High-Efficiency Line Conditioners With Enhanced Performance for Operation With Non-Linear Loads

This paper presents the analysis, design, and experimental performance verification of a serial type line conditioner. Since it processes only a fraction of the load power, the overall converter losses tend to be lower and the efficiency of the conditioner higher. Regarding the dynamic performance, the line inductance, which results in a positive zero in the transfer function of the plant, is taken into consideration when designing a voltage controller with higher bandwidth for faster response. In addition, a virtual resistance is included in the control of the system to damp oscillations often seen for operations at light load and with nonlinear load conditions. Experimental results obtained with a 10 kVA prototype of a serial line conditioner fed from the load side and the proposed feedback control scheme are presented to demonstrate the superior performance of the line conditioner

Energy saving through voltage optimisation & non-intrusive load monitoring in domestic house

Energy consumption worldwide in domestic domain accounts for almost one third of the total energy consumption so it is important to reduce energy usage in this sector for energy sustainability. The project aims to investigate two domestic energy saving methodologies in domestic sector, namely voltage optimisation and non-intrusive load monitoring. The first method is to address the issues of unnecessarily extra usage of electrical energy caused by excessively high mains voltage. It is achieved via a voltage optimiser to maintain the voltage at a desired constant level. The second method is to make electrical energy usage information more transparent to consumers and identify the potential energy waste caused by misusing energy of devices. This is to be achieved via the methodology of load disaggregation. The mains voltage delivered to individual houses varies constantly depending on the location of the house, the load condition and other factors. The method of installing voltage optimiser in domestic houses to optimise the voltage and reduce energy consumption started from last decade. Most of the existing voltage optimisers do not have very precise voltage control and there is very limit report on the theoretical analysis of them. Therefore, a power electronic based voltage stabiliser for voltage optimisation in domestic house is proposed in this project and an intensive study of proposed voltage stabiliser is carried out in terms of the topology, mathematical modelling and control strategy design. The simulation and experiment results are also presented to verify the proposed voltage stabiliser in this thesis. The current method adopted for analysing energy saving is via comparing the electricity bill of a house before and after the installation of a voltage optimiser. But it is impossible to ensure that the user behaviour and energy usage pattern are exact same in these two cases. The lack of quantitative analysis on energy saving has become a major obstacle to convince people and promote the voltage optimisation in domestic house. This project investigated a method for estimating the energy saving of installing a voltage optimiser in real time. An energy saving algorithm is presented and implemented. A test rig hosting different types of electric loads is established to verify the robustness of this algorithm. The experiment results demonstrate that the presented algorithm can estimate the energy saving achieved by a voltage optimiser in real time with very high accuracy. Non-intrusive load monitoring is to disaggregate the total electricity consumption into individual appliances based on the voltage and current measurement at premise level. Most of the existing approaches require massive training and pre-known dataset to obtain the disaggregated energy breakdown of a house and there is no well accepted approach to monitor the home appliances operation in real time. The project is to explore a new method by which the operations of individual appliances can be monitored in real-time simultaneously. A new load signature is proposed to describe the features of appliances and an event based algorithm is developed in this project. The algorithm is then implemented onto a test rig with 6 different appliances and 11 working modes. The evaluation results demonstrate that the proposed algorithm is able to monitor the operations of individual appliances and feedback the information in real time