Method and device for charging electric vehicle in power system

• US 9,573,481 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:
  US14/461,335
• Publication Number:
  US 20150145477A1
• Time in Patent Office: 921 Days
• Field of Search: 320108-115
• US Class Current: 1/1
• CPC Class Codes: B60L 55/00 Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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: 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]

Abstract

A method and a device for charging an electric vehicle in a power system are provided. The method includes: obtaining a first electric vehicle connected to the power system, and obtaining a rated charging power and a first charging requirement; determining a first charging period corresponding to the first electric vehicle; determining a forecast period, and obtaining a second electric vehicle to be connected to the power system; revising the first charging period to obtain a second charging period, and obtaining a second charging requirement and a maximum charging power; establishing a charging model, 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 so as to charge each first electric vehicle under the optimal charging power.

Claims

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

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

determining a first charging period corresponding to the first electric vehicle;

determining a forecast period, and obtaining a second electric vehicle to be connected to the power system in the forecast period, in which the forecast period is less than or equal to the first charging period;

revising the first charging period to obtain a second charging period, and obtaining a second charging requirement and a maximum charging power of each second electric vehicle at each charging time in the second charging period respectively;

establishing a charging model of the first electric vehicle and the second electric vehicle in the second charging period, establishing a first constraint of the charging model according to the rated charging power and the first charging requirement at the dispatching time of each first electric vehicle, and establishing a second constraint of the charging model according to the second charging requirement and the maximum charging power at each charging time in the second charging period of each second electric vehicle; 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 second charging period, and sending the optimal charging power at the dispatching time to each first electric vehicle so as to charge each first 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 first charging period corresponding to the first electric vehicle comprises:

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

3. The method according to claim 2, wherein revising the first charging period to obtain a second charging period comprises:

selecting a second latest departure time from departure times when each first electric vehicle and each second electric vehicle leave the power system, and extending the first charging period to the second latest departure time to obtain the second charging period, in which each charging time in the second charging period is greater than or equal to the dispatching time and is less than or equal to the second latest departure time.

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

5. The method according to claim 1, wherein a connected time of each second electric vehicle is greater than the dispatching time, and is less than or equal to a time when the dispatching time is extended to the forecast period.

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

a first determining module, configured for determining a first charging period corresponding to the first electric vehicle;

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

a second obtaining module, configured for obtaining a second electric vehicle to be connected to the power system in the forecast period;

a revising module, configured for revising the first charging period to obtain a second charging period;

a third obtaining module, configured for obtaining a second charging requirement and a maximum charging power of each second electric vehicle at each charging time in the second charging period respectively;

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

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 second charging period; and

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

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

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

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

8. The device according to claim 7, wherein the revising module is further configured for:

selecting a second latest departure time from departure times when each first electric vehicle and each second electric vehicle leave the power system, and extending the first charging period to the second latest departure time to obtain the second charging period, in which each charging time in the second charging period is greater than or equal to the dispatching time and is less than or equal to the second latest departure time.

9. The device according to claim 6, wherein a connected time of each first electric vehicle is less than or equal to the dispatching time, the departure time of each first electric vehicle is greater than the dispatching time, and the first charging requirement at the dispatching time of each first electric vehicle is greater than 0.

10. The device according to claim 7, wherein a connected time of each second electric vehicle is greater than the dispatching time, and is less than or equal to a time when the dispatching time is extended to the forecast period.

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

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

determining a first charging period corresponding to the first electric vehicle;

determining a forecast period, and obtaining a second electric vehicle to be connected to the power system in the forecast period, in which the forecast period is less than or equal to the first charging period;

revising the first charging period to obtain a second charging period, and obtaining a second charging requirement and a maximum charging power of each second electric vehicle at each charging time in the second charging period respectively;

establishing a charging model of the first electric vehicle and the second electric vehicle in the second charging period, establishing a first constraint of the charging model according to the rated charging power and the first charging requirement at the dispatching time of each first electric vehicle, and establishing a second constraint of the charging model according to the second charging requirement and the maximum charging power at each charging time in the second charging period of each second electric vehicle; 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 second charging period, and sending the optimal charging power to each first electric vehicle, in which each first electric vehicle can charge power under the optimal charging power,

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