scholarly journals Software for analyzing the probability of collisions of birds with rotors of wind electrical installations

2018 ◽  
Vol 6 (4) ◽  
pp. 1-18
Author(s):  
Viacheslav Osadchyi ◽  
Volodymyr Yeremieiev ◽  
Kateryna Osadcha
Keyword(s):  
Wind Farm ◽  
Operating Conditions ◽  
Time Interval ◽  
Bird Flight ◽  
Heritage Foundation ◽  
Power Stations ◽  
Probability Of Collision ◽  
Merops Apiaster ◽  
One Year ◽  
Bird Collisions

The program "Birds" has been developed for analyzing the risks of bird collisions with turbines of wind power stations. The mathematical model of the program is based on the recommendations of the Scottish Natural Heritage Foundation. The source database contains the necessary information in relation to the operating conditions of the wind farm "Primorsk-1", which is supposed to be built on the coast of the Azov Sea in the Zaporizhia region. If necessary, the user can enter his own values and get results on the interaction of birds with wind turbine rotors on the following indicators: bird flight time through the rotor space, probability of collision of one individual with the turbine, depending on its flight characteristics and parameters of the wind electrical installation, number of bird collisions at a given time interval. The program was tested using the example of calculating the number of collisions of birds with rotors during one year of operation of the Primorsk-1 wind park. It is shown that the probability of a collision of one bird with the rotor depends little on its geometric dimensions and is in the range of 11-15%. The total number of collisions of all birds on the territory of the wind farm will be 6,4 birds, which corresponds to 0.25 individuals per turbine. Most of this amount (about 4.8) refers to two species: Merops apiaster and Larus ridibundus.

scholarly journals Forecasting of the number of bird collisions with turbines in the territory of Pre-Azov region wind park using the route census method

2021 ◽  
Vol 280 ◽  
pp. 06010
Author(s):  
Volodymyr Yeremieiev
Keyword(s):  
Wind Power ◽  
Power Plants ◽  
Winter Season ◽  
Flight Path ◽  
Autumn Migration ◽  
Observation Site ◽  
Bird Flight ◽  
Wind Park ◽  
One Year ◽  
Bird Collisions

The information system has been designed to ensure the analysis of information on the monitoring results of the wind power plant (WPP) territory using the route census method. The database contains 48 fields, reflecting the monitoring results of birds’ behavior in the territory of WPP and processing the initial data: year, month and day of observation, a number of birds of this species, flight altitude, flight speed, direction of flight, coordinates of the bird registration point on the Google-map, average number of birds flying over the territory of the wind park at a given time, coordinates of the points of intersection of the bird flight path with the perimeter of the wind park or observation site, the length of bird flight path over the observation site, and other parameters. The analysis of distribution of birds in the territory of the “Primorsk-1” WPP according to the types of migration (forage, transit, nesting, and ground), direction of flight and altitude characteristics has been carried out. The total number of registered birds was 8927 specimens of 72 species, of which 802 specimens of 11 species were referred to the transit type, 2511 specimens of 32 species – to the forage type, 5614 specimens of 60 species were on the ground (ground type). Most birds (63%) belong to the ground type. 28% of birds were registered in the forage group, 9.0% of birds were flying in transit. The greatest activity of birds is manifested in the autumn migration season, when the transit group accounts for 77% of all annual transit flights. The proportion of birds of forage and ground types, registered in autumn, is 68% and 74%, respectively, of the total number of birds registered in autumn. In the group of ground birds, the overwhelming majority of specimens belong to the period of autumn migration (4141 birds or 74%). The least number was observed in the winter season (317 birds or 5.6%). The author proposes a mathematical model for analyzing birds’ interaction with turbines using the results of monitoring the territory of wind power plants by means of route census method. The model makes it possible to obtain information on the probability of different species of bird collisions with wind wheels and the number of collisions with turbines, depending on the flight characteristics of birds, parameters of wind parks and observation conditions in different seasons. In the risk zone of birds’ interaction with turbines, only specimens of one species, Buteo buteo, were observed. The calculated probability of one bird collision when passing through the wind wheel is 0.19. The anticipated number of bird collisions with turbines during one year of the “Primorsk-1” wind park functioning is in the range of 5.6÷6.7 specimens.

scholarly journals Frequency Scan–Based Mitigation Approach of Subsynchronous Control Interaction in Type-3 Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4626
Author(s):  
Faris Alatar ◽  
Ali Mehrizi-Sani
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Operating Conditions ◽  
Steady State Operation ◽  
Significant Damage ◽  
Frequency Scan ◽  
Type 3 ◽  
Phase Angles ◽  
Wind Energy Resources ◽  
Control Interaction

Integration of wind energy resources into the grid creates several challenges for power system dynamics. More specifically, Type-3 wind turbines are susceptible to subsynchronous control interactions (SSCIs) when they become radially connected to a series-compensated transmission line. SSCIs can cause disruptions in power generation and can result in significant damage to wind farm (WF) components and equipment. This paper proposes an approach to mitigate SSCIs using an online frequency scan, with optimized phase angles of voltage harmonic injection to maintain steady-state operation, to modify the controllers or the operating conditions of the wind turbine. The proposed strategy is simulated in PSCAD/EMTDC software on the IEEE second benchmark model for subsynchronous resonance. Simulation results demonstrate the effectiveness of this strategy by ensuring oscillations do not grow.

scholarly journals Performance Enhancement of Proposed Namaacha Wind Farm by Minimising Losses Due to the Wake Effect: A Mozambican Case Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4291
Author(s):  
Paxis Marques João Roque ◽  
Shyama Pada Chowdhury ◽  
Zhongjie Huan
Keyword(s):  
Wind Speed ◽  
Wind Power ◽  
Wind Turbines ◽  
Power Output ◽  
Wind Farm ◽  
Wind Farms ◽  
Operating Conditions ◽  
Wake Effect ◽  
Wind Generators ◽  
Wind Potential

District of Namaacha in Maputo Province of Mozambique presents a high wind potential, with an average wind speed of around 7.5 m/s and huge open fields that are favourable to the installation of wind farms. However, in order to make better use of the wind potential, it is necessary to evaluate the operating conditions of the turbines and guide the independent power producers (IPPs) on how to efficiently use wind power. The investigation of the wind farm operating conditions is justified by the fact that the implementation of wind power systems is quite expensive, and therefore, it is imperative to find alternatives to reduce power losses and improve energy production. Taking into account the power needs in Mozambique, this project applied hybrid optimisation of multiple energy resources (HOMER) to size the capacity of the wind farm and the number of turbines that guarantee an adequate supply of power. Moreover, considering the topographic conditions of the site and the operational parameters of the turbines, the system advisor model (SAM) was applied to evaluate the performance of the Vestas V82-1.65 horizontal axis turbines and the system’s power output as a result of the wake effect. For any wind farm, it is evident that wind turbines’ wake effects significantly reduce the performance of wind farms. The paper seeks to design and examine the proper layout for practical placements of wind generators. Firstly, a survey on the Namaacha’s electricity demand was carried out in order to obtain the district’s daily load profile required to size the wind farm’s capacity. Secondly, with the previous knowledge that the operation of wind farms is affected by wake losses, different wake effect models applied by SAM were examined and the Eddy–Viscosity model was selected to perform the analysis. Three distinct layouts result from SAM optimisation, and the best one is recommended for wind turbines installation for maximising wind to energy generation. Although it is understood that the wake effect occurs on any wind farm, it is observed that wake losses can be minimised through the proper design of the wind generators’ placement layout. Therefore, any wind farm project should, from its layout, examine the optimal wind farm arrangement, which will depend on the wind speed, wind direction, turbine hub height, and other topographical characteristics of the area. In that context, considering the topographic and climate features of Mozambique, the study brings novelty in the way wind farms should be placed in the district and wake losses minimised. The study is based on a real assumption that the project can be implemented in the district, and thus, considering the wind farm’s capacity, the district’s energy needs could be met. The optimal transversal and longitudinal distances between turbines recommended are 8Do and 10Do, respectively, arranged according to layout 1, with wake losses of about 1.7%, land utilisation of about 6.46 Km2, and power output estimated at 71.844 GWh per year.

Suicide in psychiatric inpatients in Ireland

1999 ◽  
Vol 16 (4) ◽  
pp. 127-131 ◽  
Author(s):  
Eleanor Corcoran ◽  
Dermot Walsh
Keyword(s):  
General Population ◽  
Suicide Rate ◽  
Psychiatric Inpatients ◽  
Time Interval ◽  
Hospital Inpatient ◽  
Fourfold Increase ◽  
Suicide Rates ◽  
Duration Of Illness ◽  
Secure Environment ◽  
One Year

AbstractObjectives:To establish suicide rates of psychiatric inpatients in Ireland and the characteristics, demographic, social and medical, of the patients involved.Method:Clinical, post mortem and inquest data on all such deaths from 1983-1992 were examined. Suicide rates were calculated using ‘person year method’.Results:The suicide rate for short stay inpatients (stay less than one year) was 319/100,000, and 118/100,000 for long stay patients. The average duration of illness at time of suicide was 10 years. A fourfold increase in suicide rate of inpatients over the century was associated with a similar increase in the suicide rate in the general population. Thirty five per cent of suicides were aged 25-34 years. The risk of suicide was higher the shorter the time interval after admission. Three quarters of suicide deaths in registered inpatients occurred away from hospital grounds.Conclusions:Social factors which contribute to an increase in the suicide rate in the general population are relevant to the increase in hospital inpatient suicides. More effective and comprehensive services to meet the needs of those with severe mental illness, particularly young adults, are essential. The results emphasise the importance of managing inpatients in a safe, secure environment. The person year method is appropriate for monitoring changes in suicide rates.

scholarly journals Treatment of industrial used water by UASB+CMBR process to produce industrial grade water for reuse

2018 ◽  
Vol 13 (2) ◽  
pp. 424-430 ◽  
Author(s):  
H. Noguchi ◽  
T. Niwa ◽  
Y. Nakamura ◽  
J. K. Agrawal ◽  
W. S. Ang ◽  
...  
Keyword(s):  
Ceramic Membrane ◽  
Operating Conditions ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
High Quality ◽  
Joint Project ◽  
Industrial Grade ◽  
One Year ◽  
Anaerobic Sludge Blanket

Abstract Joint project has been conducted in a demonstration plant with 1-MGD capacity at Jurong Water Reclamation Plant to produce high quality effluent through a combined process of up-flow anaerobic sludge blanket reactor and ceramic membrane bioreactor (UASB-CMBR). Water quality of the product and energy consumption met target which were evaluated after one-year operation. The joint project has further been conducted to optimize operating conditions including cleaning procedure. Recovery cleaning (RC) of the ceramic membrane was carried out after 18 months operation and permeability was recovered to be initial value. Stable filtration at 25 LMH was achieved after the RC. RO filtration test was also carried out to treat effluent from the UASB-CMBR. Stable operation in the RO system was achieved with flux of 15 LMH and recovery of 60%. Quality of RO permeates met criteria for industrial water. It is concluded that UASB-CMBR process with RO system can produce high quality water for reuse from industrial used water.

scholarly journals Insights into PCDD/Fs and PAHs in Biomass Boilers Envisaging Risks of Ash Use as Fertilizers

2020 ◽  
Vol 10 (14) ◽  
pp. 4951
Author(s):  
Helena Lopes ◽  
Susana Proença
Keyword(s):  
Unburned Carbon ◽  
Fly Ashes ◽  
Power Stations ◽  
Polycyclic Aromatic ◽  
Toxic Equivalents ◽  
One Year ◽  
Definition Of ◽  
And Control ◽  
The Impact ◽  
Biomass Ashes

Since ashes are a possible source of Persistent Organic Pollutants (POPs) contamination, their application in soils must be subject to more study and control. In this scope, feed residual forest biomasses and biomass ashes, collected along one year in four biomass power stations, were characterized mainly for their polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and Polycyclic Aromatic Hydrocarbons (PAHs) contents. The biomasses present concerning levels of Cl (0.04–0.28%) that may lead to PCDD/Fs formation. The biomasses also contain OCDD (29–260 ng/kg) and 1,2,3,4,6,7,8-HpCDD (35 ng/kg) that may contribute to increased Toxic Equivalents (TEQs) of ashes, possibly involving dechlorination and ash enrichment mechanisms. While the WHO2005-TEQs in bottom ashes (14–20 ng TEQ/kg) reaches the proposed limit (20 ng TEQ/kg) for ash use as fertilizers, in fly ashes (35–1139 ng TEQ/kg) the limit is exceeded. PAHs are below 0.02 mg/kg in bottom ashes and 1.5–2.5 mg/kg in fly ashes, complying with the proposed limit of 6 mg/kg. As bottom and fly ash streams may contain different ash flows, a clear definition of ash mixes is required. Correlations between unburned carbon (C), PAHs and PCDD/Fs were not found, which highlights the need for compulsory PCDD/Fs analysis in ashes, independently of their origin, burnout degree or levels of other contaminants. A sensitivity analysis was performed to evaluate the impact of handling non-detected values, which showed more impact for TEQs values close to the proposed regulatory limit of PCDD/Fs. These findings highlight the need to define reporting protocols of analytical results for risk assessments and conformity evaluation.

scholarly journals Full-Scale Wind Turbine Vibration Signature Analysis

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 63 ◽  
Author(s):  
Xavier Escaler ◽  
Toufik Mebarki
Keyword(s):  
Wind Farm ◽  
Power Spectra ◽  
Operating Conditions ◽  
Drive Train ◽  
Normal Operation ◽  
Common Source ◽  
Variable Speed ◽  
Data Set ◽  
Vibration Signature ◽  
Power Curves

A sample of healthy wind turbines from the same wind farm with identical sizes and designs was investigated to determine the average vibrational signatures of the drive train components during normal operation. The units were variable-speed machines with three blades. The rotor was supported by two bearings, and the drive train connected to an intermediate three-stage planetary/helical gearbox. The nominal 2 MW output power was regulated using blade pitch adjustment. Vibrations were measured in exactly the same positions using the same type of sensors over a six-month period covering the entire range of operating conditions. The data set was preliminary validated to remove outliers based on the theoretical power curves. The most relevant frequency peaks in the rotor, gearbox, and generator vibrations were detected and identified based on averaged power spectra. The amplitudes of the peaks induced by a common source of excitation were compared in different measurement positions. A wind speed dependency of broadband vibration amplitudes was also observed. Finally, a fault detection case is presented showing the change of vibration signature induced by a damage in the gearbox.

scholarly journals The Management of Infants for Cardiac Surgery under Deep Hypothermia

1972 ◽  
Vol 1 (2) ◽  
pp. 137-140 ◽  
Author(s):  
T. C. K. Brown ◽  
C. P. Clarke ◽  
E. A. Shanahan ◽  
B. D. McKie ◽  
H. M. Wood ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Heart Surgery ◽  
Open Heart Surgery ◽  
Deep Hypothermia ◽  
Operating Conditions ◽  
Temperature Gradients ◽  
Cerebral Oxygen ◽  
Physiological Effects ◽  
Surface Cooling ◽  
One Year

Deep hypothermia is now employed for open heart surgery in infants. The method of surface cooling infants to 25° C and then by-pass cooling down to 15–20° C prior to exsanguination is described. This provides a still heart and ideal operating conditions. The infants are re-warmed on by-pass. Some of the physiological effects of hypothermia and the methods employed to counteract these are discussed. The aims are to reduce temperature gradients, improve cerebral oxygen supply, avoid arrhythmias and secure haemostasis. The experience in 33 operations is outlined. Seventeen patients were under one year of age.

Predicting Activity Levels in Virtual Communities

2011 ◽  
pp. 387-389
Author(s):  
Ori B. Kushnir
Keyword(s):  
Virtual Communities ◽  
Interval Data ◽  
Activity Level ◽  
Data Series ◽  
Time Interval ◽  
Activity Levels ◽  
Data Set ◽  
Back Testing ◽  
One Year ◽  
Testing Standards

Data was collected from two communities: a smaller community with approximately 200 participants, but where the number of participants is precisely known; and a very large community, with thousands of participants, where the number of participants can only be estimated from the number of different nicknames used within a given time interval. Data from certain days when there were documented technical issues that may have affected activity has been removed from the sample. In both cases, we have taken one geographically centric data series and one global series, covering users in multiple areas and time zones. We use the number of messages sent in three-hour intervals as a proxy for the activity level in a community, as accurate figures regarding the number of messages viewed by unique persons are difficult to establish. This results in a data set of approximately 9,500 samples from each community, collected over a period of just less than four years. When fitting the models, we used accepted back-testing standards, relying on a fixed interval (one year) when fitting parameters and forecasting activity for any given point in time. One exception to this is seasonality adjustment, where we used the entire data set—this should not have a significant effect, as we made the same seasonal adjustment to the input for all models. Empirical results provided throughout the article are based on data from the larger community.

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