TESTING & SAFETY
CURRENT AFFAIRS
Dewetron’s power analysers allow engineers to measure several different parameters with only measurement device
Rafael Ludwig, team leader, product management & application at Dewetron
Rafael Ludwig tells Louise Davis how advanced solutions are stepping up to tackle the test & measurement challenges that electric drivetrains present
T
he e-mobility transition means that existing automotive test & measurement technology providers are having to adapt and evolve their offerings to meet the challenges associated with testing electric drivetrain systems. As Rafael Ludwig, team leader, product management & application engineering at Dewetron, explains, “Electric drivetrains place extreme demands on measurement technology due to fast switching edges, high dv/dt rates and increasing voltage levels.” So, how does the Austrian test & measurement company ensure its solutions are able to meet this new challenge? “We address this with high-bandwidth mixed-signal power analysers that combine up to 10MS/s sampling rates, 5MHz bandwidth, 18-bit resolution and excellent linearity across the full input range,” Ludwig says. “Our systems maintain a constant measurement uncertainty of just 0.03% across a wide frequency
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range, enabling precise waveform capturing even during highly dynamic inverter switching events.” Ludwig adds that signal integrity is further ensured via isolated inputs, short signal paths via distributed data acquisition (DAQ) architectures and synchronised acquisition of electrical and auxiliary signals in one system: “This is especially important for silicon carbide (SiC)-based inverters, where switching frequencies and transient behaviour continue to increase.”
EFFICIENCY DRIVE
Efficiency is one of the most critical KPIs in EV development – because even small losses directly affect vehicle range. Ludwig says: “Our mixed-signal and poly-phase power analysers allow engineers to measure electrical input/output power, torque, speed, temperature, CAN signals and vibration fully synchronised on multiple measurement points with only one measurement device. This enables detailed loss analysis across
the complete drivetrain – covering everything from inverter switching losses, mechanical drivetrain losses, thermal losses under load, to efficiency mapping over speed and torque.” On that last point, Ludwig comments: “A major advantage is our online efficiency mapping, where engineers can visualise efficiency islands in real time during test bench operation. Instead of evaluating only average efficiencies, they gain a cycleby-cycle understanding of transient loss mechanisms, which is becoming increasingly important for Worldwide Harmonised Light Vehicles Test Procedure (WLTP) cycles and real driving profiles.”
TESTING TIMES
Testing electric drivetrains involves electrical, mechanical and thermal data streams: how does Dewetron ensure precise time synchronisation across these domains? “Synchronisation is one of the most underestimated factors in e-drivetrain testing,” notes