Novel ripple reduction method using three-level inverters with unipolar PWM

This paper proposes a novel method to reduce voltage and current ripple for the inverters by using three-level inverters with unipolar pulse width modulation (PWM) (3LFB-2U). A simple technique of switching signal generation by using carrier-based dipolar modulation of three-phase three-level inverters is extended to single-phase inverters that can be done by generating all possible switching patterns of the single-phase three-level inverters. Moreover, the concept of carrier-based dipolar modulation and the construction of reference voltages from desired output voltage and added zero voltage to control unipolar switching is also shown. The research results reveal that the proposed method can reduce the voltage and current ripple. Furthermore, the voltage and current harmonics can reduce by 27.80% and 1.79%, respectively less than two-level inverters without a loss of a simple modulation to generate the switching signals.

Download Full-text

AC Current Ripple in Three-Phase Four-Leg PWM Converters with Neutral Line Inductor

Energies ◽

10.3390/en14051430 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1430

Author(s):

Aleksandr Viatkin ◽

Riccardo Mandrioli ◽

Manel Hammami ◽

Mattia Ricco ◽

Gabriele Grandi

Keyword(s):

Numerical Simulations ◽

Pulse Width Modulation ◽

Neutral Line ◽

Experimental Tests ◽

Performance Comparison ◽

Design Parameters ◽

Switching Frequency ◽

Three Phase ◽

Ac Current ◽

Current Ripple

This paper presents a comprehensive study of peak-to-peak and root-mean-square (RMS) values of AC current ripples with balanced and unbalanced fundamental currents in a generic case of three-phase four-leg converters with uncoupled AC interface inductors present in all three phases and in neutral. The AC current ripple characteristics were determined for both phase and neutral currents, considering the sinusoidal pulse-width modulation (SPWM) method. The derived expressions are simple, effective, and ready for accurate AC current ripple calculations in three- or four-leg converters. This is particularly handy in the converter design process, since there is no need for heavy numerical simulations to determine an optimal set of design parameters, such as switching frequency and line inductances, based on the grid code or load restrictions in terms of AC current ripple. Particular attention has been paid to the performance comparison between the conventional three-phase three-leg converter and its four-leg counterpart, with distinct line inductance values in the neutral wire. In addition to that, a design example was performed to demonstrate the power of the derived equations. Numerical simulations and extensive experimental tests were thoroughly verified the analytical developments.

Download Full-text

Equivalent Phase Current Harmonic Elimination in Quadruple Three-Phase Drives Based on Carrier Phase Shift Method

Energies ◽

10.3390/en13112709 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2709

Author(s):

Xuchen Wang ◽

Hao Yan ◽

Giampaolo Buticchi ◽

Chunyang Gu ◽

He Zhang

Keyword(s):

Carrier Phase ◽

Pulse Width Modulation ◽

Torque Ripple ◽

Current Harmonics ◽

Phase Current ◽

Harmonic Elimination ◽

Three Phase ◽

High Control ◽

Machine Drives ◽

Transportation Applications

Multiphase drives are entering the spotlight of the research community for transportation applications with their high power density and the possibility of high fault tolerance. The multi three-phase drive is one of the main types of multiphase drives that allows for the direct adoption of commercial three-phase converters and high control flexibility. The elimination of high-frequency current harmonics will reduce the flux linkage harmonics, torque ripple, vibration and noise in machine drives. Therefore, this work introduces a new method to the modelling of equivalent phase current in multi three-phase drives with the double integral Fourier analysis method. A new carrier-based pulse-width modulation (CPWM) method is introduced to reduce the equivalent phase current harmonics by applying proper carrier phase angle to each subsystem in the multi three-phase drives. The proposed angles of carrier signals are analyzed for quadruple three-phase drives, and the corresponding experimental results confirm the significance of the proposed phase-shifted CPWM method to eliminate the equivalent phase current harmonics.

Download Full-text

Effect of load current harmonics on vibration of three-phase generator

MATEC Web of Conferences ◽

10.1051/matecconf/201819711023 ◽

2018 ◽

Vol 197 ◽

pp. 11023

Author(s):

I Made Wiwit Kastawan

Keyword(s):

Single Phase ◽

Electrical Power ◽

Electrical Power System ◽

Negative Effects ◽

Load Current ◽

Current Harmonics ◽

Three Phase ◽

Non Linear ◽

Electrical Loads ◽

Linear Loading

Almost all today electrical loads are considered non-linear such as switch mode power supply (SMPS) for powering computer and mobile phone or variable speed drive (VSD) for driving home and industrial electric motors. These loads generate ac non-sinusoidal current containing a lot of harmonics as indicated by its high total harmonics distortion (THD) figure. Current harmonics bring negative effects into all electrical power system components, including three-phase generator. This paper provides analysis of load current harmonics effects on vibration of three-phase generator. Three different laboratory experiments have been conducted i.e. three-phase linear resistive loading, non-linear loading with a three-phase ac/dc converter and non-linear loading with three single-phase capacitor filtered ac/dc converters. Results show that the higher load current harmonics content the higher is vibration of the three-phase generator. Non-linear loading with a three-phase ac/dc converter that generate about 24.7% THD gives an increase of 4.3% and 5.5% in average of vertical and horizontal vibrations of the three-phase generator respectively. Further, non-linear loading with three single-phase capacitor filtered ac/dc converters that generate THD as high as 74.9% gives significant increase of 28.1% and 23.6% in average of vertical and horizontal vibrations respectively.

Download Full-text

A Study on Current Ripple Reduction Due to Offset Error in SRF-PLL for Single-phase Grid-connected Inverters

Journal of the Korean Institute of Illuminating and Electrical Installation Engineers ◽

10.5207/jieie.2014.28.11.068 ◽

2014 ◽

Vol 28 (11) ◽

pp. 68-76

Author(s):

Seon-Hwan Hwang ◽

Young-Gi Hwang ◽

Soon-Kurl Kwon

Keyword(s):

Single Phase ◽

Ripple Reduction ◽

Current Ripple ◽

Offset Error

Download Full-text

A new simplified SVPWM algorithm based on modified carrier signal

Sba Controle & Automação Sociedade Brasileira de Automatica ◽

10.1590/s0103-17592011000500009 ◽

2011 ◽

Vol 22 (5) ◽

pp. 545-557 ◽

Cited By ~ 1

Author(s):

Raymundo Cordero Garcia ◽

João Onofre Pereira Pinto

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Experimental Results ◽

Phase Inverter ◽

Switching Patterns ◽

Three Phase ◽

Execution Speed ◽

Simplified Algorithm ◽

Mathematical Operations ◽

Three Phase Inverter

This paper presents a simplified algorithm of space vector pulse width modulation (SVPWM) for a two-level three-phase inverter, which can operate in undermodulation and overmodulation modes. In other simplifications founded in literature, the reference voltages are modified and compared with a triangular carrier to estimate the switching states of the inverter. However, this paper proposes the modification of the carrier signal instead of the references. This procedure reduces the number of mathematical operations and increases the execution speed of SVPWM algorithm in DSPs or FPGAs. The reference voltages are sinusoidal, even for overmodulation mode. Simulation and experimental results proves that the proposed simplification produces the same switching patterns than conventional SVPWM, is simpler and is faster than other simplifications.

Download Full-text

A Hybrid Self-Voltage Balanced Multilevel Inverter Topologies for Induction Motors

International Journal of Emerging Science and Engineering ◽

10.35940/ijese.e2517.117421 ◽

2021 ◽

Vol 7 (4) ◽

pp. 1-8

Author(s):

Sanjeev Kumar ◽

◽

H.K. Verma ◽

M.P.S. Chawla ◽

◽

...

Keyword(s):

Single Phase ◽

Pulse Width Modulation ◽

Operating Mode ◽

Multilevel Inverter ◽

Motor Drive ◽

Induction Motor Drive ◽

Voltage Balancing ◽

Three Phase ◽

Capacitor Voltage ◽

Sinusoidal Pulse Width Modulation

A hybrid structured asymmetric switching capacitor multilevel inverter (ASC-MLI) is suggested in this work. The notion behind presenting this topology is to reduce the device count and DC sources as compared with conventional MLI. The step by step operating mode of single phase ASC-MLI is presented and by doing slight modifications the same configuration is used in three phase utility application and electric drive. The proposed configurations utilize major benefits of self-voltage balancing capability of capacitor voltage, which is independent from different load type and modulations index. To generate the switching pulse for corresponding switches the multi-carrier based sinusoidal pulse width modulation (MCS-PWM) technique is used; in addition to this simulation result are obtained using MATLAB/Simulink 2016b software version. Simulation results of an induction motor drive connected as three phase load highlights good performance of 17-level MLI.

Download Full-text

Sector Subdivision Based SVPWM Strategy of Neutral-Point-Clamped Three-Level Inverter for Current Ripple Reduction

Energies ◽

10.3390/en12142734 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2734 ◽

Cited By ~ 2

Author(s):

Guozheng Zhang ◽

Bingxu Wei ◽

Xin Gu ◽

Xinmin Li ◽

Zhanqing Zhou ◽

...

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Small Region ◽

Output Current ◽

Switching Sequence ◽

Output Performance ◽

Ripple Reduction ◽

Average Current ◽

Current Ripple ◽

Continuous Pulse

This paper presents a sector subdivision based space vector pulse width modulation (SVPWM) strategy with reduced current ripple for a three-level inverter. Using the output current ripple theory, closed-form expressions of average current ripple vectors for both continuous and discontinuous switching sequences are derived. Based on the sector and triangle distributions of conventional SVPWM strategy, each triangle is further divided into three small-regions. Then the switching sequence with the lowest magnitude of the average current ripple vector is applied in every small-region, so that the advantages of continuous pulse width modulation (CPWM) and discontinuous pulse width modulation (DPWM) under different modulation index conditions are combined to reduce the current ripple in the whole modulation range. The output performance of the proposed strategy is compared with the conventional CPWM and DPWM strategy, and experimental results verify that the proposed strategy could reduce the current ripple of three-level inverters effectively.

Download Full-text