الفهرس | Only 14 pages are availabe for public view |
Abstract Penetration of renewable energy sources (RESs) such as PV and wind energies in electrical distribution systems has many technical and environmental advantages. But in the other side the uncertainty nature of these sources is considered as one of the most troubling problems which effect on the distribution systems. The uncertainty output problem of the RES returns to its dependency on the climatic conditions which are continuously varying. Varying the output of RES can cause voltage variation for the distribution system which has a destructive effect on the system components and loads. In this thesis, a proposed method is presented to solve the voltage variation problem. In this line, a generalized backward-forward sweep load flow method is developed to analyze balanced and unbalanced distribution systems, also uncertainty models are presented to represent the uncertainty output of both PV and wind systems. Reduction of RESs uncertainty impact is employed through bi-stage method. The 1st stage depends on voltage-regulating devices such as voltage regulators, transformer tap changers, and D-FACTS to control the system voltage. The optimal placement and setting of the voltage regulating devices is considered as an optimization problem which can be solved by optimization algorithms. There are many optimization algorithms such as deterministic and heuristic algorithms. To test the effectiveness of the proposed algorithm, a comparative optimization study is carried out between the proposed cat swarm optimization algorithm and other well-known algorithms to get the optimal placement and sizing of the distributed generation units in different distribution systems. The results show the effectiveness of the proposed algorithm compared to other algorithms. In addition, the 2nd stage is dependent on adding a dispatchable distributed generation (DDG) accomplished with the voltage regulating devices and determining their sizes and locations using the proposed method. The proposed method is presented to obtain the optimal scheduling of voltage regulating and DDG devices to achieve the lowest uncertainty influence on the voltage fluctuations, keep the system voltages within the allowable limits and enhance the system performance. The proposed method is applied to a real unbalanced IEEE 34-bus standard distribution test system. Satisfactory results using the proposed method are obtained compared to other methods. |