Comparison of configurations of voltage boosters in PWM inverter with voltage boosters with regenerating circuit augmented by electric double-layer capacitor

In an interior permanent magnet (IPM) motor drive system, which has a regenerating circuit augmented by electric double-layer capacitor (EDLC), two types of configurations of voltage boosters, battery and EDLC are investigated and compared. For one of the configurations, the battery and the EDLC are connected in series and the set of battery and EDLC is connected to the dc link of an inverter through a bidirectional voltage booster. In addition, the EDLC is also connected to the dc link through the other bidirectional voltage booster (configuration I). For the other of the configurations, the battery is connected to the dc link through a bidirectional voltage booster and the EDLC is connected to the dc link through the other bidirectional voltage booster, independently (configuration II). For both configurations, stability and electrical characteristics are investigated for various situation of dc link voltage and output power by simulation. Finally, the results show advantages of the connection I.