DC distribution system for energy efficient buildings
01 Dec 2014-pp 1-6
TL;DR: In this article, two case studies have been described where the building is based on the AC distribution system (ACDS) and supplied by public utility including PV and battery bank, and the building was based on DC Distribution System (DCDS) equipped by solar photovoltaic (PV), battery bank and public utility.
Abstract: In the present scenario, electronic load is continuously increasing in the buildings which needs Direct Current (DC) input. These loads require conversion from AC to DC power. On the other hand the Renewable Energy Sources (RES) such as Solar Photovoltaic (PV) produce DC power which has to be converted into AC to tie into electric power systems and again converted into DC for DC compatible loads. These AC-DC and DC-AC-DC conversion stages introduce the energy losses. The DCDS eliminates the conversion stages. It can also decrease the power losses to an acceptable extent. In this paper two case studies have been described 1) the building is based on the AC Distribution System (ACDS) and supplied by public utility including PV and battery bank, 2) The building is based on DC Distribution System (DCDS) equipped by PV and battery bank including public utility. Results have been simulated in the LABVIEW environment. Outcomes show that the DC distribution system with DC internal technology appliances provide the largest energy saving and reduce the building load.
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TL;DR: In this paper, a distributed local control scheme for dc microgrid is proposed along with the basic droop control, where the line resistances cannot be neglected and a centralized controller in each area is used to make the tie-line power flow zero at steady state.
Abstract: In this paper, a distributed local control scheme for dc microgrid is proposed along with the basic droop control. It eliminates the limitations of droop control when the distributed generators are geographically distributed, for which, the line resistances cannot be neglected. Effects of line inductance and constant power loading (CPL) are investigated by analyzing the voltage tracking transfer function for single source system. Stability of two sources single load microgrid with proposed controller is investigated. Simulated responses are presented for two sources single load microgrid (for the sake of simplicity) to depict the proper load sharing and voltage improvement capability of the proposed control method with the consideration of line resistances. However, this can be extended to multiple-source multiple-load configuration connected to the dc bus. A comparison of the result is presented to show the better performance of the proposed control scheme as compared to the conventional droop control and hierarchical secondary control. The interconnected operation of the microgrid is also investigated to show the applicability of the proposed control in the interconnected mode. A centralized controller in each area is used to make the tie-line power flow zero at steady state.
132 citations
TL;DR: Numerical results reveal that using hybrid AC/DC distribution systems in comparison with commonly used AC ones can lead to reduced total costs in the presence of sensitive loads and also high penetration of DGs.
Abstract: The neoteric AC/DC distribution networks are becoming more practical and cost-effective for several reasons such as high penetration of DC distributed generations (DGs) and also ever-increasing growth of sensitive DC electronic loads. Using these networks eliminates some required conversion stages which result in reduced costs and better power quality and reliability. This paper evaluates the economic efficiency of hybrid AC/DC distribution systems compared with conventional AC ones. For this purpose, a conceptual methodology for AC/DC distribution system planning is developed for making a fair comparison between AC and AC/DC distribution systems costs. The proposed methodology determines the optimal AC/DC distribution substation location and size and AC/DC feeder routing, as well as length and capacity of AC/DC feeders in both low-voltage and medium-voltage sides. The cost function comprises of investment and operational costs, including costs of construction, reliability, and loss. The proposed AC/DC planning approach is implemented in a region with no pre-assigned distribution system in different cases, and results are compared in both AC and AC/DC planning scenarios. Numerical results reveal that using hybrid AC/DC distribution systems in comparison with commonly used AC ones can lead to reduced total costs in the presence of sensitive loads and also high penetration of DGs.
43 citations
01 Jan 2015
TL;DR: In this article, the proportional-integral-derivative and fuzzy logic PID (FL-PID) controllers have been designed and compared in terms of performance and performance measures like maximum overshoot and settling time of FL-Pid compared with the PID proved that the former is better controller.
Abstract: DC microgrids are desired to provide the electricity for the remote areas which are far from the main grid. The microgrid creates the open horizontal environment to interconnect the distributed generation especially photovoltaic (PV). The stochastic nature of the PV output power introduces the large fluctuations of the power and voltage in the microgrid and forced to introduce the controller for voltage stability. There are many control strategies to control the voltage of a DC microgrid in the literature. In this paper the proportional-integral-derivative (PID) and fuzzy logic PID (FL-PID) controller has been designed and compared in term of performance. Performance measures like maximum overshoot and settling time of FL-PID compared with the PID proved that the former is better controller. The controllers are designed and simulated in the MATLAB programming environment. The controllers has been tested for the real time data obtained from Pecan Street Project, University of Texas at Austin USA.
30 citations
Cites background from "DC distribution system for energy e..."
...The advanced low voltage direct current (LVDC) distribution system is going to be used for the residential and commercial purposes [5-7]....
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DOI•
01 Jan 2014
TL;DR: In this paper, a standard voltage level DCDS is proposed to minimize the system losses, complexity and complexity of the DC-AC converter in order to reduce the energy consumption of buildings.
Abstract: Abstract—The renewable energy sources (RES) such as photovoltaic (PV) are basically DC power sources. In the present scenario, the integration of RES to power distribution infrastructure necessitates the DC-AC converter. Moreover the DC loads in the buildings is ever increasing with the use of CFL, LED, refrigerator, TV, fan, air conditioner, laptop, and other electronics in workplaces and homes. This forced to introduce the internal or external AC-DC converter to tie the DC load to AC distribution infrastructure of existing power system. This is further adding losses and complexity. This AC-DC converter stage can be reduces up to a certain level by DC distribution system (DCDS). Secondly the multi voltage rating of RES and DC load insists to introduce DC-DC converter in DCDS infrastructure. This will further add losses and complexity. In this paper a standard voltage level DCDS is proposed to minimize the system losses, complexity. To verify the simulated results in terms of building load and converter losses, a DCDS equipped with different energy sources like solar panel (PV), public utility (PU) and battery bank (BB) is compared with ACDS.
25 citations
01 May 2017
15 citations
References
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TL;DR: In this article, the authors analyzed available information concerning energy consumption in buildings, and particularly related to HVAC systems, and compared different types of building types and end uses in different countries.
5,288 citations
"DC distribution system for energy e..." refers background in this paper
...The energy consumption in commercial and residential building has been increased 20% and 40% in developed countries [3]....
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TL;DR: In this article, the use of DC power system to supply sensitive electronic loads is treated, and general design issues regarding DC power systems are discussed, and then the measurement results from a scaled laboratory setup are presented.
Abstract: In this paper, the use of DC power system to supply sensitive electronic loads is treated. First, general design issues regarding DC power systems are discussed, and then the measurement results from a scaled laboratory setup are presented. The results show that it is possible to supply sensitive electronic loads through an AC/DC interface, and to keep them online during grid transients. The use of a DC power system to supply sensitive electronic loads will have lower losses compared with a conventional AC uninterruptible power-supply solution due to fewer power conversion steps.
546 citations
TL;DR: In this paper, the authors estimate life-cycle energy savings, carbon emission reduction, and cost-effectiveness of energy efficiency measures in new commercial buildings using an integrated design approach, and estimate the implications from a cost on energy-based carbon emissions.
389 citations
"DC distribution system for energy e..." refers background in this paper
...The estimate lifecycle energy savings, carbon emission reduction, and costeffectiveness of energy efficiency measures in new commercial buildings have been discussed in [9]....
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10 Jun 2004
TL;DR: In this article, sustainability aspects connected to the use of dc for power delivery in low and medium-voltage distribution systems are treated, and the efficiency of an example AC system, a DC system and a mixed AC-DC system are calculated and compared.
Abstract: In this paper, sustainability aspects connected to the use of dc for power delivery in low- and medium-voltage distribution systems are treated. The efficiency of an example AC system, a DC system and a mixed AC-DC system are calculated and compared. It is shown that, under the assumption of a substantial reduction in semiconductor losses, the total system losses decrease using DC. This means that for the same energy delivered, less energy must be produced from the available sources, thereby indirectly reducing the environmental impact of energy production. Moreover, the DC system seems to lead to better utilization of the HV/MV transformer, so that the same system can be expanded to supply a higher load without changing the transformer.
205 citations
"DC distribution system for energy e..." refers background in this paper
...The RES can also help to come over the peak demand and shortage of electricity, especially in India as well as in the world [1]....
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TL;DR: The role of photovoltaic systems in the USA, their operating principles and developments for the future are discussed in this article, where the author discusses the role of PV systems, operating principles, and future developments.
Abstract: Photovoltaics technology is well established as a reliable and economical source of electricity in small, scattered applications, far from urban centers. Now it is looming larger in size and public awareness. The author discusses the role of photovoltaic systems in the USA, their operating principles and developments for the future.
167 citations
"DC distribution system for energy e..." refers background in this paper
...It can be made possible by implementing a DC distribution system (DCDS) [7]....
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...It means if a system is design for 230 volt AC than it can operate at 325 volt DC [7]....
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