Overview
ISO/TS 7637-4:2020 - Road vehicles - Electrical disturbance by conduction and coupling - Part 4 - specifies laboratory (bench) test methods for evaluating conducted electrical transients along shielded high‑voltage supply lines. It applies to road vehicles with isolated high‑voltage systems from 60 V d.c. up to 1 500 V d.c., for example BEV, HEV and PHEV. The document defines measurement and injection procedures, recommended test‑setups and instrumentation to assess both transient emission and immunity of high‑voltage vehicle equipment.
Key topics and technical requirements
- Scope: applicability to equipment on vehicles with an isolated high‑voltage power supply (60–1 500 V d.c.).
- Test types:
- Emission tests - measure transients generated by a device under test (DUT) on HV supply lines (line‑to‑line and line‑to‑ground).
- Immunity tests - apply standard transient waveforms to the DUT to verify functional performance.
- Disturbance waveforms:
- Pulse A - pulsed sinusoidal disturbances (high‑frequency ringing from fast switching).
- Pulse B - low‑frequency sinusoidal disturbances (harmonics or motor‑generated waves).
- Test setup essentials:
- Use a High Voltage Artificial Network (HV‑AN) to standardize impedance loading.
- Ground plane requirements: minimum 0.5 mm thick copper/brass/galvanized steel; default dimensions and placement rules are provided.
- Typical default cable length: 500 mm; ground lead default: 200 ± 50 mm; DUT positioned ~50 ± 5 mm above ground plane on a low‑permittivity support (ε ≤ 1.4).
- Measurements taken close to DUT terminals with high‑voltage differential probes and waveform acquisition equipment.
- Documentation and limits:
- Record voltage amplitude, rise/fall times and transient duration; evaluate results per Annex B.
- Bench tests are reproducible across laboratories but are representative - vehicle manufacturers may require extra pulses or omit pulses not relevant to a specific DUT.
Applications and users
ISO/TS 7637-4 is intended for:
- Automotive OEMs and vehicle manufacturers defining EMC test programs for high‑voltage systems.
- Tier‑1 suppliers and component designers (inverters, DC‑DC converters, battery management systems, HV harnesses) performing design validation.
- Independent test laboratories performing emission and immunity bench tests.
- Quality, validation and safety engineers integrating HV equipment into BEV/HEV/PHEV platforms.
Practical benefits include comparable inter‑lab results, early detection of susceptibility to switching transients, and guidance for grounding/shielding and harness design.
Related standards
- ISO 7637 series (general guidance on conduction and coupling transients)
- ISO 7637‑1 (definitions and general considerations) - normative reference within the specification
Keywords: ISO/TS 7637-4:2020, high voltage supply lines, electrical transient, Pulse A, Pulse B, HV‑AN, bench tests, automotive EMC, BEV, HEV, PHEV.
Open preview (PDF)Road Vehicles — Electrical disturbance by conduction and coupling — Part 4: Electrical transient conduction along shielded high voltage supply lines only