Power Quality Issues Of A Grid Connected Micro Grid

Fig. 9(a) shows the DC-link voltage across the DC-link capacitor of the PV array. The DC-link reference voltage corresponds to maximum power point of the PV array. Fig. 9(b) shows the power demand by the load, and power flows from the grid and PV system generated power. As the PV system generated power could not meet complete power demand of load, remainining power is supplied by the grid. At 1secocond the PV system switched from partially shaded condition to uniform solar insolation. Thus, at this point power supplied by the inverter and grid also varies. Fig. 10(a) shows the grid current which is fully sinusoidal. Fig. 10(b) shows the inverter output current. Fig. 11 shows the performance of system under reactive load condition. In this study, a 500VA reactive load is considered. The figure shows the complete reactive power is supplied by the inverter. Thus the power factor of the system is maintained nearly at

The implications of this conclusion are positive for the electrification of Haiti. If this minigrid system is successful, it will provide great opportunities for improvements in standard of living. The viability of this minigrid system also demonstrates that alternative energy may be effective in Haiti and other similar countries. These countries should consider implementing minigrids or other renewable energy sources,

In Europe, around 300,000 houses are not interconnected to the main electricity grid (Lymberopoulos & Zoulias, 2008). These houses are located in remote areas such as islands and mountains. Currently, fossil fuel based generators do the electrification of these households. These generators are sometimes supplemented with renewable energy based systems (e.g. PV solar panels or wind turbines). The fossil fuel based generators face problems with onsite fuel availability, noise and local emissions. The renewable energy systems, on the other hand, face problems with the intermittency of the natural source, such as wind or sun. The disadvantages of both systems could be potentially overcome with the introduction of the artificial leaf technology

A single military base with its own energy resources or so-called “islanded micro grid operation” is based on the ability to operate independently from the larger electrical grid. In this case the power is produced on the base and can reliably maintain operations. Recent reports from the

Recently interest in Distributed Energy Systems (DES) is increasing, particularly onsite generation. This interest is because larger power plants are economically unfeasible in many regions due to increasing system and fuel costs, and more strict environmental regulations. In addition, recent technological advances in small generators, Power Electronics, and energy storage devices have provided a new opportunity for distributed energy resources at the distribution level, and especially, the incentive laws to utilize renewable energies has also encouraged a more decentralized approach to power

Significant changes of the structure of low voltage distribution system can be achieved by developing "microgrids" [2] coupled with appropriate energy storage and energy management

IEEE 1547 Standard for Interconnecting Distributed Resources with Electric Power Systems. This document provides a uniform standard for interconnection of distributed resources with electric power systems. It establishes criteria and requirements relevant to the performance, operation, testing, safety considerations and maintenance of the interconnection.

The characteristic curve of a SPV system varying with solar radiation and temperature does not match the characteristic curve of the load. In those cases, the power conditioning unit regulates the load’s voltage and current in such a way, that the SPV system is operated at its optimum operation voltage (VMPP) and current (IMPP).

This chapter defines distributed generation (DG), briefly describes why it is useful and in the end mentions the problems associated with its connection to the grid.

What was once a novelty; energy is now the ultimate necessity for any modern country. A sustain power grid is what separates a solvent nation from a third world country. The scenario of one of the three power grids failing would cause chaos to that area but would be sustainable with the capabilities of the remaining grid systems (ESSP 2015). A major sustain loss of power grid across the United States would interrupt commerce of the food chain via manufacturing and delivery of product, water systems, federal, state and local line of communications which would paralyze law enforcement, civil unrest would spread across the nation.

While working for Dover Chemical the largest assignment that I was given was to aid a contracting engineer with a power distribution project for the plant. Power distribution is the transfer of energy, or electricity, from one location to another. However In order to understand power transfer from generation to distribution it is important to understand the process from start to finish. AC (Alternating Current) is used for this transfer because of its ability to transmit over longer distance with lower losses by using transformers. Power is lost in transmission lines due to its resistance, the longer the transmission line the higher its resistance will be, however when using polyphase AC current we are able to change the voltage levels through the use of transformers. There are step-up transformers and step-down transformers both are used when transporting power from one location to another.

In this paper, IEEE 1547.4 standard (2011) is selected to propose microgrid standards for ECRA especially standard of stability of microgrids in different modes.

Abstract—Grid-connected inverters (GCI) are widely used to feed power from renewable energy distributed generators into smarter grids. Repetitive control (RC) enables such inverters to inject high quality fundamental-frequency sinusoidal currents into the grid. However, digital RC which can get approximately no tracking error of any periodic signal in steady-state whose period is known, cannot exactly track or reject periodic signal of frequency variations. Thus digital RC would lead to a significant power quality degradation of GCIs when grid frequency varies and causes periodic signal with non-integer periods. In this research paper a repetitive control scheme capable of frequency adaptation (FARC) at a predefined sampling rate is proposed to deal with all types of periodic signal of variable frequency. A fractional delay filter which is based on Lagrange interpolation is used to estimate the fractional period terms in RC. This proposed FARC controller offers the fast during process modification of fractional delay and fast revise of filter parameters, and then provides GCIs with a simple but very accurate existent time frequency adaptive control

Grid technology. Focus on high-capacity unit and network, but can also focus on the development of small-capacity unit. Small-capacity units and network are more difficult, but it can be other power generation combined. In recent years, the development of wind and solar technologies, can also be considered in conjunction with the tidal power, geothermal energy, thermal energy, hydropower, to solve the small-capacity unit grid difficult problem.

This work's MG has conventional generators and RES, PV and WT, related to the supply matter and DR formulations related to the consumer. The hourly generated power of the PV and the hourly wind generation related to the wind speed mentioned in (1) and (2). Also, the hourly wind speed mathematical formula is shown in (3) [29]