State of Health Estimation of Power Converters

• US 20140103937A1
• Filed: 10/16/2012
• Published: 04/17/2014
• Est. Priority Date: 10/16/2012
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah (State of Utah), University of Utah Research Foundation (State of Utah)
• Inventors: Khan, Faisal, Nasrin, Most. Sultana, Alam, Mohammed Khorshed
• Granted Patent: US 9,494,657 B2
• Time in Patent Office: Days
• US Class Current: 324/509
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 31/2621 for testing field effect transistors, i.e. FET's
• CPC Class Codes: G01R 31/2839 using signal generators, power supplies or circuit analysers G01R31/2879 takes precedence; multimeters G01R15/12, network analysers G01R27/28
• CPC Class Codes: G01R 31/327 Testing of circuit interrupters, switches or circuit-breakers
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: G01R 31/64 Testing of capacitors
• CPC Class Codes: G01R 31/72 Testing of electric windings testing of transformers G01R31/62
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

Systems, methods and devices which utilize Spread Spectrum Time Domain Reflectometry (SSTDR) techniques to measure degradation of electronic components are provided. Such measurements may be implemented while the components “live” or otherwise functioning within an overall system. In one embodiment, monitoring a power converter in a high power system is accomplished. In this embodiment, degradation of components within the power converter (e.g. metal-oxide-semiconductor field-effect transistors (MOSFETs), capacitors, insulated-gate bipolar transistors (IGBTs), and the like) may be monitored by processing data from reflections of an SSTDR signal to determine changes in impedance, capacitance, or any other changes that may be characteristic of components degrading. For example, an aging MOSFET may experience an increase of drain to source resistance which adds additional resistance to a current path within a power converter. Such a change is able to be analyzed monitored upon processing the reflected test signals.

Claims

1. A method for estimating the state of health of an electronic component, said method comprising:

placing the electronic component under test while said electronic component is in a live working condition;

propagating a test signal into the electronic component, said test signal configured to be non-interfering with the functionality of the electronic component;

receiving reflections of the propagated test signal from the electronic component at a testing device; and

processing the reflected signal to determine at least one performance-degradation characteristic of the electronic component.

2. The method of claim 1 wherein the electronic component is a power converter.

3. The method of claim 2 wherein the power converter part of an automobile power system.

4. The method of claim 3 wherein the power converter is part of a power distribution network.

5. The method of claim 1 wherein the electronic component comprises a switching device.

6. The method of claim 5 wherein the performance degradation characteristic is an impedance change within the switching component.

7. The method of claim 1 wherein the performance degradation characteristic is a change in at least one of capacitance and equivalent series resistance of a capacitor.

8. The method of claim 1 wherein the performance degradation characteristic is a change in an inductor.

9. The method of claim 1 wherein the test signal is transmitted using spread spectrum time domain reflectometry.

10. The method of claim 1 wherein the electronic component is one or more components in a photovoltaic system.

11. The method of claim 10 further comprising processing the reflected signal to determine whether a ground fault is present in the photovoltaic system.

12. A system comprising:

a power converter configured to modify properties of electrical power propagating in the system;

a state of health testing device configured to transmit a test signal into a power converter while the power converter is functioning within the system, said state of health testing device further configured to monitor reflections from the test signal and process the received data in order to analyze effects that occur as a result of degradation of components within the power converter.

13. The system of claim 12 wherein the system is a high voltage DC power distribution system.

14. The system of claim 12 wherein the system is an automobile power system.

15. The system of claim 12 wherein the component is at least one MOSFET and state of health testing device monitors R_DS of one or more of the MOSFETs.

16. The system of claim 12 wherein the component is an IGBT and state of health testing device monitors one or more of threshold voltage, transconductance, and collector-emitter ON voltage.

17. The system of claim 12 wherein component is at least one capacitor and state of health testing device monitors changes in one or more of equivalent series resistance and capacitance of the capacitors.

18. The system of claim 12 wherein said system includes a plurality of power converters.

19. The system of claim 18 wherein the plurality of power converters are configured to be monitored by a single state of health testing device.

20. The system of claim 12 wherein the plurality of power converters are configured to be monitored by a plurality state of health testing devices.

21. A device comprising:

at least one power converter, said power converter configured to connect to a testing system while in live operation, wherein the power converter is configured to receive a test signal which does not interfere with the functionality of the power converter and is configured to output a reflected signal that conveys data which may be analyzed to determine one or more degradation properties of at least one component within the at least one power converter.

22. The device of claim 21 wherein the degradation properties are indicative of degradation of one or more of a MOSFET, capacitor, IGBT, and an inductor.