As powertrain electrification moves forward, tool providers are stepping up to help engineers improve efficiency. National Instruments has enhanced its hardware-in-the-loop (HIL) technology, partnering with JSOL to create a tool called the JMAG-RT add-on for NI VeriStand.
It gives engineers the same fidelity provided by proven JMAG models from JSOL, a Japanese supplier whose JMAG simulation technology is widely used for electromechanical design. The result is a tool for real-time HIL testing of large electric motors.
Using HIL can reduce spending on field tests for prototype motors. Engineers can run tests in the lab to easily create stimulus profiles and perform data logging and automated HIL testing with real-time electric motor simulation.
“The system helps expand engineers’ test coverage while saving time and money because they now can perform electronic control unit testing without risking damage to expensive prototype motors,” said Takashi Yamada, Manager of Electromagnetic Engineering at JSOL.
In the past, many HIL tools for electric motors couldn’t handle the many subtleties of the large motors used in powertrains. Engineers using these simulations had to sacrifice speed or accuracy/resolution.
“Electric motors are getting larger and running at much higher frequencies, around 200 kHz,” said Nick Keel, NI VeriStand Product Manager at NI. “We’re implementing new FPGA technology that lets us put the entire motor on one FPGA and run the tests in real time. When developers can very closely replicate the full electric motor, they can tune the powertrain very closely using HIL.”
NI has long worked closely with FPGA supplier Xilinx Inc. to get hardware that can be programmed for various tasks. NI’s latest VeriStand hardware implements larger FPGAs not yet being widely shipped. That lets motor developers test electronics and software before physical motors are ready.
“You can run tests on your control algorithms before the motor is done,” Keel said. “There’s a lot of intellectual property that goes into motor development so it makes a lot of sense to test everything before you get the motor ready as a prototype.”
NI engineers noted that there are many subtleties in electric motors that are difficult to analyze without extensive simulation. These events occur at high speeds, so fast systems are needed to measure the parameters engineers want to examine.
“With power electronics, switching happens very quickly, at rates of 25, 50, and 100 kHz. To capture events with high accuracy, you need to run simulations at 100 to even 1000 times faster,” said Ben Black, System Engineer, Advanced Control & Simulation. “We need to accurately measure the edges of the PWM signal. In the past, simulations couldn’t run fast enough to handle that.”