# US 12,216,166 B2 · Diagnostic apparatus, diagnostic method, recording medium having recorded thereon diagnostic program, and power conversion apparatus including diagnostic apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,216,166 B2 - Document ID: US12216166B2 - Status: Granted - Kind: B2 - Application number: 17/728,931 - Filed: 2022-04-25 - Published: 2022-12-01 - Granted: 2025-02-04 - Earliest claimed: 2021-06-01 - Assignees: Fuji Electric Co., Ltd. - Applicants: Fuji Electric Co., Ltd. - Inventors: Hiroaki Ueta; Hiroyuki Kokubun - Web page: https://patentgrep.com/patent/US12216166B2 ## CPC - G01R 31/343: {in operation} - H02M 7/5395: by pulse-width modulation - H02H 7/085: against excessive load {(H02H6/00 takes precedence)} - H02M 7/06: using discharge tubes without control electrode or semiconductor devices without control electrode - H02M 7/5387: in a bridge configuration - H02P 29/024: Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load - G01R 23/02: Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage - H02H 7/0833: {for electric motors with control arrangements} - H02M 1/32: Means for protecting converters other than automatic disconnection - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract There is provided a diagnostic apparatus including: a data acquisition unit configured to acquire target data relating to a current value between a power conversion apparatus and a motor; a detection unit configured to detect a peak value in a time series waveform of the target data; a counting operation unit configured to use a frequency counting method to calculate an amplitude of the peak value and a frequency of occurrence of the amplitude; and a diagnostic unit configured to diagnose an abnormality of the motor based on the amplitude and the frequency of occurrence. The diagnostic unit diagnoses that the motor is abnormal when a statistic which is calculated from the amplitude and the frequency of occurrence of the amplitude does not satisfy a predetermined reference. ## Claims ### Claim 1 A diagnostic method comprising: controlling a motor to rotate; acquiring target data relating to a current value of electrical current between a power conversion apparatus and the motor; detecting at least three latest peak values in a time series waveform of the target data; using a frequency counting method to calculate an amplitude of each of the at least three latest peak values and a frequency of occurrence of the amplitude of each of the at least three latest peak values; diagnosing an abnormality of the motor based on the calculated amplitude of the at least three latest peak values and the frequency of occurrence of the amplitude of the at least three latest peak values; and stopping the rotation of the motor based on the diagnosed abnormality, wherein the amplitude of each of the at least three latest peak values is an absolute value of a difference in amplitude between two adjacent ones of the at least three latest peak values, and a weight of either 0.5 cycle or 1.0 cycle is assigned to each of the at least three latest peak values. ### Claim 2 A non-transient recording medium having recorded thereon a diagnostic program that is executed by a computer and causes the computer to: control a motor to rotate; acquire target data relating to a current value between a power conversion apparatus and the motor; detect at least three latest peak values in a time series waveform of the target data; use a frequency counting method to calculate an amplitude of each of the at least three latest peak values and a frequency of occurrence of the amplitude of the at least three latest peak values; diagnose an abnormality of the motor based on the calculated amplitude of the at least three latest peak values and the frequency of occurrence of the amplitude of the at least three latest peak values; and stop the rotation of the motor based on the diagnosed abnormality, wherein the amplitude of each of the at least three latest peak values is an absolute value of a difference in amplitude between two adjacent ones of the at least three latest peak values, and a weight of either 0.5 cycle or 1.0 cycle is assigned to each of the at least three latest peak values. ### Claim 3 (depends on 1) The diagnostic method according to claim 1, further comprising: diagnosing that the motor is abnormal when a statistic which is calculated from the amplitude and the frequency of occurrence does not satisfy a predetermined reference. ### Claim 4 (depends on 1) The diagnostic method according to claim 1, further comprising: diagnosing that the motor is abnormal when a magnitude of a change in a statistic which is calculated from the amplitude and the frequency of occurrence does not satisfy a predetermined reference. ### Claim 5 (depends on 3) The diagnostic method according to claim 3, further comprising: diagnosing that the motor is abnormal when a magnitude of a change in the statistic which is calculated from the amplitude and the frequency of occurrence does not satisfy a predetermined reference. ### Claim 6 (depends on 3) The diagnostic method according to claim 3, further comprising: setting a reference based on an amplitude and a frequency of occurrence which are calculated for a predetermined period. ### Claim 7 (depends on 4) The diagnostic method according to claim 4, further comprising: setting a reference based on an amplitude and a frequency of occurrence which are calculated for a predetermined period. ### Claim 8 (depends on 1) The diagnostic method according to claim 1, further comprising: providing a notification of the abnormality when the motor is diagnosed to be abnormal. ### Claim 9 (depends on 3) The diagnostic method according to claim 3, further comprising: providing a notification of the abnormality when the motor is diagnosed to be abnormal. ### Claim 10 (depends on 1) The diagnostic method according to claim 1, further comprising: performing a coordinate transformation of the target data, wherein the at least three peak values are detected in the time series waveform of the target data of which the coordinate transformation is performed. ### Claim 11 (depends on 3) The diagnostic method according to claim 3, further comprising: performing a coordinate transformation of the target data, wherein the at least three peak values are detected in the time series waveform of the target data of which the coordinate transformation is performed. ### Claim 12 (depends on 10) The diagnostic method according to claim 10, wherein the coordinate transformation is a dq transformation. ### Claim 13 (depends on 1) The diagnostic method according to claim 1, further comprising acquiring, in addition to the current value, data relating to a voltage value between the power conversion apparatus and the motor, as the target data. ### Claim 14 (depends on 3) The diagnostic method according to claim 3, further comprising acquiring, in addition to the current value, data relating to a voltage value between the power conversion apparatus and the motor, as the target data. ### Claim 15 (depends on 1) The diagnostic method according to claim 1, further comprising acquiring, in addition to the current value, data relating to a rotation speed of the motor, as the target data. ### Claim 16 (depends on 3) The diagnostic method according to claim 3, further comprising acquiring, in addition to the current value, data relating to a rotation speed of the motor, as the target data. ### Claim 17 (depends on 1) A power conversion method comprising: the diagnostic method according to claim 1. ### Claim 18 (depends on 3) A power conversion method comprising: the diagnostic method according to claim 3. ### Claim 19 (depends on 4) A power conversion method comprising: the diagnostic method according to claim 4.