Archive for the ‘Quality Energy’ Category


Wind PV BESS hybrid power generation system with large-scale battery energy storage station

The Figure shown an example of Wind PV BESS hybrid power generation system with large-scale battery energy storage station (it is in BESS – Battery Energy Storage Station). It is used for compensation of aleatory energy production from wind turbine or PV plant. This BESS have orden of MW’s both for charge/discharge process.

Source:
Xiangjun Li, Dong Hui and Xiaokang Lai “Battery Energy Storage Station (BESS) – Based Smoothing Control of Photovoltaic (PV) and Wind Power Generation Fluctuations”. IEEE Transactions on Sustainable Energy, Vol. 4, No. 2, April 2013.

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The existing grid

As Figure demonstrates, the existing electricity grid is  a strictly hierarchical system in which power plants at the top of the chain ensure power delivery to customers’ loads  at the bottom of the chain. The system is essentially a oneway pipeline where the source has no real-time information about the service parameters of the termination points. The grid is therefore overengineered to withstand maximum anticipated peak demand across its aggregated load. And since this peak demand is an infrequent occurrence, the system is inherently inefficient. Moreover, an unprecedented rise in demand for electrical power, coupled with lagging investments in the electrical power infrastructure, has decreased system stability. With the safe margins exhausted, any unforeseen surge in demand or anomalies across the distribution network causing component failures can trigger catastrophic blackouts.

Source:
Hassan Farhangi “The Path of the Smart Grid” IEEE Power & Energy Mazagine. January/February 2010. Pag 18 -28.


Double three-phase VSI

The figure shows the scheme of a full power converter for a wind turbine. The machine-side three-phase converter works as a driver controlling the torque generator, using a vector control strategy. The grid-side three-phase converter permits windenergy transfer into the grid and enables to control the amount of the active and reactive powers delivered to the grid. It also keeps the total-harmonic-distortion (THD) coefficient as low as possible, improving the quality of the energy injected into the public grid. The induction generator of wind turbine is connected to a voltage-source inverter (VSI) used as a rectifier

Source:
Juan Manuel Carrasco, Leopoldo García Franquelo, Jan T. Bialasiewicz, Eduardo Galván, Ramón C. Portillo Guisado, Ángeles Martín Prats, José Ignacio León and Narciso Moreno-Alfonso “Power-Electronic Systems for the Grid integration of Renewable Energy Sources: A Survey”. IEEE Transactions on Industrial Electronics, Vol. 53, No. 4, August 2006


distribution demand between micosourses electrical network external and storage in a microgrid DC

Sun –> energy provided from photovoltaic energy plant.
Wind –> similar from wind turbine(s)
Batt –> similar from battery bank
ene –> similar injected from electrical network external or utility electric network

In other image in red is the total suministed for this sources and red line is the demand. Other images is cost, evoluction of energy supply from each source and more details. It is made for me (Jorge Mírez) in Matlabb/Simulink and I utilized concept of linear programming. Image is from my destokp laptop.


A block diagram of electrochemical energy storage

The energy storage systems operating in the microgrid are usually electrochemical ones, based on lead-acid battery. Typical estructure is shown in Figure. The microgrid and battery voltages are typically in range of 1000 V and rather similar.

Source:
Piotr Biczel. “Power Electronic Converters in DC Microgrid”. IEEE 5th International Conference – Workshop, Compatibility in Power Electronics, CPE 2007. Poland.


General block diagram of the DC microgrid power plant

El block diagram structure of a microgrid is shown in Figure. The main task of the power plant’s power electronic converter is to fit primary energy converter’s output voltage to the microgrid power line voltage, and source operating point control as well as low and high level microgrid’s control. The converter’s structure depends on a type of primary energy converter. A common feature of the converters concerns their output current. It should be permanent and low ripple.

Source:
Piotr Biczel. “Power Electronic Converters in DC Microgrid”. IEEE 5th International Conference – Workshop, Compatibility in Power Electronics, CPE 2007. Poland.


difference of time connected beetwen condensers of a bank condensers

This is my simulation made on Matlab/Simulink about difference time of conextion in bank condensers. The reactive power change in the time and it is aleatory. In this context, the mathematical models have that made the emulation of this performance.


simulation of deficit and surplus of two microgrids interconnected in Matlab

This is a part of my results about interconnected of two microgrids. It have flow power in function a its capacities, but probably a deficit and/or surplus in supply or demand in both microgrids is present. Negative is deficit in microgrid to import from other source different to other microgrid. Positivo is surplus in microgrid by export to other demand different at other microgrid. The figure is a simple example for to show that it is possible using mathematical modelling and simulations on Matlab of MathWork Inc.


when you exceed the nominal capacity of condensers bank

Sometimes, the reactive power in a electric system exceed the nominal capacity of condensers bank, therefore, all units capacitores is connected to give the maximum reactive power compensation possible. The figure is one of my simulations on Matlab and complement past post. Matlab is from MathWork Inc. The figure is the results of mathematical model of condensers bank operation (control and optimization).


cost_for_state_microgrid

A microgrid operate in state stable in this simulation made on Matlab. Each state represent a determinate time (10 minutes, 15 minutes o more o less). But during this time, la Microgrid makes calculations of energy cost dispatched for each source. The imagen is the global cost of microgrid (or similar or other electric system considering all costs).  The microgrid optimizer decides in base a linear programming the connection and disconnection of each source.


Schematic of a typical wind diesel hybrid system with storage

One of the most promising applications of renewable energy technology is the installation of hybrid
energy systems (HES) in remote areas, where the grid extension is costly and the cost of fuel increases drastically with the remoteness of the location. Recent research have shown that HES have an excellent potential, as a form of supplementary contribution to conventional power generation systems. In figure, one of the most common hybrid renewable system implemented and studied is described.

Source:
Francisco Goncalves Goina Mesquita. “Design Optimization of Stand-Alone Hybrid Energy Systems”. A Dissertation submitted under the scope of Mestrado Integrado em Engenharia Electrotécnica e de Computadores Major Energia. Fevereiro de 2010. Facultade de Engenharia da Universidade do Porto.

 


CBEMA curves specifying acceptable voltage sensitivity levels

Inthe recent past, dramatic improvements in productivity have been realized in the high technology sector as well as in the traditional industries. For the electric power supply to these industries, this hasled to a concomitant increase in the number of loads that are sensitive to power quality. Some of the industries that have such large sensitive loads include semiconductor manufacturing, textile mills, paper millsand plastic injection molding.Of course, a number of smaller but equally critical loads such as computers and electronic data processing equipment are also sensitive to power quality.Thetolerance
levels of computer equipment are specified by the Information Technology Industry/Computer and Business Equipment Manufacturers’ Association (ITI/CBEMA) curves. Figure illustrates theCBEMA curves. This figure gives thepercent of nominal voltage versus duration in (60-Hz) cycles. The CBEMA curves represent the boundary of the ac input voltage envelope that can be tolerated (typically) by most
computer-based equipment. The upper curve represents the maximum voltage below which the equipment will continue to function normally. The lower curve is the minimum voltage above which the equipment will continue to function normally.

As seen in Figure, the steady state range of tolerance for computer equipmentis ±10% from the nominal voltage, i.e., the equipment continues to operate normally when sourced by any voltages in this range for an indefinite period of time. Similarly, voltages wells to a magnitude of 120% of the nominal value can be tolerated for about 0.5 s or 30 cycles; voltage sags to 80% of nominal for 10 s, or 600 cycles, can be tolerated. When the supply voltage is outside the boundaries of the susceptibility curves, improvement of the quality of power supplied to sensitive loads is essential to avoid a possible failure in their operation.

Source:
G. Venkataramanan, M.S. Illindala, C. Houle, and R.H. Lasseter. “Hardware Development of a  Laboratory-Scale Microgrid Phase 1—Single Inverter in Island Mode Operation”. NREL. November 2002 • NREL/SR-560-32527


Optimum DG Penetration for Minimum Interruption Frequency

One question that most system operators are concerned with is the optimised DG penetration level. Relationship regarding different cost models between optimum DG penetration level and interruption frequency is indicated in Figure.

Optimum micro-source penetration level is positive related with the interruption frequency without DG penetration; especially for average interruption costs, the relationship is almost linear. This relationship is important for systemplanning; as the system interruption frequency without DG penetration is generally known, the system operator is able to roughly determine of the optimum DG penetration level from reliability point of view


System unavailability comparison of different countries EU

A reduction of system unavailability Q, as one example for system reliability indices, by the installation of micro-sources that enable (partial) island operation is demonstrated in Figure for selected European countries, compared to the case without DG.

The countries which have worse system reliability achieve higher improvements than the countries with high system reliabilities also in case without DG. For instance, in Portugal rural network the system unavailability decreases from more than 10 h/a to the value of below 1 h/a with maximum and average cost model; even with average cost model yearly unavailability is also reduced to approximate 4h/a. However, the improvement for German urban network and Holland network, which have already good system reliability without micro-sources, is not obvious, although system reliability is also improved to a certain extent in both networks. With higher interruption cost model, system reliability can be better improved. Higher interruption costs justify higher micro-source investment, thus achieving higher system reliability improvements.  Microgrid operation from reliability point of view is thus most beneficial in countries with lower power quality or in regions or for customer segments with comparably high outage costs.

Source:
Christine Schwaegerl. “DG3&DG4 Report on the technical, social, economic, and environmental benefits provided by Microgrids on power system operation”. Siemens AG. 2009


Roadmap for microgrid development

Currently, an increasing number of microgrid pilot sites can be observed in many parts of the world. It is true, however, that up to now,cost, policy and technology barriers have largely restrained the wide deployment of microgrids in distribution networks owing to their limited commercial appeal or social recognition. However, these three barriers are currently undergoing considerable changes – they are very likely to turn into key enablers in the future, eventually leading to a widespread microgrid adoption worldwide.

Firstly, the cost factor might prove to be the most effective driving force for microgrids in the very near future. This might happen not only because of the reduction of microsource costs, but also because of the relative changes of external opportunity costs due to economic (fluctuating market prices), technical (aging of network infrastructure) and environmental (emission trading) factors.

When microsource penetration at a LV grid becomes significant, participants in the electricity retail business will consider the aggregated power from small generators as a new market opportunity. Unlike in the case of VPP, microgrid stakeholders will eventually recognize a unique feature of aggregated microsource units, namely locality: the microsource units can potentially sell directly to end consumers in an “over-the-grid” manner. In order to turn this potential into reality, however, the second factor – appropriate policy and regulatory environment – is needed to enable the operation of a local market within a microgrid.

Finally, the adoption of favorable selling prices in local retail markets will attract even more microsource units, allowing the microgrid to operate islanded, if beneficial. With the help of smart metering, control and communication technologies, the microgrid operator will eventually be able to coordinate a large consortium of intermittent and controllable microsource units, as well as central and distributed storage devices, to achieve multiple objectives and, at the same time, to cater for the interests of different stakeholders.

Source:
MICROGRIDS: Architectures and Control
Nikos Hatziargynou


Possible communication infrastructure for the Smart Grid

The communication infrastructure of a power system typically consists of SCADA systems with dedicated communication channels to and from the System Control Centre and a Wide Area Network (WAN). Some long-established power utilities may have private telephone networks and other legacy communication systems. The SCADA systems connect all the major power system operational facilities, that is, the central generating stations, the transmission grid substations and the primary distribution substations to the System Control Centre. The WAN is used for corporate business and market operations. These form the core communication networks of the traditional power system. However, in the Smart Grid,it is expected that these two elements of communication infrastructure will merge into a Utility WAN.
An essential development of the Smart Grid (see figure ) is to extend communication throughout the distribution system and to establish two-way communications with customers through Neighbourhood Area Networks (NANs) covering the areas served by distribution substations. Customers’ premises will have Home Area Networks (HANs). The interface of the Home and Neighbourhood Area Networks will be through a smart meter or smart interfacing device.

Source:
SMART GRID
TECHNOLOGY AND APPLICATIONS
Janaka Ekanayake
Cardiff University, UK
Kithsiri Liyanage
University of Peradeniya, Sri Lanka
Jianzhong Wu
Cardiff University, UK
Akihiko Yokoyama
University of Tokyo, Japan
Nick Jenkins
Cardiff University, UK
A John Wiley & Sons, Ltd., Publication


Architecture of a DMSC

 

The figure shows the DMSC controller building blocks that assess operating conditions and find the control settings for devices connected to the network. The key functions of the DMSC are state estimation, bad data detection and the calculation of optimal control settings. The DMSC receives a limited number of real-time measurements at set intervals from the network nodes. The measurements are normally voltage, load injections and power flow measurements from the primary substation and other secondary substations. These measurements are used to calculate the network operating conditions. In addition to these real-time measurements, the DMSC uses load models to forecast load injections at each node on the network for a given period that coincides with the real-time measurements. The network topology and impedances are also supplied to the DMSC.
The state estimator uses this data to assess the network conditions in terms of node voltage magnitudes, line power flows and network injections. Bad measurements coming to the system will be filtered using bad data detection and identification methods.

Source:
SMART GRID
TECHNOLOGY AND APPLICATIONS
Janaka Ekanayake
Cardiff University, UK
Kithsiri Liyanage
University of Peradeniya, Sri Lanka
Jianzhong Wu
Cardiff University, UK
Akihiko Yokoyama
University of Tokyo, Japan
Nick Jenkins
Cardiff University, UK
A John Wiley & Sons, Ltd., Publication


charge and discharge battery

The present post describe the charge and discharge process of a battery bank of a microgrid. This microgrid have a aleatory voltage with inferior and superior limit. The current and electric power of charge and discharge is in picture. This simulation has writing and processing on Matlab/Simulink of MathaWorth Inc. Actually my interest is the control, optimization and management of microgrid DC. Greetings from Perú.


 

The information related to this post for sale for US $ 1000.00. You can make payments through PayPal account: jorgemirez2002@gmail.com or send an e-mail to receive PayPal invoice and make your payment quickly and easily. Tell us (through e-mail) the name of the input or inputs that interests you. // La información relacionada con este post en venta por US $ 1000.00. Usted puede hacer pagos a través de cuenta PayPal: jorgemirez2002@gmail.com o enviar un e-mail para recibir la factura de PayPal y hacer su pago de forma rápida y sencilla. Díganos (por medio de email) el nombre de la entrada o entradas que le interese.


a hybrid ac-dc microgrid system

La figura muestra el concepto de un sistema híbrido ac/dc donde varias fuentes y cargas ac y dc son conectadas a sus correspondientes redes ac y dc. Las redes ac y dc están conectadas a través de dos transformadores y conversores trifásicos ac/dc bidireccionales. Pueden observar la diversidad de micro fuentes que se está utilizando en la descripción de la microred, incluye los diferentes dispositivos de electrónica de potencia que sirven para adecuar la energía eléctrica desde fuentes y para cargas eléctricas. Hay vehículos eléctricos conectados a la microred. Los generadores eólicos tienen diferentes configuración de control (diferentes tipos de turbinas eólicas). Un grupo electrógeno diesel también se da, dado que estos grupos se consideran los que en último caso darán energía a la microred eléctrica en situaciones ya críticas pero a la vez rentables en lo posible en economía. Para todo esto se crea modelos matemáticos de cada elemento y luego se integran en un solo programa en que se puedan cambiar las condiciones de trabajo y analizar las variables de respuesta de lo que se desea estudiar. Yo lo hago en Matlab/Simulink para quienes deseen que les brinde el servicio de asesoramiento.


The information related to this post for sale for US $ 10.00. You can make payments through PayPal account: jorgemirez2002@gmail.com or send an e-mail to receive PayPal invoice and make your payment quickly and easily. Tell us (through e-mail) the name of the input or inputs that interests you. // La información relacionada con este post en venta por US $ 10.00. Usted puede hacer pagos a través de cuenta PayPal: jorgemirez2002@gmail.com o enviar un e-mail para recibir la factura de PayPal y hacer su pago de forma rápida y sencilla. Díganos (por medio de email) el nombre de la entrada o entradas que le interese.


Limits of Harmonic Distortion

La distorción armónica total de la corriente de salida en el rango de operación de un generador debe ser menor que 5 % de la corriente fundamental. La tabla muestra el valor de los armónicos que no deben exceder esos límites, expresados en relación a la corriente fundamental. Se habla de armónicos pares e impares, interesan todos dado que dependiendo del armónicos los efectos son diferentes, algunos de ellos se les puede reconocer con los cinco sentidos, otros requieren equipos como Analizadores de Redes Eléctricas. Que hacer en lugares con alta distorción armónica?. Una de las formas más fáciles es colocar un transformador de impedancia y un transformador de aislamiento (corregirme si me equivoco). Sin embargo, estas cosas para instalaciones medianas y grandes resultan bastante caras y espaciosas, considerando también las pérdidas asociadas a su funcionamiento. Por lo tanto, como cliente es pararse bien frente a las empresas de electricidad y como autoproductor de electricidad es comprar un buen generador que cumpla las exigencias de calidad de energía eléctrica, de esta manera proteges tu inversión y obtienes una fiabilidad alta y rentabilidad bastante ya que el beneficio es para toda la instalación (máquinas y sistemas de iluminación que en condiciones adecuadas brinda clima laboral adecuado sin flickers y/o baja iluminación).


The information related to this post for sale for US $ 1000.00. You can make payments through PayPal account: jorgemirez2002@gmail.com or send an e-mail to receive PayPal invoice and make your payment quickly and easily. Tell us (through e-mail) the name of the input or inputs that interests you. // La información relacionada con este post en venta por US $ 1000.00. Usted puede hacer pagos a través de cuenta PayPal: jorgemirez2002@gmail.com o enviar un e-mail para recibir la factura de PayPal y hacer su pago de forma rápida y sencilla. Díganos (por medio de email) el nombre de la entrada o entradas que le interese.