Road vehicles—Test method of electrical disturbances from conduction and coupling—Part 3: Electrical transient transmission by capacitive and inductive coupling via lines other than supply lines
Road vehicles - Test method of electrical disturbances from conduction and coupling - Part 3: Electrical transient transmission by capacitive and inductive coupling via lines other than supply lines
1 Scope
This document specifies bench test methods to evaluate the immunity of devices to transient pulses coupled to lines other than supply lines.
This document applies to nominal 12 V or 24 V electrical/electronic components of M, N, O and L vehicles
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 21437.1 Road vehicles - Test method of electrical disturbances from conduction and coupling - Part 1: Definitions and general considerations (GB/T 21437.1-2021, ISO 7637-1:2015, MOD)
GB/T 21437.2 Road vehicles - Test method of electrical disturbances from conduction and coupling - Part 2:Electrical transient conduction along supply lines only (GB/T 21437.2-2021, ISO 7637-2: 2011, MOD)
GB/T 33014.4 Road vehicles - Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy - Part 4: Bulk current injection (BCI) (GB/T 33014.4-2016, ISO 11452-4:2005, MOD)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 21437.1 apply.
4 Test conditions
4.1 General
This document describes CCC method, DCC method and ICC method for testing the immunity of electrical system components or devices under test (DUTs) against coupled transient pulses. These tests shall be performed in the laboratory.
Test transient pulses simulate fast and slow electrical transient disturbance, such as transient disturbance caused by inductive load switching and relay contact bounce. The test pulses in this part represent the characteristics of most of the known transient pulses which may occur in the vehicle.
Such pulse tests may be omitted if a device, depending on its function or its configuration, is not subjected to the transient pulses specified in this part. The vehicle manufacturer and the supplier shall define additional transient pulse tests needed.
A test plan shall be written to define the following:
— the test methods to be used;
— the test pulses to be applied;
— the test pulses levels;
— the number of test pulses;
— the DUT operating modes;
— the wiring harness (test versus production);
— the leads to be included in the capacitive coupling clamp, if used;
— the leads to be tested using the direct coupling capacitor method, if used;
— the capacitance values to be used, if the direct coupling capacitor method is used;
— the leads to be included in the inductive coupling clamp, if used; and
— the type of inductive coupling clamp, if the inductive coupling method is used.
The transient pulse test severity levels of DUT shall be mutually agreed upon between the vehicle manufacturer and the supplier, or may be chosen from Annex B.
The applicability of the three different test methods is indicated in Table 1. It is sufficient to select one test method for slow transient pulses and one test method for fast transient pulses.
Table 1 Test method applicability
Transient pulses type CCC method DCC method ICC method
Slow transient pulses 2a Not applicable Applicable Applicable
Fast transient pulses 3a and 3b Applicable Applicable Not applicable
4.2 Standard test conditions
Standard test conditions shall be according to GB/T 21437.1 for the following:
- test temperature;
- supply voltage.
Unless otherwise defined, the tolerance on test severity levels shall be %.
4.3 Ground plane
The ground plane shall be made of 0.5 mm thick (minimum) copper, brass or galvanized steel. The minimum width of the ground plane shall be 1,000 mm, or underneath the entire setup width (excluding power supply and transient pulse generator) plus 200 mm, whichever is larger. The minimum length of the ground plane shall be 2,000 mm, or underneath the entire setup length (excluding power supply and transient pulse generator) plus 200 mm, whichever is larger.
4.4 Test setup
The DUT shall be arranged and connected according to its requirements. The DUT shall be connected to the original operating devices (loads, sensors, etc.) using the test or production harnesses described in 4.5.4, 4.6.4 and 4.7.4. If the actual DUT operating signal sources are not available, they may be simulated.
The DUT shall be placed on a non-conductive, low relative permittivity material (εr≤1.4), at (50±5) mm above the ground plane. If the DUT is locally grounded (maximum length of 200 mm), then the DUT’s ground supply line shall be connected to the ground plane as defined in the test plan.
Grounding of the DUT case to the ground plane shall reflect the vehicle installation and shall be defined in the test plan.
All harnesses shall be placed on a non-conductive, low relative permittivity (dielectric-constant) material (εr≤1.4), at (50±5) mm above the ground plane. All loads, sensors, etc. grounds (lines, metallic cases) are connected to the ground plane using the shortest possible length.
To minimize extraneous capacitive coupling to the DUT, the minimum distance between the DUT and all other conductive structures, such as walls of a shielded enclosure (with the exception of the ground plane underneath the test setup) shall be more than 0.5 m.
4.5 CCC method
4.5.1 General
The CCC method is suitable for coupling the fast transient pulses, particularly for DUTs with a moderate or large number of leads to be tested. It is not suitable for coupling the slow transient pulses.
4.5.2 Generator verification
The transient pulse parameters (see Tables 6 and 7) shall be verified prior to the test according to GB/T 21437.2. Verification shall be performed with the 50 Ω load condition.
4.5.3 Transient pulses level adjustment
The transient pulse generator shall be connected as shown in Figure 1. The transient pulse level is adjusted with a 50 Ω input oscilloscope.
The output of the CCC (no intermediate cable connections) is connected with the oscilloscope through a 50 Ω attenuator with 50 Ω coaxial cable. There shall be no lines routed through the coupling clamp during adjustment. Examples of test severity levels are listed in Annex B.
Note: The open circuit voltage of the transient pulses generator is approximately twice the value of the specific test voltage, due to 50 Ω loading of the attenuator and the oscilloscope.
Key
1——transient pulses generator; 4——50 Ω attenuator;
2——50 Ω coaxial cable (≤1 m); 5——oscilloscope (50 Ω input).
3——CCC;
Figure 1 transient pulses level adjustment - CCC method
4.5.4 DUT test
Ensure that the general test setup conditions defined in 4.4 are applied. The test setup using the CCC is shown in Figure 2.
The DUT cable passing through a CCC shall be agreed between the vehicle manufacturer and the supplier and documented in the test plan. The coupling length is 1 m.
The 12V/24 V supply lines (ground and supply) shall not be included in the CCC. Any other ground or supply line delivered to an auxiliary equipment (sensors, actuators) shall be included in the CCC. If the auxiliary equipment is locally grounded, this local ground connection shall be excluded from the CCC. Any exception about ground or supply lines included in the CCC shall be stated in the test plan.
All lines which are placed in the CCC shall lie flat in single layer (typically 10 to 20 lines). This may require multiple tests to be performed in order to test all the DUT lines.
The hinged lid of the CCC shall be placed as flat as possible to ensure contact with the test harness which shall be positioned as flat as possible. Twisted and shielded wire configurations shall be maintained inside the CCC. The test for a DUT with multiple connectors (single test on all the branches or test on individual branch) or for a harness with more than 10 to 20 lines shall be specified in the test plan.
The distance between the DUT and the CCC, and between peripheral devices and the CCC, shall be greater than or equal to 300 mm. The portions of the lines being tested which are outside the CCC shall be placed at a distance of (50 ± 5) mm above the ground plane and oriented at 90° ± 15° to the longitudinal CCC axis. The lines which are not under CCC test are routed outside the coupling clamp. They shall be placed on a (50 ± 5) mm height insulating support and shall be placed at a minimum distance of 100 mm to the coupling clamp. Arrangement due to additional length shall be defined in test plan.
The DUT shall be placed on the same end of the CCC as the transient pulses generator. The test shall be performed with a total harness length of 1,700 mm.
Foreword II
Introduction V
1 Scope
2 Normative references
3 Terms and definitions
4 Test methods
4.1 General
4.2 Standard test conditions
4.3 Ground plane
4.4 Test setup
4.5 CCC method
4.6 DCC method
4.7 ICC method
5 Test apparatus
5.1 Power supply
5.2 Oscilloscope and probes
5.3 Transient pulses generator
5.4 CCC fixture
5.5 DCC fixture
5.6 ICC fixture
Annex A (Nominative) Calibration fixture used for the ICC test method
Annex B (Informative) Example of test pulse severity levels
B.1 General
B.2 Test pulse severity level
B.3 Example of FPSC application using transient pulses test severity levels
Annex C (Informative) Estimation of the inductive coupling factor
