Alma Automotive provides electrified test cells and its expertise to offer testing services dedicated to electric powertrains. Our test engineers are ready to supervise the tests and create accurate reports at the end of each one, following the customers in every step.

The company has developed a model capable to perfectly simulate the battery pack, starting from the characterization of the cells used or supposed to be used. The system can emulate the electrical and thermal behavior of the device under test. Having the ability to drive power electronics from several suppliers, our system is very flexible and accurate. The common 600V DC bus is used to drive a 200kW battery emulator up to 1050V.

The electric machine to be used as a dynamometer is chosen according to the specific needs of the test: this can be supplied directly from the Borghi&Saveri catalog or purchased ad hoc from our selected suppliers.

Various tests can be performed for the characterization of the electric powertrain, including:

• Performance verification of the electric motor in specific operating points and in regeneration/brake mode
• Motor electrical check and Back EMF (before and after the test)
• Performance characterization of the electric motor in various operating modes (locked rotor, regeneration, max torque)
• Endurance, duty cycle and speed test
• Complete inverter calibration

Each test cell is equipped with an acquisition system based on the National Instruments platform, featured with temperature, pressure and accelerometer sensors. The test management system can directly or remotely control every component of the test cell, such as ventilation, power supplies, safety systems and it can digitize any type of test cell transducer.

Thanks to our custom-made thermal management system, we are able to simulate and reproduce the thermal management of the electric motor and inverter. We are able to perform motor and inverter tests by managing the coolant temperature in real time, emulating the temperature profile that would actually occur in the driving cycle or by testing the components at a desired temperature.

The system installed in the test room allows to the mechanical characterization of the system, by measuring:

• Torque and cogging torque
• Speed
• Vibrations
• Temperatures
• Flow rates and pressures (H2O/Glycol cooling system)

Drag tests can be conducted to measure mechanical losses and we are able to electrically characterize the system under test, using precision power analyzers.

• Accurate measures of efficiency
• AC/DC Current and Voltage measurement
• Motor winding resistance

We can also supply our Predictive Maintenance tool to determine deviations from healthy conditions of the device under test in working conditions.
The A.I. based system uses input data to estimate expected indicators levels (plant model) and then compares them with actual indicators intensities. The approach can be extended to estimate the remaining useful life or optimal maintenance intervals.