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1. Analysis of the Necessity of Electromagnetic Compatibility Testing
Household PV-storage-charging products integrate various power electronic devices such as photovoltaic inverters, power conversion systems (PCS), and charging modules. Their internal high-frequency switching actions (e.g., IGBT switching frequency harmonics) and complex topologies are prone to generate electromagnetic interference (EMI). Core components within such equipment (such as high-frequency switching transistors, inductors, capacitors, and control circuit boards) produce high-frequency harmonics and switching noise during operation, which may form electromagnetic disturbances through conduction or radiation paths.
For example, excessive conducted emissions from a photovoltaic inverter can directly affect the home electrical environment, causing malfunctions in other electronic devices; abnormal radiated emissions may interfere with the normal operation of sensitive equipment like communication devices. Simultaneously, if grid-connected photovoltaic power sources neglect electromagnetic emission control, it could lead to inter-device interference, communication failures, or even circuit damage, further highlighting the necessity of electromagnetic disturbance control.
Key Impact
The home environment contains numerous devices sensitive to electromagnetic disturbances, such as medical equipment and communication devices. EMC testing is necessary to verify the "do not interfere with others" capability of household PV-storage-charging products.
Regulatory Requirements
Electromagnetic compatibility testing is a mandatory requirement for market access of household PV-storage-charging products. Regulations in various countries (such as the EU EMC Directive 2014/30/EU) explicitly require EMC testing as a prerequisite for product launch.
Products that fail testing cannot enter target markets and may face recall risks, accompanied by high rework costs, brand reputation damage, and potential legal risks.
Technical Advantages
EMC testing can effectively expose product design flaws, improve long-term operational reliability, and reduce after-sales maintenance costs. Testing helps identify issues such as insufficient filter circuits and poor grounding.
2. Domestic and International Electromagnetic Compatibility Testing Standards
International Standard System
The international standard system focuses on universality and compatibility, establishing a comprehensive framework covering electromagnetic emissions (EMI) and electromagnetic immunity (EMS). Among these, the IEC 61000 series serves as the foundational standard, specifying general methods and technical requirements for EMC testing, providing a unified compliance basis for various electrical and electronic equipment.
| Standard Number | Scope of Application | Key Requirements |
|---|---|---|
| IEC 61000-3-2 | Harmonic current emissions for low-voltage equipment | Applicable to equipment with input current ≤16A per phase |
| IEC 61000-3-3 | Voltage fluctuations and flicker | Equipment with rated current not exceeding 16A |
| IEC 61000-6-3 | Residential, commercial, and light industrial environments | Frequency range 0Hz to 400GHz |
| IEC 61000-6-4 | EMI requirements for industrial environments | Differentiated specification system based on environment |
Domestic Standard System
The domestic electromagnetic compatibility standard system is highly aligned with international standards in terms of technical content. Core testing standards such as the GB/T 17626 series are equivalent to the IEC 61000-4 series, covering key immunity items including electrostatic discharge (GB/T 17626.2), radio-frequency electromagnetic field immunity (GB/T 17626.3), electrical fast transient/burst immunity (GB/T 17626.4), surge immunity (GB/T 17626.5-2019), and more.
| Domestic Standard | Corresponding International Standard | Test Item/Scope |
|---|---|---|
| GB/T 17626 series | IEC 61000-4 series | Electrostatic discharge / RF radiation / Electrical fast transient, etc. |
| GB 9254 | CISPR 32 | Radio disturbance for information technology equipment |
| GB 4824 | CISPR 11 | Emissions for industrial, scientific, and medical (ISM) equipment |
| GB 17625.1 | IEC 61000-3-2 | Harmonic current emissions |
| GB 17625.2 | IEC 61000-3-3 | Voltage fluctuations and flicker |
3. Core Test Items and Technical Requirements
Electromagnetic Interference (EMI) Testing
Electromagnetic Interference (EMI) testing aims to control the electromagnetic disturbances emitted by household PV-storage-charging products to the external environment and other equipment. It primarily includes four core test items: conducted emission, radiated emission, harmonic current, and voltage flicker. Each item strictly regulates interference characteristics in different frequency bands and their impact on the power grid.
| Test Item | Frequency Range | Main Interference Source | Test Method | Applicable Standard |
|---|---|---|---|---|
| Conducted Emission | 150kHz-30MHz | Common-mode interference from switching power supplies, etc. | Use LISN to isolate grid background noise, measure interference level via EMI receiver | CISPR 16, CISPR 32 |
| Radiated Emission | 30MHz-1GHz (extendable to 6GHz) | Improper PCB layout, unshielded high-frequency modules, etc. | Receive electromagnetic field signals using an antenna in an anechoic chamber, scan full frequency band electric field strength via EMI receiver | CISPR 11, FCC Part 15 |
| Harmonic Current | 2nd-40th harmonic (100Hz-2kHz) | Current distortion caused by nonlinear loads | Measure using a harmonic analyzer under idealized AC power supply conditions | IEC 61000-3-2, GB 17625.1 |
| Voltage Flicker | - | Power variations of the equipment (e.g., switching on/off, load changes) | Simulate equipment switching or load changes, measure short-term flicker (Pst) and long-term flicker (Plt) | IEC 61000-3-3, GB 17625.2 |
Electromagnetic Immunity (EMS) Testing
Electromagnetic Immunity (EMS) testing aims to verify the ability of household PV-storage-charging products to resist external interference and maintain stable operation in complex electromagnetic environments. The results are directly related to product reliability and serve as a core verification method to ensure the equipment is unaffected by electromagnetic disturbances in practical use.
4. Test Equipment and Environmental Requirements
Core Test Equipment
The performance of core test equipment is fundamental to ensuring the accuracy of electromagnetic compatibility testing for household PV-storage-charging products. Equipment selection must strictly comply with test standard requirements and cover key aspects such as interference signal capture, conducted/radiated interference measurement, and immunity simulation.
| Equipment Type | Key Performance Parameters | Compliant Standards |
|---|---|---|
| Spectrum Analyzer/EMI Receiver | Frequency range covers 9kHz~6GHz | CISPR series |
| LISN | Type: Single-phase/Three-phase Current: 16A Impedance: 50Ω |
EN55032, EN55014-1 |
| Radiated Immunity Test System | Frequency coverage: 9kHz~6GHz Field strength can reach 10V/m or above (compliant with IEC 61000-4-3) |
IEC 61000-4-3 |
| Electrostatic Discharge Simulator | Discharge voltage: ±30kV (air/contact) | IEC 61000-4-2 |
| Surge Generator | Pulse waveform: 1.2/50-8/20μs Voltage range: ±5kV |
IEC 61000-4-5 |
| Anechoic Chamber | Frequency coverage: 9kHz~18GHz | IEC 61000-4-3 |
Test Environment Requirements
Strict environmental control is a core prerequisite for ensuring the validity of Electromagnetic Compatibility (EMC) testing. Its design must meet three objectives: interference isolation, parameter stability, and compliance verification.
| Test Type | Standard Number | Temperature Range | Humidity Requirement | Duration | Operating State |
|---|---|---|---|---|---|
| Low Temperature Operating Test | GB/T2423.1 | -20℃ or -25℃ | - | 24 hours | Powered on |
| High Temperature Operating Test | GB/T2423.2 | +40℃ or +60℃ | - | 24 hours | Powered on |
| Constant Damp Heat Test | GB/T2423.3 | +40℃ or +60℃ | 90% RH | 48 hours | Not powered on |
5. Compliance and Market Access Strategy
Compliance is the core prerequisite for household PV-storage-charging products to enter target markets, with specific requirements varying due to differences in regional market regulatory systems.
EU Market
Implements the mandatory CE marking system, requiring products to bear the CE mark and submit EMC test reports compliant with EN standards, such as EN 55032 (CISPR 32) for electromagnetic disturbance limits of information technology equipment.
Chinese Market
Implements CCC mandatory certification. Products that fail EMC testing are strictly prohibited from sale. Core standards include GB 9254 (equivalent to international standard CISPR 32) and GB/T 34131.
US Market
Regulated under FCC Part 15B for unintentional radiators, with limits stricter than those for industrial equipment (Class A). Additionally, energy storage inverters require UL 9540 certification.
Product Standard Selection
The selection of product standards should be determined comprehensively based on the target market, product category, and usage environment. From a market perspective, exports to the EU require compliance with EN 55032 Class B, domestic sales require compliance with GB 9254, and the US market requires adherence to FCC Part 15B.
Certification Strategy Recommendation
To reduce the risk of certification failure, companies need to develop a systematic compliance strategy. During the R&D phase, preliminary EMC testing should be conducted, using near-field probes to locate radiation interference sources, and targeted optimization of filter design or shielding measures should be implemented.
6. Conclusion and Recommendations
As the core equipment of home energy systems, the electromagnetic compatibility (EMC) performance of household PV-storage-charging products is directly related to grid safety, user experience, and market access. It is a necessary step in product certification and a key factor in ensuring the safe and stable operation of equipment and enhancing market competitiveness.
Early Testing Involvement
Conduct EMC pre-testing and preliminary assessments during the product R&D phase and integrate them throughout the entire process from design and production to shipment to avoid high late-stage modification costs.
Adaptive Standard Selection
Select appropriate international or domestic standards based on the target market. For international markets, refer to standards like IEC 62920 and the IEC 61000 series; for the domestic market, comply with standards such as GB/T 34131.
Design Optimization
Adopt low-noise topologies (e.g., LLC resonant inverters), strengthen PCB grounding and filtering design (e.g., adding common-mode inductors, X/Y capacitors at DC ports), and select EMC-compliant components.
Final Conclusion
Through systematic EMC testing and design optimization measures, the electromagnetic compatibility performance of household PV-storage-charging products can be effectively enhanced, promoting their safe, reliable, and compliant application in the global market.
