Current Ripple Prediction and DPWM Based Variable Switching Frequency Control for Full ZVS Range Two Parallel Interleaved Three-Phase Inverters

2021 ◽  
pp. 1-1
Author(s):  
Jianliang Chen ◽  
Qiang Han ◽  
Weijian Han ◽  
Zhen Xin
Keyword(s):  
Frequency Control ◽  
Switching Frequency ◽  
Three Phase ◽  
Current Ripple

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

Energies ◽  
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.

scholarly journals Switching frequency control method based on short prediction horizon control algorithm of Quasi-Z source inverter

2018 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Shengchao Li ◽  
Sile Ma ◽  
Xiaojing Ma ◽  
Xiangyuan Jiang ◽  
Shuai Li
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
Frequency Control ◽  
Switching Frequency ◽  
Output Current ◽  
Prediction Horizon ◽  
Simulation And Experiment ◽  
The Relationship ◽  
Current Ripple

In order to overcome the problem of large inductance current ripple and poor output current quality caused by lower switching frequency in model predictive control (MPC). A short prediction horizon control algorithm is proposed, and the relationship between the prediction horizon and the switching frequency is analyzed, which also considered the influence of the switching frequency of the inverter. In the proposed algorithm the optimal vector is selected based on the historical switching state. Finally the proposed method can effectively reduce the inductor current ripple and improve the output current quality of the inverter, which is proved by simulation and experiment.

scholarly journals AC Current Ripple Harmonic Pollution in Three-Phase Four-Leg Active Front-End AC/DC Converter for On-Board EV Chargers

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 116
Author(s):  
Aleksandr Viatkin ◽  
Riccardo Mandrioli ◽  
Manel Hammami ◽  
Mattia Ricco ◽  
Gabriele Grandi
Keyword(s):  
Smart Grids ◽  
Harmonic Distortion ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Voltage Source ◽  
Switching Frequency ◽  
Voltage Source Converters ◽  
Three Phase ◽  
Ac Current ◽  
Current Ripple

Three-phase four-leg voltage-source converters have been considered for some recent projects in smart grids and in the automotive industry, projects such as on-board electric vehicles (EVs) chargers, thanks to their built-in ability to handle unbalanced AC currents through the 4th wire (neutral). Although conventional carrier-based modulations (CBMs) and space vector modulations (SVMs) have been commonly applied and extensively studied for three-phase four-leg voltage-source converters, very little has been reported concerning their pollution impact on AC grid in terms of switching ripple currents. This paper introduces a thorough analytical derivation of peak-to-peak and RMS values of the AC current ripple under balanced and unbalanced working conditions, in the case of three-phase four-leg converters with uncoupled AC-link inductors. The proposed mathematical approach covers both phase and neutral currents. All analytical findings have been applied to two industry recognized CBM methods, namely sinusoidal pulse-width modulation (PWM) and centered PWM (equivalent to SVM). The derived equations are effective, simple, and ready-to-use for accurate AC current ripple calculations. At the same time, the proposed equations and diagrams can be successfully adopted to design the conversion system basing on the grid codes in terms of current ripple (or total harmonic distortion (THD)/total demand distortion (TDD)) restrictions, enabling the sizing of AC-link inductors and the determination of the proper switching frequency for the given operating conditions. The analytical developments have been thoroughly verified by numerical simulations in MATLAB/Simulink and by extensive experimental tests.

scholarly journals Analysis of Equivalent Inductance of Three-phase Induction Motors in the Switching Frequency Range

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 120 ◽  
Author(s):  
Milan Srndovic ◽  
Rastko Fišer ◽  
Gabriele Grandi
Keyword(s):  
Induction Motors ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Switching Frequency ◽  
Frequency Range ◽  
Leakage Inductance ◽  
Squirrel Cage ◽  
Three Phase ◽  
Ripple Amplitude ◽  
Current Ripple

The equivalent inductance of three-phase induction motors is experimentally investigated in this paper, with particular reference to the frequency range from 1 kHz to 20 kHz, typical for the switching frequency in inverter-fed electrical drives. The equivalent inductance is a basic parameter when determining the inverter-motor current distortion introduced by switching modulation, such as rms of current ripple, peak-to-peak current ripple amplitude, total harmonic distortion (THD), and synthesis of the optimal PWM strategy to minimize the THD itself. In case of squirrel-cage rotors, the experimental evidence shows that the equivalent inductance cannot be considered constant in the frequency range up to 20 kHz, and it considerably differs from the value measured at 50 Hz. This frequency-dependent behaviour can be justified mainly by the skin effect in rotor bars affecting the rotor leakage inductance in the considered frequency range. Experimental results are presented for a set of squirrel-cage induction motors with different rated power and one wound-rotor motor in order to emphasize the aforesaid phenomenon. The measurements were carried out by a three-phase sinusoidal generator with the maximum operating frequency of 5 kHz and a voltage source inverter operating in the six-step mode with the frequency up to 20 kHz.

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