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

Patent metadata

Field	Value
Publication number	US-10135247-B2
Application number	US-201314056400-A
Country	US
Kind code	B2
Filing date	Oct 17, 2013
Priority date	Oct 17, 2013
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

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.

First claim

The invention claimed is:

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:

p
⁢

⁢

f
i

=

cos
⁡

(

tan

-
1

⁡

(

Q

ref

⁢
i

P

PV

⁢
i

)

)

where Qrefi is baseline reactive power output and P PV i is active power output at the start of the ith hour.

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

PVpos

ref

⁢
i

=

±

(

1
-
n

n

)

wherein

Q

ref

⁢
i

=

PVpos

ref

⁢
i

×

(

KVA
2

-

P
PV

⁢

i
2

)

and where n is number of steps of inverter response of the inverter and KVA is the inverter rating.

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

Q

PV
⁢

c

=

Q

Assignees

• Gen Electric

Inventors

• Fisher Rayette Ann
• Ren Wei
• Satya Murali Mohan Baggu Datta Venkata
• Viana Felipe Antonio Chegury
• Anaparthi Krishna Kumar
• Walling Reigh Allen

Classifications

• H02J2103/30

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

• H02J2101/24

  Photovoltaics · CPC title

• H02J13/1337

  involving the use of Internet protocols · CPC title

• H02J13/1333

  by means of mobile telephony · CPC title

• H02J13/1321

  using a wired telecommunication network or a data transmission bus · CPC title