With the widespread application of press-pack devices in fields such as high-voltage direct current (HVDC) transmission

the double-sided cooling characteristics pose new challenges to traditional thermal resistance measurement methods. Existing methods suffer from complex procedures and significant uncertainties in measured results. To address these issues

this paper proposes a novel thermal resistance measurement method for press-pack devices based on bidirectional heat flows. For the first time

the thermal resistance ratio between the two sides of the device is used as a direct measure. Based on bidirectional heat flow conditions

constraint equations for the thermal resistance network are constructed

enabling effective decoupling of the thermal resistances on both sides

which simplifies the measurement process and improves the accuracy of the results. On this basis

a thermal resistance measurement system based on bidirectional heat flows is developed and applied to the thermal resistance measurement of press-pack integrated gate- commutated thyristor (IGCT) devices. The experimental results show good agreement with theoretical and simulation results

with a relative error of less than 2%. This method is applicable to measuring the thermal resistance of all full-wafer press-pack power devices and provides technical support for the thermal design of press-pack devices.