# US 8,542,125 B2 · System for verifying the integrity of an electrical union

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,542,125 B2
- Document ID: US8542125B2
- Status: Granted
- Kind: B2
- Application number: 13/143,669
- Filed: 2010-01-19
- Published: 2012-04-12
- Granted: 2013-09-24
- Earliest claimed: 2009-02-17
- Assignees: ROLLS-ROYCE plc
- Applicants: Aaron J. Stevens
- Inventors: Aaron J. Stevens
- Web page: https://patentgrep.com/patent/US8542125B2

## CPC

- F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)}
- F03D 7/0224: {Adjusting blade pitch}
- G01R 31/66: Testing of connections, e.g. of plugs or non-disconnectable joints (testing for incorrect line connections G01R31/55)
- Y02E 10/72: Wind turbines with rotation axis in wind direction
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F03D: WIND MOTORS
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A system is provided for verifying the performance of an electrical union. The electrical union provides electrical connectivity across an interface between first and second elements which rotate relative to each other. The system includes a signal source associated with the first element. The signal source is adapted to send an electrical signal over the union to the second element using a first signal frequency. The system further includes a frequency modulator associated with the second element. The frequency modulator is adapted to return the electrical signal over the union to the first element using a different second signal frequency. The system further includes a comparator which compares the signal sent by the data source to the signal returned by the frequency modulator. The comparator provides an output which identifies whether a discrepancy exists between the contents of the sent and returned signals.

## Claims

### Claim 1

A system for verifying performance of an electrical union providing electrical connectivity across an interface between first and second elements which rotate relative to each other, the system including:
a signal source associated with the first element, the signal source being adapted to send an electrical signal over the union to the second element using a first signal frequency;
a frequency modulator associated with the second element, the frequency modulator being adapted to return the electrical signal over the union to the first element using a different second signal frequency; and
a comparator which compares the signal sent by the signal source to the signal returned by the frequency modulator and provides an output which identifies whether a discrepancy exists between the contents of the sent and returned signals.

### Claim 2 (depends on 1)

A system according to claim 1 further including:
a further frequency modulator which, preliminary to the comparison by the comparator, modulates the frequency of the signal sent by the data source or the frequency of the signal returned by the frequency modulator so that the two signals use the same frequency.

### Claim 3 (depends on 2)

A system according to claim 2 wherein the further frequency modulator demodulates the signal returned by the frequency modulator to revert that signal to the first frequency.

### Claim 4 (depends on 1)

A system according to claim 1 wherein the comparator provides a binary signal output, a value of which depends on whether or not a discrepancy is identified.

### Claim 5 (depends on 1)

A system according to claim 1 further including:
a condition monitor which monitors the output of the comparator and issues an alert when a pattern of identified discrepancies indicates loss of integrity of the electrical union.

### Claim 6 (depends on 1)

A combination of the system according to claim 1 and the electrical union.

### Claim 7 (depends on 6)

A combination according to claim 6, wherein the electrical union is adapted to carry electrical power between the first and second elements.

### Claim 8 (depends on 6)

A combination according to claim 6, wherein the electrical union is a slip ring.

### Claim 9 (depends on 6)

A combination according to claim 6, including the first and second elements.

### Claim 10 (depends on 9)

A combination according to claim 9 wherein one of the first and second elements includes an electrical generator, power generated by the generator being transmitted over the union to the other element.

### Claim 11 (depends on 9)

A combination according to claim 9 wherein one of the first and second elements includes an electrically-powered device, power to operate the device being transmitted over the union from the other element.