标题：Fault-Tolerant Control Strategies for T-Type Three-Level Inverters Considering Neutral-Point Voltage Oscillations
作者：Chen J.; Zhang C.; Chen A.; Xing X.
作者机构：[Chen, J] Shandong University, 12589 Jinan China 250061 (e-mail: email@example.com);[ Zhang, C] School of Control Science and Engineering, Shandong 更多
来源：IEEE Transactions on Industrial Electronics
关键词：Fault tolerance; Fault tolerant systems; Fault-tolerant control; Inverters; neutral-point voltage oscillations; open-circuit fault; Oscillators; reliability; Switches; T-type three-level inverters; Voltage control
摘要：Recently, a few fault-tolerant control strategies have been proposed for T-type three-level inverters to improve the reliability of the inverter system. However, the neutral-point (NP) voltage oscillations suppression is never considered in the previous fault-tolerant control strategies. In order to suppress the NP voltage oscillations when open-circuit fault occurs to NP switches, this paper proposes two novel fault-tolerant control strategies named as improved two-level switching tolerant control (I2LS-TC) and hybrid switching tolerant control (HS-TC). Both methods are implemented by adding an optimal time-offset to the three-phase turn-on times. The corresponding time-offset value of each method is simply calculated considering the phase current and dwell time of [O] state. Moreover, a NP voltage balancing algorithm to eliminate the dc deviation and a dc bias to further reduce the NP voltage oscillations are used in the HS-TC. The performance and comparison of the tolerant controls with respect to the NP voltage oscillations, current total harmonic distortion (THD) and dynamic response are illustrated and analyzed through the simulation and experimental results. IEEE