device

Includes dedicated EMC equipment, type evaluation devices, magnetic field generators, etc., providing a complete type evaluation solution capable of addressing testing challenges such as ripple influence, rapid load current change, and EMC tests.

2.6 TUNKIA EV Charger Testing Solution

Addressing various EV charger testing requirements, TUNKIA has developed a range of advanced products, forming a comprehensive EV charger testing solution that covers on-site metrological verification, acceptance inspection and operation & maintenance, vehicle-mounted testing, full-performance type evaluation, traceability calibration, and ultra-fast charging.

Field Portable EV Charger Testing Solution

Various types of portable EVSE testers and dedicated resistive loads for on-site metrological verification of EV chargers.

Field Vehicle-mounted EV Charger Testing Solution

EV charger testing equipment is integrated into fuel-powered or electric vehicles through vehicle modification, forming a highly integrated mobile EVSE testing platform that enables efficient on-site metrological verification/testing of EV chargers.

Full-performance EV Charger Testing Solution

Provides a full-performance testing solution for EV chargers, featuring comprehensive functionality and testing capabilities covering various requirements such as factory inspection, type evaluation, and energy efficiency rating of EV chargers.

EVSE Tester Traceability Calibration

High-accuracy AC-DC electrical energy standard devices (Class 0.01) used for traceability calibration of various EV charger testers, primarily intended for metrology institutes.

Based on the verification concept of "inspection during charging", TUNKIA has launched the TE1000 EV Charger Energy Standard lightweight verification solution.

• The device offers significant advantages such as green and low-carbon operation, extreme portability, and dynamic efficiency.

• The TE1000 (GB/T version) weighs less than 1.7 kg and is operated via a mobile APP. Using an electric vehicle as the load, it performs standard electrical energy metering during the actual charging process, enabling efficient verification by a single operator.

• It also supports multiple communication methods and bidirectional electrical energy metering, aligning with future development such as cloud platform management and V2G (Vehicle-to-Grid).

• It provides a reliable tool for the mandatory verification and operation & maintenance of EV chargers.

Part 3 Operation Videos of Related Products