186,278 research outputs found
Complex-Array-Operation Newton Solver for Power Grids Simulations
No full textThis paper presents a robust and efficient technique for performing repeated power flow simulations of power networks. The method relies on a vector-based formulation of the power balance equations combined with a complex-array operation Newton solver. It is shown how the method is suitable for advanced simulations of power grids, such as probabilistic analyses, where a large number of scenarios have to be explored in reasonable simulation times. Applications to benchmark single phase networks as well as to unbalanced three phase grids are provided
Data-driven uncertainty analysis of distribution networks including photovoltaic generation
No full textThis paper investigates residential distribution networks with uncertain loads and photovoltaic distributed generation. An original probabilistic modeling of consumer demand and photovoltaic generation is presented that is based on the analysis of large set of data measurements. It is shown how photovoltaic generation is described by complex non-standard distributions that can be described only numerically. Probabilistic analysis is performed using an enhanced version of the Polynomial Chaos technique that exploits a proper set of polynomial basis functions. It is described how such functions can be generated from the numerically available data. Compared to other approximate methods for probabilistic analysis, the novel technique has the advantages of modeling accurately truly nonlinear problems and of directly providing the detailed Probability Density Function of relevant observable quantities affecting the quality of service. Compared to standard Monte Carlo method, the proposed technique introduces a simulation speedup that depends on the number of random parameters. Numerical applications to radial and weakly meshed networks are presented where the method is employed to explore overvoltage, unbalance factor and power loss, as a function of photovoltaic penetration and/or network configuration
Statistical simulation of Electric Vehicle behaviour applied to low voltage distribution network
No full textThe usage of Electric vehicles is increasing every day, and its penetration into the present electrical distribution network on large-scale needs to be investigated by the distribution companies to be future-ready and to provide good quality of electric supply. This article provides a statistical methodology to model electric vehicle charging behavior in a large network using real measurement data set. The vital information such as time of connection, duration of the connection, and power absorbed during the charging are extracted. The probability distribution of these extracted events is used to model 300 electric vehicle charging behavior whose integration with a non-synthetic low voltage European test network built using the real measurement data set is investigated for voltage distribution and the Voltage unbalance factor among the busses, feeders, and other elements present in the network. The numerical simulation framework is executed with Opendss for load flow analysis and MATLAB for statistical analysis and to invoke the load flow solver
Piece-Wise Linear (PWL) Probabilistic Analysis of Power Grid with High Penetration PV Integration
No full textThis paper aims at presenting a novel effective approach to probabilistic analysis of distribution power grid with high penetration of PV sources. The novel method adopts a Gaussian Mixture Model for reproducing the uncertainty of correlated PV sources along with a piece-wise-linear approximation of the voltage-power relationship established by load flow problem. The method allows the handling of scenarios with a large number of uncertain PV sources in an efficient yet accurate way. A distinctive feature of the proposed probabilistic analysis is that of directly providing, in closed-form, the joint probability distribution of the set of observable variables of interest. From such a comprehensive statistical representation, remarkable information about grid uncertainty can be deduced. This includes the probability of violating the safe operation conditions as a function of PV penetration
Estimating the Locking Range of Analog Dividers through a Phase-Domain Macromodel
No full textThis work describes an efficient method to estimate and compare the locking range of Injection-Locked-Frequency-Dividers. The method can be exploited during the design phase to explore rapidly how the locking range varies for many possible parameter settings and injection strategies
Linear Multistep Discretization Methods with Variable Step-Size in Nonlinear Wave Digital Structures for Virtual Analog Modeling
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A Versatile Surrogate Model of the Power Distribution Grid Described by a Large Number of Parameters
No full textThis paper aims to present a general-purpose Surrogate Model for the probabilistic analysis of power distribution grids with a large number of input parameters. The distinctive feature of the novel technique is the employment of the partial derivatives of output variables versus input parameters to tame the “curse of dimensionality” problem exhibited by prior surrogate model calculation techniques. The second important feature of the proposed Surrogate Model method is that it does not require any a priori assumption about the nature or statistical distribution of the input parameters. In fact, it can be applied whenever design parameters are deterministic variables as well as when they are uncertain and represented by continuous and/or discrete random variables. Relevant applications presented in the paper refer to the probabilistic analysis of the distribution grid in the presence of a large number of photovoltaic sources and electric vehicle charging stations
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