Method and device for charging electric vehicle in power system

• US 9,573,477 B2
• Filed: 08/15/2014
• Issued: 02/21/2017
• Est. Priority Date: 11/28/2013
• Status: Active Grant

• Current Assignee: Tsinghua University
• Original Assignee: Tsinghua University
• Inventors: Sun, Hongbin, Guo, Qinglai, Zhang, Boming, Wu, Wenchuan, Li, Zhengshuo, Xin, Shujun
• Primary Examiner(s): TAT, BINH C
• Application Number:
  US14/461,339
• Publication Number:
  US 20150145478A1
• Time in Patent Office: 921 Days
• Field of Search: 320108-116
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/14 by input of vehicle departure time
• CPC Class Codes: B60L 2260/50 by future state prediction
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/63 in response to network capacity
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

A method and a device for charging an electric vehicle in a power system are provided. The method includes: obtaining a plurality of electric vehicles connected to the power system at a dispatching time, and obtaining a rated charging power and a charging requirement at the dispatching time; determining a charging period corresponding to the plurality of electric vehicles; determining a forecast period, and obtaining a charging requirement, a remaining charging energy capacity and a maximum charging power; establishing a charging model of the plurality of electric vehicles, establishing a first constraint of the charging model, and establishing a second constraint of the charging model; and solving the charging model under the first constraint and the second constraint to obtain an optimal charging power of each electric vehicle at each charging time in the charging period so as to charge each electric vehicle under the optimal charging power.

Claims

1. A method for charging an electric vehicle in a power system, comprising:

obtaining a plurality of electric vehicles connected to the power system at a dispatching time, and obtaining a rated charging power and a charging requirement at the dispatching time of each electric vehicle respectively;

determining a charging period corresponding to the plurality of electric vehicles;

determining a forecast period, and obtaining a charging requirement, a remaining charging energy capacity and a maximum charging power at each charging time in the forecast period corresponding to a set of electric vehicles to be connected to the power system in the forecast period;

establishing a charging model of the plurality of electric vehicles, establishing a first constraint of the charging model according to the rated charging power and the charging requirement of each electric vehicle at the dispatching time, and establishing a second constraint of the charging model according to the charging requirement, the remaining charging energy capacity and the maximum charging power of the set at each charging time in the forecast period; and

solving the charging model under the first constraint and the second constraint to obtain an optimal charging power of each electric vehicle at each charging time in the charging period, and sending the optimal charging power at the dispatching time to each electric vehicle so as to charge each electric vehicle under the optimal charging power,

wherein the charging model is expressed according to formula (1),

2. The method according to claim 1, wherein determining a charging period corresponding to the plurality of electric vehicles comprises:

selecting a latest departure time from departure times when each electric vehicle leaves the power system, and taking a period which is from the dispatching time to the latest departure time as the charging period, in which each charging time in the charging period is greater than or equal to the dispatching time and is less than or equal to the latest departure time.

3. The method according to claim 2, wherein each charging time in the forecast period is greater than or equal to a next dispatching time and is less than or equal to the latest departure time.

4. The method according to claim 1, wherein a connected time of each electric vehicle is less than or equal to the dispatching time, the departure time of each electric vehicle is greater than the dispatching time, and the charging requirement at the dispatching time of each electric vehicle is greater than 0.

5. A device for charging an electric vehicle in a power system, comprising:

a non-transitory memory comprising instructions stored thereon;

a processor, configured by the instructions for performing and comprising;

a first obtaining module, configured for obtaining a plurality of electric vehicles connected to the power system at a dispatching time, and obtaining a rated charging power and a charging requirement of each electric vehicle at the dispatching time respectively;

a first determining module, configured for determining a charging period corresponding to the plurality of electric vehicles;

a second determining module, configured for determining a forecast period, in which the forecast period is less than or equal to the charging period;

a second obtaining module, configured for obtaining a charging requirement, a remaining charging energy capacity and a maximum charging power at each charging time in the forecast period corresponding to a set of electric vehicles to be connected to the power system in the forecast period;

an establishing module, configured for establishing a charging model of the plurality of electric vehicles, establishing a first constraint of the charging model according to the rated charging power and the charging requirement of each electric vehicle at the dispatching time, and establishing a second constraint of the charging model according to the charging requirement, the remaining charging energy capacity and the maximum charging power of the set at each charging time in the forecast period;

a solving module, configured for solving the charging model under the first constraint and the second constraint to obtain an optimal charging power of each electric vehicle at each charging time in the charging period; and

a sending module, configured for sending the optimal charging power at the dispatching time to each electric vehicle so as to charge each electric vehicle under the optimal charging power,

wherein the charging model is expressed according to formula (1),

6. The device according to claim 5, wherein the first determining module is further configured for:

selecting a latest departure time from departure times when each electric vehicle leaves the power system, and taking a period which is from the dispatching time to the latest departure time as the charging period, in which each charging time in the charging period is greater than or equal to the dispatching time and is less than or equal to the latest departure time.

7. The device according to claim 6, wherein each charging time in the forecast period is greater than or equal to a next dispatching time and is less than or equal to the latest departure time.

8. The device according to claim 5, wherein a connected time of each electric vehicle is less than or equal to the dispatching time, the departure time of each electric vehicle is greater than the dispatching time, and the charging requirement at the dispatching time of each electric vehicle is greater than 0.

9. A non-transitory computer readable storage medium, comprising a computer program for executing acts of:

obtaining a plurality of electric vehicles connected to the power system at a dispatching time, and obtaining a rated charging power and a charging requirement at the dispatching time of each electric vehicle respectively;

determining a charging period corresponding to the plurality of electric vehicles;

determining a forecast period, and obtaining a charging requirement, a remaining charging energy capacity and a maximum charging power at each charging time in the forecast period corresponding to a set of electric vehicles to be connected to the power system in the forecast period;

establishing a charging model of the plurality of electric vehicles, establishing a first constraint of the charging model according to the rated charging power and the charging requirement of each electric vehicle at the dispatching time, and establishing a second constraint of the charging model according to the charging requirement, the remaining charging energy capacity and the maximum charging power of the set at each charging time in the forecast period; and

solving the charging model under the first constraint and the second constraint to obtain an optimal charging power of each electric vehicle at each charging time in the charging period, and sending the optimal charging power at the dispatching time to each electric vehicle so as to charge each electric vehicle under the optimal charging power,

wherein the charging model is expressed according to formula (1),