Technical column
CASES
Interpretation of EMC Specification of Changan Automobile Electrical Components VS-00.35-L-10008
Release time:
2022-12-27 00:00
Source:
Abstract
The electromagnetic compatibility test methods, evaluation indexes and evaluation requirements of test results of automobile electronic parts stipulated by VS-00.35-L-10008 are introduced.
Key words
Electromagnetic compatibility; Automobile electronic parts; Conduction emission; Transient emission; Radiation emission; High current injection; Radiation anti-jamming; Transmitter anti-interference; Low frequency magnetic field immunity; Electrostatic discharge;
introduction
VS-00.35-L-10008 specifies EMC requirements for all automotive electronic and electrical components and subsystems of Chongqing Changan Automobile Co., LTD. It also includes test requirements for AC power ports and HVDC power ports.
General requirements
Electrical components are classified into categories D and C according to the importance of their functions in the safe running of vehicles.
| Function | Description |
|
D |
Advanced Driver assistance systems (ADAS), active safety systems, passive safety systems and related sensors and bus communication. |
|
C |
Functions, sensors and bus communication that affect the driver's driving or control of the vehicle or affect the judgment of other users on the road; Chassis stability system, brake system, engine speed stability, transmission gear stability, EV powertrain stability, cruise control function, drive motor or engine speed limit; Drivers and passengers can feel the subjective function and bus communication, involving all electrical functions in the product specification; Vehicle data acquisition and recording function and bus communication. |
According to the performance requirements of DUT functions, it is divided into 2 levels:
| Grade | Description |
|
Ⅰ |
During and after the re-application of harassment, the device or system shall be able to perform all functions of the pre-design and pre-test, and its performance shall be any different from its operating condition before the application of harassment. Advanced driver assistance systems (ADAS) should also maintain vehicle safety in the event of electrical, electronic, mechanical failures or software errors. |
|
Ⅲ |
The device or system does not perform one or more functions designed in advance to the extent that safe driving is not affected and the subjective comfort of passengers should not be affected during the harassment period, but can automatically return to the pre-test working state or resume normal work in accordance with the designed fail-safe mode immediately after the harassment is stopped. For example, the display screen in the static test image flicker immediately return to normal; A confirmation message is displayed on the UI after the power is restored. |
-
Detailed requirements for test items
The EMC test items for components and their systems depend on the type of electronic and electrical components they contain. Different components have different EMC test project requirements.Class P: Electrical components or modules during the passive period. For example: resistor, capacitor, anti-reflex/clamp diode, thermistor, varistor, PTC heater without control circuit. Mechanical contact switch LED backlight.
Class R: inductors, electromagnetic relays, solenoid valves, coils, door locks and horns
BM Class: brush commutator motor
Class EM: Motor with internal control circuit
Class A: Electrical modules containing active devices. Examples include: in-car entertainment systems, switching power supplies, controllers, amplifiers, displays, LED lights containing controllers.
Class AS: Electrical components or modules that are powered by a stable power source in other modules. Such devices are usually sensors that provide input signals to the controller. 12V components: Power line conducted disturbance and conducted disturbance rejection tests shall be tested. 5V components: Do not test the power line conduction disturbance, but test the conduction immunity test of 5V voltage.
AM class: Modules containing magnetic sensors or modules with magnetic sensors attached externally. For example, electromagnetic sensors, Hall sensors, and devices that send and receive signals at the frequency of 50 HZ-300 KHZ.
Class AX: Electrical parts with internal inductive devices such as motors and electrical parts that control external inductive devices. For example, BCM, EPS, PEPS, TCU, BMS, VCU, DC/DC, IPU, OBC, etc.
AW class: no external modules such as remote key, smart key, TPMS transmitter, RFID.
AC: An electrical component that connects to or outputs 220V/380V AC power, such as a charger and 220V inverter.
HV: An electrical component that accesses or outputs a high-voltage DC power supply, usually connected to the power supply through shielded cables and shielded connectors, such as motor drivers, DC converters, chargers, electric compressors, electric heaters, and battery packs.
See the following table for the test content of different types of electrical components (« denotes need to be tested; ☆ denotes whether the test is determined according to its working principle, working frequency and installation position. For example, when PEPS tests MFE, intentional emission of magnetic field frequency band is exempted, and DUT receiving GNSS signals is exempted from GNSS frequency band.)
After the electrical components pass the test, due to the adjustment of the design scheme, it is necessary to supplement the applicable electromagnetic compatibility tests according to their categories in the following table.
-
- Radiation emission: RE
Environmental requirements:
-- Room temperature, relative humidity below 95%;
-- The background noise of the darkroom is 6dB below the limit line.
The frequency range of radiation emission measurement is 150kHz ~ 5.925GHz. Refer to CISPR 25 for test methods.
Radiation emission test arrangement：
Test frequency band and test antenna requirements: vertical polarization is adopted below 30MHz, and vertical and horizontal polarization is adopted above 30MHz for test.
Radiation emission limit line is basically equivalent to CISPR 25 level 3 requirements, detailed as follows:
-
- Power line conducted emission: CEV
Test frequency range: 9kHz~110MHz
Only EUT power cables are measured. The test method and test equipment refer to CISP 25 standard.
EUT power supply conduction emission test layout
The transmission emission limit line of the power cord is basically equivalent to the requirements of CISPR 25 Level 3. Details are as follows:
For short-time working parts and short-time working conditions, the CEV of broadband disturbing parts is only required to meet the disturbance limit of 150kHz~30MHz, and the CEV of short-time working conditions is required to meet the disturbance limit of 9kHz~30MHz, and the limit of peak and average detection can be increased by 6dB.
-
- Control and signal line conduction emission: CEC
Test frequency range: 100Hz~110MHz
Only EUT cables except power cables should be measured. The test method and test equipment should refer to CISP 25 standard.
Control and signal line conduction emission test layout
Control and signal line transmission emission limit line, except 100Hz~0.15MHz frequency band, other frequency band limit is basically equivalent to CISPR 25 level 3 requirements, detailed as follows:
The disturbance limit of 150kHz~30MHz for short time working parts can be increased by 6dB.
-
- Low frequency magnetic field emission: MFE
Electric vehicle charger, switching power supply, fan with PWM speed regulation, oil pump controller with PWM speed regulation and other working frequency in the sub-range and the shell is not completely shielded components should meet this requirement.
The test method and test equipment refer to GJB 151B-RE101 standard, and the test frequency is 0.02kHz~400kHz.
Low frequency magnetic field emission test layout
Low frequency magnetic field emission limit requirements are as follows:
PEPS system again 120kHz~140kHz exemption limit requirements, Qi wireless charger again 110kHz~205kHz exemption limit requirements, normal wireless charging system again 80kHz~90kHz, 160kHz~180kHz exemption limit requirements.
-
- Transient conducted emission: CTE
To test the transient voltage emission of the working power lines of components, refer to ISO 7637-2 for test methods and test equipment. Regulations on oscilloscope requirements (sampling rate, storage depth, bandwidth), voltage probe requirements (3dB bandwidth, capacitance, rise time), Settings and so on have strict requirements.
Oscilloscope:
a) Digital oscilloscope; b) Sampling rate ≥2GSa/s; c) Storage depth ≥2M sampling points; d) Bandwidth ≥500MHz.
Voltage probe:
a) Attenuation ratio 1:100; b) -3dB bandwidth is 250MHz; c) Capacitance < 4pf; d) Rise time < 2ns.
Transient conduction emission test arrangement
The transient voltage amplitude generated by the DUT on any of its power lines should meet the following requirements when the switch is closed and disconnected:
| DUT voltage level | 12V system |
| Maximum level |
+75 V |
| Minimum level |
-100 V |
-
- Radiation immunity: RI
To examine the resistance of parts to narrow-band electromagnetic energy radiation, test methods and test equipment refer to ISO 11452-2.
The test frequency ranges from 80MHz to 2000MHz.
The test layout is as follows:
Radiation immunity test layout
Test signal parameters are as follows:
According to DUT function type, test grade requirements and performance criteria are as follows:
| Interference level | Functional level requirement | |
|
C |
D |
|
| Level 1 |
Ⅰ |
|
| Level 2 |
|
Ⅰ |
-
- High current injection: BCI
The resistance of parts to narrow-band electromagnetic energy radiation was examined by referring to the alternative method in ISO 11452-4.
Duts that transmit signals using shielded cables (cameras, engine sensors, microphones, switch panels, etc.) or twiped-pair cables or are not grounded at the far end and all cables are connected to one controller are not tested for differential mode BCI.
Only the power cord and LIN bus components of the BCI test grade is Ⅲ.
The test layout is as follows:
In amplitude modulation mode, the modulation frequency is 1kHz, the modulation depth is 80%, and the frequency residence time is not less than 2s. The test signal parameters are as follows:
| Injection mode |
Frequency（MHz） |
Step size（MHz） |
Modulation mode |
Level 1（mA） |
Level 2(mA) |
| Differential mode |
0.1~1 |
0.05 |
CW;AM 80% |
40 |
40 |
|
1~30 |
1 |
CW;AM 80% |
60 |
60 |
|
| Common mode |
1~200 |
1 |
CW;AM 80% |
100 |
200 |
|
200~400 |
2 |
CW;AM 80% |
100 |
200X200/f（MHz） |
According to DUT function type, test grade requirements and performance criteria are as follows:
| Interference level | Injection mode | Functional level requirement | ||
| Only the power supply and LIN bus components |
C |
D |
||
| Level 1 | Differential mode |
Ⅲ |
Ⅰ |
N/A |
| Common mode |
Ⅰ |
Ⅰ |
N/A |
|
| Level 2 | Differential mode |
Ⅲ |
N/A |
Ⅰ |
| Common mode |
Ⅰ |
N/A |
Ⅰ |
|
-
- Transmitter immunity: PTI
The test method is referred to ISO 11452-9, and the test distance depends on the actual application of DUT.
The specification specifies the test antenna models, Schwarzbeck SBA9113+420NJ and SBA9119+422NJ.
Completely shielded metal surfaces do not need to be tested.
Emitter immunity test layout
Transmitter immunity test antenna and DUT relative position
| DUT housing and harness description | Requirement on distance between RF antenna and DUT |
| The distance between the DUT shell and the wiring harness and the transmitter or the user can contact the position is more than 200mm |
50mm |
| The DUT shell and harness are within 200mm of the transmitter or the position that the user may touch |
10mm |
For modules without wiring harnesses (such as smart keys and RKE keys), the wiring harnesses and LISN involved in the test layout are not applicable.
Typical test location method is the same as 11452-9, as follows:
Schematic diagram of transmitter immunity antenna test position
Test signal parameters are as follows:
According to DUT function type, test grade requirements and performance criteria are as follows:
| Interference level | Functional level requirement | |
|
C |
D |
|
| Level 1 |
Ⅰ |
Ⅰ |
| Level 2 |
Ⅲ |
Ⅲ |
-
- Low frequency magnetic field immunity: MFI
The ability of parts to resist magnetic field and interference is examined. The test method and test equipment refer to ISO 11452-8.
The resonance frequency of the magnetic field radiation ring should be higher than 300 kHz, and the coil diameter should be 120mm.
Low frequency magnetic field immunity test layout
Divide each surface of the DUT into 100 X 100 mm squares and align the radiant ring with the center of the squares. The distance between the radiant ring and the DUT surface is 50mm. The dwell time is not less than 2s, and if the DUT response time is longer than 2s, the dwell time is extended appropriately.
Low frequency magnetic field immunity test grade and functional status requirements are as follows:
-
- Electrostatic discharge: ESD
Test the antistatic discharge ability of the parts, test methods and test equipment meet the requirements of ISO 10605.
The electrostatic discharge test requires high humidity, so the test should be conducted in an environment of 20% to 40%.
The test is divided into power off state electrostatic discharge test and EUT operating mode electrostatic discharge test.
Passive mode discharge test
-- Discharge networks are 150pF and 330Ω;
-- DUT All negative poles/ground wires are connected to the ground plate through the ground bus or wires no longer than 200mm;
- Discharge any position that may be contacted during the process of packaging, installation and dismantling;
- Discharge at least three times for each discharge position and voltage at a frequency of 1Hz.
-- Typical test layout is as follows:
Test layout in power off state
Direct coupling in active mode
- If the EUT is in active mode, the input and output must be connected.
- Any position that may be touched by users and maintenance personnel shall be tested by discharge;
-- Apply ±25KV electrostatic discharge to DUTs that can be reached directly from outside the vehicle and are installed in the passenger compartment but can be reached directly from outside the vehicle. For example, rearview mirror, logo light, camera, door knob switch, trunk switch, electrical components of engine room, LED lamps outer surface gap, function buttons on steering wheel, light control handle, wiper handle, key, laser radar, MM radar wave, reversing radar probe, outside antenna, etc.
- Discharge at least three times for each discharge position and voltage. The maximum risk test point is 10 times. Discharge frequency is 1Hz.
Electrostatic discharge position, voltage level, and function status requirements:
The antistatic requirements of an LCD screen are as follows:
FIG. 12 Layout of EUT test bed in active mode
-
- AC power port test requirements
Applicable object: vehicle inverter and vehicle charger
The output power is 80%-90% of the rated maximum power.
-
-
- Harmonic transmitting harmonic
-
Test instrument reference GB 17625.1, GB/T 17626.7
The inverter or charger is placed on a 50mm thick insulator, and the output voltage is AC 220V± 2%@ 50Hz. The L end is connected to the measuring instrument. When testing the inverter, disconnect the external AC power supply of the test device to the tested part to avoid short circuit.
The layout is as follows:
When the load of the inverter is on or off before the test, the harmonic current and power within the first 10S after the switch action are not considered. The measurement period is set to be no less than 150S so that the repeatability of measurement is better than ±5%.
The harmonic current limit shall meet the Class A limit specified in GB 17625.1.
-
-
- Voltage changes, fluctuations, Flicker
-
Test instruments refer to IEC 61000-3-3
The inverter or charger is placed on a 50mm thick insulator, and the output voltage is AC 220V± 2%@ 50Hz. The L and N terminals need to be connected with reference impedances of 0.39Ω and 0 respectively. 26Ω. When testing the inverter, disconnect the external AC power supply of the test device to the tested part to avoid short circuit.
The layout is as follows:
Voltage variation, fluctuation and flicker emission limits shall meet the requirements in the following table:
-
-
- Conduction emission AC-CEV
-
The test instrument refers to the requirements of CSIPR 22, and the test frequency band is 9kHz-110MHz.
AC input and output are 220V±2% and 50Hz. The 12V system and the ground of the charger enclosure (floating ground, a separate test table can be used) shall be isolated from the AC AMN and the laboratory ground, and the floating ground and the laboratory shall be connected by a 1 megohm resistance. The inverter is placed on a 50mm thick insulator.
The transmitted emission limits of the AC power cable shall meet the requirements in the following table:
-
-
- Electric fast transient pulse group disturbance immunity AC-EFT
-
The test object is the charger.
Instruments and equipment meet the requirements of IEC 61000-4-4.
AC input and output are 220V±2% and 50Hz. The 12V system and the ground of the charger enclosure (floating ground, a separate test table can be used) shall be isolated from the AC AMN and the laboratory ground, and the floating ground and the laboratory shall be connected by a 1 megohm resistance.
The immunity of the charger should meet the requirements in the following table. The function and performance of the DUT shall be affected in any way during and after the test.
-
-
- AC-SURGE
-
The test object is the charger.
Instruments and equipment meet the requirements of IEC 61000-4-5.
AC input and output are 220V±2% and 50Hz. The 12V system and the ground of the charger enclosure (floating ground, a separate test table can be used) shall be isolated from the AC AMN and the laboratory ground, and the floating ground and the laboratory shall be connected by a 1 megohm resistance.
The immunity of the charger should meet the requirements in the following table. The function and performance of the DUT shall be affected in any way during and after the test.
-
- HVDC power port test requirements
Applicable objects: motor driver, DC converter, vehicle charger/high voltage inverter, electric compressor, electric heater, battery pack and other high voltage DC power supply electric vehicle special components.
The output power is 80%-90% of the rated maximum power.
-
-
- The high voltage DC power cable transmits HV-CEV
-
The test instrument refers to CISPR 25 Ed.4.0, and the test frequency band is 9kHz-110MHz.
The cable is placed on a 50mm thick insulator, and the housing of the tested part is connected to the test table. The HV cable can be extended to 0.5-1.7 meters because of the layout space.
Typical test layout is as follows:
The transmission emission limits of the HVDC power cable should meet the following requirements:
-
-
- HV-Lvcoupling attenuation
-
The high voltage DC electrical components are not connected to the power supply, and are connected using short wiring harnesses and connectors.
The test instrument meets the requirements of CISPR 25 Ed.4.0.
The DUT and cable are placed on a 50mm thick insulator, and the housing of the tested part is connected to the test table. HV cables and their connectors must be of the same type as those used in the vehicle. The cable length shall not exceed 200mm.
The interference sweep signal is injected from the HVDC power line port in the frequency band of 9kHz-110MHz, and the model amplitude coupled to the low-voltage port is measured.
The test results of high and low voltage coupling attenuation are not evaluated. The test results are only used as reference for the test results of conduction emission of high voltage port and shielding attenuation of high voltage wire harness.
-
-
- HV-BCI
-
The test instrument and arrangement refer to ISO 11452-4, and the test frequency band is 100kHz-400MHz.
The cable is placed on a 50mm thick insulator, and the connection mode between the shell of the tested part and the test table is consistent with that of the vehicle. The length of the HV cable should be 0.5m to 1.7m. The HV cable and its connectors should be the same as those used in the vehicle. The 50 ohm port of the HV-LISN is connected to the 50 ohm terminal resistor.
The anti-interference performance of high voltage DC power line with large current injection should meet the following table requirements:
The test results meet the requirements in the following table:
4.Conclusion
The EMC technical requirements of Changan automobile electronic parts, including equipment requirements, test methods, etc., refer to CISPR 25, ISO series or IEC series basic standards, no special requirements, only in the limit requirements, immunity test grade slightly adjusted/changed.