fariborz haghighatdar fesharaki

Nowadays, increasing the cost of electrical energy, especially at the peak load duration, besides the environmental caused by fossil fuels, have made the peak shaving problem by clean and renewable energies, one of the important as well as essential subjects in electric power industry. Hence, in this paper, combination of the photovoltaic power plant and the battery storage system is used to solve the peak shaving problem. In doing so, a new formulation is proposed for determining the optimal capacity of the photovoltaic power plant as well as battery storage. In the considered constraints in the mentioned formulation, technical issues and economic problems are combined together in an appropriate manner. Moreover, solving the optimization problem is performed regarding the consumption load profile as well as the hourly cost of the electrical energy of under-consideration costumer, and also the expected value of the inflation and the electrical energy cost in the future years. After that, the obtained solution is evaluated in terms of the economic feasibility and its interaction with the upstream electric power distribution network. Another considerable point in this paper is the use of the real data in an actual network for simulations. The simulation results, confirm the convenient performance as well as good efficiency of the proposed method.

In recent few decades, due to various reasons, including energy crisis and environmental problems, renewable energy sources such as wind energy, solar systems and fuel cells have received much attention. Solar or photovoltaic systems are one of the most widely used renewable energy sources that have a low output voltage. For this reason, research on dc-dc converters has increased in recent years. In this paper, a non-isolated high voltage gain converter with three input-output ports is proposed. This converter provides two separate paths for power flow from each input source to the output load. In order to reduce the number of converter components, some components play multiple roles. Therefore, the energy storage device (battery) will charge with the same components used to transfer the power to the load. In this converter, to increase the voltage gain, the coupled inductor technique is used. Moreover, to reduce the leakage inductance as well as achieving the soft switching condition, two active clamps are used. Since the voltage across the switches is limited, the switches can be used with low voltage stress and thus low conduction losses. In this converter, the ripple of the input current will reduce by adding an inductor at its input. This has a significant impact on the performance and the lifespan of the solar cells. The various operational modes of the converter are discussed and the designing considerations are presented. A prototype of the proposed converter is simulated to supply a 130 W, 330 V load with a switching frequency of 50 kHz, in OrCAD software. Finally, a laboratory sample is implemented and the theoretical analysis are validated by the practical results.

With the development of industry and the demand for electricity, energy supply is economically important with respect to environmental issues. The use of small, distributed products has spread near the subscribers' locations. Determining the location and capacity of products at the distribution network level has a great impact on managing financial resources and improving network parameters. In this paper, the optimal model for determining the location and capacity of distributed generation and static synchronous compensator (STATCOM) is presented, which is economically and technically multi-objective. In the economic part, the reduction of the installation cost of distributed products and STATCOM has been considered, and in the technical part, the reduction of losses and the reduction of the voltage droop of the network bus have been considered. This problem is solved using a genetic algorithm. The simulation results are determined using MATLAB software. The results show the effect of location on voltage reduction

Optimal placement and sizing of equipment in engineering systems is one of the most important and challenging practical problems. Installation of capacitors and distributed generations (DGs) in distribution systems has many benefits, such as improving the reliability as well as reducing the power loss, however, includes high investment costs. Hence, the maximum use of these benefits highly depends on choosing suitable locations for installation. In this paper, the Success Rate Group Search Algorithm (SRGSO) is used for optimal placement and sizing of DG sources and capacitor banks simultaneously in distributed systems. The used objective function includes costs of Expected interruption (ECOST), Energy Not Supplied (ENS), active power losses and DG and capacitor investment, operation and maintenance. To evaluate the effectiveness of the proposed algorithm in finding the optimal solution, various capacitor and DG placement scenarios are simulated on the IEEE 33-bus radial distribution test system. The simulation results show that the proposed method is more effective and has higher capability for solving the problem of capacitor and DG placement, compared to previously proposed methods. Using the proposed method in this paper, the value of active power losses as well as bus voltage profile are improved more than other investigated methods.

In this paper, in order to reduce disturbance attenuation in the single-machine infinite-bus system a STATCOM by an improved robust back-stepping algorithm based on a particle swarm optimization approach is proposed. In the proposed approach, the adaptive back-stepping method is used to construct the storage function to reduce internal and external disturbances. Also, a nonlinear controller with interference rejection feature and update of the nonlinear parameter substitution law are applied simultaneously. In this research, in order to maintain non-linearities feature, the real-time estimation of uncertain parameters, ensure robustness and insensitivity to large disturbances of the STATCOM system, the adaptive back-stepping sliding mode control method is applied in terms of error compensation design. It should be noted that the proposed controller has a large number of design parameters which affect its efficiency and performance. So, here the particle swarm optimization approach is used to determine the design parameters based on the cost function of the integral of the magnitude of the error. Finally, the simulation results are performed by MATLAB software, confirmed the better performance of the proposed optimal back-stepping sliding mode control method compared to traditional adaptive back-stepping in terms of the speed of adaptation and the response of the STATCOM system.

In this thesis in addition to optimal placement of phasor measurement units (PMUs) a new method is proposed for optimal distribution of measurements redundancy. Since the buses having first order redundancy degrade the system observability by missing their measurements, this method is used to reduce the number of these. On the other hand, the proposed method, in spite of the previous methods, is used to enhance the system observability by improving the redundancy order of the other low order redundancy buses without increasing the number of the lower orders. .In addition, by using this method, the optimal PMU placement can be obtained considering the contingencies such as PMU outage or line outage. It should be noted that the proposed methods are implemented on the IEEE 14-, 30, 57- and 118- bus power networks. The simulation results are compared with previous methods. In addition, simulations are performed with and without considering the effect of zero injection buses.

Incremental increasing use of the electrical energy and restructuring the power networks and the problems that they have been brought with them, cause increased the power operator’s interest to use of WAMS instead of SCADA. One of the main issues in the WAMS is the cost reduction of the optimal placement of PMU and correlated communication infrastructure. In this paper, a new method is presented for WAMS designing, with the aim of cost reduction. For this purpose, the greedy algorithm is used for optimal placement of PMUs and simultaneously, with the use of the Bellman-Ford algorithm, minimum communication infrastructure is designed so that the total cost of WAMS designing is reduced. Also the optimum location of the PDC is determined with the Bellman-Ford algorithm. This method is proposed in the normal operation condition and also in N-1 contingency conditions ( e.g. a single PMU loss and a single line outage). Simulations are conducted on the IEEE 30- and 118-bus power networks and the 230kv and 400kv of the Isfahan power network. Simulation results show good performance of the proposed method.

Nowadays, the optimal application of phasor measurement units (PMUs) in power systems is increasing because of their advantages such as the capability for dynamical state estimation and improvements in the speed of control and protection systems. In this paper, a new method is presented using binary integer linear programming for the optimal placement of PMUs to guarantee full observability of a power system. Moreover, the problem of the optimal placement of these units in the case of a single line outage is investigated. In all of the investigations, the effect of zero-injection buses in the power system was considered. The ability of the proposed method in solving any of these problems was demonstrated by applying to the 14-, 30-, 39-, 57- and 118-bus IEEE standard systems, 42-bus transmission network of Esfahan Regional Electric and also two very large-scale systems with 2383 and 2746 buses. The simulation results verified the effective and appropriate performance of the proposed method in comparison with other methods.