A Single-Inductor Multiple Current Output RGB LED Driver Architecture with Hybrid Dimming for Large-Scale Facilities

2021 ◽  
Author(s):  
Joao Dinis ◽  
Fernando Bento ◽  
Antonio J. Marques Cardoso
Keyword(s):  
Large Scale ◽  
Led Driver ◽  
Current Output

Development of Composite Indicators of Cyclical Response in Business Surveys

2021 ◽  
Vol 28 (2) ◽  
pp. 24-41
Author(s):  
L. A. Kitrar ◽  
T. M. Lipkind
Keyword(s):  
Large Scale ◽  
Integrated Approach ◽  
Early Response ◽  
Business Environment ◽  
Economic Behavior ◽  
Retail Trade ◽  
Composite Indicators ◽  
Business Activity ◽  
Short Term ◽  
Current Output

The article proposes a new set of composite indicators-predictors in business tendency surveys, which allow identifying early information signals of a cyclical nature in the economic behavior of business agents. The main criterion for the efficiency of such indicators is their sensitivity to a cyclical pattern and changes in the dynamics of statistical referents. Property such as a statistically significant lead in time series or earlier publication allows them to be combined into indicators of early response. The composite Business Activity Indicator (BAI) in the basic sectors of the Russian economy is calculated by the authors for the first time based on the results of regular (monthly and quarterly) business surveys of Rosstat for 1998–2020 with a large-scale coverage of sampling units. In 2020, the number of survey respondents averaged about 20,000 organizations of all sizes. The index reflects the «common» profile in the dynamics of short-term fluctuations of the key parameters of the economic environment, which consists of the «balances of opinions» of respondents to the questions unified for all sectoral surveys and connected with the reference quantitative statistics with cross-correlation coefficients that are statistically significantly different from zero, with a lead at least one quarter. This is its main difference from the well-known indices of economic sentiment and entrepreneurial confidence. The main components of the BAI are the new composite indices of real demand, current output, real employment, total profits and economic situation. They aggregate the relevant «order» statistics for the basic sectors of the national economy, including the main kinds of industrial activities, retail trade, construction, and services.The article provides a methodological substantiation and an extended procedure for identifying the BAI components; their composition is formed for the entire set of retrospective results of business tendency monitoring in Russia. A new Aggregate Economic Vulnerability Indicator with a counterdirectional profile and varying degrees of symmetry of its dynamics relative to the short-term movement of the BAI is being introduced as the main limitation of business activity. Proactive monitoring of emerging vulnerabilities in the business environment is necessary to warn their large-scale accumulation, prevent the risks of economic downturns and ensure the highest possible macroeconomic stability. This integrated approach makes it possible to determine the novelty of the proposed measurements of short-term cyclical fluctuations in economic development.

scholarly journals Integration of Photovoltaic to the Grid Using Hysteresis Current Control

2021 ◽  
Vol 23 (06) ◽  
pp. 1635-1648
Author(s):  
Reetesh Kumar Maurya ◽  
◽  
Dr. Imran ◽  
Keyword(s):  
Power Generation ◽  
Development Strategy ◽  
Large Scale ◽  
Analog Circuit ◽  
Control Method ◽  
Current Control ◽  
Voltage Source ◽  
Control Procedure ◽  
Current Output ◽  
Hysteresis Current Control

This research paper deals with the increasingly urgent energy issues; the world attaches great importance to begin the development of new energy and related technology. At present, large-scale photovoltaic power generation and scale of renewable energy have become parts of development strategy, meanwhile, it is the way to guide the development of the photovoltaic industry. However, because of its own characteristics different from conventional power generation grid-connected PV power station and its security, stability, reliable operation become new challenges that power grid and PV power plant need to face. Grid-connected voltage source inverters are essential for the integration of the distributed energy resources. However, due to the small capacity and intermittent nature of renewable sources, it is extremely difficult to integrate them into the existing grid system. This project has taken an attempt to design a control method for a three-phase grid-connected inverter system for distributed generation applications. The method is hysteresis current control along with PI control. Hysteresis current control is a commonly employed method for power control of VSI. The control procedure is implemented in an analog circuit using Op-amps and other ICs. This controller will generate pulses to fire the inverter in order to control the current output of the inverter. The control method along with the PI controller provides robust current regulation and achieves unity power factor. In addition, in this project development of a controller in D Space is attempted. Simulation and experimental results are provided to demonstrate the effectiveness of the design.

scholarly journals Efficiency of Cassava Production in China: Empirical Analysis of Field Surveys from Six Provinces

2018 ◽  
Vol 8 (8) ◽  
pp. 1356 ◽  
Author(s):  
Hailing Fu ◽  
Yi Qu ◽  
Yi Pan
Keyword(s):  
Technical Efficiency ◽  
Large Scale ◽  
Production Efficiency ◽  
Raw Materials ◽  
Downstream Processing ◽  
Labor Cost ◽  
Raw Material ◽  
Labor Costs ◽  
Current Output ◽  
Cassava Production

Cassava is becoming increasingly important as an industrial raw material in China. However, an insufficient supply of cassava raw materials and the expanding demand for cassava in downstream-processing industries restricts the development of the cassava industry in China. This paper studies how to increase the scale of cassava planting and promoting cassava production efficiency using output-oriented Data Envelopment Analysis (DEA) modeling. Overall Technical Efficiency (OTE), Pure Technical Efficiency (PTE), and Scale Efficiencies (SE) of the cassava-production system in the major cassava production areas of China are calculated using Variable Returns to Scale (VRS). Results reveal that, in addition to the Guangdong province, the OTE of Guangxi, Hainan, Fujian, Yunnan, and Jiangxi is inefficient, with an OTE of less than 1. The largest cassava-planting province, Guangxi, has the lowest SE with 0.551. The PTE of Guangxi is close to the minimum with 0.344. The OTE of Guangxi is also the lowest among the five provinces with 0.190. This study also presents ways to improve production efficiency. Results reveal that Guangxi has a large ratio of transverse adjustment on average. In the Guangxi province, 1.70% of the service cost and 1.72% of the labor cost need to be eliminated to keep the current output scale. Meanwhile, service and labor costs need to be reduced by 3164.85 and 3209.92, respectively, to achieve the best production efficiency. Further industrialization and large-scale cassava cultivation, increased yield, and strengthened cooperation with the Association of South East Asian Nations (ASEAN) and Africa are suggested as policy options to improve the cassava system in China.

A 200-V 98.16%-Efficiency Buck LED Driver Using Integrated Current Control to Improve Current Accuracy for Large-Scale Single-String LED Backlighting Applications

2016 ◽  
Vol 31 (9) ◽  
pp. 6416-6427 ◽  
Author(s):  
Baek-Min Lim ◽  
Young-Hun Ko ◽  
Yeong-Shin Jang ◽  
Ok-Hwan Kwon ◽  
Sok-Kyun Han ◽  
...  
Keyword(s):  
Large Scale ◽  
Current Control ◽  
Led Driver ◽  
Single String ◽  
Current Accuracy

Adjustable Multi-Light Wireless Remote Control System Designed LED Light

2014 ◽  
Vol 543-547 ◽  
pp. 1250-1253
Author(s):  
Hong He ◽  
Feng Ling Zhang ◽  
Zhi Hong Zhang
Keyword(s):  
Remote Control ◽  
Smart Home ◽  
Current Source ◽  
Constant Current ◽  
Led Driver ◽  
Constant Current Source ◽  
Current Output ◽  
The People ◽  
Indoor Wireless ◽  
Lighting Systems

With the development of LED technology, the actual demand of the people for the smart home lighting, this paper designed a multiple lamps for indoor wireless remote control dimmable LED lighting systems. LED driver is using two levels of drive structure, and driver power supply adopts double-road current output, and the size of the output current of each constant current source is flexible to adjust by remote control. Wireless remote control part control multiple lamps by using 4 * 4 keyboard, which realizes intelligent management of LED interior lighting in the smart home.

Design on LED Driver Based on LLC Resonant Topology

2013 ◽  
Vol 303-306 ◽  
pp. 1702-1705
Author(s):  
Jia Min Cui ◽  
Xian Feng Yu ◽  
Wei Jie Xu
Keyword(s):  
Design Process ◽  
Experimental Results ◽  
Constant Current ◽  
Resonant Converter ◽  
Led Driver ◽  
Current Output ◽  
Design Considerations ◽  
Llc Resonant Converter ◽  
Converter Design

As for the DC/DC part in high-effiency LED driver with constant current output, this paper presents the circuit based on LLC resonant topology. The principle of the LLC resonant converter, design process, and the influence of different key parameters to its performance are also prensented. Design considerations and experimental results are presented for a 200W LED driver prototype which demonstrating good performance and the efficiency of the LLC resont converter can be reached above 95%.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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