Harmonic reduction under unbalanced operating conditions of PV‐connected cascaded H‐bridge multilevel inverters using fault tolerant adaptive phase‐shifted pulse width modulation

2019 ◽  
Vol 29 (4) ◽  
pp. e2814 ◽  
Author(s):  
Fatih Eroğlu ◽  
Mehmet Kurtoğlu ◽  
Ali Osman Arslan ◽  
Ahmet Mete Vural
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Fault Tolerant ◽  
Operating Conditions ◽  
Multilevel Inverters ◽  
Harmonic Reduction

Position Control of Hydraulic Actuators Using Fuzzy Pulse Width Modulation (PWM)

2015 ◽  
Vol 735 ◽  
pp. 294-298 ◽  
Author(s):  
Wei Ying Lai ◽  
Nurfarahin Onn ◽  
Collin Howe Hing Tang ◽  
Mohamed Hussein
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Solenoid Valve ◽  
Operating Conditions ◽  
Hydraulic Actuators ◽  
Non Linear ◽  
Fuzzy Logic Approach ◽  
Logic Approach ◽  
Non Linear System

Hydraulic actuators are widely employed for industrial automation for its high power over weight ratio, functionality in tough operating conditions and low cost. However, the dynamics of hydraulic systems are non-linear and the system subjected to non-smooth and discontinuous non-linearities due to directional change of valve opening, friction, valve overlap and changes of hydraulic pressure acted on valve spool. Taking into account the effect of nonlinear parameter variations such as bulk modulus, compressibility of oil or viscosity of oil, fuzzy logic approach is chosen. Fuzzy control can adapt the inconstant working condition and non-linear system alongside of its robustness. For PWM controlled hydraulic component such as solenoid valve, effective approximation of the flow properties in a solenoid valve is essential. In this paper, the effect of fuzzy logic approach incorporated on pulse width modulation (PWM) controlled hydraulic system is to be investigated and experimentally verified.

scholarly journals Improved harmonic injection pulse-width modulation variable frequency triangular carrier scheme for multilevel inverters

2020 ◽  
Vol 13 (14) ◽  
pp. 3146-3154
Author(s):  
Mohammad Sadegh Orfi Yeganeh ◽  
Mohammad Sarvi ◽  
Frede Blaabjerg ◽  
Pooya Davari
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Variable Frequency ◽  
Multilevel Inverters ◽  
Harmonic Injection ◽  
Injection Pulse

scholarly journals Research on Modified Hybrid Frequency Modulation Technology of Type-III Asymmetric CHB Multilevel Inverters

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 263
Author(s):  
Manyuan Ye ◽  
Wei Ren ◽  
Qiwen Wei ◽  
Guizhi Song ◽  
Zhilin Miao
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Output Line ◽  
Line Voltage ◽  
Multilevel Inverters ◽  
Type Iii ◽  
Hybrid Frequency ◽  
Frequency Pulse

Asymmetric Cascaded H-bridge (ACHB) level inverters can output more voltage waveforms with fewer cascaded units while ensuring the quality of output voltage waveforms, so they have attracted more and more attention. Taking the topology of Type-III asymmetric CHB multilevel inverters as the research object, a Modified Hybrid Frequency Pulse Width Modulation (MHF-PWM) strategy is proposed in this paper. This modulation strategy overcomes the local overshoot of low-voltage unit in the presence of traditional Hybrid Frequency Pulse Width Modulation (HF-PWM), thus completely eliminating the low frequency harmonics in the output voltage waveform of Type-III ACHB nine-level inverters, and the Total Harmonic Distortion (THD) of output line voltage of the modulation strategy is lower than that of PS-PWM strategy in the whole modulation degree, which effectively improves the quality waveform of the output line voltage. At the same time, the strategy can also improve the problems of current backflow and energy feedback caused by the high-voltage unit pouring current to the low-voltage unit, thereby reducing the imbalance of the output power of the high-voltage and low-voltage units. Finally, the Matlab/Simulink simulation model and experimental platform are established to verify the validity and practicality of the modulation strategy.

Sequential Control of Multichannel On–Off Valves for Linear Flow Characteristics Via Averaging Pulse Width Modulation Without Flow Meter: An Application for Pneumatic Valves

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Kanchit Pawananont ◽  
Thananchai Leephakpreeda
Keyword(s):  
Flow Rate ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Single Channel ◽  
Flow Characteristics ◽  
Volumetric Flow Rate ◽  
Operating Conditions ◽  
Mean Flow ◽  
Flow Meter ◽  
Linear Flow

Control of on–off valves for linear flow characteristics is a challenging design problem due to nonlinearity of valve mechanism and fluidic properties under various operating conditions. In this study, averaging pulse width modulation (PWM) is proposed as a control valve signal by implementing PWM with predetermined duty period so that overflow at the open position and underflow at the closed position are divided proportionately around desired mean flow rates during entire cycle periods. Multichannels in a parallel pattern are implemented to yield linear flow characteristics with higher resolution than a single channel. With pressure and temperature measurements, the volumetric flow rate is determined by an empirical model of flow characteristics across flow control valves at given operating conditions. The experimental results on achieving the desired volumetric flow rate of air under actual flow conditions without a flow meter are presented for viability of the proposed methodology in practical uses.

Certain Investigation on Multilevel Inverters for Photovoltaic Grid Connected System

2016 ◽  
Vol 25 (09) ◽  
pp. 1650108 ◽  
Author(s):  
P. Karuppusamy ◽  
G. Vijayakumar ◽  
S. Sathishkumar
Keyword(s):  
Solar Energy ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Electrical Energy ◽  
Pv System ◽  
Multilevel Inverters ◽  
Dc Power ◽  
Harmonic Content ◽  
Ac Power

This paper presents a photovoltaic (PV) system to convert the solar energy into electrical energy. DC power from PV system is converted into AC power using multilevel inverters. Cascaded H-bridge (CHB) inverter and diode clamped inverter (DCI) are used to convert variable DC power into sinusoidal AC power. Harmonic content is the important part to improve the efficiency of the inverter. Harmonics of CHB inverter and DCI are simulated and analyzed with different pulse width modulation (PWM) techniques.

Fast minimum loss space vector pulse‐width modulation algorithm for multilevel inverters

2014 ◽  
Vol 7 (6) ◽  
pp. 1590-1602 ◽  
Author(s):  
Yilmaz Sozer ◽  
David A. Torrey ◽  
Aparna Saha ◽  
Hung Nguyen ◽  
Nathaniel Hawes
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Minimum Loss ◽  
Space Vector ◽  
Multilevel Inverters

scholarly journals Three Level Inverter Controlled UPFC for Harmonic Reduction using Space Vector Pulse Width Modulation Technique

2020 ◽  
Vol 9 (5) ◽  
pp. 734-738
Keyword(s):  
Pulse Width ◽  
Power Flow ◽  
Pulse Width Modulation ◽  
Unified Power Flow Controller ◽  
Power Transfer ◽  
Harmonic Reduction ◽  
Switching Pattern ◽  
Transfer Capability ◽  
Power Quality Improvement ◽  
Power Flow Controller

Unified Power Flow Controller (UPFC) is one of the most important device in FACTS family, this device in this work is used for power quality improvement. In this paper three level inverter is proposed for UPFC for the reduction of harmonics and for the enhancement of power transfer capability. SVPWM technique decides switching pattern of three level inverter. Therefore, in this paper this method is applied for controlling the three level inverter output. The proposed method is applied on four bus system and results are compared with UPFC without three level inverter. Results demonstrated that the proposed method effectively decreasing the harmonics and increasing the power transfer capability.

scholarly journals Performance evaluation and comparison of diode clamped multilevel inverter and hybrid inverter based on PD and APOD modulation techniques

2019 ◽  
Vol 8 (2) ◽  
pp. 143
Author(s):  
N. Susheela ◽  
P. Satish Kumar
Keyword(s):  
Pulse Width ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Multilevel Inverters ◽  
Number Of Components ◽  
Modulation Techniques ◽  
Modulation Methods

<p>The popularity of multilevel inverters have increasing over the years in various applications without use of a transformer and has many benefits. This work presents the performance and comparative analysis of single phase diode clamped multilevel inverter and a hybrid inverter with reduced number of components. As there are some drawbacks of diode clamped multilevel inverter such as requiring higher number of components, PWM control method is complex and capacitor voltage balancing problem, an implementation of hybrid inverter that requires fewer components and less carrier signals when compared to conventional multilevel inverters is discussed. The performance of single phase diode clamped multilevel inverter and hybrid multilevel inverter for seven, nine and eleven levels is performed using phase disposition, alternate phase opposition disposition sinusoidal pulse width modulation techniques. Both the multilevel inverter are implemented for the above mentioned multicarrier based Pulse Width Modulation methods for R and R-L loads.  The total harmonic distortion is evaluated at various modulation indices. The analysis of the multilevel inverters is done by simulation in matlab / simulink environment.</p>

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