Mohamed Hassan Ahmed

Probabilistic Distribution Load Flow With Different Wind Turbine Models

This paper presents a novel probabilistic distribution load flow (PDLF) algorithm to study the effect of connecting a wind turbine (WT) to a distribution system. This probabilistic approach is used to capture the stochastic behavior of the generation of WTs. Three different models of WTs are developed to be embedded in the PDLF. Consequently, a probabilistic approach to evaluate the impact of wind penetration into distribution systems is developed. Furthermore, the effect of WT penetration on feeder losses, voltage profile and substation powers is presented.

Stochastic Unit Commitment with Wind Generation Penetration

Abstract This article presents a new algorithm for analyzing the effects of wind generation uncertainties on short-term power system operation. Monte Carlo simulation is used to obtain a set of wind generation scenarios, and then the scenario reduction algorithm is applied to obtain a reduced set of scenarios. These reduced scenarios are then incorporated into the unit-commitment problem formulation with a locational marginal price based electricity market settlement and a dispatch model to examine the effects of wind generation on electricity market prices, load cleared, social welfare, and system capacity.

Stochastic analysis of wind penetration impact on electricity market prices

The intermittent nature of wind generation makes its operation and planning a complex problem and there is a need for the current analytical models to consider this uncertainty in generation appropriately. This paper focuses on developing appropriate mathematical modeling tools to examine the effect of wind generation on power systems. A stochastic wind generation profile is considered and Monte-Carlo simulation is used to simulate different scenarios of power generation. Subsequently, stochastic Uniform Market Price (UMP) is developed by incorporating the different reduced scenarios of wind power generation. Using the consequent Unit Commitment (UC) type model so developed, that incorporates market constraints and wind generation effects. The effect of changing the wind farm power capacity has been studied as well as the effect of the wake effect on off shore wind turbines.

Analysis of uncertainty model to incorporate wind penetration in LMP-based energy markets

This paper presents a mathematical modeling framework to examine the effect of wind generation on power systems. The work considers penetration of wind generation sources using a stochastic wind speed profile to obtain different scenarios of wind power generation. This is included in an appropriate scenario reduction procedure to classify the wind generation into specific levels based on wind speed and hence reduce the number of probabilistic combinations. A stochastic Locational Marginal Price (LMP) energy market model which incorporates wind power generation scenarios is then proposed. This model includes unit commitment constraints, transmission constraints and wind generation effects to examine the impact of wind generation on price settlement, load dispatch, and reserve requirements. The work further examines how the LMP market is affected by wind farm capacity when wake effect is considered.

Analysis of fault current contribution from inverter based distributed generation

This paper presents two analytical frameworks to study the fault current contribution from inverter based distributed generation (IB-DGs) in transient and steady state conditions. The developed models can be used to analyze the fault response of IB-DGs in active distribution networks. The steady state analysis of fault current contribution from IB-DGs is calculated using the forward-backward sweep method, whereas the transient model for the IB-DGs is developed using the IB-DG differential equations. The results of the both models are validated by PSCAD simulations.

Transformer Health Index estimation using Orthogonal Wavelet Network

The Health Index represents a practical tool that combines the results of operating observations, field inspections, and site and laboratory testing to manage the asset and prioritize investments in capital and maintenance plans. In this paper, the Orthogonal Wavelet Network is used to estimate transformer Health Index using various transformer test results. The idea is to build a tool that can be used to assign a representative health index to each transformer based on various transformer test results. The main purpose of this research is to develop a reliable health index for substation transformers. The proposed transformer health index will provide assessment of the transformer health condition which will be useful for maintenance, ensuring optimum transformer performance, increased efficiency and also increased expected life time.

Inclusion of Wind Generation Modeling into the Conventional Generation Adequacy Evaluation

Wind energy has become a significant portion of power generation resources, consequently its variability and uncertainty introduces various challenges for both the operation and planning of power systems. One of the great challenges of integrating wind energy in power systems can be seen from the reliability assessment perspective. Indeed, there is an ongoing recognized need to study the contribution of wind generation to overall system reliability and to ensure the adequacy of generation capacity. With respect to the evaluation of the reliability of power systems incorporating wind energy, a variety of criteria and techniques have been developed over the years. This paper is dedicated to reviewing the literature pertaining to generating system adequacy assessment in general and with regard to wind energy in particular. This paper firstly reviews the concepts and related aspects of generating system adequacy assessment, it also includes detailed description of the involved elements and the available widely commonly-used techniques. Then, it discusses the main issues arising when implementing wind generation into the adequacy assessment of generating systems. Moreover, the paper surveys the previously reported works that have proposed to involve wind generation into adequacy assessment.

Evaluation of the environmental impact of wind generation penetration

This paper presents a methodology to evaluate the environmental impact of wind generation penetration into electrical power system. A set of historical wind speed data is used to obtain different wind speed clusters which are used by Monte-Carlo Simulations to generate different daily wind speed profiles-scenarios. The Forward Selection algorithm is used to obtain a reduced set of scenarios. These reduced scenarios are then incorporated into a unit commitment model that analyzes the impact of wind generation penetration on the operation of conventional plants and on the resulting total system emissions. The solution of the unit commitment model is studied for different cost functions including the minimization of the total system emission. The relationship between changing the emission caps and the penetration level of wind energy is also investigated.

A novel Newton-Raphson algorithm for power flow analysis in the presence of constant current sources

This paper presents a version of the Newton-Raphson (NR) algorithm that has been modified to provide a means of facilitating the power flow analysis of loop systems in the presence of current sources that rely on current controlled inverters, such as distributed generators (DGs). The modifications entail the inclusion of the current elements of current sources in the Jacobian matrix of the NR algorithm. The effect is to enable current controlled sources to be modeled directly in the power flow algorithms without the need for converting their currents to the corresponding power components, which is the traditional practice in power flow algorithms. The proposed algorithm has been tested on an IEEE 14-bus system. For loop systems with current controlled sources, the test results show that using this algorithm for power flow analysis offers enhanced accuracy.

Impact of integrating PEV and renewable sources on power system reliability assessment

The electrification of vehicles is now considered an effective solution that will reduce fuel consumption and emissions as well as increase energy security through the diversification of available energy sources. The electric energy generated from low-emission renewable resources will play a vital role to meet the electricity needs of the transportation sector and will also address concerns about shifting emissions from the transportation sector to the electricity generation sector. This paper proposes a new approach to evaluate the power system reliability indices incorporating plug-in electric vehicles. The proposed method relies on developing virtual scenarios that cover all possible occurrences for normal demand, conventional generation, renewable resources, and plug-in electric vehicles demand. These scenarios are generated using Monte Carlo Simulation and Marcov Chains.