A reliable and efficient single‐phase modular multilevel inverter topology

Abstract

Bilevel inverters are replaced by multilevel inverters due to their capability of producing quality output voltage with low total harmonic distortion (THD). On the contrary, increase in number of semiconductor switches has questioned the reliability of the multilevel inverter topologies. To enhance the reliability, this paper proposes a single-phase five-level inverter topology with inherent fault-tolerant feature. The proposed inverter can sustain faults in sources and semiconductor switches by amending the switching combinations. No healthy switch is needed to be bypassed during the fault to ensure the optimum utilization of the switches. An analysis on the basis of reliability, cost, and efficiency is carried out of the proposed inverter and compared with the existing topologies. To prove the claim, the experimental results of the developed hardware model is analyzed and compared with the simulation results of MATLAB/SIMULINK.

Resilient multilevel inverter topology with improved reliability

“…Moreover, it requires a higher number of conducting switches either in healthy or faulty operation, resulting in lower reliability. A nine‐level fault‐tolerant MLI topology with 16 semiconductor switches and 4 dc sources has been proposed in [27, 28]. The major drawback is the requirement of a higher number of conducting switches to generate a particular voltage level, which results in low efficiency.…”

FPGA‐based implementation of single‐phase seven‐level quasi‐Z‐source inverter

“…In addition, it provides single-stage power conversion with buck-boost capability, thus improving the efficiency of the system compared with two-stage conversion due to reduced component count. 6 Moreover, several topologies are developed in recent years in terms of reduced component count, capacitor voltage balancing, control complexity, and the number of direct current (dc) sources. To address this problem, quasi-Z-source (qZs) inverter (qZSI) is developed, which inherits the same features of ZSI.…”

“…Among these, CHB is most preferred due to its modularity feature. 6 Moreover, several topologies are developed in recent years in terms of reduced component count, capacitor voltage balancing, control complexity, and the number of direct current (dc) sources. However, the switch count remains a major constraint in developing new topologies.…”

Fault‐tolerant switched capacitor–based boost multilevel inverter

“…The impedance network–interfaced power electronic converters are normally ST resilient since it will not allow a sudden and fast increase of currents through semiconductor devices in the event of a short circuit, which allows the protection circuit to respond without causing any damage to switching devices. To address the reliability issues such as switch failure and source failure of conventional multilevel inverters, different fault tolerable topologies are presented . An additional capacitor clamped phase leg–based structure was proposed to provide fault tolerance operation and stiff neutral point voltage .…”

“…To address the reliability issues such as switch failure and source failure of conventional multilevel inverters, different fault tolerable topologies are presented. [19][20][21] An additional capacitor clamped phase leg-based structure was proposed to provide fault tolerance operation and stiff neutral point voltage. 22 An optimal control strategy was proposed 23 for multiple device open-circuit fault, which is a more common fault in active neutral point clamped inverter.…”