# Method of detecting system function by measuring frequency response

## Abstract

Real time battery impedance spectrum is acquired using one time record, Compensated Synchronous Detection (CSD). This parallel method enables battery diagnostics. The excitation current to a test battery is a sum of equal amplitude sin waves of a few frequencies spread over range of interest. The time profile of this signal has duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known, synchronous detection processes the time record and each component, both magnitude and phase, is obtained. For compensation, the components, except the one of interest, are reassembled in the time domain. The resulting signal is subtracted from the original signal and the component of interest is synchronously detected. This process is repeated for each component.

- Inventors:

- Publication Date:

- Research Org.:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1245956

- Patent Number(s):
- 7,395,163

- Application Number:
- 11/825,629

- Assignee:
- Montana Tech of the University of Montana (Butte, MT)

- Resource Type:
- Patent

- Resource Relation:
- Patent File Date: 2007 Jul 05

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 97 MATHEMATICS AND COMPUTING; 36 MATERIALS SCIENCE; 25 ENERGY STORAGE

### Citation Formats

```
Morrison, John L., and Morrison, William H.
```*Method of detecting system function by measuring frequency response*. United States: N. p., 2008.
Web.

```
Morrison, John L., & Morrison, William H.
```*Method of detecting system function by measuring frequency response*. United States.

```
Morrison, John L., and Morrison, William H. Tue .
"Method of detecting system function by measuring frequency response". United States. https://www.osti.gov/servlets/purl/1245956.
```

```
@article{osti_1245956,
```

title = {Method of detecting system function by measuring frequency response},

author = {Morrison, John L. and Morrison, William H.},

abstractNote = {Real time battery impedance spectrum is acquired using one time record, Compensated Synchronous Detection (CSD). This parallel method enables battery diagnostics. The excitation current to a test battery is a sum of equal amplitude sin waves of a few frequencies spread over range of interest. The time profile of this signal has duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known, synchronous detection processes the time record and each component, both magnitude and phase, is obtained. For compensation, the components, except the one of interest, are reassembled in the time domain. The resulting signal is subtracted from the original signal and the component of interest is synchronously detected. This process is repeated for each component.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2008},

month = {7}

}

Works referenced in this record:

##
Model validation approaches for nonlinear feedback systems using frequency response measurements

conference, January 1999

- Smith, R.; Banaszuk, A.; Dullerud, G.
- Decision and Control, 1999. Proceedings of the 38th IEEE Conference on

##
Accurate method of representation of high-voltage measuring systems and its application in high-impulse-voltage measurements

journal, March 1989

- Nikolopoulos, P. N.; Topalis, F. V.
- IEE Proceedings A (Physical Science, Measurement and Instrumentation, Management and Education), Vol. 136, Issue 2, p. 66-72