|
| ||
|
|
||
Bus Voltages (bus + voltage)
Selected AbstractsApplication of decentralized control for remote power system stabilization by installing renewable energy power plantIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2008Tomonobu Senjyu Senior Member Abstract The generating power of wind turbines varies in proportion to the cube of wind speed, hence, they cannot supply constant power and this causes fluctuations in frequency and voltage. This article presents a methodology for controlling grid frequency, hydrogen volume, and terminal bus voltage. This system consists of diesel generators, wind turbines, and load. Aqua electrolyzer and fuel cells are introduced in order to control grid frequency, voltage, and hydrogen volume. By applying H, control, frequency, voltage fluctuation, and hydrogen volume, controls are achieved. H, decentralized controllers are designed and installed for diesel generators, aqua electrolyzers, and fuel cells in series. In order to verify the effectiveness of the suggested system, MATLAB/SIMULINK is used for simulation. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Optimal methodology for distribution systems reconfiguration based on OPF and solved by decomposition techniqueEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2010H. M. Khodr Abstract This paper presents a new and efficient methodology for distribution network reconfiguration integrated with optimal power flow (OPF) based on a Benders decomposition approach. The objective minimizes power losses, balancing load among feeders and subject to constraints: capacity limit of branches, minimum and maximum power limits of substations or distributed generators, minimum deviation of bus voltages and radial optimal operation of networks. The Generalized Benders decomposition algorithm is applied to solve the problem. The formulation can be embedded under two stages; the first one is the Master problem and is formulated as a mixed integer non-linear programming problem. This stage determines the radial topology of the distribution network. The second stage is the Slave problem and is formulated as a non-linear programming problem. This stage is used to determine the feasibility of the Master problem solution by means of an OPF and provides information to formulate the linear Benders cuts that connect both problems. The model is programmed in GAMS. The effectiveness of the proposal is demonstrated through two examples extracted from the literature. Copyright © 2009 John Wiley & Sons, Ltd. [source] Linear-programming-based method for optimum schedule of reactive power sources in integrated AC-DC power systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 1 2003M. Abdel-Salam This paper is aimed at obtaining the optimal flow of reactive power which corresponds to minimum real power losses in integrated AC-DC power systems including one DC link. The DC power or DC current, drawn by the link at its rectifier side is introduced as a new control variable added to the normal control variables, i.e. transformer tap-settings, generator terminal voltages and reactive-power outputs, and switchable reactive power sources. The constraints include the reactive power limits of the generators, limits on the load bus voltages and the operating limits of the control variables. Dual linear programming is applied to minimize an objective function for system losses. Application of the proposed method on different test AC-DC systems confirmed that less system losses is achieved with the introduction of the DC control variable. [source] High power factor ac/dc/ac converter with h-bridge cascade five-level pwm inverterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2001B.-R. Lin This paper presents an AC/DC/AC converter which consists of a three-phase switch-mode rectifier (SMR) and a three-phase multilevel inverter with separate isolated DC power supplies. Based on a hysteresis current control scheme in the stationary reference frame, the three-phase SMR is controlled to supply sinusoidal currents with high power factor and low current distortion. The separate DC bus voltages are provided by regulated switch-mode DC/DC converters. The series connection of H-bridge cells is adopted to provide multilevel phase voltage. The control scheme of the three-phase multilevel inverter is based on a look-up table with sine-triangular pulse-width-modulation (PWM) method. The voltage unbalance problem between the separate isolated DC bus voltages is improved by using the proposed control scheme. The proposed control algorithm of the AC/DC/AC converter is verified by simulation and experimental results. [source] | ||||||||||