Non-intrusive measurements
The purpose of this test is to confirm the operation of high-frequency and fast switching components within Electric Vehicle (EV) and hybrid systems using non-intrusive Coil On Plug (COP) and Signal Probe measurements.
High Voltage (HV) electrical systems have high voltage cabling, stored electrical energy, retained hazardous voltages, and the potential to affect medical devices.
Risk of damage to equipment and property, risk of electric shock, personal injury, or death, and risk of explosion and fire.
- Read carefully and understand the hazards and risks described above.
- Only work on HV systems if you are a qualified technician, have received appropriate type-specific training from a qualified electrician, and hold valid accreditation.
- Do not work with HV systems if you have been fitted with a pacemaker or other electronic medical devices.
- Always refer to the vehicle manufacturer’s information sources to identify the actions you must take to prevent danger.
- Use equipment and accessories in accordance with their safety guides.
- Always wear appropriate Personal Protective Equipment.
How to perform the test
- Do not proceed with the test if any parts of the HV system or its components are stripped or exposed.
- Connect the COP and Signal Probe to PicoScope Channel A.
- Minimize the help page. You will see that PicoScope has displayed an example waveform and is preset to capture your waveform.
- Use the vehicle controls to activate the system or component of interest.
- Start the scope to see live data.
- Safely manoeuvre the COP and Signal Probe and place it in position on or near the system or component of interest.
- Adjust Channel A input range as required, if the waveform is too large or small.
- With your waveforms on screen stop the scope.
- Use the Waveform Buffer, Zoom and Measurements tools to examine your waveform.
Further guidance
In the example above, the COP Signal Probe detects the oscillating AC current (charge) in the circuit between the EVSE and the On Board Charger (OBC), before it is rectified to the DC voltage and current used to recharge the High Voltage (HV) battery. As such, the COP and Signal Probe can provide a safe and convenient quick check method for confirming the delivery of charge from the EVSE to the vehicle.
The COP and Signal Probe can be used to confirm the presence of activity in other circuits with high frequency or switching voltage characteristics.
When measured with the COP and Signal Probe, the absence of the waveform does not confirm that a voltage or current is not present (it might be that the components or cabling are so well shielded that the probe is unable to detect them); the COP and Signal Probes can only be used to confirm that a voltage or current is present.
The COP and Signal Probe cannot detect constant DC voltages or currents, whether they are within HV components or otherwise.
Always ensure that the COP and Signal Probe and its connection lead are not used in the presence of exposed HV circuits, components or systems and are kept clear from rotating components (whether moving or not).
Disclaimer
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
