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.

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 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.

scholarly journals Implementation of 5-Level H-Bridge Inverter with Multicarrier based Modulation Techniques

2020 ◽  
Vol 8 (5) ◽  
pp. 5180-5185
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Reference Signal ◽  
Low Frequency ◽  
Harmonic Spectrum ◽  
Multilevel Inverter ◽  
Modulation Method ◽  
Dc Voltage ◽  
Modulation Technique

Paper Setup must be in A4 size with Margin: Top In the present paper multi carrier sinusoidal modulation technique which is an efficient method of producing control signals is used for a symmetrical inverter with several levels in cascade H Bridge is discussed. The Cascaded H-Bridge performance output levels depend on the DC voltage sources used at the input side. With the help of two DC voltage sources, five level output can be obtained whereas three sources gives levels of seven in output voltage. In this paper, multi-carrier SPWM switching is obtained for switching of multilevel inverter based switches. Two signals are used in this switching method, among which one of the signals is reference which is a low frequency sinusoidal signal and the one is a carrier signal. In case of sinusoidal PWM method of modulation technique, the reference signal is a sinusoidal one and triangular signal can be used as a carrier signal. These types of inverters have the ability to generate inverted output voltage with an efficient harmonic spectrum and reliable output results. This document provides switching signal for H-bridge inverter structure which can improve harmonic performance. The 5-level multilevel inverter is simulated for traditional carrier-based pulse-width modulation (PWM) phase change carrier techniques. The total harmonic performance of the output voltages is analyzed for the two PWM control methods. The performance of the symmetrical PWM CHB is simulated using MATLAB-SIMULINK model. Model results show that THD can be minimized to a limit with level shifted modulation method of the sinusoidal pulse width. The results from the simulations show that the quality of the waveform of the output voltage improves with less loss and with a lower THD.

scholarly journals A single D.C. link Multi-level 42-sided polygonal Voltage Space Vector Generation with lower order harmonic suppression using Switched-Capacitive filter

2021 ◽  
Author(s):  
Gopakumar K
Keyword(s):  
Induction Motor ◽  
Lower Order ◽  
Low Voltage ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Switching Frequency ◽  
Harmonic Suppression ◽  
Space Vector ◽  
Power Circuit ◽  
Multi Level

<div>Abstract—In this work, a multi-level 42-sided polygonal space vector structure (SVS) for suppression of lower order harmonics for Open-End Induction Motor(OEIM) drive applications is proposed. The proposed power circuit topology consists of two inverters feeding an Open-End Induction Motor from either side. The main inverter fed with a single DC link providing active power for motor operation is switched at low switching frequency. The secondary</div><div>inverter fed with a capacitive supply is switched at high frequency to suppress lower order harmonics upto 39th order, up to the base speed of operation allowing maximum utilization of the DC link. The advantages of lower order harmonic suppression in motor phase voltage, for polygonal space vector structures are combined with multi-level inverter topology. This results in lower switching losses in low frequency switching main inverter and low voltage secondary inverter. Use of a single DC link facilitates four quadrant operation of the inverter. The proposed scheme is validated for steady state and dynamic performance by experimental results.</div>

scholarly journals High-Power Multimodular Matrix Converters and Modulation

2021 ◽  
Author(s):  
Jiacheng Wang
Keyword(s):  
High Power ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Input Voltage ◽  
Duty Ratio ◽  
Modulation Scheme ◽  
Switching Frequency ◽  
Space Vector ◽  
Phase Switching ◽  
Matrix Converters

High-power multimodular matrix converters (MMMCs) comprising multiple threephase to single-phase matrix converter modules have emerged as a viable topology candidate for medium-voltage adjustable speed drives. As a combination of direct power conversion and cascaded multilevel structure, the MMMCs inherit features such as elimination of dc capacitors, four quadrant operation capability, employment of lowvoltage devices only, and superior output waveform quality under a limited device switching frequency. Due to their particular topological structure, modulation scheme design for the MMMCs is not straightforward and complicated. The presented work is mainly focused on development of suitable modulation schemes for the MMMCs. Several viable schemes as well as their corresponding switching patterns are proposed and verified by both simulation and experimental results. In order for the MMMCs to produce sinusoidal waveforms at both input and output ac terminals, a direct transfer matrix based modulation scheme is presented. It is revealed that a suitable modulation strategy for the MMMCs should aim at fabricating the total input current on the primary side of the isolation transformer. For topologies with more than two modules in cascade on each output phase, switching period displacement is necessary among modules to generate multilevel output waveforms. An indirect space vector based modulation scheme for the MMMCs is developed. With a few presumptions satisfied and viewed from a certain perspective, the MMMCs can still be modeled indirectly and be divided into fictitious rectifier and inverter stages. Therefore, space vector modulation methods can be independently applied to both stages for duty ratio calculation, before the results are converted and combined for determining per-phase output pulses. A new output switching pattern providing improved harmonic performance is also proposed. A novel modulation scheme based on diode rectifier emulation and phase-shifted sinusoidal pulse-width modulation is proposed. The method sacrifices input power factor adjustment, but enables the use of an indirect module construction leading to significantly reduced device count and complexity. Strategy for reducing additional switchings caused by input voltage ripples is also implemented and explained. In addition to simulation verifications, all the proposed schemes are further tested experimentally on a low-voltage prototype built in the lab. Details about the prototype implementation are introduced.

scholarly journals COMPARISON OF METHODS FOR COMPENSATION FOR DAMAGE TO H-CELLS IN HIGH-VOLTAGE CASCADE FREQUENCY CONVERTERS

2021 ◽  
Vol 3 (55) ◽  
pp. 24-31
Author(s):  
V. Busher ◽  
◽  
O. Glazeva ◽  
Du Xin ◽  
◽  
...  
Keyword(s):  
High Voltage ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Comparison Of Methods ◽  
Space Vector Pwm ◽  
Space Vector ◽  
Line Voltage ◽  
Third Harmonic ◽  
Frequency Converters ◽  
Voltage Frequency

Purpose. The aim of this work is to find a method of controlling high-voltage frequency converters that would provide the smallest voltage drop on the motor, the least loads and oscillation of electromagnetic torque in an accident modes, and evaluate the effectiveness of pulse width modulation (PWM) methods with the injection of third harmonic and space-vector PWM in emergency modes. Methodology. We have applied the mathematical simulation of the electric drive “High voltage frequency converter with cascaded H-bridges – High power asynchronous machine” in Matlab/SimPowerSystem software for comparison of four PWM types – Sinusoidal PWM (SPWM), Balanced sinusoidal PWM (BSPWM), Balanced PWM with injected third harmonic (THPWM) and Space Vector PWM (SVPWM). Results. The method of balancing the line voltage minimizes shock loads during the transition from normal to emergency mode due to such a shift of the zero point and rotation of the phase vectors, in which the amplitude of the line voltage decreases to the minimum possible value, the spatial position of linear vectors remains unchanged. The conditions of optimal injection of the 3rd harmonic are found, which increases the efficiency of power supply use by 7… 30 % in comparison with symmetric sinusoidal PWM. But in some accidents (6-4-4, 4-3-2, 3-2-2) the 3rd harmonic is not effective. The method of balancing the space vectors provides the same conditions and increases the utilization of power supplies by 15.6 %, regardless of the number of damaged modules, which increases the amplitude of the 1st harmonic in case of accidents by 10 ... 26 % compared with sinusoidal PWM. Comparison of methods of space vector PWM (SVPWM), balancing of phase-to-phase voltage with the injection of the 3rd harmonic (THPWM) with sinusoidal PWM shows that SVPWM is the best method at damage of one or two modules and during normal work of the converter (except for the 3-3-2 configuration), ie in the most common cases. Originality. For the first time, a comparison of all methods of pulse-width modulation in emergency modes and the optimal method for each type of accident for 3-6-stage frequency converters is indicated. Practical value of the work is to provide the necessary mathematical apparatus for calculating signals using BSPWM, THPWM and SVPWM in emergency modes. References 17, table 1, figures 6.

A Neural Network Based Space-Vector PWM Controller for Motor Drive

2013 ◽  
Vol 816-817 ◽  
pp. 1002-1005
Author(s):  
Zhi Yuan
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Integrated Circuit ◽  
Pulse Width Modulation ◽  
Motor Drive ◽  
Switching Frequency ◽  
Space Vector ◽  
The Neural Network ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

This paper proposed an artificial neural network (ANN) based space vector pulse width modulation (SVPWM) for motor drive which fully covers the undermodulation and overmodulation regions. A neural network has the advantage of very fast implementation of an SVPWM algorithm that can increase the converter switching frequency, particularly when a dedicated application-specific integrated circuit chip is used in the modulator. Finally, in the environment of MATLAB/Simulink with the Neural Network Toolbox builds the simulation model of system with proposed ANN-SVPWM controller. The simulation results show that the performances of the motor drive with artificial-neural-network-based SVPWM are excellent.

scholarly journals SPACE VECTOR PWM SIGNAL GENERATION FOR ANY MULTILEVEL INVERTER BY USING REVERSE MAPPING TECHNIQUE

2014 ◽  
pp. 25-33
Author(s):  
K. VARALAKSHMI ◽  
K. BALAKRISHNA
Keyword(s):  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Mapping Technique ◽  
Space Vector Pwm ◽  
Space Vector ◽  
Switching Sequence ◽  
Multilevel Inverters ◽  
Reference Space ◽  
A New Technique ◽  
Reverse Mapping

This paper proposes a generalized method for the generation of space vector pulse width modulation (SVPWM) signals for multilevel inverters. In the proposed method, the actual sector containing the tip of the reference space vector need not be identified. A method is presented to identify the center of a sub hexagon containing the reference space vector. Using the center of the sub hexagon, the reference space vector is mapped to the innermost sub hexagon, and the switching sequence corresponding to a two-level inverter is determined. A new technique is proposed in this paper, by which these two-level vectors are translated to the switching vectors of the multilevel inverter by adding the center of the sub hexagon to the two-level vectors. The proposed method can be extended to any n-level inverter, and a generalized algorithm is proposed. The scheme is explained for a five-level inverter, and experimental results are presented for a three-level inverter and seven level Inverter.

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