<p>Proportional Integral Derivative (PID) controllers are <a href="http://www.thesaurus.com/browse/extensively">extensively</a> used in practical industries to control the speed of DC Motors. The single weakness of PID controllers is their sensitivity to variation in parameters and operating conditions; thus, tuning the controller gains to adapt with these variations presents a practical challenge. In this paper, an adaptive mechanism that utilizes a Recursive Least Square (RLS) algorithm, with rate limiters, is implemented to perform an online self-adjusting of each of the PID gains in order to achieve Adaptive PID (APID) controller that will accommodate to system variations. MATLAB/ Simulink software is used to implement and simulate APID control of a Chopper-Fed DC motor. A conventional PID control system is also designed and simulated to obtain results that can be used to judge the performance of the APID controller. Results proved that the APID controller forced the motor speed to track the reference input with <a href="http://www.thesaurus.com/browse/insignificant">insignificant</a> tracking error, and also managed to attain the motor speed at its desired value, regardless of the load changes inflected on the motor. This enhances both transient and steady-state speed responses.</p>
In this research, has been a developed modular approach for investigation of the dynamic behavior and analysis the steady -state and transient cases for a three-phase induction motor when it is fed with a balanced and unbalanced voltage , and analysis the behavior of the Torque-Speed characteristics at various conditions. This analysis is done systematically by development two mathematically models. Where the first model is proposed to simulate the dynamic behavior of the motor when supplying it at balanced and unbalanced voltage in Matlab/Simulink by using d-q axis theory in the reference frame. This model can investigate and described in details the behavior of the induction motor parameters, and enables the researcher to calculate or investigate any variable for an induction machine parameter ; (e.g. The voltage, current, flux, speed and torque as a function of time) in both cases transient and steady state , when the motor in operation state [11-16]. The other model is proposed to simulate in the Microsoft Excel program, by using the ratio between the conventions of the electromagnetic torque equation(Tem) and maximum torque equation (Tmax) . To study and analysis the behavior of the Torque-Speed characteristics for a 3-phase induction motor. Where this models study's by using Excel program's and Matlab / Simulink to simulation the effect of the various parameters on the dynamic behavior of the motor such as inserting variable external resistance in series with rotor circuit , and when supplying the stator by variable voltage. These Mathematical models could be used for a wide range of motors which has a various horse powers , which needing it in a scientific research and practical applications.
In the current study, the general mathematical model for the calculation and analysis of asynchronous systems and transient cases in asynchronous synchronous large electrical machines was developed. The theory of magnetic fields in the teeth's circuits with a smooth surface of the rotor was used and at the same time, high harmonics of magnetic fields and its effect on the transient cases was also calculated. Performance curves were investigated using Matlab codes and evaluated under different values of factor. The results confirmed the possibility of improving the noise harmonics on the sinusoidal wave form, which is reflected on the machines starting.
Creating a color image features is an important and vital task, because these features can be used in a color image recognition system, so decreasing the effort of clustering, and decreasing the feature extraction time will lead to better and efficient color images recognition system. In this paper research we will investigate how using color image histogram will enhance the recognition system, without doing any changes in the accuracy and uniqueness of the kmeans method of features extraction.
<p>In this case study, two polycrystalline solar modules were installed outdoors (irradiated by sunlight) and indoors (irradiated by artificial lights). The solar cells in both cases were installed using different color filters that allowed the passage of certain light frequencies. The amount of energy produced by each module were measured and compared to a reference module with no filter. The results indicated the variable response of polycrystalline solar cells to natural and artificial light sources, being more responsive in both cases to red band color as could be deduced from their % current outputs (72.5% sunlight radiation; 84.38% artificial light sources). Other colors, including yellow, green, orange and violet afforded acceptable outputs. The results indicated that electrical outputs of indoor solar cells decreased when colored filters were used, but red filter in general afforded the maximum outputs, for both the artificially radiated indoor and naturally radiated outdoor solar cells. The case study suggests the possible complementary advantage of using indoor mounted solar cells for the production of electricity during artificial illumination period of the day.</p>
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.