scholarly journals Automatic Measurement for Internal Resistance of Battery in Uninterruptible Power Source

Author(s):  
Mareks Mezitis ◽  
Vladimirs Karevs

Automatic Measurement for Internal Resistance of Battery in Uninterruptible Power SourceThis paper considers the approach to the measurement of internal resistance of the battery in the uninterruptible power sources (UPSs [1]). Advantages of the approach are the measurements in power supplies without switching-off the battery, simplicity in realization of algorithm.The basic expressions of the theory used in the method about internal resistance of the storage battery are considered.The function chart of construction of an analog part of the scheme, and also algorithm of action of the scheme of logic of decision-making are considered.Construction of the tracing generator of load, the important part in realization of the method is stated. The use of the analog machine for processing of the results of measurements and a differential method of measurement with the purpose of increase the accuracy of the method is offered.

2021 ◽  
Vol 13 (8) ◽  
pp. 4404
Author(s):  
Ji Whan Kim ◽  
Yoon Kyung Kim

This study estimated the induced effects of LNG, mega PV (photovoltaic), small PV, onshore wind and offshore wind power, which will be used as major power sources under the Korea’s energy transition policy. The 2015 Input–Output Statistics of Bank of Korea were used to reflect Korea’s economic structure. The MCI (manufacture, construction and installation) and O&M (operation and maintenance) of each power source would have different effects, so in the analysis the MCI and O&M of each power source were distinguished. According to estimation results, the induced-effect coefficients of the MCI are greater than those of the O&M in every power source. The induced production effect coefficient of the MCI is decreased in the order of mega PV > small PV > LNG power > offshore wind > onshore wind. The induced production effect coefficient of the O&M is decreased in the order of mega PV > small PV > onshore wind > offshore wind > LNG thermal. The induced employment coefficient of the MCI is decreased in the order of LNG thermal > mega PV > small PV > onshore wind > offshore wind. PV power and wind power have bigger induced effects and bring economic effects in Korean economy. The carbon neutrality and energy transition policies implemented by Korea have a certain level of induced effects and offset the burden of transition costs even if existing power sources are replaced with environmentally friendly power sources.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Md Al Mahadi Hasan ◽  
Yuanhao Wang ◽  
Chris R. Bowen ◽  
Ya Yang

AbstractThe development of a nation is deeply related to its energy consumption. 2D nanomaterials have become a spotlight for energy harvesting applications from the small-scale of low-power electronics to a large-scale for industry-level applications, such as self-powered sensor devices, environmental monitoring, and large-scale power generation. Scientists from around the world are working to utilize their engrossing properties to overcome the challenges in material selection and fabrication technologies for compact energy scavenging devices to replace batteries and traditional power sources. In this review, the variety of techniques for scavenging energies from sustainable sources such as solar, air, waste heat, and surrounding mechanical forces are discussed that exploit the fascinating properties of 2D nanomaterials. In addition, practical applications of these fabricated power generating devices and their performance as an alternative to conventional power supplies are discussed with the future pertinence to solve the energy problems in various fields and applications.


Author(s):  
Xin Shen ◽  
Hongchun Shu ◽  
Min Cao ◽  
Nan Pan ◽  
Junbin Qian

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.


2017 ◽  
Vol 9 (6) ◽  
pp. 063104 ◽  
Author(s):  
Zhibin Hao ◽  
Wenbin Li ◽  
Jiangming Kan ◽  
Junguo Zhang ◽  
Guozhu Wang

2019 ◽  
Vol 7 (7) ◽  
pp. 230 ◽  
Author(s):  
Gilltae Roh ◽  
Hansung Kim ◽  
Hyeonmin Jeon ◽  
Kyoungkuk Yoon

The need for technological development to reduce the impact of air pollution caused by ships has been strongly emphasized by many authorities, including the International Maritime Organization (IMO). This has encouraged research to develop an electric propulsion system using hydrogen fuel with the aim of reducing emissions from ships. This paper describes the test bed we constructed to compare our electric propulsion system with existing power sources. Our system uses hybrid power and a diesel engine generator with a combined capacity of 180 kW. To utilize scale-down methodology, the linear interpolation method is applied. The proposed hybrid power source consists of a molten carbonate fuel cell (MCFC), a battery, and a diesel generator, the capacities of which are 100 kW, 30 Kw, and 50 kW, respectively. The experiments we conducted on the test bed were based on the outcome of an analysis of the electrical power consumed in each operating mode considering different types of merchant ships employed in practice. The output, fuel consumption, and CO2 emission reduction rates of the hybrid and conventional power sources were compared based on the load scenarios created for each type of ship. The CO2 emissions of the hybrid system was compared with the case of the diesel generator alone operation for each load scenario, with an average of 70%~74%. This analysis confirmed the effectiveness of using a ship with a fuel-cell-based hybrid power source.


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