# US 10,483,836 B2 · Method of early hard switching detection and protection for inductive power transfer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,483,836 B2 - Document ID: US10483836B2 - Status: Granted - Kind: B2 - Application number: 15/663,989 - Filed: 2017-07-31 - Published: 2019-01-31 - Granted: 2019-11-19 - Earliest claimed: 2017-07-31 - Assignees: Lear Corporation - Applicants: Lear Corporation - Inventors: Kendall Eggers - Web page: https://patentgrep.com/patent/US10483836B2 ## CPC - H02M 1/083: {for the ignition at the zero crossing of the voltage or the current} - B60L 53/122: Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil - B60L 53/124: Detection or removal of foreign bodies - B60L 53/126: Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver - H02J 50/12: of the resonant type - H02M 3/01: {Resonant DC/DC converters} - H02M 3/33507: {with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence)} - H02M 3/33573: {Full-bridge at primary side of an isolation transformer} - H02M 1/0058: {by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826)} - H02M 3/33571: {Half-bridge at primary side of an isolation transformer} - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 90/14: Plug-in electric 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) - 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 - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An inductive power transfer system includes a power converter and a controller. The power converter includes switches. The controller to switch the switches according to a schedule to cause the power converter to output a voltage and a current to a resonant network. The controller to compare a zero-current crossover point of the current and the schedule to determine whether the zero-current crossover point occurs prior to a scheduled time that one or more of the switches are be switched. The controller to disable the switches from switching when the zero-current crossover point occurs prior to the scheduled time such that the switches do not switch at the scheduled time thereby preventing hard switching of the switches from occurring. ## Claims ### Claim 1 A system for inductive power transfer, the system comprising: a power converter including a plurality of switches; a controller programmed with a schedule having scheduled times of when the switches are to be switched for the power converter to output a voltage and a current to a resonant network and the controller knowing the schedule in advance of when the switches are to be switched according to the schedule, the controller to switch the switches according to the schedule to cause the power converter to output the voltage and the current to the resonant network; and the controller to compare a zero-current crossover point of the current and the schedule to determine whether the zero-current crossover point occurs prior to a scheduled time of the schedule that one or more of the switches are be switched and to disable the switches from switching, at least at the scheduled time, when the zero-current crossover point occurs prior to the scheduled time such that the switches do not switch at the scheduled time thereby preventing hard switching of the switches from occurring. ### Claim 2 (depends on 1) The system of claim 1 wherein: the controller to confirm that soft switching of the one or more of the switches is occurring when the zero-current crossover point occurs after the scheduled time that the one or more of the switches are switched. ### Claim 3 (depends on 1) The system of claim 1 wherein: the scheduled time includes a start time that the one or more of the switches are switched on and an end time that the one or more of the switches are switched off. ### Claim 4 (depends on 1) The system of claim 1 wherein: the power converter includes a full-bridge circuit having four switches. ### Claim 5 (depends on 1) The system of claim 1 wherein: the power converter includes a half-bridge circuit having two switches. ### Claim 6 (depends on 1) The system of claim 1 wherein: the switches are transistor switches. ### Claim 7 (depends on 1) The system of claim 1 wherein: the switches are MOSFET switches. ### Claim 8 A method for inductive power transfer for use with a power converter including a plurality of switches, the method comprising: programming a controller with a schedule having scheduled times of when the switches are to be switched for the power converter to output a voltage and a current to a resonant network such that the controller knows the schedule in advance of when the switches are to be switched according to the schedule; switching, by the controller, the switches of the power converter according to the schedule; comparing a zero-current crossover point of the current and the schedule and detecting that the zero-current crossover point occurs prior to a scheduled time of the schedule that one or more of the switches are be switched; and disabling the switches from switching, at least at the scheduled time, in response to the zero-current crossover point occurring prior to the scheduled time such that the switches do not switch at the scheduled time thereby preventing hard switching of the switches from occurring. ### Claim 9 (depends on 8) The method of claim 8 further comprising: confirming that soft switching of the one or more of the switches is occurring when the zero-current crossover point occurs after the scheduled time that the one or more of the switches are switched. ### Claim 10 (depends on 8) The method of claim 8 wherein: the scheduled time includes a start time that the one or more of the switches are switched on and an end time that the one or more of the switches are switched off.