Power Relay Based Multiple Device Cryogenic Characterization Method and Results

Cryogenic power electronics is a promising technology due to their high efficiency and high power density characteristics. As the key element of power electronic systems, semiconductor performance should be evaluated under cryogenic temperatures. Liquid nitrogen or liquid helium are usually adopted to achieve cryogenic temperatures. Traditionally, only one semiconductor can be evaluated at one time under different temperatures, which is time-consuming and not energy-friendly. To enable multiple-device characterization at one time under different temperatures, a novel power relay based characterization circuit and corresponding control strategy are described. With the aid of the proposed circuit, multiple devices can be characterized by controlling the power relays. The introduced parasitics by the power relays are minimized through paralleling, which has negligible influence on the device under test (DUT). Cryogenic characterization results of the gate driver, power relay, and semiconductors are presented. Both silicon (Si) metal–oxide–semiconductor field-effect transistor (MOSFET) and silicon carbide (SiC) MOSFETs are characterized and their performances are discussed.