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In this study, we propose a new optimization method to determine the control parameters of a step voltage regulator (SVR) to maximize its voltage control characteristic in distribution networks (DNs) with photovoltaic systems. Considering the service life of an SVR, the proposed method evaluates the expected number of tap operations and the voltage control performance based on the past voltage measurements obtained with sensors in the DN. Subsequently, the time series of two control parameters, that is, the reference voltage and the dead bandwidth, are determined for the most improved voltage control characteristic of the SVR, maintaining the number of tap operations within the upper limit. Voltage control simulation using a realistic 6.6‐kV DN model is conducted to show that the proposed method significantly reduces the voltage violation compared with the conventional SVR control using fixed parameters, as well as the alternative SVR operation developed in our previous study, in which the reference voltage was temporally updated. In addition, the simulation results demonstrate that the proposed method realizes efficient tap operations to mitigate the voltage violation, whereas the conventional method requires a much larger number of tap operations to mitigate the voltage violation to the same degree. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this paper, we propose a semicentralized voltage control method utilizing past voltage measurements obtained with sensors in a distribution network (DN) to improve the voltage control performance of a single‐step voltage regulator (SVR). In this method, the SVR basically performs autonomous voltage control referring to the control parameter, the reference voltage, but the parameter is updated with a specific interval via communication. To determine a time series of the reference voltage using the past voltage measurements, the simple averaging method and the probabilistic weighting method are considered. The effect of these methods on the voltage control performance is evaluated with a power flow simulation using a realistic 6.6 kV DN model with photovoltaic systems. The results show that the proposed semicentralized SVR control with these advanced parameter‐updating methods dramatically mitigate voltage violation compared to the conventional SVR operation in which the constant reference voltage is used for 1 year. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Two FtsZ paralogues ( NbFtsZ1 and NbFtsZ2) were isolated from the unicellular green alga Nannochloris bacillaris Naumann. These sequences encoded proteins of 435 and 439 amino acids with tubulin signature motifs (GGGTG[T/S]G), which are important for GTP binding activity. NbFtsZ1 and NbFtsZ2 had four and three introns, respectively, and two different putative core promoters; a TATA box (TATAAAA) and an initiator element (CCCAGG) were located 40 bp and 80 bp upstream of the coding regions of NbFtsZ1 and NbFtsZ2, respectively. Southern blot hybridization and contour-clamped homogeneous electric field electrophoresis showed that N. bacillaris contained at least one copy of each gene and that NbFtsZ1 was located on chromosome 5 and NbFtsZ2 on chromosome 3 or 4. Phylogenetically, NbFtsZ1 and NbFtsZ2 belong to the vascular plant protein families FtsZ1 and FtsZ2, respectively. The FtsZ1 proteins do not contain carboxy-terminal consensus sequences, whereas all FtsZ2 proteins possess the consensus sequence (I/V)PxFL(R/K)(K/R)(K/R). Our study has shown that NbFtsZ2 possesses a similar consensus sequence (VPDFLRRK), whereas NbFtsZ1 does not, further supporting their classification as FtsZ2 and FtsZ1. Escherichia coli ftsZ mutants transformed with cloned NbFtsZ1, and NbFtsZ2 cDNAs were restored for the capacity to divide by binary fission, suggesting that the proteins retained the ability to function in the bacterium. An anti-NbFtsZ2 antibody specifically recognized a single protein band of approximately 51 kDa on an immunoblot of N. bacillaris cellular proteins. Immunostaining of the algal cells with this antibody produced an intense fluorescent signal as a ring near the middle of the cell, which corresponded to the chloroplast division site. [ABSTRACT FROM AUTHOR]