scholarly journals (0091) Control of Open end Induction Motor by Multi-objective GA based Selective Harmonic Elimination PWM to reduce Zero Sequence Currents and Torque Ripples

Author(s):  
Jaroslaw Milewski ◽  
kalyan kumar koppolu ◽  
K Anuradha ◽  
M Surya Kalavathi ◽  
Arkadiusz Szczęśniak

A Double inverter powered induction motor with open stator winding has few benefits, including excessive error forbearance functionality, great flexibility and lesser rating of dc input voltage etc. For this Configuration, two types of Modules can implement they are Non-isolated DC link and Isolated DC link. In these two, Non-isolated DC link is a good choice due to effective DC-link utilization and ruggedness, which is very beneficial in many applications. However, this module produces more zero sequence currents (Z-SC) by means of common mode (CMMD) voltage, which flows through Dc bus. The circulation of Z-SC must as little as feasible since it merely does rise the amplitude of currents in all phases. High ripple frequency of currents and torque, In addition resulting extra loss, which not alone reduces the efficiency, but loading ability and quickens the aging of drive. The triplen harmonics can denote meticulously as harmonics with integer of three times the frequency at fundamental, when they are in Phase in all Phases forms the Z-SC. In this paper, a novel SHE method is chosen to target triplen harmonics in Single DC Source Module (Non- isolated) and holding preferred fundamental quantity, which aids in improving the torque handling ability of the motor. In addition, the investigation of dual inverter fed OEW-IM with both common DC source as well as separate DC sources also explored by SHE for different number of switching angles and variable Modulation Index (MI) towards the torque ripples and Z-SC reduction are given. The foremost challenge related with SHE method is that resolving a set of higher order nonlinear equations with number of variables. A Multi-objective GA method provided for that challenge which effects the reduction in Z-SC so that torque ripples will be minimised. Moreover, the novel SHE method reduces more number of harmonics than the conventional SHE, which further decreases TH-D with decent fundamental quantity. For validation, the essential mathematical formulations and simulation results presented.

2011 ◽  
Vol 135-136 ◽  
pp. 667-672
Author(s):  
Xi Wei Zhou ◽  
Gui Ping Wang ◽  
Chen Dong Duan ◽  
Chun Ling Wu

The asynchronous induction motor has obtained more applications in electric vehicle (EV) or hybrid EV drive systems. But, the parameter’s variations of the motor and the harmonics of the voltage source inverter are the two problems influence control performance of EV Drive Systems. Above all, this Paper discusses several main factors which influence harmonics elimination, and then, describes an effective online method for identifying both stator and rotor resistance. The novel method uses Suboptimal Multiple Fading Extended Kalman Filter (SMFEKF) which is a kind of strong tracking filters can accomplish Parameter Identification. An important advantage of this method is that it offers a parallel search way can overcome local optima so as to find the globally optimal solution. Together with harmonic elimination Algorithm which improved the power factor of the drive and weaken the injected low-order harmonics to the induction motor, robust speed control of induction motor can obtained easily. The simulative results confirm that the proposed method has efficiency to EV Drive Systems.


Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 126
Author(s):  
Hai-Feng Ling ◽  
Zheng-Lian Su ◽  
Xun-Lin Jiang ◽  
Yu-Jun Zheng

In a large-scale epidemic, such as the novel coronavirus pneumonia (COVID-19), there is huge demand for a variety of medical supplies, such as medical masks, ventilators, and sickbeds. Resources from civilian medical services are often not sufficient for fully satisfying all of these demands. Resources from military medical services, which are normally reserved for military use, can be an effective supplement to these demands. In this paper, we formulate a problem of integrated civilian-military scheduling of medical supplies for epidemic prevention and control, the aim of which is to simultaneously maximize the overall satisfaction rate of the medical supplies and minimize the total scheduling cost, while keeping a minimum ratio of medical supplies reservation for military use. We propose a multi-objective water wave optimization (WWO) algorithm in order to efficiently solve this problem. Computational results on a set of problem instances constructed based on real COVID-19 data demonstrate the effectiveness of the proposed method.


2021 ◽  
Vol 40 (5) ◽  
pp. 10043-10061
Author(s):  
Xiaoping Shi ◽  
Shiqi Zou ◽  
Shenmin Song ◽  
Rui Guo

 The asset-based weapon target assignment (ABWTA) problem is one of the important branches of the weapon target assignment (WTA) problem. Due to the current large-scale battlefield environment, the ABWTA problem is a multi-objective optimization problem (MOP) with strong constraints, large-scale and sparse properties. The novel model of the ABWTA problem with the operation error parameter is established. An evolutionary algorithm for large-scale sparse problems (SparseEA) is introduced as the main framework for solving large-scale sparse ABWTA problem. The proposed framework (SparseEA-ABWTA) mainly addresses the issue that problem-specific initialization method and genetic operators with a reward strategy can generate solutions efficiently considering the sparsity of variables and an improved non-dominated solution selection method is presented to handle the constraints. Under the premise of constructing large-scale cases by the specific case generator, two numerical experiments on four outstanding multi-objective evolutionary algorithms (MOEAs) show Runtime of SparseEA-ABWTA is faster nearly 50% than others under the same convergence and the gap between MOEAs improved by the mechanism of SparseEA-ABWTA and SparseEA-ABWTA is reduced to nearly 20% in the convergence and distribution.


Author(s):  
Mohamed Chebaani ◽  
Amar Goléa ◽  
Med Toufik Benchouia ◽  
Noureddine Goléa

Purpose Direct Torque Control (DTC) of induction motor drives is a well-established technique owing to features such as fast dynamic and insensibility to motor parameters. However, conventional DTC scheme, based on comparators and the switching table, suffers from large torque and flux ripples. To improve DTC performance, this study aims to propose and implement a sensorless finite-state predictive torque control using extended Kalman Filter in dSPACE environment. Design/methodology/approach This paper deals with the design of an extended Kalman filter for estimating the state of an induction motor model and for sensorless control of systems using this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. Findings Simulation and experimental results reveal that the drive system, associated with this technique, can effectively reduce flux and torque ripples with better dynamic and steady state performance. Further, the proposed approach maintains a constant switching frequency. Originality/value The proposed speed observer have been developed and implemented experimentally under different operating conditions such as parameter variation, no-load/load disturbances and speed variations in different speed operation regions.


Author(s):  
MANASA S ◽  
BALAJI RAMAKRISHNA S ◽  
MADHURA S ◽  
MOHAN H M

This paper deals with study of Three phase Five Level and Seven Level inverter fed induction motor drive . Both five level and seven level are realized by cascading two H- bridges. The poor quality of voltage and current of a conventional inverter fed induction machine is due to the presence of harmonics and hence there is significant level of energy losses. The Multilevel inverter is used to reduce the harmonics. The inverters with a large number of steps can generate high quality voltage waveforms. The higher levels can follow a voltage reference with accuracy and with the advantage that the generated voltage can be modulated in amplitude instead of pulse-width modulation. An active harmonic elimination method is applied to eliminate any number of specific higher order harmonics of multilevel converters with unequal dc voltages. The simulation of three phase five and seven level inverter fed induction motor model is done using Matlab/Simulink. The FFT spectrums for the outputs are analyzed to study the reduction in the harmonics.


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