# US 2016/0041219 A1 · Method and device for determining power system parameters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0041219 A1 - Document ID: US20160041219A1 - Status: Published application - Kind: A1 - Application number: 14/883,655 - Filed: 2015-10-15 - Published: 2016-02-11 - Earliest claimed: 2013-04-16 - Assignees: Megger Limited - Applicants: Megger Ltd. - Inventors: Peter WERELIUS; Mats ÖHLEN; Alan Lyle PURTON - Web page: https://patentgrep.com/patent/US20160041219A1 ## CPC - 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 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 31/1263: {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 31/1272: {of cable, line or wire insulation, e.g. using partial discharge measurements (locating faults in cables G01R31/083)} - G01R 31/34: Testing dynamo-electric machines - G01R 31/62: Testing of transformers - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A method for determining a dielectric parameter of an electrical insulation of a power system component comprises the following steps: determining the activation energy of the electrical insulation, determining the actual temperature (T1) of the electrical insulation and the temperature (T2) to which the measurement is to be corrected, calculating a correction factor (Axy) by means of the Arrhenius equation, stimulating the electrical insulation with a DC voltage stimulation signal; determining a response for the power system to the DC voltage stimulation signal at the actual temperature, and determining the parameter of the electrical insulation at the temperature to which the measurement is to be corrected based on the response modified by means of the correction factor. Thereby, the individual characteristics of the power system apparatus insulation is taken into account. A device for determining a dielectric parameter of an electrical insulation of a power system component is also provided. ## Claims ### Claim 1 A method for determining a dielectric parameter of an electrical insulation of a power system component, comprising the following steps: determining an activation energy of the electrical insulation, determining an actual temperature (T1) of the electrical insulation and a temperature (T2) to which the measurement is to be corrected, calculating a correction factor (Axy) by means of the Arrhenius equation, stimulating the electrical insulation with a DC voltage stimulation signal; determining a response for the power system to the DC voltage stimulation signal at the actual temperature, and determining the parameter of the electrical insulation at the temperature to which the measurement is to be corrected based on the response modified by means of the correction factor. ### Claim 2 (depends on 1) The method according to claim 1, wherein the step of determining the parameter of the electrical insulation is performed in a frequency domain. ### Claim 3 (depends on 2) The method according to claim 2, wherein the frequencies are shifted by the correction factor (Axy). ### Claim 4 (depends on 1) The method according to claim 1, wherein the step of determining the parameter of the electrical insulation is performed in a time domain. ### Claim 5 (depends on 4) The method according to claim 4, wherein the time is shifted by the correction factor (Axy) and an amplitude is scaled for an insulation resistance/current reading by the correction factor (Axy). ### Claim 6 (depends on 1) The method according to claim 1, wherein the electrical insulation comprises one single material, and wherein the parameter of the electrical insulation is determined based on the response modified by means of the correction factor calculated based on one single activation energy. ### Claim 7 (depends on 1) The method according to claim 1, wherein the electrical insulation comprises at least two materials. ### Claim 8 (depends on 7) The method according to claim 7, comprising the steps of conducting a measurement of dielectric response as function of time at the actual temperature (T1) of the electrical insulation, and dividing the measurement data into data for first, second, and any further material. ### Claim 9 (depends on 8) The method according to claim 8, wherein the step of dividing the measurement data into data for first, second, and any further material is performed by means of a mathematical model, such as an XY model for dielectric frequency response measurements. ### Claim 10 (depends on 8) The method according to claim 8, wherein the temperature correction is used for each material, the method comprising the additional step of determining the total dielectric response at the temperature to which the measurement is to be corrected. ### Claim 11 (depends on 1) The method according to claim 1, wherein the dielectric parameter is any of the following: insulation resistance, dielectric absorption ratio, and polarisation index. ### Claim 12 (depends on 1) The method according to claim 1, wherein the power system component is any of the following: a rotating machine, a transformer, a bushing and a power cable. ### Claim 13 (depends on 1) The method according to claim 1, wherein a correction is performed for several temperatures in an interval for determining the temperature dependence of the dielectric parameter, preferably insulation resistance and polarisation index. ### Claim 14 (depends on 1) A device for determining a dielectric parameter of an electrical insulation of a power system component, comprising a test controller, a stimulator circuit adapted to stimulate the insulation of the power system component, a detector circuit adapted to detect, record, and/or measure the response of the power system component, an input device adapted to input test values and/or parameter values to command the stimulator circuit, and an output device, wherein the test controller is adapted to control the device to perform the method according to claim 1. ### Claim 15 (depends on 1) A computer program, comprising computer readable code means, which when run in a device causes the device to perform the method according to claim 1. ### Claim 16 (depends on 15) A computer program product comprising a computer program according to claim 15.