2,407,721 research outputs found
Fuzzy Inference System for VOLT/VAR control in distribution substations in isolated power systems
This paper presents a fuzzy inference system for voltage/reactive power
control in distribution substations. The purpose is go forward to automation
distribution and its implementation in isolated power systems where control
capabilities are limited and it is common using the same applications as in
continental power systems. This means that lot of functionalities do not apply
and computational burden generates high response times. A fuzzy controller,
with logic guidelines embedded based upon heuristic rules resulting from
operators at dispatch control center past experience, has been designed.
Working as an on-line tool, it has been tested under real conditions and it has
managed the operation during a whole day in a distribution substation. Within
the limits of control capabilities of the system, the controller maintained
successfully an acceptable voltage profile, power factor values over 0,98 and
it has ostensibly improved the performance given by an optimal power flow based
automation system
Kaman 40 kW wind turbine generator - control system dynamics
The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation
Adaptive load frequency control of electrical power systems
The thesis describes Load Frequency Control techniques which may be used for real-time on-line control of large electrical power systems. Traditionally the frequency control of power systems has been carried out using standard fixed parameter control schemes, which give control over the immediate steady- state error and the long term accumulated frequency error, but do not account for the fact that system conditions can alter due to the change in consumer load and generating patterns. The thesis presents a method of controlling the system frequency using adaptive control techniques, which ensure that optimal control action is calculated based on the present system conditions. It enables the system operating point to be monitored so that optimal control may continue to be calculated as the system operating point alters. The proposed method of frequency control can be extended to meet the problems of system interconnection and the control of inter-area power flows. The thesis describes the work carried out at Durham on a fixed parameter control scheme which led to the development of an adaptive control scheme. The controller was validated against a real-time power system simulator with full Energy Management software. Results are also presented from work carried out at the Central Electricity Research Laboratories under the C.A.S.E award scheme. This led to the development of a power system simulator, which along with the controller was validated on-line with the Dispatch Project used by the Central Electricity Generating Board
Optimal Location Of Series-Shunt Facts Devices In Transmission Line And Impact Of SSSC Compensated On Performance Of Distance Relay
The research works says that the impacts of facts devices changes with the change of their location on transmission line. Basically in power system we have two types of compensation devices. First is series facts devices, second is shunt facts devices by using these devices controlling of transmission line voltage and power flow is possible. Facts devices are also very useful to control the reactance power of transmission line and damping of power system oscillation for high power is possible. Series facts devices are connected in series of transmission line and works as a controllable voltage source. Shunt facts devices are connected in shunt with power system line.it works as a controllable current source. During the SLG fault, shunt capacitance of SSSC-compensated line affects the performance of distance relay. Research also shows the impact of ignoring the shunt capacitance of the line on the distance relay over and under reach conditions. By using MATLAB we can study the effects of series and shunt compensation according to the variation of location of these in transmission line. We can find the most suitable and optimal location of series, shunt or the combination of both compensation
Smart grid-Power factor Correction and Maintenance in Consumer Side Using RFID Based Power Line Carrier
Smart grid is a grouping of information and communication technology and intelligent common infrastructure. Talking about smart grid the consumers and suppliers are very much important inorder to manage,monitor and control all energy issuses smartly. Easy instalation and high reliablity data communication over power line carrier is an important requirment to make a smart grid more constructive than fixed grid system.Therefore a latest RFID based power line technology has been developed unlike conventional system carrying data through antenna. RFID based power line carrier technology is used for detection and payment inorder to keep up the grid smart. With this technology, power factor correction and maintanance techniques are included inorder to improve the power system stability. Whenever the non-linear load is connected in load side, the proposed system will automatically detect and connect the power factor correction circuit(capacitor bank) for maintain the power factor in consumer side
Bidirectional Communication System on Power Line Integrated on Electronic Board for Driving of LED and HID Lamps
We present the bidirectional power line communication system developed in parallel to an electronic board for driving and control of HID (high-intensity discharge) and LED (light-emitting diode) lamps. The communication system, developed to be applied in the sector of public illumination, is been designed to combine high efficiency and reliability with low production costs; it consists indeed of discrete cheap components. The communication system described in this paper implements the technique of transporting digital information over existing power lines, avoiding the issue of installing new cables. Digitized signals can use power line cables through the amplitude voltage and current modulation. The solution proposed is more advantageous compared to communication techniques currently on the market which are essentially two types, power line carrier (modem for high-voltage lines) or radio (zig-Bee transceiver)
APPLICATION OF THE POWER LINE SYSTEM FOR TRANSMISSION OF RFAND MICROWAVE SIGNALS
The Power Line System has been used for purposes other than the
transmission of Electrical power, such as low data rate transmission and even AM
broadcast transmission. The broad band over power line (BPL) communication (also
known as the power line communication or PLC) has become the topic of
considerable interest during the last decades. This technology has been proposed for
high data transmission and for a variety of applications including customer Internet
access, emergency communications, and utility grid control. The objective of this
project is to evaluate the use of the power line system in a typical commercial
building for high frequency RF signals (e. g. 100 MHz to 3 GHz) and to develop
simple models of the transmission line to evaluate the effects of the attenuation such
as line loss and radiation in the power line distribution system and also to analyze the
electric and magnetic fields around the lines In order to achieve the objectives of the
project, the simple model of the transmission line would be developed to corroborate
the model measurements to the result obtained and to evaluate the effect of the
attenuation such as line loss and radiation on the transmission line. This will help to
evaluate the communication potential of the system. By the end of the project the
objectives mentioned above has been achieved the electric field around the line has
been analyzed and formulated, the transmission model has been developed and
measurements have been obtained and analyzed. It is found that there is high
attenuation in the BPL system which is frequency dependent as well as background
noises. This significant problems over higher frequencies almost make it impossible
to use this system for communication purposes
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