39 research outputs found
A Field Programmable and Dynamic Configurable Power Electronic Converter Concept
Source at https://www.ieee.org/conferences/xplore-conference-proceedings.html.This paper proposes the concept of a field programmable and configurable power electronic converter
together with a new synthesis method. By considering the converter as a pack of resources, the converter
topology and configuration of inputs and outputs can be programmed in the field through, utilising the
available device resources
Charging technology for small maritime vessels
Foredrag holdt ved konferansen "Arctic Frontiers", Tromsø, 21.-24.1.201
Load modeling from smart meter data using neural network methods
Electricity load modeling plays a critical role to conduct load forecasting or other applications such as non-intrusive load monitoring. For such a reason, this paper investigates a comparison study of two common artificial neural network methods (Multilayer perceptron (MLP) and radial basis function neural network (RBF-NN) for home load modeling application. The accuracy of load modeling using neural network methods highly depends on chosen variables as the input data set for the networks. For this purpose, data including weather, time, and consumer behavior are considered as the input dataset to train the networks. The results of this study show that the RBF-NN model has higher accuracy in training data. On the other side, the MLP model outperforms in test data. To sum up, the results prove that the load model obtained by MLP has a better performance in terms of mean square and root mean square error indices
Deep Adaptive Ensemble Filter for Non-Intrusive Residential Load Monitoring
Identifying flexible loads, such as a heat pump, has an essential role in a home energy management system. In this study, an adaptive ensemble filtering framework integrated with long short-term memory (LSTM) is proposed for identifying flexible loads. The proposed framework, called AEFLSTM, takes advantage of filtering techniques and the representational power of LSTM for load disaggregation by filtering noise from the total power and learning the long-term dependencies of flexible loads. Furthermore, the proposed framework is adaptive and searches ensemble filtering techniques, including discrete wavelet transform, low-pass filter, and seasonality decomposition, to find the best filtering method for disaggregating different flexible loads (e.g., heat pumps). Experimental results are presented for estimating the electricity consumption of a heat pump, a refrigerator, and a dishwasher from the total power of a residential house in British Columbia (a publicly available use case). The results show that AEFLSTM can reduce the loss error (mean absolute error) by 57.4%, 44%, and 55.5% for estimating the power consumption of the heat pump, refrigerator, and dishwasher, respectively, compared to the stand-alone LSTM model. The proposed approach is used for another dataset containing measurements of an electric vehicle to further support the validity of the method. AEFLSTM is able to improve the result for disaggregating an electric vehicle by 22.5%
Thyristor based short circuit current injection in isolated grids
Embargoed Access, IEEEs general regulations (manuscript version for OA after 24 mnths embargo from publication date) Link to publisher's version: http://doi.org/10.1109/ECCE.2016.7855523This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments
A Novel Technique to Mitigate the Overlap-Time Effect in Current Source Inverters
Generally, the current source inverter is considered more reliable than the voltage source inverter due to the presence of inductor as an energy storage element on the DC link, but a disruption in the inductor current could significantly risk its reliability. To guarantee the reliable operation of current source inverter, an overlap time must be added to the gate signals of its switches. This ensures the safe operation of current source inverter but results in increased total harmonic distortion and reduction of DC current utilization ratio. This paper proposes a new technique for reducing the effect of overlap time and improving the performance of pulse width modulated current source inverter. The proposed technique modifies the level-shifted sinusoidal pulse width modulation to mitigate the effect of overlap time. In this paper, the working principle of the proposed technique is presented in detail, and a mathematical relation between the level shifting and overlap time is established. Moreover, a function for the approximation of output AC current is also presented. Finally, results from computer simulations and experiments are presented which validate the effectiveness of the proposed technique
Når blir skipsfarten grønn?
Avisartikkel Fremover 25.4.2018 https://www.fremover.no/debatt/leserbrev/grovfjord/nar-blir-skipsfarten-gronn/o/5-17-401673n av utfordringene i forbindelse med dagens skipsfart er utslipp til luft, hovedsakelig karbondioksid og nitrogenoksider. Disse utslippene er knyttet til oljefyrte forbrenningsmotorer som dominerer dagens skipsflåte. Det er overveiende sannsynlig at det er en direkte sammenheng mellom global oppvarming og utslipp av klimagasser. Utslipp til luft kan også bidra til sur nedbør og svevestøv, for å nevne noe. Disse forurensende petroleumsressursene vil etter hvert armes ut og før eller senere ta slutt