flywheel energy storage by bhupendra kumar , srmgpc

8/2/2019 flywheel energy storage by bhupendra kumar , srmgpc

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OUTLINE

What is energy storage technology

Introduction

Operation of FES

Calculation of stored energy Benefits

Applications

Advantage & disadvantage


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WHAT IS ENERGY STORAGETECHNOLGY ?

Energy Storage technologies produce nonet energy, but can provide electric power

over limited periods of time.

Applications : Its presence in a system caneliminate the voltage swings caused byrapid changes in load, spare systemhardware from large transient currents,decrease demand charges, damp

oscillations.


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THREE COMPONENTAFFECTING COST

The cost of any electrical energy storagesystem has three components, one due tothe amount of energy stored, one due to thepower at which it must be discharged, andone from the balance of systems. These are

nearly independent.


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Contd

In the case of flywheels, the first is theflywheel rotor, the second includes themotor generator elements and the powerelectronics, and the third includes thecabinet, cooling system and other ancillarysystems.

Energy wheels are optimized for long

discharge time, and power wheels areoptimized for short discharge time.


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INTRODUCTION

Flywheel energy storage systems storekinetic energy by constantly spinning a

compact rotor in a low-friction environment.. When short-term back-up power isrequired, the rotor's inertia allows it tocontinue spinning and the resulting kinetic

energy is converted to electricity.


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BLOCK DIAGRAM OF FESSYSTEM


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OPERATION

"no-break" system, metal flywheelconnected to motor & generator.

Input is available : machine operates in

motor mode as a synchronous conditioner. Input unavailable : synchronous machine

operates as generator using flywheelskinetic energy to supply output voltage.

Regulation system maintains output voltagein spite of drop in flywheel speed.


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FES IN DISTRIBUTEDGENERATION SYSTEM

FOUR BENEFITS:

Stabilize voltage for power users Improve generator fuel efficiency

Reduce generator emissions

Increase generator service life


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STEP INCREASE/DECREASE OFLOAD AT DISTRIBUTED GENERATIONSYSTEM


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CALCULATION OF STOREDENERGY Stored energy = sum of kinetic energy of

individual mass elements that comprise theflywheel

Kinetic Energy = 1/2*I*w2

where I = moment of inertia

w = rotational velocity

I = k*M*R2

Inertial constants for different shapes:Wheel loaded at rim (bike tire); k = 1Solid disk of uniform thickness; k =

etc.


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BENEFIT OF FES SYSTEM OVEROTHER BATTERIES

The design life for a flywheel is typicallyabout 20 years, while most batteries in UPSapplications will only last 3 to 5 years.

Frequent cycling has little impact on

flywheel life. In contrast, frequent cyclingsignificantly reduces battery life.

Flywheels avoid battery safety issuesassociated with chemical release.

Flywheel reliability is 5 to 10 times greaterthan a single battery string or about equalto two battery strings operating in parallel.


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COST ANALYSIS


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APPLICATIONS

Peak power buffer

In distribution network

UPS system

Aerospace application

Electric cars

Rail electrification

Pulse power

Wind turbines


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ADVANTAGE

Reliability

Longer life

Reduction of Required Maintenance

Does Not Require a Temperature ControlledEnvironment

Lower Life-Cycle Costs

Lower mass/KW output 85-95% round trip efficiency

Greater peak load capability


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DISADVANTAGE

Low specific energy

Safety concerns

Less mature technology than chemicalbatteries

Tensile strength of a flywheel

High cost


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FES AS GREEN TECHNOLOGY

The primary method used today forfrequency regulation is to ramp fossilfuel power plants up and down,

producing significant emissions.Flywheels will provide more reliableregulation, while generating zero

direct emissions. This woulddramatically reduce CO2 emissions,as shown in the chart at right, basedon a study funded by the DOE.


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ENCLOSURE

The fast rotation of flywheel rotors issuitable for direct generation of high

voltage. This flywheel technology is scalable and

larger machines can be constructed for theapplications of e.g. stabilizing the electric

grid.

flywheel energy storage by bhupendra kumar , srmgpc

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