# US 2021/0242798 A1 · Variable mutual off time control for automotive power converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242798 A1 - Document ID: US20210242798A1 - Status: Published application - Kind: A1 - Application number: 16/778,808 - Filed: 2020-01-31 - Published: 2021-08-05 - Earliest claimed: 2020-01-31 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Boris CURUVIJA; Baoming GE; Fan XU - Web page: https://patentgrep.com/patent/US20210242798A1 ## CPC - H02M 7/527: by pulse width modulation - H02M 7/5387: in a bridge configuration - B60L 3/003: {relating to inverters} - B60L 15/08: using pulses - B60L 50/10: using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines - H02M 1/12: Arrangements for reducing harmonics from AC input or output - H02M 1/38: Means for preventing simultaneous conduction of switches - H02M 3/158: including plural semiconductor devices as final control devices for a single load - B60L 2210/40: DC to AC converters - B60L 2240/429: Current - B60L 2240/80: Time limits - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/72: Electric energy management in electromobility - 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) - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An automotive power converter may be controlled by detecting a magnitude of current output by a phase leg of the automotive power converter, selecting a mutual off time for switches of the phase leg according to the magnitude, and generating pulse width modulation signals for the switches having the mutual off time to operate the switches to transfer power between a traction battery and electric machine. ## Claims ### Claim 1 An automotive vehicle comprising: a traction battery; an electric machine; an inverter configured to transfer power between the traction battery and electric machine, and including a pair of switches defining a phase leg for the electric machine; and a controller configured to complementarily operate the switches with respective pulse width modulated signals that each have a duty cycle and collectively define a mutual off time between pulses, wherein the mutual off time varies according to a magnitude of current output by the phase leg such that as the magnitude increases, the mutual off time increases while the duty cycle remains constant and as the magnitude decreases, the mutual off time decreases while the duty cycle remains constant. ### Claim 2 (depends on 1) The automotive vehicle of claim 1 further comprising a sensor configured to detect the magnitude of current. ### Claim 3 (depends on 3) The automotive vehicle of claim 3, wherein the controller is further configured to select the mutual off time according to the magnitude. ### Claim 4 (depends on 1) The automotive vehicle of claim 1, wherein the electric machine is a motor. ### Claim 5 (depends on 1) The automotive vehicle of claim 1, wherein the electric machine is a generator. ### Claim 6 A method for controlling an automotive power converter, the method comprising: detecting a magnitude of current output by a phase leg of the automotive power converter, wherein the phase leg is defined by a pair of switches; selecting a mutual off time according to the magnitude; and generating pulse width modulation signals for the switches having the mutual off time to transfer power between a traction battery and electric machine such that as the magnitude decreases the mutual off time decreases. ### Claim 7 (depends on 6) The method of claim 6, wherein the selecting includes, responsive to the magnitude exceeding a first predetermined threshold, setting the mutual off time to a first value. ### Claim 8 (depends on 7) The method of claim 7, wherein the selecting further includes, responsive to the magnitude being less than a second predetermined threshold, setting the mutual off time to a second value less than the first value. ### Claim 9 (depends on 8) The method of claim 8, wherein the first and second predetermined thresholds are same. ### Claim 10 (depends on 8) The method of claim 8, wherein the first and second values are less than 0.5 microseconds. ### Claim 11 A power system for an automotive vehicle comprising: a power inverter including a pair of switches defining a phase leg; a current sensor configured to measure a magnitude of current output by the phase leg; and a controller configured to operate the switches with respective pulse width modulated signals that each have a duty cycle and collectively define a mutual off time between pulses, and to alter the mutual off time according to the magnitude such that the mutual off time decreases as the magnitude decreases while the duty cycle remains constant. ### Claim 12 (depends on 11) The power system of claim 11, wherein the controller is further configured to alter the mutual off time according to the magnitude such that the mutual off time increases as the magnitude increases. ### Claim 13 (depends on 1) The power system of claim 1, wherein the electric machine is a motor. ### Claim 14 (depends on 1) The power system of claim 1, wherein the electric machine is a generator.