There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Thyristor-Based FACTS Controllers for Electrical Transmission Systems

Distributed generation system operate with grid in islanding condition will damage equipment,affect the safe and stable operation of power system,even threaten the safety of line maintenance peopleTherefore,studying on distributed generation system in islanding condition has practical significanceThis paper presents an overview of islanding detection methods for distributed generation systemsThe paper classifies islanding detection methodsFinally,its study direction in the future is also looked ahead

Review of islanding detection methods for distributed generation

Permanent magnet synchronous motors (PMSMs) are known as highly efficient motors and are slowly replacing induction motors in diverse industries. PMSM systems are nonlinear and consist of time-varying parameters with high-order complex dynamics. High performance applications of PMSMs require their speed controllers to provide a fast response, precise tracking, small overshoot and strong disturbance rejection ability. Sliding mode control (SMC) is well known as a robust control method for systems with parameter variations and external disturbances. This paper investigates the current status of implementation of sliding mode control speed control of PMSMs. Our aim is to highlight various designs of sliding surface and composite controller designs with SMC implementation, which purpose is to improve controller’s robustness and/or to reduce SMC chattering. SMC enhancement using fractional order sliding surface design is elaborated and verified by simulation results presented. Remarkable features as well as disadvantages of previous works are summarized. Ideas on possible future works are also discussed, which emphasize on current gaps in this area of research.

https://www.mdpi.com/1996-1073/12/9/1669/pdf

Robust Speed Control of PMSM Using Sliding Mode Control (SMC)—A Review

Abstract of paper goes here. In this section, author is supposed to include three important parts. In the first part, it talks about the purposes of writing the paper. In the second part, methodologies that are been used in paper, should be talked. Finally, in the third part, a brief overview of results should be presented. The length of abstracts is 1/20 of whole papers. Pay attention that it shouldn’t be extended from 300 words. (Font: Times New Roman 10pt) Ability of fuel cell systems to produce power is limited so it is necessary to force the system to operate in conditions which match up with fuel cell (FC) maximum power point (MPP). MPP of FC is changed with variation of its inputs and load. Therefore a MPP tracker which utilizes a maximum power point tracking (MPPT) algorithm is necessary for tracking of MPP. This paper presents a particle swarm optimization (PSO) based MPPT algorithm for tracking of Proton Exchange Membrane fuel cell MPP (PEMFC) system. In this paper, many types of PSO include simple or conventional PSO, Improved PSO (IPSO), Quantum inspired PSO (QPSO), Vector Evaluated PSO (VEPSO) and Particle Swarm Optimization with Time Varying Acceleration Coefficients (PSOTVAC) methods are used to track MPP of FC. The MPPT algorithm determine the duty cycle of the DC/DC boost converter in order to achieve MPPT. The results of the proposed methods are compared with the conventional perturbation and observation (P&O) method. The results show that the proposed methods have better characteristic and performance (fast response and high accurate) in comparison with P&O. Also among of the proposed PSO based algorithms, conventional PSO has the fast response where PSOTVAC has the more accurate than other analyzed methods.

An Intelligent, Fast and Robust Maximum Power Point Tracking for Proton Exchange Membrane Fuel Cell - TI Journals

Power systems operation becomes more important as the load demand increases all over the world. This rapid increase in load demand forces power systems to operate near critical limits due to economical and environmental constraints. The objective in power systems operation is to serve energy with acceptable voltage and frequency to consumers at minimum cost. Flexible Alternating Current Transmission Systems (FACTS) devices have been proposed to be effective for controlling power flow and regulating bus voltage in electrical power systems, resulting in an increased transfer capability, low system losses, improved stability and increased maximum loading parameters. This paper studies the important power system phenomenon and voltage stability by using continuation power flow method, so we have focused on increasing stability and maximum loadability of a system by considering the optimal location of Flexible AC Transmission Systems (FACTS) devices in power system. Identification of a suitable location for installation of (FACTS) costly device is a vital task; several criteria are to be satisfied before selecting the best location. One type of (FACTS) devices, static synchronous compensator (STATCOM) can be installed on buses and transmission lines. The main aim of this paper is to enhance voltage stability and to increase loadability by location STATCOM based on Quantum behaved Particle Swarm Optimization (QPSO) algorithm. In order to validate the usefulness of the approach suggested here is, a case study using a 24-bus power system is presented and discussed. Simulation is done with PSAT in MATLAB. Continuation Power Flow is was implemented using Newton Raphson method.

Optimal Placement of STATCOM to Voltage Stability Improvement and Reduce Power Losses by Using QPSO Algorithm

This paper focuses on detail comparison between two common control methods including Field Oriented Control (FOC) and Direct Torque Control (DTC) of the Permanent Magnet Synchronous (PMS) motor. The main characteristics of the motor such as torque, flux and speed under different operation conditions are studied and the advantages of FOC and DTC are obtained. It can be concluded that although both the DTC and FOC methods have different structures but the motor has the same behavior on the control methods. Thus, it is concluded that both the methods can be implemented as the Direct Flux Ccontrol (DFC) and can be applied as an optimized method of PMS motor control in the industry applications.

/pdf/a-detailed-comparison-between-foc-and-dtc-methods-of-a-12wyhnf3oa.pdf

A Detailed Comparison Between FOC and DTC Methods of a Permanent Magnet Synchronous Motor Drive

Ability of fuel cell systems to produce power is limited so it is necessary to force the system to operate in conditions which match up with fuel cell (FC) maximum power point (MPP). MPP of FC is changed with variation of its inputs and load. Therefore a MPP tracker which utilizes a maximum power point tracking (MPPT) algorithm is necessary for tracking of MPP.This paper presents a particle swarm optimization (PSO) based MPPT algorithm for tracking of Proton Exchange Membrane fuel cell MPP (PEMFC) system. In this paper, many types of PSO include simple or conventional PSO, Improved PSO (IPSO), Quantum inspired PSO (QPSO), Vector Evaluated PSO (VEPSO) and Particle Swarm Optimization with Time Varying Acceleration Coefficients (PSOTVAC) methods are used to track MPP of FC. The MPPT algorithm determine the duty cycle of the DC/DC boost converter in order to achieve MPPT. The results of the proposed methods are compared with the conventional perturbation and observation (P&O) method. The results show that the proposed methods have better characteristic and performance (fast response and high accurate) in comparison with P&O. Also among of the proposed PSO based algorithms, conventional PSO has the fast response where PSOTVAC has the more accurate than other analyzed methods.

An Intelligent, Fast and Robust Maximum Power Point Tracking for Proton Exchange Membrane Fuel Cell

A bunch of factors including the limited fossil resources and rising of fossil fuel price have been causes moving to create the new structure that is based on providing energy security, and protect the environment. One of the alternatives is the fuel cell (FC). Maximum power point tracker has an important role to increase the efficiency of the FC systems. One of the difficulties in maximum power point tracking methods is rapid changes in operating conditions which affects the maximum power point (MPP) of FC. The main contribution of this paper is presentation of a robust and reliable maximum power point tracking (MPPT) method for tracking of MPP of FC under fast variation of operating conditions. The proposed method is based on eagle strategy. In order to verify the accuracy of the proposed method, simulations are performed in MATLAB/SIMULINK. The proposed method is compared with perturb and observe (P&O) and fuzzy MPPT methods. The results show that eagle strategy based MPPT approach can track the MPP of fuel cell better than P&O and fuzzy MPPT. The main features of the proposed approach are high speed for duty cycle determining and high accuracy in MPP tracking of FC in the any contingency.

http://www.ije.ir/article_72486_9da3306abcaeeb4c7600a58bd503912f.pdf

Iman Soltani

Papers

An Intelligent, Fast and Robust Maximum Power Point Tracking for Proton Exchange Membrane Fuel Cell - TI Journals

Optimal Placement of STATCOM to Voltage Stability Improvement and Reduce Power Losses by Using QPSO Algorithm

A Detailed Comparison Between FOC and DTC Methods of a Permanent Magnet Synchronous Motor Drive

An Intelligent, Fast and Robust Maximum Power Point Tracking for Proton Exchange Membrane Fuel Cell

Eagle Strategy Based Maximum Power Point Tracker for Fuel Cell System