scholarly journals Impact of Network Reconfiguration: Case Study of Port-Harcourt Town 132/33kV Sub-transmission Substation and Its 33/11kV Injection Substation Distribution Networks

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Chinweike Innocent Amesi ◽  
Tekena Kashmony Bala ◽  
Anthony O. Ibe
Keyword(s):  
Power Flow ◽  
Low Voltage ◽  
Distribution Networks ◽  
Total Power ◽  
Base Case ◽  
Network Reconfiguration ◽  
Voltage Profile ◽  
Distribution Transformers ◽  
Port Harcourt ◽  
Bus Voltage

This paper examined the power flow status of the Port Harcourt Town (Zone 4) distribution networks to improve the performance. The network consists of 18 injection substations fed from 4 different sizes of transformers with a total power rating of 165 MVA, 132/33kV at the Port Harcourt Town sub-transmission substation. Gauss-seidel power flow algorithm was used to analyse the network in Electrical Transient Analyzer Program software (ETAP 12.6) to determine the various bus operating voltages, power flow, and over or under-loaded Transformers’ units. From the base-case simulation results obtained, it shows that these injection distribution transformers (PH Town 106.3%, RSU 90.5%, Marine Base 86.5%, UTC 87.9%, Nzimiro 89.5%, and Borokiri 88.7%) were overloaded on the network and the operating voltages observed for (PH Town 95.1%, RSU 83.0%, Marine Base 83.4%, UTC 82.8%, Nzimiro 85.2%, and Borokiri 82.1%) indicates low voltage profile. However, using network reconfiguration technique as proposed in this paper; there was reduction in the percentage loading of the said Transformers as it was upgraded to affect positively on its lifespan with (PH Town 44.1%, RSU 65.3%, Marine Base 60.7%, UTC 47.3%, Nzimiro 61.3%, and Borokiri 52.0%) loading,  and the bus voltage profiles was improved for (PH Town 100%, RSU 98.4%, Marine Base 98.8%, UTC 98.2%, Nzimiro 98.6%, and Borokiri 99.1%) with additional facilities. It is recommended that the power infrastructure facilities in Port Harcourt Town distribution network be immediately upgraded to reduce losses and improve the electricity supply to consumers. Also, in regard to these analyses, the sub-transmission substation requires 240 MW of power for effective power delivery.

scholarly journals Optimal Reconfiguration of Distribution Networks Using Hybrid Heuristic-Genetic Algorithm

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1544 ◽  
Author(s):  
Damir Jakus ◽  
Rade Čađenović ◽  
Josip Vasilj ◽  
Petar Sarajčev
Keyword(s):  
Distribution Network ◽  
Distribution Networks ◽  
Total Power ◽  
Computational Time ◽  
Small Scale ◽  
Network Reconfiguration ◽  
Optimal Distribution ◽  
Voltage Profile ◽  
Distribution Network Reconfiguration ◽  
Optimal Reconfiguration

This paper describes the algorithm for optimal distribution network reconfiguration using the combination of a heuristic approach and genetic algorithms. Although similar approaches have been developed so far, they usually had issues with poor convergence rate and long computational time, and were often applicable only to the small scale distribution networks. Unlike these approaches, the algorithm described in this paper brings a number of uniqueness and improvements that allow its application to the distribution networks of real size with a high degree of topology complexity. The optimal distribution network reconfiguration is formulated for the two different objective functions: minimization of total power/energy losses and minimization of network loading index. In doing so, the algorithm maintains the radial structure of the distribution network through the entire process and assures the fulfilment of various physical and operational network constraints. With a few minor modifications in the heuristic part of the algorithm, it can be adapted to the problem of determining the distribution network optimal structure in order to equalize the network voltage profile. The proposed algorithm was applied to a variety of standard distribution network test cases, and the results show the high quality and accuracy of the proposed approach, together with a remarkably short execution time.

scholarly journals Exploiting OLTC and BESS Operation Coordinated with Active Network Management in LV Networks

2020 ◽  
Vol 12 (8) ◽  
pp. 3332
Author(s):  
Konstantinos Kotsalos ◽  
Ismael Miranda ◽  
Jose Luis Dominguez-Garcia ◽  
Helder Leite ◽  
Nuno Silva ◽  
...  
Keyword(s):  
Power Flow ◽  
Optimal Power Flow ◽  
Low Voltage ◽  
Distribution Networks ◽  
Small Scale ◽  
Data Set ◽  
Economical Analysis ◽  
Distribution Transformers ◽  
Optimal Coordination ◽  
Battery Energy

The large number of small scale Distributed Energy Resources (DER) such as Electric Vehicles (EVs), rooftop photovoltaic installations and Battery Energy Storage Systems (BESS), installed along distribution networks, poses several challenges related to power quality, efficiency, and reliability. Concurrently, the connection of DER may provide substantial flexibility to the operation of distribution grids and market players such as aggregators. This paper proposes an optimization framework for the energy management and scheduling of operation for Low Voltage (LV) networks assuring both admissible voltage magnitudes and minimized line congestion and voltage unbalances. The proposed tool allows the utilization and coordination of On-Load Tap Changer (OLTC) distribution transformers, BESS, and flexibilities provided by DER. The methodology is framed with a multi-objective three phase unbalanced multi-period AC Optimal Power Flow (MACOPF) solved as a nonlinear optimization problem. The performance of the resulting control scheme is validated on a LV distribution network through multiple case scenarios with high microgeneration and EV integration. The usefulness of the proposed scheme is additionally demonstrated by deriving the most efficient placement and sizing BESS solution based on yearly synthetic load and generation data-set. A techno-economical analysis is also conducted to identify optimal coordination among assets and DER for several objectives.

scholarly journals Energy Loss Minimization by Optimal Siting and Sizing of DG with Network Reconfiguration in Distribution Networks

2019 ◽  
Vol 8 (10) ◽  
pp. 3621-3625
Keyword(s):  
Energy Loss ◽  
Distribution System ◽  
Power Loss ◽  
Reactive Power ◽  
Low Voltage ◽  
Distribution Networks ◽  
Network Reconfiguration ◽  
Voltage Profile ◽  
Loss Minimization ◽  
Power Loss Reduction

The main aim of the distribution system is delivery the power to the consumers. Because of, aging of electrical infrastructure, old control mechanism, increased power demand causing exploitation of the present electrical networks leads to low voltage profile, more active and reactive power loss with various power quality related issues causing poor network operation. In this method maximization of voltage profile with energy loss minimization is carried using network reconfiguration along with optimal siting of the distributed generation (DG). The proposed methodology is carried out on five bus system. The obtained results are impressive interms of voltage stability and power loss reduction.

scholarly journals Optimization of Energy Efficiency for Electric Power Distribution System Losses

2021 ◽  
Vol 9 (12) ◽  
pp. 934-940
Author(s):  
Okorie N. S.
Keyword(s):  
Energy Efficiency ◽  
Electric Power ◽  
Low Voltage ◽  
Distribution Network ◽  
Optimization Techniques ◽  
Power Network ◽  
Voltage Profile ◽  
Power Distribution System ◽  
Distribution Transformers ◽  
Port Harcourt

Abstract: This study evaluated the existing electric power network of Mile 2 Diobu zone, Port Harcourt distribution network which consists of four (4) 11kV distribution feeders namely; Ojoto, Nsukka, Udi and Silverbird. This work considered Ojoto and Nsukka Street distribution network for improved power quality. The three (3) 33/11kv injection substations are fed from 165 MVA transmission station (PH Town) at Amadi junction by Nzimiro. Collection and analysis of data collected from the injection substations that supply electricity to mile 2 Diobu, Port Harcourt was the first consideration. The distribution network was modeled in Electrical Transient Analyzer Program (ETAP) using Newton-Raphson Load Flow equations. The simulation result of the existing condition network shows that the network has low voltage profile problem on Nsukka network and overloading of distribution transformers on Ojoto networks. The following optimization techniques are applied: up-gradation of distribution transformers, and transformer load tap changer to improve the distribution network for Mile 2 Diobu, Port Harcourt electrical power network. The simulation result of the improved distribution network for Mile 2 Diobu, Port Harcourt power network shows that the voltage profile Nsukka network has improved within the statutory limit which is between 95.0 -105.0% and the loading of the distribution transformers on Ojoto and Nsukka networks are all below 70% required capacity. Keywords: Optimization, Energy Efficiency Distribution

scholarly journals Harmonic Analysis of Grid-Connected Solar PV Systems with Nonlinear Household Loads in Low-Voltage Distribution Networks

2021 ◽  
Vol 13 (7) ◽  
pp. 3709
Author(s):  
Syed Muhammad Ahsan ◽  
Hassan Abbas Khan ◽  
Akhtar Hussain ◽  
Sarmad Tariq ◽  
Nauman Ahmad Zaffar
Keyword(s):  
Low Voltage ◽  
Harmonic Distortion ◽  
Distribution Networks ◽  
Total Harmonic Distortion ◽  
Base Case ◽  
Solar Pv ◽  
Voltage Profile ◽  
Nonlinear Loads ◽  
Pv Systems ◽  
Pv Penetration

Grid-connected rooftop and ground-mounted solar photovoltaics (PV) systems have gained attraction globally in recent years due to (a) reduced PV module prices, (b) maturing inverter technology, and (c) incentives through feed-in tariff (FiT) or net metering. The large penetration of grid-connected PVs coupled with nonlinear loads and bidirectional power flows impacts grid voltage levels and total harmonic distortion (THD) at the low-voltage (LV) distribution feeder. In this study, LV power quality issues with significant nonlinear loads were evaluated at the point of common coupling (PCC). Various cases of PV penetration (0 to 100%) were evaluated for practical feeder data in a weak grid environment and tested at the radial modified IEEE-34 bus system to evaluate total harmonic distortion in the current (THDi) and voltage (THDv) at PCC along with the seasonal variations. Results showed lower active, reactive, and apparent power losses of 1.9, 2.6, and 3.3%, respectively, with 50% solar PV penetration in the LV network as the voltage profile of the LV network was significantly improved compared to the base case of no solar. Further, with 50% PV penetration, THDi and THDv at PCC were noted as 10.2 and 5.2%, respectively, which is within the IEEE benchmarks at LV.

scholarly journals Using Energy Storage Inverters of Prosumer Installations for Voltage Control in Low-Voltage Distribution Networks

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Storage System ◽  
Distribution Networks ◽  
Energy Storage System ◽  
Voltage Regulation ◽  
Active Power ◽  
Total Power

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.

scholarly journals Laplacian Matrix-Based Power Flow Formulation for LVDC Grids with Radial and Meshed Configurations

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1866
Author(s):  
Zahid Javid ◽  
Ulas Karaagac ◽  
Ilhan Kocar ◽  
Ka Wing Chan
Keyword(s):  
Fixed Point ◽  
Power Flow ◽  
Low Voltage ◽  
Mathematical Formulation ◽  
Distribution Networks ◽  
Load Flow ◽  
Banach Fixed Point Theorem ◽  
Loading Conditions ◽  
Flow Equations ◽  
Uniqueness Of The Solution

There is an increasing interest in low voltage direct current (LVDC) distribution grids due to advancements in power electronics enabling efficient and economical electrical networks in the DC paradigm. Power flow equations in LVDC grids are non-linear and non-convex due to the presence of constant power nodes. Depending on the implementation, power flow equations may lead to more than one solution and unrealistic solutions; therefore, the uniqueness of the solution should not be taken for granted. This paper proposes a new power flow solver based on a graph theory for LVDC grids having radial or meshed configurations. The solver provides a unique solution. Two test feeders composed of 33 nodes and 69 nodes are considered to validate the effectiveness of the proposed method. The proposed method is compared with a fixed-point methodology called direct load flow (DLF) having a mathematical formulation equivalent to a backward forward sweep (BFS) class of solvers in the case of radial distribution networks but that can handle meshed networks more easily thanks to the use of connectivity matrices. In addition, the convergence and uniqueness of the solution is demonstrated using a Banach fixed-point theorem. The performance of the proposed method is tested for different loading conditions. The results show that the proposed method is robust and has fast convergence characteristics even with high loading conditions. All simulations are carried out in MATLAB 2020b software.

scholarly journals Voltage regulation and power loss reduction by integration of SVC in distribution networks via PSSE

2020 ◽  
Vol 11 (3) ◽  
pp. 1579
Author(s):  
Ba-swaimi Saleh ◽  
Lee Jun Yin ◽  
Renuga Verayiah
Keyword(s):  
Power Flow ◽  
Voltage Stability ◽  
Flow Analysis ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Base Case ◽  
Facts Devices ◽  
Load Demand ◽  
Power Loss Reduction ◽  
The Stability

Voltage stability is necessary in order to maintain the health of the grid system. In recent years, the load demand is increasing from time-to-time which compromised the stability of the system. On that purpose, several methods on enhancing the voltage stability of the system was introduced such as the transformer tap and FACTS devices. In a general overview, this study is to propose a several power compensation techniques on the base case of an IEEE-33 bus whereby power flow analysis using Netwon- Raphson in PSS/E software is performed. Afterwards, distributed generation (DG) and Static VAR Compensator (SVC) will be implemented within the distribution network to compensate the voltage instability losses based on the weakest index from the bus system. From both the cases which is proposed earlier, a comparison study is conducted on the performance on both DG and SVC within the proposed network.

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