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This paper proposes a jellyfish search algorithm (JSA)-based offline method to design a DC voltage controller of AC/DC front-end converter (FEC) in a doubly fed induction generator (DFIG)-based wind energy conversion system (WECS). First, a multi-objective tuning problem is formulated using a full-order converter model to achieve maximum utilization of converter parameters in controller design. Next, a normalized mono-objective problem is developed using a utopia-tracking approach to reduce the computational complexity in design. Finally, the mono-objective problem is solved using JSA to enhance the controller performance by obtaining optimal gain values for the controller. A comparative study is performed with other metaheuristic optimization techniques to justify the use of JSA in this application. The results confirm that the accuracy of the JSA-based approach is higher, whereas the execution time of the method is lower than the other methods. Furthermore, to validate the performance of the proposed approach, a DFIG-based WECS is modeled and simulated using OPAL-RT real-time simulator. A grid voltage-oriented vector control is used as the overall control algorithm for the FEC. Unlike the conventional pole-zero cancellation method, the proposed approach provides no voltage overshoot during voltage development. Compared to the published literature, it also ensures 40.65% lesser voltage deviation without any overcurrent, irrespective of wind speed and load variations. [ABSTRACT FROM AUTHOR]

An integrated dynamic simulation model of a directly coupled solar photovoltaic pump-operated drip irrigation system is developed and presented in this study. The model is applied for system evaluation and preparing a plan of drip irrigation system operation to meet the irrigation schedule of the Okra crop considered in the case study. The fundamental mathematical expressions of the solar photovoltaic array, variable frequency drive, submersible pump, and drip irrigation system are used to create a generic simulation model in the Matlab/Simulink environment. The hourly solar irradiation, temperature, and groundwater level are input parameters to the model. The output such as solar photovoltaic power, pump discharge and pressure head, and emitter discharges are simulated on an hourly basis. The simulated values of these parameters for the same period are compared with the measured values and the model accuracy is evaluated statistically. The coefficient of determination (R2) greater than 0.98 for all the subsystems shows good agreement between the measured and the simulated values. Further, the higher Nash–Sutcliffe model efficiency (> 0.77) and lower negative coefficient of residual mass statistic (close to 0) indicates the model is performing perfectly with a slight tendency to overestimate. The developed simulation model is applied in a case study to operate different subunit manifolds of a drip irrigation system installed in an Okra crop field of 1.2 ha. The total utilizable solar photovoltaic energy is found between 14 and 20 kWh/day. The satisfactory emission uniformity (greater than 85%) is found for the inlet pressure greater than 78.45 kPa. The suitable time at which sufficient pump pressure head is generated to operate drip irrigation system is found from IST 9.00 h to 15.00 h. Accordingly, a plan of operation of different sub-main manifolds of the drip irrigation system is prepared. Based on the analysis of simulation results, it is found that an additional area of 0.19 ha Okra crop can be brought under irrigation using the same solar photovoltaic powered pumping system for the case study. The combined simulation of all the subsystem components provides useful information on dynamic photovoltaic power, pump discharge, pressure head, and emitter discharge in a short time to the operator or designer for decision making. The developed model and approach presented in this research is unique for scheduling real-time operation of different sub-main manifolds of drip irrigation system, which can enhance the effective utilization of photovoltaic energy and water. [ABSTRACT FROM AUTHOR]

This paper aims to present future energy and flow rate generation scenario of conventionally designed photovoltaic water pumping system for irrigation using projected climate change and degradation factor. The mean monthly water flow rate from the pump was predicted for different months using expected power for 16S × 1P PV array configuration. The mean monthly expected power from solar PV system was estimated using climate change forecast of solar radiation and temperature for 30 years of lifetime period of solar PV pumping system. The estimation of expected power at predicted solar radiation and temperature also includes the yearly system components degradation rate. The water flow rates were predicted using an experimentally developed mathematical model for a given pump. The experimental model simulates the water flow rate for various solar power and heads (30 m, 40 m and 50 m). The field data were obtained using a pumping test facility located at a farm site of IIT Kharagpur (India). It was found that the flow rate increases with the increase in pump power for each head. The yearly pattern of predicted energy and flow rate for different months showed a decreasing trend as the projected temperature rise and component degradation reduces the energy yield from the PV array. The results indicated that the overall reduction in the capacity of a PV system is in the range of 25–27% for different months in which climate change (rise in temperature) showed minor effect (3%) and can be neglected. The mitigating measures for energy loss are required to fulfil future irrigation demand. [ABSTRACT FROM AUTHOR]

Ten quantitative morphological characters were studied in 56 Morus alba L. trees representing three natural populations from the trans-Himalayan Ladakh region. The altitude of collection sites ranged from 2815 to 3177 m above the sea level (asl). Coefficient of variation (CV) showed high phenotypic variation in M. alba. Linear regression analysis revealed that leaf and fruit size decreases with an increase in altitude. High CV was observed for leaf length, leaf width, petiole length, leaf area, inter-nodal distance, number of nodes, bud length, fruit length, fruit width and fruit weight. Similarly, a high phenotypic plasticity index was observed for bud length, leaf length, leaf width, petiole length, leaf area, inter-nodal distance, number of nodes, fruit length, fruit width and fruit weight. For every 100 m increase in altitude, leaf length, leaf width and leaf area decreased by 1 cm, 0.8 cm and 16.6 cm, respectively. Analysis of covariance showed a predominant altitudinal effect on the morphological characters in comparison to the population effect. A small change in the altitude caused significant change in the plant morphological characteristics. The present investigation represents to our knowledge the first study addressing phenotypic variation in mulberry along an altitudinal gradient. [ABSTRACT FROM AUTHOR]

Sequence-related amplified polymorphism markers were used to assess the genetic structure in three natural populations of Morus alba from trans-Himalaya. Multilocation sampling was conducted across 14 collection sites. The overall genetic diversity estimates were high: percentage polymorphic loci 89.66%, Nei's gene diversity 0.2286, and Shannon's information index 0.2175. At a regional level, partitioning of variability assessed using analysis of molecular variance (AMOVA), revealed 80% variation within and 20% among collection sites. Pattern appeared in STRUCTURE, BARRIER, and AMOVA, clearly demonstrating gene flow between the Indus and Suru populations and a geographic barrier between the Indus-Suru and Nubra populations, which effectively hinders gene flow. The results showed significant genetic differentiation, population structure, high to restricted gene flow, and high genetic diversity. The assumption that samples collected from the three valleys represent three different populations does not hold true. The fragmentation present in trans-Himalaya was more natural and less anthropogenic. [ABSTRACT FROM AUTHOR]