scholarly journals A Systematic Study on the Harmonic Overlap Effects for DC/AC Converters under Low Switching Frequency Modulation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2811
Author(s):  
Ze Wang ◽  
Zhen He ◽  
Chao Gao
Keyword(s):  
High Power ◽  
Frequency Modulation ◽  
Heat Dissipation ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Industrial Applications ◽  
Voltage Source ◽  
Switching Frequency ◽  
Ac Converters ◽  
Power Capability

In most high power industrial applications, the low switching frequency modulations (LSFM) are usually implemented to reduce power loss and heat dissipation pressure. However, there are some unexpected influences caused by the low order harmonic sinusoidal pulse width modulation (SPWM), such as the imbalanced submodule power in cascaded half-bridge inverter (CHB) and limited output power capability in H-bridge neutral-point-clamped (HNPC) converter. This paper starts by generalizing the basic characteristic of two-level SPWM, then deeply investigates the influences of low-frequency modulation on the operation of the circuits. They are classified into three mechanisms and generally named as harmonic overlap effect (HOE). The corresponding solutions to copy with the mechanisms are proposed and verified in some topologies through high-power simulations in simulations. In addition, a comprehensive summary of the influences and solutions of these effects on typical high power converters is drawn. The design rules of the modulation schemes for multilevel voltage source converters (VSCs) at low switching frequency are also proposed.

Synchronized Symmetrical Bus-Clamping PWM Strategies for Three Level Inverter: Applications to Low Switching Frequencies

2011 ◽  
Vol 12 (2) ◽  
Author(s):  
Sreenivasappa Bhupasandra Veeranna ◽  
Udaykumar R Yaragatti ◽  
Abdul R Beig
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
High Performance ◽  
Pulse Width Modulation ◽  
Industrial Applications ◽  
Voltage Source ◽  
Switching Frequency ◽  
Space Vector ◽  
Digital Implementation ◽  
Switching Losses

The digital control of three-level voltage source inverter fed high power high performance ac drives has recently become a popular in industrial applications. In order to control such drives, the pulse width modulation algorithm needs to be implemented in the controller. In this paper, synchronized symmetrical bus-clamping pulse width modulation strategies are presented. These strategies have some practical advantages such as reduced average switching frequency, easy digital implementation, reduced switching losses and improved output voltage quality compared to conventional space vector pulse width modulation strategies. The operation of three level inverter in linear region is extended to overmodulation region. The performance is analyzed in terms THD and fundamental output voltage waveforms and is compared with conventional space vector PWM strategies and found that switching losses can be minimized using bus-clamping strategy compared to conventional space vector strategy. The proposed method is implemented using Motorola Power PC 8240 processor and verified on a constant v/f induction motor drive fed from IGBT based inverter.

scholarly journals Simplified Space Vector Pulse Width Modulation Based on Switching Schemes with Reduced Switching Frequency and Harmonics for Five Level Cascaded H-Bridge Inverter

2018 ◽  
Vol 7 (2) ◽  
pp. 127
Author(s):  
B. Sirisha ◽  
Dr. P. Satishkumar
Keyword(s):  
Pulse Width Modulation ◽  
Low Frequency ◽  
Industrial Applications ◽  
Harmonic Spectrum ◽  
Switching Frequency ◽  
Segment Sequence ◽  
Space Vector ◽  
Switching Sequence ◽  
Line Voltage ◽  
Filter Size

This paper presents a simplified control strategy of SVPWM with a three segment switching sequence and 7 segment switch frequency for high power multilevel inverter. In the proposed method, the inverter switching sequences are optimized for minimization of device switching sequence frequency and improvement of harmonic spectrum by using the three most derived switching states and one suitable redundant state for each space vector. The proposed 3-segment sequence is compared with conventional 7-segment sequence similar for five level Cascaded H-Bridge inverter with various values of switching frequencies including very low frequency. The output spectrum of the proposed sequence design shows the reduction of device switching frequency and states current and line voltage. THD this minimizing the filter size requirement of the inverter, employed in industrial applications. Where  sinusoidal output voltage is required<em>.</em>

scholarly journals Simplified Space Vector Pulse Width Modulation based on Switching Schemes with Reduced Switching Frequency and Harmonics for Five Level Cascaded H-Bridge Inverter

2018 ◽  
Vol 8 (5) ◽  
pp. 3417 ◽  
Author(s):  
B. Sirisha ◽  
P. Satishkumar
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Industrial Applications ◽  
Harmonic Spectrum ◽  
Switching Frequency ◽  
Segment Sequence ◽  
Space Vector ◽  
Switching Sequence ◽  
Filter Size

This paper presents a simplified control strategy of spacevector pulse width modulation technique with a three segment switching sequence and seven segment switching sequence for high power applications of multilevel inverters. In the proposed method, the inverter switching sequences are optimized for minimization of device switching frequency and improvement of harmonic spectrum by using the three most desired switching states and one suitable redundant state for each space vector. The proposed three-segment sequence is compared with conventional seven-segment sequence for five level Cascaded H-Bridge inverter with various values of switching frequencies including very low frequency. The output spectrum of the proposed sequence design shows the reduction of device switching frequency, current and line voltage THD, thereby minimizing the filter size requirement of the inverter, employed in industrial applications, where sinusoidal output voltage is required.

Development of a Damper Control System for Combined Cycle Thermal Gas Power Plant

2014 ◽  
Author(s):  
Amit Kumar Mondal ◽  
Vindhya Devalla ◽  
Vivek Kaundal ◽  
Kamal Bansal
Keyword(s):  
Heat Dissipation ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Solenoid Valve ◽  
Combined Cycle ◽  
Solenoid Coil ◽  
Hydraulic Damper ◽  
Wireless Control ◽  
Damper Control ◽  
Gas Power Plant

This paper addresses a technique to solve the problem of heat dissipation in solenoid coil of the solenoid valve which is controlling the hydraulic damper by using pulse width modulation (PWM) switching technique with low frequency. In addition to this damper controlling is achieved via wireless controlling. By using PWM based low frequency switching technique the gas turbine trip will be protected. PWM is achieved by microcontroller and wireless control is done by ZigBee.

High‐power‐factor dimmable LED driver with low‐frequency pulse‐width modulation

2016 ◽  
Vol 9 (10) ◽  
pp. 2139-2146 ◽  
Author(s):  
Hung‐Liang Cheng ◽  
Yong‐Nong Chang ◽  
Chun‐An Cheng ◽  
Chien‐Hsuan Chang ◽  
Yu‐Hung Lin
Keyword(s):  
Power Factor ◽  
High Power ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Led Driver ◽  
High Power Factor ◽  
Frequency Pulse

scholarly journals Adaptive Phase-Shifted PWM based on Particle Swarm Optimization for Cascaded H-Bridge Inverter with Unequal Dc-link Voltages

2018 ◽  
Vol 7 (4.15) ◽  
pp. 469
Author(s):  
Pakedam Lare ◽  
Byamakesh Nayak ◽  
Srikanta Dash ◽  
Jiban Ballav Sahu
Keyword(s):  
Particle Swarm Optimization ◽  
Particle Swarm ◽  
Pso Algorithm ◽  
Industrial Applications ◽  
High Order ◽  
Control Technique ◽  
Voltage Source ◽  
Switching Frequency ◽  
Swarm Optimization ◽  
The Cost

The cascaded H-Bridge Multilevel Inverter has been found a promising technology in industrial applications because of its higher voltage with less distortion production. Various PWMs techniques have been proposed to push the harmonics frequencies higher than the switching frequency and thus reduces the THD as compared to non-carrier control technique based upon grid frequency. The Phase-Shifted PWM technique has an advantage over others PWM techniques because its harmonics orders are multiples of switching frequency and also depend on the number of levels of the inverter. The phase shifting angle is uniform when the equal voltage sources are adopted. However, in applications where sets of different voltage source levels feed the H-Bridge cells, the Phase Shifted PWM suffers its high order harmonics elimination capability. As a solution to alleviate this problem, an adaptive variable angle approach is proposed in this paper using Particle Swarm Optimization (PSO) algorithm to eliminate desired higher order harmonics. The algorithm is used to minimize the cost function based on high order sideband harmonics elimination equations. The results through MATLAB/Simulink environment shown in this paper confirm the reduction of sideband harmonics of higher orders, and the overall THD.  

scholarly journals Transformerless Multilevel Voltage-Source Inverter Topology Comparative Study for PV Systems

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3261 ◽  
Author(s):  
Adyr A. Estévez-Bén ◽  
Alfredo Alvarez-Diazcomas ◽  
Juvenal Rodríguez-Reséndiz
Keyword(s):  
Leakage Current ◽  
Clean Energy ◽  
Industrial Applications ◽  
Renewable Energies ◽  
International Standards ◽  
Voltage Source ◽  
Switching Frequency ◽  
Multilevel Inverters ◽  
Pv Systems ◽  
Advantages And Disadvantages

At present, renewable energies represent 25% of the global power generation capacity. The increase in clean energy facilities is mainly due to the high levels of pollution generated by the burning of fossil fuels to satisfy the growing electricity demand. The global capacity of generating electricity from solar energy has experienced a significant increase, reaching 505 GW in 2018. Today, multilevel inverters are used in PV systems to convert direct current into alternating current. However, the use of multilevel inverters in renewable energies applications presents different challenges; for example, grid-connected systems use a transformer to avoid the presence of leakage currents. The grid-connected systems must meet at least two international standards analyzed in this work: VDE 0126-1-1 and VDE-AR-N 4105, which establish a maximum leakage current of 300 mA and harmonic distortion maximum of 5%. Previously, DC/AC converters have been studied in different industrial applications. The state-of-the-art presented in the work is due to the growing need for a greater use of clean energy and the use of inverters as an interface between these technologies and the grid. Also, the paper presents a comparative analysis of the main multilevel inverter voltage-source topologies used in transformerless PV systems. In each scheme, the advantages and disadvantages are presented, as well as the main challenges. In addition, current trends in grid-connected systems using these schemes are discussed. Finally, a comparative table based on input voltage, switching frequency, output levels, control strategy used, efficiency, and leakage current is shown.

Suppressing Electromagnetic Interference in Switching Converters by Chaotic Duty Modulation

2017 ◽  
Author(s):  
Yuhong Song
Keyword(s):  
Frequency Band ◽  
Frequency Modulation ◽  
Electromagnetic Interference ◽  
Chaotic Signal ◽  
Industrial Applications ◽  
Switching Frequency ◽  
Switching Converters ◽  
Wide Frequency Band ◽  
Switching Converter ◽  
Driving Pulse

The switching converter generates serious electromagnetic interference (EMI), which impairs other devices‘ performance and harms human being’s health. As a way of chaos technique, chaotic modulation has been developed to suppress EMI of the switching converter by dispersing the energy into a wide frequency band and smoothing the peaks of the EMI spectrum. Unlike the well-studied chaotic frequency modulation, the chaotic duty modulation is concerned in this dissertation, which is just to change the duty of the transistor driving-pulse while maintains the fixed switching frequency. Chaotic duty modulation is realized by appending an external chaotic signal to the existing PWM module of the switching converter, which is practicable without the loss of the generality. It is thus verified that this proposal of using chaotic duty modulation in switching converters for EMI suppression is feasible and lays a foundation for industrial applications. ...

scholarly journals Induction drive system with DSTATCOM based asymmetric twin converter

2020 ◽  
Vol 11 (4) ◽  
pp. 1826
Author(s):  
P Anusha ◽  
B V Rajanna
Keyword(s):  
High Power ◽  
Harmonic Distortion ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Switching Frequency ◽  
Power Electronics Converters ◽  
Drive Control ◽  
In Series ◽  
Output Module

High power demands are usually met by advanced power electronics converters in several large utility and electric drives applications. Applications from high power drives commonly uses solution based multi pulse and multilevel converters. A common DC link with atleast one voltage source converter (VSC) working with almost fundamental switching frequency are used in converters of multipulse type, and each output module is connected with the multipulse transformer in series. When compared to that of solution with single-VSC, Several VSCs generating different triggering pulses are adjused in order to achieve current injected with low specified total harmonic distortion (THD) with losses of abridged switching. Huge structure in complexity and expensive cost expenditure of the multipulse transformer is the major limitation of this scheme. DC link split capacitors in addition are eliminated by modifying the topology of the circuit. Thus, the independent voltages of the DC capacitor are controlled and decreased in number and the flow of third harmonic current component in the transformer is eliminated. The scheme of the designed controller is depending on the derived mathematical system model. Simulaion observation is used to check the scheme performance and efficiency in a detailed way with drive control technique.

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