Original Article
Alireza Rahimi; Khalil Kanzi
Abstract
In this paper, a physics-based analytical method is proposed in order to model the frequency behavior of laminated iron-core permanent magnet synchronous motor (PMSM). The proposed model consists of frequency-dependent lumped circuit parameters representing two parts; Iron-core and stator winding. These ...
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In this paper, a physics-based analytical method is proposed in order to model the frequency behavior of laminated iron-core permanent magnet synchronous motor (PMSM). The proposed model consists of frequency-dependent lumped circuit parameters representing two parts; Iron-core and stator winding. These frequency-dependent components represent the skin effect and proximity effect in conductors and eddy-currents effect in the core. The total parasitic capacitance is considered to be frequency-independent and estimated from measured impedance characteristics of the PMSM. In order to verify the accuracy of the proposed model, we compared the equivalent AC resistance and AC inductance of one phase of a counter-rotating PMSM calculated from the proposed analytical method with the 3D finite element analysis (FEA) results. Finally, the Impedance characteristic of the test PMSM calculated using the proposed method is verified by the impedance measurement data, which shows a good agreement. The method proposed in this paper can be used for modeling various high-frequency issues in variable speed drives (VSDs) such as electromagnetic interference (EMI), common-mode bearing currents, and long-cable effects on motor terminals.
Original Article
Ali Asghar Sarabadani; reza latifi; ali reza rezazadeh
Abstract
The increasing growth of the technology and industry of electric propulsion, and consequently the growth of the industry of electric energy storage systems, including batteries, have raised challenges such as optimizing the charging process and storage of electric energy. One of the important factors ...
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The increasing growth of the technology and industry of electric propulsion, and consequently the growth of the industry of electric energy storage systems, including batteries, have raised challenges such as optimizing the charging process and storage of electric energy. One of the important factors in optimizing the charging process is reducing the time interval. Hence, today, topologies such as fast charging and stations equipped with this topologies are expanding. Quick charging topologies reduce the length of the charging process by optimizing the electric charge circuit and optimizing the design of switching elements and its control system. This paper first examines the electric vehicle charging system in terms of the standards that classify the input voltage level as well as the technologies that increase the flexibility and efficiency of the electric vehicle charging system. Technologies such as unidirectional and bi-directional charging system, inductive and conductive charging system, integrated and non-integrated systems are presented and discussed in this article. In the second step, these systems are transformed into switching components and features such as the possibility of development with renewable energy production systems, the possibility of injecting power from the electric vehicle energy storage system into the power grid to provide part of the power required at peak demand and also The complexity and multiplicity of key elements have been examined and compared.
Original Article
Hossein Azizi Moghadam; Masood Saeidi; Abolfazl Vahedi; omid Rezaei; Shervin Salehirad
Abstract
synchronous reluctance motors are among the most popular electric motors today, due to their relatively good features, but the important thing to consider about these motors is to calculate and estimate their rotor position, and failure to do so may cause damage in their control system. Therefore, many ...
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synchronous reluctance motors are among the most popular electric motors today, due to their relatively good features, but the important thing to consider about these motors is to calculate and estimate their rotor position, and failure to do so may cause damage in their control system. Therefore, many methods such as sensorless, hall-effect, GMR, encoder, etc. were used to compute and estimate the rotor position, each of which has its own advantages and disadvantages. Besides, in many articles, the effect of positional error and the effect of this error on the control system and the method of dealing with this chronic problem are not analytically stated, and only this phenomenon has been studied in operation. Whereas, in this paper, firstly, a variety of conventional methods available for estimating and calculation the rotor position of synchronous reluctance motors briefly is introduced, and then investigated the effect of the error on the control system and at the end, the results of simulation and mathematical analyzes the impact of this error on the control system is presented.
Original Article
Mahmudreza Changizian; abbas Shoulaie
Abstract
Abstract—The starting-up strategy is an important issue for voltage source convert-high voltage direct current (VSC-HVDC) system. If a VSC-HVDC system starts up without any auxiliary system or improved control system, overvoltage and inrush current will occur. This large overvoltage can cause serious ...
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Abstract—The starting-up strategy is an important issue for voltage source convert-high voltage direct current (VSC-HVDC) system. If a VSC-HVDC system starts up without any auxiliary system or improved control system, overvoltage and inrush current will occur. This large overvoltage can cause serious damage on the DC capacitors and this large inrush current at turn-on may destroy the switches in converter. Starting-up VSC-HVDC has two steps. In this paper, starting-up steps in a three-phase two-level VSC-HVDC system is studied with details. The effect of capacitor and inductor sizes and also circuit breaker closing time on overvoltage and inrush current in first step are investigated attentively. Possible methods for control overvoltage and inrush currents during this step are presented, and a comparison has been made between them in terms of power dissipation and cost. Eventually, the best auxiliary starting-up system is selected in terms of costs. In addition, the second step of starting-up is also examined and the circuit performance for increasing the DC link voltage is described in this step. Also, a simple control method is proposed for controlling the inrush current in second step. This method controls the inrush current without imposing additional costs and losses on the system. Substantial simulations conducted on PSCAD/EMTDC platform. It is worth mentioning this paper is an extended version of the paper accepted at the 34th Power System Conference (PSC 2019).
Original Article
Ali Asghar Sarabadani; Hamid Reza Bagheri; Ali Reza Rezazadeh
Abstract
Using hybrid renewable energy is one of the best alternatives to supply the electrical energy at remote areas. Renewable energy sources are depended to weather conditions or other factors, so for supplying load with renewable sources appropriate capacity of these sources should be selected. In determining ...
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Using hybrid renewable energy is one of the best alternatives to supply the electrical energy at remote areas. Renewable energy sources are depended to weather conditions or other factors, so for supplying load with renewable sources appropriate capacity of these sources should be selected. In determining the capacity of renewable energy such as wind and solar, considering the stochastic nature of wind speed and solar radiation is very impressive.one of the problems of using energies like Wind and PV in micro-grid is their Intrinsic uncertainty and their random stochastic which made programming and predicting of such resources complicated. In this Project, stochastic programming and probability scenarios are used in order to model uncertainty in both Wind and PV resources. Optimum programming of micro-grid which is connected to the main grid is considered by mixed integer programming in Gams software in which Virtual Power Producer manages optimum producing and load control by using main control system.In order to solve the economic distribution of power in a micro-grid with different constraints, such as load and generation balancing, generation constraints, charging of storage resources in different scenarios and also the issue of unit commitment for sources of generation, the mixed integrated programming approach in this paper has been used.
Original Article
Arta Mohammad-Alikhani; Abolfazl Vahedi; Farshid Mahmouditabar; Mehdi Rahnama
Abstract
Permanent magnet synchronous motors (PMSMs) have rencently attracted much attention of scientists due to high reliability, high efficiency, high density of power and torque. However, Permanent magnet (PM) motros suffer from irreversible demagnetization which is one of the most probable problems occurring ...
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Permanent magnet synchronous motors (PMSMs) have rencently attracted much attention of scientists due to high reliability, high efficiency, high density of power and torque. However, Permanent magnet (PM) motros suffer from irreversible demagnetization which is one of the most probable problems occurring in these motors. One of the recently developed permanent magnet synchronous motors, is the Flux Switching Permanent Magnet (FSPM) motor whose PM is placed on the stator. In this paper, a novel approach is proposed for the diagnosis of the demagnetization fault in a flux switching permanent magnet motor using electromagnetic torque. In this approach, the harmonic components of the electromagnetic torque are obtained, and then, ReliefF feature selection method is utilized to select the best-ranked harmonic component. The selected harmonic component is then applied to the Support Vector Machine (SVM) classifier to classify different states of the motor’s PM. The proposed approach is validated by Finite Element Model (FEM) simulation.
Original Article
Arsalan Hekmati; iman sadeghi
Abstract
Synchronous speeds in all types of alternating current machines depend on the frequency of the power grid, and performance at higher speeds at steady conditions requires higher frequency feeds. The development of speed control drive technology in recent decades has prompted renewed attention to high-speed ...
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Synchronous speeds in all types of alternating current machines depend on the frequency of the power grid, and performance at higher speeds at steady conditions requires higher frequency feeds. The development of speed control drive technology in recent decades has prompted renewed attention to high-speed engines. Important advantages of using high speed electric motors include higher density (and smaller dimensions) and greater torque generation capability. Also, the use of these motors enables the removal of the gearbox and lubrication system, which reduces maintenance costs. Nowadays, surface-mounted PMSMs are increasingly used for high-speed applications, because of the merits of simple structure and high-strength of the rotor. This paper first discusses the fundamental differences in the configurations of ordinary and high-speed permanent magnet motors, considering their specific characteristics. The specimens and their properties, have been discussed. Finally, the modern applications of high-speed permanent magnet motors have been introduced. also, the main manufacturers of high speed synchronous motors have been presented.
Original Article
ali mosallanejad
Abstract
Abstract: This paper presents a novel passive approach for islanding detection of wind turbines. Islanding is such a condition which the DG get disconnected from the utility because of disturbances in the network. Islanding can create many problems in power systems and existing standards thus do not ...
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Abstract: This paper presents a novel passive approach for islanding detection of wind turbines. Islanding is such a condition which the DG get disconnected from the utility because of disturbances in the network. Islanding can create many problems in power systems and existing standards thus do not permit the DGs to be utilized in island mode. Some of the major problems that can happen in island mode are: disruption in the protection network, over load conditions of DG, out of phase connection of DG to the network, decrement of the customer’s power quality, safety hazards for personnel, DG over loads and etc. The proposed method in this paper is based on the voltage signal that is measured in point of common coupling (PCC) and processing this voltage with mathematical morphology (MM). In comparison with other methods, this method is so fast. The simulations of this paper is based on Matlab/Simulink and the feasibility of the proposed technique is evaluated with that simulations. The results of the evaluation and comparison with other methods approves the feasible performance and higher speed of the proposed method.
Original Article
pouria maghouli; Mohamad Saleh Shajarehpour
Abstract
Integrating Electric vehicles into distribution systems introduce new challenges both in operation and planning of electric distribution systems. In the planning process, these vehicles mainly affect load uncertainty in the grid. A new method for Active Distribution Network (ADN) expansion planning is ...
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Integrating Electric vehicles into distribution systems introduce new challenges both in operation and planning of electric distribution systems. In the planning process, these vehicles mainly affect load uncertainty in the grid. A new method for Active Distribution Network (ADN) expansion planning is proposed considering the uncertainty of bus loadings because of electric vehicles (EVs) integration. The approach taken in this paper includes the initial cost of investment and operation. A probabilistic model is proposed for extracting the effect of electric vehicles integration on future loading of network buses. Different scenarios are defined based on electric vehicle entrance time, charging delays and their overall penetration level. Particles colony algorithm is used for handling the proposed mixed integer and nonlinear optimization model. Also, a graph theory based method for detecting radial structures is implemented for faster convergence. Finally, the effectiveness of the proposed algorithm is examined by implementing it on the modified IEEE 33 bus standard distribution network.
Original Article
َAli Asghar Sarabadani; Hamid Reza Bagheri; Ali Reza Rezazadeh
Abstract
A micro-grid usually consists of a set of distributed generation resources, a power storage system and loads that can be exploited in both grid-connected and island operations, The use of micro-grid can have many benefits for consumers and for power generator companies, from point of view of consumers ...
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A micro-grid usually consists of a set of distributed generation resources, a power storage system and loads that can be exploited in both grid-connected and island operations, The use of micro-grid can have many benefits for consumers and for power generator companies, from point of view of consumers micro-grid has the capability to simultaneously provide electricity and heat, increase reliability, reduce greenhouse gas emissions, and improve the quality of electricity and from point of view of companies The use of micro-grid will reduce the facility for the development of transmission lines and, in addition, will eliminate peak consumption points, which will also result in network losses reduction. Micro-grids can be a good solution for energy generation, considering the environmental and economic issues. In this paper, determining the economic power dispatch of a grid-connected micro-grid system by Stochastic programming is examined. The hybrid system studied consists of wind turbines, solar arrays, hydrogen fuel cells, combined heat and power storage units, the purpose is to minimize the cost of generating power and reduce the cost of environmental pollution using the genetic algorithm in the study period.
