# US 2019/0173390 A1 · Power conversion device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173390 A1 - Document ID: US20190173390A1 - Status: Published application - Kind: A1 - Application number: 16/196,049 - Filed: 2018-11-20 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Mitsubishi Electric Corporation; Honda Motor Co., Ltd. - Applicants: Mitsubishi Electric Corporation; Honda Motor Co., Ltd. - Inventors: Kazuki TAKEGAWA; Satoshi ISHIBASHI; Kazuhiko OTSUKA; Masaya TAKAHASHI - Web page: https://patentgrep.com/patent/US20190173390A1 ## CPC - H02M 7/48: using discharge tubes with control electrode or semiconductor devices with control electrode - H02M 7/4837: {Flying capacitor converters} - G01K 1/08: Protective devices, e.g. casings - H02M 1/32: Means for protecting converters other than automatic disconnection - H02P 3/18: for stopping or slowing an AC motor - H02P 25/04: Single phase motors, e.g. capacitor motors - H02P 25/24: Variable impedance in stator or rotor circuit - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - G01K 17/00: Measuring quantity of heat (measuring temperature by calorimetry G01K3/00 - G01K11/00; specially adapted for measuring thermal properties of materials, e.g. specific heat, heat of combustion G01N) - G01P 5/10: by measuring thermal variables - H02M 1/322: {Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock} - H02M 1/327: {against abnormal temperatures} - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H02M 7/53871: {with automatic control of output voltage or current} - H02P 1/04: Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter - H02P 3/16: by combined electrical and mechanical braking - H02P 6/14: Electronic commutators - H02P 29/68: based on the temperature of a drive component or a semiconductor component - H02P 2201/09: Boost converter, i.e. DC-DC step up converter increasing the voltage between the supply and the inverter driving the motor - 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) - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract In inverter control for supplying power to a motor, a power conversion device includes a temperature sensor for detecting a temperature of the inverter, a voltage sensor for detecting a voltage between terminals of a capacitor that smooths the voltage between terminals between the power source and the inverter, an inverter controller for controlling the inverter, a rotation speed sensor for detecting a rotation speed of the motor, an electric current sensor for detecting electric current supplied to the motor and a discharge determination instruction controller for giving an instruction for discharging electric charges accumulated in the capacitor, in which, control of reducing the rotation speed of the motor and discharge control of the capacitor are performed in accordance with the temperature of the inverter, the rotation speed of the motor and the electric current supplied to the motor. ## Claims ### Claim 1 A power conversion device connected between a power source and a motor comprising: an inverter for converting a voltage outputted from the power source into an AC voltage; a temperature sensor for detecting a temperature of the inverter; a capacitor that smooths a voltage between terminals between the power source and the inverter; a voltage sensor for detecting the voltage between terminals of the capacitor; an inverter controller for controlling the inverter; a rotation speed sensor for detecting a rotation speed of the motor; an electric current sensor for detecting electric current supplied to the motor; and a discharge determination instruction controller for giving an instruction for discharging electric charges accumulated in the capacitor, wherein, after control of reducing the rotation speed of the motor is performed in accordance with the temperature of the inverter, the rotation speed of the motor and the electric current supplied to the motor, discharge control of the capacitor is performed. ### Claim 2 (depends on 1) The power conversion device according to claim 1, wherein, in a case where the rotation speed of the motor exceeds a predetermined threshold value, the control of reducing the rotation speed is performed by the inverter controller, in a case where the temperature of the inverter exceeds a limit temperature of driving during the control of reducing the rotation speed, the control of reducing the rotation speed is stopped, and in a case where the temperature of the inverter is decreased to a temperature in which driving is possible, the control of reducing the rotation speed is started again. ### Claim 3 (depends on 1) The power conversion device according to claim 1, wherein, in a case where the rotation speed of the motor is less than the predetermined threshold value, discharge control of the capacitor is performed by the inverter controller, in a case where the temperature of the inverter exceeds a predetermined threshold value during the discharge control, the discharge control is stopped, and in a case where the temperature of the inverter is less than the threshold value, the discharge control is started again. ### Claim 4 (depends on 2) The power conversion device according to claim 2, wherein the stop of the control of reducing the rotation speed does not exceed a given period of time, in a case where the rotation speed is decreased to be less than the threshold value, the discharge control is performed, and in a case where the temperature of the inverter exceeds the limit temperature of driving during the discharge control, the discharge control is stopped. ### Claim 5 (depends on 3) The power conversion device according to claim 3, wherein a duration of the stop of the discharge control does not exceed a given period of time. ### Claim 6 (depends on 1) The power conversion device according to claim 1, wherein transition between the control of reducing the rotation speed and the discharge control is set by an electric current value detected by the electric current sensor. ### Claim 7 (depends on 2) The power conversion device according to claim 2, wherein, in a case where the electric current value detected by the electric current sensor exceeds the predetermined threshold value when the rotation speed sensor is not normal, the control of reducing the rotation speed is performed by the inverter controller. ### Claim 8 (depends on 3) The power conversion device according to claim 3, wherein, in a case where the electric current value detected by the electric current sensor is less than the predetermined threshold value when the rotation speed sensor is not normal, the discharge control is performed by the inverter controller. ### Claim 9 (depends on 1) The power conversion device according to claim 1, wherein, in a case where the rotation speed sensor and the electric current sensor are not normal at the time of performing control of reducing the rotation speed, the discharge control is performed after the control of reducing the rotation speed is performed during a predetermined period of time.