Archivo para febrero, 2016


Annual historic energy demand of Ecuador country by years from 1999 to 2012

This figure represents the electrical demand in Ecuador. It is noted that during the study period, nearly doubled the demand for electricity. Currently Ecuador already has a transmission line at 500 kV. With technology centers as Yachay, I recommend that Ecuador must bet for the development of technologies such as solar photovoltaics, wind turbines and biomass. Other technologies are possible and with higher added value.

 

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my simulation about condenser bank working

This is my simulation about the to work (on-off) of condenser bank. This bank is made by many condensers of different capacity. The model and simulation is implemented on Matlab of MathWork Inc. The little difference is result of maximun capacity and real reactive demand.


Allowable Ampacities of Insulated Conductors Rated 0-2000 Volts

This is a important data in my research and in any calculate by size conductors wire in distribution system and applicantions in house, industry and similars.

Source:
http://www.usawire-cable.com/pdfs/nec%20ampacities.pdf 


Simplified layout of a dc microgrid

The dc microgrid considered is schematically shown in Fig. As for a typical dc microgrid, it consists of the following mainelements:
• variable (nondeterministic) generations and, in this example, a wind turbine using permanent-magnet synchronous generator (PMSG); the maximum power output from the wind turbine is largely determined by the wind condition;
• controlled (deterministic) generation (e.g., a diesel generator or with ac grid connection); as shown in Fig, the dc grid in this example is connected to an external ac system via a dc-ac converter which provides bidirectionalpower-flow capability;
• variable loads with different characteristics; a number of ac and dc loads can be anticipated (e.g., ac loads via dc-ac inverters, dc loads via dc-dc converters, and direct-connected dc loads, etc.);
• energy storage (ES) system to accommodate the presence of variable generation and load, and the requirement of possible island operation (i.e., connection to the external ac system being lost)

Reference:
Lie Xu, Dong Chen. “Control and Operation of a DC Microgrid With Variable Generation and Energy Storage”. IEEE Transactions on Power Delivery, Vol. 26, No. 4, October 2011


The DC microgrid based on modular PV generation system

The DC bus coupled microgrid investigated in this paper is shown in Fig. 1. DC/DC converters for PV modules, a bidirectional DC/DC converter for battery, a bi-directional DC/AC converter and local loads share a DC bus. The modular photovoltaic generation system is the key element in this DC microgrid, which consists of three DC/DC converters with modular design and same ratings. These  modular converters transfer the power generated by PV arrays to DC bus. The battery with bi-directional DC/DC
converter is used to balance the power differences between PV power supplies and local loads in islanding mode. The local loads include the auxiliary power supplies for microgrid operations, such as control/monitoring of PV arrays, battery monitoring, control/driving of converters. The bi-directional DC/AC converter is used to realize the connection between DC microgrid and AC grid

Reference:
Li Zhan, Tianjin Wu, Yan Xing, Kai Sun, Josep M. Guerrero. “Power Control of DC Microgrid Using DC Bus Signaling”. Applied Power Electronics Conference and Exposition (APEC), 2011 Twenty-Sixth Annual IEEE.


Configuration of a dc microgrid application system

This DC microgrid have three photovoltaic solar plant, pne DC load, battery bank and microsource with DC/AC 3 -Phase Bi-directional Inverter, all components conected to DC bus of microgrid. Great !!

Reference:
T. F. Wu, C. H. Chang, L. C. Lin and Y. C. Chang. “DC-Bus Voltage Control for Three-Phase Bi-directional Inverter in DC Microgrid Applications”. Applied Power Electronics Conference and Exposition (APEC), 2012 Twenty-Seventh Annual IEEE


NEDO's grid-connection system projects

The New Energy and Industrial Technology Development Organization (NEDO) is Japan’s largest public R&D management organization for promoting the development of advanced industrial, environmental, new energy and energy conservation technologies. One of the important objectives of NEDO’s R&D is solving problems that arise when distributed and renewable resources are connected to power grids. These issues arise because the power output from most renewable energy resources fluctuates with weather conditions, and connecting them to traditional power grids may create power quality issues. Therefore, the development of energy management systems, energy storage applications and forecasting
methods is important for resolving connection issues. NEDO is promoting several grid connection related projects, as shown in Figure. In those projects, two microgrid-related projects are involved. After the year 2010, NEDO started several international smart community projects

Source:
Nikos Hatziargyriou. “Microgrids Architectures and Control”. 2014 John Wiley and Sons Ltd. ISBN: 978-1-118-72068-4.


when the priority is sun wind battery utility network

This simulation is about microgrid with solar and wind source, battery storage and utility network. It have cost differents and the simulation is para 96 time’s step. The distance between time’s step is configurable and it depend of characteristic of each source and all source in general. Made on Matlab of Math/Works Inc.

 


Impact of local balancing of Microgrids

Satisfaction of local consumption implies that the power produced by microgeneration is used to supply partly or wholly in-site consumption. In such a case, there is no requirement for separate metering of microsource generation (also called “net-metering”). However, on-site generation and on-site load need to be metered separately when microsource units appear as independent generators that sell all their production directly to the network and are not financially related to end consumers. In this case, local consumption is a market opportunity that can be easily overlooked by all players (see Figure). There are two main advantages of promoting local consumption satisfaction within a microgrid:

1. End consumers are provided with more choices in retail power supply.

2. Microsource operators have the possibility to obtain quasi-retail prices via selling locallyto minimize network charges.

The local retail market concept is therefore directly linked to the local consumption mechanism, which can also be seen as a two-sided hedging tool for both demand and supply players for reducing market risk: consumers can use the local market to hedge against high market price, while microsources can use the local market to hedge against low market price.

Source:
Nikos Hatziargyriou. “Microgrids Architectures and Control”. 2014 John Wiley and Sons Ltd. ISBN: 978-1-118-72068-4.


What is not a microgrid Sample cases

In Figure, the microgrid concept is further clarified by examples that highlight three essential microgrid features: local load, local microsources and intelligent control. In many countries environmental protection is romoted by the provision of carbon credits by the use of RES and CHP technologies; this should be also added as a microgrids feature. Absence of one or more features would be better described by DG interconnection cases or DSI (Demand Side integration) case.

Source:
Nikos Hatziargyriou. “Microgrids Architectures and Control”. 2014 John Wiley and Sons Ltd. ISBN: 978-1-118-72068-4.


large variety of scales of the microgrids

A microgrid appears at a large variety of scales: it can be defined at the level of a LV grid, a LV feeder or a LV house – examples are given in Figure. As a microgrid grows in scale, it will likely be equipped with more balancing capacities and feature better controllability to reduce the intermittencies of load and RES. In general, the maximum capacity of a microgrid (in terms of peak load demand) is limited to few MW (at least at the European scale, other regions may have different upper limits, see Chapter 6). At higher voltage levels, multimicrogrid concepts are applied, implying the coordination of interconnected, but separate microgrids in collaboration with upstream connected DGs and MV network controls. The operation of multi-microgrids)…

Source:
Nikos Hatziargyriou. “Microgrids Architectures and Control”. 2014 John Wiley and Sons Ltd. ISBN: 978-1-118-72068-4.


simulations load diagram electric

During operation a microgrid, sometimes; renewable energy sources and the external power grid, dispatched electric energy simultaneously. Sometimes, many sources is neccesary for supply to electric load. Also, all it, considering both economic and technical criteria. The figure represent la connection and disconnetion of sources for each state of performance of a microgrid. Too, it is applicable to other similar electric systems.


energy of each source accumulate

In a microgrid, each energy source is required according to the criterion of costs and production capacity. During the operation time, accumulative energy from each source is represented in the figure. Criteria of linear optimization has been used in this modelling and simulation. This allows determining the nominal capacity and the ability to respond to sudden requests. Made on Matlab of MathWorks Inc.


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.