A Modular Multilevel DC/DC Converter with Fault Blocking Capability for HVDC Interconnects

Abstract

A modular multilevel dc/dc converter, termed the DC-MMC, that can be deployed to interconnect HVDC networks of different or similar voltage levels is introduced in this paper. Its key features include: 1) bidirectional power flow; 2) step-up and step-down operation; and 3) bidirectional fault blocking similar to a dc circuit breaker. The kernel of the DC-MMC is a new class of bidirectional single-stage dc/dc converters utilizing interleaved strings of cascaded sub modules. The DC-MMC operation is analyzed and an open loop voltage control strategy that ensures power balance of each sub module capacitor via circulating ac currents is proposed. Here, we are using the Ann controller. Artificial neuron is supposed to mimic the action of a biological neuron, i.e., to accept many different signals, xi, from many neighboring neurons and to process them in a pre-defined simple way. The goal of the neural network is to solve problems in the same way that the human brain would, although several neural networks are much more abstract.