Monitoring and Protection of Power Distribution Networks with IEC 61850-9-2 Standard

In the modern power grid, communication plays a vital role in making the system more reliable and secure. The communications network transfers data between different units to a control center or to Intelligent Electric Devices (IEDs) in order to accurately control or protect the modern power system. The paper discussed possible ways to monitor the measured values for protecting the power system according to IEC 61850-9-2 (sample value). The sequence of the process consists of streaming the sample value packet, decoding it, and phasor extraction and filtering, which are discussed here. To validate the research, Sundom Smart Grid was used as a pilot to measure the values converted to digital form (IEC 61850-9-2) and to stream it to the system through a highly secure communications network. To decode the SV packet, two scenarios are presented in the case study, based on processing useful features of the IEC 61850-9-2 standard-based raw data streamed from the SSG, including μPMU in a range of embedded instruments and a real-time simulator. The main result of this paper is an algorithm for analyzing SV packets and determining whether the network is operating normally.©2020 IET. This paper is a postprint of a paper submitted to and accepted for publication in 15th International Conference on Developments in Power System Protection (DPSP 2020) and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.fi=vertaisarvioitu|en=peerReviewed

Finite control set model predictive control-a powerful control algorithm for grid-connected power converters

© 2016 IEEE. This paper presents a detailed description of Finite Control Set Model Predictive Control applied to power converters. Some key features related to this methodology are presented and compared with model predictive control based space vector modulation methods. The basic models, principles, control diagrams, and simulation results are presented to provide a comparison between them. The analysis is performed on a three-phase/ two-level voltage source inverter, which is one of the most common converter topologies used in industry. Among the conclusions are the feasibility and great potential of Finite Control Set Model Predictive Control due to the advanced signal-processing capability, particularly for power systems with a reduced number of switching states and more complicated principles

Hardware-in-the-loop Testing of Line Differential Protection Relay Based on IEC 61850 Process Bus

The term digital substation refers to the process of managing operations between intelligent primary devices and distributed Intelligent Electric Devices (IEDs) interfaced with a highly secure communications network. The process bus is the first part of the interface between the primary instruments (such as the current and voltage transformers and protection devices) and is an important part of digitalization. This paper describes a method for constructing an interface between measurement instruments and protection devices based on the IEC 61850 standard. Two scenarios are considered to examine the performance of the power system protection in a transmission line between two substations. Both a conventional and an IEC 61850-9-2 (sampled values) approach are implemented to feed the measured values to the protection devices. Trip signals are then also sent to the circuit breakers using IEC 61850-8-1 (GOOSE message). Comparing this method with conventional technology, the outcomes for the digital substation are more accurate and reliable thanks to the rapid reaction of protection devices and the speed at which the trip signal is received. The new process bus method has been tested by implementing a hardware-in-the-loop platform, consisting of a real-time simulator (OPAL-RT eMEGAsim), StandAlone Merging Units (SAMUs), and line differential protection.©2020 IET. This paper is a postprint of a paper submitted to and accepted for publication in 15th International Conference on Developments in Power System Protection (DPSP 2020) and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.fi=vertaisarvioitu|en=peerReviewed

ارزیابی فصلی آلودگی آفلاتوکسین M1 در شیرهای خام عرضه شده در مراکز جمع آوری شیر استان قزوین طی فصول سال های 94-95

مقدمه و اهداف : آفلاتوکسین ها از جمله ترکیبات فوق العاده تراتوژن، جهش زا، سمی و سرطان زا می باشد. انواع قارچ های آسپرژیلوس از مهم ترین گونه های مولد آفلاتوکسین های B1 و B2 و G1 و G2 در مواد غذائی می باشند . آفلاتوکسین M1 متابولیت هیدروکسیله شده آفلاتوکسین B1 هست . هدف از این مطالعه بررسی وضعیت آلودگی شیرهای خام مراکز جمع آوری شیر خام استان قزوین از نظر میزان آلودگی به آفلاتوکسین M1 می باشد . روش کار : در مطالعه حاضر 60 نمونه شیر خام گاو طی 4 فصل ( آذر ماه سال 1394 تا تیر ماه سال 1395 ) از استان قزوین جمع آوری شد . جهت ارزیابی میزان آلودگی به AFM1 در نمونه های جمع آوری شده از روش الایزا (Enzyme-linked immunoabsorbent assay ) استفاده شد . یافته ها : AFM1 در 34 نمونه از 60 نمونه شیر خام برداشت شده در دامنه ی از 3-10×25/6 تا 3-10×87/127 (ppb) تشخیص داده شد. در تمامی نمونه هائی که از نظر وجود AFM1 مثبت ارزیابی شدند ، محتوی این مایکوتوکسین بسیار پائین تر از محدوده قانونی امریکا ( 5/0 ppb ) بود اما به ترتیب 30% و 5% از مجموع نمونه های اخذ شده میزان آلودگی بالاتر از حدود قانونی اروپا (05/0 ppb ) و ایران ( 1/0 ppb ) را نشان دادند . بحث و نتیجه گیری : گرچه مطالعه حاضر متوسط میزان بروز بالاتری از AFM1 در فصل زمستان را به تصویر می کشد ( 3-10×71/40 ppb ) اما در 05/0>P تفاوت آماری معنا داری بین نمونه های فصول مختلف وجود ندارد . از آنجا که آلودگی شیر با آفلاتوکسین خطری بالقوه برای سلامت انسان محسوب می شود ، شیر و سایر محصولات لبنی بایستی به صورت دوره ای از نظر آلودگی با آفلاتوکسین مورد کنترل قرار گیرند . میزان آلودگی AFM1 مشاهده شده ، بیانگر لزوم پایش مداوم جهت کاهش میزان مواجهه مصرف کنندگان و حفظ سلامت عمومی می باشد . کاهش سطح AFB1 در خوراک حیوانات می تواند به عنوان گامی اولیه در راستای جلوگیری از انتقال AFM1 به انسان باشد

Determination of contamination of Lead and Cadmium in Canola and safflower in around of Isfahan Still Company (ESCO) and Compare this pollution with oil extracted from them

Background and aims: Contaminants are a disturbing factor for ecosystems, among which “heavy metals” are considered as significant due to their physiological effects at low concentrations on organisms. This contamination is concentrated several times more in the products that are available in markets as oil than in natural plant, and in each consumption time, a considerable amount, higher than authorized amount of heavy metals may enter into consumer’s body. This study was designed and conducted for this aim to investigate the contamination rate with lead and cadmium in canola (Brassica napus) and safflower (Carthamus tinctorius L.) in the farms around Isfahan Steel factory and to compare this contamination with oil extracted from them. Methods: The present study was conducted in 2012. The samples were randomly selected from oil seeds of B. napus and C. tinctorius L. in the farms within a 20 to 50 km distance from Isfahan Steel factory. Samples were assigned to two groups and only group 1 underwent washing operation with deionized water. The amount of lead and cadmium in seeds and their oil was measured by atomic absorption. Data were analyzed by SPSS. Results: The results indicated that the lowest lead concentration was 0.00 µg.g in washed B. napus samples and the highest lead concentration was 24.74 µg.g in C. tinctorius L. oil extracted by traditional method. The amount of lead was less in washed seeds than unwashed seeds, with a significant difference for B. napus seeds (P<0.05). No cadmium contamination was observed in B. napus and C. tinctorius L. plants and the oils extracted from them. Conclusion: A rate of contamination with lead was seen in the plants cultivated near Isfahan Steel factory, but no contamination with cadmium was seen. In view of the lead amount being less in the group washed with deionized water than the unwashed group, it is recommended to do washing steps of oil seeds in the factory at low volume, with clean water, and carefully prior to oil tapping

Zebrafish Tmem230a cooperates with the Delta/Notch signaling pathway to modulate endothelial cell number in angiogenic vessels

During embryonic development, new arteries, and veins form from preexisting vessels in response to specific angiogenic signals. Angiogenic signaling is complex since not all endothelial cells exposed to angiogenic signals respond equally. Some cells will be selected to become tip cells and acquire migration and proliferation capacity necessary for vessel growth while others, the stalk cells become trailer cells that stay connected with pre-existing vessels and act as a linkage to new forming vessels. Additionally, stalk and tip cells have the capacity to interchange their roles. Stalk and tip cellular responses are mediated in part by the interactions of components of the Delta/Notch and Vegf signaling pathways. We have identified in zebrafish, that the transmembrane protein Tmem230a is a novel regulator of angiogenesis by its capacity to regulate the number of the endothelial cells in intersegmental vessels by co-operating with the Delta/Notch signaling pathway. Modulation of Tmem230a expression by itself is sufficient to rescue improper number of endothelial cells induced by aberrant expression or inhibition of the activity of genes associated with the Dll4/Notch pathway in zebrafish. Therefore, Tmem230a may have a modulatory role in vessel-network formation and growth. As the Tmem230 sequence is conserved in human, Tmem230 may represent a promising novel target for drug discovery and for disease therapy and regenerative medicine in promoting or restricting angiogenesis