Claims
- 1. A circuit arrangement operable under control of a master control system to provide adaptive overload protection for power semiconductor switches with anti-parallel free-running diodes in a power supply system, comprising:
sensors for continuously monitoring at least two directly measurable operating parameters of at least one of said semiconductor switches and said power supply system; a data storage memory for storing correction factors in the form of characteristic curve fields and for storing baseline power loss values measured in a defined operating mode of the power supply system; a means for determining applicable correction factors based on current values of said directly measurable operating parameters and based on said characteristic curve fields; a multiplication stage for multiplying the baseline power losses with the applicable correction factors to determine an amount of power lost in the semiconductor switches; a means for determining a junction temperature of the semiconductor switches based on said amount of lost power, using a theoretical thermal model of said semiconductor switches; a comparator means for comparing said junction temperature to a maximum permissible temperature; and a means for transmitting a result of said comparison to the master control system so that operating mode parameters of the power supply system can be adjusted and an emergency shut-down can be prevented in a case where said comparator means indicates a thermal overload condition.
- 2. A circuit arrangement according to claim 1, wherein said parameters include:
a temperature of at least one p-n junction of said switches; a temperature of at least one heat sink; timing frequencies of said switches; at least one intermediate circuit voltage for said switches; an output current; an output polarity; and a duty cycle of said switches.
- 3. A circuit arrangement according to claim 1, wherein said adaptive power shut-down threshold is calculated based on a temperature simulation of said circuit arrangement.
- 4. A circuit arrangement according to claim 2, wherein said operating parameters are digitized and processed by a digital signal processing system.
- 5. A circuit arrangement according to claim 4, further including:
a digital interface; said digital interface capable of communicating said operating parameters, whereby said operating parameters provide individual evaluation of: operation of said circuit arrangement; actual utilization limits of said circuit arrangement; and available power reserves of said circuit arrangement.
- 6. A power circuit overload protection device comprising:
at least one power semiconductor switch; a compensator located in close proximity to said power circuit; corrective factors produced by said compensator from measurements of operational parameters of said power circuit; dynamic overload thresholds for said at least one power semiconductor switch produced by said compensator and based on said corrective factors; and said dynamic overload thresholds are usable by a controller to optimally drive said power circuit to avoid component temperature overload.
- 7. A power circuit overload protection device according to claim 6, wherein:
said operational parameters include: a temperature of a p-n junction of said at least one power semiconductor switch; a temperature of at least one heat sink; timing frequencies of said at least one power semiconductor switch; at least one intermediate circuit voltage of said at least one power semiconductor switch; an output current; an output polarity; and a duty cycle of said at least one power semiconductor switch.
- 8. A power circuit overload protection device according to claim 6, wherein:
said at least one power semiconductor switch include at least one of an IGBT and MOSFET switch; and said at least one power semiconductor switch having an associated free-running diode.
- 9. A power circuit overload protection device according to claim 6, wherein said dynamic overload thresholds are effective to determine a reserve load capacity for said power circuit.
- 10. A power circuit overload protection device according to claim 6, wherein said dynamic overload thresholds are effective to enable a controller to modify a drive profile to prevent thermal overload.
- 11. A power circuit overload protection device comprising:
a characteristics field containing compensated real-time values of operational parameters of said power circuit; said characteristics field effective to provide dynamic overload thresholds for components of said power circuit; and said dynamic overload thresholds are compared to thermal model thresholds for said components, whereby dynamic thermal overload protection is provided for said components in said power circuit.
- 12. A method for providing dynamic thermal overload protection for a power circuit component, comprising the steps:
measuring operational parameter values of said power circuit component; modifying said operational parameter values to provide compensated values; multiplying said compensated values associated with power losses to provide a per switch measure of power losses; multiplying said compensated values associated with switching losses to provide a per switch measure of switching losses; combining said per switch measure of power losses with said per switch measure of switching losses to provide a total load of said power circuit component; comparing said total load with a maximum load for said power circuit component to provide a load capacity; and communicating said load capacity to a controller, whereby said power circuit component can be driven to prevent thermal overload.
- 13. A method for providing dynamic thermal overload protection for a power circuit component according to claim 12, wherein:
said operational parameters include:
a temperature of at least one p-n junction of said power circuit component; a temperature of at least one heat sink; timing frequencies of said power circuit component; at least one intermediate circuit voltage of said power circuit component; an output current; an output polarity; and a duty cycle of said power circuit component.
Priority Claims (1)
Number |
Date |
Country |
Kind |
198 24 064 |
May 1998 |
DE |
|
Parent Case Info
[0001] This application is a continuation-in-part of U.S. Ser. No. 09/320,871, filed May 27, 1999.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09320871 |
May 1999 |
US |
Child |
10411875 |
Apr 2003 |
US |