Abstract
Bypassing the faulty power unit(s) of the regenerative cascaded multilevel inverter (CMI) directly results in a series of adverse influences. The existing solutions are not easy to implement and only effective for the Y-connected devices composed of regenerative CMIs. To bypass the faulty power units seamlessly, the corresponding control strategies must guarantee: 1) constant equivalent switching frequency; 2) constant sampling frequency; and 3) constant fundamental voltage amplitude. To this end, a generic fault-tolerant control strategy, which adjusts the carrier frequency and simultaneously changes the CMI dc voltage and/or the modulation ratio, is presented in this paper. It is applicable for the device composed of carrier phase-shifting pulsewidth modulation (CPS-PWM)-based CMIs to ride through faults seamlessly, whether it is a single-phase system, a three-phase system (being it δ -connected or Y-connected), or a multiphase system. The detailed implementation is also analyzed by modeling the output voltage of the CPS-PWM-based CMI. The experimental results verify the validity and superiority of the proposed fault-tolerant strategy for the CPS-PWM-based CMI system with faulty power units.
Original language | English |
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Article number | 8640124 |
Pages (from-to) | 2486-2497 |
Number of pages | 12 |
Journal | IEEE Journal of Emerging and Selected Topics in Power Electronics |
Volume | 7 |
Issue number | 4 |
DOIs | |
Publication status | Published - 12 Feb 2019 |
Keywords
- Carrier phase-shifting pulsewidth modulation (PWM)
- fault-tolerant control
- faulty power units
- regenerative cascaded multilevel inverter (CMI)
- static synchronous compensator (STATCOM)
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering