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Title DC-Link Voltage Ripple Analysis of Minimum Loss Discontinuous PWM Strategy in Two-Level Three-Phase Voltage Source Inverters
Authors Junhyuk Lee ; Jung-Wook Park
DOI 10.6113/TKPE.2021.26.2.120
Page pp.120-126
ISSN 1229-2214
Keywords DC-link voltage ripple; DC-link capacitor; Two-level three-phase VSI (Voltage Source Inverter); PWM (Pulse-Width Modulation)
Abstract DC-link capacitors are one of the main components in two-level three-phase voltage source inverters (VSIs); they provide the pulsating input current and stabilize the vacillating DC-link voltage. Ideally, the larger the capacitance of DC-link capacitors, the better the DC-link voltage stabilizes. However, high capacitance increases the cost and decreases the power density of VSI systems. Therefore, the capacitance should be chosen carefully on the basis of the DC-link voltage ripple requirement. However, the DC-link voltage ripple is dependent on the pulse-width modulation (PWM) strategy. This study especially presents a DC-link voltage ripple analysis when the minimum loss discontinuous PWM strategy is applied. Furthermore, an equation for the selection of the minimum capacitance of DC-link capacitors is proposed. Experimental results with R-L loads are also provided to verify the effectiveness of the presented analysis.