31-01-2012, 04:50 PM
sir im engineering student need to give ppt on advanced micro grids...plz help me sir
31-01-2012, 04:50 PM
sir im engineering student need to give ppt on advanced micro grids...plz help me sir
04-02-2012, 12:44 PM
To get more information about the topic "Micro-grid full report " please refer the link below
https://seminarproject.net/Thread-micro-...9#pid56439
01-03-2012, 09:44 PM
[size=medium]pls send micro grid ppt
02-03-2012, 10:27 AM
to get information about the topic MicroGrid full report ppt and related topic refer the link bellow https://seminarproject.net/Thread-micro-...ull-report https://seminarproject.net/Thread-microgrid
14-03-2012, 12:52 AM
[size=medium]please send micro grid ppt at the earliest... please.. it is urgent
14-03-2012, 10:11 AM
to get information about the topic "Micro Grid" full report ppt and related topic refer the link bellow
https://seminarproject.net/Thread-micro-...ull-report https://seminarproject.net/Thread-microgrid
27-07-2012, 03:41 PM
Micro Grid Micro Grid.docx (Size: 2.3 MB / Downloads: 225) INTRODUCTION This paper presents an APC used to improve the power quality in a microgrid. The attention will be mainly focused on the innovative control strategy, which allows injecting energy in the micro grid, compensating the current harmonics, correcting the power factor and balancing the supply voltage at the PCC. A micro grid is different from a main grid system which can be considered as an unlimited power so that load variations do not affect the stability of the system. On the contrary, in a micro grid, large and sudden changes in the load may result in voltage transient of large magnitudes in the AC bus. Moreover, the proliferation of switching power converters and nonlinear loads with large rated power can increase the contamination level in voltages and currents waveforms in a micro grid, forcing to improve the compensation characteristics required to satisfy more stringent harmonics standards. Concept of Micro grid: Micro grids are small-scale, LV supply networks designed to supply electrical and heat loads for a small community, such as a housing estate or a suburban locality, or an academic or public community such as a university or school, a commercial area, an industrial site, a trading estate or a municipal region. Micro grid is essentially an active distribution network because it is the conglomerate of distributed generation systems and different loads at distribution voltage level. The generators or micro sources employed in a Micro grid are usually renewable/non-conventional Distributed generation and Micro grid concept 3 DERs integrated together to generate power at distribution voltage. From operational point of view, the micro sources must be equipped with power electronic interfaces (PEIs) and controls to provide the required flexibility to ensure operation as a single aggregated system and to maintain the specified power quality and energy output. This control flexibility would allow the Micro grid to present itself to the main utility power system as a single controlled unit that meets local energy needs for reliability and security. Computing Resource Simulation: For Grid applications, many of which are compute intensive, accurate modeling of CPU speed is critical. Therefore, our first simulation module focuses on simulating the execution speed of various processors. For each virtual host, the speed of its processor is stored as a GIS attribute on the host record (see Figure 3). Given the virtual host CPU speed, the physical processor speed can be used to calculate the simulation rate, which in this case yields an actual CPU fraction which should be allocated for this Grid simulation. This CPU fraction is then divided across each process on a virtual host. The resulting fractions are then enforced by the local Micro Grid CPU scheduler. Power quality: The power quality of power supply of an ideal power system means to supply electric energy with perfect sinusoidal waveform at a constant frequency of a specified voltage with least amount of disturbances. Power quality is an issue that is becoming increasingly important to electricity consumers at all levels of usage. Sensitive equipment and non-linear loads are now more commonplace in both the industrial commercial sectors and the domestic environment. Because of this a heightened awareness of power quality is developing amongst electricity users. Occurrences affecting the electricity supply that were once considered acceptable by electricity companies and users are now often considered a problem to the users of everyday equipment. However the harmonic is one of the major factor due to which none of condition is fulfilled in practice. The presence of harmonics, disturbs the waveform shape of voltage and current, and increases the current level and changes the power factor of supply and which in turn creates so many problems. Harmonics: Harmonics are periodic sinusoidal distortions of the supply voltage or load current caused by non-linear loads. Harmonics are measured in integer multiples of the fundamental supply frequency. Using Fourier series analysis the individual frequency components of the distorted waveform can be described in terms of the harmonic order, magnitude and phase of each component. The electricity is produced and distributed in its fundamental form as 50 Hz in India. A harmonics is defined as the content of signal who’s frequency is integer multiple of the system fundamental frequency. Due to harmonic effect the sinusoidal waveform is no longer have stand and it become non-sinusoidal or complex waveform. The complex waveform consists of a fundamental wave of 50 Hz and a number of other sinusoidal waves whose frequencies are integral multiple of fundamental wave like 2f(100hz). 3f (150 Hz), 4f (200 Hz) etc. Wave having frequency of 2f, 4f, 6f etc are called the even harmonics and those having frequency of 3f, 5f, 7f etc are called as odd harmonics. When fundamental frequency is super imposed with high-level harmonics, it results into complex wave and which is non sinusoidal. When non-linear load draws current, that current passes through all of the impedance that is between the load and the system source (See Figure 4). As a result of the current flow, harmonic voltages are produced by impedance in the system for each harmonic. These voltages sum and when added to the nominal voltage produce voltage distortion. The magnitude of the voltage distortion depends on the source impedance and the harmonic voltages produced. If the source impedance is low then the voltage distortion will be low. Multi level inverters: The multilevel inverters have gained considerable attention over the past decade for high-voltage and power applications in industries. The primary advantage of multilevel inverters is their smaller output voltage step, which results in high power quality, lower harmonic components, better electromagnetic compatibility and lower switching losses. There are four different types of multilevel inverters: the diode-clamped inverter, the flying-capacitor-clamped inverter, the switch-clamped inverter and the cascade multilevel inverter. Diode-clamped inverters were proposed previously and have been successfully used in the high-power motor drive and the active power filter. However, the disadvantages of diode-clamped inverters are that many power semiconductors need to be used in the circuits and the control scheme is complex. |
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