Browsing by Author "Chowdhury, SP"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Open Access
    Investigating the effect of solar modelling using different solar irradiation data sets/sources within South Africa
    (2011) Dekker, Justin; Chowdhury, SP; Chowdhury, S
    When designing a solar energy system, accurate solar data for the specific site in which one plans to install the system is required to accurately determine the sizing of the system components based on the available amount of energy. Both the source of the data and the method used for measuring the solar irradiation data are key. This paper specifically deals with the modelling of an off grid photovoltaic power supply system using three different sources of solar irradiation data for two specific geographical locations within South Africa. The paper then goes on to investigate the financial implications in terms of using free solar irradiation data which is available to the public versus accurate ground measured data for a specific site and how it affects the systems component sizing.
  • Thumbnail Image
    Item
    Open Access
    The optimal placement of phasor measurement units and their effects on state estimation
    (2011) Yuill, William; Chowdhury, S; Chowdhury, SP
    Phasor measurement units (PMUs) are a key new technology for use in electric power systems as a backbone for sensing and measurement and to improve interface and decision support using instantaneous PMU data which will drive faster simulations and advanced visualisation tools that will help system operators assess dynamic challenges to system stability. The two main objectives of this work are to investigate and develop 1. a method for the algorithmic placement of a minimum number of PMUs into a system to ensure full observability, 2. conventional, hybrid and linear state estimation techniques to incorporate and utilize PMU measurement data to perform state estimation and to study the effects that differing PMU placement positions have on the accuracy of the resultant state estimator solution.
  • Thumbnail Image
    Item
    Open Access
    Optimal placement of phasor measurement units using the Advanced Matrix Manipulation algorithm
    (2013) Fish, Adbul-Aziz; Chowdhury, S; Chowdhury, SP
    This thesis investigates the problem of the Optimal Placement scheme of Phasor Measurement Units in electrical power systems for State Estimation to facilitate improved monitoring and control of the system parameters. The research work done for this thesis begins with review of Supervisory Control and Data Acquisition systems (SCADA). SCADA-based systems are currently employed for condition monitoring and control of industrial and utility electrical power systems. For utility power networks, the main problem with voltage and current phasor data captured by SCADA systems is that they are not synchronised with respect to each other in a present-time or Real-time framework. This implies that both magnitude and phase angle of the measured phasors tend to get affected by slow data flow provided by SCADA to the points of utilization and also by differences in time instants of data capture. These factors inhibit theefficiency and quality of the power system monitoring and control. “Phasor Measurement Unit” (PMU) is a relatively new technology that, when employed in power networks, offers real-time synchronised measurements of the voltages at buses and currents along the lines that connect them. This is accomplished by using a GPS based monitoring system which facilitates time synchronisation of measurements and unlike SCADA, makes the measured data available in Real-Time format. SCADA is not able to provide Real-time data due to the low speeds at which RTUs (Remote Terminal Units) provide data. Availability of time-stamped phasor measurements makes PMUs preferable for power system monitoring and control applications such as State Estimation, Instability Prediction Analysis, Real-time Monitoring of the system conditions, Islanding Detection, System Restoration and Bad Data Detection.
  • Thumbnail Image
    Item
    Open Access
    Optimal sizing of hybrid renewable energy systems for rural electrification
    (2011) Coppez, Gabrielle; Chowdhury, SP; Chowdhury, S
    This project has the objective of creating a tool for feasibility assessment and recommendations of sizing of hybrid renewable energy systems in rural areas in South Africa. This involves the development of a tool which would analyse information input about the climate of the area and the load demand.
  • Thumbnail Image
    Item
    Open Access
    Stability studies of Sasol Synfuels Transmission and Distribution network under fault conditions and N-1 supply contingency
    (2011) O'Donoghue, Patrick; Chowdhury, SP
    The aim of the work is to perform a transient stability analysis of the Sasol Synfuels Transmission and Distribution network when the power system is subjected to fault conditions and N-1 supply contingency conditions. The work provides an overview of the problem of power system stability as well as discussing issues related to the problem of power system stability; which include power system control and power system modelling.
  • Thumbnail Image
    Item
    Open Access
    Technical and economic analysis of parabolic trough concentrating solar thermal power plant
    (2012) Kariuki, Kibaara Samuel; Chowdhury, S; Chowdhury, SP
    This thesis reports on the technical and economic analysis of wet and dry cooling technologies of parabolic trough CSTP plant. This was done through modelling and simulation of a standalone and grid connected parabolic trough using the System Advisor Model (SAM).