Regeneration current
The purpose of this test is to check High Voltage (HV) battery charging by regeneration when the vehicle is decelerating. Only perform this test where safe access to the HV Direct Current (DC) cables is possible.
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
- Use vehicle manufacturer's data to identify both the brake pedal and accelerator pedal sensor signal circuits and a safely accessible HV DC supply cable leading from the HV battery to the motor inverter.
- Stop the test and do not continue, if there is no safely accessible HV DC supply cable leading from the HV battery to the motor inverter.
- Connect a test lead to PicoScope Channel A and the brake pedal signal circuit.
- Connect a test lead to PicoScope Channel B and the accelerator pedal signal circuit.
- Connect the high amps clamp to PicoScope Channel C and the HV cable leading from the HV battery to the motor inverter.
- Minimize the help page. You will see that PicoScope has displayed an example waveform and is preset to capture your waveform.
- Start the scope to see live data.
- With a passenger operating the PicoScope software and equipment and with a driver observing local driving laws and regulations, carry out a road test.
- With your waveforms on screen stop the scope.
- Use the Waveform Buffer, Zoom and Measurements tools to examine your waveform.
Further guidance
Regenerative braking during deceleration is critical to an EV's ability to extend its range. The range gained strongly depends on the road conditions and the driver's driving style.
The process uses an electric vehicle motor as a generator: a motor (acting as a generator) remains engaged with the drive wheels whilst there is no demand for acceleration so as to turn the kinetic energy of the vehicle into potential energy stored in the battery. The engagement of the motor creates drag on the vehicle and causes it to decelerate, hence the term regenerative braking.
The accelerator pedal and brake pedal sensors and signals in your vehicle may have different characteristics. However, the key point to note is the HV battery and inverter DC circuit current should flow in opposite directions during acceleration and braking.
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.
