Particle Swarm Optimization Based Reactive Power Dispatch for Power Networks with Distributed Generation

Reactive power is critical to the operation of the power networks on both safety aspects and economic aspects. Unreasonable distribution of the reactive power would severely affect the power quality of the power networks and increases the transmission loss. Currently, the most economical and practical approach to minimizing the real power loss remains using reactive power dispatch method. Reactive power dispatch problem is nonlinear and has both equality constraints and inequality constraints. In this thesis, PSO algorithm and MATPOWER 5.1 toolbox are applied to solve the reactive power dispatch problem. PSO is a global optimization technique that is equipped with excellent searching capability. The biggest advantage of PSO is that the efficiency of PSO is less sensitive to the complexity of the objective function. MATPOWER 5.1 is an open source MATLAB toolbox focusing on solving the power flow problems. The benefit of MATPOWER is that its code can be easily used and modified. The proposed method in this thesis minimizes the real power loss in a practical power system and determines the optimal placement of a new installed DG. IEEE 14 bus system is used to evaluate the performance. Test results show the effectiveness of the proposed method

Coordinated Volt/Var Control in Smart Distribution System with Distributed Generators

The high penetration level of Distributed Generation (DG) is one of the most attractive features of the smart grid aside from being automatic, modern, reliable and efficient. However, high penetration comes with more challenges to deal with such as the voltage and reactive power (Volt/Var) control and increased power loss. To address the issues in incorporating DGs in the power distribution system, this thesis provides a closer look at the Volt/Var control and power loss concerns caused by the random behavior of DGs. Modifying conventional control techniques by moving to a smart technique is a core requirement to mitigate these issues. Voltage control is hard if it is solely handled by on load tap changer (OLTC) transformer and switched shunt capacitors (SC) due to the high penetration and unpredictable behaviors of DGs. The ability to inject the reactive power of the DGs with the proper coordination of SC and OLTC can contribute to control Volt/Var besides minimizing the power loss. Centralized or distributed control of the Volt/Var control device integrated with heuristic based control scheme can be a promising solution to this problem. The distributed control scheme based on the automated agent technology is the first solution to the Volt/Var control problem presented in this thesis. . This is also known as the multi‐agent based system. Each device, i.e. OLTC, DG unit, SC and loads have their own intelligent agents which are capable of optimizing their operations via local measurements and communications with other control agents. Assuming the existence of proper communication medium and protocols, each agent without the knowledge of the whole system, can contribute to control Volt/Var. While doing so, none of the agents are going to violate their own requirements while attaining the global objective of Volt/Var control and reducing total system loss. The proposed control scheme for Volt/Var control is tested and simulated using the 8 bus distribution system in Matlab/Simulink. Fuzzy logic controller for each agent is used based on predefined rules. It was found that the voltage profile is improved after coordinating all the control devices with DGs. The number of tap operations for OLTC is also reduced after the coordination resulting to its increased lifetime. In the second part of this thesis centralized genetic algorithm based control mechanism is introduced in the system. In this section OLTC and SC are treated as controllers and DGs are treated as PQ bus. To get optimum voltage and realize reactive power control, the second part shows 24 hours lead time coordination among the OLTC, SC and DGs. This coordination takes place utilizing genetic algorithm. The optimal number of switching during the 24-hour period for both SCs and OLTCs is determined with the goal to control reactive power flow or minimize the power loss, and above all to keep the voltage profiles within acceptable levels. The functionality of the proposed technique is tested through the simulation of a 30-bus system in Matlab. Findings from the simulation results showed that the DG operation no longer imposes a significant effect on the voltage fluctuations and power loss profile in the distribution system if the OLTC and SC are switched based on a 24-hour forecasted data of the DGs. The adaptive control technique which updates switching time and number every 6 hours of the day gives a better loss profile since the forecasted data becomes more accurate with time. This approach is simple, straightforward and efficient

Evaluation of advanced voltage control algorithms for future smart distribution networks

PhD ThesisThis thesis is composed of two primary parts. The first part, which comprises seventy per cent of this doctoral study, is made up of two new history plays, We’re Gonna Make You Whole and The Interrogation. The second part, which makes up the remaining thirty per cent, is a critical analysis that positions my creative writing within the spectrum of Canadian postcolonial drama, alongside other dramatists who employ magical realism and new historicism in their work. I analyse my creative practice and compare and contrast Marie Clements’s Burning Vision with We’re Gonna Make You Whole. In the final chapters I analyse my way of working, looking closely at the construction of The Interrogation. The creation of the two new history plays is my primary contribution to knowledge. Published in 2011 by Oberon Books, the first of my two submission plays, We’re Gonna Make You Whole, is a magical-real new history of the 2010 Deepwater Horizon Disaster. This compact, two-act play interrupts and disrupts the mainstream mediatised history of the disaster by deploying an interwoven, alternate perspective of the catastrophe. This interruption aims to make the mainstream history seem uncanny by normalising the alternate, subversive history. Set in the military headquarters of an unidentified military body, The Interrogation, my second play, interrupts the mainstream narrative of the global economic crisis by suggesting a link between the neocolonial attitudes of the UK, US and Germany and the present financial landscape. The play dramatises the brutal interrogation of two soldiers, one junior and the other senior, by a mysterious chameleon interrogator (also a soldier) who assumes the accent, affectations and status of his ‘victims’.Northern Powergri