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Voltage Regulators (voltage + regulator)

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Selected Abstracts

Effects of intermediate load on damping of synchronous generator

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2006
P. Aree
Abstract The transfer-function block-diagram model of a single-machine infinite-bus power system, originally developed by Heffron and Phillips, has been a popular analytical tool amongst power system engineers for explanation and assessment of synchronous generator dynamic behaviors. Since this model simply accounts for the generator field circuit with none of the damper circuits, it may not always give a realistic transient response. Moreover, the model considers only a grid-system load without local and intermediate loads. Hence, effects of these loads together with the damper circuits on electromechanical damping have not yet been completely studied. In this paper, the Heffron-Phillips's model has been advanced to incorporate an intermediate load plus one additional damper circuit in the q -axis. The upgraded model demonstrates a great influence of the intermediate load together with the q -axis damper circuit on the electromechanical damping and the dynamic interaction between the field and damper flux linkages. The study shows the key contributions of load to rise and fall of the damping. It appears that the electromechanical damping can be improved with regard to the unity power-factor load through increasing in the natural damping and decreasing in the automatic voltage regulator (AVR) negative damping torques. Nevertheless, the damping is mostly declined, when the load power factor is poor. Moreover, it is markedly changed in relation to various locations of load. The damping characteristics of synchronous generator are investigated using the eigenvalue and frequency response methods. Copyright © 2006 John Wiley & Sons, Ltd. [source]

A study on a new AVR parameter tuning concept using on-line measured data with the real-time simulator

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2006
Joong-Moon Kim
Abstract Automatic voltage regulator (AVR) parameter tuning for voltage control of power system generators has generally been performed with the analytic methods and the simulation methods, which mostly depend on off-line linear mathematical models of power system. However, due to the nonlinear nature of power system, the mathematical models of the excitation system may not be correct. So the excitation control system performances with the parameter set that is tuned by using the mathematical model, may not be appropriate for some operating conditions. This paper presents an AVR parameter tuning method using on-line measured data of the excitation control system with parameter optimization technique. As this method utilizes on-line operating data, it can overcome the limitation of model uncertainty problems of conventional method. To validate the proposed tuning concept, a scaled model excitation system is connected to the real-time power system simulator, and the proposed tuning concept is tested. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Optimal allocation of distributed generation and reactive sources considering tap positions of voltage regulators as control variables

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2007
Mohamad Esmail Hamedani Golshan
Abstract In this paper, by defining and solving an optimization problem, amount of distributed generators (DGs) and reactive power sources (RSs) in selected buses of a distribution system are computed to make up a given total of distributed generation for minimizing losses, line loadings, and total required reactive power capacity. The formulated problem is a combinatorial problem, therefore Tabu search algorithm is applied for solving the optimization problem. Results of solving the optimization problem for a radial 33-bus distribution system and a meshed 6-bus system are presented. When using less amount of reactive capacity, regarding tap positions of voltage regulators as control variables has considerable role in loss reduction and improvement of voltage profile. In the case of meshed systems, including line loadings in the cost function can significantly change results of solving the optimization problem such as amount of the required reactive capacity and how to assign DGs and RSs to the selected buses. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Electrothermal compact model of CoolSET voltage regulators for SPICE

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 4 2007
Krzysztof Górecki
Abstract This paper concerns the problem of modelling CoolSET voltage regulators with self-heating taken into account. The limits of the model of this class of regulators developed by Infineon Technologies AG were analysed. A new electrothermal model of CoolSET regulators designed to analyse transient in the SPICE software was proposed. The correctness of the elaborated model was verified on the example of boost and flyback converters. A good agreement of the measurement and calculation results carried out with the use of a new model was achieved. Copyright © 2007 John Wiley & Sons, Ltd. [source]