| 1. |
- Nömm, Jakob, et al.
(författare)
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An analysis of voltage quality in a nanogrid during islanded operation
- 2019
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Voltage quality data has been collected in a single house nanogrid during 48 weeks of islanded operation and 54 weeks of grid-connected operation. The voltage quality data contains the voltage total harmonic distortion (THD), odd harmonics 3 to 11 and 15, even harmonics 4 to 8, voltage unbalance, short-term flicker severity (Pst) and long-term flicker severity (Plt) values, and voltage variations at timescales below 10 min. A comparison between islanded and grid-connected operation values was made, were some of the parameters were compared to relevant grid standard limits. It is shown that some parameters exceed the defined limits in the grid-standards during islanded operation. It was also found that the islanded operation has two modes of operation, one in which higher values of the short circuit impedance, individual harmonic impedance, harmonic voltage distortion and voltage unbalance were reached.
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| 2. |
- Nömm, Jakob, et al.
(författare)
-
Energy Flow Based Risk Analysis for Operating A Standalone Solar-Hydrogen Nanogrid in Northern Scandinavia
- 2019
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Ingår i: 2019 Nordic Workshop on Power and Industrial Electronics (NORPIE). - : IEEE. - 9798350331998 ; , s. 65-73
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Konferensbidrag (refereegranskat)abstract
- In this paper, an energy flow model for a standalone nanogrid was used to calculate the needed hydrogen storage for operation in northern Scandinavia where the electricity was produced from solar photovoltaics. A range of different input parameters such as annual energy consumption, solar production, consumption pattern and heating system was used to obtain a range of optimal system design parameters. From this, two average system configurations were created for two heating systems based on the results from simulated solar data with 2-axis solar tracking and no solar tracking. The average value from the results at 30 MWh of annual energy consumption was used since it is the average energy consumption for a household in northern Sweden. The average system configuration was applied for 15 to 40 MWh of annual energy consumption using 3 measured solar production datasets and 37 different consumption patterns to study the risk for depleting the hydrogen storage and counter measures to avoid depletion. The results show that energy saving measures must be taken during the winter in order to avoid depletion of the hydrogen energy storage, which in turn avoids a sustained interruption until the spring. It was concluded that if 2-axis solar tracking was used instead of no tracking and a stove was used for heating instead of using a heat pump, the probability for depleting the hydrogen storage reduced by 25% to 47.9% at 30 to 40 MWh of annual energy consumption in the nanogrid.
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