As an example, HIL testing allows for prototype designs of equipment like traction inverters to be evaluated in various battery, load and fault situations, without the need to perform the trials with the inverters installed in dynamometers or the vehicles themselves. HIL testing allows for faster and more cost-effective product development, as relevant components of the drivetrain can be emulated.
It was once much more typical with signal conditioning applications involving high voltage environments, for the most extreme electrical isolation requirements to be seen at the input side of the configuration. The output would then often be tied to a lower voltage control system. However, with the increased applications for hardware in the loop (HIL) testing for vehicle electrification, the high voltage source is often found at the output side of the configuration. Signals are generated by the testing systems to emulate conditions seen within the vehicle, and thus, the effects on the high voltage components that make up the vehicle.
Requirements of Application
Incorporating devices that can handle the requirements for signal conversion, while at the same time electrically isolating all channels, is critical for HIL system design and performance. The emulation of components in highly dynamic systems requires correspondingly fast and precise signal transmission.
The Knick P15000 and A26000 (if bipolar measurements are needed) can transmit signals from emulating model on ground potential and send them to equipment under test on high electrical potential.
High output insulation of 1000 V or more is the decisive characteristic of this solution. The small size and stackability allows the control of stacked systems in reasonably sized cabinets. T90 response time is rated at 70 μs, and the device contains a cutoff frequency specification of 10 kHz. Accuracy is maintained with the conversion from input to output through a gain error of < 0.1 % of the measured value.