MESSIB-Electrical Energy Storage Using Flywheels-website

7/28/2019 MESSIB-Electrical Energy Storage Using Flywheels-website

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Electrical energy storage using flywheels

A new lightweight and high strength orthotropic composite wheel for FW system in buildings with

improved kinetically storage capabilities and electrical performance

The objective was to design and build a kinetic energy storage device for use in office buildings,

homes, residences and other buildings, where could be used, with the aim of better management of

energy produced and consumed.

Flywheels are well suited for short time storage (seconds to minutes) and high number of load-

unload cycles. In this regard there are several clear objectives to achieve:

Bioclimatic buildings that have their own renewable power generation systems,

available storage capacity of the energy generated when it is not consumed in order

to take advantage, and also to provide the energy needed when there is not

sufficient power generated.

Figure 1: Energy storage and management

The implementation of this technology for renewable energy allows energy management more

efficient and consume fewer resources. Currently, large amounts of resources are wasting by not

being able to store unused energy at production time.

The current barrier when applied to buildings is to achieve an enough amount of energy and safety

risk.


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The composite rotor allows higher speed and enable the storage of greater amounts of energy

(50.000rpm 2,5MJ 100Kw), in comparison with other materials. An important consideration is

that fibre reinforced composite rotors fail in a less destructive manner than metallic rotors, and is

thus intrinsically safer.

Employing active magnetic bearings allows the reduction of losses and noise and a more efficient

control at high speeds. In the same objective, integrates the vacuum generating system.

The mechanical design has been revised and focused on obtaining an efficient machine but from the

perspective of an economic and safety product.

The bidirectional AC/DC converter and the STS (static transfer switch), are integrated to process and

control the energy flows so as to optimize the energy consumption.

Activities within the MESSIB project:

Development of a composite flywheel.

Development of flywheel with magnetic bearings and high vacuum.

Development of a power conversion architecture

Integration, additional elements and laboratory test

Manufacturing techniques for adaptable solutions for buildings and districts

Achievements and progress during the MESSIB project:

Definition of specifications and calculations for flywheel solution

Design and manufacturing development for the flywheel and converter solution

Setup and fine tune for standard and limit work conditions:

Adjustment of levitation system (current loops, position, thermal, ...)

Rotodynamic conditions adjustment

System tested in industrial environment.

High power and short time cycles flattened

The most important milestones of the design and manufacture of flywheel:

The various figures below show the most important milestones of the design and manufacture offlywheel. The designs and manufacturing processes have been carefully analyzed and defined in

order to achieve a prototype machine with industrial specifications and tuning has been done

considering working conditions for maximum performance and safety critical conditions.


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Wheel

Fiber IM7 and resin 8552

Interior diameter 204mm,

exterior diameter 314mm,

fiber volume 55%, and fiber

angle 80.

Figure 2: Wheel grinding and polished process

Figure 3: Campbell diagram natural frequency

versus Rotationial frequency

Mechanical design and manufacture

Resistant structural

calculation

Rotodynamic calculations

Union fiber wheel and

preloaded titanium hub

Figure 4: Shaft and wheel tight-fitting process

0 1 2 3 4 5 6 7 8 9 10

x 104

0

200

400

600

800

1000

1200

1400

1600

1800

Spinning Speed [RPM]

NarutalFrequency[Hz]

External Diameter 314[mm]/Length 225[mm]

External Diameter 264.6[mm]/Length 310[mm]

Spinning Speed


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Figure 5: Top magnetic bearing configuration

Levitation & control

Upper and lower radial

bearings

1 axial bearing

High resolution position

sensors

Dedicated electronic control

(DSP+FPGA+NETBURNER)

Figure 6: Radial bearingmagnetic simulation

Figure 7: Real time control board


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Converter

Commutation module

(MCm);

Frequency variation device

(MCD)

Smart bidirectional converter

AC/DC (F&B Gen)

Figure 8: Bidirectional converter

Main Result: COMPLETE FLYWHEEL SYSTEM

TheMESSIB flywheel storage system is a fully integrated line interactive system that uses a flywheel

to store mechanical energy in a rotating mass. When utility power is interrupted, the ESF (Energy

Storage Flywheel) will convert the mechanical energy stored in the flywheel into electrical energy.

Kinetic energy storage energy suits well for applications with high power, low energy and high

number of load-unload cycles. Said energy is supplied to the external load until one of the following

conditions

occurs:

The standby generator assumes the load

The utility power is available again

The flywheel runs out of energy

The ESF can be used in a wide range of commercial power applications and provides voltage

regulation, protection and well regulated power to cover critical loads, sags, surges or outages.

Figure x: Line regulation


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Configuration

The mechanical design has been optimized towards a safe product, yet efficient and cost-effective. The following picture shows the current machine configuration.

Figure 9: Flywheel configuration Figure 10: Flywheel connection

System features

High reliability

Harmonic cancellation

Transient protection

High-speed voltage protection

Power factor improvement

Remote control & monitoring

Low maintenance

Specifications Energy: 2.5 MJ Power: 100kW Rotational speed: 50,000 rpm Voltage interface: 240 a.c . 3 ph, 400V dc Working temp: -20C - 50C Storage temp: -20C - 80C Rotor: CFRP with titanium hub Active magnetic bearings. Axial bearing only

counteracts gravity 10-2 mbar


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Technology

The solution integrates various technologies developed byTekniker

Active magnetic bearings Real time control electronics Power amplifiers High-reliability position sensors CFRP Rotors and wheels

Energy management

The system presents several operation modes which allow that the ESF automatically functions to

supply AC electrical power to the critical load. The ESF continually monitors itself and the incoming

utility power, and automatically switches between these modes as-requested, with no interventionfrom an operator. The detection and switching logic inside the ESF ensures that changes in the

operation mode are automatic and transparent to the critical load. The figures that follow hereunder

identify the main components in the systems and the location of the Input, Output and Converter

nodes.

Figure 11: Block diagram of a working configuration

Paralleling power stages

In order to handle high power capabilities and because the cost of developing large items raises

production costs appreciably, is more efficient and easier to control the use of flywheel battery

configurations.

The figure shows a typical configuration of a flywheels battery used in powerline quality

improvement.
http://www.tekniker.es/http://www.tekniker.es/http://www.tekniker.es/http://www.tekniker.es/


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Figure 12: Flywheel battery configuration

Renewable energy management

The implementation of this technology for renewable energy storage permits a more efficient energy

management and ensures the consumption of fewer resources. At present, large amounts of

resources are being wasted due to the inability of existing systems to store unused energy during

production.

(see Figure 1)


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Figure 13: Wheel surface grinding

Figure 14: Electrical connection

Figure 15: Vacuum power connectors


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Figure 16: Wheel surface coating

Figure 17: Insertion of the wheel intohousing


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Figure 18: Flywheel connection

Figure 19: Axial bearing development

Figure 18: Tekniker bunker facilities:

general view


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Top loading area


Closing system of the upper cover


Closing system of the upper cover


Access area


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Internal view

Figure 24: Wheel grinding

Figure 25: Shaft and hub tight-fitting

process

Figure 26: Initial setup


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Figure 27: Winding process

Figure 28: Winding process

Documents

MESSIB-Electrical Energy Storage Using Flywheels-website