Coordinated Voltage and Reactive Power Control of Power Distribution Systems with Distributed Generation

Distribution system voltage and VAR control (VVC) is a technique that combines conservation voltage reduction and reactive power compensation to operate a distribution system at its optimal conditions. Coordinated VVC can provide major economic benefits for distribution utilities. Incorporating distributed generation (DG) to VVC can improve the system efficiency and reliability. The first part of this dissertation introduces a direct optimization formulation for VVC with DG. The control is formulated as a mixed integer non-linear programming (MINLP) problem. The formulation is based on a three-phase power flow with accurate component models. The VVC problem is solved with a state of the art open-source academic solver utilizing an outer approximation algorithm. Applying the approach to several test feeders, including IEEE 13-node and 37-node radial test feeders, with variable load demand and DG generation, validates the proposed control. Incorporating renewable energy can provide major benefits for efficient operation of the distribution systems. However, when the number of renewables increases the system control becomes more complex. Renewable resources, particularly wind and solar, are often highly intermittent. The varying power output can cause significant fluctuations in feeder voltages. Traditional feeder controls are often too slow to react to these fast fluctuations. DG units providing reactive power compensation they can be utilized in supplying voltage support when fluctuations in generation occur. The second part of this dissertation focuses on two new approaches for dual-layer VVC. In these approaches the VVC is divided into two control layers, slow and fast. The slow control obtains optimal voltage profile and set points for the distribution control. The fast control layer is utilized to maintain the optimal voltage profile when the generation or loading suddenly changes. The MINLP based VVC formulation is utilized as the slow control. Both local reactive power control of DG and coordinated quadratic programming (QP) based reactive power control is considered as the fast control approaches. The effectiveness of these approaches is studied with test feeders, utility load data, and fast-varying solar irradiance data. The simulation results indicate that both methods achieve good results for VVC with DG

SAS Macros for Calculation of Population Attributable Fraction in a Cohort Study Design

The population attributable fraction (PAF) is a useful measure for quantifying the impact of exposure to certain risk factors on a particular outcome at the population level. Recently, new model-based methods for the estimation of PAF and its confidence interval for different types of outcomes in a cohort study design have been proposed. In this paper, we introduce SAS macros implementing these methods and illustrate their application with a data example on the impact of different risk factors on type 2 diabetes incidence.

Bpop: an efficient program for estimating base population allele frequencies in single and multiple group structured populations

Base population allele frequencies (AF) should be used in genomic evaluations. A program named Bpop was implemented to estimate base population AF using a generalized least squares (GLS) method when the base population individuals can be assigned to groups. The required dense matrix products involving (A22 )-1v were implemented efficiently using sparse submatrices of A-1, where A and A22 are pedigree relationship matrices for all and genotyped animals, respectively. Three approaches were implemented: iteration on pedigree (IOP), iteration in memory (IM), and direct inversion by sparsity preserving Cholesky decomposition (CHM). The test data had 1.5 million animals genotyped using 50240 markers. Total computing time (the product (A22)-11) was 53 min (1.2 min) by IOP, 51 min (0.3 min) by IM, and 56 min (4.6 min) by CHM. Peak computer core memory use was 0.67 GB by IOP, 0.80 GB by IM, and 7.53 GB by CHM. Thus, the IOP and IM approaches can be recommended for large data sets because of their low memory use and computing time

Genomic prediction in a Finnish breeding programme of six-row barley

201

Anatomical Properties of Six Wood Species From Papua

Anatomical properties is necessary for wood species identification. This paper observes anatomical properties of six wood species originated from Papua. Wood species studied include: ketapang (Terminalia complanata K. Schum.); pala hutan (Gymnacranthera paniculata (A.DC.) Warb.); bipa (Pterygota horsfieldii (R.Br.) Kosterm).; kelumpang (Sterculia shillinglawii F. Muell.); manggis/kandis (Pentaphalangium parviflorum); and lancat/lebani (Mastixiodendron pachyclados (K. Schum) Melch.). Anatomical properties were observed according to IAWA (International Association of Wood Anatomists) checklist. The anatomical main properties observed in ketapang wood were vestured pits, prismatic crystals in non-chambered axial parenchyma cells, and druses. Pala hutan main anatomical properties were the presence of tannin tubes and oil cells which were associated with axial parenchyma. Prismatic crystals in axial parenchyma cells, and rays of two distinct sizes were two main anatomical characteristics of bipa and kelumpang wood. Prismatic crystals in chambered axial parenchyma cells was one of characteristics of manggis wood. Vestured pits and scanty paratracheal parenchyma were two main characteristics of lancat wood. For identification pur poses, bipa wood could be distinguished by banded parenchyma; polygonal alternate pits; and prismatic crystals in non- chambered axial parenchyma cells

Kepentingan Tiongkok Memberi Pinjaman Luar Negeri Kepada Venezuela Tahun 2010-2016

This research explains China\u27s policy of providing foreign aid to Venezuela in the economic crisis due to the large foreign debt and falling world oil prices. The strengthening US dollar has been the main cause of the decline in world oil prices over the past few years. In fact, the US dollar was at its highest level in 12 years against the euro, which led to a rise in the US dollar index and falling oil prices. And Venezuela is a country very unprepared for it. As we know that Venezuela depends on their oil sales.The theory used in this research is Neo-liberal is one of the perspectives in International Relations, Neo-liberalism has a pattern of the main driving factor for International cooperation is the International power distribution. And neoliberalism describes the concepts of rationality and prefer to cooperate with institutions and also International organizations to realize their interests. China, which is a very energy-consuming country, is providing overseas aid to Venezuela to meet their growing fuel consumption, as well as to shift US hegemony in Venezuel

Rancang Bangun Sistem Monitoring Ketinggian Air dan Kelembaban Tanah pada Penyiram Tanaman Otomatis dengan Hmi (Human Machine Interface) Berbasis Raspberry Pi Menggunakan Software Node-red

Org/. Diakses tanggal 02 Mei 2017.Tim J, M. 2016. Developing with Node-RED. https://software.intel.com/en-us/articles/developing-with-node-red. Diakses tanggal 02 Mei 2017