Pacific Gas & Electric Company

Smart Grid Application and Testing

Volt VAR Optimization Testing

Presenter : Neelofar Anjum Prepared By : Dr. Vaibhav Donde, John Mead and Neelofar Anjum

Outline

• Smart Grid Distribution Systems

• PG&E Smart Grid Strategy

• Volt/VAR Optimization as a critical

component of smart grid applications

• VVO integration and testing at PG&E ATS

laboratories

Smart Grid at Distribution Network Level

• Goal is to Improve overall efficiency, reliability, and cost-effectiveness of electrical system operations, planning, and maintenance

• Smart Distribution Grid • Controllable using switched

devices, regulators • Optimized for min demand &

losses • Enables demand participation • Variety of sensors, smart

meters, communications • Sustainable using Renewable

Generation

Cap, Reg, LTC PV, EV, DG

Sub automation

DMS

Recloser, sw

PG&E Smart Grid Strategy

Targeted deployment

• Extend pilots to targeted roll-outs based on benefits

• Insights used to feed the next cycle of technology deployment

Controlled Pilots • Implement tested technologies in a real-world but

controlled setting to demonstrate value

• Work with customers to prepare for the new technologies and services

Analysis • Standards

• Benchmark

• Industry scanning

• Project Goals & Definitions

Testing • Prototyping and testing of smart-grid

technologies before piloting

• Accelerate technology development and ensures standards compliance early on

• Develop preliminary customer communications to support pilots

PG&E Service Area in Northern & Central California

Implementation Approach

Volt VAR Optimization

VVO: Improving Energy Efficiency of Distribution Grids

System Losses (1-2%)

Customer Power Demand (voltage-dependent loads) (99-98%)

Mixed Integer Nonlinear Programming Problem

Problem Definition: Minimize (System losses + Customer Power Demand)

Subject to: • Power flow equations

(Unbalanced multi-phase system, mesh network possible)

• Voltage constraints (Phase to neutral, phase to phase)

• Current constraints (Cables, overhead lines, transformers, neutral, grounding)

• Operational constraints of actuators (Tap changers, shunt capacitors)

• DG considerations (various types, backfeed, max o/p)

Subject to: • Non-linear: voltage and current are coupled

• Mixed Integer: can’t have half a capacitor on

• Non-convex: can be a localized optimum point that is not true optimum

• Large scale due to multi-phase modeling

=

VVO Motivation • Reduction of demand typically ranges from 1% - 3.5%

– Cheap alternative to conventional generation – Reduction of total demand and need for peak-shaving generation – No carbon or emission offsets needed

• Reduction of energy consumption ranges from 1.3% - 2% • Reduce reactive power supplied via transmission system • Provide demand response capabilities • Decrease overloading of sub/feeder • Reduced complaints for high/low voltage • Improve customer voltage quality (less flicker) • Increase life of customer appliances by 15% • Lower customer bills by $16.50/year

– Recover like other conservation measures

Source: EPRI Seminar: Smart Control Centers and Feeders in a Smart Grid World (2011)

Voltage Profile along a Feeder

VVO helps optimize device setting & status for optimal voltage profile and demand reduction

Line Capacitor Line Regulator Substation LTC Load Distributed

Generation

• Voltage regulators and capacitors monitor data and coordinate actions to optimize the line

• Result is lower average voltage and a flatter voltage line

120V

126V

114V

Original voltage

Reduced voltage LTC Cap Reg

ANSI max

ANSI min

Typical VVO process Typical Field Devices

• LTCs • Primary devices

• Regulators • Cap Banks • Reclosers • EOL sensors

• Secondary devices

• Smart Meters

• FCIs

Monitor Field

Device Data

State Estimation

(if needed)

Optimization algorithms

(VVO)

Control Commands

(Via SCADA)

Validate Execution

ATS Smart Grid Test Capabilities

• PG&E ATS at San Ramon has advanced capabilities for smart grid technology testing

• High Voltage Test Dome can create up to 720,000 volts with full fog chamber capability

• High Current Test Yard can create up to 80,000 Amperes

• Distribution Test Yard (DTY) • Distribution Technology

Operations Center (DTOC) • Electric vehicles • Modular & renewable

generation

Distribution Test Yard Modular Generation

Customer Applications

Distribution Technology Operations Center

High Current Testing

EV Testing

High Voltage Testing

Radio Communication and SCADA Control

Hardwire and Simulation Controlled

Laboratory Testing of VVO at ATS

• Distribution Test Yard (DTY) is an integrated facility for evaluation, testing and demo of distribution system smart grid technologies

• Third-party VVO solutions are chosen for integration into DTY, lab testing and pilot

• Integration also involves interfacing with PG&E SCADA and smart-meters

• Hardware in loop testing will ensure safe operation

Three circuit breakers/feeders

DTY can be powered from either a 480 Volts or 21kV Source

Underground Distribution

Overhead Distribution

Regulator banks

Capacitor banks

VVO Testing Setup • Feeder model is

simulated in CYMDIST • Programmable Power

sources will be used to create the real field conditions into devices from Simulation results or historical data

• VVO receives information from SCADA and AMI and sends new controls to SCADA

DTY

Challenges

• Data Quality and Availability

• Integration with other Systems

• Closed loop Controls

• Computation Capabilities

• Communication

• Interoperability

• Security Guidelines

Q & A

Contact : Neelofar Anjum Supervisor, Smart Grid Testing and Application

neelofar.anjum@pge.com

Potential Used Cases