Detail of GB/T 21437.3-2012

Introduction of GB/T 21437.3-2012

1 Scope This part of GB/T 21437 establishes a bench top test for the evaluation of the immunity of devices under test (DUTs) to transient transmission by coupling via lines other than supply lines. The test transient pulses simulate both fast and slow transient disturbances, such as those caused by the switching of inductive loads and relay contact bounce. Three test methods are described in this part: ——the capacitive coupling clamp (CCC) method; ——the direct capacitive coupling (DCC) method; and ——the inductive coupling clamp (ICC) method. Note: The applicability of the three test methods is shown in Table 1. Only one test method need be selected for slow transients and only one method need be selected for fast transients. This part applies to road vehicles fitted with nominal voltage 12V, 24V or 42V electrical systems. For transient immunity, Annex B provides recommended test severity levels in line with the functional performance status classification (FPSC )) principle described in GB/T 21437. 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 21437.1-2008 Road vehicles - Electrical disturbances from conduction and coupling - Part 1: Definitions and general considerations (ISO 7637-1:2002, IDT) GB/T 21437.2-2008 Road vehicles - Electrical disturbances from conduction and coupling - Part 2: Electrical transient conduction along supply lines only (ISO 7637-2:2004, IDT) ISO 11452-4 Road vehicles - Component test methods for electrical disturbances from narrowband radiated elec-tromagnetic energy - Part 4：Bulk current injection (BCI) 3 Test methods 3.1 General This part describes methods for testing the immunity of electrical system components or devices under test (DUTs) against coupled transients. These tests shall be performed in the laboratory. The test pulse severity levels should be mutually agreed upon between the vehicle manufacturer and the supplier prior to the test. The test pulses defined are typical pulses which represent the most of characteristics of the actual transients which may occur in the vehicle. In special cases, it may be necessary to apply additional test pulses. Some test pulses may be omitted if a device, depending on its function or its configuration, is not influenced by comparable transients in the vehicle. It is part of the vehicle manufacturer's responsibility to define the test pulses needed for specific components. A test plan shall be written to define

Contents of GB/T 21437.3-2012

Foreword i Introduction iii 1 Scope 2 Normative references 3 Test methods 3.1 General 3.2 Standard test conditions 3.3 Ground plane 3.4 Test set-up 3.5 Application of transient test pulses 4 Test instrument description and specification 4.1 Power supply 4.2 Oscilloscope 4.3 Test pulse generator 4.4 Capacitive coupling clamp 4.5 Direct coupling capacitor 4.6 Inductive coupling clamp Annex A (Normative) Calibration fixture used for the ICC test method Annex B (Informative) Example of test severity levels associated with functional performance status classification Annex C (Informative) Estimation of the inductive coupling factor