Research Articles
Industrial Electronics
Hamed Shadfar; Hamid Reza Izadfar
Abstract
Audible noise radiated by electrical machines is gaining more and more importance in the design process of electrical machines. The radial electromagnetic forces in induction motors play an important role in the production of audible noise and vibrations. The magnetic flux pulsations at the iron surfaces ...
Read More
Audible noise radiated by electrical machines is gaining more and more importance in the design process of electrical machines. The radial electromagnetic forces in induction motors play an important role in the production of audible noise and vibrations. The magnetic flux pulsations at the iron surfaces produce these radial forces which act on the stator and rotor structures. A squirrel-cage induction motor produces electromagnetic vibration and noise caused by interaction between many harmonic fluxes in the air gap. In this paper, a new structure of the squirrel cage rotor to improve the distribution of the air gap magnetic flux and reduce the electromagnetic forces and, consequently, the electromagnetic noise in a single-phase induction motor will be introduced. For this purpose, in the proposed design the rotor bars are located on the rotor according to a sinusoidal form. The results show that this structure of the rotor improves the dynamic behavior and many parameters such as electromagnetic forces, harmonic distortion of magnetic flux, and torque ripple.
Research Articles
Optimization
Maedeh Abedini Bagha; Kambiz MajidZadeh; Mohammad Masdari; Yousef Farhang
Abstract
Software-defined networking is a new network model proposed to solve the complexity of traditional network problems and facilitate dynamic network operation and management. The separation of the control plane from the data plane is the main idea of software-defined networks. Controllers are the operating ...
Read More
Software-defined networking is a new network model proposed to solve the complexity of traditional network problems and facilitate dynamic network operation and management. The separation of the control plane from the data plane is the main idea of software-defined networks. Controllers are the operating system of software-defined networks and are responsible for managing the entire network. It is essential to locate controllers appropriately to have a balanced topology while guaranteeing low latency. In this work, a metaheuristic algorithm is used for controller placement. First, the problem is formulated, and the network is partitioned by a clustering algorithm. Then, the seagull optimization algorithm is used to determine a suitable place for the controller in each network partition dynamically. Simulations are performed on the standard network topology from the internet topology zoo dataset to evaluate the proposed method. Simulation results reveal that the proposed method performs well in case of delay and load balancing compared with the state-of-the-art optimization algorithms.
Research Articles
Industrial Electronics
Allahverdi Azadrou; Siamak Masoudi; Shahla Gharaati
Abstract
This work presents finite element analysis, design, and construction of an improved linear switched reluctance motor for elevator application. In the proposed motor, both stator and translator have separate poles; thus, the motor is lighter and more appropriate for vertical motion applications. In addition, ...
Read More
This work presents finite element analysis, design, and construction of an improved linear switched reluctance motor for elevator application. In the proposed motor, both stator and translator have separate poles; thus, the motor is lighter and more appropriate for vertical motion applications. In addition, the proposed structure has low core losses due to the separate and short magnetic paths. The only set of windings is placed on stator poles while the translator has no winding or permanent magnet. In order to broaden the positive force region, non-uniform air-gap is designed and optimized via non-dominated sorting genetic algorithm. Finite element analysis and experimental tests of the motor are performed and characteristics of the proposed structure are compared with a previous structure in the elevator application. Finite element analysis have been done in ANSYS software.The results confirm that the proposed linear motor has higher average force with an acceptable ripple in force.
Research Articles
Power systems
Morteza Jadidoleslam; Morteza Ghaseminejad
Abstract
Wind power has been considered a future alternative to fossil energy resources. However, due to its stochastic nature, the integration of wind power plants (WPPs) into power systems poses some reliability problems such as a mismatch between load profile and efficient wind power generation. This issue ...
Read More
Wind power has been considered a future alternative to fossil energy resources. However, due to its stochastic nature, the integration of wind power plants (WPPs) into power systems poses some reliability problems such as a mismatch between load profile and efficient wind power generation. This issue can be alleviated by considering the correlation between hourly load and wind speed variations in the planning phase. To this end, a reliability-based wind power planning procedure is proposed and formulated as a stochastic programming problem. The objective function is the minimization of total costs, including capital investment, operating and maintenance, and customer energy not served costs. A new hybrid method that combines features of the load-duration curve and the K-means clustering algorithm is proposed to model the uncertainty of the input data. A shuffled frog-leaping algorithm is used to solve the proposed model. The simulation results indicate that the amount of adaptation between hours with high loads and those with high wind speeds markedly affects the selection of wind sites as optimal locations for WPP installation. Considering this issue can also improve power system reliability in the presence of WPPs.
Research Articles
Control
Mohammad Ghamgosar; Seyed Mehdi Mirhosseini-Alizamini; Mahmood Dadkhah
Abstract
This paper considers an optimal sliding mode control based on the cost control guaranteed approach using the linear quadratic regulator method to stabilize delay fractional under involved disturbance. We propose an approach to an open research problem in the design of an LMI-based sliding mode controller ...
Read More
This paper considers an optimal sliding mode control based on the cost control guaranteed approach using the linear quadratic regulator method to stabilize delay fractional under involved disturbance. We propose an approach to an open research problem in the design of an LMI-based sliding mode controller in which there are some constraints such as optimizing system performance. The sliding mode technique is well-known as an effective tool for calculating the transient response of the system and achieving robust system performance. LQR classic techniques are less effective for studying an optimal fractional system in the presence of disturbance due to nonlinearity, so we use the optimal sliding mode approach control law designed for the nominal system and, then, combined it with a fractional sliding mode controller. By using the Razumikhin theorem for the stability of fractional order systems with delay and linear matrix inequality, conditions on asymptotically stabilization were obtained . The presented controller stabilizes the nominal system and guarantees an adequate level of system performance. The sliding mode controller presented in the article, in addition to eliminating the effect of disturbance in the system, is independent of the delay A numerical example was provided to illustrate the effectiveness of the main results.
Research Articles
Power systems
Saeed Abazari; Zabihollah Faramarzi
Abstract
This study is concerned with the design of multi-input Dynamic Surface Control (DSC) to dynamic stability improvement of power systems which include both Doubly Feed Induction Generator (DFIG) and Static Synchronous Series Compensator (SSSC). The presented control method has a multi-input feature which ...
Read More
This study is concerned with the design of multi-input Dynamic Surface Control (DSC) to dynamic stability improvement of power systems which include both Doubly Feed Induction Generator (DFIG) and Static Synchronous Series Compensator (SSSC). The presented control method has a multi-input feature which acts on synchronous generators. To improve dynamic stability, the control law is developed by applying a suitable Lyapunov function. The coefficients of the proposed controller are determined by use of metaheuristic optimization algorithms. This optimal control law leads to a significantly improved performance in comparison with linear control. A particular low-pass filter is also introduced and applied to cancel the effects of additional undesired terms in the design method, leading to a simplified control form compared to the other available approaches in the literature. Implementing an adaptive parameter estimation scheme will result in the robustness of the proposed method. The effectiveness of the presented approach is investigated on a standard 39-Bus power system which includes DFIG and SSSC.
Research Articles
Control
Forough Roshanravan; Aghileh Heydari
Abstract
These days analysis and research about the nonlinear fractional system (NFS)s in the presence of uncertainty and external disturbance is one of the most critical problems in the control field. This paper investigates the asymptotic stabilization of a class of NFS while the upper bound of uncertainty ...
Read More
These days analysis and research about the nonlinear fractional system (NFS)s in the presence of uncertainty and external disturbance is one of the most critical problems in the control field. This paper investigates the asymptotic stabilization of a class of NFS while the upper bound of uncertainty and external disturbance are unknown. To do this, first, a fractional-integral sliding surface is constructed. After that, a new robust adaptive fractional sliding mode controller (RAFSMC) is designed, which is robust against the model uncertainties and external disturbances. The unknown upper bound of uncertainties and disturbances is estimated by a stable adaptive law. The Lyapunov stability theorem is used for stability analysis of the designed controller. Finally, the proposed method is applied to two practical examples, the glucose-insulin and the Lu systems. The simulation results are provided to show the effectiveness of the proposed methodology. These examples show rapid convergence to the equilibrium point with low chattering.
Research Articles
Industrial Electronics
Gholamreza Mohebalizadeh; Hasan Alipour; Leila Mohammadian; Mehran Sabahi
Abstract
To overcome the low output voltage of Renewable Energy Sources (RESs) such as photovoltaic arrays (PVAs) and fuel cells, a new multi-input DC/DC converter is presented in this paper. This converter is based on a combination of modified quadratic buck-boost converters, Switched Inductors (SIs), and Voltage ...
Read More
To overcome the low output voltage of Renewable Energy Sources (RESs) such as photovoltaic arrays (PVAs) and fuel cells, a new multi-input DC/DC converter is presented in this paper. This converter is based on a combination of modified quadratic buck-boost converters, Switched Inductors (SIs), and Voltage Multiplier Modules (VMMs). The high voltage gain can be achieved by adjusting the duty cycle and turn ratio of the coupled inductor of VMM. This structure inherits all the advantages of the SEPIC converter and using a bidirectional input port (in which an Energy Storage System (ESS) can be connected) and several unidirectional input ports. The load power can be flexibly divided among various power sources. Due to the buck-boost characteristics of the presented converter, it is suitable to charge-discharge the ESS. A Coupled Inductor (CI) is used to couple energy from input to the output equipped with the VMM. Moreover, the use of SI reduces the rise time and ripple of the input current. The stability of the proposed converter against momentary changes of VPV and Ro is the main advantage of this converter. Moreover, considering a secondary ESS as Vi instead of PV allows the converter to be active 24 hours a day. In this converter, the use of two ESSs guarantees the supply of the required output power. In addition, two bidirectional input ports prepare the ESSs charging and discharging capabilities. To verify the analysis and feasibilities of the proposed converter, simulation results are presented.
