scholarly journals Improvements on the Carrier-Based Control Method for a Three-Level T-Type, Quasi-Impedance-Source Inverter

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 677 ◽  
Author(s):  
Fermín Barrero-González ◽  
Carlos Roncero-Clemente ◽  
María Isabel Milanés-Montero ◽  
Eva González-Romera ◽  
Enrique Romero-Cadaval ◽  
...  

The boost feature that characterizes Z-source and quasi-Z-source converters is usually achieved by means of a proper insertion of short-circuit states in the full DC-link. In this work, a novel pulse width modulation carrier-based strategy for a three-phase, three-level T-type, quasi-Z-source inverter is introduced, based on the addition of alternate short-circuits in the two halves of the DC-link bus. This technique achieves better performance, less electromagnetic interference, and lower harmonic distortion of the output line-to-line voltage compared to the traditional methods based on the full DC-link shoot-through. At the same time, generating the switching states is to easy implement. The proposed strategy permits the use of electronic devices with lower blocking voltage capability, thus improving converter reliability, size, and cost. The new method may be implemented in another multilevel inverter with an impedance-source network as well. A comprehensive simulation study is performed in order to validate the adopted method, with different inverter input voltages, which is taken as representative of a photovoltaic array. Comparisons are conducted with conventional strategy insertions using the same topology in order to show the improvements achieved.

2019 ◽  
Vol 16 (2) ◽  
pp. 422-427
Author(s):  
S. Karthikeyan ◽  
K. Lakshmi ◽  
S. Sivaranjani ◽  
J. Karthika ◽  
T. Nandhakumar

Multilevel inverters are mainly used in high power and medium voltage applications to reduce the required voltage rating of the power semiconductor switching devices. Nowadays multilevel inverters are also preferred for various applications regardless of the power ratings because they can essentially realize lower harmonics with lower switching frequency and lower electromagnetic interference (EMI). However, it has some disadvantages such as increased number of components, complex Pulse Width Modulation control method, and voltage balancing problem. In this paper a new topology of cascaded multilevel inverter using reduced number of switches is introduced resulting in higher output voltage levels. There era five series connected H-bridges and the DC voltage is given in the ratio n0: n: n3:2n2:10n. The output voltage having 123 levels is obtained (61 positive voltage levels, 61 negative voltage levels and zero voltage levels). Reduced Total Harmonic Distortion (THD) makes them useful for electric vehicle, FACTS and has given option for various power applications. The proposed topology results in reduction of cost and has simplicity of control system. Therefore, the overall cost and complexity are greatly reduced particularly for higher output voltage levels.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xiangshun Li ◽  
Jianghua Lu

A novel control method is proposed for the three-phase four-wire four-leg active power filter (APF) to realize the accurate and real-time compensation of harmonic of power system, which combines space vector pulse width modulation (SVPWM) with triangle modulation strategy. Firstly, the basic principle of the APF is briefly described. Then the harmonic and reactive currents are derived by the instantaneous reactive power theory. Finally simulation and experiment are built to verify the validity and effectiveness of the proposed method. The simulation results show that the response time for compensation is about 0.025 sec and the total harmonic distortion (THD) of the source current of phaseAis reduced from 33.38% before compensation to 3.05% with APF.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 282
Author(s):  
Seon-Ik Hwang ◽  
Jang-Mok Kim

The common-mode voltage (CMV) generated by the switching operation of the pulse width modulation (PWM) inverter leads to bearing failure and electromagnetic interference (EMI) noises. To reduce the CMV, it is necessary to reduce the magnitude of dv/dt and change the frequency of the CMV. In this paper, the range of the CMV is reduced by using opposite triangle carrier for ABC and XYZ winding group, and the change in frequency in the CMV is reduced by equalizing the dwell time of the zero voltage vector on ABC and XYZ winding group of dual three phase motor.


2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.


2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.


2021 ◽  
Author(s):  
Christel E. G. Ogoulola ◽  
Angelo J. J. Rezek ◽  
Robson B. Gonzatti ◽  
Vinicius Z. Silva ◽  
Marcos L. Ramos ◽  
...  

This paper deals with the theoretical development, analysis, and simulation of the new topology of three-phase NPC (Neural Point Clamped) converter. The proposed 6-kW three-phase converter is connected to a three-phase electrical network and due to its bidirectional characteristics can either send energy to the grid or receive it from the grid. The classic strategy of vectorial control at the DQ synchronous reference frame, along with a simple algorithm for Unit Vector Generation (UVG), have been employed to control the line currents in the grid and the DC-bus voltage, thus substituting the PLL (Phase Locked Loop). A PWM (Pulse Width Modulation) strategy is presented in the form of an analog circuit and used for switching the semiconductors in the converter. The obtained results were verified using Matlab/Simulink software. The proposed converter has five voltage levels at the output for each phase and proven more advantageous than the conventional NPC. In addition, it was obtained a better harmonic content in the grid currents because there is very low Total Harmonic Distortion (THD) both when acting as a rectifier and as an inverter.


Author(s):  
J. Lamterkati ◽  
L. Ouboubker ◽  
M. Khafallah ◽  
A. El afia

<p><span>The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.</span></p>


2021 ◽  
pp. 74-83
Author(s):  
YURI D. VOLCHKOV ◽  

Abstract. The load current aff ects the value of the short-circuit current in the electric network and, consequently, the voltage value. In some cases, this infl uence must be taken into account for the correct choice of switching devices, remote monitoring the operating modes of electric networks, and determining the modes. It is possible to disconnect loads connected through magnetic starters and contactors. Failure to consider the infl uence of the load current can lead to an incorrect interpretation of the identifi ed grid operating modes during remote monitoring and, as a result, incorrect dispatcher’s decisions. In addition, it is also insuffi cient to specify the choice of switching devices in the 10 kV feed network. The article describes a method for analyzing the three-phase short circuit mode in a 10 kV feed network, taking into account the infl uence of load currents. The method is exemplifi ed by the case of an actual electric network – the 10 kV ring feed network containing reclosers and receiving power from diff erent sections of lowvoltage buses of the “Kulikovskaya” 110/35/10 kV substation, belonging to the Branch of PJSC «DGC of Center”-“Orelenergo.” For this network, the values of the three-phase short-circuit currents at points with diff erent distances from the substation buses have been determined. The authors have fi guredout the values of the load currents and their shares in the total short-circuit current. The voltage values at different points of the network in the case of short circuits have also been determined. The research proves that the effect of the load current on the total short-circuit current should be taken into account for the case of remote short circuits.


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 296 ◽  
Author(s):  
Van-Thuan Tran ◽  
Minh-Khai Nguyen ◽  
Cao-Cuong Ngo ◽  
Youn-Ok Choi

This paper presents a three-phase cascaded five-level H-bridge quasi-switched boost inverter (CHB-qSBI). The merits of the CHB-qSBI are as follows: single-stage conversion, shoot-through immunity, buck-boost voltage, and reduced passive components. Furthermore, a PWM control method is applied to the CHB-qSBI topology to improve the modulation index. The voltage stress across power semiconductor devices and the capacitor are significantly lower using improved pulse-width modulation (PWM) control. Additionally, by controlling individual shoot-through duty cycle, the DC-link voltage of each module can achieve the same values. As a result, the imbalance problem of the DC-link voltage can be solved. A detailed analysis and operating principle with the modulation scheme and comprehensive comparison for the CHB-qSBI are illustrated. The experimental and simulation results are presented to validate the operating principle of the three-phase CHB-qSBI.


Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 234 ◽  
Author(s):  
Ahmet Aksoz ◽  
Yipeng Song ◽  
Ali Saygin ◽  
Frede Blaabjerg ◽  
Pooya Davari

In this paper, a virtual positive impedance (VPI) based active damping control for a slim DC-link motor drive with 24 section space vector pulse width modulation (SVPWM) is proposed. Utilizing the proposed control and modulation strategy can improve the input of current total harmonic distortion (THD) while maintaining the cogging torque of the motor. The proposed system is expected to reduce the front-end current THD according to international standards, as per IEC 61000 and IEEE-519. It is also expected to achieve lower cost, longer lifetime, and fewer losses. A permanent magnet synchronous motor (PMSM) is fed by the inverter, which adopts the 24 section SVPWM technique. The VPI based active damping control for the slim DC-link drive with/without the 24 section SVPWM are compared to confirm the performance of the proposed method. The simulation results based on MATLAB are provided to validate the proposed control strategy.


Sign in / Sign up

Export Citation Format

Share Document