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Due to the incremental demands for electrical energy, Distributed Generator (DG) sources are prominent in distribution systems. At the same time, the Locations and Capacities of DG sources have profoundly influenced the system losses in a distribution network. In this paper, a Hybrid algorithmusing Power Loss Index (PLI) & Genetic Algorithm (GA) presented for optimized Location and sizing of DG...
Performance analysis of STATCOM is presented for 400kV Indian grid level application. The paper contains the investigation based on simulation carried out in PSS/E software. The principles of STATCOM operation along with basic concepts of power system voltage stability are addressed. PV/QV analysis shows the impact of STATCOM on steady state or small disturbance voltage stability. Large disturbance...
Due to the inherently distributed and heterogeneous nature of the microgrids, distributed control can be a promising approach to improving the stability, reliability and scalability of the microgrids compared with centralized control strategies. This work studies the distributed reactive power sharing problem for a microgrid with connected AC inverters. Under the lossless assumption of the microgrid,...
The increasing proliferation of distributed generations (DGs) in distribution networks has brought several management and operation challenges. To improve energy efficiency and voltage profiles of the distribution grids under different operating conditions, this paper propose a distributed optimal reactive power control solution combined with gradient algorithm. In the proposed method, each DG or...
One of the biggest threats for the security of power grids are congestion of cross-border lines and congestion in the network itself as result of parallel flows. Nowadays, occurrence of congestion is a result of limited network transfer capacities as a direct consequence of increased power transactions. One of the reasons for cross-border congestions are the unreal cross-border capacities calculations...
In this paper, a competitive bidding based congestion management strategy is developed for a pool type electricity market model. The proposed congestion management strategy alleviates the transmission congestion by using rescheduling both the real and reactive power output of generators. The separate bids for real and reactive powers are invited from all participating generators in the congestion...
Distributed Generation (DG) has gained relevance In Medium Voltage (MV) / Low Voltage (LV) power grids worldwide. One of the main drawbacks related to high penetration of DG plants is represented by abrupt voltage raises. Such an issue typically occurs in the presence of either low demand conditions or high power production from renewable sources. This work is focused on the online management of distributed...
This paper deals with a voltage disturbance generator output characteristics. Usually a microgrid is connected to utility grid through STS to disconnect in case of fault occurrence. The STS should be opened in case of outage, however, it may be connected in case of voltage sag occurrence. The magnitude of surge or over current through the STS is determined by the dip of the sag. The voltage disturbance...
This paper discussed the tuning process of the power system stabilizer (PSS) for a nuclear turbine-generator excitation system. By measuring the non-compensated phase-frequency characteristic of the excitation without PSS, and through calculation and critical gain test, the PSS parameters are determined. Through step response and anti-regulation experiment, the effectiveness of the PSS is verified.
The foreseen high penetration levels of wind energy will have serious implications on frequency stability, hence developed control methods of wind turbine and alternative technologies including energy storage should enable the provision of frequency support by wind power. Active research is ongoing to investigate the possibility of collecting and transmitting offshore wind power through low frequency...
this study evaluates the impact of wind power generation connected to distribution systems. Three load profiles (residential, commercial and industrial) connected to the distribution network were analyzed considering the impact on voltage levels for different wind speeds and wind generator control strategies. The wind generator model is based on doubly fed induction generator (DFIG) and were developed...
This paper presents results of a heuristic optimization method for parameterization of decentral reactive power control, which can be used to improve static voltage quality in distribution grids. With an optimized Q(V)-curve it is possible to significantly reduce the additional reactive energy and accomplish lower losses in the grid while keeping the voltage within the specified limits. In this paper...
This paper presents a frequency control mechanism for an AC system through the active and reactive power loops of a VSC-HVDC system. The proposed scheme makes use of the reactive power loop for inertia support by exploiting the voltage-power sensitivity of loads, and active power droop control has been used to provide governor-like support following the large-disturbance. The performance of the presented...
This paper presents a novel approach, which identifies a buffer zone around a given study system and replaces the external system with an equivalent. The aim is to obtain a reduced system, which is suitable for assessment of long-term voltage and frequency dynamics in the study system. First, the proposed methodology ensures that all components, which are impacting the voltage profile of the study...
The present paper proposes an innovative control scheme for a fully rated wind generating unit equipped with a permanent magnet synchronous generator. The main objective of this control strategy is that of allowing a decoupled and dynamically performing control of active power (by the MPPT curve) and reactive power at the point of interconnection to the grid. Moreover, the control will be able to...
This paper aims to propose a secondary control algorithm based on Fuzzy Logic to adjust frequency and voltage in islanded microgrids. It is well-known, that, when a microgrid changes its operation from grid-connected to islanded mode, the time domain variability of the loads will change the frequency and voltage profiles of the system. In this sense, the operation of the system might become unsafe...
The large scale connection of power generation in distribution networks causes deregulation in power system networks. This paper focuses on studying the voltage changes at each node of the distribution network before and after the insertion of wind turbines as power generators, and also proposes two optimal voltage control methods in order to maintain a stable voltage profile. Results of the simulations...
Distribution networks are increasingly hosting embedded generators, most of them converting renewable energy primary sources. These units are usually interfaced with the main network by means of static power converters. Grid codes have recently introduced stabilizing functions to engage distributed plants in supporting the main system stability during network events and consequent voltage/frequency...
In recent years, there has been a large increase in power demand without corresponding increase in power generation. With the issues around global warming, the use of renewable energy such as wind and solar has gained popularity. Renewable energy is clean, sustainable (will never run out), environmentally friendly. In addition, it requires a relatively low maintenance and running costs. Many countries...
In this paper the zone controller is presented which regulates the reactive power-voltage characteristic (Q-V) of the zone pilot node by altering the reactive power outputs of power plants within the zone. As far as the zone is self-sufficient regarding reactive power needs, the generation is adapted to fit consumption and quasi-independent operation is achieved. As soon as limits are reached the...
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