Masahiro Kimata

Power loss and junction temperature analysis of power semiconductor devices

A new developed electro-thermal calculation method is implemented to estimate the power loss and working temperature of IGBT devices. Based on the measurement of IGBT characteristics, the exact estimation of power loss considering the junction temperature is introduced. Then the thermal network is used to calculate the working temperature. The comparison between experiment and calculation results shows that this method is effective as a designing step with only the time domain voltage and current data obtained from simulation results.

New switching method for single-phase AC to DC converter

A new switching method, called the simple partial switching (SPS) method, is proposed for a single-phase AC to DC power converter. The control device switches once in every half cycle of an AC commercial power source by this SPS method. The optimal switching timing is decided by the input power factor and by the odd order harmonic estimation function of the input current. The estimation function is defined as the harmonics ratio compared with the IEC standard concerning the absolute value.<<ETX>>

Smart IGBT model and its application for power converter design

This paper proposes a novel IGBT model suitable for analyzing the static and dynamic switching characteristics of IGBT modules, which are widely used in power converter circuits. This model is a subcircuit model derived from the basic IGBT equivalent circuit, and can be implemented in the circuit simulator SPICE without modifying the simulator codes nor using user-defined subroutines. Model parameters are easily extracted from measured electrical characteristics of IGBT modules. The validity of this model is confirmed by experimental results. Some simulation results are also presented to indicate the availability of this IGBT model for accurately estimating the performance of power converters and for designing their robust snubber protection circuits.<<ETX>>

Research on the power loss and junction temperature of power semiconductor devices for inverter

A new calculation method to estimate the power loss and the working temperature of IGBT and diode devices in an inverter is presented. This method is based on the measurement data of the IGBTs transient and steady state characteristics under different conditions and the thermal equivalent network model of the actual system. Finally, an experiment of a drive system including an inverter and a permanent magnet synchronous motor was done. The result shows that the calculation program is very effective for the thermal design of inverters.

Junction temperature analysis of IGBT devices

The junction temperature of IGBT is the key factors that could influence the whole systems reliability and efficiency. An electro-thermal method was implemented to estimate the junction temperature of IGBT devices in this paper. The junction temperature of power devices was found out based on the power losses of IGBT devices and the transient thermal impedance model. The comparison between experiment using a 50 A/600 V IGBT module and calculation results shows that this method is effective.

Transient junction temperature calculation method for large capacity GTO

Based on the dynamic thermal response curve by experiments, a new concept of multipartite linear time intervals is presented to acquire the transient heat transfer model of a GTO. The validity of this modeling strategy is also investigated with regard to different kinds of GTO devices. Furthermore, a steepest descent algorithm is posed to accurately adjust the parameters of the high-order equivalent heat transfer network of GTO. Finally, the transient junction temperature calculation method is given considering the adiabatic behavior of GTO during its switching process, which is practicably preferable to the routine method used in developing a general engineering system and can provide a more detailed reference basis for design.

Investigation on the analysis software for switching characteristics of large capacity GTO

Owing to the lack of sufficient power loss data of different working conditions for GTO in the technical manuals of many companies, the manufactures and the consumers often encounter difficulties in selecting suitable devices for the design of practicable application systems. The authors have constructed a large capacity test circuit to carry out experimental investigation on the loss characteristics of GTO under various arrangements of circuit parameters. Then the powerful ANN (artificial neural network) and the BP (backpropagation) algorithm are introduced to build up the quantitative relations between the varied circuit parameters and the recorded loss data so that power loss tables can be created. In addition, the paper poses a revised steepest algorithm to fit the high-order heat transfer model of GTO according to its transient thermal behavior. All the algorithms are integrated in a software package based on which to carry through power loss analysis and output the transient and average junction temperature data or curves.