In a short space of time, the development of electric vehicles has been significant. This article, written by MK Test Systems Sales Manager Graham Andrews, looks at how EV testing requirements are evolving as a result.
The rapid changes in the EV market
In a short space of time, the development of eVehicles has been significant. Vehicle manufacturers have invested significant money to extend vehicle range, decrease charging times, whilst ensuring batteries are protected to minimise degradation throughout the life of a vehicle.
Most manufacturers started with 400V power infrastructure. This offered an improvement on the earlier EV hybrids which had only small battery packs. More recently some vehicles are using 800V infrastructure which halves charging times. Additionally higher voltage creates lower current, reducing heat. This enables a charge to 80% battery capacity in less than 20 minutes. Currently 800V power infrastructure on a vehicle is much more expensive – but for many manufacturers the benefits outweigh the costs.
With an electrical vehicle, either the voltage or current can be increased to boost power to the battery. If you use more current, the cables must be thicker, and therefore heavier and more expensive. However, by increasing the voltage, cable thickness can be reduced as the electrical resistance is lower.
The impact on vehicle cable testing
More insulation is required for the HV conductors, and lower power density in the motors, caused by thinner wires and greater insulation thickness. Connection resistance of connectors and contact wiring crimps that carry high voltages or high currents need to be tested. Even with a small amount of contact resistance, large currents cause voltage drops that can cause components to heat up. This prevents them from performing to specifications and accelerates connector deterioration. Such problems need to be prevented.
MK Test Systems manufacture a range of test systems which can rapidly test for these issues. We specialise in test and measurement at high voltages and can offer test systems able to measure from 32 test points right up to 256,000 (pins) and beyond. These systems offer highly accurate (4- terminal) kelvin measurement.
Prediction for the future of EV testing requirements
The trend towards higher voltages and currents is likely to continue, especially with the growing EV Aerospace market. Manufacturers are being called upon to further increase the quality of their connectors and harnesses, and to improve mass production testing times.
Our test systems record every measurement, and our software integrates with OPC manufacturing systems to enable the highest possible accuracy and traceability for every vehicle harness and every vehicle receiving the harnesses.