A new proposal for the design of hybrid AC/DC microgrids toward high power quality
Autor: | Seyed Ghodratolah Seifosadat, Pouria Goharshenasan Khorasani, Mahmood Joorabian |
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Rok vydání: | 2017 |
Předmět: |
Hybrid AC/DC microgrids
power quality series-parallel compensation harmonic compensation reactive power compensation General Computer Science business.industry Computer science 020209 energy 020208 electrical & electronic engineering Electrical engineering 02 engineering and technology Power factor AC power Converters Distribution transformer DC-BUS Harmonics 0202 electrical engineering electronic engineering information engineering Harmonic Microgrid Electrical and Electronic Engineering business |
Zdroj: | Volume: 25, Issue: 5 4033-4049 Turkish Journal of Electrical Engineering and Computer Science |
ISSN: | 1303-6203 1300-0632 |
Popis: | Considering the advantages of DC microgrids, the extension of the conventional AC distribution grid can be implemented using a DC microgrid. This justifies the realization of a hybrid AC/DC microgrid. In the present study, a new global solution is presented to improve the power quality and to fully compensate the reactive power of an AC microgrid using DC bus capacity while introducing a new design for a hybrid AC/DC microgrid. In the new design, back-to-back connections of two series and parallel converters, as well as the presentation of new controllers and simultaneous utilization of an earthing switch, are proposed. The proposed method guarantees the quality of the delivered voltage to consumers and the drawn current from the network according to the IEEE-519 and IEEE-1159 standards under different power quality problems (e.g., interruptions, sags, harmonics, and any variation in voltage/current signals from pure sinusoidal). Through the proposed design of the new hybrid AC/DC microgrid, as a new feature, the operation of the network in islanded mode can be achieved in accordance with power quality standards even in the worst load quality conditions. It should be noted that in common hybrid microgrids in islanded mode, the delivered voltage quality is proportional to the quality of the consumer's load current. Another possibility of the proposed design is the instantaneous VAR compensation of nonlinear and induction loads of consumers to keep the power factor of the distribution transformer close to unit value. Simulation results indicate that there are acceptable levels of compensation for different types of power quality problems. Total harmonic distortions and total demand distortions are below 3% in both the grid-connected and isolated modes of the hybrid AC/DC microgrid. |
Databáze: | OpenAIRE |
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