Application Of Facts Devices On Disturbed Power Systems

It is observed that the power factor is maintained closer to unity when the input voltage is reduced from 230V to 110Vrms. Figure 11 (a) and (b) shows the power factor correction of controller for various load condition such as 20% (60W) and 75% (230W). The power factor for the system is found to be 0.84 for light load condition and 0.99 for full load condition. The THD of input current at full load with predominant third and fifth harmonic components are shown in Figure 12(a) and (b).Third harmonics is found to be 4.8% and fifth harmonic component is 4.9% which are well within IEC 61000-3-2 standard during wide range of load variations. The variation in power factor with load is shown graphically in Figure 13(a). It can be inferred from the graph that improved resettable control operates at high power factor for all load condition whereas the conventional PI control has poor power factor under light load conditions. Figure 13(b) shows the comparison between the efficiency of the converter for varying load conditions with the conventional control method and the resettable integrator control. The converter’s efficiency is maintained at 92% for light load conditions and 96% for fully loaded condition with integrator control technique. Thus the improved resettable integrator controller provides a very simple and reliable solution for power factor correction and

“The true method of knowledge is experiment.”- said by a famous English poet William Blake. I, Sakil Ahmed Chowdhury could not agree more with this quote. Thus my ultimate goal to become a prominent researcher in the field of “Power Systems” makes Michigan Technological University my first choice for graduate studies as it provides incredible research prospects to all the students. The presence of copious exceptional faculty members in the field of Electric Power Systems with research interests allied with my own provides an added impulse to apply at MTU.

The power system is installed within 5 electrical substations with emergency equipment, generators, medium voltage panels and transformers.This installation makes the power distribution to Petrobras Headquarters UOBS, which currently controls its offshore operation units (oil platform).The power system is divided into the following subsystems:

The impact of the proposed sequences has been simulated for 0.4 modulation index with a 0.5 lagging power factor load (power factor angle 60°). The simulation setup consists of the following software: 1) MATLAB/Simulink – used to implement the modulation strategies and switching sequences, and 2) PSIM – used to simulate the T-NPC inverter running with an R-L load and to provide conduction and switching losses of each switch. The inverter switching pulses were generated within Simulink and were fed to PSIM through sim-coupler module which provides a link between PSIM and simulink for the purpose of co-simulation [29].

The DVR is one of the most common and effective solutions for protecting critical load against voltage sags [10] [11]. The DVR is a power electronic device used to inject three-phase voltages in series and in synchronism with the distribution feeder voltages in order to compensate for voltage sags. Moreover, it can be efficiently used to augment the fault ride through capability in wind applications. Detection time is an important factor in the voltage restitution process. Fast detection

The characteristic curve of a SPV system varying with solar radiation and temperature does not match the characteristic curve of the load. In those cases, the power conditioning unit regulates the load’s voltage and current in such a way, that the SPV system is operated at its optimum operation voltage (VMPP) and current (IMPP).

While working for Dover Chemical the largest assignment that I was given was to aid a contracting engineer with a power distribution project for the plant. Power distribution is the transfer of energy, or electricity, from one location to another. However In order to understand power transfer from generation to distribution it is important to understand the process from start to finish. AC (Alternating Current) is used for this transfer because of its ability to transmit over longer distance with lower losses by using transformers. Power is lost in transmission lines due to its resistance, the longer the transmission line the higher its resistance will be, however when using polyphase AC current we are able to change the voltage levels through the use of transformers. There are step-up transformers and step-down transformers both are used when transporting power from one location to another.

Introduction: If the system can return to its initial state shortly after it is influenced by temporary disturbances, and it will skip to new state after permanent disturbances, it is called stable system. The security of a power system is the ability to withstand disturbances and maintain stability. Generally, all changes to any one of the parameters can be disturbances. There are a great variety of disturbances as well as the ways to maintain security, but due to limited space this essay will outline some disturbances and focus on a few ways to maintain security. It will discuss how the ways is efficient to withstand disturbances and maintain security.

Power system analysis is important part of power systems. According to the mathematical model we can divide security analysis into two types

Abstract— this paper presents a brief overview of standards for power electronics. All the standards presented in this paper are currently active and are approved by the Institute of Electrical and Electronics Engineer Standards Association (IEEE-SA) and American National Standards Institute (ANSI).

The flexible AC transmission system (FACTS) concepts, based on applying state-of-the-art power electronic technology to existing AC transmission system, improve stability to achieve power transmission close to its thermal limit [4]. Such devices are installed by utilities and by many private entities in India. In order to achieve this identical goal other way is by converting existing 400kV / 765 kV double circuit HVAC line to HVDC line without any modifications in the existing tower structure, insulators and conductors considering heavy pollution as the worst case.

Figs. 8(a-c) show the generated stator, rotor and total active powers respectively. Total active power is identical to the estimated power curve in Fig. 2. Fig. 9 shows the stator reactive power while the rotor reactive power is taken from the DC bus system. The RSC has large size with the lead power factor (Qs= -1.6 MVAR), otherwise, all lag power factors have smaller RSC size.

The development of power electronics devices such as Flexible AC Transmission System (FACTS) and customs power devices have introduced and emerging

• To give the student the basic hands-on experience on the use of industry-based software package to simulate faulted power system.

The controller for the SSSC can be isolated, generally, into two main controllers, namely internal and external controllers. The main function of the internal controller is to give the control signal to drive the gate pattern generator of the power converter keeping in mind to generate a fundamental output voltage waveform with the desired magnitude and phase angle in synchronism with the ac power system. The function of the external controller, if exists, is to alter the reference signals which decides the practical operation of the SSSC so as to accomplish the desired system performance. The block diagram of the SSSC controller is represented in Figure 3.13.