scholarly journals Hierarchical set-point optimization and feedforward strategy for collector defocusing of a solar plant

Solar Energy ◽  
2021 ◽  
Vol 220 ◽  
pp. 282-294
Author(s):  
A.J. Sánchez ◽  
A.J. Gallego ◽  
J.M. Escaño ◽  
E.F. Camacho
Keyword(s):  
2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Fina Supegina

Hydroponics is one of planting method that use water as a medium of plants growth, in this technique, mineral solution added into the water solvent, allowing the nutrient uptake process by the plants.  Farming by hydroponic method must pay attention to the following parameters namely, temperature, humidity, the level of water needs and nutrients and also the level of sunlight need for photosynthesis process.  This research used hydroponic technique in hydroponic growth room, and  there is a LED growth light as an alternate of sunlight, due to this room is closed without sunlight.  There are outputs displayed in monitoring system namely, temperature sensor, humidity sensor, ultrasound sensor to detect height of the plant and water level sensor to measured height of the water as a medium of the plant.  Results of measured sensor in hydroponic growth room explained as the following:  fan cooler worked when temperature , and humidity  .  Water pump worked when water level is less than 50% accordance set point.  Control on LED Growth Light and LED Bulb when LDR sensor reached set point > 500 in bright condition, and < 500 in dark condition respectively. The average of Time update/received data in thing speak web is 2.4 second. Keywords: Smart Control, Hydroponic, IoT, Monitoring


1980 ◽  
Vol 45 (11) ◽  
pp. 2903-2918 ◽  
Author(s):  
Josef Horák ◽  
Zina Valášková ◽  
František Jiráček

Algorithms have been presented, analyzed and experimentally tested to stabilize the reaction temperature at constant inlet temperature and composition of the feed by controlled dispensing of the catalyst. The information for the control element is the course of the reaction temperature. If the temperature of the reaction mixture is below the set point, the catalyst is being fed into the reactor at a constant rate. If the reaction temperature is higher the catalyst dispenser is blocked; dispensing of the catalyst is not resumed until the set point temperature has been reached again. The amount of catalyst added is a function of the duration of the switching cycle. The effect has been discussed of the form of this function on the course of the switching cycle. The results have been tested experimentally on a laboratory reactor controlled in an unstable steady state.


2021 ◽  
Vol 233 ◽  
pp. 110666
Author(s):  
Won Hee Kang ◽  
Yeobeom Yoon ◽  
Je Hyeon Lee ◽  
Kwan Woo Song ◽  
Young Tae Chae ◽  
...  
Keyword(s):  

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 423
Author(s):  
Gun-Baek So

Although a controller is well-tuned for set-point tracking, it shows poor control results for load disturbance rejection and vice versa. In this paper, a modified two-degree-of-freedom (2-DOF) control framework to solve this problem is proposed, and an optimal tuning method for the pa-rameters of each proportional integral derivative (PID) controller is discussed. The unique feature of the proposed scheme is that a feedforward controller is embedded in the parallel control structure to improve set-point tracking performance. This feedforward controller and the standard PID con-troller are combined to create a new set-point weighted PID controller with a set-point weighting function. Therefore, in this study, two controllers are used: a set-point weighted PID controller for set-point tracking and a conventional PID controller for load disturbance rejection. The parameters included in the two controllers are tuned separately to improve set-point tracking and load dis-turbance rejection performances, respectively. Each controller is optimally tuned by genetic algo-rithm (GA) in terms of minimizing the IAE performance index, and what is special at this time is that it also tunes the set-point weighting parameter simultaneously. The simulation results performed on four virtual processes verify that the proposed method shows better performance in set-point tracking and load disturbance rejection than those of the other methods.


Clean Energy ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 57-78
Author(s):  
Sohaib Nasr Mohamed Abdalla ◽  
Hakan Özcan

Abstract Developing nations have a critical need to increase electricity supply. Sudan has much unrealized potential for generating solar energy, particularly in the northern region. This research study focuses on designing a 1-GW solar power station in northern Sudan using the PVsyst7.0 software program. To determine the appropriate location for the solar-energy station, 14 criteria were evaluated. This process is generic and suitable for use in any other country. The method for conducting cash-flow estimates and return on investment is illustrated in the economic evaluation. The city of Dongola, the capital of the northern state, was selected because of its high annual irradiance on a horizontal surface at ~2333.2 kWh/m2. The simulation results show that the annual optimum tilt angle of inclination for photovoltaic (PV) modules is 30°, the energy production is 1 979 259 MWh/yr and the average annual performance rate is 0.810. In addition, the electric power consumption per capita in Sudan is 269 kWh/yr, so the proposed solar power plant with 1 979 259 MWh/yr can provide energy to 7.4 million people per year annually and reduce carbon emissions by ~18 million tons of carbon dioxide per year. Economic calculations show that the levelized cost of electricity (LCOE) is $0.06/kWh, the discounted payback period is ~11 years and the net present value is $635 291 000. As a result, the proposed grid-connected PV solar plant is considered economically, technically and environmentally feasible in Sudan.


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