The fast increase of loads around the world has made electrical networks more and more complex and difficult to operate close to its capacities. This is has led to many problems such as voltage collapse and energy losses. Therefore, flexible alternating current transmission systems (FACTS) are considred as a best solution for solving these problems. Unified Power Flow Controller UPFC is one of the most important and powerful FACTS devices due to its ability to increase the transmission capacity of the power system and reduce the total line losses. The problem of optimizing its number, location and size has become an important requirement for best advantages of this device. In this paper, a proposed relationship to identify the maximum number of FACTS devices that can be installed for a given power network is introduced in the search process code to determine the optimal number, optimal placement and size of UPFC device to enhance voltages profile and reduce overall system losses in the standard IEEE 14 bus test system using genetic algorithm (GA). The obtained results show clearly that all control parameters of UPFCs in each case are within their limits, and whenever the number of UPFCs installed increases, both voltage deviation and total losses well decreases. They also show that the application of the proposed relationship in the search process code facilitates greatly the search for optimal number, optimal placement and size of UPFC devices and reduces the calculation time. On the other hand, the obtained results has been scientifically justified and compared with other works reported in the literature.
In this paper, both standard IEEE test systems 57-bus and Algerian 59-bus are considered. To enhance the power flow of these two considerable networks in terms of voltage profile and reduce the real and reactive total transmission losses, the inclusion of flexible alternating current transmission systems (FACTS) devices is one of the best solutions. For this, a static synchronous compensator (STATCOM) is proposed. Our code is written in the MATLAB computing environment, based on finding the weakest buses in the network, and placing one or two STATCOMs in an appropriate place; in the next step, there would be recalculation of the power flow again. The results of power flow compared with the popular MATPOWER software environment show the exactitude of our code calculation, and the enhancement of voltage profile, especially in buses where STATCOM is placed. Furthermore, the reduction of real and reactive losses shows the effectiveness of the FACTS device proposed.
Micro-grids (μ-grids) are small-scale power grids, specially designed to provide low voltage (LV) power supply to a small number of consumers. These networks include: different production units (energy resources), storage devices and local controllable loads, which have the possibility of being controlled. In this chapter, we will study in detail the constitution of an electrical micro-grid, their two operating modes (connected mode and islanded mode), and their controls. On the other hand, we will also discuss on hybrid micro-grids and their advantages. We will also discuss for the monitoring and data logging products used in micro-grids and hybrid micro-grids. Finally, at the end of this chapter we will ended with the importance of micro-grids systems.
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