Charging/discharging system for solar light power generator in smart grid environment with real-time pricing, duplex convertor of charging/discharging system, and charging/discharging method for solar light power generator

• US 9,236,638 B2
• Filed: 12/08/2011
• Issued: 01/12/2016
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Jung, Hyun Chul
• Primary Examiner(s): Berhanu, Samuel
• Application Number:
  US13/314,406
• Publication Number:
  US 20120153888A1
• Time in Patent Office: 1,496 Days
• Field of Search: 320/101, 320/103
• US Class Current: 1/1
• CPC Class Codes: H01M 10/465 with solar battery as charging system
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• CPC Class Codes: H02J 3/008 involving trading of energy or energy transmission rights
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y04S 50/10 Energy trading, including energy flowing from end-user application to grid

Abstract

Provided are a charging and discharging system for a solar light power generator in a smart grid environment, a method of operating the same, and a duplex converter for charging and discharging electricity into/from a battery. The system includes: an electricity price monitoring part which collects electricity price information from an electric grid; an electricity charge amount monitoring part which collects electricity charge amount information of a battery; a charge and discharge determination part which determines whether electricity supplied from the electric grid is to be charged into the battery or whether electricity stored in the battery via the electric grid or the solar light power generator is to be discharged to the electric grid, based on the price information and the charge amount information; and a charging and discharging part including the battery, so that electricity is charged into or discharged from the battery based on the determination.

Claims

1. A charging and discharging system for a solar light power generator in a smart grid environment with real-time pricing, the charging and discharging system comprising:

an electricity price monitoring part which collects electricity price information from an electric grid;

an electricity charge amount monitoring part which collects electricity charge amount information of a battery of the charging and discharging system;

a charge and discharge determination part which determines, based on the collected electricity price information and the collected electricity charge amount information, whether electricity supplied from the electric grid is to be charged into the battery or whether electricity stored in the battery via at least one of the electric grid and the solar light power generator is to be discharged to the electric grid; and

a charging and discharging part which selectively performs one of charging the battery and discharging the battery based on the determination made by the charge and discharge determination part; and

a metering part which measures electricity usage based on an amount of electricity charged into the battery and an amount of electricity discharged from the battery and which calculates an electricity price based on the measured electricity usage.

2. The charging and discharging system of claim 1, wherein the electricity price monitoring part collects electricity price information that varies with time from the electric grid, and the metering part calculates the electricity price based on the collected electricity price information that varies with time.

3. The charging and discharging system of claim 2, wherein when the electricity is charged into the battery, the metering part performs a forward measurement based on the amount of the charged electricity, and when the electricity is discharged from the battery, the metering part performs a backward measurement based on the amount of the discharged electricity, and the metering part measures the amount of electricity so that the electricity price is calculated differently depending on the collected electricity price information that varies with time.

4. The charging and discharging system of claim 1, wherein the electricity price monitoring part collects electricity price information varying with time from the electric grid, and the charge and discharge determination part determines to discharge the electricity stored in the battery when the collected electricity price information varying with time is larger than a preset value, and determines to charge the battery with the electricity when the collected electricity price information is smaller than or equal to a preset value.

5. The charging and discharging system of claim 4, wherein the charge and discharge determination part determines whether the electricity is to be charged into the battery or is to be discharged from the battery by calculating an average value of collected electricity price information varying with time for a preset period and comparing the average value to a present electricity price.

6. The charging and discharging system of claim 1, wherein the charging and discharging part adjusts a rate of discharge when the electricity is discharged from the battery.

7. The charging and discharging system of claim 1, wherein the charge and discharge determination part determines, based on the collected electricity price information and the collected electricity charge amount information, whether electricity stored in the battery via the electric grid is to be discharged to the electric grid.

8. A method of charging and discharging electricity into/from a battery of a charging and discharging part of a charging and discharging system for a solar light power generator in a smart grid environment with real-time pricing, the method comprising:

receiving electricity price information from an electric grid;

receiving electricity charge amount information of the battery;

determining whether electricity is to be purchased from the electric grid or whether electricity stored in the battery via at least one of the electric grid and the solar light power generator is to be sold to the electric grid, based on the received electricity price information and the received electricity charge amount information; and

;

selectively performing one of charging and discharging the battery, based on a result of the determining; and

measuring electricity usage based on an amount of electricity charged into the battery and an amount of electricity discharged from the battery and calculating an electricity price based on the measured electricity usage.

9. The method of claim 8, wherein the received electricity price information varies with time.

10. A computer readable recording medium having recorded thereon a program executable by a computer for performing the method of claim 8.