Developed cascaded multilevel inverter topology to minimise the number of circuit devices and voltage stresses of switches

In this study, a novel structure for cascade multilevel inverter is presented. The proposed inverter can generate all possible DC voltage levels with the value of positive and negative. The proposed structure results in reduction of switches number, relevant gate driver circuits and also the installation area and inverter cost. The suggested inverter can be used as symmetric and asymmetric structures. Comparing the peak inverse voltage and losses of the proposed inverter with conventional multilevel inverters show the superiority of the proposed converter. The operation and good performance of the proposed multilevel inverter have been verified by the simulation results of a single-phase nine-level symmetric and 17-level asymmetric multilevel inverter and experimental results of a nine-level and 17-level inverters. Simulation and experimental results confirmed the validity and effectiveness performance of the proposed inverter

Fault mode operation strategies for dual H-bridge current flow controller in meshed HVDC grid

Peer ReviewedPreprin

Unidirectional Protection Strategy for Multi-terminal HVDC Grids

Protection issue is identified as the main drawback of emerging multi-terminal HVDC grids. Multi-terminal HVDC grid demands fast short circuit fault current interruption. Fast DC circuit breakers as a promising solution can be implemented as either bidirectional or unidirectional devices. In addition to less implementation cost, the unidirectional DC circuit breakers have less power losses as compared to the bidirectional devices. A protection strategy for multi-terminal HVDC grid based on unidirectional breaking devices is discussed and assessed in this paper. The performance of unidirectional protection strategy is examined under different fault scenarios in a fourterminal MMC-HVDC grid model. Furthermore, the impacts of unidirectional protection strategy on power converters and also current interruption and surge arrester ratings of the DC circuit breakers are discussed

Multi-port Hybrid HVDC Circuit Breaker

This paper proposes a new n-port hybrid dc circuit breaker for offshore multi-terminal HVDC grid application. The n-port dc circuit breaker can substitute n-1 hybrid dc circuit breakers at a dc bus with n-1 adjacent dc transmission lines. The system level behavior of the proposed multi-port hybrid dc circuit breaker is similar to the behavior of other hybrid dc circuit breakers. The operation principles of the proposed multi-port dc circuit breaker are introduced, analyzed and compared to the existing solution in this work. The components ratings are compared to the existing solution and the functionality of proposed device is verified by simulation.status: publishe

Fault mode operation strategies for dual H-bridge current flow controller in meshed HVDC grid

Peer Reviewe