Recent Advances in Electrical & Electronic Engineering - Volume 13, Issue 3, 2020

Objective: Permanent Magnet Synchronous Motor (PMSM) drives require speed/position information for the efficient performance of industrial applications. Methods: A sensor-based method utilizes sensors for extracting this information which increases weight, size, and cost of the drive system, whereas the sensorless method utilizes model-based estimators which depend on motor parameters. Thus, the performance degrades due to the parameter variations. Model Reference Adaptive System (MRAS), a robust estimation technique has been implemented for speed/position estimation. Conclusion: In this paper, sensor-based and sensorless methods have been studied and the performance has been compared in four operating environments of speed and torque values. The comparative results of both methods have been shown in the MATLAB/Simulink environment.

Background: Advancements in Power Electronics made a huge breakthrough in the industrial sector majorly in the development of Switched Reluctance Machines (SRM). The main objective of this paper is to develop a two Phase H-bridge converter for 250W SRM and compare its advantages and disadvantages over the other converters. Methods: A time based simulation has been carried out to evaluate the performance of the converter at various loads. Different parameters of the machine and converter are studied and the results are verified experimentally. Results: The obtained test results of the converter performance are found to be in good agreement with the simulation and the efficiency of the converter is compared with the existing R-Dump topology. Conclusion: It is concluded that the proposed H-Bridge converter for a two phase SRM is better than the R-Dump converter in terms of efficiency and reduced size.

Background: The multiuser scenarios using the recently proposed wireless communication scheme, namely Beam Index Modulation (BIM), are investigated in this paper. Methods: Both transmitter node and multiple receiver nodes are equipped with analogue beamforming networks, transforming physical wireless propagation channels to virtue channels in beam domain. Results: Under the non-line-of-sight (nLoS) multi-scattered channel conditions, which are likely the cases for some future wireless communication systems operating at higher frequency bands. Conclusion: It has been proved, both through simulations and experiment, at 10 GHz in an indoor environment, that the proposed BIM is able to enhance the system performance at high Signal-to-Noise Ratio (SNR) scenarios, with regard to the sum spectral efficiency, with only a single Radio Frequency (RF) chain.

Background: The spot, streak and rust are the most common diseases in maize, all of which require effective methods to recognize, diagnose and handle. This paper presents a novel image classification approach to the high accuracy recognition of these maize diseases. Methods: Firstly, the k-means clustering algorithm is deployed in LAB color space to reduce the influence of image noise and irrelevant background, so that the area of maize diseases could be effectively extracted. Then the statistic pattern recognition method and gray level co-occurrence matrix (GLCM) method are jointly used to segment the maize disease leaf images for accurately obtaining their texture, shape and color features. Finally, Support Vector Machine (SVM) classification method is used to identify three diseases. Results: Numerical results clearly demonstrate the feasibility and effectiveness of the proposed method. Conclusion: Our future work will focus on the investigation of how to use the new classification methods in dimensional and large scale data to improve the recognizing performance and how to use other supervised feature selection methods to improve the accuracy further.

Objective: This article presents a comparative study between the direct control for a Doubly- Fed Induction Generator (DFIG) in the healthy and faulty mode. Methods: First with classical IP controller then Linear Quadratic Gaussian (LQG) controller which propose an ensemble of Linear Quadratic Regulator and Kalman filter for the state estimation. The developed model of the machine allows the simulation of the inter-turn short circuit in the stator. The use of the LQG method provides very good performance for motor operation and robustness of the control law despite the external perturbation. The performance of the control is compared to a classical controller's PI. Results: The obtained results demonstrate that this type of controller allows the alleviation of the mechanical stress and it ensures good performances under fault, the continuity of this system is ensured. Conclusion: The simulation has been carried out using a MATLAB script and the results are presented.

Objective: In this paper, Decode-and-Forward (DF) mode is deployed in the Relay Selection (RS) scheme to provide better performance in cooperative downlink Non-orthogonal Multiple Access (NOMA) networks. In particular, evaluation regarding the impact of the number of multiple relays on outage performance is presented. Methods: As main parameter affecting cooperative NOMA performance, we consider the scenario of the fixed power allocations and the varying number of relays. In addition, the expressions of outage probabilities are the main metric to examine separated NOMA users. By matching related results between simulation and analytical methods, the exactness of derived formula can be verified. Results: The intuitive main results show that in such cooperative NOMA networks, the higher the number of relays equipped, the better the system performance can be achieved. Conclusion: DF mode is confirmed as a reasonable selection scheme to improve the transmission quality in NOMA. In future work, we will introduce new relay selections to achieve improved performance.

Background: This paper is devoted to adaptive feedback linearization based stabilization of a two-axis gimbal platform. Methods: A Lyapunov based adaptation mechanism is proposed for stabilization of a two axes gimbal system through a feedback linearized control structure. The uncertainty of the products of inertia is incorporated in the design procedure. Results: The performed computer simulations demonstrate the robust performance of the proposed two-axis gimbal stabilizer considering the cross-coupling effects between inner and outer gimbals. Conclusion: The proposed control structure could be utilized in guided missiles, spacecraft, and navigation systems.

Background: With the increasing development of voltage source converter based high voltage direct current (HVDC), it will become a reality to interconnect different DC networks into DC grid with DC-DC converters. Methods: In this paper, three operation scenarios for the DC grid with DC-DC converters are proposed, by which the DC networks can reinforce each other with relative independence. In order to achieve the flexible switching of the proposed scenarios, the DC-DC combined control and principle of parameter selection are presented. In addition, two coordination controls for different scenarios are given to optimize the distribution of unbalanced power when the disturbances occur in the grid. With the proposed scenarios and control strategy, the impacts caused by the disturbances are alleviated and the uninterrupted operation of the grid is guaranteed. Results: A simulation model is established on the PSCAD/EMTDC and the simulation results verify the effectiveness of the proposed operation scenarios and control strategy. Conclusion: Finally, the effectiveness of the proposed operation scenarios and control strategy is verified by the simulation results in PSCAD/EMTDC.

Objective: The use of multiple-stage cycloconverters is suitable for variable-frequency speed control of high-voltage, large-capacity motors, for which it is sometimes necessary to establish separate controls for variable-frequency operation and the start-up phase. This approach effectively limits the starting current of the large-capacity motor by switching the phase relationship of the triple circuit’s output voltages to control the overall output voltage. Methods: We analyze a triple circuit using voltage vector analysis and simulation analysis with MATLAB modeling. Results: We find that our triple soft-start control strategy can be applied to large-capacity motors, as this strategy results in a pure sine wave output voltage and current, and maintains balance in the three-phase voltage during startup. Conclusion: In order to further decrease these types of effects, we will conduct more research on a cycloconverter that has six stages of the converter circuit, rather than the three stages mentioned before. Furthermore, the sextuple cycloconverter, which can be used to practically drive high capacity pumps or fans, will be developed by combining the “phase hopping” method and the soft-start method mentioned in this paper.

Background: As more and more renewable energy such as wind energy is connected to the power grid, the static economic dispatch in the past cannot meet its needs, so the dynamic economic dispatch of the power grid is imperative. Methods: Hence, in this paper, we proposed an Improved Differential Evolution algorithm (IDE) based on Differential Evolution algorithm (DE) and Artificial Bee Colony algorithm (ABC). Firstly, establish the dynamic economic dispatch model of wind integrated power system, in which we consider the power balance constraints as well as the generation limits of thermal units and wind farm. The minimum power generation costs are taken as the objectives of the model and the wind speed is considered to obey the Weibull distribution. After sampling from the probability distribution, the wind speed sample is converted into wind power. Secondly, we proposed the IDE algorithm which adds the local search and global search thoughts of ABC algorithm. The algorithm provides more local search opportunities for individuals with better evolution performance according to the thought of artificial bee colony algorithm to reduce the population size and improve the search performance. Results: Finally, simulations are performed by the IEEE-30 bus example containing 6 generations. By comparing the IDE with the other optimization model like ABC, DE, Particle Swarm Optimization (PSO), the experimental results show that obtained optimal objective function value and power loss are smaller than the other algorithms while the time-consuming difference is minor. The validity of the proposed method and model is also demonstrated. Conclusion: The validity of the proposed method and the proposed dispatch model is also demonstrated. The paper also provides a reference for economic dispatch integrated with wind power at the same time.

Background and Introduction: The proposed control law is designed to provide fast reference tracking with minimal overshoot and to minimize the effect of unknown nonlinearities and external disturbances. Methods: In this work, an enhanced composite nonlinear feedback technique using adaptive control is developed for a nonlinear delayed system subjected to input saturation and exogenous disturbances. It ensures that the plant response is not affected by adverse effect of actuator saturation, unknown time delay and unknown nonlinearities/ disturbances. The analysis of stability is done by Lyapunov-Krasovskii functional that guarantees asymptotical stability. Results: The proposed control law is validated by its implementation on exothermic chemical reactor. MATLAB figures are provided to compare the results. Conclusion: The simulation results of the proposed controller are compared with the conventional composite nonlinear feedback control which illustrates the efficiency of the proposed controller.

Background: The lighting researchers are keenly looking for the huge benefits of the internet of things on an open platform which provides the cost gains in addition to other environmental benefits. Connected systems interact with the software and analyse real-time building conditions, and feed information into the building controls network. Methods: This paper presents a wireless networked system for lighting control in buildings which connect the power of the Internet of Things. After analysing the ZigBee network on QualNet v7.4, a Digi Mesh network was set up using XBee modules using the XBee Configuration and Test Utility [XCTU] Software v6.3.11. The ThingSpeak cloud platform along with MATLAB 2017b provides the necessary cloud support to enable this network to communicate over the internet. The results indicate that the XBee S2C module functioning in the API mode when flashed with the DigiMesh firmware offers the best option for forming a self-healing mesh network. An aggregator node acts as an information sink and collects the sensor data from all the sensor nodes and passes it on to the cloud via the Raspberry gateway. Results: The algorithm on the cloud can read this sensor data and compute the necessary Pulse Width Modulation [PWM] signals required to control the brightness of a dimmable LED luminaire. The system also takes into consideration the zone-wise occupancy in the room while computing the PWM values to be sent to the luminaires. Conclusion: The use of the concept of open platform sensors and actuators is the significance of the work.

Background: In this paper, a novel technique for reactive power management of the Ultra High Voltage (UHV) lines having voltage level of 1200 kV line and above is suggested. The UHV power grid has to frequently face the problems associated with the power- frequency and switching over-voltages. Methods: The technique involves the use of three-phase UHV Transformers as a Controlled Shunt Reactor (CSR) in combination with the use of a fixed reactor. The performance of the UHV AC transmission line is studied using PSCAD software and working of CSR is evaluated. Results: Standard parameters of the proposed Wardha-Aurangabad 1200 kV transmission line in India are considered for simulation model. The use of CSR has been found to be effective in mitigating system problems. Conclusion: The system can be used for maintaining voltage profile, resulting in enhancement of the reliability of the UHV transmission system.

Background: Aiming at the three-phase voltage source PWM rectifier (VSR), there have been some researches on the neural network control strategies, but the unbalanced power grid condition is always neglected. Meanwhile, about the self-detection technology of the unbalanced power grid voltage, there are still few researches. Methods: Under the unbalanced power grid conditions, this work presents a power grid voltage sensorless control strategy of the three-phase VSR. Based on the radial basis function neural network (RBF) theory, a newly PI controller with parameter self-tuning function is studied, and the RBF-PI controller is used for the closed-loop controls of the voltage and current variables. By means of T/4 delay method, the positive- and negative-sequence components of the power grid side current, and those of the equivalent virtual flux-linkage of unbalanced power grid are extracted. From the equivalent virtual flux-linkage, the unbalanced power grid voltage is reconstructed online. Results: Under the load mutation condition, the power grid voltage sensorless control of threephase VSR is achieved, the system response characteristics are analyzed. From the simulation experimental results, it can be seen that the unbalanced power grid voltage can be quickly tracked, and the sinusoidal control of the power grid side current can be achieved. In addition, the control system has a series of advantages, such as a faster dynamic response speed, a stronger robustness and a smaller DC side voltage ripple. Conclusion: The proposed unbalanced power grid voltage sensorless control strategy of threephase VSR is effective.

The article entitled “Power Experimental Optimization of Horizontal Axis Wind Turbine”, by Sadek Ameziane, Abdesselem Chikhi and Mohammed Salah Aggouner, has been retracted on the request of Prof. Saïd DRID, Senior Member IEEE. He informed Dr. Huiyu Zhou (Editor-In-Chief of EENG) that Sadek Ameziane is his PhD student and almost the entire content of this paper was already published in two conferences and in his master dissertation in French language. The Corresponding Author Dr. Abdesselem Chikhi has included the names of the co-authors, Dr. Sadek Ameziane, Dr. Mohammed Salah Aggouner without taking the consent of Prof Saïd DRID and the manuscript was published in the journal, Recent Advances in Electrical and Electronic Engineering (EENG). Kindly see Bentham Science Policy on Article retraction at the link given below: https://benthamscience.com/journals/recent-advances-in-electrical-and-electronic-engineering/author-guidelines/ Submission of a manuscript to the respective journals implies that all authors have read and agreed to the content of the Copyright Letter or the Terms and Conditions. As such, this article represents a severe abuse of the scientific publishing sys-tem. Bentham Science Publishers takes a very strong view on this matter and apologizes to the readers of the journal for any inconvenience this may cause. Bentham Science Disclaimer: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.