A Phase Change Material Integrated Press Pack Power Module With Enhanced Overcurrent Capability for Grid Support—A Study on FRD

The capability of dynamic grid support of a voltage source converter-high voltage direct current (VSC-HVdc) system depends on the maximum allowable current of the converter. This study attempts to increase the capability by overloading the power semiconductor device for a short period of time. Keeping the device temperature low is a major challenge due to the extra loss and small local thermal capacity. This study investigates a solution to increase the transient thermal capacity by making use of the latent heat of a phase change material (PCM). This article presents an integration scheme for a press pack power module, focusing on the fast recovery diode in an IGBT-diode package. Experiment and finite element analysis are used to evaluate the concept and analyze the factors affecting the design. It is shown that as heat is absorbed by the integrated PCM, the device temperature rise during a power surge is effectively tempered, providing a high short-term overcurrent rating of the device and an increased dynamic grid support capability of the VSC-HVdc system.