Definition: Electromagnetic Compatibility (EMC) testing evaluates the adaptability of electronic devices in electromagnetic environments, ensuring they operate normally in complex electromagnetic interference backgrounds while not adversely affecting other devices or systems. EMC testing primarily examines the electromagnetic interference (EMI) emitted by the device itself and its resistance to external electromagnetic interference (EMS), serving as a key indicator for measuring the reliability and safety of electronic products.
EMI Testing Project Details
The core purpose of EMI testing is to confirm whether the electromagnetic energy generated during product operation will interfere with the surrounding environment, such as affecting human health, power systems, or other electronic devices. Main testing content includes:
Radiated Interference Testing
Evaluates electromagnetic energy emitted by equipment through space
Conducted Interference Testing
Measures electromagnetic interference transmitted by equipment through paths like power lines
Harmonic Current Interference Testing
Detects the impact of nonlinear loads on grid harmonics
Voltage Fluctuation and Flicker Testing
Confirms whether equipment causes voltage instability during operation
EMS Immunity Testing Projects
EMS testing aims to determine whether equipment can continue normal operation when exposed to external electromagnetic interference. Typical test items include:
- Electrostatic Discharge (ESD) Testing
- Radiated Immunity (RS) Testing
- Conducted Immunity (CS) Testing
- Voltage Dips and Interruptions Testing
- Surge Immunity Testing
- Electrical Fast Transient (EFT) Testing
Key Role of Anechoic Chambers in EMC Testing
Anechoic chambers are indispensable venues in EMC testing, ensuring the electromagnetic environment is fully controlled during testing. They effectively shield external interference and absorb redundant signals, ensuring the accuracy of EMI and EMS tests.
Automotive EMC Testing Standard System
Based on international and domestic standards such as ISO 7637-2:2024 and GB/T 21437-2023, vehicle EMC testing evaluates vehicle performance in various electromagnetic environments. With the rapid growth in the number of onboard electronic devices and the popularization of electric vehicle high-voltage systems, vehicles face more complex electromagnetic environments, making vehicle-level EMC testing particularly critical.
EMC standards are broadly divided into three categories:
- International Standards: Such as IEC, CISPR, ISO
- National or Regional Standards: Such as China GB standards, U.S. SAE standards
- Corporate Standards: Standards established by major vehicle manufacturers, typically more stringent
Vehicle manufacturers not only need to meet national regulations but often impose higher requirements on the conduction, radiation, transient interference, and anti-interference capabilities of electronic components through their own standards.
Special Challenges for Electric Vehicle EMC
The high voltage and large current characteristics of electric vehicle drive systems require enhanced shielding and anti-interference capabilities in their design. Additionally, their coupling with charging equipment may cause grid pollution. Therefore, besides testing, systematic EMC design measures should be taken in materials, wiring, and module layout.
Vehicle External Electromagnetic Radiation and Immunity Requirements
External Electromagnetic Radiation Requirements
During vehicle operation, it must not release electromagnetic energy exceeding standard limits to the outside, to avoid interfering with external communication equipment or endangering human health. Test reference standards include GB 14023-2023, GB 34660-2023, and GB/T 18387-2023. Key test conditions:
- Static state (all systems in the vehicle powered on)
- Dynamic driving conditions at different speeds
- Battery charging state
Electromagnetic Interference Immunity
Vehicles must be able to resist external electromagnetic waves, with testing covering the 20MHz-6GHz frequency band. Test conditions include:
- Vehicle driving steadily at 50km/h, all electrical equipment turned on
- State of Charge (SOC) between 20%-80%
Onboard Electrical Equipment EMC Requirements
Electromagnetic Radiation Interference Control
High-power electrical appliances such as air conditioners and motors should be equipped with interference suppression devices. EMI testing is conducted according to GB/T 18655-2023 standard, with EMI testing recommended not lower than Level 3 limits. Main test scenarios:
- Static power-on
- 40km/h steady-state driving
- Charging state
Immunity Requirements
Onboard equipment should be able to withstand electromagnetic radiation from onboard communication equipment (such as radios, T-Box) without malfunctioning.
2025 EMC Testing New Trends
Smart Connected Vehicles
More stringent EMC testing requirements for V2X communication
High-Voltage Fast Charging Systems
EMC design challenges for 800V high-voltage platforms
Autonomous Driving Sensors
Electromagnetic compatibility of cameras, radar, and lidar
Software-Defined Vehicles
OTA update requirements for continuous EMC compliance
Common EMC Terminology Explanation
Professional EMC Testing Services
Our laboratory is equipped with internationally advanced testing equipment, providing comprehensive automotive EMC testing solutions, including:
- Vehicle-level EMC testing and certification
- Component-level EMC testing and rectification
- Pre-testing and diagnostic services
- Technical consulting and training services
With rich industry experience and a professional technical team, we have provided reliable EMC testing services for numerous automobile manufacturers and component suppliers, ensuring products comply with regulatory requirements in global markets.
Frequently Asked Questions
Electric vehicles present unique EMC challenges due to their high-voltage power systems, fast-switching electronics, and complex communication networks. These systems can both generate significant electromagnetic interference and be susceptible to external interference, potentially affecting vehicle safety, performance, and regulatory compliance.
A comprehensive vehicle-level EMC test program typically requires 3-5 days in an anechoic chamber, depending on the number of test conditions, vehicle configurations, and any required troubleshooting. Component-level testing may take 1-2 days per component.
EMC test failures can lead to significant project delays, costly redesigns, and potential regulatory non-compliance. In some markets, vehicles cannot be sold without passing mandatory EMC tests. Additionally, EMC issues discovered after production can result in expensive recalls and damage to brand reputation.
Wireless charging introduces additional EMC challenges due to the strong electromagnetic fields required for power transfer. These systems must be designed to minimize interference with other vehicle systems while maintaining immunity to external interference, requiring specialized testing beyond traditional conducted charging systems.
While some EMC issues can be addressed through filtering, shielding, or software updates post-design, fundamental EMC problems often require significant hardware changes that are costly and time-consuming. This is why EMC considerations should be integrated from the earliest stages of vehicle design.
