Methods and systems for integrated Volt/VAr control in electric network

• US 10,135,247 B2
• Filed: 10/17/2013
• Issued: 11/20/2018
• Est. Priority Date: 10/17/2013
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Fisher, Rayette Ann, Ren, Wei, Satya, Murali Mohan Baggu Datta Venkata, Viana, Felipe Antonio Chegury, Anaparthi, Krishna Kumar, Walling, Reigh Allen
• Primary Examiner(s): Von Buhr, M. N.
• Application Number:
  US14/056,400
• Publication Number:
  US 20150112496A1
• Time in Patent Office: 1,860 Days
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00024 by means of mobile telephony
• CPC Class Codes: H02J 13/00028 involving the use of Internet protocols
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/1842 wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 40/20 Active power filtering [APF]
• CPC Class Codes: Y02E 40/30 Reactive power compensation
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/00 Systems supporting electrical power generation, transmission or distribution
• CPC Class Codes: Y04S 10/123 the energy generation units being or involving renewable energy sources
• CPC Class Codes: Y04S 10/22 Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units
• CPC Class Codes: Y04S 20/221 General power management systems
• CPC Class Codes: Y04S 20/222 : Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/124 : using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/126 : using wireless data transmission
• CPC Class Codes: Y04S 40/20 : Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A method and system for use in controlling an electric network are provided. The system includes an Integrated Volt-VAr Control (IVVC) component configured to determine optimization parameters for slow dynamics electromechanical devices and fast dynamics DER devices coupled to the network. The slow dynamics devices are controlled by a present state of the electric network and a voltage rise table that is adaptively updated in real-time using a command output, or a power flow-based complete optimization routine that generates optimal setpoints for the traditional controllable assets and for at least some of the fast dynamics DER devices. The fast dynamics devices are controlled locally using a control algorithm that uses a reactive power contribution based on IVVC settings, based on photo-voltaic (PV) plant active power variations, based on power factor, or based on a voltage of the local electric network.

Claims

1. A system for use in controlling an electric network comprising a plurality of slow dynamics electromechanical devices and a plurality of fast dynamics Distributed Energy Resource (DER) devices configured for relatively fast and continuous dynamic variation of a reactive power output, said system comprising:

an Integrated Volt-VAr Control (IVVC) component configured to determine one or more optimization parameters for the plurality of slow dynamics electromechanical devices and the plurality of fast dynamics DER devices each including an inverter which regulates a DER reactive power,

wherein the slow dynamics devices are configured to be controlled by a present state of the electric network and a voltage rise table that is adaptively updated in real-time using at least one of a command output and a power flow-based complete optimization routine for generating optimal setpoints for the slow dynamics devices and for at least some of the fast dynamics DER devices, wherein the voltage rise table is a look-up table representing voltage variations due to power injections,

wherein the fast dynamics DER devices are configured to be controlled locally between a remote control update using at least one of a control algorithm using a DER reactive power contribution based on IVVC settings, a control algorithm using a DER reactive power contribution based on variable generation DER active power variations, a control algorithm using a DER reactive power contribution based on power factor, and a control algorithm using a DER reactive power contribution based on a voltage of the local electric network.

2. The system of claim 1, wherein the slow dynamics electromechanical devices include at least one of a load tap changing transformer or autotransformer, a step-voltage regulator, and a switched capacitor bank.

3. The system of claim 1, wherein fast dynamics DER devices include at least one of a photovoltaic generator, a synchronous generator, a battery energy storage, a static synchronous compensator (STATCOM), a flexible AC transmission system (FACTS) device, and a static VAR compensator (SVC).

4. The system of claim 1, wherein the reactive power output of the fast dynamics DER devices is discretized in to linear steps to include in the voltage rise table or the power flow based optimization routine.

5. The system of claim 1, wherein the control algorithm using a DER reactive power contribution based on IVVC settings determines a reactive power setting based directly on a variable generation DER setting provided by IVVC optimization for a next time period of a plurality of time periods.

6. The system of claim 1, wherein the control algorithm using a DER reactive power contribution based on the voltage of the local electric network determines a voltage regulation set point from an IVVC optimization at a point of interconnection where fast dynamics DER devices are connected, and wherein the voltage regulation set point is determined for each hour.

7. The system of claim 1, wherein the control algorithm using a DER reactive power contribution based on power factor determines the power factor pf_i at the start of the ith hour as:

8. The system of claim 7, wherein the Qrefi is calculated by:

9. The system of claim 8, wherein intra-hour reactive power contribution of fast dynamics DER devices is obtained as the following equation:

10. An electric network control system comprising:

a network model component comprising a model of electrical components electrically coupled to form an electrical transmission and distribution network;

a measurement component configured to receive, from a plurality of sensors, data relating to measured parameters of the network and configured to determine a present state of the electric network;

a historian component configured to receive the sensor data and store at least some of the sensor data;

an estimator component configured to determine an estimate of a system load on the electric network and an estimate of generation of renewable sources coupled to the electric network using the at least some of the sensor data;

an integrated Volt-VAr control (IVVC) component configured to determine one or more optimization parameters for slow dynamics devices and fast dynamics devices coupled to the electric network, wherein the slow dynamics devices are configured to be operable at a single value of the one or more optimization parameters for a relatively long time period compared to a relatively short time period that the fast dynamics devices are operable at a single value of the one or more optimization parameters, wherein each of the fast dynamics devices includes an inverter which regulates the reactive power; and

a dispatch command component configured to;

receive the optimization parameters;

determine at least one of an optimal commitment for capacitor bank devices, distributed energy resource (DER) reactive power baseline values, and tap settings for voltage regulator and load tap changers (LTC), and

issue a dispatch message to the slow dynamics devices and the fast dynamics devices connected to the electric network.

11. The system of claim 10, wherein said IVVC component further comprises an adaptive closed loop voltage rise table updater configured to:

receive the issued dispatch messages and the present electric network state information; and

generate a voltage rise table for the electric network that is adaptively updated in real-time.

12. The system of claim 11, wherein said voltage rise table updater is configured to receive present electric network state information from a Supervisory Control and Data Acquisition (SCADA) system communicatively coupled to the electric network.

13. The system of claim 10, wherein said IVVC component further comprises a local fast dynamics device controller, said fast dynamics device controller comprising at least one of a control algorithm using a DER Reactive power contribution based on IVVC settings, a control algorithm using a DER Reactive power contribution based on photo-voltaic (PV) plant Active Power variations, a control algorithm using a DER Reactive power contribution based on power factor, and a control algorithm using a DER Reactive power contribution based on local electric network voltage.

14. The system of claim 13, wherein at least one of said algorithms receives a DER current setting for the DER reactive power contribution.