Electric drive motors are controlled by inverters, which are designed as power electronics including control logic for electric motors.
Inverters convert the 3-phase alternating voltage of the generator (i.e. the electric motor during braking) into a DC voltage for charging the battery. Similarly, when the electric motor is driven, the DC voltage of the battery is converted into a 3-phase AC voltage.
Test benches for inverters are an elementary component of electromobility. Function tests, quality and endurance tests with or without environmental simulation (e.g. climate) as well as end-of-line test systems for different performance classes of inverters belong to the task spectrum.
Function Test Inverter
The core task in the functional test of the inverter is to simulate the system components such as the energy source (battery) and the load (electric motor) and make them available for the functional test of the component.
The simulation is carried out with original loads (stators) or with passive or electronic equivalent loads, which in turn are defined by the phase outputs of the DUT (3/6-phase).
By replacing the original loads with an electric machine emulator and the energy source with a battery emulator, real load scenarios can be simulated. An additional special feature when handling inverters is the provision of a coolant supply on the test specimen, as this must be actively tempered.
In combination with wear-free contacting, suitable for production, and coupled environmental simulation, this results in highly complex overall test systems.
End-of-Line Test (EOL) for Electric Motors
In its test environment, the end-of-line test realizes all necessary simulations, for example the energy source (battery) or the consuming electric motor as a load.
The functions are tested automatically. The test object is also automatically delivered and contacted.
Once the function test has been completed, the DUT is transferred back to the transport system for further processing. The necessary communication to the DUT is carried out via interfaces on the function test system.
The residual bus simulations required for the automotive bus systems (e.g. CAN-FD, LIN, FlexRay) are implemented by us as an end-of-line system according to the requirements of the function test system.
Run-in Test for Inverters
Run-in systems perform a reduced function test for inverters. This reduced function test corresponds to the function test, but with the focus on guaranteeing and monitoring general functionality.
The run-in system simulates a battery or electric motor. The simulation of the vehicle environment is also performed using automotive bus systems.
An essential component of the run-in systems is an environmental simulation by a climatic chamber. This makes it possible to include any climate profile in the test. In connection with a production-suited, wear-free contacting with coupled environmental simulation via the climate chamber, we offer you a comprehensive test system.