# US 2021/0278465 A1 · Diagnostic apparatus for electric drive object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278465 A1 - Document ID: US20210278465A1 - Status: Published application - Kind: A1 - Application number: 17/314,046 - Filed: 2021-05-07 - Published: 2021-09-09 - Earliest claimed: 2018-11-09 - Assignees: Kabushiki Kaisha Yaskawa Denki - Applicants: Kabushiki Kaisha Yaskawa Denki - Inventors: Hideaki IKE - Web page: https://patentgrep.com/patent/US20210278465A1 ## CPC - H02M 1/32: Means for protecting converters other than automatic disconnection - F04D 15/0088: {Testing machines} - F04D 25/0666: {a sensor is integrated into the pump/motor design} - G01R 31/343: {in operation} - H02M 7/48: using discharge tubes with control electrode or semiconductor devices with control electrode - H02P 23/14: Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage - H02P 27/08: with pulse width modulation - H02P 27/085: {wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency} - H02P 29/024: Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A diagnostic apparatus for an electric drive object that generates a drive force in response to receiving electric power, the diagnostic apparatus includes a circuitry configured to: acquire time series force data associated with the drive force; identify a force oscillation level associated with the drive force based on the force data; set an oscillation threshold at a first level when the drive object operates at a first speed and set the threshold at a second level higher than the first level when the drive object operates at a second speed higher than the first speed; and identify an irregularity of the drive object in response to determining that the force oscillation level exceeds the oscillation threshold. ## Claims ### Claim 1 A diagnostic apparatus for an electric drive object that generates a drive force in response to receiving electric power, the diagnostic apparatus comprising a circuitry configured to: acquire time series force data associated with the drive force; identify a force oscillation level associated with the drive force based on the force data; set an oscillation threshold at a first level when the drive object operates at a first speed and set the threshold at a second level higher than the first level when the drive object operates at a second speed higher than the first speed; and identify an irregularity of the drive object in response to determining that the force oscillation level exceeds the oscillation threshold. ### Claim 2 (depends on 1) The diagnostic apparatus according to claim 1, wherein the force data comprise time series data of an electrical current associated with the electric power. ### Claim 3 (depends on 1) The diagnostic apparatus according to claim 1, wherein the time series force data comprise time series measurements of the drive force. ### Claim 4 (depends on 1) The diagnostic apparatus according to claim 1, wherein the circuitry is further configured to set the threshold based on a threshold profile representing a predetermined relationship between an operating speed of the drive object and the oscillation threshold such that the oscillation threshold increases as the operating speed increases. ### Claim 5 (depends on 4) The diagnostic apparatus according to claim 4, wherein the threshold profile comprises a function. ### Claim 6 (depends on 4) The diagnostic apparatus according to claim 4, wherein the threshold profile comprises a discrete point sequence. ### Claim 7 (depends on 4) The diagnostic apparatus according to claims 4, wherein the circuitry is further configured to generate the threshold profile based on the force data acquired during a test operation of the drive object and set the oscillation threshold based on the threshold profile after the test operation. ### Claim 8 (depends on 7) The diagnostic apparatus according to claim 7, wherein the circuitry is further configured to derive a reference profile representing a relationship between the operating speed and the force oscillation level based on the force data acquired during the test operation, and generate the threshold profile based on the reference profile. ### Claim 9 (depends on 8) The diagnostic apparatus according to claim 8, wherein the circuitry is further configured to: derive the reference profile associated with a first rate of change of the force oscillation level as the operating speed is increased from the first speed to the second speed; and generate the threshold profile associated with a second rate of change of the oscillation threshold as the operating speed is increased from the first speed to the second speed, wherein the second rate of change is greater than the first rate of change. ### Claim 10 (depends on 1) The diagnostic apparatus according to claim 1, wherein the circuitry is further configured to calculate an oscillation amplitude of the force data as the force oscillation level. ### Claim 11 (depends on 1) The diagnostic apparatus according to claim 1, wherein the circuitry is further configured to calculate a trend value of the force data and calculate a difference between an instantaneous value of the force data and the trend value as the force oscillation level. ### Claim 12 (depends on 11) The diagnostic apparatus according to claim 11, wherein the circuitry is further configured to calculate the trend value by low-pass filtering on the force data. ### Claim 13 (depends on 1) A power conversion apparatus including the diagnostic apparatus according to claim 1, the power conversion apparatus comprising: power conversion circuitry configured to provide the electric power to the drive object; and control circuitry configured to control the power conversion circuitry and including the circuitry of the diagnostic apparatus. ### Claim 14 (depends on 13) The power conversion apparatus according to claim 13, wherein the control circuitry is further configured to control the power conversion circuitry to change the electric power in order to modulate an operating speed of the drive object. ### Claim 15 (depends on 14) The power conversion apparatus according to claim 14, wherein the control circuitry is further configured to: control the power conversion circuitry to provide the electric power for a test operation to the drive object; generate a threshold profile representing a relationship between the operating speed and the oscillation threshold based on the force data acquired during the test operation; and set the oscillation threshold based on the threshold profile after the test operation. ### Claim 16 (depends on 14) A pumping apparatus comprising: the power conversion apparatus according to claim 14; and the drive object, which is an electric pump driven by the electric power provided by the power conversion circuitry. ### Claim 17 (depends on 16) The pumping apparatus according to claim 16, further comprising an electrical component holder fixed to the electric pump to hold the power conversion apparatus. ### Claim 18 A diagnostic method for an electric drive object that generates a drive force in response to receiving electric power, the diagnostic method comprising: acquiring time series force data associated with the drive force; identifying a force oscillation level associated with the drive force based on the force data; setting an oscillation threshold at a first level when the drive object operates at a first speed and setting the threshold at a second level higher than the first level when the drive object operates at a second speed higher than the first speed; and identifying an irregularity of the drive object in response to determining that the force oscillation level exceeds the oscillation threshold. ### Claim 19 (depends on 18) The diagnostic method according to claim 18, wherein the force data comprise time series data of an electrical current associated the electric power. ### Claim 20 (depends on 18) The diagnostic method according to claim 18 further comprising setting the oscillation threshold based on a threshold profile representing a predetermined relationship between an operating speed of the drive object and the oscillation threshold such that the oscillation threshold increases as the operating speed increases.