Grid tied system controller including logic coupled to a photovoltaic station and an energy storage system

Patent metadata

Field	Value
Publication number	US-9843189-B2
Application number	US-201514714933-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	May 19, 2014
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A battery energy storage system control system, including: logic coupled to a photovoltaic station and an energy storage system and executing a photovoltaic station capacity firming algorithm operable for making a combined output of the photovoltaic station and the energy storage system substantially constant such that power swings on an associated feeder system are avoided; logic coupled to the photovoltaic station and the energy storage system and executing a voltage support algorithm operable for holding point of common coupling voltage and phase values substantially equal to substation voltage and phase values via power injection or removal; and logic coupled to the photovoltaic station and the energy storage system and executing an energy time shift algorithm operable for storing energy during periods of relatively low demand and providing energy during periods of relatively high demand.

First claim

What is claimed is:

1. A battery energy storage system control system, comprising:
logic coupled to a photovoltaic station and an energy storage system and executing a photovoltaic station capacity firming algorithm operable for making a combined output of the photovoltaic station and the energy storage system substantially constant such that power swings on an associated feeder system are avoided;
logic coupled to the photovoltaic station and the energy storage system and executing a voltage support algorithm operable for holding point of common coupling voltage and phase values substantially equal to substation voltage and phase values via power injection or removal; and
logic coupled to the photovoltaic station and the energy storage system and executing an energy time shift algorithm operable for storing energy during periods of relatively low demand and providing energy during periods of relatively high demand, wherein the energy time shift algorithm calculates a probable time of peak load on a given feeder based on historical data and begins energy storage system discharge at a corresponding predetermined time before the calculated probable time of peak load to ensure peak load shaving, wherein the energy time shift algorithm calculates a time to commence energy storage system discharge such that a load curve maximum of a previous predetermined time period corresponds with a middle time of a discharge time interval utilized.

2. The system of claim 1 , wherein the photovoltaic station capacity firming algorithm derives an optimal reference power output curve from historical data.

3. The system of claim 2 , wherein the energy storage system supplements power output of the photovoltaic station to substantially match the optimal reference power output curve.

4. The system of claim 1 , wherein the photovoltaic station capacity firming algorithm comprises intermittency detection logic that idles the energy storage system when a power output of the photovoltaic station is sufficiently constant.

5. The system of claim 1 , wherein the voltage support algorithm monitors the point of common coupling voltage and phase values and the substation voltage and phase values in real time.

6. A battery energy storage system control method, comprising:
making a combined output of the photovoltaic station and the energy storage system substantially constant such that power swings on an associated feeder system are avoided via logic coupled to a photovoltaic station and an energy storage system using a photovoltaic station capacity firming algorithm;
holding point of common coupling voltage and phase values substantially equal to substation voltage and phase values via power injection or removal via logic coupled to the photovoltaic station and the energy storage system using a voltage support algorithm; and
storing energy during periods of relatively low demand and providing energy during periods of relatively high demand via logic coupled to the photovoltaic station and the energy storage system using an energy time shift algorithm, wherein the energy time shift algorithm calculates a probable time of peak load on a given feeder based on historical data and begins energy storage system discharge at a corresponding predetermined time before the calculated probable time of peak load to ensure peak load shaving, wherein the energy time shift algorithm calculates a time to commence energy storage system discharge such that a load curve maximum of a previous predetermined time period corresponds with a middle time of a discharge time interval utilized.

7. The method of claim 6 , wherein the photovoltaic station capacity firming algorithm derives an optimal reference power output curve from historical data.

8. The method of claim 7 , wherein the energy storage system supplements power output of the photovoltaic station to substantially match the optimal reference power output curve.

9. The method of claim 6 , wherein the photovoltaic station capacity firming algorithm comprises intermittency detection logic that idles the energy storage system when a power output of the photovoltaic station is sufficiently constant.

10. The method of claim 6 , wherein the voltage support algorithm monitors the point of common coupling voltage and phase values and the substation voltage and phase values in real time.

11. An energy delivery system, comprising:
a photovoltaic station;
an energy storage system;
logic coupled to the photovoltaic station and the energy storage system and executing a photovoltaic station capacity firming algorithm operable for making a combined output of the photovoltaic station and the energy storage system substantially constant such that power swings on an associated feeder system are avoided;
logic coupled to the photovoltaic station and the energy storage system and executing a voltage support algorithm operable for holding point of common coupling voltage and phase values substantially equal to substation voltage and phase values via power injection or removal; and
logic coupled to the photovoltaic station and the energy storage system and executing an energy time shift algorithm operable for storing energy during periods of relatively low demand and providing energy during periods of relatively high demand, wherein the energy time shift algorithm calculates a probable time of peak load on a given feeder based on historical data and begins energy storage system discharge at a corresponding predetermined time before the calculated probable time of peak load to ensure peak load shaving, wherein the energy time shift algorithm calculates a time to commence energy storage system discharge such that a load curve maximum of a previous predetermined time period corresponds with a middle time of a discharge time interval utilized.

12. The system of claim 11 , wherein the photovoltaic station capacity firming algorithm derives an optimal reference power output curve from historical data.

13. The system of claim 12 , wherein the energy storage system supplements power output of the photovoltaic station to substantially match the optimal reference power output curve.

14. The system of claim 11 , wherein the photovoltaic station capacity firming algorithm comprises intermittency detection logic that idles the energy storage system when a power output of the photovoltaic station is sufficiently constant.

15. The system of claim 11 , wherein the voltage support algorithm monitors the point of common coupling voltage and phase values and the substation voltage and phase values in real time.

Assignees

• Kamalasadan Sukumar
• Abdelrazek Sherif Abdelmageed
• Enslin Johan H R
• SOWDER Daniel Blair
• Univ North Carolina Charlotte
• Duke Energy Corp

Inventors

• Kamalasadan Sukumar
• Abdelrazek Sherif Abdelmageed
• Enslin Johan H R
• SOWDER Daniel Blair

Classifications

• H02J3/381

  Dispersed generators · CPC title

• Y02E40/10

  Flexible AC transmission systems [FACTS] · CPC title

• Y02E70/30

  Systems combining energy storage with energy generation of non-fossil origin · CPC title

• H02J2103/30

  Simulating, planning, modelling, reliability check or computer assisted design [CAD] of electric power networks · CPC title

• H02J2101/24

  Photovoltaics · CPC title