Current-Ripple Prediction for Three-Phase PWM Converters

Abstract

The three-phase pulsewidth-modulation (PWM) converter is one of the most widely used topologies for power conversion. In order to design PWM methods, the influence of PWM methods on the current ripple is needed. This paper studies the current ripple of a three-phase PWM converter with general PWM methods for the design and control of this kind of converter. The current ripple is analyzed with eight different Thevenin equivalent circuits for the eight different voltage vectors. Then, the current-ripple slope and effective time could be achieved for every period. The current ripple could be predicted with both peak and rms values. Analytical predicted results show that discontinuous PWM could generate obviously bigger current ripples than space vector PMW for both peak and rms values with the same conditions. Simulation and experiments are built to verify the analytical results, proving that the theoretical prediction is valid. This analysis provides the basis for the design and control of the PWM method for converters.

Theoretical and Experimental Investigation of Switching Ripple in the DC-Link Voltage of Single-Phase H-Bridge PWM Inverters

“…The low-frequency DC-link voltage component v can be simply calculated on the basis of the amplitude of the low-frequency input current component (8) and the DC-link equivalent impedance Z 2f , as follows:…”

“…Simple and effective expressions for determining the peak-to-peak output current ripple amplitude over the modulation index range, for two-and multilevel inverters, are presented in [7][8][9]. An extension to multiphase inverters and a comparison among the cases with different phase numbers is presented in [10].…”

Analysis of Equivalent Inductance of Three-Phase Induction Motors in the Switching Frequency Range

“…The phenomenon of varying the rotor leakage inductance with frequency, and consequently the equivalent inductance, contributes considerably to motors' characteristics. The estimation of inverter current harmonic distortion, current ripple rms, and peak-to-peak current ripple amplitude [1][2][3][4]8,9] is strongly affected as well. Especially, in the case of multiphase IMs, the equivalent inductance of each α-β plane seen from the stator side may additionally vary due to the different arrangements of machine connections [4].…”

Analysis and Minimization of Output Current Ripple for Discontinuous Pulse-Width Modulation Techniques in Three-Phase Inverters

“…Recently, the importance of the calculation of current ripple peak-to-peak envelope has been recognized in addition to the rms analysis [15,16], and it has been analyzed for three-phase [17][18][19][20][21][22] and multiphase inverters [23]. The current ripple peak-to-peak amplitude has been analyzed partially also for the discontinuous modulation [20], comparing the two modulation techniques, i.e., SVPWM and DPWM1.…”

“…The current ripple peak-to-peak amplitude has been analyzed partially also for the discontinuous modulation [20], comparing the two modulation techniques, i.e., SVPWM and DPWM1. However, the calculation of the current ripple peak-to-peak and further analysis includes only the DPWM1 method, lacking in depth and details.…”