scholarly journals A Hybrid Control Scheme with Fast Transient and Low Harmonic for Boost PFC Converter

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1848
Author(s):  
Sen-Tung Wu ◽  
Fu-Yuan Chen ◽  
Min-Chu Chien ◽  
Jian-Min Wang ◽  
Yan-Ying Su
Keyword(s):  
Control Strategy ◽  
Feedforward Control ◽  
Harmonic Distortion ◽  
Dynamic Responses ◽  
Input Current ◽  
Direct Reading ◽  
Peak Voltage ◽  
Current Harmonic ◽  
Control Loops ◽  
Control Circuits

In this study, a new control strategy was proposed to improve transient response and the input current harmonic distortion of power factor correction (PFC) regulators operating in an average current mode. The proposed technique required only two additional gain selectors and a peak detector circuit on the feedforward voltage loop and output voltage feedback loops. It provided a direct reading for the average voltage value of feedback control loops and the peak voltage of feedforward control loops, producing PFC boost regulators with fast dynamic responses and low-input current harmonic distortion. The use of digital potentiometers for directly changing the gain of control loops did not require any divider or squarer to reduce the complexity of control circuits. The operating principles and control strategies of 300 W boost PFC with the new control strategy are presented with detailed analysis and discussion. The experimental results were satisfactory.

Perfectly Matched Feedback Control and Its Integrated Design for Multiaxis Motion Systems

2004 ◽  
Vol 126 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Syh-Shiuh Yeh ◽  
Pau-Lo Hsu
Keyword(s):  
Feedback Control ◽  
High Speed ◽  
Feedforward Control ◽  
Phase Error ◽  
Integrated Design ◽  
Cnc Machining ◽  
Dynamic Responses ◽  
Tracking Accuracy ◽  
Control Loops ◽  
Contouring Accuracy

For motion systems with multiple axes, the approach of matched direct current gains has been generally adopted to improve contouring accuracy under low-speed operations. To achieve high-speed and high-precision motion in modern manufacturing, a perfectly matched feedback control (PMFBC) design for multiaxis motion systems is proposed in this paper. By applying stable pole-zero cancellation and including complementary zeros for uncancelled zeros for all axes, matched dynamic responses across the whole frequency range for all axes are achieved. Thus, contouring accuracy for multiaxis systems is guaranteed for the basic feedback loops. In real applications, the modeling error is unavoidable and the degradation and limitations of the model-based PMFBC exist. Therefore, a newly designed digital disturbance observer is proposed to be included in the proposed PMFBC structure for each axis to compensate for undesirable nonlinearity and disturbances to maintain the matched dynamics among all axes for the PMFBC design. Furthermore, the feedforward control loops zero phase error tracking controller are employed to reduce tracking errors. Experimental results on a three-axis CNC machining center indicate that both contouring accuracy and tracking accuracy are achieved by applying the present PMFBC design.

Improved Control Strategy for Voltage and Current Compensator in a Grid-Connected Microgrid Without Dedicated Devices

2020 ◽  
Vol 17 (2) ◽  
pp. 1099-1105
Author(s):  
Attaullah Khidrani ◽  
M. H. Habibuddin ◽  
A. S. B. Mokhtar ◽  
A. H. Sule ◽  
A. Naderipur ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Control Strategy ◽  
Harmonic Distortion ◽  
Operating Conditions ◽  
Current Harmonic ◽  
Linear Load ◽  
Three Phase ◽  
Passive Filters ◽  
Combined Control ◽  
Non Linear Load

This paper proposes the combined control strategy to suppress the voltage and current harmonic contents in a three-phase hybrid fuel cell and wind turbine grid-connected inverters when subjected to non-linear load and unbalanced conditions. This innovative technique can effectively reduce the harmonic contents in the voltage and current of the studied system without any dependence on offset devices such as active and passive filters. The microgrid along with the proposed controlled strategy is modeled in Matlab/Simulink environment. In this research, it shows that the proposed control strategy not only reduces the total harmonic distortion (THD) to less than 5% (as compliance with IEEE 519 standard). It shows the superiority performance in the result as compared to existing techniques with the stabilization of unbalancing condition under different operating conditions with load changes and instant DG insertion.

Efficiency Optimized Brushless DC Motor Drive based on Input Current Harmonic Elimination

2015 ◽  
Vol 6 (4) ◽  
pp. 869
Author(s):  
Tridibesh Nag ◽  
Arijit Acharya ◽  
Debashis Chatterjee ◽  
Ashoke Kumar Ganguli ◽  
Arunava Chatterjee
Keyword(s):  
Harmonic Distortion ◽  
Input Current ◽  
Brushless Dc Motor ◽  
Motor Drive ◽  
Efficiency Improvement ◽  
Current Harmonic ◽  
Brushless Dc ◽  
Harmonic Elimination ◽  
Selective Harmonic Elimination ◽  
Core Losses

<p>This paper describes efficiency improvement of a position sensorless brushless DC (BLDC) motor with improved PWM scheme for the inverter compared to existing ones. This is based on Selective Harmonic Elimination (SHE). The proposed method reduces total harmonic distortion (THD) from the input current and armature flux and thereby reducing the core losses. The effectiveness of the proposed scheme is demonstrated through simulation and experimental results.</p>

scholarly journals Experimental Evaluation on the Influence of RCD Snubbers in a 3-Level Thyristor Based MLCR CSC

2016 ◽  
Vol 2016 ◽  
pp. 1-18
Author(s):  
Bhaba P. Das ◽  
Neville R. Watson ◽  
Yonghe Liu
Keyword(s):  
Experimental Evaluation ◽  
Output Voltage ◽  
Current Source ◽  
Harmonic Distortion ◽  
Experimental Results ◽  
Input Current ◽  
Trade Off ◽  
Current Harmonic ◽  
Line Current ◽  
Snubber Circuit

Multilevel current reinjection (MLCR) concept provides self-commutation capability to thyristors, enabling thyristor based current source converters (CSC) to operate under negative firing angle. It also lowers the input current harmonic distortion. This is achieved by using an auxiliary reinjection bridge. Extensive experimental results are presented in this paper to analyse the performance of the 3-level MLCR CSC for different snubber components across the reinjection bridge. The trade-off in the choice of the snubber circuit is illustrated, with its influence on the AC side line current and DC side output voltage of the 3-level MLCR CSC.

scholarly journals Evaluation of Process Control Schemes for Sour Water Strippers in Petroleum Refining

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 363
Author(s):  
Chii-Dong Ho ◽  
Yih-Hang Chen ◽  
Chao-Min Chang ◽  
Hsuan Chang
Keyword(s):  
Feedback Control ◽  
Prediction Models ◽  
Feedforward Control ◽  
Absolute Error ◽  
Dynamic Responses ◽  
Control Schemes ◽  
Online Measurements ◽  
Measurement Delay ◽  
Water Feed ◽  
Sour Water

For the sour water strippers in petroleum refinery plants, three prediction models were developed first, including the estimators of sour water feed concentrations using convenient online measurements, the minimum reboiler duty and the corresponding internal temperature at a specific location (Tstage,29). Feedforward control schemes were developed based on these prediction models. Four categories of control schemes, including feedforward, feedback, feedback with external reset, and feedforward-feedback, were proposed and evaluated by the rigorous dynamic simulation model of the sour water stripper for their dynamic responses to the sour water feed stream disturbances. The comparison of control performance, in terms of the settling time, integrated absolute error (IAE) of the NH3 concentration of the stripped sour water and IAE of the specific reboiler duty, reveals that FFT (feedforward control of Tstage,29) and FBA-DT3 (feedback control with 3 min concentration measurement delay) are the best control schemes. The second-best control scheme is FBAT (cascade feedback control of concentration with temperature).

scholarly journals Fault-Tolerant Control Strategy with Asymmetric Phase Currents for Single to Four-Phase Open-Circuit Faults of Six-Phase PMSM

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3163
Author(s):  
Chen Huang ◽  
Lidan Zhou ◽  
Zujia Cao ◽  
Gang Yao
Keyword(s):  
Working Conditions ◽  
Control Strategy ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Open Circuit ◽  
Time Varying ◽  
Electromagnetic Torque ◽  
Control Loops ◽  
Phase Current ◽  
Multi Phase

Multi-phase motors and generators are regarded with great fault tolerance capability, especially on open-circuit faults. Various mathematics analytical methods are applied for their fault control. In this paper, a fault-tolerant control strategy with asymmetric phase current for the open-circuit faults with arbitrary phases in the six-phase PMSM (six-phase permanent magnetic synchronous motor, 6P-PMSM) system, is proposed for better electrical and dynamical performance of the machine. An innovative mathematical model for PMSM under one to four-phase-open circuit faults are established considering the asymmetry of the machine. Combining with time-varying relations in machines’ working conditions, targeted decoupling transformation matrixes of every kind of open-circuit faults are settled by voltage equations under different faults. Modified control strategy with a connection between the neutral point and the inverter’s DC side is presented, which aims at increasing the system redundancy and reducing the amplitude of phase currents. Besides, improved control loops with two layers are put forward as well, with which the PMSM system acquires fewer harmonics in phase current and smoother electromagnetic torque. Simulation and experimental results of open-circuit faults are provided for verification of the theoretical analysis.

PI and Fuzzy-Controlled 3-Phase 4-Wire Interleaved Buck Active Power Filter with Shoot-Through Elimination for Power Quality Improvement using RTDS Hardware

2014 ◽  
Vol 15 (2) ◽  
pp. 177-194 ◽  
Author(s):  
Anup Kumar Panda ◽  
Ranjeeta Patel
Keyword(s):  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Active Power Filter ◽  
Active Power ◽  
Current Harmonics ◽  
Power Filter ◽  
Power Quality Improvement ◽  
Real Time Digital Simulator

Abstract In this paper, shoot-through current elimination DC–AC converter circuit has been presented with the application of active power filter (APF). The intuitive analysis of the shoot-through in the conventional DC–AC converter has been reported first. Interleaved buck (IB) converter is adopted to eliminate the shoot-through current, thereby increasing the reliability of the interleaved buck–based active power filter (IB-APF). The 3-phase 4-wire IB-APF eliminates the current harmonics produced by the load just as a conventional one does and are innately immune to “shoot-through” phenomenon, with the elimination of special protection features required in conventional inverter circuits. A comparison has been made about the compensation capabilities of the IB-APF with the PI and fuzzy logic controller (FLC) used by id–iq control strategy under different supply voltage conditions. The id–iq control strategy used for extracting the three-phase reference current for IB-APF, evaluating their performance here in MATLAB/Simulink environment and also implemented using real-time digital simulator hardware (OPAL-RT hardware). The RTDS result verifies that the total harmonic distortion percentage of the source current can be reduced below 5% according to IEEE-519 standard recommendations on harmonic limits.

An internal parallel capacitor control strategy for DC-link voltage stabilization of PMSG-based wind turbine under various fault conditions

2021 ◽  
pp. 0309524X2110606
Author(s):  
Mohamed Metwally Mahmoud ◽  
Mohamed M Aly ◽  
Hossam S Salama ◽  
Abdel-Moamen M Abdel-Rahim
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Control Strategy ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
Synchronous Generator ◽  
Parallel Capacitor ◽  
Wind Generators ◽  
Fast Fourier Transform Analysis ◽  
Energy Conversion Systems

In recent years, wind energy conversion systems (WECSs) have been growing rapidly. Due to various advantages, a permanent magnet synchronous generator (PMSG) is an appealing solution among different types of wind generators. As wind power penetration level in the grid increases, wind power impacts the grid and vice versa. The most essential concerns in the system are voltage sag and swell, and grid code compliance, particularly for low voltage ride-through (LVRT) and high voltage ride-through (HVRT) capability, is a pressing necessity. This paper presents a parallel capacitor (PC) control strategy to enhance the LVRT and HVRT capability of PMSG. Furthermore, this study presents a method for the sizing of a PC system for the reduction of the overvoltage of the DC-link during voltage sags and swell. Fast Fourier transform analysis is used to determine the total harmonic distortion (THD) for the injected current into the grid. The obtained results illustrate the effectiveness of the proposed system in keeping the DC-link voltage below the limit, power quality improvement, and increasing the LVRT and HVRT capability. Models of wind turbine, PMSG, and PC control system are built using MATLAB/SIMULINK software.

Study of the Influence of Control System Parameters on the Quality of the Input Current of a Three-Phase Power Factor Corrector

2021 ◽  
Vol 2 (2) ◽  
pp. 29-35
Author(s):  
Dmitry A. Sorokin ◽  
◽  
Sergey I. Volskiy ◽  
Jaroslav Dragoun ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Power Factor ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Input Current ◽  
System Operation ◽  
Error Amplifier ◽  
Three Phase ◽  
Power Factor Corrector

The paper suggests a control system of a three-phase power factor corrector. The study of the control system operation is carried out and the expressions for calculating the permissible values of error amplifier factors are obtained. The influence of the error amplifier parameters on phase current quality is investigated. The dependence of total harmonic distortion input current on a combination of error amplifier parameters is obtained at a given value of power factor. The conditions under which the total harmonic distortion input current has the minimum value are found out. This article is of interest to power electronics engineers, who are aimed at developing a three-phase power factor corrector.

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