A Simplified DC Voltage and Current Ripple Estimation Method for Three-Level ANPC Inverters with Space Vector Modulation

To optimize the DC capacitor bank design for maximum power density, it is essential to estimate the DC-link voltage and current ripples in advance, so that the minimum required capacitance can be obtained. However, existing estimation methods often involve a heavy computation burden, which limits their practical implementation. This paper proposes a simplified estimation method and an analytical model for DClink voltage and current ripples in three-level active neutral point clamped (ANPC) inverters. The proposed method is specifically for three-level ANPCs with space vector modulation (SVM) and eliminates the need for complex calculations typically required in conventional SVM, such as sector selection and dwell time computation. The accuracy of the proposed method is verified through experimental results. To demonstrate the practical value of the proposed estimation method, a case study on a designed three-level ANPC for electric aircraft applications is also performed, showing an improved capacitor bank design in terms of power density.