The purpose of this study is to model an operational wind farm in DIgSILENT PowerFactory® using manufactures specifications and investigate the active power energy losses. The model is tested with the operational recorded data from the wind farm and is validated. Meeting the increased demand for renewably generated electricity drives the growth in wind energy which in turn gradually decrease the suitable locations to construct wind farms. On the other hand, the market forces persuade the wind farm developers to maximize the return on investments. Therefore, it is imperative to have optimized wind farm designs as well as accurate financial prognosis. Accurate models are important to estimate the wind farm characteristics while realistic loss estimations are needed for precise financial forecasting. One of the major components of the wind farm is the internal collector network through which the generated electricity is fed to the national electricity grid. With this study, modeling of internal collector network of an operational wind farm is carried out and the capability of the wind farm to maintain the stipulated voltage levels at the point of common coupling is examined together with the amount of cable loading. In addition, the active power energy losses, the impact of the internal collector network arrangement to the active power energy losses are investigated and a proposal to reduce the cost of cable laying for 4 cable sections is proposed for future wind farm designs. The findings of this report show that the internal collector network of the considered wind farm can maintain required voltage levels at the medium voltage busses of the network for different grid voltage levels. The operational data of power loss of the cables of the network match with the simulated results but the total loss does not. The reasons behind this mismatch could be the limited amount of operational data and measurement errors. Further analysis and comparison are suggested with larger sets of data together with the respective list of events to increase number of data points for the simulation.

This research presents a Hybrid Particle Swarm Optimization with Bat Algorithm (HPSOBA) based approach to solve Optimal Reactive Power Dispatch (ORPD) problem. The primary objective of this project is minimization of the active power transmission losses by optimally setting the control variables within their limits and at the same time making sure that the equality and inequality constraints are not violated. Particle Swarm Optimization (PSO) and Bat Algorithm (BA) algorithms which are nature-inspired algorithms have become potential options to solving very difficult optimization problems like ORPD. Although PSO requires high computational time, it converges quickly; while BA requires less computational time and has the ability of switching automatically from exploration to exploitation when the optimality is imminent. This research integrated the respective advantages of PSO and BA algorithms to form a hybrid tool denoted as HPSOBA algorithm. HPSOBA combines the fast convergence ability of PSO with the less computation time ability of BA algorithm to get a better optimal solution by incorporating the BA’s frequency into the PSO velocity equation in order to control the pace. The HPSOBA, PSO and BA algorithms were implemented using MATLAB programming language and tested on three (3) benchmark test functions (Griewank, Rastrigin and Schwefel) and on IEEE 30- and 118-bus test systems to solve for ORPD without DG unit. A modified IEEE 30-bus test system was further used to validate the proposed hybrid algorithm to solve for optimal placement of DG unit for active power transmission line loss minimization. By comparison, HPSOBA algorithm results proved to be superior to those of the PSO and BA methods. In order to check if there will be a further improvement on the performance of the HPSOBA, the HPSOBA was further modified by embedding three new modifications to form a modified Hybrid approach denoted as MHPSOBA. This MHPSOBA was validated using IEEE 30-bus test system to solve ORPD problem and the results show that the HPSOBA algorithm outperforms the modified version (MHPSOBA). / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)