# US 10,770,970 B2 · Flying capacitor based variable voltage converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,970 B2 - Document ID: US10770970B2 - Status: Granted - Kind: B2 - Application number: 15/619,118 - Filed: 2017-06-09 - Published: 2018-12-13 - Granted: 2020-09-08 - Earliest claimed: 2017-06-09 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Shuitao Yang; Yan Zhou; Lihua Chen; Baoming Ge; Fan Xu; Mohammed Khorshed Alam - Web page: https://patentgrep.com/patent/US10770970B2 ## CPC - B60L 15/007: {Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles} - B60L 50/51: characterised by AC-motors - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H02M 7/53873: {with digital control} - B60L 2210/10: DC to DC converters - B60L 2210/40: DC to AC converters - B60L 2240/526: Operating parameters - B60L 2240/527: Voltage - B60L 2240/529: Current - H02M 1/0003: {Details of control, feedback or regulation circuits} - 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 - 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 - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A powertrain for a vehicle may include a variable voltage converter (VVC), and a controller. The VVC may include an inductor, a bus capacitor and a flying capacitor. The controller may be configured to, in response to a power demand signal exceeding a threshold, modulate switches of the VVC such that an inductor current created by a collapsing field of the inductor is directed into the flying capacitor or the bus capacitor such that a bus capacitor voltage exceeds a flying capacitor voltage, and in response to the power demand signal dropping below the threshold, modulate switches such that the flying capacitor and the bus capacitor are coupled in parallel. ## Claims ### Claim 1 A powertrain for a vehicle comprising: a variable voltage converter (VVC) including an inductor, a bus capacitor and a flying capacitor; and a controller configured to, in response to a power demand signal exceeding a threshold, modulate switches of the VVC such that an inductor current created by a collapsing field of the inductor is directed into the flying capacitor or the bus capacitor such that a bus capacitor voltage exceeds a flying capacitor voltage, and in response to the power demand signal dropping below the threshold, modulate switches such that the flying capacitor and the bus capacitor are coupled in parallel. ### Claim 2 (depends on 1) The powertrain of claim 1, wherein the VVC is coupled between a traction battery and an electric drive unit. ### Claim 3 (depends on 1) The powertrain of claim 1, wherein the switches of the VVC include 4 switches coupled in series between a negative and positive output terminal of the VVC. ### Claim 4 (depends on 3) The powertrain of claim 3, wherein the switches of the VVC include a first switch coupled between a second switch and a positive output terminal, the second switch coupled between the first switch and a third switch, the third switch coupled between the second switch and a fourth switch, and the fourth switch coupled between the third switch and a negative output terminal. ### Claim 5 (depends on 4) The powertrain of claim 4, wherein the flying capacitor is coupled between a top junction between the first and second switch and a second junction between the third and fourth switch and the inductor is coupled between a positive input terminal and a middle point between the second and third switch. ### Claim 6 (depends on 5) The powertrain of claim 5, where the controller is further configured to, alternately flow the inductor current into the flying capacitor and bus capacitor coupled in series by the switches, or flow the inductor current into the bus capacitor, while the flying capacitor is coupled in series with the bus capacitor by the switches and bypassed by a diode. ### Claim 7 (depends on 5) The powertrain of claim 5, where the controller is further configured to, in response to a power demand signal transitioning to negative, couple the flying capacitor and the bus capacitor in parallel and operate, in a steady-state, the switches in a pass-through mode to flow charge, wherein the first, second and fourth switches conduct and the third switch is turned off. ### Claim 8 (depends on 1) The powertrain of claim 1, wherein the switches are insulated gate bipolar junction transistors (IGBTs) or metal oxide semiconductor field effect transistors (MOSFETs). ### Claim 9 A method of controlling a powertrain converter comprising: directing current into an inductor of the converter to create a field; in response to a power demand signal exceeding a threshold, collapsing the field to flow a charge to a flying capacitor to boost a voltage of a bus capacitor such that the voltage of the bus capacitor exceeds a voltage of the flying capacitor; and in response to a power demand signal dropping below the threshold, coupling the flying capacitor and the bus capacitor in parallel and directing charge into both the flying capacitor and the bus capacitor as the field collapses. ### Claim 10 (depends on 9) The method of claim 9 further comprising modulating switches of the converter by a controller to direct the current into the inductor and to collapse the field. ### Claim 11 (depends on 10) The method of claim 10, wherein the field collapses to flow a charge to the bus capacitor and the flying capacitor. ### Claim 12 (depends on 10) The method of claim 10 further including, in response to a power demand signal transitioning to negative, coupling the flying capacitor and the bus capacitor in parallel and operating, in a steady-state, the switches in a pass-through mode to flow charge. ### Claim 13 A vehicle comprising: an electric machine configured to propel the vehicle; a variable voltage converter (VVC) including an inductor, a bus capacitor and a flying capacitor; and a controller configured to modulate switches of the VVC in a boost mode such that an inductor current created by a collapsing field of the inductor is boosted by the flying capacitor and directed into the bus capacitor at a drive voltage of the electric machine and, in response to a power demand signal transitioning to negative, operate, in a steady-state, the switches in a pass-through mode to couple the flying capacitor and the bus capacitor in parallel and flow charge. ### Claim 14 (depends on 13) The vehicle of claim 13, wherein the switches of the VVC include a first switch coupled between a second switch and a positive output terminal, the second switch coupled between the first switch and a third switch, the third switch coupled between the second switch and a fourth switch, and the fourth switch coupled between the third switch and a negative output terminal. ### Claim 15 (depends on 14) The vehicle of claim 14, wherein the flying capacitor is coupled between a top junction between the first and second switch and a second junction between the third and fourth switch and the inductor is coupled between a positive input terminal and a middle point between the second and third switch. ### Claim 16 (depends on 15) The vehicle of claim 15, where the controller is further configured to, alternately flow the inductor current into the flying capacitor and bus capacitor coupled in series by the switches, or flow the inductor current into the bus capacitor, while the flying capacitor is coupled in series with the bus capacitor by the switches and bypassed by a diode. ### Claim 17 (depends on 15) The vehicle of claim 15, where the controller is further configured to, in response to the flying capacitor and the bus capacitor being coupled in parallel, operate, in a steady-state, the switches such that the first, second and fourth switches conduct and the third switch is turned off. ### Claim 18 (depends on 13) The vehicle of claim 13, wherein the switches are insulated gate bipolar junction transistors (IGBTs) or metal oxide semiconductor field effect transistors (MOSFETs).