Abstract: A method of monitoring the health of a semiconductor power electronic switch such as an insulated gate bipolar transistor (IGBT) is provided. The method having the steps of: measuring one or more parameters selected from the group consisting of: a rate of change of voltage ( dV dt ) across the switch; a rate of change of current ( di dt ) through the switch, a charge present on a gate of the switch (QG), a peak overshoot voltage (VPO) across the switch, and a peak overshoot or reverse recovery current (IRR) through the switch; and estimating the health of the switch based on the measured parameter(s).

Abstract: A method of assessing a condition of a multi-phase power system comprises the steps of: acquiring a voltage signal and a current signal for each phase of the multi-phase power system; calculating a product of the voltage signal for each phase of the multi-phase power system with one of the current signals such that the product is between a voltage signal for one phase and a current signal for a different phase for at least two of the products; summing the calculated products; and identifying the possible existence of a fault in the multi-phase power system based on a frequency analysis of the summed calculated products.

Abstract: A method of open-switch fault detection in a two-level voltage source power converter comprises the steps of: i. acquiring the waveforms of three-phase alternating current of the two-level voltage source power converter; ii. calculating at least a first time derivative of each acquired waveform; and iii. using the at least first time derivatives to determine whether an open-switch fault is present in the two-level voltage source power converter.

Abstract: A method of monitoring the health of a semiconductor power electronic switch such as an insulated gate bipolar transistor (IGBT) is provided. The method having the steps of: measuring one or more parameters selected from the group consisting of: a rate of change of voltage ( dV dt ) across the switch; a rate of change of current ( di dt ) through the switch, a charge present on a gate of the switch (QG), a peak overshoot voltage (VPO) across the switch, and a peak overshoot or reverse recovery current (IRR) through the switch; and estimating the health of the switch based on the measured parameter(s).

Abstract: A method of controlling an inverter, in which the inverter includes a single-phase inverter arrangement comprising a complementary pair of power switches, comprises the steps of: controlling the complementary pair of power switches with a modulating signal to output an AC signal; judging which of the power switches in the complementary pair of power switches is at a higher temperature; determining the magnitude and sign of a DC offset signal to apply to the modulating signal to reduce the total current in the power switch judged to be at the higher temperature; and applying the DC offset signal to the modulating signal.

Abstract: A method of open-switch fault detection in a two-level voltage source power converter comprises the steps of: i. acquiring the waveforms of three-phase alternating current of the two-level voltage source power converter; ii. calculating at least a first time derivative of each acquired waveform; and iii. using the at least first time derivatives to determine whether an open-switch fault is present in the two-level voltage source power converter.

Abstract: A method of assessing a condition of a multi-phase power system comprises the steps of: acquiring a voltage signal and a current signal for each phase of the multi-phase power system; calculating a product of the voltage signal for each phase of the multi-phase power system with one of the current signals such that the product is between a voltage signal for one phase and a current signal for a different phase for at least two of the products; summing the calculated products; and identifying the possible existence of a fault in the multi-phase power system based on a frequency analysis of the summed calculated products.