When the Modular Multilevel Converter (MMC) fails on AC side, operating characteristics of MMC will be damaged. If system wants to retain stable for a long time in process operation, it is obliged design control strategy case asymmetric fault. In this article, based feedback linearization principle adopted diminish negative sequence current caused by breakdown, and DC voltage controller devised...

After microgrid transition from the normal operation to the islanded operation the system impedance changes considerably and it affects on the harmonic voltages of the microgrid. In this paper the voltage and current THD before and after islanding are studied with different microgrid configurations. Simulations are also made by applying negative sequence filtering in control system of converter...

Under unbalanced supply condition low order harmonics will appear at the input and output terminals of the PWM AC to DC converter. Based on the positive and negative sequence components, an unbalanced transfer matrix in terms of the input phase voltages is derived. An on-line method using a neural network (NN) is used to implement this transfer matrix. It is shown that by using an additional lo...

background: antimicrobial peptides play a role as effectors substances in the immunity of vertebrate and inverte­brate hosts. in the current study, antimicrobial peptide was isolated from the haemolymph of the american cock­roach, periplaneta americana . methods: micrococcus luteus as gram-positive bacteria and escherichia coli as gram-negative bacteria were candi­date for injection. induction ...

background: investigation was designed to evaluate the behavioral changes in children receiving dental treatment while they have been administered combination of midazolam/ketamine or midazolam/promethazine. materials and methods: this was a randomized double blind clinical trial with cases being selected from those uncooperative children aged 2 to 6 years from those referred for treatment unde...

the aim of current study was to investigate the nucleotide sequence of seven trna genes in mitochondrial gene of khorasan’s native chicken and identification of possible mutations in it. for performing it, this part of the gene was cloned using the specific amplification initiators and cloned in the plasmid ptg19-t vector in dh5α strain of e-coli after the sampling and extracting the dna from w...

Voltage source converter (VSC)-based high voltage direct current (VSC-HVDC) interconnectors can realize accurate and fast control of power transmission among AC networks, and provide emergency power support for AC networks. VSC-HVDC interconnectors bring exclusive fault characteristics to AC networks, thus influencing the performance of traditional protections. Since fault characteristics are r...