Research on a New Rotary Transformer Device

2014 ◽  
Vol 602-605 ◽  
pp. 2627-2631
Author(s):  
Sheng Li Xie ◽  
Jing Fang ◽  
Ying Jun Chang ◽  
Bor Ning

Using the principle of electromagnetic induction, we designed the new rotary transformer device which secondary winding can rotate with the prime mover. The device not only achieves the purpose that provides synchronous generator with AC power of exciting side, but also can eliminate the impact of slip ring and carbon brushes fundamentally on the system. The test results of the prototype also show that the design of the rotary transformer described herein is possible.

2021 ◽  
Vol 9 ◽  
Author(s):  
Tianyi Zhang ◽  
Haifeng Wang

With the continuous growth in the amount of wind power accessed by the AC grid, the impact of the grid connection of wind-power generators with the power system has gradually increased. In this study, the subsynchronous oscillation of a synchronous generator (SG) shaft caused by the integration of direct-drive permanent-magnet synchronous generators (PMSGs) was investigated. The mechanism governing the effect of the connection strength between the PMSG and AC power system on the stability of the generator shaft system was analyzed based on the complex torque coefficient method. When the connection strength between the PMSG and AC power system weakens, the same voltage variation that occurs at the point of common coupling of the PMSG stimulates more intense power fluctuations in the PMSG, and the electrical damping injected by the PMSG into the SG increases considerably. This may cause the oscillation mode dominated by the generator shaft system to move to the right half of the complex plane, thereby reducing the stability of the generator shaft system. In addition, the evaluation process of the influence of the PMSG on the SG shaft system was summarized, and the proposed method can determine the stability of the AC power system after the integration of the PMSG. Finally, the effectiveness of the proposed method was validated via study cases, and conclusions were drawn. This method is expected to serve as a useful tool for the risk assessment of subsynchronous oscillations in wind farms.


2020 ◽  
Vol 22 (6) ◽  
pp. 395-403
Author(s):  
Charlie Urame ◽  
Paul Ratnamahilan Hoole

Hydro-Electricity and Solar Power are environmentally friendly renewable sources of energy that utilize the potential energy from dammed water and the sun respectively to generate electricity. In this paper is reported a new design and implementation of combining solar and hydro-electric power. The turbine and gearbox system used in this design is fabricated from scarp parts of used appliances. The hydro head of the Pico-Hydro plant commissioned was 5m which accumulated a hydraulic potency of the stream of about 5.886kW. The prime mover of the generator consisted of a modified crossflow turbine that is coupled with a gearbox to amplify the rpm of the system. A 500W synchronous generator was driven by the prime mover to generate raw phase shifted AC power. This raw power was rectified with a 25 A full wave rectifier and used in conjunction with 12 V 400 AH deep cycle battery bank system to supply power to a newly furnished double storey house. The generator output through the full wave rectifier is connected to a load controller for optimal charge efficiency. The load controller is connected to the battery bank through a Programmable Logic Controller (PLC). The PLC activates a dummy resistive hot water element when the battery bank is fully charged. The Arduino GSM module monitors the entire process and automatically sends notification via a SIM interface to the system administrator notifying the system administrator of the on/off state of the heating element.


Author(s):  
Larisa Dmitrievna Popovich ◽  
Svetlana Valentinovna Svetlichnaya ◽  
Aleksandr Alekseevich Moiseev

Diabetes – a disease in which the effect of the treatment substantially depends on the patient. Known a study showed that the use of glucometers with the technology of three-color display of test results facilitates self-monitoring of blood sugar and leads to a decrease in glycated hemoglobin (HbAlc). Purpose of the study: to modeling the impact of using of a glucometer with a color-coded display on the clinical outcomes of diabetes mellitus and calculating, the potential economic benefits of reducing the hospitalization rate of patients with diabetes. Material and methods. Based on data from two studies (O. Schnell et al. and M. Baxter et al.) simulation of the reduction in the number of complications with the use of a glucometer with a color indication. In a study by O. Schnell et al. a decrease of HbA1c by 0.69 percent is shown when using the considered type of glucometers, which was the basis of the model. Results. In the model, the use of a glucometer with a color-coded display for type 1 diabetes led to a decrease in the total number of complications by 9.2 thousand over 5 years per a cohort of 40 thousand patients with different initial levels of HbA1c. In a cohort of 40 thousand patients with type 2 diabetes, the simulated number of prevented complications was 1.7 thousand over 5 years. When extrapolating these data to all patients with diabetes included in the federal register of diabetes mellitus (FRD), the number of prevented complications was 55.4 thousand cases for type 1 diabetes and 67.1 thousand cases for type 2 diabetes. The possible economic effect from the use of the device by all patients with a diagnosis of diabetes, which are included in the FRD, estimated at 1.5 billion rubles for a cohort of patients with type 1 diabetes and 5.3 billion rubles for patients with type 2 diabetes. Conclusion. Improving the effectiveness of self-monitoring, which is the result of the use of glucometers with color indicators, can potentially significantly reduce the incidence of complications in diabetes and thereby provide significant economic benefits to society.


2021 ◽  
pp. 135481662110224
Author(s):  
Liang-Ju Wang ◽  
Ming-Hsiang Chen ◽  
Zhandong Yang ◽  
Ching-Hui (Joan) Su

This study proposes and tests two hypotheses concerning the effects of hotel industry operations on air quality based on data of 26 major tourist cities in China from 2002 to 2017. The empirical analyses take two steps. In the first step, panel regression test results reveal that hotel industry operations (measured by hotel sales revenue) significantly raise the value of particulate matter (PM)2.5 (the key indicator of air quality), supporting the first hypothesis that hotel industry operations deteriorate air quality and providing empirical evidence of the adverse impact of the hotel industry on air quality. In the second step, subsample analyses support the second hypothesis that the impact of hotel sales revenue on air quality diminishes over time. The results from the rolling regression tests validate the existence of a diminishing effect of hotel industry operations on air quality.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1895
Author(s):  
Tomasz Kozior ◽  
Czesław Kundera

This research paper reviews the test results involving viscoelastic properties of cellular structure models made with the PolyJet Matrix—PJM additive technology. The designed test specimens were of complex cellular structure and made of three various photo-curable polymer resin types. Materials were selected taking into account the so-called “soft” and “tough” material groups. Compressive stress relaxation tests were conducted in accordance with the recommendations of standard ISO 3384, and the impact of the geometric structure shape and material selection on viscoelastic properties, as well as the most favorable geometric variants of the tested cellular structure models were determined. Mathematica and Origin software was used to conduct a statistical analysis of the test results and determine five-parameter functions approximating relaxation curves. The most favorable rheological was adopted and its mean parameters determined, which enables to match both printed model materials and their geometry in the future, to make a component with a specific rheological response. Furthermore, the test results indicated that there was a possibility of modelling cellular structures within the PJM technology, using support material as well.


2013 ◽  
Vol 41 (6) ◽  
pp. S69 ◽  
Author(s):  
Sue M. Mietzner ◽  
Andrea J. Schaeffer ◽  
Sue M. Mietzner ◽  
Mohamed H. Yassin ◽  
Marilyn M. Wagener ◽  
...  

2017 ◽  
Vol 16 (1) ◽  
pp. 54-84 ◽  
Author(s):  
Magda Kandil ◽  
Muhammad Shahbaz ◽  
Mantu Kumar Mahalik ◽  
Duc Khuong Nguyen

Purpose Using annual data from 1970 to 2013 for China and India, this paper aims to examine the impact of globalization and financial development on economic growth by endogenizing capital and inflation and drawing comparisons between the two fastest growing emerging market economies. Design/methodology/approach In the long run, co-integration test results indicate that financial development increases economic growth in China and India. Findings The results also reveal that globalization accelerates economic growth in India but, surprisingly, impairs economic growth in China, as it increases competition for exports. The results furthermore disclose that acceleration in capitalization and inflation, as a proxy for aggregate demand, are positively linked to economic growth in China and India. Originality/value Causality test results indicate that both financial development and economic growth are interdependent. In contrast, causality runs from higher economic growth to increased globalization in India, while the results do not support long-term causality between globalization and economic growth in China.


Author(s):  
Dorota Brzezinska ◽  
Marcin Fryda

The following technical note demonstrates full-scale staircase test results of the pressure differential system improvement method described by Fryda et al. in 2021. It is a continuation of experimental research on the impact of the escape route’s leakages on the pressure differential systems for staircases. Based on the lab experiments, it has been found that an additional throttle of the leak implemented in the pressure differential system improves its effectiveness and allows it to be more precisely adjusted to the required overpressure. The results presented in this article have confirmed this hypothesis and provided the opportunity to apply for new patent solutions of a special throttle of the leak control and pressure regulating system. The proposed new leakage-based improvements could increase the efficiency of existing systems based on proportional-integral-derivative controller and could also be installed in new buildings.


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