Distribution Operations - Voltage and Var Control (VVC) Function

Narrative
VVC Function During Scheduled Run
VVC Function During Event Run
VVC Function Participation in Severe Emergency in Bulk Power System with Intentional Islands

Narrative

This application calculates the optimal settings of voltage controller of LTCs, voltage regulators, DERs, power electronic devices, and capacitor statuses optimizing the operations by either following different objectives at different times, or considering conflicting objectives together in a weighted manner.

It supports three modes of operation:

1. Closed-loop mode, in which the application runs either periodically (e.g., every 15 min) or is triggered by an event (i.e., topology or objective change), based on real-time information. The application’s recommendations are executed automatically via SCADA control commands.

2. Study mode, in which the application performs “what-if” studies, and provides recommended actions to the operator.

3. Look-ahead mode, in which conditions expected in the near future can be studied (from 1 hour through 1 week) by the operator.

The following objectives, which could be preset for different times of the day and overwritten by operator if need to, are supported by the application:

a. Minimize kWh consumption at voltages beyond given voltage quality limits (i.e., ensure standard voltages at customer terminals)

b. Minimize feeder segment(s) overload

c. Reduce load while respecting given voltage tolerance (normal and emergency)

d. Conserve energy via voltage reduction

e. Reduce or eliminate overload in transmission lines

f. Reduce or eliminate voltage violations on transmission lines

g. Provide reactive power support for transmission/distribution bus

h. Provide spinning reserve support

i. Minimize cost of energy

j. Provide compatible combinations of above objectives

If, during optimization or execution of the solution, the circuit status changes, the application is interrupted and solution is re-optimized. If, during execution, some operations are unsuccessful, solution is re-optimized without involving the malfunctioning devices. If some of the controllable devices are unavailable for remote control, solution does not involve these devices but takes into account their reaction to changes in operating conditions.

Steps

VVC Function During Scheduled Run

#	Event	Name of Process/Activity	Description of Process/Activity	Information Producer	Information Receiver	Name of Info Exchanged	IntelliGrid Architecture Environments
3.1.1	Time for ADA VVC Controller scheduled run	Checking real-time data	DOMA function receives the scan of DMS SCADA data to be checked for changes in topology. It also receives the latest relevant analog data.	DMS SCADA database	DOMA function	DMS real-time analog, status & TLQ data, status of voltage controllers, DER modes of operation, and settings	Intra-Control Center Environment
3.1.2		Checking real-time data	DOMA function receives the scan of Energy Management System SCADA data to be checked for relevant changes or events.	Energy Management System SCADA database	DOMA function	Energy Management System real-time analog, status, TLQ data	Intra-Control Center Environment
3.1.3		VVC performs optimization according to current objective	The fact that no events and changes in connectivity are detected is communicated to ADA VVC Controller. ADA VVC Controller is triggered by the time schedule.	DOMA function	ADA VVC Controller	No events or changes in connectivity detected, command to start scheduled run	Intra-Control Center Environment
3.1.4		VVC performs optimization according to current objective	VVC receives the excerpts from ADA database.	ADADatabase	ADA VVC Controller	Excerpts from ADA database	Intra-Control Center Environment
3.1.5		VVC performs optimization according to current objective	Relevant results of VVC optimization are displayed for the System Operator.	ADA VVC Controller	System Operator	VVC status, present and recommended bus kV, benefits, expected lowest and highest load voltage	User Interface
3.1.6		VVC performs optimization according to current objective	Relevant results of VVC optimization are sent to controllers in the field.	ADA VVC Controller	DMS SCADA database	Recommended settings to relevant voltage and power electronic controllers, DER modes of operation and settings, capacitor status	Intra-Control Center Environment
3.1.7		VVC performs optimization according to current objective	Relevant results of VVC optimization are stored in ADA historic database.	ADA VVC Controller	ADA Historic Database	VVC and LTC states and settings; VVC limits and benefits; losses, voltage, objective function and total demand before and after optimization, logs	Intra-Control Center Environment
3.1.8		Checking real-time data	DOMA function receives the scan of DMS SCADA data to be checked for changes in topology and confirmation of execution of VVC commands. It also provides the latest relevant analog data.	DMS SCADA database	DOMA function	DMS real-time analog, status & TLQ data, status of voltage controllers, confirmation of execution of VVC commands	Intra-Control Center Environment
3.1.9		Information for System Operator	System Operator’s display is regularly updated with data associated with LTC and VVC performance.	DMS SCADA database	ADA VVC Controller	VVC: status, integrity, settings, limits, bandcenter, objective; LTC: status, position; bus voltage limits	Intra-Control Center Environment

VVC Function During Event Run

#	Event	Name of Process/Activity	Description of Process/Activity	Information Producer	Information Receiver	Name of Info Exchanged	IntelliGrid Architecture Environments
3.2.1-1	ADA VVC Controller during event run	DOMA detects load voltage or overload violation	DOMA function detects load voltage or overload violation and initiates ADA VVC Controller.	DOMA function	ADA VVC Controller	Command to initiate VVC	Intra-Control Center Environment
3.2.1-11, 3.2.1-111, 3.2.1-1111		Checking real-time data	DOMA function checks the real-time data for changes, alarms.	DMS SCADA database	DOMA function	DMS real-time analog, status, TLQ data, confirmation of execution of VVC commands, status of voltage controllers	Intra-Control Center Environment
3.2.1-12, 3.2.1-112, 3.2.1-1112		Checking real-time data	DOMA function checks the real-time data for changes, alarms.	SCADA Energy Management System database	DOMA function	Energy Management System real-time analog, status, TLQ data	Intra-Control Center Environment
3.2.1.13		Changing current objective to load reduction within normal limits due to high energy price	DOMA function detects high-energy price and issues command to change VVC objective.	DOMA function	ADA VVC Controller	Command to change optimization objective	Intra-Control Center Environment
3.2.1.14		VVC performs optimization according to current objective	DOMA function issues command to initiate VVC.	DOMA function	ADA VVC Controller	Command to initiate VVC	Intra-Control Center Environment
3.2.2		VVC performs optimization according to current objective	ADA VVC Controller receives excerpt from ADA database updated with latest SCADA scan.	ADADatabase	ADA VVC Controller	ADA database excerpt	Intra-Control Center Environment
3.2.3		VVC performs optimization according to current objective	VVC issues information relevant for System Operator.	ADA VVC Controller	System Operator	VVC status, present and recommended bus kV, benefits, expected lowest and highest load voltages	User Interface
3.2.4		VVC performs optimization according to current objective	DMS SCADA database receives results of optimization.	ADA VVC Controller	DMS SCADA database	Recommended settings to relevant voltage and power electronic controllers, DER modes of operation and settings, capacitor status	Intra-Control Center Environment
3.2.5		VVC performs optimization according to current objective	Selected results are archived in ADA Historic Database.	ADA VVC Controller	ADA Historic Database	VVC and LTC states and settings; VVC limits and benefits; losses, voltage, objective function and total demand before and after optimization, logs	Intra-Control Center Environment
3.2.6		VVC performs optimization according to current objective	ADA VVC Controller initiates DOMA function after confirmation of execution is received.	ADA VVC Controller	DOMA function	Command to initiate DOMA	Intra-Control Center Environment
3.2.7		DOMA function performs analysis	DOMA function, after detecting a violation present during the after-optimization conditions, sends alarm to System Operator.	DOMA function	System Operator	Alarm for System Operator	User Interface
3.2.8		Prearming RAS function adjusts settings of relevant groups of load shedding	DOMA function, after detecting that optimization has not eliminated transmission violation, sends an alarm to the System Operator and triggers pre-arming of RAS.	DOMA function	Remedial Action Scheme, System Operator	Information for prearming Remedial Action Scheme	User Interface
3.2.9		Data for System Operator	Relevant for System Operator VVC and LTC settings, limits and statuses are displayed.	DMS SCADA database	System Operator	VVC: status, integrity, settings, limits, bandcenter, objective LTC: status, position	User Interface
3.3.1		VVC determines violation can not be eliminated through optimization	DOMA function detects load voltage or voltage violation.	DOMA function	ADA VVC Controller	Command to initiate VVC	Intra-Control Center Environment
3.3.2		VVC determines violation can not be eliminated through optimization	VVC receives excerpts from ADA database updated with latest SCADA scan.	ADA Database	ADA VVC Controller	Excerpts from ADA database	Intra-Control Center Environment
3.3.3		VVC determines violation can not be eliminated through optimization	VVC initiates MFR to eliminate the violation.	ADA VVC Controller	MFR function	Command to initiate MFR	Intra-Control Center Environment
3.3.4		VVC determines violation can not be eliminated through optimization	ADA historic database receives logs issued by VVC.	ADA VVC Controller	ADA Historic Database	Logs	Intra-Control Center Environment
3.4.1		DOMA function detects distribution model inconsistency	After detecting distribution model inconsistency, DOMA function sets an inconsistency flag to put VVC in a default mode.	DOMA function	ADA VVC Controller	Distribution model inconsistency flag	Intra-Control Center Environment
3.4.2		VVC switches to default settings for portions of distribution system with inconsistent model	The fact that the VVC is switched to default setting has been issued is received by DMS SCADA database.	ADA VVC Controller	DMS SCADA database	Fact that VVC is switched to default setting	Intra-Control Center Environment
3.4.3		VVC switches to default settings for portions of distribution system with inconsistent model	Log is stored in ADA historic database.	ADA VVC Controller	ADA Historic Database	Log	Intra-Control Center Environment
3.5.1		Checking real-time data	DOMA function checks the real-time data for changes, alarms.	DMS SCADA database	DOMA function	DMS real-time analog, status, TLQ data, confirmation of execution of VVC commands, status of voltage controllers	Intra-Control Center Environment
3.5.2		Checking real-time data	DOMA function checks the real-time data for changes, alarms.	SCADA Energy Management System database	DOMA function	Energy Management System real-time analog, status, TLQ data	Intra-Control Center Environment
3.5.3		VVC determines there is room for optimization and performs optimization within emergency limits	DOMA detects transmission emergency limit violation and issues a command to initiate VVC.	DOMA function	ADA VVC Controller	Command to initiate VVC	Intra-Control Center Environment
3.5.4		VVC determines there is room for optimization and performs optimization within emergency limits	VVC receives excerpts from ADA database updated with latest SCADA scan.	ADA Database	ADA VVC Controller	Excerpts from ADA database	Intra-Control Center Environment
3.5.5		VVC determines there is room for optimization and performs optimization within emergency limits	Selected optimization results are displayed for the System Operator.	ADA VVC Controller	System Operator	VVC status, present and recommended bus kV, expected lowest and highest load V, flag of using emergency limits	User Interface
3.5.6		VVC determines there is room for optimization and performs optimization within emergency limits	DMS SCADA database receives relevant optimization results.	ADA VVC Controller	DMS SCADA database	Recommended settings to relevant voltage and power electronic controllers, DER modes of operation and settings, capacitors status	Intra-Control Center Environment
3.5.7		VVC determines there is room for optimization and performs optimization within emergency limits	Selected results are archived in ADA historic database.	ADA VVC Controller	ADA Historic Database	VVC and LTC states and settings; VVC limits and benefits; losses, voltage, objective function and total demand before and after optimization, logs	Intra-Control Center Environment
3.5.8		VVC determines there is room for optimization and performs optimization within emergency limits	ADA VVC Controller initiates DOMA function after confirmation of execution is received.	ADA VVC Controller	DOMA function	Command to initiate DOMA	Intra-Control Center Environment
3.5.9		DOMA function performs analysis	DOMA function, after detecting a violation present during the after-optimization conditions, sends alarm to System Operator.	DOMA function	System Operator	Alarm for System Operator	User Interface
3.5.10		Prearming RAS adjusts settings of relevant groups of load shedding	DOMA function, after detecting that optimization has not eliminated transmission violation, sends an alarm to pre-arming RAS function.	DOMA function	Prearming of RAS schemes function	Alarm for prearming RAS function	Intra-Control Center Environment
3.5.11		Data for System Operator	Relevant for System Operator VVC and LTC settings, limits, and statuses are displayed.	DMS SCADA database	System Operator	VVC: status, integrity, settings, limits, bandcenter, objective LTC: status, position	User Interface

VVC Function Participation in Severe Emergency in Bulk Power System with Intentional Islands