# US 12,109,896 B2 · Method of management of an electric propulsion system and electric propulsion system implementing the method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,896 B2 - Document ID: US12109896B2 - Status: Granted - Kind: B2 - Application number: 18/690,264 - Filed: 2022-08-02 - Published: 2024-08-15 - Granted: 2024-10-08 - Earliest claimed: 2021-09-08 - Assignees: Fpt Industrial S.P.A. - Applicants: Fpt Industrial S.P.A. - Inventors: Niccolò Nudda; Mattia Contardi - Web page: https://patentgrep.com/patent/US12109896B2 ## CPC - B60L 15/2054: {by controlling transmissions or clutches} - B60L 15/007: {Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles} - B60L 50/15: with additional electric power supply (with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61) - B60L 2240/486: Operating parameters - 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 ## Abstract Electric propulsion system comprising a first and a second propulsion line, operatively connectable individually to a common driving axle, each propulsion line comprising an electric motor, a gearbox comprising at least two gear ratios, a clutch to connect/disconnect the related propulsion line from the driving axle, processing means configured to control the interruption of torque delivery and consequent variation of the transmission ratio first in the propulsion line whose maximum deliverable torque is lower and, at the end of the variation of the transmission ratio, the interruption of torque delivery and consequent variation of the transmission ratio in the other propulsion line. ## Claims ### Claim 1 An electric propulsion system comprising a first and a second propulsion line, operatively connectable individually to a common driving axle, each propulsion line comprising an electric motor, a gearbox including at least two gear ratios, a clutch to connect/disconnect the related propulsion line from the driving axle, the system comprising processing means configured to distribute a requested torque between the first and second propulsion lines and to select, for each propulsion line, a relating transmission ratio and wherein when it is requested to vary the transmission ratio of both the first and second propulsion lines, the processing means are configured for commanding: interruption of the supply of driving torque and consequent variation of the transmission ratio, first in a first propulsion line which has a lower maximum deliverable torque between the two propulsion lines and, at the end of the variation of the transmission ratio, reactivation of the torque delivery of a first transmission line, interruption of torque delivery and consequent variation of the transmission ratio, in the other propulsion line and, at the end of the variation of the transmission ratio, and reactivation of the torque delivery of the other transmission line. ### Claim 2 (depends on 1) The electric propulsion system according to claim 1, wherein the processing means are configured so that when they control the interruption of the torque delivery of one of the two propulsion lines, they simultaneously control the other propulsion line to deliver the entire requested driving torque, limited to a maximum torque value that can be delivered by a single propulsion line. ### Claim 3 (depends on 1) The electric propulsion system according to claim 1, wherein when it is requested to vary the transmission ratio of both the first and second propulsion lines and both the first and second propulsion lines deliver equal driving torque, then, as propulsion line delivering lower driving torque, one of the two propulsion lines according to a predetermined criterion is selected. ### Claim 4 (depends on 3) The electric propulsion system according to claim 3, wherein the criterion is random or balanced. ### Claim 5 (depends on 2) The electric propulsion system according to claim 2, comprising the following steps in succession: selection of the propulsion line that has the highest deliverable driving torque, when the propulsion lines have a different maximum deliverable torque, or of one of the two propulsion lines according to a predetermined selection criterion, when the propulsion lines have an equal maximum deliverable drive torque; delivery of the entire requested driving torque by the selected propulsion line and variation of the transmission ratio by the other propulsion line; and delivery of the entire driving torque by the unselected propulsion line and variation of the transmission ratio by the selected propulsion line. ### Claim 6 (depends on 1) The electric propulsion system according to claim 1, wherein the processing means are configured to differentiate a torque delivered between the first and second propulsion lines to minimize a sum of the mechanical and electrical losses of the propulsion system. ### Claim 7 (depends on 6) The electric propulsion system according to claim 6, wherein the processing means comprise storage means in which one or more tables are stored which are arranged for returning a distribution ratio of the requested torque between the first and second propulsion lines and a relating transmission ratio as a function of the requested torque and a speed of rotation of the driving axle. ### Claim 8 (depends on 6) The electric propulsion system according to claim 6, wherein the storage means comprise a first table in which, as a function of the torque requested to the propulsion system and a rotation speed of the driving axle, it returns a value of distribution of the requested torque between the first and second lines and in which the table is arranged so that, a first zone contiguous with an axis of the requested torque, the torque requested to the propulsion system is equally divided between the first and second propulsion lines; a second zone contiguous with an axis of the rotation speed of the driving axle, the torque requested by the propulsion system is supplied only by one of the two propulsion lines, while the other propulsion line is deactivated and disconnected from the driving axle; a third zone contiguous with the second zone, the torque requested by the propulsion system is equally divided between the first and second propulsion lines; and a fourth zone delimited by two approximately linear curves that originate in the origin of the axles, the torque requested to the propulsion system is delivered differently between the two propulsion lines in order to minimize the electrical and mechanical losses of the propulsion system. ### Claim 9 (depends on 1) The electric propulsion system according to claim 1, wherein a residual available torque is a function of electro-mechanical characteristics of the electric motor of the transmission line and of the current temperature of the electric motor. ### Claim 10 (depends on 6) A method of generating a torque distribution and gear ratio selection scheme for each of the first and second propulsion lines of the propulsion system according to claim 6, wherein, for each requested torque value, for each value of rotation speed of the towing axle, identification of a predetermined number of distribution ratios of the requested torque between the two propulsion lines, considering all possible permutations due to the transmission ratios of the two propulsion lines, calculation of mechanical and electrical losses, and memorization of the permutation which allows to minimize the sum of mechanical and electrical losses. ### Claim 11 A method for controlling of an electric propulsion system comprising a first and a second propulsion line, operably connectable to a driving axle, each propulsion line comprising: an electric motor, a gearbox including at least two gear ratios a clutch to connect/disconnect the relating propulsion line from the driving axle, the method comprising a strategy of distributing a requested torque between the first and second propulsion lines and for selecting, for each propulsion line, a relating transmission ratio wherein when it is requested to vary the transmission ratio of both first and second propulsion lines, the method includes the following steps: interruption of the supply of driving torque and consequent variation of the transmission ratio, first in a first propulsion line which has a lower maximum deliverable torque between the two propulsion lines and, at the end of the variation of the transmission ratio, reactivation of the torque delivery from the first transmission line, interruption of torque delivery and consequent variation of the transmission ratio on the other propulsion line and, at the end of the variation of the transmission ratio, reactivation of the torque delivery of the other transmission line. ### Claim 12 (depends on 2) The electric propulsion system according to claim 2, wherein when it is requested to vary the transmission ratio of both the first and second propulsion lines and both the first and second propulsion lines deliver equal driving torque, then, as propulsion line delivering lower driving torque, one of the two propulsion lines according to a predetermined criterion is selected. ### Claim 13 (depends on 3) The electric propulsion system according to claim 3, comprising the following steps in succession: selection of the propulsion line that has the highest deliverable driving torque, when the propulsion lines have a different maximum deliverable torque, or of one of the two propulsion lines according to a predetermined selection criterion, when the propulsion lines have an equal maximum deliverable drive torque; delivery of the entire requested driving torque by the selected propulsion line and variation of the transmission ratio by the other propulsion line; delivery of the entire driving torque by the unselected propulsion line and variation of the transmission ratio by the selected propulsion line. ### Claim 14 (depends on 2) The electric propulsion system according to claim 2, wherein the processing means are configured to differentiate a torque delivered between the first and second propulsion lines to minimize a sum of the mechanical and electrical losses of the propulsion system. ### Claim 15 (depends on 3) The electric propulsion system according to claim 3, wherein the processing means are configured to differentiate a torque delivered between the first and second propulsion lines to minimize a sum of the mechanical and electrical losses of the propulsion system. ### Claim 16 (depends on 4) The electric propulsion system according to claim 4, wherein the processing means are configured to differentiate a torque delivered between the first and second propulsion lines to minimize a sum of the mechanical and electrical losses of the propulsion system. ### Claim 17 (depends on 5) The electric propulsion system according to claim 5, wherein the processing means are configured to differentiate a torque delivered between the first and second propulsion lines to minimize a sum of the mechanical and electrical losses of the propulsion system. ### Claim 18 (depends on 7) The electric propulsion system according to claim 7, wherein the storage means comprise a first table in which, as a function of the torque requested to the propulsion system and a rotation speed of the driving axle, it returns a value of distribution of the requested torque between the first and second lines and in which the table is arranged so that, a first zone contiguous with an axis of the requested torque, the torque requested to the propulsion system is equally divided between the first and second propulsion lines; a second zone contiguous with an axis of the rotation speed of the driving axle, the torque requested by the propulsion system is supplied only by one of the two propulsion lines, while the other propulsion line is deactivated and disconnected from the driving axle; a third zone contiguous with the second zone, the torque requested by the propulsion system is equally divided between the first and second propulsion lines; and a fourth zone delimited by two approximately linear curves that originate in the origin of the axles, the torque requested to the propulsion system is delivered differently between the two propulsion lines in order to minimize the electrical and mechanical losses of the propulsion system. ### Claim 19 (depends on 2) The electric propulsion system according to claim 2, wherein a residual available torque is a function of electro-mechanical characteristics of the electric motor of the transmission line and of the current temperature of the electric motor. ### Claim 20 (depends on 3) The electric propulsion system according to claim 3, wherein a residual available torque is a function of electro-mechanical characteristics of the electric motor of the transmission line and of the current temperature of the electric motor.