System and Method for Controlling Charging and Discharging of Electric Vehicle

Patent metadata

Field	Value
Publication number	US-2016159239-A1
Application number	US-201414905282-A
Country	US
Kind code	A1
Filing date	Sep 10, 2014
Priority date	Dec 2, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

A method for controlling charging and discharging of an electric vehicle, the method comprising: first, analyzing information such as the battery status and the history default rate of electric vehicles applying for joining a power-grid charging and discharging service, and screening out an electric vehicle that can participate in the charging and discharging service for electric vehicles in the future; then, determining an optimal combination state of a generator set and the electric vehicle by using a method of electric energy transmission cost comparison; and further monitoring in real time the status of the electric vehicle during charging and discharging, and performing real-time power control on the electric vehicle, whereby an electric vehicle aggregator not only can meet the requirements on the charging and discharging service of the power system, but also can implement energy management and real-time control of the electric vehicles during charging and discharging, thereby reducing the effect of charging and discharging on the vehicle-mounted power battery.

First claim

What is claimed is:

1 . A charging and discharging control system for an electric vehicle, characterized in that it includes a total control platform and a detecting module;
said total control platform including a communication module, a data storage and management module, a dual-level optimization control module, and a power distribution control module; said communication module for achieving two-way interaction between the total control platform and the electric vehicle, transmitting requirements for a charging and discharging service to a user of the electric vehicle, transmitting the total control platform willingness of the electric vehicle to participate in the charging and discharging service and real-time data about battery status, and performing data transmission and communication with a power control module in a charger; said data storage and management module for storing and managing data related to charging and discharging of the electric vehicle, assigning power command values about charging and discharging of the electric vehicle to related interface variables by protocol to be invoked by the total control platform; said dual-level optimization control module for determining in real time start-stop and power output conditions of a generator set in a wide-area power system, computing in real time decision variables of charging and discharging power of the electric vehicle which participates in a grid charging and discharging service, determining a number of electric vehicles which participate in the charging and discharging service and a real-time charging and discharging power by integrating and analyzing decision variables and data of the generator set; said power distribution control module for controlling the charging and discharging power of the electric vehicle after receiving power control commands from the communication module; said detecting module for detecting in real time power battery state of the electric vehicle connected to the grid and sending detection data to the total control platform through the communication module.

2 . A method for controlling charging and discharging of an electric vehicle, characterized in that it includes steps of:
Step 1: reading in real time load conditions of each load point in a wide-area power system, analyzing electrical energy demand of the wide-area power system in a next period of time; reading in real time related data of an electric vehicle which is willing to participate in a charging and discharging service of a power system, and storing and managing data through a data storage and management module; Step 2: determining a total cost of transfer of electrical energy from a generator set i to a wide area network during a period of time t; Step 3: determining a total cost of participation of an electric vehicle j in the charging and discharging service and screening out a dispatchable electric vehicle aggregator; Step 4: obtaining a combination of the generator set and the electric vehicle which participates in the charging and discharging service according to Step 2 and Step 3; Step 5: reading in real time data related to a power battery of the electric vehicle which participates in the charging and discharging service and calculating charging and discharging command values of the electric vehicle which participates in a grid charging and discharging service; and Step 6: storing and then outputting charging and discharging power commands of the electric vehicle which participates in the charging and discharging service.

3 . The method for controlling charging and discharging of an electric vehicle as recited in claim 2 , characterized in that in Step 1, the related data of the electric vehicle comprises:
default rates of an electric vehicle which participated in the charging and discharging service in the past, network topology points where the electric vehicle is connected to the power system, charging and discharging energy demand acceptable to the electric vehicle, rated power of a vehicle-mounted power battery of the electric vehicle, controllable status values, maximum allowable operating power scale values, charge state values, maximum allowable discharging power and maximum allowable charging power, wherein the maximum allowable discharging power and the maximum allowable charging power are both the maximum allowable operating power; when the charging and discharging energy demand of the electric vehicle has a positive value, it indicates that the electric vehicle is willing to participate in a charging service, and at this time said maximum allowable operating power is the maximum allowable charging power; and when the charging and discharging energy demand of the electric vehicle has a negative value, it indicates that the electric vehicle is willing to participate in a discharging service, and at this time said maximum allowable operating power is the maximum allowable charging power.

4 . The method for controlling charging and discharging of an electric vehicle as recited in claim 2 , characterized in that said Step 2 specifically includes substeps of:
Step 21: monitoring in real time running status of the generator set and measuring whether the generator set i can participate in power dispatching in a future period of time t; Step 22: determining a fuel cost C fi g (p i (t)) of the generator set i based on historical data on power generation efficiency and fuel cost of the generator set; Step 23: determining an emission cost C ei g (p i (t)) of the generator set i based on historical data on carbon emission factor and carbon emission cost of the generator set; Step 24: measuring and dispatching network loss of electric quantity p i (t) during the process of transmission through simulation of transmission from the generator set i to load points of wide area network, further calculating a cost of network loss C li g (p i (t)); Step 25: determining a total cost C j g (p j (t)) of transmission of electrical energy from the generator set i to wide area network during the period of time t based on the fuel cost, emission cost, and network loss cost of the generator set, the total cost having functions of:

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Assignees

• State Grid Chongqing Electric Power Co Electric Power Res Inst
• State Grid Corp China

Inventors

• Shi Lefeng
• Liu Zhengfa
• Hou Xingzhe
• Liu Yongxiang
• Gong Lin
• Wang Huicai
• Yang Zewei

Classifications

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title

• H02J13/1337 Primary

  involving the use of Internet protocols · CPC title

• Y04S10/126

  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 title

• Y04S10/14

  Energy storage units · CPC title