Chapter 6 energy storage+ electric vehicles feb 2011 compatibility mode

•High speed reactive power control is possible through the use of flexible ac transmission systems FACTS devices.. Energy Storage Systems for Advanced Transmission and Distribution Appl

Green Energy Renewable Energy Systems

Course-Biên sọan: Nguyễn Hữu Phúc Khoa Điện- Điện Tử- Đại Học Bách Khoa TPHCM

Energy Storage Systems For Advanced Power Applications

Paulo F Ribeiro, Ph.D., MBA PRIBEIRO@CALVIN.EDU

Calvin College

Grand Rapids, Michigan, USA

•Present socio-economic realities – limits developments

•Better Understanding of Performance Issues is Needed

Advanced / Super Capacitors

Superconducting Energy Storage Systems

•Electric Power Systems - Experiencing Dramatic Changes

•Electric load growth and higher regional power transfers in a largely interconnected network: >>complex and less secure power system operation

•Power generation and transmission facilities - unable to meet these new demands

•Growth of electronic loads has made the quality of power supply a critical issue

•Power system engineers facing these challenges - operate the system in more a

flexible.

•

•In face of disturbances - generators unable to keep the system stable

•High speed reactive power control is possible through the use of flexible ac

transmission systems (FACTS) devices

•Better solution: rapidly vary real power without impacting the system through power circulation

•

•Recent developments and advances in energy storage and power electronics

technologies

Energy Storage Systems for Advanced Transmission and Distribution Applications

•Energy Storage Technology – Power Convert

•Factors:

The amount of energy that can be stored in the device.

The rate at which energy can be transferred into or out of the storage device.

•Power/Energy ranges for near to mid-term technology have projected

•Integration of energy storage technologies with Flexible AC Transmission Systems (FACTS) and custom power devices are among the possible advanced power applications utilizing energy storage.

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1

10

100

P u m p e d S to r a g e H ig h C a p a c ity , L o w C os t S p e c ial S ite R e q u ire m e n t

C o m p re s s e d A ir H ig h C a p a c ity , L o w C os t S p e c ial S ite R e q u ire m e n t,

L i-io n B a tte rie s H ig h P o w e r & E n e rg y

A Superconducting Magnetic Energy Storage (SMES)

Controller

Coil Protection

Cryogenic System

VCoil

ICoil

Dewar Power Conversion System

CSI or VSI + dc-dc chopper

Transformer Bypass

Switch Coil AC

Line

A Superconducting Magnetic Energy Storage (SMES)

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Solenoid Configuration

(100 MJ – 4kA - 96MW System)

A Superconducting Magnetic Energy Storage (SMES)

SMES’ efficiency and fast response capability (MW/millisecond) have

been, and can be further exploited in applications at all levels of

electric power systems Potential applications have been studied since 1970’s

a) load leveling,

b) frequency support (spinning reserve) during loss of generation,

c) enhancing transient and dynamic stability,

d) dynamic voltage support (VAR compensation),

e) improving power quality,

f) increasing transmission line capacity, thus enhancing overall security

and reliability of power systems

Further development continues in power conversion systems and control

schemes, evaluation of design and cost factors, and analyses for

various SMES system applications

A Superconducting Magnetic Energy Storage (SMES)

Energy-power characteristics for potential SMES applications for generation, transmission, and distribution

10 100 1,000

B Battery Energy Storage Systems (BESS)

Batteries are one of the most cost-effective energy storage

technologies available, with energy stored electrochemically.

Key factors in battery for storage applications include: high

energy density, high energy capability, round trip efficiency,

cycling capability, life span, and initial cost.

Battery technologies under consideration for large-scale

energy storage.

Lead-acid batteries can be designed for bulk energy storage

or for rapid charge/discharge.

Mobile applications are favoring sealed lead-acid battery

technologies for safety and ease of maintenance.

Valve regulated lead-acid (VRLA) batteries have better cost

and performance characteristics for stationary applications.

Photo Source: UP Networks

BESS Example – Transmission/Distribution Application

Lead-acid batteries, have been used in a few commercial and large-scale energy management

applications

The largest one is a

40 MWh system in Chino, California, built in 1988 The table below lists and compares the lead-acid storage

systems that are larger than 1MWh

C Advanced / Super / Capacitors

R

i C

dt i

dV = * + *

•The amount of energy a capacitor is capable of storing can be increased by either increasing the capacitance or the voltage stored on the capacitor

•The stored voltage is limited by the voltage withstand strength of the dielectric

•As with batteries, the turn around efficiency when

charging/discharging capacitors is also an important

consideration, as is response time

•The effective series resistance of the capacitor has a significant impact on both The total voltage change

when charging or discharging capacitors is shown in equation

NESSCAP 10F/2.3V

C Advanced / Super / Capacitors

Advantages Disadvantage

Energy Efficiency (higher) Maintenance

Discharge

D Flywheel Energy Storage (FES)

Flywheels can be used to store energy for power systems

when the flywheel is coupled to an electric machine

Stored energy depends on the moment of inertia of the rotor

and the square of the rotational velocity of the flywheel

Energy is transferred to the flywheel when the machine

operates as a motor (the flywheel accelerates), charging the

energy storage device The flywheel is discharged when the

electric machine regenerates through the drive (slowing the

flywheel).

The energy storage capability of flywheels can be

improved either by increasing the moment of inertia of

the flywheel or by turning it at higher rotational

velocities, or both

Active Power, Inc.

The moment

of inertia (I) depends on the radius, mass, and height (length) of the rotor

D Flywheel Energy Storage (FES)

Flywheel energy storage coupled

to a dynamic voltage restorer.

Manufacturer Technology Capacity (kW) Capacity (time)

A Flywheel 120 kW 20 sec

B Flywheel/Battery 160 kW 15-30 min

C Battery 3.1 - 7.5 kVA 15 min

Battery 0.7 - 2.1 kVA 10 min Battery 700 - 2100 kVA 13 min Battery 7.5 - 25 kVA 17 min

D Battery 1250 kVA 15 min

Flywheel 700 kW 10 min

E Battery 450 - 1600 kVA 6-12 min

F Flywheel/Battery 5-1000 kVA 5-60 min

G Battery 0.14 - 1.2 kVA 5-59 min

H Battery 0.28 - 0.675 kVA 15 min

Source: EPRI

Example – End-User Application

Energy Storage / UPS Systems

Advanced Power Systems Applications

SMES can inject and absorb power rapidly, but battery and flywheel systems are modular and more cost effective Advanced flywheels and advanced capacitor technologies are still being developed and are emerging as promising storage technologies as well.

Performance \ ESS SMES BESS FES Advanced

capacitor Dynamic Stability

Needs to be explored Transient Stability

A Integration of Energy Storage Systems into FACTS Devices

FACTS controllers are power electronics based devices that can rapidly influence the transmission system parameters such as impedance, voltage, and phase to provide fast control of transmission or distribution system behavior

FACTS controllers that can benefit the most from energy storage are those that utilize a voltage source converter interface to the power system with a capacitor on a dc bus This class of FACTS controllers can be connected to the transmission system in parallel

(STATCOM), series (SSSC) or combined (UPFC) form, and they can utilize or redirect the available power and energy from the ac system

Without energy storage, FACTS devices are limited in the degree of freedom and

sustained action

Device MVA

FACTs Device Reactive Power (Q)

Real Power from SMES Converter Losses

A Integration of Energy Storage Systems into FACTS Devices

Advanced Solutions

Transmission Link

Enhanced Power Transfer and Stability

Line Reconfiguration

Fixed Compensation

FACTS Energy Storage

Better Protection Increased Inertia

Breaking Resistors Load Shedding

FACTS Devices

Traditional Solutions

SVC STATCOM TCSC, SSSC UPFC

Transient Stability Damping Power Swings Post-Contingency Voltage Control Voltage Stability Subsynchronous Res.

Generation Transmission Distribution End-User

Energy Storage for

Continuity Reliability Power Quality

STATCOM with SMES

The performance of a powerelectronics energy-storage-enhanced device is very sensitive to the location with regard to generation and loads, topology of the supply system, and configuration and combination of the compensation device.

-STATCOM with SMES

STATCOM/SMES dynamic

response to ac system

oscillations

2 STATCOMs 1 STATCOM + SMES

Voltage and Stability Control Enhanced Voltage and Stability Control

STATCOM with SMES

Location and Configuration Type Sensitivity

FACTS with BESS

+_

External Power Bus 2

External Power Bus 1

Reference Values

Six Control Signals

Six Control Signals

Measured Values

(a) active power from 50W to 400 W (b) reactive power from 755Var to 355Var

Predicted and experimental response of the SSSC/BESS

FACTS with BESS

(a) STATCOM vs STATCOM/BESS

(b) SSSC vs SSSC/BESS (c) STATCOM/BESS vs

SSSC/BESS vs UPFC

Active power flow between areas

FACTS with BESS

Voltage at Area 2 bus

(a) STATCOM vs STATCOM/BESS

(b) SSSC vs SSSC/BESS

B Advanced HVDC Transmission and

Distribution

Improvements in power electronic device

technologies have led to significant

improvements in the flexibility of dc

transmission systems through the ability to use

voltage source converters.

Traditional direct current systems see limited

use as high power, high voltage dc (HVdc)

transmission systems.

Advanced dc systems allows lower voltage dc

transmission system capable of supporting a

large number of standard “off the shelf”

inverters

Energy storage can be added to the dc system,

providing improved response to fast load

changes drawn by the inverters

Bus

LOAD AC

LOADAC

LOAD AC

LOAD AC

C Power Quality Enhancement with Energy Storage

Custom power devices address problems found at distribution level, such as voltage sags, voltage swells, voltage transients and

momentary interruptions

The most common approaches to mitigate these problems focus on customer side solutions such as Uninterruptible Power Supply (UPS) systems based on battery energy storage

Alternative UPS systems based on SMES and FESS are also available.

STATCOM Reactive Power Only Operates in the

vertical axis only

STATCOM + SMES Real and Reactive Power Operates anywhere within the

PQ Plane / Circle (4-Quadrant)

PQ

The Combination or Real

and Reactive Power will

typically reduce the Rating of

the Power Electronics front

end interface.

Real Power takes care of

power oscillation, whereas

reactive power controls

voltage.

The Role of Energy Storage: real

power compensation can

increase operating control and

reduce capital costs

P - Active Power

Q - Reactive Power MVA Reduction

FACTS + Energy Storage

Switching Technology

Transition Approach

Circuit Topology

Device Type

Power Electronics - Semiconductor Devices

Decision-Making Matrix

E1 / 1

E2 / 2I

P&Q

Plus Energy Storage

Regulating Bus Voltage + Injected Voltage + Energy Storage

Can Control Power Flow Continuously, and Support Operation Under Severe Fault Conditions

(enhanced performance)

Universal Topology + Energy Storage Implementation

Cost Considerations

Energy storage system costs for a transmission application are driven by the operational requirements

The costs of the system can be broken into three main components:

The energy storage system,

The supporting systems (refrigeration for SMES is a big item) and

The Power Conversion System

The cost of the energy storage system is primarily determined by the amount of

energy to be stored The configuration and the size of the power conversion system may become a dominant component for the high-power low-energy storage

applications For the utility applications under consideration, estimates are in the range of $10-100K per MJ for the storage system

Cost Considerations

In order to establish a realistic cost estimate, the following steps are

suggested:

· identify the system issue(s) to be addressed;

· select preliminary system characteristics:

· define basic energy storage, power, voltage and current requirements;

· model system performance in response to system demands to establish effectiveness of the device;

· optimize system specification and determine system cost;

· determine utility financial benefits from operation;

· compare system’s cost and utility financial benefits to determine

adequacy of utility’s return on investment,

· compare different energy storage systems performance and costs

Technology & Cost Trends

•enhanced power quality

•transmission capacity enhancement

•area protection, etc

FACTS (Flexible AC Transmission Systems) devices which handle both real and reactive power to achieve improved transmission system

performance are multi-MW proven electronic devices now being

introduced in the utility industry In this environment, energy storage is a logical addition to the expanding family of FACTS devices.

•As deregulation takes place, generation and transmission resources will be utilized at higher efficiency rates leading to tighter and moment- by-moment control of the spare capacities

•Energy storage devices can facilitate this process, allowing the utility maximum utilization of utility resources

•The new power electronics controller devices will enable increased

utilization of transmission and distribution systems with increased

Storage batteries for solar and wind systems Application of the wind turbine system

• Brief state of art of storage solutions

• Battery technologies: Lead Acid, NiMH and Lithium ion

• Energetic models via Bond-Graph of electrochemical components

– Quasi-static energetic model of fuel cell

– Simple battery models: Lithium-ion and lead acid batteries

• Stationary batteries for wind and solar applications: technology & simple models

• Simple application examples:

– A remote site

– Solar pumping

• Application of the studied wind turbine system: Hybridization of the DC bus with an accumulator

2/19/2012 44

Energy Storage+Smart Grid

Energy Storage

Solutions

…and…

transport

Hybrid and Electric Vehicle Designs and

Their Impact on Energy

P T Krein

Director, Grainger Center for Electric Machinery

and Electromechanics Department of Electrical and Computer

Engineering

University of Illinois at Urbana-Champaign, USA

• Early electric cars and advantages

• Energy and power issues

• The modern hybrid

• Energy and environment motives for hybrids and electrics

• Near-term; myths and trends