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The importance of parasitic parameters in the study of a dynamical system is brought out in this work. The neglect of these parameters in the context of invariant manifolds for a multi machine power system for transient stability is studied. Singular perturbation approach is used for the calculation of critical clearing time of a large disturbance fault using equilibrium and invariant manifolds. It...
The integration of the renewable power generation into the existing grid has been increased significantly and it is expected to be increased further in near future. The placement of renewable power generation units can be done accordance with reactive power loadability and it has to be taken care during the optimal placement. In this paper, a particle Swarm Optimization (PSO) based optimal placement...
False tripping of distance relays on load encroachment may lead to cascade tripping and subsequent blackouts. Hence relays should be supervised to avoid tripping on load encroachment. In this paper, an algorithm based on Decision Tree (DT) is proposed for the differentiation of load encroachment from fault. DT is formulated using Transient Stability Margin (TSM) of generator angles as an attribute...
Power system is highly nonlinear system whose dynamic performance is influenced by a wide array of devices with different response rate and characteristic from a control theory point of view. In this paper optimum PSS has been designed with the help of different types of objective functions. For this purpose, algorithms using novel search method based on splitting the range of variables have been...
This paper investigates the transient stability of power systems under the framework of complex network theory. The studied power system is assumed to be singularly perturbed so that the corresponding reduced-order system is a Kuramoto-oscillator system in complex network theory. A condition is presented to guarantee the bounded synchronization of reduced system with an arbitrary topology so that...
The working performance of an electric machinery can be improved by adopting magnetic slot wedge on the stator or rotor. To investigate the influence of the magnetic slot wedge on magnetic field distribution and the saturation reactance of a turbo-generator, a 2-D mathematical model for electromagnetic field of a 150MW air-cooled turbo-generator has been established by considering two different types...
In this paper, a novel algorithm is proposed for optimal operation of microgrids considering the occurrence of faults or recovery from faults, auto-configuration. The objective of the proposed algorithm is to minimize the operation of the microgrid while ensuring stability. The auto-configuration is defined as the capability of the system to update the status of all components and reschedule healthy...
Traditionally, ancillary market is supported by a lot of conventional generators to produce or use reactive power with the purpose enhance voltage stability. However, in recently years, with the penetration of new wind generations (Double Fed Induction Generator (DFIG) and Direct Drive Synchronous Generator (DDSG)) and through different set of control possibility, wind power plants are able to partly...
Transient Stability Constrained Optimal Power Flow (TSCOPF) constitutes one of the most computational-intensive applications; it is used for power system preventive control against blackouts triggered by transient instability after a contingency. In this paper, a novel Optimal Power Flow (OPF) is proposed by adding the Transient Stability (TS) constraints into the conventional OPF problem, a Teaching-Learning-Based...
Increased penetration of renewables will require significant regulating reserves, so there is a need to re-think the traditional operating paradigm: supply follows demand. Recent work has expanded the role of flexible and controllable energy resources, such as energy storage and dispatchable demand, to regulate power imbalances and stabilize grid frequency. However, as shown in this paper, the large-scale...
Renewable technology based Micro Grid (MG) are mostly implemented with power electronic devices. Those MGs have no or very small aggregated physical inertia, depending on the generation technology used. Reduction in system inertia may have negative influence on stability of the system where the MG is integrated. Conversely power injection from MG might reduce line congestion, stress on synchronous...
In most countries, electricity is bought and sold at regulated and non-regulated prices. Non-regulated prices are mainly set on the wholesale electricity market and can significantly increase during peak periods due to input of more expensive generation. Another problem, which leads to an increase in prices on the market, is to achieve the carrying capacity of certain sections that does not allow...
With the growth of new energy resources and the increasingly complexity of power gird and operation condition, a method for intelligent recognition of transient instability pattern based on power grid topology is proposed in this paper. On the basis of the recognition of Dominant Instability Generator Group, a transient stability assessment algorithm which merely uses steady-state information is presented...
This paper presents a method to predict the transient voltage stability of power system based on the heuristic energy function method. First of all, an energy function including the three-order generator model and the simplified one-order induction model is constructed, according to the law of conservation of energy. Then a heuristic method is applied to identify the voltage related controlling unstable...
Focused on a non-electromechanical oscillation issue in Gansu province under islanding operation condition, this study investigated the possible reasons about the occurrence of oscillation by simulating the actually fault proceed and analyzing the corresponding recorded curves. It could be confirmed that unsuitable speed governor parameters of major generators were a significant reason to cause unstable...
Feed-in-tariffs (FiTs) have been reduced due to combinations of economic and technical reasons. So, existing and new rooftop-photovoltaic (PV) owners are left with the option to either concede the low value arrangement or to use battery storage to maximise their self-consumption, and so minimise their electricity cost. This paper explores the effect of increasing penetration of residential battery...
Utilizing of the power system stabilizer (PSS) is a common approach to eliminate the low frequency power swings. The phase lag that must be compensated by the PSS to increase the damping of the system efficiently should be carefully obtained from the excitation system; but, the uncertainty in the excitation system data is an unavoidable issue and must be eliminated. This paper utilizes a comparative...
Starting an aircraft engine with an electrical machine has been one of the major trends for future aircraft. This paper studies the stability of a permanent-magnet machine (PMM) based aircraft starter/generator (S/G) system. Using control-to-output transfer functions, the stability analysis of this S/G system is thoroughly studied. The impact of the key parameters including the control parameters...
The paper presents an analysis of the economical and technical impact of Water Network Loads (WNLs) on the operation of power systems. The paper also proposes an iterative technique to solve both a unit commitment problem with the inclusion of conventional power generation, wind power and WNLs and a N-1 contingency analysis based on time-domain simulations. At each iteration, if the WNLs schedule...
The high voltage direct current (HVDC) transmission line known as the Pacific DC Intertie (PDCI) has shown to be a potentially important actuator for retaining small-signal stability of the western North American Power System (wNAPS) for large contingencies. However, certain wNAPS damped oscillatory line flows and generator rotor speeds may be adversely affected by PDCI modulation subject to particular...
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