According to [40], locating DG units to minimize losses is similar to locating capacitor banks to reduce losses. The main difference between both situations is that DG may contribute with active power and reactive power (P and Q). On the other hand, capacitor banks only contribute with reactive power flow (Q). Mainly, generators in the system operate with a power factor range between 0.85 lagging and unity, but the presence of inverters and synchronous generators provides a contribution to reactive power compensation [49].
The optimum location of DG can be obtained using load flow analysis software, which is able to investigate the suitable location of DG within the system in order to reduce the losses. For instance: if feeders have high losses, adding a number of small capacity DGs will show an important positive effect on the losses and have a great benefit to the system. On the other hand, if larger units are added, they must be installed considering the feeder capacity boundaries [3].
3.6.3 Impact of DG on Harmonics
A wave that does not follow a “pure” sinusoidal wave is regarded as harmonically distorted. This is shown in Fig. 2.6.
Harmonics are always present in power systems to some extent. They can be caused by for instance: non-linearity in transformer exciting impedance or loads such as fluorescent lights, AC to DC conversion equipment, variable-speed drives, switch mode power equipment, arc furnaces, and other equipment.
Fig. 3.7 Comparison between pure sinusoidal wave and distorted wave [17]
Harmonic order
Allowed Level Relative to fundamental
(odd harmonics) *
< 11th 4%
< 11th to < 17th 2%
< 17th to 23...
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...Q types. The most commonly used DG model is the PQ model [38]. In this work, the PQ-DG units are represented as a negative PQ load model delivering active and reactive power to a distribution system. The DG reactive power can be calculated by the following equation:
Q_DGi=P_DGi ×tan(cos^(-1) (PF_DGi )) (4.21)
4.6 METHODOLOGY
In this chapter emphasis is laid so as how to locate the DG in the distribution system. The main problem here is that the system is already designed therefore we cannot design a new system, a new grid cannot be designed. For this purpose we used optimization techniques which are run in the software of MATLAB version 2012a. In this software we made a coding and we simulate the program to get result.
Figure 4.1 Methodology to solve the problem
My knowledge of engineering is reasonable and includes transformer substations, power plants, power distribution and transmission systems, industrial motor control and PLC programming, protective relay coordination, FACTS devices, grounding systems, Matlab programming and project management. In addition, I possess practical experience performing power flow, short-circuit and relay coordination analyses while using a power system modelling software such as ETAP, EDSA, DigSilent and CYME. Consequently, the aforementioned experience and solid engineering education along with your training will allow me to provide support to operating and new
In order to minimize the total shipping costs in the Darby distribution system, linear programming can be used.
A electric grid works as a power distribution system and carries electric powers through different power lines. Since grid cannot store any power anyplace within the system. We got several customers consuming megawatts of power at any moment. At that very same moment, we have got dozens of power plants manufacturing precisely the
The emergence of the Microgrids came after realizing that the architecture of the electricity grid existing nowadays (Figure 1) is getting obsolete, since it is based on the idea of a top-down system, which is predicated on unidirectional energy flows. [ASMUS09]
ABSTRACT. In this modern science world, the usage of power is very high. As the usage is increased, the power demand is also gets increased. In order to comprise/compensate the power demand, different forms of power sources are preferred. Dispatchable energy resources (non-renewable energy sources) are the sources can be turned on and off in short amount of time and it is generated from different techniques. Non-dispatchable energy resources (renewable energy resources) includes the nuclear power plants, hydroelectric plants, wind and wave energy resources. The Distributed Energy Resources (DER) typically use these renewable energy sources, including small hydro, biomas, solarpower, windpower and geothermal power for an electric power distribution system and DER is coordinated within a microgrid. A
The problem with this arrangement is the switching of Power between Local Utility and the Self owns generator. Whenever local utility is off, Generator must be turned on and inversely, for economical operation. it is the requirement that generator must be turned off when utility’s supply is again restored.
“U.S. Energy Information Administration - EIA - Independent Statistics and Analysis." Electric Power Monthly. U.S. Energy Information Administration, Apr. 2014. Web.
Electricity blackout is a shortage of an electric power or long term loss of the electric power in the particular area. Cause for an electricity blackout is in an electricity network, which includes faults at power stations, damage to electric transmission lines, substations or other parts of the distribution system, a short circuit or the overloading of electricity
Over the past few decades, there has been an increasing use of induction generator particularly in wind power applications. In generator operation, a prime mover (turbine, engine) drives the rotor above the synchronous speed. Stator flux still induces currents in the rotor, but since the opposing rotor flux is now cutting the stator coils, active current is produced in stator coils, and motor now operates as a generator, and sends power back to the electrical grid. Based on the source of reactive power induction generators can be classified into two type namely stand-alone generator and grid-connected induction generator. In case of stand-alone IGs the magnetizing flux is established by a capacitor bank connected to the ma...
Harmonics are sinusoidal component of periodic wave having an frequency that is an integral multiple of fundamental frequency.
...bjectives: The focus of this research proposal is to develop of a microgrid management system for reliable operation which will be incorporated with modeling, controlling, and power management of microgrid applications. Toward this proposal a theoretical investigation of the basic function of a feeble grid will be presented. A novel grid management strategy under changeable loads will be proposed for power management. Simulation work and experimental test will also carry out to demonstrate and validate the proposed control system for the operational improvement of the DG networks.
It automatically places the wind turbine boxes wherever required the communication is most important in this model and it can be achieved using the waterfall model. Because especially for this types of projects there should be well defined plan where everything goes as per th scheduled plan because there should be alert to the operator if there is any problem.
The use of digital computers for power system relaying has been proposed long time ago in [1]. Discrete Fourier transform (DFT) was one of the first algorithms that have been proposed to be used in digital relaying. DFT has been the focus of many researched due to its simplicity and its relevant properties. Variations of the DFT have been proposed. This includes the short window, long window and the symmetrical component DFT [2]. DFT has many advantages compared to other types of transforms. In this short report the DFT will be reviewed. An emphasis will be given on the DFT as compared to the usual Fourier transform. The use of DFT in relaying will be outlined and explained. The frequency response of the DFT will be sketched out and stressed. The report ends with the advantages and the disadvantages of the DFT used in power system relaying.
Small renewable units should be installed at rural areas and big units near to the cities.