# US 2014/0152224 A1 · Motor drive circuit, motor device, and moving vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152224 A1 - Document ID: US20140152224A1 - Status: Published application - Kind: A1 - Application number: 14/131,651 - Filed: 2012-05-15 - Published: 2014-06-05 - Earliest claimed: 2011-07-29 - Assignees: Sanyo Electric Co., Ltd. - Inventors: Yoichi Enomoto; Hiroshi Takao; Yoshihiko Maeda; Hoshihito Okada - Web page: https://patentgrep.com/patent/US20140152224A1 ## CPC - B60L 3/0069: {relating to the isolation, e.g. ground fault or leak current} - G01R 31/40: Testing power supplies (testing photovoltaic devices H02S50/10) - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - H02P 29/0241: {the fault being an overvoltage} - G01R 27/025: {Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters} - G01R 31/343: {in operation} - G01R 31/52: Testing for short-circuits, leakage current or ground faults - Y02T 10/64: Electric machine technologies in electromobility - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A motor drive circuit comprises: a DC power supply; power supply lines; an inverter which has upper arm switch elements and lower arm switch elements; and a detection unit for detecting, based on a power state on the previous stage side of the inverter, the insulation resistances of the motor drive circuit and the motor. The detection unit performs a first detection operation for detecting the insulation resistances by using the output of the DC power supply while the upper arm switch elements and the lower arm switch elements are all turned off and a second detection operation for detecting the insulation resistances by using the output of the DC power supply while the elements of one of the upper arm switch elements and the lower arm switch elements are all turned off and at least one of the elements of the other one is turned on. ## Claims ### Claim 1 A motor drive circuit comprising: a DC power supply; power supply lines connected to the DC power supply; and an inverter which has a group of at least one upper arm switch device and another group of at least one lower arm switch device of one phase or of a plurality of phases connected in series between the power supply lines, and to which a motor is connected between the upper arm switch device and the lower arm switch device; the motor drive circuit includes a detection portion that detects insulation resistances of the motor drive circuit and the motor based on a power state on a previous stage with respect to the inverter, wherein the detection portion performs: a first detection operation for detecting the insulation resistance by using an output from the DC power supply in a state where all of the upper arm switch devices and all of the lower arm switch devices are kept in an off-state; and a second detection operation for detecting the insulation resistance by using the output from the DC power supply in a state where all of the upper arm switch devices of the one group or all of the lower arm switch devices of the other group are kept in the off-state and at least one of the upper arm switch devices of the one group or at least one of the lower arm switch devices of the other group is kept in an on-state. ### Claim 2 (depends on 1) The motor drive circuit according to claim 1, wherein the detection portion performs the second detection operation after it is detected by the first detection operation that the insulation resistance is normal, detects, based on the first detection operation, whether the insulation resistance on the previous stage with respect to the inverter is good or not, and detects, based on the second detection operation, whether the insulation resistance on a post stage with respect to the inverter is good or not. ### Claim 3 (depends on 2) The motor drive circuit according to claim 2, including a plurality of voltage division resistors connected in series between the power supply lines; a portion between the voltage division resistors is grounded; and based on a voltage value obtained by dividing a voltage by using the voltage division resistors, the detection portion detects whether the insulation resistance is good or not. ### Claim 4 (depends on 3) The motor drive circuit according to claim 3, wherein in the first detection operation, the detection portion detects that the insulation resistance of the power supply line on a positive-polar side is defective when the voltage value exceeds a first predetermined detection threshold value, and detects that the insulation resistance of the power supply line on a negative-polar side is defective when the voltage value is under a second predetermined detection threshold value. ### Claim 5 (depends on 2) The motor drive circuit according to claim 2, wherein the inverter includes the at least one upper arm switch device and at least one lower arm switch device of the plurality of phases; the second detection operation is an operation in which the insulation resistance is detected by using the output from the DC power supply in a state where all of the upper arm switch devices are kept in an off-state and one of the lower arm switch devices is kept in an on-state; and the detection portion switches the lower arm switch devices to be turned on among the plurality of phases during an execution time of the second detection operation. ### Claim 6 (depends on 2) The motor drive circuit according to claim 2, wherein the inverter includes the at least one upper arm switch device and at least one lower arm switch device of the plurality of phases; the second detection operation is an operation in which the insulation resistance is detected by using the output from the DC power supply in a state where all of the lower arm switch devices are kept in an off-state and one of the upper arm switch devices is kept in an on-state; and the detection portion switches the upper arm switch devices to be turned on among the plurality of phases during an execution time of the second detection operation. ### Claim 7 (depends on 1) A motor device comprising: the motor drive circuit according to claim 1; and a motor connected between the upper arm switch device and the lower arm switch device. ### Claim 8 (depends on 7) A moving body comprising the motor device according to claim 7.