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In this paper a torque calculation of a permanent magnet DC commutator motor (PMDCCM) by using FEM data is performed. For the FEM calculation of the torque a 2D FEM magnetic field calculation, as very suitable for this type of geometry, is performed. Therefore a proper modelling of the motor is required. The method used for the torque calculation using FEM data is the Weighted Stress Tensor (WST)...
In stand still frequency response, extrapolation in low frequency will be used to calculate Ld0 (initial value of d-axes inductance), Lq0 (initial value of q-axes inductance) and Ra (stator resistance).Because of dependency of generator parameters to this parameters, accuracy of these parameters for exact identification is so important. In this paper effect of stator resistance on generator parameters...
In this paper a novel method based on the rotor position sensor for real-time generating synchronous machine Etildeq waveforms and the corresponding application system are proposed. The proposed application system can output a few channels of sine signals whose frequencies and phases are the same with those of the involved synchronous machine Etildeq phasor. With the proposed application system, other...
This paper presents dynamic modeling and simulation of a doubly fed induction generator (DFIG) wind turbine based on space vector pulse width modulation (SVPWM) converter. SVPWM is applied to partial scale power electronic converters as grid side and rotor side converter. All power and control units are performed in PSCAD/EMTDC software. Dynamic response in grid connected mode for variable speed wind...
The significant increase of production of energy from renewable sources led to the necessity of developing new ways of exploration of the power systems. The evaluation of the intermittent of the renewable generation, which characterizes some of the renewable sources, such as wind power, becomes very important to assess its impact on the generation reliability of power systems. This paper studies and...
The use of wind power has been increasing rapidly over last few decades and according to all predictions this trend is likely to continue. At the same time need for better cost effectiveness of wind power plants has stimulated growth in wind turbinespsila size and rated power. As wind turbines grow in size they are subject to extreme structural loads and fatigue. In order to reduce such loads advanced...
Wind generation is one of the most important renewable energy technologies. The most common type of wind turbine is the fixed-speed directly connected to the grid. Faults in the power system can originate the disconnection of wind farms. Grid codes appear. Custom power systems, such as D-STATCOM and DVR, are needed for helping old wind farms to withstand the sag. DFIG with the appropriate converter...
Governments in many countries including UK & Ireland are incentivising a higher percentage of electric power from renewable sources. In many places achieving this objective is heavily dependent on wind power. Historically, networks developed to serve load and are weak in windy areas. Network development requires permissions and therefore takes many years. This paper explores equipment and analysis...
Recently, allocations of transmission losses have become a major issue in both regulated and deregulated systems. Two main reasons for this are performance and cost issues. Consequently, there have been a large number of investigations undertaken in the area of transmission loss allocation. The aims of this paper are to investigate several loss allocation methods and then choose the best method, or...
This paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. To assess the maximum degree of wind generation penetrability in full compliance with the safe operation of the system, it seemed necessary to investigate the reports of contemporary winds and their territorial correlations...
In this paper, a problem of optimal capacitor placement and conductor selection is solved for a nonuniform radial distribution system with lateral subfeeders. In this optimization problem the loads of the system is considered to be nonlinear. The voltage of each bus along the feeder after capacitor and conductor installation is calculated for each harmonic order. The total voltage and current harmonic...
A generic method for multi-objective optimization for bad data identification is presented based on multi-objective vector evaluated particle swarm optimization (VEPSO) algorithm. This multi-objective VEPSO is made adaptive in nature by allowing its vital parameters to change with iterations. This adaptability helps the algorithms to explore the search space more efficiently. After the bad data are...
The growing penetration of GD in distribution networks determines a complete redeployment of power flows along distribution feeders, thus causing altered voltage profiles and new issues in protection reliability. This paper addresses the issue of island opening operation, by using detailed models of GD sources and analyzing the frequency and voltage oscillations induced by islanding in different condition...
The stability of future power networks is getting influenced by the features of sustainable energy sources. Thus, a method of stability indication, which can combine the stochastic behavior of the renewable energy sources and the deterministic way of stability analysis, is of interest. This paper introduces an analytical method of small disturbance angle stability indication in future power systems...
This paper introduces the concept of dynamic modelling for wide area and adaptive power system protection. Although not limited to these types of protection schemes, these were chosen due to their potential role in solving a multitude of protection challenges facing future power systems. The dynamic modelling will be implemented using a bespoke simulation environment. This tool allows for a fully...
The conventional load flow methods for transmission systems could not be utilized for distribution systems, due to their especial characteristics. If methods like Newton-Raphson and fast-decoupled are used for distribution systems, the probability of their convergence would be low. Therefore, due to inherent characteristics of distribution systems, it is essential to develop the distribution version...
Dynamic model of a variable speed wind generation system connected to grid is developed, and its steady state and dynamic performance is explored. The performance under wind gust and three-phase fault has been studied and the amount of transient injection to the grid is also investigated. A control scheme that minimizes the transient injection through a thyristor controlled variable capacitance at...
Various ancillary services are needed in a deregulated power system to ensure the electricity to be delivered reliably and the system is operated securely. Spinning reserve is one of these ancillary services which a reasonable amount of such reserve is essential to satisfy system security constraints when the power system faces with a contingency. In this paper, Emergency Demand Response Program (EDRP)...
This paper proposes a novel differential protection technique of three-phase transformers using Wavelet Transforms (WTs). The Wavelet Transform is an efficient signal processing tool used in non stationary signals with fast transition studies (high frequency components). The three phase differential currents are the input signals used on-line in the proposed formulation. The performance of the proposed...
Reducing rail voltage and stray current corrosion all at once is one of the challenging problems in DC electrified rail transit systems. Stray current is the main reason of corrosion in the metallic parts located in the proximity of the railway. Choosing appropriate earthing scheme is an effective way to decrease corrosion intensity and providing safety for personnel. This paper discusses a possible...
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