Middle East - North Africa and the millennium development goals : implications for German development cooperation

          Closed-loop controlled combustion is a promising technique to improve the overall performance of internal combustion engines and Diesel engines in particular. In order for this technique to be implemented some form of feedback from the combustion process is required. The feedback signal is processed and from it combustionrelated parameters are computed. These parameters are then fed to a control process which drives a series of outputs (e.g. injection timing in Diesel engines) to control their values. This paper’s focus lies on the processing and computation that is needed on the feedback signal before this is ready to be fed to the control process as well as on the electronics necessary to support it. A number of feedback alternatives are briefly discussed and for one of them, the in-cylinder pressure sensor, the CA50 (crank angle in which the integrated heat release curve reaches its 50% value) and the IMEP (Indicated Mean Effective Pressure) are identified as two potential control variables. The hardware architecture of a system capable of calculating both of them on-line is proposed and necessary feasibility size and speed considerations are made by implementing critical blocks in VHDL targeting a flash-based Actel ProASIC3 automotive-grade FPGA

Advanced Power Controlling Techniques for Dfig – Based Wind Turbines- a Review

As we move forward, a lot of changes in the technological field regarding energy production can be witnessed. Renewable energy sources are penetrating the energy production field mainly due to the numerous advantages they offer in contrast with conventional fuels. Moreover, the finite nature of fossil fuels and the dangers faced regarding climate changing are two more factors contributing to the above. The wind energy is considered as one of the most promising alternative of energy with enormous potential. The main problem during the exploitation of wind power as an energy source is that it is not a constantly available one. Furthermore, the fluctuating nature of wind speed and direction can cause many disturbances in the power delivered to the grid or even cause generator tripping, system decoupling, etc

A Novel Tchnology for Harmonics and Unbalance Compensation in Electric Traction System Using Direct Power Control Method

Power quality problems in power systems have been improved due to nonlinear loads. To compensate these problems Direct Power Compensator was proposed in this paper. A Direct Power Compensator (DPC) is proposed in this paper to eliminate the harmonic currents, compensate power factor and voltage unbalance problems created by the nonlinear loads present in three phase systems. A DPC contains back to back converter by sharing the same dc link power and v/v transformer to provide a voltage balance in transmission line. Hysteresis harmonic current regulator is used to produce pulse for back to back converter. A controller maintains the dc-link voltage and compensates the power factor, harmonic currents. A comparative analysis for traction system with and without DPC was performed using MATLAB Simulink. Simulation results show the controller advantages and the applicability of the proposed method in railway systems

A Combined Vector And Direct Powercontrol For Dfig-based Wind Turbines

Author has proposed, combination of two methods vector and direct power (CVDPC) is implemented, for the rotor side converter (RSC) of doubly fed induction generators (DFIG). The implemented control system is based on a direct current control by selection of appropriate voltage vectors from predefined switching table. Benefits of vector control (VC) are Fast dynamic response, system is robust even there variation in machine parameter, lower mathematical calculation and easy for implementation [1]. If we compare vector control with direct power control (DPC), it offers a advantages like less harmonic distortion and lower ripple count. While carrying out this research author has done simulation based on a Matlab. If we compare with CPDVC with VC and DPC under steady state and transient conditions

Recent Trends InDigital Differential Protection of Power Transformer

Digital protection has several advantages over conventional protection scheme. For protecting costliest and vital equipment such as transformer, digital schemes have been proposed by several authors in recent past. This paper throws light on allsuch efforts and it will help researchers to focus on integrated efforts to protect transformer in a better and efficient way. Artificial intelligence along with signature and pattern recognition techniques give much more useful information about happenings in and outside of transformer. Efforts are put by all concerned with Fast, accurate, flexible, reliable and easy to understand scheme of protection. With the advent of soft computingmethods condition monitoring with protection has become on line objective. Keeping all these state of art techniques of protection, this paper will be a useful resource.Discrimination of several faults external and internal needs digital signal processing and feature extraction as well. Many algorithms are proposedas summarizedin paper