Analysis and Research of Three-phase Unbalance in Distribution Transformers

Pan, Benren; Zhang, Yan; Gui, Xiaozhi; Wan, Yong; Wang, Guannan

doi:10.1088/1755-1315/252/3/032196

Cited by 6 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Figure 1, the common point to which all the loads are connected is assumed to be solidly grounded, i.e., without a differential potential with respect to the neutral point at the terminals of the substation (this implies that 𝕍 𝑛𝑜 = 0). Thus, each phase current can be calculated as defined from (2) to (4).…”

Section: The Three-phase Power Flow Problemmentioning

confidence: 99%

“…The general structure of electrical distribution networks has three phases, i.e., three conductors -phases a, b, and c -are used to efficiently distribute energy. Under balanced operating conditions, these networks are very efficient, as they ensure the lowest possible energy losses [4], [5]. Nevertheless, the real nature of electrical networks is unbalanced, given that (i) the distribution transformers that interface energy users and the grid have single-, two-, and three-phase connections [6], [7]; (ii) due to the length of the feeders, grid construction does not apply the concept of transposition, which is typically used in transmission networks [8]; and (iii) the electrical behavior of each node's users is not balanced, which implies that different current levels are requested per phase [9].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Power Losses Reduction in Three-Phase Unbalanced Distribution Networks Using a Convex Optimization Model in the Complex Domain

Montoya-Giraldo,

Ramírez-Vanegas,

González-Granada

2024

TecnoL.

View full text Add to dashboard Cite

This article presents a solution methodology to minimize power losses in three-phase unbalanced distribution networks. This approach involved an efficient complex-domain model that is categorized under mixed-integer convex optimization. The methodology employed consisted of efficient load rotation at each constant power node via a three-phase rotation matrix that allows defining each load connection to minimize the expected power imbalance at the terminals of the substation, as well as the total grid power losses, and improve voltage profile performance at each system phase. The load imbalance, expressed as a percentage, can be defined as a function of the active, reactive, or apparent power. In addition, considering the complex-domain representation of three-phase electrical networks under steady-state conditions, a mixed-integer convex model was formulated to reduce the power imbalances. With the purpose of determining the initial and final power losses of these distribution systems, the successive approximations method was employed to address the three-phase power flow problem. As a result, numerical validations in the IEEE 25-bus system and a 35-node three-phase feeder showed that the final active power losses vary depending on the objective function analyzed. Therefore, for the test feeders studied, it is necessary to evaluate each objective function, with the aim of finding the one that yields the best numerical results. Power losses reductions of about 3.8056 % and 6.8652 % were obtained for both test feeders via the proposed optimization methodology. All numerical validations were performed in the Julia programming environment, using the JuMP optimization tool and the HiGHS solver.

show abstract

Section: The Three-phase Power Flow Problemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Power Losses Reduction in Three-Phase Unbalanced Distribution Networks Using a Convex Optimization Model in the Complex Domain

Montoya-Giraldo,

Ramírez-Vanegas,

González-Granada

2024

TecnoL.

View full text Add to dashboard Cite

show abstract

“…Besaran nilai dari arus netral dapat mengukur dampak yang terjadi pada jaringan distribusi [14]. Ketidakseimbangan beban ini menyebabkan serangkaian kerugian salah satunya rugirugi daya, sehingga perlunya penanganan terhadap ketidakseimbangan beban pada transformator distribusi [15]. Konfigurasi yang buruk sangat berpengaruh terhadap keandalan dan efisiensi sehingga menyebabkan peningkatan dari rugi-rugi daya [16].…”

Section: Pendahuluanunclassified

Evaluasi Ketidakseimbangan Beban pada GTT 20kV terhadap Arus Netral dan Rugi Daya

Wicaksono,

Wrahatnolo

2023

JJEEE

View full text Add to dashboard Cite

Batas ketidakseimbangan pembebanan pada Sistem Distribusi Tenaga Listrik ditetapkan yakni antara 5 – 20 % terhadap beban per fasa. Hal ini terjadi akibat pertumbuhan beban yang tidak merata sehingga menyebabkan ketimpangan antara masing – masing fasa. Persentase ketidakseimbangan beban ini berpengaruh terhadap besarnya nilai arus yang mengalir pada penghantar netral. Sehingga netral tersebut dapat menyebabkan rugi - rugi daya pada transformator distribusi. Penelitian ini yang dilakukan pada penyulang plumbungan diantaranya transformator distribusi RB877 memiliki persentase 64,1% dan RB876 memiliki persentase 21% terhadap ketidakseimbangan beban. Sehingga persentase tersebut diluar batas yang telah ditetapkan oleh standar. Dalam hal ini, penelitian dilakukan dalam rangka meperbaiki rugi – rugi daya yang timbul pada transformator distribusi RB877 sebesar 0,214 kW dan RB876 sebesar 0,025 kW dengan melakukan penyeimbangan beban terhadap masing – masing fasa. Simulasi Aliran Daya Tak Seimbang pada ETAP 19.0 digunakan dalam menyelesaikan masalah dalam penelitian ini. Berdasarkan hasil simulasi, persentase ketidakseimbangan beban transfomator distribusi RB877 menjadi 1,16% dan RB 876 menjadi 4,2%. Penyeimbangan yang dilakukan dengan membagi ketimpangan yang terjadi pada fasa yang memiliki kapasitas lebih besar ke yang lebih kecil mengakibatkan penurunan pada arus netral yang semula pada transformator distribusi RB877 sebesar 25,05 A menjadi 1,8 A dan pada RB876 yang semula 8,77 A menjadi 0,8 A. Dengan begitu, rugi daya yang timbul pada akan menurun yaitu transformator distribusi RB877 sebesar 0,00021 kW dan RB876 sebesar 0,0011 kW.The limit of load imbalance in the Electric Power Distribution System is set between 5%-20% of the load per phase. This occurs due to uneven load growth that causes inequality between each phase. The percentage of load imbalance affects the value of the current flowing in the neutral conductor. So that the neutral will cause power loss in the distribution transformer. This research was conducted on the plumbungan extension, including the RB877 distribution transformer which has a percentage of 64.1% and RB876 has a percentage of 21% of the load imbalance. So that the percentage is outside the limit set by the standard. In this case, research was conducted in order to improve the power losses arising in the RB877 distribution transformer of 0.214 kW and RB876 of 0.025 kW by balancing theload on each phase. Unbalanced Load Flow Simulation in ETAP 19.0 is used in solving the problems in this study. Based on the simulation results, the percentage of load imbalance of distribution transfomator RB877 becomes 1.16% and RB 876 becomes 4.2%. Balancing carried out by dividing the imbalance that occurs in the phase that has a larger capacity to the smaller one results in a decrease in the neutral current which was originally in the RB877 distribution transformer of 25.05 A to 1.8 A and in RB876 which was originally 8.77 A to 0.8 A. Thus, the power losses arising will decrease, namely the RB877 distribution transformer of 0.00021 kW and RB876 of 0.0011 kW.

show abstract

“…Experiences in the electrical field as revealed that unequal sharing of single phase loads among the three supply phases, which may also frequently vary is one of the major causes of unbalance [9] Current unbalance is the value of the current flowing in each different phase of the electric power system. In general, current unbalance is caused by uneven load distribution which can be done with load balancing [10].…”

Section: Unbalance Current and Voltagementioning

confidence: 99%

Evaluation and Mitigation of Voltage and Current Unbalance at MSTP Undip Jepara

Denis

Sinuraya

Soemantri

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Marine Science Techno Park (MSTP) Diponegoro University is a central for the application of technology and research in the fisheries and marine sector under the auspices of Diponegoro University. After measuring the electrical power quality parameters, a voltage and current unbalance problem was found on each SDP and MDP at MSTP Undip Jepara Building. The final project is designed to mitigate current and voltage unbalance with a load equalization method in each phase using ETAP 12.6 software. According to the ANSI C84.1-1995 standard, the maximum current unbalance value is 5% and according to the IEEE 45-2002 standard, the maximum voltage unbalance value is 3%. The equalization results show that the load can decrease the value of current unbalance, voltage unbalance, and neutral current that already meets the standards. Based on the evaluation of existing conditions, the current unbalance value on the MDP decreased from 21.522% to 0.419%, the MDP bus voltage unbalance value decreased from 0.280% to 0.015%, and the neutral current decreased from 35.5 ampere to 1 ampere.

show abstract

Analysis and Research of Three-phase Unbalance in Distribution Transformers

Cited by 6 publications

References 5 publications

Power Losses Reduction in Three-Phase Unbalanced Distribution Networks Using a Convex Optimization Model in the Complex Domain

Power Losses Reduction in Three-Phase Unbalanced Distribution Networks Using a Convex Optimization Model in the Complex Domain

Evaluasi Ketidakseimbangan Beban pada GTT 20kV terhadap Arus Netral dan Rugi Daya

Evaluation and Mitigation of Voltage and Current Unbalance at MSTP Undip Jepara

Contact Info

Product

Resources

About