Topic
Power-flow study
About: Power-flow study is a research topic. Over the lifetime, 8091 publications have been published within this topic receiving 155053 citations. The topic is also known as: load-flow study.
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10 Jun 2004
TL;DR: In this article, the model initialization of the induction generator for the wind power generation is investigated and the machine model is studied from the perspective of slip and reactive power calculation and tested for various cases.
Abstract: Model initialization of the induction generator for the wind power generation is investigated. Incorrect initialization may lead to numerical instability problems, not to mention erroneous result from dynamic simulation. The machine model is studied from the perspective of slip and reactive power calculation and tested for various cases. The dynamic reactive power calculation in well-know software package is discussed and the deviation of dynamic reactive power from the steady state reactive power is highlighted
38 citations
03 Sep 2015
TL;DR: A novel approach to modeling the nonlinear steady state behavior of power grids in terms of equivalent circuits with currents and voltages as the state variables that is a step toward unifying transient and steady state models is proposed.
Abstract: Steady state analysis of power grids is typically performed using power flow analysis, where nonlinear balance equations of real and reactive power are solved to calculate the voltage magnitude, phase, and power at every bus. Transient analysis of the same power grids are performed using circuit simulation methods. We propose a novel approach to modeling the nonlinear steady state behavior of power grids in terms of equivalent circuits with currents and voltages as the state variables that is a step toward unifying transient and steady state models. A graph theoretic formulation approach is used to solve the circuits that enables incorporation of switch models for contingency analyses. Superior nonlinear steady state convergence is demonstrated by use of current as a state variable and application of circuit simulation methods. Furthermore, current and voltage state variables will offer greater compatibility with future smart grid components and monitors.
38 citations
TL;DR: In this article, the authors present a method to quantify and rank transmission system components by their importance for system reliability under different load scenarios, and rank each component by three separate importance indexes based on its expected outage rate and impact on: 1) system security margin; 2) load supply; and 3) generation units.
Abstract: This paper presents a method to quantify and rank transmission system components by their importance for system reliability under different load scenarios. Each component is ranked by three separate importance indexes based on its expected outage rate and impact on: 1) system security margin; 2) load supply; and 3) generation units. By studying these three interests individually, a more complete view of the risks to system reliability can be assessed. The method is demonstrated on a detailed power system model (7000 components) of a significant part of the Great Britain transmission system at 400 and 275 kV. The results show how sensitive the component indexes are to the load scenario. The method provides an input for decision-making when planning maintenance and new investment and can be used as a complement to deterministic criteria.
38 citations
TL;DR: Effectiveness of the SOA has been tested for optimized reactive power control of an isolated wind–diesel hybrid power system model and the performance of the proposed controller, with the influence of signal transmission delay, has been investigated.
Abstract: Seeker optimization algorithm (SOA) is a novel heuristic population-based search algorithm based on the concept of simulating the act of human searching. In SOA, the acts of human searching capability and understanding are exploited for the purpose of optimization. In this algorithm, search direction is based on empirical gradient by evaluating the response to the position changes and the step length is based on uncertainty reasoning by using a simple fuzzy rule. In this paper, effectiveness of the SOA has been tested for optimized reactive power control of an isolated wind–diesel hybrid power system model. In the studied power system model, a diesel engine based synchronous generator (SG) and a wind turbine based induction generator (IG) are used for the purpose of power generation. IG offers many advantages over the SG but it requires reactive power support for its operation. So, there is a gap between reactive power demand and its supply. To minimize this gap between reactive power generation and its demand, a variable source of reactive power such as static VAR compensator (SVC) is used. The SG is equipped with IEEE type-I excitation system and dual input power system stabilizer (PSS) like IEEE-PSS3B. The performance analysis of a Takagi–Sugeno fuzzy logic (TSFL)-based controller for the studied isolated hybrid power system model is also carried out which tracks the degree of reactive power compensation for any sort of input perturbation in real-time. In time-domain simulation of the investigated power system model, the proposed SOA–TSFL yields on-line, off-nominal coordinated optimal SVC and PSS parameters resulting in on-line optimal reactive power control and terminal voltage response. The performance of the proposed controller, with the influence of signal transmission delay, has also been investigated.
38 citations