# US 2014/0152225 A1 · Electric Drive System and Energy Management Method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152225 A1 - Document ID: US20140152225A1 - Status: Published application - Kind: A1 - Application number: 14/094,086 - Filed: 2013-12-02 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Jian Zhou; Fei Xu; Dong Liu; Hai Qiu; Pengju Kang - Web page: https://patentgrep.com/patent/US20140152225A1 ## CPC - B60L 7/18: Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - B60L 15/2081: {for drive off on a slope} - B60L 15/209: {for overtaking} - B60L 15/38: with automatic control - B60L 50/30: using propulsion power stored mechanically, e.g. in fly-wheels - B60L 50/40: using propulsion power supplied by capacitors - B60L 50/51: characterised by AC-motors - B60L 50/64: Constructional details of batteries specially adapted for electric vehicles - B60L 58/20: having different nominal voltages - H02J 7/02: for charging batteries from AC mains by converters - H02K 17/02: Asynchronous induction motors - H02P 4/00: Arrangements specially adapted for regulating or controlling the speed or torque of electric motors that can be connected to two or more different electric power supplies (vector control H02P21/00) - B60L 2240/421: Speed - B60L 2240/423: Torque - H02J 7/345: {using capacitors as storage or buffering devices} - 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 - Y02T 90/16: Information or communication technologies improving the operation of electric vehicles - 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 - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An electric drive system includes an energy storage system (ESS), a power conversion system, and an alternating current (AC) traction system. The ESS provides or receives electric power. The ESS includes a first energy storage unit and a second energy storage unit. The power conversion system is electrically coupled to the ESS for converting an input power to an output power. The AC traction system is electrically coupled to the power conversion system for converting the output power of the power conversion system to mechanical torques. The AC traction system includes a first AC drive device and a second AC drive device. An energy management system (EMS) is in electrical communication with the ESS, the AC traction system, and the power conversion system for providing control signals. ## Claims ### Claim 1 An electric drive system, comprising: an energy storage system (ESS), comprising: a first energy storage unit configured for providing or receiving a first power; and a second energy storage unit configured for providing or receiving a second power; a power conversion system electrically coupled to the ESS for converting an input power to an output power, wherein the power conversion system comprises a power conversion device, wherein the power conversion device comprises: a first terminal electrically coupled to the first energy storage unit; a second terminal electrically coupled to the second energy storage unit; a third terminal; and a fourth terminal; an alternating current (AC) traction system electrically coupled to the power conversion system for converting the output power of the power conversion system to mechanical torques, wherein the AC traction system comprises: a first AC drive device coupled to the third terminal of the power conversion device for providing or receiving a first mechanical torque; and a second AC drive device coupled to the fourth terminal of the power conversion device for providing or receiving a second mechanical torque; and an energy management system (EMS) in communication with the ESS, the AC traction system, and the power conversion system for providing control signals. ### Claim 2 (depends on 1) The electric drive system of claim 1, wherein the power conversion system further comprises: a pre-charging switching device electrically coupled between the first energy storage unit and the second energy storage unit for selectively providing a power flow path between the first energy storage unit and the second energy storage unit. ### Claim 3 (depends on 2) The electric drive system of claim 2, wherein the pre-charging switching device is a unidirectional switching device for providing a unidirectional power flow path for charging the second energy storage unit. ### Claim 4 (depends on 1) The electric drive system of claim 1, wherein the power conversion device is a single power conversion device. ### Claim 5 (depends on 1) The electric drive system of claim 1, wherein the power conversion device further comprises: a first power conversion device, the first power conversion device is electrically coupled to the first energy storage unit through the first terminal and electrically coupled to the first AC drive device through the third terminal; and a second power conversion device coupled in parallel with the first power conversion device, the second power conversion device is electrically coupled to the second energy storage unit through the second terminal and electrically coupled to the second AC drive device through the fourth terminal. ### Claim 6 (depends on 1) The electric drive system of claim 1, wherein the power conversion device further comprises: a first power conversion device electrically coupled to the first energy storage unit through the first terminal and electrically coupled to the second energy storage unit through the second terminal, and electrically coupled to the second AC drive device through the fourth terminal; and a second power conversion device coupled in series with the first power conversion device, the second power conversion device is electrically coupled to the first AC drive device through the third terminal. ### Claim 7 (depends on 1) The electric drive system of claim 1, wherein the first AC drive device comprises: at least one of an induction motor (IM) and an interior permanent motor (IPM) operated as a first AC motor; and a first DC/AC inverter electrically coupled to the first AC motor for providing AC power to the first AC motor, wherein the second AC drive device comprises: at least one of the IM and the IPM operated as a second AC motor; and a second DC/AC inverter electrically coupled to the second AC motor for providing AC power to the second AC motor. ### Claim 8 (depends on 1) The electric drive system of claim 1, wherein: the first AC drive device is configured to independently provide the first mechanical torque to a first load; and the second AC drive device is configured to independently provide the second mechanical torque to a second load. ### Claim 9 (depends on 1) The electric drive system of claim 1, further comprising a power split device mechanically coupled between the AC traction system and a load wherein the power split device comprises: a first mechanical terminal mechanically coupled to the first AC drive device for receiving a first mechanical torque provided from the first AC drive device; a second mechanical terminal mechanically coupled to the second AC drive device for receiving a second mechanical torque provided from the second AC drive device; and a third mechanical terminal mechanically coupled to the load for providing a third mechanical torque to the load, the third mechanical torque is a combination of the first mechanical torque and the second mechanical torque by the power split device. ### Claim 10 (depends on 9) The electric drive system of claim 9, wherein the power split device is configured for splitting a third mechanical torque into a first mechanical torque and a second mechanical torque, wherein: the third mechanical terminal is configured for receiving the third mechanical torque from the load; the first mechanical terminal is configured for providing the first mechanical torque which is converted into electric power for charging the ESS; and the second mechanical terminal is configured for providing the second mechanical torque which is converted into electric power for charging the ESS. ### Claim 11 (depends on 9) The electric drive system of claim 9, wherein the power split device is configured for splitting a first mechanical torque into a second Mechanical torque and a third mechanical torque, wherein: the first mechanical terminal is configured for receiving the first mechanical torque provided from the first AC drive device; the second mechanical terminal is configured for providing the second mechanical torque to the second AC drive device and converting the second mechanical torque into electric power for charging the ESS; and the third mechanical terminal is configured for providing the third mechanical torque to the load. ### Claim 12 (depends on 9) The electric drive system of claim 9, further comprising: a transmission device mechanically coupled between the AC traction system and the power split device for matching output speed of the AC traction system with an electric drive system speed. ### Claim 13 An energy management method, comprising: enabling at least one of a first AC drive device and a second AC drive device based at least in part on an electric drive system speed signal; enabling at least one of a first energy storage unit and a second energy storage unit; and sending power control signals to a power conversion system for controlling power flow paths in an electric drive system, wherein controlling the power flow paths comprises: receiving or providing at least one input power by at least one of a first terminal and a second terminal of the power conversion system; and providing or receiving at least one output power by at least one of a third terminal and a fourth terminal of the power conversion system. ### Claim 14 (depends on 13) The method of claim 13, wherein controlling the power flow paths further comprises: converting an electric power generated from an energy storage system (ESS) into a first mechanical torque by the first AC drive device; splitting the first mechanical torque into a second mechanical torque and a third mechanical torque; providing the second mechanical torque to the second AC drive device and converting the second mechanical torque into electric power for charging a second energy storage unit; and providing the third mechanical torque to the load. ### Claim 15 (depends on 13) The method of claim 13, further comprising: calculating a first torque command signal and a second torque command signal through a torque distribution unit; and sending the first torque command signal and the second torque control signal to the first AC drive device and the second AC drive device, respectively. ### Claim 16 (depends on 13) The method of claim 13, further comprising: determining an operating mode of a propulsion system based at least in part on the electric drive system speed, wherein the operating mode comprises: a normal mode comprising a starting mode, an accelerating, a cruising mode, and a braking mode; and a fault-tolerate mode. ### Claim 17 (depends on 16) The method of claim 16, further comprising one of the following: enabling at least one of the first AC drive device and second AC drive device and at least one of the first energy storage unit and second energy storage unit in the fault-tolerate mode; enabling the second AC drive device when a required power Preq is within the ability of the second AC drive device in the starting mode; enabling the first AC drive device when Preq the ability of the second AC drive device in the starting mode; enabling both of the first AC drive device and second AC drive device in the accelerating mode; enabling at least one of the first AC drive device and second AC drive device in the cruising mode; and enabling both of the first AC drive device and second AC drive device in the braking mode. ### Claim 18 (depends on 15) The method of claim 15, wherein the torque distribution unit comprises a torque distribution algorithm with a look up table defining high efficiency areas of two AC motors according to efficiency maps of each AC motor in the first AC drive device and the second AC drive device for reducing total loss. ### Claim 19 (depends on 18) The method of claim 18, further comprising changing an operating point of the first AC drive device through a transmission device for optimizing the torque distribution algorithm. ### Claim 20 (depends on 13) The method of claim 13, further comprising: enabling the second energy storage unit as an assistant to provide additional power when the first energy storage unit fails to provide a required power.