Continuous PWM Modulation Strategy for NPC/H and H Bridge Hybrid Multilevel Converter

2013 ◽  
Vol 748 ◽  
pp. 510-513
Author(s):  
Hong Zheng ◽  
Yue Lei Shi ◽  
Hang Hui Zhang
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
Supply Voltage ◽  
Matlab Simulation ◽  
Multilevel Converter ◽  
Multilevel Converters ◽  
Voltage Variation ◽  
Slave Converter ◽  
And Control

f the ratio of NPC/H and H bridge hybrid multilevel converters DC supply voltage changed, the output voltage PWM waveform will be discontinuous. Thus an improved topology and control strategy is proposed. In new method, master converter operates at the fundamental frequency based on command voltage, slave converter adopts carrier phase shifted PWM technology (CPS-SPWM) at a higher frequency to enhance the quality of output voltage waveform. The amplitude of command voltage is higher than output voltage amplitude of the master converter at any time, to ensure that output voltage variation of both converters keeps in the same direction without any current flow backwards. Matlab simulation results demonstrate the effectiveness of the proposed control strategy and topology.

The Research of Air Precooling System Based on Generalize Predictive Control Strategy

2013 ◽  
Vol 433-435 ◽  
pp. 1091-1098
Author(s):  
Wei Bo Yu ◽  
Cui Yuan Feng ◽  
Ting Ting Yang ◽  
Hong Jun Li
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Exchange Process ◽  
Generalized Predictive Control ◽  
Matlab Simulation ◽  
Control Effect ◽  
Heat Exchange Process ◽  
Complex Control System ◽  
And Control

The air precooling system heat exchange process is a complex control system with features such as: nonlinear, lag and random interference. So choose Generalized Predictive Control Algorithm that has low model dependence, good robustness and control effect, as well as easy to implement. But due to the large amount of calculation of traditional generalized predictive control and can't juggle quickness and overshoot problem, an improved generalized predictive control algorithm is proposed, then carry out the MATLAB simulation, the experimental results show that the algorithm can not only greatly reduce the amount of computation, but also can restrain the overshoot and its rapidity.

Machine design and control strategy for wide-speed-range PMSG systems

2015 ◽  
Vol 34 (1) ◽  
pp. 92-109 ◽  
Author(s):  
Jianxin Shen ◽  
Dong-Min Miao
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
Power Converter ◽  
Machine Design ◽  
Pwm Rectifier ◽  
Content Type ◽  
Speed Range ◽  
Converter Topologies ◽  
Wide Speed Range ◽  
And Control

Purpose – The purpose of this paper is to focus on the machine design and control strategy of the permanent magnet synchronous generator (PMSG) system, especially utilized in variable speed applications, in order to stabilize the output voltage on the dc link over a wide speed range. Design/methodology/approach – Different ac/dc power converter topologies are comparatively studied, each with an accordingly designed PMSG, so as to investigate the influence of the armature winding inductance as well as the relationship between the PMSG and power converter topologies. Findings – Pulse width modulation (PWM) rectifier is preferable for the said application due to its good performance and controllability. Moreover, by employing the PWM rectifier, relatively large inductance of the PMSG is considered for both short-circuit current reduction and field regulation. Originality/value – Field-regulating control is realized with a space vector PWM (SVPWM) rectifier, which can weaken the PMSG magnetic field during high-speed operation, while even properly enhance the field at low speed, ensuring a small change of the PMSG output voltage and a stable dc voltage.

Operation, Control and Verification of Seven-Level Quasi-Z-Source-Based T-Type Inverter

2019 ◽  
Vol 29 (02) ◽  
pp. 2050023
Author(s):  
Ramesh Rahul Jammy ◽  
Kirubakaran Annamalai ◽  
Chinmay Kumar Das
Keyword(s):  
Duty Cycle ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Voltage Level ◽  
Text Type ◽  
Control Schemes ◽  
Operation Control ◽  
Bidirectional Switches ◽  
And Control

In this paper, a novel seven-level Quasi-Z-Source-based [Formula: see text]-type inverter (7L[Formula: see text]qZST[Formula: see text]) is proposed. The proposed inverter is an upgrade of Quasi-Z-source (qZs) network and seven-level [Formula: see text]-type inverter. The 7L qZST[Formula: see text] comprises of three qZs-based impedance networks, two bidirectional switches and an [Formula: see text]-bridge inverter. It owns the advantages of reduced switch count, improved output voltage gain, enhanced reliability and better quality of output voltage and current. The performance of the proposed topology is tested for two different pulse width modulation techniques based on shoot-through control. The first technique offers simple control and operated at a fixed shoot-through duty cycle for realizing output voltage level. The second technique facilitates independent control of each qZs network dc-link voltage and they can be operated at different shoot through duty cycle which overcomes the limitation of first technique with better quality in output voltage. The detailed operation of the proposed topology and control schemes have been elaborated for different switching states for each output voltage level generation. Extensive simulation and experimentation are performed for both the switching schemes to verify their performance under steady state and dynamic conditions. Furthermore, a brief comparison is constructed to highlight the merits of the proposed inverter with conventional topologies.

scholarly journals Modeling and reliability analysis of three phase z-source AC-AC converter

2017 ◽  
Vol 66 (4) ◽  
pp. 731-743
Author(s):  
Hanuman Prasad ◽  
Tanmoy Maity
Keyword(s):  
Reliability Analysis ◽  
Output Voltage ◽  
Closed Loop ◽  
Supply Voltage ◽  
Loop System ◽  
Small Signal ◽  
Closed Loop System ◽  
Voltage Variation ◽  
Three Phase ◽  
Simulation Results

Abstract This paper presents the small signal modeling using the state space averaging technique and reliability analysis of a three-phase z-source ac-ac converter. By controlling the shoot-through duty ratio, it can operate in buck-boost mode and maintain desired output voltage during voltage sag and surge condition. It has faster dynamic response and higher efficiency as compared to the traditional voltage regulator. Small signal analysis derives different control transfer functions and this leads to design a suitable controller for a closed loop system during supply voltage variation. The closed loop system of the converter with a PID controller eliminates the transients in output voltage and provides steady state regulated output. The proposed model designed in the RT-LAB and executed in a field programming gate array (FPGA)-based real-time digital simulator at a fixedtime step of 10 μs and a constant switching frequency of 10 kHz. The simulator was developed using very high speed integrated circuit hardware description language (VHDL), making it versatile and moveable. Hardware-in-the-loop (HIL) simulation results are presented to justify the MATLAB simulation results during supply voltage variation of the three phase z-source ac-ac converter. The reliability analysis has been applied to the converter to find out the failure rate of its different components.

scholarly journals Operation and Control of a Seven-Level V-Clamp Multilevel Converter

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4761
Author(s):  
Yao Xue ◽  
Xiaofeng Yang ◽  
Lutian Yuan ◽  
Trillion Q. Zheng
Keyword(s):  
Power Conversion ◽  
Modulation Method ◽  
Multilevel Converter ◽  
Multilevel Converters ◽  
Output Performance ◽  
Flying Capacitors ◽  
Dynamic Voltage ◽  
Set Up ◽  
And Control ◽  
Laboratory Prototype

Multilevel converters are well suited for high-power and high-quality power conversion. This paper presents a new seven-level V-clamp multilevel converter (VMC) with reduced clamping devices. All phases of the VMC share common DC-link capacitors and realize bidirectional power conversion without flying capacitors. Each branch of the VMC sustains only a single-level voltage of the DC-link capacitors during its commutation process. Hence, the series switches can be controlled as simple as one switch and the dynamic voltage unbalancing issue is avoided. In this paper, the operation principle and the modulation method of the VMC are analyzed in detail. In addition, compensation control for non-ideal factors is designed to improve the output performance. The output fundamental distortion is compensated and the harmonics are reduced. Finally, a laboratory prototype of the seven-level VMC is set up to verify the feasibility of the presented topology and analysis.

scholarly journals Characteristics of electricity quality parameters in agri-food processing plants

2018 ◽  
Vol 10 ◽  
pp. 02022 ◽  
Author(s):  
Krzysztof Necka ◽  
Małgorzata Trojanowska
Keyword(s):  
Control Systems ◽  
Food Processing ◽  
Supply Voltage ◽  
Quality Parameters ◽  
Electrical Drives ◽  
Statistical Measures ◽  
Processing Plants ◽  
Normative Requirements ◽  
And Control

The paper presents the results of electricity quality measurements conducted in six agri-food processing plants equipped with receivers of different sensitivity to the quality of the supply voltage. In particular, statistical assessment has been conducted for the value of the parameters characterizing the supply voltage, describing the parameters using the basic statistical measures and comparing them with the normative requirements. The paper also presents examples of the hazards to electrical drives and control systems caused by such industrial electromagnetic interferences as voltage changes or deformations of voltage waveform.

scholarly journals Design and Analysis of the STATCOM Based on Diode Clamped Multilevel Converter Using Model Predictive Current Control Strategy

2021 ◽  
Vol 23 (3) ◽  
pp. 221-228
Author(s):  
Raaed Faleh Hassan ◽  
Suha Sabah Shyaa
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Control Strategy ◽  
Control Algorithm ◽  
Reactive Power ◽  
Current Control ◽  
Multilevel Converter ◽  
Static Synchronous Compensator ◽  
Multi Level ◽  
And Control

In recent decades, multi-level converters have become popular and used in many power systems applications. Compared with conventional converters, multi-level converters contribute to reducing the voltage stress on the switching devices and enhancing the power quality delivered to the load. In this paper, the study of the five-level diode clamped multilevel converter based static synchronous compensator has been accomplished. Model Predictive current control strategy which a type of modern control algorithms was employed for driving the proposed compensator. The suggested five level converter controlled by model predictive current control is firstly examined to verify that this control algorithm is appropriate for achieving the desired performance. Then the proposed converter and control combination is employed and simulated as a static synchronous compensator in distributed power system. Moreover, in order to examine the robustness of this compensator, the load status is suggested to be heavy inductive. Simulation process has been performed using MATLAB – SIMULINK software package. The results show that the implemented configuration (converter and control algorithm) provides high power quality improvement with adequate reactive power compensation.

A New Asymmetric and Cascaded Switched Diode Multilevel Inverter Topology for Reduced Switches, DC Source and Blocked Voltage on Switches

2019 ◽  
Vol 28 (04) ◽  
pp. 1950064 ◽  
Author(s):  
S. A. Ahamed Ibrahim ◽  
P. Anbalagan ◽  
M. A. Jagabar Sathik
Keyword(s):  
High Power ◽  
Output Voltage ◽  
Multilevel Inverter ◽  
Basic Unit ◽  
Prototype Model ◽  
Multilevel Converter ◽  
Multilevel Converters ◽  
Medium Voltage ◽  
Blocking Voltage ◽  
Inverter Topology

In this paper, a new asymmetric switched diode (ASD) multilevel inverter is presented for medium-voltage and high-power applications. The proposed converter consists of series connection basic unit with full-bridge inverter. In addition to this, a cascaded switched diode (CSD) structure is recommended to generate the higher number of voltage levels. Seven different algorithms are presented to determine the magnitudes of DC sources in CSD topology. To prove the advantages of proposed multilevel converter over recent multilevel converters in terms of blocking voltage, numbers of IGBTs and on-state switches are presented. To show the authority of the proposed multilevel inverter, it is simulated using MATLAB/Simulink and is experimentally tested using prototype model for 13-level inverter. Finally, various output voltage and current waveforms are shown to prove the dynamic behavior of proposed inverter.

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