# US 2020/0400736 A1 · Systems and methods for acoustically detecting dielectric breakdown and partial discharge events in electrical devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0400736 A1 - Document ID: US20200400736A1 - Status: Published application - Kind: A1 - Application number: 16/447,774 - Filed: 2019-06-20 - Published: 2020-12-24 - Earliest claimed: 2019-06-20 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Christopher Mark Severns; John R. Hull - Web page: https://patentgrep.com/patent/US20200400736A1 ## CPC - G01R 31/1209: {using acoustic measurements (acoustic measurements G01H3/00)} - G01R 31/1263: {of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation} - G01R 17/10: AC or DC measuring bridges - G01R 31/1227: {of components, parts or materials (G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16)} - G01R 31/14: Circuits therefor {, e.g. for generating test voltages, sensing circuits (G01R31/1209 - G01R31/1227 take precedence; for testing switches G01R31/327)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A system for acoustically detecting dielectric breakdown of, or partial discharge within, or on, an electrical device includes at least one electroacoustic (EA) transducer configured to detect an acoustic vibration of the electrical device, and a controller electrically connected to the at least one EA transducer. The controller is configured to receive a signal from the at least one EA transducer, and analyze the signal to determine whether the signal includes data associated with an acoustic vibration in a frequency range of dielectric breakdown and/or partial discharge of the electrical device. The applicability of such a system includes, but is not limited to, electronic parts or assembly screening, life characterization testing for materials and processes, diagnostic methods or aides, augmenting testing of components, assemblies or systems, and in service monitoring to support preventative or condition based maintenance to avert an in-service issues. ## Claims ### Claim 1 A system for acoustically detecting dielectric breakdown or partial discharge of an electrical device, the system comprising: at least one electroacoustic (EA) transducer configured to detect an acoustic vibration of the electrical device; and a controller electrically connected to the at least one EA transducer, the controller configured to execute instructions stored in a memory, which when executed, cause the controller to at least: receive a signal from the at least one EA transducer; analyze the signal received from the at least one EA transducer; determine, based upon the analyzing, whether the signal received from the at least one EA transducer includes data associated with an acoustic vibration in a frequency range of partial discharge of the electrical device; and generate an alert in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge. ### Claim 2 (depends on 1) The system of claim 1, further comprising a quadrilateral detection circuit having four legs, wherein three of the four legs have a known resistance, and wherein one of the four legs includes the electrical device, and wherein the quadrilateral detection circuit is electrically connected to the controller. ### Claim 3 (depends on 2) The system of claim 2, wherein the quadrilateral detection circuit is one of a Wheatstone Bridge or a Schering Bridge. ### Claim 4 (depends on 2) The system of claim 2, wherein the instructions when executed, further cause the controller to at least: receive at least one measurement from the quadrilateral detection circuit; and in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, verify the determination based upon the at least one measurement received from the quadrilateral detection circuit. ### Claim 5 (depends on 4) The system of claim 4, wherein to verify the determination that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, the instructions, when executed, further cause the controller to at least: calculate, from a time period of the acoustic vibration in the frequency range of partial discharge and a speed of sound stored in the memory, a first estimate of at least one physical dimension of a void in a dielectric of the electrical device, the void producing partial discharge; calculate, from the at least one measurement received from the quadrilateral detection circuit, an electric field within the void and, from the calculated electric field, a second estimate of the at least one physical dimension of the void in the dielectric of the electrical device; and compare the first estimate of the at least one physical dimension to the second estimate of the at least one physical dimension. ### Claim 6 (depends on 1) The system of claim 1, wherein EA transducer is a contact microphone configured to be mechanically coupled to a dielectric of the electrical device to detect the acoustic vibration. ### Claim 7 (depends on 1) The system of claim 1, wherein EA transducer is a piezoelectric microphone configured to be mechanically coupled to a dielectric of the electrical device to detect the acoustic vibration. ### Claim 8 (depends on 1) The system of claim 1, wherein the acoustic vibration is structural within a dielectric of the electrical device, and wherein EA transducer is configured to be mechanically coupled to the dielectric of the electrical device to detect the acoustic vibration. ### Claim 9 An electrical system comprising: an electrical device; at least one electroacoustic (EA) transducer mechanically coupled to the electrical device and configured to detect an acoustic vibration of the electrical device; and a controller electrically connected to the at least one EA transducer, the controller configured to execute instructions stored in a memory, which when executed, cause the controller to at least: receive a signal from the at least one EA transducer; analyze the signal received from the at least one EA transducer; determine, based upon the analyzing, whether the signal received from the at least one EA transducer includes data associated with an acoustic vibration of the electrical device in a frequency range of partial discharge of the electrical device; and generate an alert in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge. ### Claim 10 (depends on 9) The electrical system of claim 9, further comprising a quadrilateral detection circuit having four legs, wherein three of the four legs have a known resistance, and wherein one of the four legs includes the electrical device, and wherein the quadrilateral detection circuit is electrically connected to the controller. ### Claim 11 (depends on 10) The electrical system of claim 10, wherein the quadrilateral detection circuit is one of a Wheatstone Bridge or a Schering Bridge. ### Claim 12 (depends on 10) The electrical system of claim 10, wherein the instructions when executed, further cause the controller to at least: receive at least one measurement from the quadrilateral detection circuit; and in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, verify the determination based upon the at least one measurement received from the quadrilateral detection circuit. ### Claim 13 (depends on 12) The electrical system of claim 12, wherein to verify the determination that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, the instructions, when executed, further cause the controller to at least: calculate, from a time period of the acoustic vibration in the frequency range of partial discharge and a speed of sound stored in the memory, a first estimate of at least one physical dimension of a void in a dielectric of the electrical device, the void producing partial discharge; calculate, from the at least one measurement received from the quadrilateral detection circuit, an electric field within the void and, from the calculated electric field, a second estimate of the at least one physical dimension of the void in the dielectric of the electrical device; and compare the first estimate of the at least one physical dimension to the second estimate of the at least one physical dimension. ### Claim 14 (depends on 9) The electrical system of claim 9, wherein the electrical device is configured to control an aerospace system, and wherein the aerospace system generates ambient noise in a frequency range lower than the frequency range of partial discharge. ### Claim 15 (depends on 9) The electrical system of claim 9, wherein the acoustic vibration is structural within a dielectric of the electrical device, and wherein EA transducer is configured to be mechanically coupled to the dielectric of the electrical device to detect the acoustic vibration. ### Claim 16 (depends on 9) The electrical system of claim 9, wherein EA transducer is a contact microphone configured to be mechanically coupled to a dielectric of the electrical device to detect the acoustic vibration. ### Claim 17 (depends on 9) The electrical system of claim 9, wherein EA transducer is a piezoelectric microphone configured to be mechanically coupled to a dielectric of the electrical device to detect the acoustic vibration. ### Claim 18 A method for acoustically detecting partial discharge of an electrical device, the method comprising: receiving, by a controller electrically connected to at least one electroacoustic (EA) transducer, a signal from the at least one EA transducer, the EA transducer mechanically coupled to the electrical device and configured to detect an acoustic vibration of the electrical device; analyzing, by the controller, the signal received from the at least one EA transducer; determining, by the controller and based upon the analyzing, whether the signal received from the at least one EA transducer includes data associated with an acoustic vibration in a frequency range of partial discharge of the electrical device; and generating an alert in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge. ### Claim 19 (depends on 18) The method of claim 18, further comprising: receiving, by the controller, at least one measurement from a quadrilateral detection circuit having four legs, wherein three of the four legs have a known resistance, and wherein one of the four legs includes the electrical device, and wherein the quadrilateral detection circuit is electrically connected to the controller; and in response to determining that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, verifying, by the controller, the determination based upon the at least one measurement received from the quadrilateral detection circuit. ### Claim 20 (depends on 19) The method of claim 19, wherein to verify the determination that the signal received from the at least one EA transducer includes the data associated with the acoustic vibration in the frequency range of partial discharge, the method further comprises: calculating, by the controller and from a time period of the acoustic vibration in the frequency range of partial discharge and a speed of sound stored in a memory, a first estimate of at least one physical dimension of a void in a dielectric of the electrical device, the void producing the partial discharge; calculating, by the controller and from the at least one measurement received from the quadrilateral detection circuit, an electric field within the void and, from the calculated electric field, a second estimate of the at least one physical dimension of the void in the dielectric of the electrical device; and comparing, by the controller, the first estimate of the at least one physical dimension to the second estimate of the at least one physical dimension.