An inrush current protection circuit for a polyphase alternating current power system may include a plurality of current limiting resistors, each of which is electrically coupled in series between a respective one of a plurality of phases of the polyphase alternating current power source and a respective input of a polyphase transformer rectifier unit. The circuit may also include a plurality of power switches, each of which is electrically coupled in parallel with a respective one of the current limiting resistors, such that when each of the power switches is closed, essentially no electrical current flows through the respective current limiting resistor. The circuit may also include a power switch controller configured to control each of the power switches to be open such that an inrush current passes through the respective current limiting resistor rather than the power switch, and to be closed after a time delay has passed.