다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

Power electronics

Thyristor-Based FACTS Controllers for Electrical Transmission Systems

This paper discusses the power quality issues for distributed generation systems based on renewable energy sources, such as solar and wind energy. A thorough discussion about the power quality issues is conducted here. This paper starts with the power quality issues, followed by discussions of basic standards. A comprehensive study of power quality in power systems, including the systems with dc and renewable sources is done in this paper. Power quality monitoring techniques and possible solutions of the power quality issues for the power systems are elaborately studied. Then, we analyze the methods of mitigation of these problems using custom power devices, such as D-STATCOM, UPQC, UPS, TVSS, DVR, etc., for micro grid systems. For renewable energy systems, STATCOM can be a potential choice due to its several advantages, whereas spinning reserve can enhance the power quality in traditional systems. At Last, we study the power quality in dc systems. Simpler arrangement and higher reliability are two main advantages of the dc systems though it faces other power quality issues, such as instability and poor detection of faults.

https://vbn.aau.dk/ws/files/294611667/08314672.pdf

Analysis and Mitigation of Power Quality Issues in Distributed Generation Systems Using Custom Power Devices

An improved residual-based convolutional neural network for very short-term wind power forecasting

Harmonics is one of the major power quality problems for power systems. The harmonics can be eliminated by power filters such as passive, active, and hybrid. In this study, a new passive filter configuration has been improved in addition to the existing passive filter configurations. Conventional hybrid passive filters are not successful to compensate rapidly changing reactive power demand. The proposed configure are capable of compensating both harmonics and reactive power at the same time. Simulation results show that performance of reactive power and harmonic compensation with advanced hybrid passive filter is better than conventional hybrid passive filters.

/pdf/advanced-configuration-of-hybrid-passive-filter-for-reactive-2upyvmv329.pdf

Advanced configuration of hybrid passive filter for reactive power and harmonic compensation

Original scientific paper It is well-known that shunt active power filter (SAPF) is widely used to reduce harmonic distortion and to compensate reactive power in electrical power systems. DC bus voltage control of SAPF is very important for excellent power quality. In the control of SAPF, DC bus voltage is controlled by conventional control methods such as PI and PID controllers. However, these controllers cannot give good results under transient and steady state conditions. Robust and intelligent controllers are required in order to improve performance of SAPF. In this paper, interval type-2 fuzzy logic system (T2FLS) that does not require mathematical model to be controlled system is preferred for control of DC bus voltage of SAPF and compared with type-1 fuzzy logic system (T1FLS). SAPF structures with both controllers are designed and simulated using MATLAB /Simulink environment. Simulation results have shown that SAPF structure with proposed controller has superior features than T1FLS in terms of fixed DC bus voltage, total harmonic distortion and power quality.

Robust control of shunt active power filter using interval type-2 fuzzy logic controller for power quality improvement

In this study, comparison between PI controller, fuzzy logic controller (FLC) and an anti-windup PI (PI+AW) controller used for speed control with direct torque controlled induction motor is presented. Direct torque controlled induction motor drive system is implemented in MATLAB/Simulink environment and the FLC is developed using MATLAB/Fuzzy-Logic toolbox. The proposed control strategy is performed different operating conditions. Simulation results, obtained from PI controller, FLC and PI+AW controller showing the performance of the closed loop control systems, are illustrated in the paper. Simulation results show that FLC is more robust than PI and PI+AW controller against parameter variations and FLC gives better performance in terms of rise time, maximum peak overshoot and settling time.

https://www.ijisae.org/IJISAE/article/download/105/68

Speed Control of Direct Torque Controlled Induction Motor By using PI, Anti-Windup PI And Fuzzy Logic Controller

In recent years, electronic power transformer (EPT), which is also called solid state transformer, has attracted great interest and has been used in place of the conventional power transformers. These transformers have many important functions as high unity power factor, low harmonic distortion, constant DC bus voltage, regulated output voltage and compensation capability. In this study, proposed EPT structure contains a three-phase pulse width modulation rectifier that converts 800 Vrms AC to 2000 V DC bus at input stage, a dual active bridge converter that provides 400 V DC bus with 5:1 high frequency transformer at isolation stage and a three-phase two level inverter that is used to obtain AC output at output stage. In order to enhance dynamic performance of EPT structure, neuro fuzzy controllers which have durable and nonlinear nature are used in input and isolation stages instead of PI controllers. The main aim of EPT structure with the proposed controller is to improve the stability of power system and to provide faster response against disturbances. Moreover, a number of simulation results are carried out to verify EPT structure designed in MATLAB/Simulink environment and to analyze compensation ability for voltage harmonics, voltage flicker and voltage sag/swell conditions.

/pdf/performance-analysis-of-electronic-power-transformer-based-46lt17kh5h.pdf

Mustafa Şekkeli

Papers

Advanced configuration of hybrid passive filter for reactive power and harmonic compensation

Robust control of shunt active power filter using interval type-2 fuzzy logic controller for power quality improvement

Speed Control of Direct Torque Controlled Induction Motor By using PI, Anti-Windup PI And Fuzzy Logic Controller

Performance analysis of electronic power transformer based on neuro-fuzzy controller

Development of a novel method for optimal use of a newly designed reactive power control relay