Detail of GB/T 21437.2-2008

Introduction of GB/T 21437.2-2008

Codeofchina.com is in charge of this English translation. In case of any doubt about the contents of English translation, the Chinese original shall be considered authoritative. GB/T 21437 consists of the following parts, under the general title Road Vehicles — Electrical Disturbances from Conduction and Coupling: — Part 1: Definitions and General Considerations; — Part 2: Electrical Transient Conduction along Supply Lines Only; — Part 3: Electrical Transient Transmission by Capacitive and Inductive Coupling Via Lines Other Than Supply Lines. This part is Part 2 of GB/T 21437. It is identical with International Standard ISO 7637-2:2004 Road Vehicles — Electrical Disturbances from Conduction and Coupling — Part 2: Electrical Transient Conduction along Supply Lines Only. Editorial changes are as follows: addition of the Notes of UA and UB in Table 1. Annexes A, C and D of this part are normative, and Annexes B, E and F are informative. This part was proposed by National Development and Reform Commission. This part is under the jurisdiction of National Technical Committee of Auto Standardization. Road Vehicles — Electrical Disturbances from Conduction and Coupling — Part 2: Electrical Transient Conduction along Supply Lines Only 1 Scope This part specifies bench tests for testing the compatibility to conducted electrical transients of equipment installed on passenger cars and light commercial vehicles fitted with a 12 V electrical system or commercial vehicles fitted with a 24 V electrical system — for both injection and the measurement of transients. Failure mode severity classification for immunity to transients is also given in this part. This part is applicable to these types of road vehicle, independent of the propulsion system (e.g. spark ignition or diesel engine, or electric motor). 2 Normative References The following normative document contains provisions which, through reference in this text, constitute provisions of this part of GB/T 21437. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. GB/T 21437.1 Road Vehicles — Electrical Disturbances from Conduction and Coupling — Part 1: Definitions and General Considerations (GB/T 21437.1-2008, ISO 7637-1:2002, IDT); ISO 8854:1988 Road Vehicles — Alternators with Regulators — Test Methods and General Requirements 3 Terms and Definitions For the purpose of this document, the terms and definitions given in GB/T 21437.1 apply. 4 Test Procedure 4.1 General These tests for measuring the transient emission on supply lines and the immunity of devices against such transients are called “bench tests”, made in the laboratory. The methods, some of which require the use of the artificial network, will provide comparable results between laboratories. They will also give the basis for the development of devices and systems, and may be used during the production phase (see Annex B). A bench test method for the evaluation of the immunity of a device against supply line transients may be performed by means of a test pulse generator; this may not cover all types of transients which can occur in a vehicle. Therefore, the test pulses described in 5.6 are characteristic of typical pulses. In special cases, it could be necessary to apply additional test pulses. However, some pulses may be omitted if a device, depending on its function or its connection, is not influenced by comparable transients in the vehicle. It is the vehicle manufacturer's responsibility to define the test pulses required for a specific device. Unless otherwise specified, a tolerance of ±10% applies to all variables used. 4.2 Test temperature and test voltage The ambient temperature during the test shall be (23 ± 5)℃. The test voltages shall be according to Table 1 unless other values are agreed upon by the users of this part, in which case such values shall be documented in test reports. Table 1 Test Voltages Test voltage 12 V system (V) 24 V system (V) UA 13.5±0.5 27±1 UB 12±0.2 24±0.4 Note 1: UA is the test voltage when the generator is running. Note 2: UB is the test voltage for battery operation. 4.3 Voltage transient emissions test This subclause specifies a test procedure for evaluating the automotive electrical and electronic components of the device under test (DUT), considered a potential source of conducted disturbances, for conducted emissions of transients along the battery-fed or switched supply lines. Care shall be taken to ensure that the surrounding electromagnetic environment does not interfere with the measurement set-up. Voltage transients from the disturbance source, the DUT, are measured using the artificial network to standardize the impedance loading on the DUT (see 5.1). The disturbance source is connected via the artificial network to the shunt resistor, Rs (see 5.2), the switch, S (see 5.3), and the power supply (see 5.4), as shown in Figure 1 a) or b). All wiring connections between artificial network, switch, and the DUT shall be spaced 500+10 mm above the metal ground plane. The cable sizes shall be chosen in accordance with the real situation in the vehicle, i.e. the wiring shall be capable of handling the operating current of the DUT, and as agreed between vehicle manufacturer and supplier. Dimensions in millimeters a) Slow pulses (millisecond range or slower) b) Fast pulses (nanosecond-to-microsecond range) 1 — oscilloscope or equivalent; 2 — voltage probe; 3 — artificial network; 4 — DUT (source of transient); 5 — ground plane; 6 — power supply; 7 — Ground connection; length < 100 mm. For A, B, P, see Figure 3. Figure 1 Transient Emission Test Set-up If no requirements are specified in the test plan, then the DUT shall be placed on a non-conductive material 500+10 mm above the ground plane. The disturbance voltage shall be measured as close to the DUT terminals as possible [see Figure 1 a) or b], using a voltage probe (see 5.5.2) and an oscilloscope (see 5.5.1) or waveform acquisition equipment (see 5.5.3). Repetitive transients shall be measured with the switch S closed. If the transient is caused by a supply disconnection, measurement shall be started at the moment of opening switch S. For evaluation and values, see Annex C. DUT operating conditions of particular interest in the measurements are the turn on, the turn off, and the exercising of the various operating modes of the DUT. The exact operating conditions of the DUT shall be specified in the test plan. The sampling rate and trigger level shall be selected to capture a waveform displaying the complete duration of the transient, with sufficient resolution to display the highest positive and negative portions of the transient. Utilising the proper sampling rate and trigger level, the voltage amplitude shall be recorded by actuating the DUT according to the test plan. Other transient parameters, such as rise time, fall time and transient duration, may also be recorded. Unless otherwise specified, ten waveform acquisitions are required. Only those waveforms with the highest positive and negative amplitude (with their associated parameters) shall be recorded. The measured transient shall be evaluated according to Annex C. All pertinent information and test results shall be reported. If required per the test plan, include transient evaluation results with respect to the performance objective as specified in the test plan.

Contents of GB/T 21437.2-2008

Foreword II 1 Scope 2 Normative References 3 Terms and Definitions 4 Test Procedure 5 Test Instrument Description and Specifications Annex A (Normative) Failure Mode Severity Classification Annex B (Informative) General Technique for Improving Device Electromagnetic Compatibility Annex C (Normative) Transient Emissions Evaluation — Voltage Waveform Annex D (Normative) Test Pulse Generator Verification Procedure Annex E (Informative) Determination of Pulse Generator’s Energy Capability Annex F (Informative) Origin of Transients in Road Vehicle Electrical Systems