scholarly journals A Design Method of the Transmitting Waveform of Electromagnetic Sounding Based on Selective Harmonic Elimination

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Lihui Gao ◽  
Yongkang Liu ◽  
Nan Chen ◽  
Haolin Li ◽  
Niaona Zhang ◽  
...  
Keyword(s):  
Pulse Width Modulation ◽  
Design Method ◽  
Binary Sequence ◽  
Guizhou Province ◽  
Electromagnetic Sounding ◽  
Harmonic Elimination ◽  
Selective Harmonic Elimination ◽  
Neural Network Algorithm ◽  
Different Depths ◽  
Artificial Neural Network Algorithm

The exploration target at different depths through the ground-airborne frequency domain electromagnetic method (GAFDEM) is detected by transmitting waveforms at different frequencies. When taking these different depths into detail, arbitrarily distributed frequencies are needed. However, the current transmitting waveforms are mostly in a fixed frequency ratio or frequency difference, which fails to meet the requirements of exploration accuracy and efficiency at the same time. Therefore, as a solution to this problem, this paper proposes a transmitting waveform design method based on selective harmonic eliminated pulse width modulation (SHEPWM) technology. In the SHEPWM method, three transmitting waveforms with the desired spectrum are obtained by directly controlling the switching angles of a binary sequence with an artificial neural network algorithm. Firstly, our study puts forward the basic theories and principles of the full-periodic asymmetric SHEPWM waveform. Secondly, the study, through simulation, realizes the pseudorandom, depth-focused, and layer-identification waveform with different detection depths. Finally, the application of the proposed SHEPWM waveform to the geological survey in Kaili City, Guizhou Province, proves the correctness and feasibility of this proposed method.

Selective harmonic elimination pulse width modulation for three-phase cascaded multilevel inverter

2021 ◽  
Author(s):  
Baharuddin Ismail ◽  
Muzamir Isa ◽  
M. Z. Aikhsan ◽  
M. N. K. H. Rohani ◽  
C. L. Wooi ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Harmonic Elimination ◽  
Three Phase ◽  
Selective Harmonic Elimination ◽  
Cascaded Multilevel Inverter

scholarly journals Research on hybrid SHEPWM based on different switching patterns

2019 ◽  
Vol 10 (4) ◽  
pp. 1875 ◽  
Author(s):  
Tao Jing ◽  
Alexander Maklakov ◽  
Andrey Radionov ◽  
Sergei Baskov ◽  
Aleksandra Kulmukhametova
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Effective Means ◽  
Switching Frequency ◽  
Harmonic Elimination ◽  
Switching Patterns ◽  
Control Scheme ◽  
Selective Harmonic Elimination ◽  
Simulation Results ◽  
Additional Hardware

<span>This paper presents a hybrid pulse width modulation (HPWM) strategy based on different switching patterns of selective harmonic elimination pulse width modulation (SHEPWM) for the three-level neutral point clamped (3L-NPC) converter. Specific low-order harmonics can be eliminated by SHEPWM at low switching frequency, while the remaining high-order harmonics can be selected to be simply filtered by additional hardware. Large oscillation waveform usually occurs in the transition instant between two diverse modulation situations, therefore switching between distinct switching patterns can be problematic if no effective means is taken, especially when the effect of smooth and fast transition at any time is considerable. A universal and valid control strategy, which maintains the high-quality output voltage and current, is proposed and implemented in this paper to address this issue. Simulation results obtained from MATLAB/SIMULINK are presented to analyze the performance and validate the feasibility and effectiveness of this control scheme.</span>

New Selective Harmonic Elimination-Pulse-Width Modulation for Cascaded H-bridge Multilevel Inverters

2018 ◽  
Vol 19 (5) ◽  
Author(s):  
Piyush L. Kamani ◽  
Mahmadasraf A. Mulla
Keyword(s):  
Real Time ◽  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Experimental Studies ◽  
Equal Area ◽  
Multilevel Inverters ◽  
Harmonic Elimination ◽  
Selective Harmonic Elimination ◽  
Selection Of

AbstractThis paper presents a univariate equation-based selective harmonic elimination-pulse-width modulation (USHE-PWM) method for cascaded H-bridge (CHB) multilevel inverters (MLIs). Using equal-area criteria, the selection of voltage rating of dc-links have been done. The output voltage is controlled by inserting switching notch at the centre of each level of output voltage. Instead of conventional transcendental SHE-PWM equations, all these calculations are accomplished using univariate equations. This simplifies the real-time implementation of the proposed method greatly, even for the MLI with a large number of levels. The USHE-PWM method can eliminate more harmonics compared with the conventional SHE-PWM methods. While controlling the output voltage, the harmonic pattern remains unaffected. The validity of the proposed method is confirmed by the simulation and experimental studies.

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