Substation Research Articles

Characterization of the Operation of a BESS with a Photovoltaic System as a Regular Source for the Auxiliary Systems of a High-Voltage Substation in Brazil

Substation (SS) auxiliary systems (SAux) are facilities responsible for hosting the alternating (AC) and direct current (DC) busbar to serve the equipment and systems that perform the substation’s protection, control, and supervision. External and internal power supplies typically ensure the continuity of such a facility. The electricity support will be restricted to diesel emergency generators (DG) if the external power supply is unavailable due to a contingency. The DG present a slower response time and are susceptible to starting failures. Microgrids with Battery Energy Storage Systems (BESS) paired with photovoltaic systems (PV) are presented as an innovative and reliable solution for powering the SAux. In this article, tests were carried out on the microgrid of the Edson Mororó Moura Institute of Technology (ITEMM) in Brazil to support the use of microgrids BESS/PV in the SAux of a transmission SS of the São Francisco Hydroelectric Company (Chesf). Without an external power supply, BESS commands the action of islanded operation, maintaining both voltage and frequency requirements of the microgrid without load shedding. It was possible to observe all operations of the microgrid. The experimental results showed that the solution proposed in the paper implements a dependable self-dispatchable autonomous power supply.

Fuzzy-Based Simultaneous Optimal Placement of Electric Vehicle Charging Stations, Distributed Generators, and DSTATCOM in a Distribution System

Electric vehicles (EVs) are becoming increasingly popular due to their inexpensive maintenance, performance improvements, and zero carbon footprint. The electric vehicle’s load impacts the distribution system’s performance as the electric vehicle’s adoption rises. As a result, the distribution system’s dependability depends on the precise location of the electric vehicle charging station (EVCS). The main challenge is the deteriorating impact of the distribution system caused by the incorrect placement of the charging station. The distribution system is integrated with the charging station in conjunction with the distribution static compensator (DSTATCOM) and distributed generation (DG) to reduce the impact of the EVCS. This paper presents a fuzzy classified method for optimal sizings and placements of EVCSs, DGs, and DSTATCOMs for 69-bus radial distribution systems using the RAO-3 algorithm. The characteristic curves of Li-ion batteries were utilized for the load flow analysis to develop models for EV battery charging loads. The prime objective of the proposed method is to (1) Reduce real power loss; (2) Enhance the substation (SS) power factor (pf); (3) Enhance the distribution network’s voltage profile; and (4) Allocate the optimum number of vehicles at the charging stations. The proposed fuzzified RAO-3 algorithm improves the substation pf in the distribution system. The fuzzy multi-objective function is utilized for the two stages and simultaneous placements of the EVCS, DG, and DSTATCOM. The simulation results reveal that the simultaneous placement method performs better, due to the significant reduction in real power loss, improved voltage profile, and the optimum number of EVs. Moreover, the existing system performances for increased EV and distribution system loads are presented.

Impact of the Separation of the Continental Europe Power System on January 8, 2021 on the Work of the Bosnia and Herzegovina Power System

Abstract After the separation of the Continental Europe power system on 8th January 2021 in two synchronous zones, the electric power system of BiH (EPS BiH) shows a significant increase in frequency and voltages and oscillations of active and reactive power. The paper discusses the operation of protective devices in the BiH power system when the system was operating at high frequencies and voltages and had oscillations of active and reactive power. As a consequence of this behaviour in the EPS BiH there was activation of distance protections (DP) in substation (SS) 220/110 kV Prijedor 2 and overhead transmission lines (OHL) 220 kV Prijedor 2 - Međurić and OHL 220 kV Prijedor 2 – Sisak were disconnected. This was followed by activation of generator protections (reverse power protection and under-excitation protection) and outages of generator units in Hydro Power Plant (HPP) Salakovac, Thermal Power Plant (TPP) Kakanj, HPP Mostar, HPP Bočac, HPP Peć Mlini and HPP Jajce 2.

Modeling of application the FACTS devices on the example of power system of United Power System of Center

This paper considers installation of a flexible AC transmission system (FACTS) device on the 500 kV line of substation (SS) Belozerskaya - SS Vologodskaya of the United Power System of Center. Three FACTS devices in normal operation mode were modeled: a static reactive power compensator (STATCOM), a static synchronous series compensator, and a unified power flow control system. The obtained results are summarized in Table, which substantiates the choice of the best compensation for the Belozerskaya Vologodskaya line.

Modelling of emergency modes with FACTS devices installed

This paper considers installation of FACTS devices in a 500 kV line of substation (SS) Belozerskaya SS Vologodskaya. Three FACTS devices in emergency mode were modelled: a static reactive power compensator (STATCOM), a static synchronous series compensator, and a unified power flow control system. The parameters of MATLAB Simulink blocks were shown. The obtained results are summarized in Table, which substantiates the choice of the best device for the Belozerskaya - Vologodskaya line in emergency mode.

ANALISIS TEGANGAN LANGKAH DAN TEGANGAN SENTUH SERTA PERENCANAAN SISTEM PEMBUMIAN PADA PEMBANGUNAN SUBSTATION VVIP DI BANDAR UDARA INTERNASIONAL I GUSTI NGURAH RAI BALI

I Gusti Ngurah Rai International Airport Bali previously had a Substation (SS) D which serves the electrical system for the operation of modified Sewage Treatment Plant, however that substation currently under development with the construction of SS VVIP which serves the electrical system for the operation of VVIP buildings and Sewage Treatment Plant. To maintain the security of equipment and humans around the SS VVIP building a good grounding system is needed with a grounding resistance value of <1 Ohm. Because the land at Ngurah Rai Airport is sandy land, the suitable grounding systems are Pelat, Mesh, Grid-Rod groundinh systems [1]. To get an R value <1 Ohm, an analysis of each grounding system is needed, namely Pelat, Mesh, Grid-Rod.The results of the analysis showed that the safest system was the Grid-Rod grounding system with a grounding resistance value of 0.3718 Ohm, a touch voltage value of 223.51 Volt, a step voltage value of 1188.69 Volt and a planning cost of Rp7,712,500. Based on the construction planning data of the SS VVIP Ngurah Rai Airport, the grounding system used is the same as the result of the analysis of the Grid - Rod grounding system.

Selective‐tripping scheme for power supply arm on high‐speed railway based on correlation analysis between feeder current fault components in multisite

Auto‐transformer (AT) power traction networks with a parallel connection are the unique mode on high‐speed electric railways in China. The up line and down line of power traction networks are connected at substation (SS), AT post (ATP) and sectioning post (SP) through busbars, circuit breakers and disconnectors. Currently, when a fault occurs on power traction networks, the feeder line protection devices at the up line and down line in SS trip simultaneously. After that, the nonfault line and instantaneous fault line recover by means of autoreclosing. This tripping mode enlarges the power supply‐interrupted region. Based on the analysis of circuit networks of power traction networks on high‐speed electric railways, the interrelations of currents in SS and ATP and in SS and SP are derived. When a fault occurs on one side of the power traction networks, the feeder currents in ATP and SP flow from the nonfault side to the fault side. The relation between feeder currents in SS and ATP and between feeder currents in SS and SP reflect this characteristic. A criterion for discriminating the fault side and selective‐tripping scheme of breakers is proposed based on the correlation analysis of feeder current fault components in multisite. The simulation results show that this scheme can discriminate fault side and make a selective trip rapidly and correctly. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

연료전지 시스템을 이용한 전기철도 급전계통 전압강하 보상

In this paper, fuel cell power generation system that is being studied in recent railway field was applied to compensate for the voltage drop due to the load as driving electric vehicle. PSIM simulation program is to be used to implement the modeling of the electric railway for AC AT feeder system. For it, It was applied to the product-type single-phase PLL algorithm, step-down converter is controlled as power so as to have the fuelcell generation system.BR Based on it’s result, a reactive power due to the catenary impedance in accordance with the current flowing is compensated as linked with fuelcell generation system which supplied the current to the power supply grid. and then its performance was confirmed that voltage compensation effect obtained at SubStation (SS), SubSectioning Post (SSP), Sectioning Post (SP)

WSNs Power Consumption Reduction using Clustering and Multiple Access Techniques

Energy consumption is one of the important challenge in WSNs deployment and applications. This is because power of WSNs is limited by battery which is difficult if not impossible to replace or recharge in some manner in the sensor nodes. Power consumption can be controlled in WSNs in more than one layer. In this thesis, power efficiency problems and techniques of enlarging battery life using WSNs physical layer are investigated in the second layer MAC sublayer. The latter has been achieved using the multiple access techniques, TDMA and CDMA. Initially, the research attempt to divide the WSN nodes into clusters such that at any time only one specific cluster will operate and the remaining cluster switched off to reduce the power consumption. Each cluster consists of several nodes and one sub-station (SS), all the nodes in one cluster send its data to the (SS) that forwards the data to main station (MS). Furthermore, the link between nodes, SS, and MS is controlled and scheduled such that cluster and node switched to active or sleep modes. Four systems with multi-types of multiple access are proposed and tested. These systems are classified according to the way multiple access provided in the link: TDMA-TDMA-OFDM system, CDMA-CDMA system, CDMA-TDMA-OFDM system, and TDMA-OFDMTDMA-OFDM system. These systems have been simulated and investigated. By comparing the results of each system with different case of cluster, it has been found that the less consumed power is achieved with 8 clusters of 16 nodes/cluster case. The results also show that the best performance is achieved with CDMA-CDMA system with 8 clusters of 16 nodes/cluster case.

Estimation of Distribution Transformer Losses in Feeder Circuit

Losses of distribution transformers (DT) in a distribution system (DS) depend on mainly load. Actual measurement of these losses is in substation (SS) feeder circuit is not easy due to many inconveniences like difficulty in installation of meters, unfavourable locations and conditions. But as the DT losses are sizeable they need to be considered for overall loss calculations. In this paper, an approach is developed to estimate the DT losses in a feeder circuit. Losses of individual DTs are calculated and summed up to give the losses due to DT circuit. A sample case of a large power system is considered. The losses are calculated by the said approach. The overall DT circuit losses are 8.57% of the total import.

절연구간 자동통과 열차검지시스템 개발 및 성능시험

A neutral section is installed around feeding substation(SS) and sectioning post(SP) that M phase and T phase are isolated in AC feeding system. Electric Train under Notch-OFF is operated by inertia within the neutral section. It causes disturbing the operation of electric trains for speed drop and driver`s mistakes. A automatic changeover system with thyristor recently have taken under development. In the paper, it is introduced the configuration of train detection system and performance testing on automatic changeover system..