Generalized Switching Modification Method Using Carrier Shift for DC-link Capacitor RMS Current Reduction in Real-Time Implementation

• Published in: IEEE transactions on industrial electronics (1982) Vol. 66; no. 8; pp. 5992 - 6001
• Main Authors: Choi, Ki-Young, Kim, Sang-Il, Jung, Sang-Min, Kim, Rae-Young
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Boost converter; capacitor lifetime; capacitor ripple current; Capacitors; carrier shifting; Direct current; Electric converters; Fourier series; Inductors; Inverters; Mathematical analysis; Power factor; Pulse duration modulation; Pulse width modulation; Reactive power; Real time; Real-time systems; Reduction; Switches; Switching; switching modification; three-phase inverter
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2018.2873160

In this paper, a generalized switching modification method is proposed to reduce the root-mean-square (rms) current flowing into a dc-link capacitor in a dc-dc-ac structure consisting of a boost converter and a three-phase inverter. To analyze the current flowing into the capacitor, we analyze the currents at the respective converter and inverter sides. Based on this analysis, we derive an analytical method to find the modification time between the converter and inverter pulsewidth modulation (PWM) carriers through a Fourier series and approximation to facilitate real-time implementation. Real-time implementation of the modification time calculated by the derived method is described. To verify the validity of the proposed method, experimental results are presented based on a 1-kVA dc-dc-ac prototype. The proposed method has a better capacitor rms current reduction performance than the conventional method in various inverter power factors and PWM strategies. Especially, it has an excellent performance in mid-power factor level (0.95-0.1).