Development and quality protection for electric powered vehicles requires comprehensive tests of each component including areas such as energy storage, traction-inverter and the electric motor. Beside the test of all of these components in combination on an e-motor test bench with a high voltage battery, exclusive testing of the traction inverter (PIM) has high importance. For that, Kratzer Automation has developed the testbenches of the DrvHIL series:
Test Benches consisting of the following key components:
The e-motor emulator is replaced by a passive load (inductance cabinet). This test setup is particularly suitable for end-of-line testing and cost-efficient functional test benches. The operating point is set by the rotor sensor emulator, the DUT pulses against the passive inductance cabinet.
The test bench allows flexible testing of different traction inverters. Unlike e-motor test benches, no mechanical setup of the electric motor is necessary. The occurrence and associated problems of critical speeds and mechanical resonances are eliminated. Since there is no mechanical energy in the system, safe test conditions prevail. In the event of a fault, the electrical energy is quickly dissipated into the mains.
Fault conditions that are difficult to implement on a e-motor test bench can easily be reproduced on the DrvHIL test benches:
Either predefined, integrated motor models or external, customer-specific models can be used. A proven solution based on FPGA boards is available for this purpose. The customer can implement his own models via MATLAB/Simulink. The output vector of the motor model is transmitted synchronously with 1MHz sampling frequency to the power electronics.
Limit values and model parameters are configured in the PAtools TX automation system. The automation system controls all sub-systems including data acquisition and online evaluation. Typical tests are function tests, efficiency tests, endurance runs and the retracing of driving profiles.