# US 2020/0403530 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 2020/0403530 A1 - Document ID: US20200403530A1 - Status: Published application - Kind: A1 - Application number: 16/975,961 - Filed: 2019-02-05 - Published: 2020-12-24 - Earliest claimed: 2018-03-07 - Assignees: Sanden Holdings Corporation - Applicants: Sanden Holdings Corporation - Inventors: Tatsuki KASHIHARA - Web page: https://patentgrep.com/patent/US20200403530A1 ## CPC - H02M 7/003: {Constructional details, e.g. physical layout, assembly, wiring or busbar connections} - H02M 7/5395: by pulse-width modulation - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 7/53871: {with automatic control of output voltage or current} - H02P 27/085: {wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency} - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - 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) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract There is provided a power conversion device capable of effectively reducing a surge voltage generated by a parasitic inductance of a circuit. The power conversion device 1 is configured to operate a motor 8 driving a compression mechanism 7 of an electric compressor 16 by means of a three-phase inverter circuit 28 having a plurality of switching elements 18A to 18F. The power conversion device calculates a surge voltage value of each phase from a parasitic inductance of the circuit and phase currents iu, iv, and iw of the motor 8 to derive a phase in which the surge voltage value becomes maximum, and suppresses the switching of the switching elements 18A-18F of the phase having the maximum surge voltage value by a discontinuous modulation method. ## Claims ### Claim 1 A power conversion device comprising a three-phase inverter circuit having a plurality of switching elements to drive a motor, wherein the power conversion device calculates a surge voltage value of each phase from a parasitic inductance of the circuit and a phase current of the motor to derive a phase in which the surge voltage value becomes maximum, thereby suppressing the switching of the switching elements of the phase having the maximum surge voltage value. ### Claim 2 (depends on 1) The power conversion device according to claim 1, wherein the parasitic inductance of the circuit differs for each phase. ### Claim 3 (depends on 1) The power conversion device according to claim 1, including: a phase voltage command operation unit which calculates a sinusoidal modulation voltage command value to be applied to the motor, an inter-line modulation operation unit which calculates a discontinuous modulation voltage command value allowing ON/OFF states of predetermined one-phase switching elements of the three-phase inverter circuit to be fixed in a specified section and modulating ON/OFF states of other two-phase switching elements, based on the sinusoidal modulation voltage command value, and a PWM signal generation unit which generates a PWM signal PWM-controlling the three-phase inverter circuit, based on the discontinuous modulation voltage command value, wherein the inter-line modulation operation unit calculates the surge voltage value of each phase from the parasitic inductance of the circuit and the phase current of the motor to derive the phase in which the surge voltage value becomes maximum, thereby fixing the switching element of the phase having the maximum surge voltage value to an ON or OFF state. ### Claim 4 (depends on 3) The power conversion device according to claim 3, wherein the inter-line modulation operation unit compares the surge voltage values of the maximum phase and the minimum phase of the sinusoidal modulation voltage command value and fixes the switching element of the larger phase to the ON or OFF state. ### Claim 5 (depends on 1) The power conversion device according to claim 1, wherein the motor drives a compression mechanism of an electric compressor. ### Claim 6 (depends on 2) The power conversion device according to claim 2, including: a phase voltage command operation unit which calculates a sinusoidal modulation voltage command value to be applied to the motor, an inter-line modulation operation unit which calculates a discontinuous modulation voltage command value allowing ON/OFF states of predetermined one-phase switching elements of the three-phase inverter circuit to be fixed in a specified section and modulating ON/OFF states of other two-phase switching elements, based on the sinusoidal modulation voltage command value, and a PWM signal generation unit which generates a PWM signal PWM-controlling the three-phase inverter circuit, based on the discontinuous modulation voltage command value, wherein the inter-line modulation operation unit calculates the surge voltage value of each phase from the parasitic inductance of the circuit and the phase current of the motor to derive the phase in which the surge voltage value becomes maximum, thereby fixing the switching element of the phase having the maximum surge voltage value to an ON or OFF state. ### Claim 7 (depends on 2) The power conversion device according to claim 2, wherein the motor drives a compression mechanism of an electric compressor. ### Claim 8 (depends on 3) The power conversion device according to claim 3, wherein the motor drives a compression mechanism of an electric compressor. ### Claim 9 (depends on 4) The power conversion device according to claim 4, wherein the motor drives a compression mechanism of an electric compressor.