The present disclosure relates to a method for estimating parameters of a junction of a power semi-conductor element comprising: •—Detecting at least one stable on-line operating condition through measurements (2, 3, 4) of Von, Ion, Tc on a semi-conductor module (1) where Ion is a current for which the on-state voltage Von of the semi-conductor is sensitive to the temperature and Tc is the temperature of the casing of said semi-conductor element; •—Measuring and storing at least one parameter set Von, Ion, Tc of said at least one stable operating condition; •—in a calculating unit (52), providing calculations for minimizing the error between a junction temperature estimation Tj of an electrical model Tj=F(Von, Ion, θelec) comprising a first set of unknown parameters θelec and another junction temperature estimation Tjmod of a loss/thermal model Tj=G(lon, Tc, θ mod) comprising a second set of unknown parameters θ mod and obtaining at least one set of parameters θelec and at least one parameter θ mod providing minimization of said error; •—providing the calculated value of Tj with at least one of the calculated parameters sets θelec and/or θ mod and the measured Von, Ion, Tc; •—Storing the at least one parameters set θelec and/or θ mod and/or Tj.

A power supply circuit for measuring transient thermal resistances includes an inverter circuit provided on a primary side of a transformer and controlled by a PWM signal, a rectifier circuit provided on a secondary side of the transformer and including a DC reactor, and a control circuit controlling the PWM signal so as to output a pulsed output current from the rectifier circuit to a semiconductor device to be measured. The control circuit sets a first PWM frequency at rising timing of the output current, and sets a second PWM frequency when a predetermined time t1 elapses from the rising timing of the output current. The control circuit sets the first PWM frequency higher than the second PWM frequency.

The present invention provides a system and method for measuring intermittent operating life (IOL) of a GaN-based device under test (DUT) is provided. The system is operable in a stressing mode, a cooling mode and a measure mode. A power regulation approach is adopted to ensure that DUT of the same thermal resistance have same temperature increase during the IOL test. The present invention eliminates the influence caused by parasitic parameters of testing circuits and the inconsistency of threshold voltage and drain-source resistance of the device itself. Through power regulation, it is the junction temperature of the device, not the housing temperature of the device, being directly controlled. Therefore, higher measurement accuracy can be achieved.

A method analyzes an operation of a power semiconductor device. The method includes: providing a set of reference voltages of the device and a set of corresponding reference currents; measuring, within a predetermined time-interval, Nframe on-state voltages and Nframe corresponding on-state currents of the device to obtain Nframe measurement points, Nframe being an integer number equal to or greater than 2; adapting the set of reference voltages by carrying out a least squares fit to the Nframe measurement points; and using the adapted set of reference voltages to analyze the operation of the power semiconductor device.

Systems and methods for estimating electrical component degradation include a processor programmed to: compute a cumulative degradation value for an electrical system component of an electrical system based on an operating parameter of the electrical system component; and to compute a corrosion compensated cumulative degradation value for the electrical system component based on the cumulative degradation value and a corrosion rating of the electrical system.

Provided is a test method comprising: preparing a plurality of groups for setting, each of which has a plurality of semiconductor devices for setting, and assigning an inspection voltage to each of the respective plurality of groups for setting; performing first testing by applying the assigned inspection voltage to the semiconductor devices for setting, and testing, at a first temperature, the plurality of semiconductor devices for setting included in each of the plurality of groups for setting; performing second testing by testing, at a second temperature different from the first temperature, a semiconductor device for setting having been determined as being non-defective and by detecting a breakdown voltage at which the semiconductor device for setting is broken; acquiring a relationship between the inspection voltage and the breakdown voltage; and setting an applied voltage used when testing a semiconductor device under test at the first temperature, based on the acquired relationship.

The invention discloses a method and a system for characterizing IGBT module aging based on Miner theory, including first establishing a life prediction model with a junction temperature fluctuation T.sub.jm and an average junction temperature ΔT.sub.j as inputs; then measuring a chip junction temperature data of an IGBT module; recording the junction temperature fluctuation T.sub.jm and the average junction temperature ΔT.sub.j of each power cycle; performing one life prediction in each cycle; and taking a reciprocal of a predicted life corresponding to each cycle and adding them to obtain an aging characteristic parameter D of the IGBT module. The invention may more suitably characterize the aging degree of the IGBT, and has the advantages of monotonically increasing change trend and high resolution.

The disclosure relates to a junction temperature calculation method for a power conversion module. The power conversion module includes a first switching device. The junction temperature calculation method includes: correcting a conduction loss of the first switching device, where the correction of the conduction loss is based on at least a first correction coefficient K.sub.1, and the first correction coefficient K.sub.1 is associated with a modulation ratio of the power conversion module; and calculating a junction temperature of the first switching device as a junction temperature of the power conversion module, where the calculation of the junction temperature of the first switching device is based on at least the corrected conduction loss. The disclosure also relates to a junction temperature calculation device for a power conversion module, a computer-readable storage medium, and a vehicle. In the junction temperature calculation solution proposed by the disclosure, the conduction loss and a switching loss of the switching device are corrected based on the correction coefficient according to factors such as the modulation ratio and an alternating-current frequency, thereby improving the calculation precision of the junction temperature of the power conversion module.

A front-end device for monitoring operation of an associated electric power device with semiconductor power switches generating a power output, e.g. a three-phase power output. The front-end device has input terminals arranged for connection to the electric phase(s) of the power output of the associated electric power device, and an electric circuit connected to the input terminals and connected to at set of output terminals. The electric circuit has a passive interconnection comprising electric semiconductor switches and diodes. The electric circuit serves to electrically block any high voltage component from the input terminals from reaching the output terminals, while allowing an on-state voltage of at least one semiconductor power switch in the associated electric power device to pass to the at least two output terminals. The front-end allows low voltage equipment to be connected to its output terminals for determining an on-state voltage of switches of the electric power device. Especially, embodiments with self-powered reference voltage circuits provided by zener diodes allow compact low cost versions for use in e.g. portable test equipment or as part of permanently installed health condition monitoring of power devices. The front-end device can be used as a simple and low cost solution for non-invasive health condition monitoring of power devices, e.g. power converters in such as power electric generation system or electric vehicles. Such monitoring allows predictive maintenance to be performed to avoid any faults in the power device that may cause permanent damages.

A method analyzes an operation of a power semiconductor device. The method includes: providing a set of reference voltages of the power semiconductor device and a set of corresponding reference currents; measuring an on-state voltage and a corresponding on-state current of the power semiconductor device to obtain a measurement point; adapting the set of reference voltages by adapting two of the set of reference voltages lying closest to the measurement point by extrapolating the measurement point; and using the adapted set of reference voltages to analyze the operation of the power semiconductor device. The extrapolation is based on a predefined reference increment current and a predefined reference increment voltage.