# US 9,039,279 B2 · System and method for monitoring in real time the operating state of an IGBT device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,279 B2 - Document ID: US9039279B2 - Status: Granted - Kind: B2 - Application number: 13/739,742 - Filed: 2013-01-11 - Published: 2013-07-11 - Granted: 2015-05-26 - Earliest claimed: 2012-01-11 - Assignees: ABB Research Ltd. - Applicants: ABB Research Ltd - Inventors: Vinoth Sundaramoorthy; Alexander Heinemann; Enea Bianda; Franz Zurfluh; Gerold Knapp; Iulian Nistor; Richard Bloch - Web page: https://patentgrep.com/patent/US9039279B2 ## CPC - H10P 74/27: {Structural arrangements therefor} - G01K 7/01: using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) - G01R 31/2619: {for measuring thermal properties thereof} - G01R 31/2642: {Testing semiconductor operation lifetime or reliability, e.g. by accelerated life tests} - H03K 17/18: Modifications for indicating state of switch - G01K 2217/00: Temperature measurement using electric or magnetic components already present in the system to be measured - H03K 2017/0806: {against excessive temperature} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A system and method are provided for monitoring in real time the operating state of an IGBT device, to determine a junction temperature and/or the remaining lifetime of an IGBT device. The system includes a differential unit configured to receive a gate-emitter voltage characteristic of the IGBT device to be measured and to differentiate the gate-emitter voltage characteristic to obtain pulses correlating with edges formed by a Miller plateau phase during a switch-off phase of the IGBT device. The system also includes a timer unit configured to measure the time delay between the obtained pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device, and a junction temperature calculation unit configured to determine at least one of the junction temperature of the IGBT device and/or the remaining lifetime of the IGBT device based on the measured time delay. ## Claims ### Claim 1 A system for determining at least one of a junction temperature and a remaining lifetime of an IGBT device, comprising: a differential unit configured to receive a gate-emitter voltage characteristic of the IGBT device to be measured, and to differentiate the gate-emitter voltage characteristic to obtain pulses correlating with edges formed by a Miller plateau phase during a switch-off phase of the IGBT device; a timer unit configured to measure a time delay between the obtained pulses indicating a start and end of the Miller plateau phase during the switch-off phase of the IGBT device; and a junction temperature calculation unit configured to determine at least one of the junction temperature and the remaining lifetime of the IGBT device based on the measured time delay. ### Claim 2 (depends on 1) The system according to claim 1, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to filter pulses based on a reference switch voltage as a threshold level, and wherein the signal amplitude detection unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 3 (depends on 1) The system according to claim 1, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to compare voltage levels of pulses with a respective reference switch voltage as a threshold level to obtain binary pulse signals, and wherein the signal amplitude detector unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 4 (depends on 3) The system according to claim 3, wherein the comparator unit is configured to apply a hysteresis when comparing the voltage levels of pulses with the respective reference switch voltage as a threshold level to obtain the binary pulse signals. ### Claim 5 (depends on 1) The system according to claim 1, wherein the junction temperature calculation unit is configured to determine the junction temperature of the IGBT device based on the measured time delay and on a collector-emitter voltage of the IGBT device and an IGBT device current. ### Claim 6 (depends on 5) The system according to claim 5, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to filter pulses based on a reference switch voltage as a threshold level, and wherein the signal amplitude detection unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 7 (depends on 5) The system according to claim 5, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to compare voltage levels of pulses with a respective reference switch voltage as a threshold level to obtain binary pulse signals, and wherein the signal amplitude detector unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 8 (depends on 7) The system according to claim 7, wherein the comparator unit is configured to apply a hysteresis when comparing the voltage levels of pulses with the respective reference switch voltage as a threshold level to obtain the binary pulse signals. ### Claim 9 (depends on 5) The system according to claim 5, wherein the junction temperature calculation unit is configured to determine at least one of the junction temperature of the IGBT device and an indication of the remaining lifetime by means of at least one of a look-up table and a mathematical function. ### Claim 10 (depends on 9) The system according to claim 9, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to filter pulses based on a reference switch voltage as a threshold level, and wherein the signal amplitude detection unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 11 (depends on 9) The system according to claim 9, comprising: a signal amplitude detector unit and a comparator unit configured to select the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the comparator unit is configured to compare voltage levels of pulses with a respective reference switch voltage as a threshold level to obtain binary pulse signals, and wherein the signal amplitude detector unit is configured to generate the respective threshold levels based on the amplitudes of the pulses obtained in the differential unit. ### Claim 12 (depends on 11) The system according to claim 11, wherein the comparator unit is configured to apply a hysteresis when comparing the voltage levels of pulses with the respective reference switch voltage as a threshold level to obtain the binary pulse signals. ### Claim 13 A method for determining at least one of a junction temperature and a remaining lifetime of an IGBT device, the method comprising: differentiating a gate-emitter voltage characteristic to obtain pulses correlating with edges formed by a Miller plateau phase during a switch-off phase of the IGBT device; measuring a time delay between the obtained pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device; and determining at least one of the junction temperature and the remaining lifetime of the IGBT device based on the measured time delay. ### Claim 14 (depends on 13) The method according to claim 13, wherein the junction temperature of the IGBT device is further determined based on a collector-emitter voltage and an IGBT device current. ### Claim 15 (depends on 13) The method according to claim 13, wherein at least one of the junction temperature of the IGBT device and an indication of the remaining lifetime is determined by means of at least one of a look-up table and a mathematical function. ### Claim 16 (depends on 13) The method according to claim 13, comprising: selecting the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the selecting of the pulses comprises: filtering pulses based on a reference switch voltage as a threshold level, and generating the respective threshold levels based on the amplitudes of the obtained pulses. ### Claim 17 (depends on 13) The method according to claim 13, comprising: selecting the pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device from other pulses, wherein the selecting of the pulses comprises: comparing voltage levels of pulses with a respective reference switch voltage as a threshold level to obtain binary pulse signals; and generating the respective threshold levels based on the amplitudes of the obtained pulses. ### Claim 18 (depends on 17) The method according to claim 17, comprising: applying a hysteresis when comparing the voltage levels of pulses with the respective reference switch voltage as a threshold level to obtain the binary pulse signals.