Power system harmonics are always an important issue in power networks as they can cause many negative impacts, such as equipment thermal stress, on installations within power networks. Recently, with the increasing connections of power electronic devices based Renewable Energy Source (RES) and High Voltage Direct Current (HVDC) transmission applications, harmonics in power networks, especially high frequency harmonics (>50th order or 2.5 kHz) are on the rise. Currently, the majority of conventional VTs, such as Wound-type Voltage Transformers (WVT) and Capacitor Voltage Transformers (CVT), are widely installed and used in High Voltage (HV) and Extra High Voltage (EHV) power networks for voltage measurement. Since most of them were mainly designed to measure voltage with the required accuracy at the fundamental frequency (i.e. 50Hz in the UK), they are limited to measuring high frequency harmonics due to the coupling of their internal inductive and capacitive elements. To achieve high frequency harmonic measurements, voltage measurement devices with wide frequency bandwidths are required. Recently, non-conventional VTs, such as optical voltage transducers, are commercially available, which could provide accurate voltage measurements over a wide range of frequency. However, before they can be considered by any power utilities, their frequency response performances must be tested at a rated fundamental voltage with required minimum harmonic injections from 100Hz to 5 kHz. This must require a test system which should be capable of providing a rated fundamental voltage up to 400kV with controllable harmonic injections at required levels from 100Hz to 5 kHz. Therefore, the objective of this project is to design and implement such a test system in the National Grid (NG) HV laboratory at the University of Manchester. However, the design and the implementation of such a test system bring many challenges; for instance, a lack of adequate equipment and considerable power to provide the required harmonic injections above 0.5% to the test object.In this thesis, an Instrument Voltage Transformer Frequency Response (VTFR) test system with three different voltage power source designs is presented; The voltage power source designs are: (i) Design 1 is based on a single power source inductive coupling method to provide both a rated fundamental voltage and controllable harmonics; (ii) Design 2 is based on two separate voltage power sources inductive coupling method to provide both a rated fundamental voltage and controllable harmonics; and (iii) Design 3 is based on two separate voltage power sources capacitive coupling method to provide both the rated fundamental voltage and controllable harmonics. A hybrid approach, which combines the VTFR test system with both the voltage power sources Design 2 and 3, is proposed for testing the frequency response of any type of VTs at their rated fundamental voltages with 1% harmonic injections from 100Hz to 5 kHz. The proposed VTFR test system with voltage power source designs were firstly validated at a relatively low voltage of 33kV in the HV laboratory. Then three different VTFR test systems were constructed based on available equipment for testing VTs from 11kV to 400kV. An 11kV, a 33kV WVT and a 400kV WVT and a 275kV CVT were tested. The test results were analyzed, compared and discussed. The models of the test systems were also established and simulated. Simulation results were analysed, compared and discussed.

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To safely transport and use energetic materials, it is important that their response to mechanical excitation at various temperatures be well understood. In order to better understand the thermomechanical response of these materials, samples of inert and live PBXN-109 are fabricated and excited between 10-20 kHz. The resonance of the system is found using a Laser Doppler Vibrometer and the temperature at the surface of the sample is measured with an infrared camera. Samples are loaded into an environmental chamber and tested at -10, 22, 55, and 120 ˚C. Using multiple procedures, the shift in resonant frequency caused by changing material properties can be predicted and followed to elicit the greatest thermal response. Twelve samples are excited using a fluctuating sinusoidal input at each temperature range. The samples are shown to generate significantly less heat from mechanical excitation as ambient temperature increases. Heating rates are also severely affected by temperature. Samples tested at 120 ˚C heat at a rate of ~0.5 ˚C/min, while samples at -10 ˚C heat at ~ 5.7 ˚C/min. Despite the large difference in heating rates samples tested at higher ambient temperatures reached higher peak temperatures. This indicates that the strong temperature dependence of the material properties is likely key to reducing heating caused by mechanical excitation. It also indicates that proper control of ambient temperature should be considered when transporting or using munition systems to ensure safety and proper functionality.

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This dissertation is a study of the composition dynamics of multicomponent distillation in a plate column. A ten-plate bubble-cap distillation column 21 feet in length with a two-foot inside diameter and a one-foot plate spacing was used. There were 22 two-inch bubble caps per plate. The feed system consisted of benzene, n-heptane, toluene, and xylene. Three experimental tests were analyzed; (1) a steady state test in which there was no forcing of the feed stream composition, (2) a transient test in which the feed stream benzene concentration was increased for a twenty-minute period, and (3) a pulse test in which the feed stream benzene concentration was increased for a five-minute period. The sampling frequency for the steady state and transient tests was one sample per minute from the.liquid of each of the plates and the feed, bottoms, and reflux streams. The sampling frequency for the pulse test was one sample every thirty seconds from the liquid and vapor of each plate and from the three terminal streams. The dynamic periods of the transient and pulse tests were simulated by means of a digital computer program. The program was written to solve by a finite difference method the differential equations describing the composition dynamics of the column. The transient and pulse composition response functions were transformed into the frequency domain by means of numerical methods. Simple lumped parameter transfer functions were then fit to the frequency response plots derived from the experimental data. It was determined that the digital computer program used to simulate the composition variations gave satisfactory results in comparison with the experimental data. The method of determining the initial conditions of the dynamic simulation program by means of a steady state multicomponent distillation computer program proved to be satisfactory. / Ph. D.

The objective of this research work was to develop a design tool to analyze and design undamped beam and rotor systems in two dimensions. Systems modeled in two dimensions, such as beams with different moments of inertia, could produce varying responses in the each direction of motion. A coupling between the vertical and horizontal motions also exists in rotor systems mounted of fluid film bearings. The computer program called 2DBEAM has been developed to model and provide analyses of such systems in two dimensions. The tool has been based on an existing design package, BEAM9, which in its present state provides the response of beams and rotors in one plane of motion. The 2DBEAM program has the capability of performing the static response, free vibration, forced dynamic response, and frequency response analyses of a system. The Transfer Matrix Method has been used in the development of the software and an explanation of the method is included in this thesis. Mathematical problems and solutions encountered while developing 2DBEAM are also documented in this study. The code has been tested against analytical and published solutions for the types of analysis mentioned above and on coupled and uncoupled system models. / Master of Science