Temperature stress test of high-voltage heaters for automotive applications

In order to be able to make a statement about the durability of a heater technology at an early stage of development, a test setup was implemented with media-side conditioning from -40 °C to 90 °C and air-side conditioning to room temperature with low humidity (so-called thermal stress test).

Experimental service

Requirements for the thermal stress test

Compliance with limit values and shutdown in the event of an error are particularly important when developing new products. In this case, the volume flow was set before the start of the test and monitored continuously. Furthermore, inlet, differential and outlet pressures and the temperatures before and after the test specimens were measured and monitored. Since particular attention was paid to the change in the performance of the components due to thermal cycling, measurement and monitoring of the electrical currents (up to 40 A) of the individual heating elements and the electrical voltage (up to 500 V) were used.

Monitoring and measurement variables

Pressure measurement before and after the high-voltage heaters as well as differential pressure measurement of the test items
Temperature measurement of the inlet and outlet temperatures of the individual components as well as the ambient temperature
Individual volume flow measurement under test
Current measurement of the individual heating elements of the test items
Voltage measurement of the test specimens
Measure PWM signal up to 1 kHz
Measurement of the insulation resistance of the DUT