Solar-DC deployment experience in off-grid and near off-grid homes: Economics, technology and policy analysis
07 Jun 2015-pp 26-31
TL;DR: In this article, an efficient and affordable solar DC solution for powering off-grid homes is presented. But, the proposed solution is not suitable for the use of the generated PV power efficiently.
Abstract: India is a power deficit country and one third of its homes are off grid or near off grid. This paper presents an efficient and affordable Solar DC solution for powering such homes. Though several solutions have emerged in the past for powering these homes, those have been expensive and energy inefficient. These solutions rely on several DC to AC and AC to DC conversions, to feed the widely used AC home loads, thus, wasting a large chunk of the expensive power. The proposed Solar DC solution for off-grid homes (OGH) is developed to use the generated PV power efficiently. With this solution, the panel and battery size is reduced by 2 to 2.5 times and the cost to power a house is reduced to nearly half the cost of the existing solutions. The paper also presents a techno-economic comparison between the proposed OGH solution with some existing solar systems.
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TL;DR: In this article, a classification learner based supervised ML algorithm is proposed for intentional islanding of DERs based on the live data collected from supervisory control and data acquisition (SCADA) system in post disaster situations.
Abstract: Currently, research work is primarily dependent on the collection of large sets of data from systems and making predictions based on the knowledge obtained from the data, which is generally termed as ‘data mining’. These data mining algorithms are of great importance in improving the performance of different applications. In this regard, Machine Learning (ML) algorithms have been demonstrated to be excellent tools to cope with difficult problems. In this paper, a classification learner based supervised ML algorithm is proposed for intentional islanding of DERs based on the live data collected from supervisory control and data acquisition (SCADA) system in post disaster situations. Literature presents various islanding detection techniques and also intentional islanding algorithms to address different problems in AC networks. These algorithms majorly work based on the control of current source or voltage source inverters. On the other hand, a low voltage DC distribution system allowing the removal of inverter is proposed, which is supposed to be more advantageous by reducing losses and is also economical when working with DERs. In this paper, ML based intentional islanding algorithm for DERs based low voltage DC distribution system is proposed by considering the effects of natural disasters. The learner models trained are fine tree, linear SVM, quadratic SVM and Gaussian SVM. The training of fine tree model is achieved with higher accuracy of 99.8%. The main objective of this work is to achieve a faster and accurate decision making. The performance of the ML based intentional islanding algorithm is compared with the earlier proposed artificial intelligence (AI) based intentional islanding algorithms. The AI algorithms proposed earlier are fuzzy inference systems (FIS), artificial neural networks (ANN) and adaptive network based fuzzy inference system (ANFIS). The comparison shows that, the decision making with ML based intentional islanding algorithm is faster and accurate than all other algorithms.
7 citations
17 Dec 2020
TL;DR: In this article, a standalone DC microgrid is considered consisting of a solar PV, a battery energy storage system (BESS) and loads interfaced together to a DC bus, where a controller is designed to achieve the primary objective of maintaining constant DC bus voltage of 48V.
Abstract: Microgrids (MG) are found to be the sound alter-natives for solving challenges posed by the conventional grid and conventional fuel based generation As a paradigm shift Low Voltage DC Microgrids are emerging alternatives in rural electrification As a part of this work, a standalone DC microgrid is considered consisting of a Solar PV, a Battery Energy Storage System (BESS) and loads interfaced together to a DC bus The loads considered here are DC Homes of three categories designed based on the energy consumption levels and socio-economic factors of rural population The PV power suffers the problem of intermittency due to the environmental factors such as insolation, temperature, etc As a part of this work a practical non uniform insolation data of 24 hours collected at IIT Bhubaneswar campus is considered Correspondingly a loading pattern is also designed for all the houses in view of real life energy consumption pattern in rural areas In the context of variable nature in the source and load, a controller is designed to achieve the primary objective of maintaining constant DC bus voltage of 48V Also, a proper energy management is designed to achieve the secondary objective of power balance in the system Corresponding analysis of the system and results are obtained using simulations in MATLAB/SIMULINK platform
6 citations
TL;DR: In this article, a residential DC microgrid in an urban, underserved area that enables the sharing of renewable energy sources (principally solar PV) and energy storage is analyzed.
Abstract: The availability of fossil fuels in the future and the environmental effects such as the carbon footprint of the existing methodologies to produce electricity is an increasing area of concern. In rural areas of under-developed parts of the world, the problem is lack of access to electrification. DC microgrids have become a proven solution to electrification in these areas with demonstrated exceptional quality of power, high reliability, efficiency, and simplified integration between renewable energy sources (principally solar PV) and energy storage. In the United States, a different problem occurs that can be addressed with the same DC microgrid approach that is finding success internationally. In disinvested, underserved communities of with high unemployment and low wages, households contribute a significant portion of their income toward the fixed cost of their electrical utility connection, which by law must be supplied to every household. This paper analyzes a residential DC microgrid in an urban, underserved area that enables the sharing of renewable and stored energy resources between dwellings. The goal of the residential DC microgrid is to drive down to fixed costs of utility-provided electricity to all participants, such that the percentage of utility cost to total household income comes can be made comparable to that of more advantaged communities. A group of renovated dwellings constitute the community which the DC microgrid would serve. The distributed installation of solar panels and battery storage among dwelling locations are optimized based upon varying consumption patterns. Also, consumption patterns during different seasons of the year are considered. Electrical distribution architectures within the dwellings are based upon conventional AC. Each dwelling has a DC interface to the residential microgrid and progressive insertion of DC loads, with associated household DC distribution, is considered.
6 citations
01 Dec 2016
TL;DR: In this paper, an efficient and cost effective DC-DC power converter for notebook computers is proposed, which employs a synchronous rectified step-down DC/DC converter IC BD9611MUV to yield 195V DC from 48V DC input.
Abstract: There has been enough traction in India to standardize 48V DC home / Office wiring for power, an ideal solution for running office devices and energy storages seeking to provide better efficiency and performance In addition, since most renewable sources provide direct current (DC) power and the batteries used for storing power also give DC power, it is easier to integrate these sources into DC power line The 48V DC power is stepped down to lower DC voltages (12–36V) with the help of converters to power the office and storage devices Once 48V DC is primary wiring, one would require converters to power lower voltage appliances like PCs (which take 19V) and laptops and also TVs (some of them take 12V) Besides once in a while one may have to connect some legacy equipment which takes only AC input The objective of this paper is to design an efficient and cost effective DC-DC power converter for notebook computers The converter employs a synchronous rectified step-down DC/DC converter IC BD9611MUV to yield 195V DC from 48V DC input The performance of developed power converter has been investigated under different input conditions and practical results have been reported in this paper Also, this paper shows that existing large AC appliances can be connected to 48V DC line with the help of Microinverter
4 citations
Cites background from "Solar-DC deployment experience in o..."
...Linking the DC power Sources directly with DC loads, notably reduces the power losses and makes it significantly cheaper [3]....
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Dissertation•
15 Feb 2020
TL;DR: In this paper, battery management system (BMS) ini berfungsi untuk meningkatkan arus ying digunakan pada pengisian baterai, alat BMS ini bekerja sebagai charger untuk me-looping energi pada keluaran Baterai.
Abstract: Battery management System (BMS) ini berfungsi untuk meningkatkan arus yang digunakan pada pengisian baterai, alat BMS ini berkerja sebagai charger untuk me-looping energi pada keluaran baterai. Battery management system ini bekerja dengan bantuan dari komponen current booster. BMS ini bekerja saat tegangan baterai berada diatas 11 volt. Dalam penelitian ini digunakan empat sampel beban lampu dengan variasi 25 W, 50 W, 75 W, dan 100 W. Pada saat pengambilan data dilakuan perbandingan antar pembebanan baterai dengan menggunakan BMS dan tanpa BMS. Penggunaan BMS ini dilakuan untuk mengatur stabilitas dari pengisian baterai yang mana pada saat tegangan baterai berada pada tegangan 11,0 Vdc maka peroses pengisian dari BMS akan dihentikan untuk menjaga stabilitas kinerja dari baterai yang digunakan. Dari hasil pembebanan baterai dengan looping dan tanpa looping didapatkan hasil perbedaan waktu yaitu, pembebanan 25 Watt didapatkan selisih waktu selama 3 menit 43 detik, saat pebebanan 50 Watt didapatkan selisih waktu 2 menit 6 detik, kemudian pembebanan 75 Watt didapatkan selisih waktu 1 menit 42 detik, dan untuk pembebanan 100 Watt didapatkan selisih waktu 48 detik. selisih waktu tersebut yang membuat baterai yang dilooping dapat menjaga realtime baterai lebih lama.
4 citations
Additional excerpts
...digunakan untuk men-charge baterai.[2], [3]....
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References
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07 Jun 2015
TL;DR: In this paper, the authors proposed a DC system, which provides a far more energy-efficient alternative using renewable power-source for backup, by eliminating the complex electronics embedded in the inversion process.
Abstract: Lighting, fans and electronic devices form a significant and growing portion of power-load at homes and need power back-up support in case there are frequent power-cuts. A Diesel generator is generally used today in multi-storied buildings to provide this backup. The DC system, proposed in this paper, provides a far more energy-efficient alternative using renewable power-source for backup. It creates a pull for a home to move towards far more energy efficient DC loads. The solution provides a GREEN option to the existing solution. This paper provides a fresh perspective on the problem of eliminating conversion losses for uninterrupted operation of DC appliances. A cost benefit analysis shows that this DC system can reduce costs to the consumer by eliminating the complex electronics embedded in the inversion process. A rough measurement of the conversion losses for commercially available inverters and battery chargers illustrates that gains of 30% to 45% are easily obtainable
19 citations
07 Jun 2015
TL;DR: In this paper, a load management innovation to provide a limited but uninterrupted DC power supply to homes in India is presented, which enables addition of solar power directly to the DC power line and use of battery, without any converter.
Abstract: This paper presents a load-management innovation to provide a limited but uninterrupted DC power supply to homes in India. In a typically power deficient situation, load shedding becomes unavoidable. The duration and areas where load is shed are typically cycled. In worst situation, power outages last for a greater part of the day. To enable every home to get at least a limited amount of power 24×7, an innovative approach that combines use of DC power and load management has been proposed and implemented in several hundred homes in various locations. In order to make best use of limited power, a DC power line and energy efficient DC appliances are introduced and installed at homes. The approach also enables addition of solar power directly to the DC power line and use of battery, without any converter; the power-limit on DC line can thus be overcome. The paper describes the rationale, implementation and user feedback of the approach. Further improvements and plan for future are indicated.
10 citations
"Solar-DC deployment experience in o..." refers background in this paper
...This power is directly fed to the DC loads which are far more energy efficient as compared to the conventional AC loads [2]....
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