Analysis and Comparison of Peak-to-Peak Current Ripple in Two-Level and Multilevel PWM Inverters

Abstract

Abstract-Three-phase multilevel inverters are used in many medium-and high-power applications such as motor drives and grid-connected systems. Despite numerous PWM techniques for multilevel inverters have been developed, the impact of these modulation schemes on the peak-to-peak output current ripple amplitude has not been addressed yet. In this paper the analysis and the comparison of current ripple for two-and three-level voltage source inverters are given. Reference is made to optimal and popular modulation, so-called centered PWM, easily obtained by both carrier-based modulation (phase disposition, with proper common-mode voltage injection) and space vector modulation (nearest three vectors). It is shown that the peak-to-peak current ripple amplitude in three-level inverters can be determined on the basis of the ripple in two-level inverters, obtaining the same results as by directly analyzing the output voltage waveforms of the three-level inverters. This procedure can be readily extended to higher level numbers. The proposed analytical developments are verified by both numerical simulations and experimental tests.Index Terms-Multilevel inverters; three-level inverter; output current ripple; carrier-based PWM; space vector PWM.

Comparison of Output Current Ripple in Single and Dual Three-Phase Inverters for Electric Vehicle Motor Drives

“…In particular, the analysis of the output current ripple amplitude in three-phase 2L inverters has been recently introduced in [13][14][15]. The extension to 2L multiphase inverters is given in [16][17][18], and compared in [19], whereas the extension to 3L three-phase inverters is given in [20] and [21]. In general, the knowledge of peak-to-peak current ripple amplitude in inverter motor drives allows one to optimize the switching frequency (and the associated losses), handle and minimize the acoustic noise, and mitigate the electromagnetic interference [17,22].…”

Online Optimal Switching Frequency Selection for Grid-Connected Voltage Source Inverters

“…This representation is valid for any inverter that supplies motor loads and/or grids [33]. Figure 9 shows the circuit diagram of the grid connected inverter, which includes an inductor (L) to represent the grid-inductance in series with a sinusoidal voltage source (v g ) for the grid to be represented.…”

“…Figure 9 shows the circuit diagram of the grid connected inverter, which includes an inductor (L) to represent the grid-inductance in series with a sinusoidal voltage source (v g ) for the grid to be represented. This representation is valid for any inverter that supplies motor loads and/or grids [33]. Figure 9 shows the circuit diagram of the grid connected inverter, which includes an inductor ( L ) to represent the grid-inductance in series with a sinusoidal voltage source ( g v ) for the grid to be represented.…”

“…Figure 9 shows the circuit diagram of the grid connected inverter, which includes an inductor ( L ) to represent the grid-inductance in series with a sinusoidal voltage source ( g v ) for the grid to be represented. This representation is valid for any inverter that supplies motor loads and/or grids [33].…”

Attenuation of Conducted EMI for Three-Level Inverters Through PWM

“…Compared with regular constant switching frequency PWM (CSFPWM), VSFPWM can reduce switching losses and EMI noise peak and keep the same current ripple peak value. For three-level VSI, [19] has studied the current ripple through space vector analysis. Nevertheless, it is much complicated and VSFPWM has not been implemented for three-level inverters.…”