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Power system quality is a vital issue for electricity companies and consumers of low and medium voltage. So as to decrease the generation power from fossil fuel, it is important to depend on the renewable energy sources which consider as low running cost and low environmental aspects as compared with the traditional power generation. Distributed generation (DG) unit can be defined as a small-scale unit that generates the electric power near the location of customers based on renewable energy sources, including wind energy, solar energy, and geothermal energy. Interconnecting DG with the utility grid can contribute by different advantages to the owner, utility, and the final user. DG gives an improved power quality and higher dependability of the distribution system. In any case, the integration of DG with the existing power system has associated several technical, economic, and regulatory questions. This study discusses the effect of using the DGs with the power system focuses on wind power generation for voltage control and power losses reduction. The simulation analysis in this context has been validated with IEEE-12 Busbars distribution power system as an example to shows the voltage control and power losses reduction. The highlight points from this study to advice and recommends the power system designer to consider the wind DGs with the distribution network for enhancing the power system quality.

Wind generation is considered as one of the optimum renewable energy sources due to its more saving running cost, zero-emission, and friendly environment at comparing with the traditional power plants. Using the wind farms with the utility grid can’t reach the optimum compensation during any abnormal condition in the power system. Distributed Static Synchronous Compensators (D-STATCOM) is a power electronic control system to be used with the distribution power network for harmonics current elimination, reactive power compensation, voltage regulation, voltage flicker mitigation, and frequency regulation. D-STATCOM provides effective compensation to the unbalance or the nonlinear loads by injecting the required accurate value at the Point of Common Coupling (PCC) depending on the Voltage Source Converter (VSC). This chapter proposes a design procedure of a high-power D-STATCOM with the distribution network linked with the wind generation for enhancing the power system quality. The proposed simulation in this chapter has been done using the MATLAB/Simulink software for distribution voltage control, loadability, and power loss reduction using the D-STATCOM control techniques with the electrical distribution network.

Worldwide energy consumption is increasing at a faster pace than energy generation because of enhanced industrialization, growing population and, improved living standards. Using the Distributed Generation (DG) near the end consumers can support the electrical grid stability and enhance the power system quality. The DG is consisting of a small-scale technology to generate electrical power near the end consumers, which can be renewable energy or generators. Solar Photovoltaic (PV) system is considered as one of the best renewable energy sources, due to its low running cost and low environmental affection comparing with traditional power plants. The proposed PVDG units are employing maximum power point tracking (MPPT) system to track the maximum power available in PV arrays. The proposed DG system used Particle Swarm Optimization (PSO) technique to optimally allocate the PVDG units for minimum cost, transmission line losses, and improved voltage profile of busbars under different operating conditions. This paper proposes a smart optimization technique employing PSO in the design, operation, and control of the proposed system. Also, the paper discusses the PSO algorithm for optimal DGs sizing and allocations. The simulation in this paper uses the IEEE-7 busbars system with an extension of IEEE-3 busbars as a new remote load. The simulation has been carried out by the power world simulator software to compare the voltage and the power losses with and without PVDGs connected to the system. The simulation results showed an acceptable reduction in generating cost, transmission line losses, and improvement of the busbars voltage profile which proves the success of the proposed system.

Alteration in cytokine levels, particularly, IL-6, TNF-α, IL-1β and IL-2, has been implicated in the pathogenesis of epilepsy and bipolar disorder. Lamotrigine (LTG), an antiepileptic drug with mood stabilizing properties, has documented immunomodulatory effects. However, its effect on cytokine secretion in vivo has not been examined. Besides, studies have reported inconsistent results of the in vitro effects of LTG on cytokine secretion. Hence, we used murine models of inflammation to characterize the in vivo and the in vitro effects of LTG on the secretion of the aforementioned cytokines, using ELISA. LTG significantly inhibited basal and mitogen-induced IL-6, TNF-α and IL-1β secretion in vivo and in LPS-treated RAW264.7 cells in vitro. In PMs, LTG inhibited basal and LPS-induced IL-6 and TNF-α secretion. Our findings extend the current understanding of the anti-inflammatory properties of LTG and may be relevant to its role in modulating the immune system in epilepsy and bipolar disorder.

Modulation of the immune system has recently been shown to be involved in the pharmacological effects of old antiepileptic drugs and in the pathogenesis of epilepsy. Therefore, the most recent guidelines for immunotoxicological evaluation of drugs were consulted to investigate the immunomodulatory effects of lamotrigine, a newer antiepileptic drug, in BALB/c mice. These included the in vivo effects of lamotrigine on delayed-type hypersensitivity (DTH) response to sheep red blood cell (SRBC) antigens, hemagglutination titer assays and hematological changes. In vitro effects of lamotrigine on ConA-induced splenocyte proliferation and cytokine secretion were assessed. The results showed that lamotrigine treatment significantly increased the DTH response to SRBC in the mouse model of this study. This was accompanied by a significant increase in relative monocyte and neutrophil counts and in spleen cellularity. Lamotrigine significantly inhibited ConA-induced splenocyte proliferation in vitro and it significantly inhibited IL-2 and TNF-α secretion in ConA-stimulated splenocytes. In conclusion, the results demonstrated significant immunomodulatory effects of lamotrigine in BALB/c mice. These data could expand the understanding of lamotrigine-induced adverse reactions and its role in modulating the immune system in epilepsy.

Multiple myeloma is a life-threatening haematological malignancy, which is rarely curable by conventional therapies. Immunotherapy, using tumour antigen-specific, cytotoxic T-lymphocytes, may represent an alternative or additional treatment for multiple myeloma. In this study, we used hybrid cell lines, generated by fusion of an EBV B-lymphoblastoid cell line (B-LCL) and myeloma cells, to stimulate in vitro peripheral blood lymphocytes from patients with multiple myeloma. We investigated induction of antigen-specific, cytotoxic T-lymphocytes to the well-defined tumour associated antigens hTERT, MUC1, MAGE-C1 and CS1, which have been shown to be expressed in a high proportion of cases of multiple myeloma. HLA-A2-peptide pentamer staining, interferon- and perforin ELISpot assays, as well as cytotoxicity assays were used. Following several rounds of in vitro stimulation, the hybrid cell lines induced antigen-specific, cytotoxic T-lymphocytes to four candidate tumour associated antigens in peripheral blood lymphocytes from HLA-A2+ multiple myeloma patients, using known HLA-A2 restricted peptide epitopes of the tumour associated antigens. In contrast, the HLA-A2+ myeloma cell line U266 failed to induce antigen-specific, cytotoxic T-lymphocytes in vitro. Our data indicate that B-LCL / myeloma hybrid cell lines induce antigen-specific, cytotoxic T-lymphocytes in peripheral blood lymphocytes isolated from multiple myeloma patients in vitro and may represent a novel strategy for use in adoptive immunotherapy of multiple myeloma.

Static Var Compensation (SVC) is consists of power electronics circuits to be used with the electric power system for voltage control. SVC is considered as one of the most important and famous modules from the Flexible AC Transmission System (FACTS) devices. SVC is the economic constraints to affect the real network under variation of system operating conditions to maintain the voltage levels and to control the active and reactive power flows. The controlling system by the thyristors into the SVCs modules is more effective to provide fast-acting reactive power compensation. This paper discusses the optimum voltage control techniques using the SVC module with the transmission line to overcome the drop and the influence factors for the voltage in the power system. This paper uses the MATLAB/Simulink software to introduce the thyristors operation steps at coupling the shunt SVC module with the power system to reach the optimal compensation at the voltage drop in the power system. The simulation in this paper has been carried with IEEE-9 busbar distribution system as an example to shows the difference voltage and the power losses without and with SVC installation with the power system.

The purpose of this paper to overcome the impact of electric and magnetic fields on the Intelligent Electronic Devices (IEDs) in High Voltage (HV) substations. The protection devices are considered one from IEDs in HV substation, that's will affect by this fields, this affection will lead to induced current in the secondary connection cables and all devices, that follows to errors in the measurements and the relay decision for the trip command at the fault occurs. So, the calculation of the fault location by the protection IEDs is not accurate. This paper shows the study results of the electric and magnetic field inside HV substation 500 kV, and the result curves shows how the Electromagnetic Field (EMF) vary under HV busbar 500 kV. This study uses the mathematical calculation with MATLAB software, where, the computation domain considered was the 2D free space case study results of a busbar 500kV in outdoor substation design.

This paper discusses the impact of Distributed Generator (DG) on the power system for enhancing the power system quality by improving the voltage profile and power losses reduction. With the increasing on the demand power and the power system extension, the distributed renewable energy technologies are becoming increasingly important in the energy supply systems of many countries. DGs units can be defined as a small-units that generate electric power near to the location of customers based on the renewable energy techniques, including wind energy, solar energy, and geothermal energy. Interconnecting DG to an existing distribution system provides various benefits to several entities as for example the owner, utility and the final user. DG provides an enhanced power quality, higher reliability of the distribution system and can peak shaves and fill valleys. However, the integration of DG into existing networks has associated several technical, economic and regulatory questions. Also, this paper uses the power system IEEE-12 busses for an example to illustrate the voltage control and decreases the active and reactive power losses by adding the wind generation DGs with the distribution network.

This paper presents a load-frequency control (LFC) design using the model predictive control (MPC) technique in a multi-area power system in the presence of wind turbines (WTs). In the studied system, the controller of each local area is designed independently such that the stability of the overall closed-loop system is guaranteed. A frequency response model of the multi-area power system including WTs is introduced, and physical constraints of the governors and turbines are considered. The model was employed in the MPC structures. Digital simulations for a two-area power system are provided to validate the effectiveness of the proposed scheme. The results show that with the proposed MPC technique the overall closed-loop system performance shows robustness in the face of uncertainties due to governor and turbine parameter variation and load disturbances. A performance comparison between the proposed controller with WTs and MPC without WTs and a classical integral control scheme is carried out, confirming the superiority of the proposed MPC technique with WTs. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

This paper aims to develop a method of field orientation scheme for controlling both active and reactive powers of a DFIG (double fed induction generator) driven by a wind turbine. The controlled system consists of a wind turbine that drives a DFIG connected to the utility grid through AC-DC-AC link. The control method is based on the theory of controlling the e d and e q axes components of voltage and current for both rotor side and line side converters using PI controllers. The main control objective is to regulate the dc link voltage for operating at the maximum available wind power. A mathematical dynamic model of a DFIG driven by a wind turbine system is presented. Digital simulation has been carried out in order to evaluate the effectiveness of the proposed system. The results confirm that good steady state and dynamic performances of the proposed system has been achieved under different types of wind speed variations.

This paper aims at developing a method of rotor resistance estimation for speed sensorless indirect vector controlled induction motor drive taking the effect of magnetic flux saturation into account. A mathematical dynamic model of an induction motor as influenced by magnetic circuit saturation is presented. Moreover, a modified structure of indirect vector controller scheme is proposed which involves the saturated value of the magnetizing inductance. In this scheme, an effective online method for rotor resistance estimation is based on a modified model reference adaptive system (MRAS) to achieve high-precise control in a wide range of motor speed. The motor speed is estimated from the difference between the estimated synchronous speed and slip speed. The online magnetizing inductance estimation algorithm to operate within the rotor resistance estimation is presented. Digital simulations have been carried out in order to evaluate the effectiveness of the proposed sensorless drive system. The results have proven excellent steady-state and dynamic performances of the drive system, which confirms validity of the proposed scheme.

This paper proposes the application of H ∞ synthesis to design a robust controller for regulating the volta ge and frequency of a wind generation system. The controlled system consi sts of a wind turbine that drives an induction generator connected to the utility grid through asynchronous AC-DC-AC link. The main control object ive is to regulate the DC link voltage and to track and extract maximu m available wind power. This is accomplished via controlling the fir ing angles of the rectifier and the inverter. The complete nonlinear dynamic model of the system has been described and linearized around an operating point. Also, the design problem of the H ∞ controller has been formulated in a standard form with emphasis on the selection of the weighting functions that reflect robustness and performance goals. The proposed system has the advantages of robustness against model uncertai nties and external disturbances, fast response and the ability to reje ct noise. The performance of the wind generation system with the proposed controller has been tested through a step and sinusoidal chang es in reference input power. In addition, detuned system parameters are a ssumed. Simulation results confirm that good dynamic performance of th e proposed wind energy scheme has been achieved.

This paper investigates the use of the linear quadratic Gaussian controller to control the voltage and frequency of a wind energy conversion scheme. This scheme cosists of a wind turbine and induction generator connected to the utility grid via AC-DC-AC asynchronous link. The control objective aims to regulate the rectifier output voltage and track the maximum available wind power. This is accomplished via controlling the firing angles of the rectifier and the inverter. The complete nonlinear dynamic model of the system has been described and linearized arround an operating point. The standard Kalman filter technique has been employed to estimate the full states of the system. The computational burden has been minimized to a great extent by computing the optimal state feedback gains and the Kalman state space model off-line. The proposed controller has the advantages of robustness, fast response and good performance. The wind energy scheme with the proposed controller has been tested through a step change in wind speed. Simulation results show that accurate tracking performance of the proposed wind energy scheme has been achieved. Moreover, this scheme is robust against the parameters variation and eliminates the influence of modeling and measurement noises.

This paper presents a robust controller design based on Q-parameterization theory for the automatic generation control problem of a power system. This controller is used in order to achieve both robust stability and good dynamic performance against the variation of system parameters. In the Q-parameterization method, the set of all stabilizing controllers of the power system is characterized by a free parameter Q. This free parameter is chosen to satisfy robust stability and other design requirements. Simulation results have confirmed the effectiveness of the proposed controller.

Field orientation, with autonomous control of reactive power, using PI controller is the most widely used controlling method of doubly-fed induction generators (DFIG). This paper describes a method for separate control of active and reactive power of grid-connected DFIG using PI controller. Using MATLAB/SIMULINK software, the behavior of controller is evaluated during variation of wind speed. Simulation results represent the behavior of controller when facing the variations. This paper first explains the model of DFIG and the second part is explaining field oriented control of DFIG.

Enhancement of fault ride-through (FRT) capability and subsequent improvement of rotor speed stability of wind farms equipped with doubly fed induction generator (DFIG) is the objective of this paper. The objective is achieved by employing a novel FRT scheme with suitable control strategy. The proposed FRT scheme, which is connected between the rotor circuit and dc link capacitor in parallel with Rotor Side Converter, consists of an uncontrolled rectifier, two sets of IGBT switches, a diode and an inductor. In this scheme, the input mechanical energy of the wind turbine during grid fault is stored and utilized at the moment of fault clearance, instead of being dissipated in the resistors of the crowbar circuit as in the existing FRT schemes. Consequently, torque balance between the electrical and mechanical quantities is achieved and hence the rotor speed deviation and electromagnetic torque fluctuations are reduced. This results in reduced reactive power requirement and rapid reestablishment of terminal voltage on fault clearance. Furthermore, the stored electromagnetic energy in the inductor is transferred into the dc link capacitor on fault clearance and hence the grid side converter is relieved from charging the dc link capacitor, which is very crucial at this moment, and this converter can be utilized to its full capacity for rapid restoration of terminal voltage and normal operation of DFIG. Extensive simulation study carried out employing MATLAB/SIMULINK software vividly demonstrates the potential capabilities of the proposed scheme in enhancing the performance of DFIG based wind farms to fault ride-through.