/library/oar/handle/123456789/36092 2025-11-05T07:43:36Z /library/oar/handle/123456789/41406 Title: Smart loads based on “electric spring” concept Abstract: The integration of renewable energy sources into the grid has been significantly increasing in recent years. This increase in renewable energy sources is creating new challenges for electrical engineers because power quality problems due to these distributed generation sources are also on the rise. The main power quality problems include over-voltages and under-voltages, frequency fluctuations and also increased harmonics in the electrical grid. This project shall only focus of the voltage fluctuation problems because the variation in active and reactive power being injected into the grid due to the intermittent nature of RES causes variations in the voltage drop along the power line. In literature, one can find several compensators which help mitigate these problems such as STATCOMS, static var compensators and energy storage system. However, each of these has various operational limitations. STATCOMS and static var compensators can only supply reactive power into the grid. On the other hand, the energy storage systems can supply both reactive and active power compensation but are expensive and bulky. Smart loads with electric spring concept (ES) are a new emerging technology which is aimed to help solve power quality problems in the electrical networks. Loads present in electrical networks can be categorised broadly under two main categories: ‘critical loads’ and ‘non-critical loads’. Non-critical are defined as electrical loads that can withstand a range of supply voltage variations without affecting the operation or performance of the same equipment. On the other hand, loads that does not support voltage variations over a wide range are defined as ‘critical loads’. For the latter, regulation of the supply voltage is critical to ensure that the electrical equipment does not sustain any damage during normal operation. There are three types of ES which can be found in literature. The first type uses just a DC-link capacitor as a storage system, the second type uses a battery while in the third type the energy storage is replaced by a bidirectional a.c.-to-d.c. converter. The ES can supply both reactive and active power compensation while reducing the need for distributed energy storage in the electrical network. This project serves as a proof of the concept of the operation of the ES based smart loads in the LV distributed networks. An ES with energy storage was designed, modelled and simulated in Simulink/PLECS in order to verify its effectiveness in maintaining voltage stability across critical loads. The model considers various scenarios in order to verify thoroughly the effectiveness of the considered ES under different operating conditions. From the simulations which were performed, it was concluded that the ES is an effective in regulating the voltage across the critical load even though it has some limitations. Following the simulations of the ES, the hardware interface necessary to implement the ES was also designed and tested. Results are also given of the testing of the circuitry which was implemented during this project. However, the construction of the lab-base prototype was considered to be beyond the scope pf this project. Description: B.ENG (HONS) 2018-01-01T00:00:00Z /library/oar/handle/123456789/41181 Title: MPPT control of a DC/DC converter for a HAWT Abstract: This dissertation shows the application of Maximum Power Point Tracking (MPPT) for a small wind turbine. A laboratory-based setup, consisting of a DC Drive, a PMSG and a designed power converter, was implemented to simulate in hardware the small wind-turbine system. The system was initially simulated in MATLAB Simulink. Following this, the power electronics and control circuits were designed, tested and constructed. Tests were carried out on the PMSG and, eventually, other tests were carried out on the PMSG driven by the DC drive and connected to the constructed power converter. All the testing stages carried out will be explained, and the results obtained will be discussed, various comparisons between those carried out on MATLAB Simulink and in hardware will be made. Description: B.ENG (HONS) 2018-01-01T00:00:00Z /library/oar/handle/123456789/41179 Title: A 1kW drive for an electric bicycle Abstract: This dissertation involves the design, building and testing of a battery pack, power electronic circuitry, and the microcontroller and software based control circuit of a 1kW electric bicycle (e-bike). These drive components were designed to be assembled on, and to replace the components of an existing electric bicycle. The main objectives were to investigate possible design innovations in the current systems utilised in e-bikes and to construct a more flexible and upgradeable system that works to 1kW. The design objective for the battery was to achieve an architecture which allows and facilitates the replacing of individual cells without changing the battery housing, wiring and protection circuitry. This would enable servicing or upgrading the battery by tting more energy dense cells. A further aim was to design a reprogrammable, stand alone micrcocontroller based motor control board for the brushless DC motor (BLDC) used in the bicycle. This board processes inputs from the rider's application of throttle and brakes, and outputs driving signals to the power electronic circuitry. The innovative value for the user would be a control board that can be used with power electronic circuitry of di erent power ratings, and allows for upgrading and modi cation of the bicycle software for di erent uses, such as in quad bikes. The complete drive system was built and tested, and a closed loop current reference control algorithm was implemented in software. The bicycle motor was successfully driven by this control circuitry and the battery pack was tested under load. Description: B.ENG (HONS) 2018-01-01T00:00:00Z /library/oar/handle/123456789/41169 Title: Design of an electric kinetic energy recovery system Abstract: The drive towards reduction of harmful emissions has seen a surge in the development and improvement of electrical implementations and applications in many industries. The car industry, in particular, saw a huge shift towards this segment over recent years with electric cars and hybrids seeing a huge increase in market share. KERS - Kinetic Energy Recovery System is one such development that has been put in use effectively. The two types of KERS being electric and mechanical. The scope of this dissertation was the design, assembly and implementation of an electric KERS applied to a DC motor. This entailed the design of a switch-mode DC-DC converter that involved the use of various components including MOSFETs, gatedrivers, voltage regulators and current sensors. A DC-DC converter converts an input DC voltage to lower/higher output voltages and for the scope of the project it was integrated on the PCB. For the purpose of this project, a full-bridge converter was designed in order that this functioned in four quadrant configuration. Magnitude and angle criterion were used in the mathematical requirements to get to the equation - transfer function of the current controller. Description: B.ENG (HONS) 2018-01-01T00:00:00Z