Application Of Dgs For Local Network Stability

A Power system is an connection of generators to load centres. Through H.V. electrical lines & in general is controlled mechanically. It can be divided into 3 subsystems: Generation, X’mission and Distribution-systems. The electric power demand is Growing and building of new generating units & transmission circuits is becoming difficult because of environmental & economic reasons. So, power utilities are forced to depend on utilization of existing generating units and to load existing lines close to their heating limits.

The parameters of this controller (PI- 1) can be decreased during the voltage sag in order to improve the performance of the proposed method.

So, the above issues can be applied to distributed power systems similarly, and the recent research focuses are summarized as follows:

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 emerging concept of MicroGrids or SmartGrids is aimed at changing the paradigm of the conventional power system in order to meet various challenges facing modern day society. To understand why the shift in paradigm is necessary, it is important to have a firm knowledge of the layout of conventional power systems as well as the energy challenges facing our society. A high level example of a conventional power system is shown in figure 1.

The grid, which includes transmission and distribution lines, is a critical aspect of the energy industry that has become antiquated in recent years. The first problem is caused by an increasing demand, 2.5% annually over the last 20 years, leaving the grid overused [gungor]. The second problem is the age of the infrastructure the average age of the power-grid transmission lines are 50–60 years [gungor]. Because the increase in demand and age of the infrastructure coupled with the nonlinear nature of the electric power distribution network have caused serious network congestion issues, which has caused several major blackouts [gungor]. In addition to network congestion, the existing power grid also is out-of-date in the following areas: communications, monitoring, fault diagnostics and automation which further increase the possibility of region-wide system blackout [gungor]. All the aforementioned problems of the “traditional” grid have been increasingly more difficult to meet in the 21st centuries demands, including power-grid integration, system stability and energy storage and an overall decrease in reliability [erol,gungor].

In a multi-terminal high voltage grid, some HVAC & HVDC network is connected though converter and inverter respectively. Parallel or simultaneous AC-DC long distance power transmission is possible by using this configuration. The system operator can automatically select the optimal set of ac/dc transmission lines parameter for satisfying TEP criteria i.e. supplying load forecasts, minimizing investment costs, and optimizing market operations that becomes suitable for practical application.

HVDC transmission may also be selected for other technical benefits. HVDC can transfer power between separate AC networks. HVDC powerflow between separate AC systems can be automatically controlled to support either network during transient conditions, but without the risk that a major power system collapse in one network will lead to a collapse in the second. HVDC improves on system controllability, with at least one HVDC link embedded in an AC grid—in the deregulated environment, the controllability feature is particularly useful where control of energy trading is needed.

Given the challenges encountered while employing conventional electrification methods, micro-grids are being seen as an alternative for providing electricity through a decentralised renewable energy generation and distribution. Decentralised electricity generation signifies ‘an electric power source connected directly to the distribution network or on the customer’s side of the meter’ (Gurtoo & Lahiri n.d.: 17). Micro-grids have the potential for improving energy access and can play a

In this topology, the number of power conversion stages is decreased, there by reducing the number semi conductor switches. So the conduction losses and switching losses are reduced. High frequency transformer is used for isolation because of its reduced size and weight such that it decreases the complexity of the micro inverter. Due to increased switching frequency , the series resonant tank is used to execute the soft switching at the turn on of the power switches to decrease the switching losses. The switching and conduction losses of the inverter are critically analyzed and methods are presented to calculate the size of the resonant components. Thus the outputs are simulated using

Optimal integration of renewable energy resources in data centers with behind the meter renewable generator

This paper proposes a new real and reactive power coordination controller for a unified power flow controller (UPFC). The basic control for the UPFC is such that the series converter of the UPFC controls the transmission line near the micro grid real/reactive power flow and the shunt converter of the UPFC controls the UPFC bus voltage/shunt reactive power and the DC link capacitor voltage. In steady state, the real power demand of the series converter is supplied by the shunt converter of the UPFC. To avoid instability/loss of DC link capacitor voltage during transient conditions, a new real power coordination controller has been designed. A new PSO based reactive power coordination controller has been designed to limit excessive voltage excursions during reactive power transfers. Matlab simulation results have been presented to show the improvement in the performance of the UPFC control with the proposed real power and reactive

A microgrid is introduced to resolve the issues with the economics and the resilience of power delivery systems. Microgrid loads get supplied by both the utility grid and on-site generation when connected to the utility grid. A microgrid is seen as an aggregated controllable load from the utility grid.

Present grid networks are oriented for conventional power generation but are not capable of handling the varied conditions and losses in transmission and inconveniences of power

Abstract: DC microgrid is the high quality electric power system focused on the development of renewable energy resources. The dc distribution system is connected to AC grid, Photovoltaic system and synchronous generator. Moreover, the power is transmitted through dc distribution line and is converted to required AC or DC voltages by load side converters. Those converters do not require transformers by choosing proper DC distribution voltage. The DC power line is 400V. This distributed design of load side converters also contributes to provide supplying high quality power. In this research, the configuration of DC microgrid system, control methods of distributed generation will be presented. Moreover, stand-alone system and grid connected system of DC microgrid will also be expressed. The model of DC microgrid system will be constructed with MATLAB/SIMULINK. Simulation results will be described.