Journal ofRenewable Renewable Energy.
Electrical.
Computer Engineering Journal of Energy.
Electrical, and and Computer Engineering, 2 .
21-30 Vol.
No.
March 2022, 21-30 e-ISSN: 2776-0049 Research Original Article DOI: https://doi.
org/10.
29103/jreece.
Analysis of Load Flow and Short Circuit Against the Addition of Distributed Generation (DG) in Distribution Networks Ahmad RidwanA1.
Aejelina El Gazaly2.
Anang Tjahjono3 1 Dept.
of Electrical Engineering.
Universitas Medan Area.
Jl.
Kolam No.
Medan, 20223.
Indonesia, ahmadridwan@staff.
2 Dept.
of Electrical Engineering.
Universitas Andalas.
Kampus Limau Manih.
Padang, 25163.
Indonesia, elgazaly@gmail.
3 Dept.
of Electrical Engineering.
Politeknik Elektronika Negeri Surabaya.
Jl.
Raya ITS.
Kampus PENS.
Surabaya, 60111.
Indonesia, anang.
tj@pens.
Corresponding Author: ahmadridwan@staff.
id | Phone: 6282282857301 Received: February 21, 2022 Revision: March 15, 2022 Accepted: March 25, 2022 Abstract This study tries to determine the level of change in short-circuit fault currents on certain buses in the Andalas University distribution network due to the installation of a new generator.
Simulation of load flow and short circuit faults uses a 20 kV Andalas University distribution network system model to which a renewable generator with a capacity of 200 kW will be added.
The simulation results of the load flow on a 20 kV distribution system paralleled with DG show that the voltage drop is still in accordance with the provisions of PT.
PLN, this is due to the voltage drop in the distribution system is not up to 10% of the nominal 20 kV.
While the short circuit simulation results, the largest single-phase and three-phase short-circuit current values occur at the Nursing_P location of 9.
362 kA.
However, the short circuit capacity has not yet reached a maximum voltage of 20 kV 500 MVA or 14.
4 kA.
So that the amount of short circuit current contributed by Nursing_P is within normal limits and does not require additional equipment to protect the fault current.
Keywords: distributed generation.
load flow.
short circuit.
renewable energy Introduction The development of renewable energy and energy conversion needs to be done immediately due to the decline in fossil The decreasing production of petroleum fuels encourages people to play a role in developing and utilizing renewable energy sources and the world's readiness to reduce greenhouse gas emissions, which encourages the Government to continuously increase the role of new and renewable energy as part of maintaining energy security and Based on Government Regulation No.
79 of 2014 concerning National Energy Policy, where the target for the new and renewable energy mix is at least 23% in 2025 and 31% in 2050 (Wijaya et al.
, 2.
The use of electrical energy in large enough quantities for educational institutions such as campus buildings cannot avoid creating continuity of smooth activities, so it is necessary to add electrical energy from renewable energy sources.
The addition of renewable energy sources can be one of the alternative solutions for supplying electricity so that the demand for electrical energy can be met and save energy consumption from PT.
PLN (Syafii.
Zaini, et al.
, 2.
These renewable energy sources will later connect to other distribution networks, such as energy sources that do not pollute the environment and renewable environmentally friendly energy (Syafii.
Gazaly, et al.
, 2.
Distributed generation is a generator that is becoming popular because it provides several benefits (Mehigan et al.
, 2.
Renewable generators are sources of electrical energy that have a small capacity compared to existing sources of electrical energy and can be connected directly to the distribution network.
Distributed generation in distribution networks significantly improves network quality, such as improved voltage profile, increased reliability, and decreased power losses .
after adding distributed generation (Adajah et al.
, 2.
It has distributed generation sources such as gas turbines, photovoltaic cells, microturbines, wind generators, fuel cells, biomass, and other renewable energy storage systems.
In recent years photovoltaic (PV) and wind power generation have developed rapidly as one of the sources of distributed generation used (Musirikare et al.
, 2.
(Tjahjono et al.
, 2.
The current power system has expected to be a reliable and high-quality system, which means it has good quality and continuity does not harm living things and the surrounding environment (Arizaldi et al.
, 2.
The addition of new generators in the distribution network has a significant effect on improving the quality of the network.
The current is considerable and exceeds the nominal limit resulting in a short circuit that can cause damage to the electrical power system equipment (Dewi et al.
, 2.
The amount of short-circuit current depends on the type and location of the fault The more significant the short-circuit current, the more significant the impact.
Therefore, we need a system that can overcome the impact of these disturbances and also maintain the safety and reliability of the electric power system properly, and the system must be supported by an appropriate safety system so that disturbances can be isolated and continuity is maintained called a protection system.
This protection system will automatically separate the parts of the system that are affected by interference from the power system.
Circuit breakers, transducers, and relays are three parts Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 of the protection system.
Protection relays play an essential role in the operation of various power systems.
Relay coordination is an essential aspect of the design of a protection system because the coordination scheme must ensure fast, selective, and reliable relay operation to isolate the faulty part of the power system (H.
Zeineldin.
Hebatallah M.
Sharaf.
Doaa K.
Ibrahim, 2.
Relay protection is vital in overcoming the occurrence of short circuit faults.
The performance of the protection system needs to be improved, especially on the protection relay.
So to improve the performance, it is necessary to analyze the settings and coordination of the relay by describing the characteristic curve of the protection relay (Mehmed-Hamza & Stanchev, 2.
Problems encountered every time in the distribution system, such as if one of the feeders has a problem, can cause other feeders on the same bus to trip because a short circuit can trip up the relay on the incoming feeder.
In addition, it can also cause by a lack of coordination in relay settings between the outgoing substation and the express feeder supplying the substation, which also causes all outgoing feeders at the substation to blackout.
Literature Review Distributed Generation (DG) Distributed generation can be defined as small size generators operating in isolation or connected to an electrical distribution system(Hao et al.
, 2.
These generators may be conventional generators such as coal fuel, hydro-powered synchronous machines, as well as sources that include rapidly developing technologies such as photovoltaic, wind turbines, fuel cells and microturbines.
DG can bring advantages such as reducing system losses, increasing power quality and reliability (Aksoy & Nurolu, 2.
Distributed power generation based on renewable energy sources is becoming popular because it provides several benefits such as economic benefits with high efficiency, lower losses, as well as environmental benefits in reducing greenhouse gas emissions (Datta et al.
, 2.
(Abdel-Ghany et al.
, 2.
Due to the depletion of fossil fuels and environmental concerns about global warming, renewable energy sources have emerged as a new paradigm for meeting the energy needs of our society.
In recent years, electricity production from hydro, solar, wind, geothermal, tidal, wave and biomass energy sources has received increasing attention.
In 2012 electricity production from renewable energy sources worldwide exceeded 1470 gigawatts (GW) which represents about 19% of global energy consumption (Yaramasu et al.
, 2.
Single-Phase to Ground Short Circuit Fault A single-phase short-circuit to ground fault is a short circuit that occurs because the phase conductors and the ground are in contact with each other.
This single phase to ground short circuit fault often occurs in electric power distribution systems, the percentage of this fault is about 70% of other short circuit faults.
This disturbance is temporary, there is no permanent damage at the point of disturbance (Al qoyyimi et al.
, 2.
as shown in Figure 1.
Figure 1.
Single-Phase to Ground Short Circuit Fault To calculate the value of the total impedance (Z.
can use the equation:
Z = Z Z3 Z
Information: Z1 = Positive sequence impedance Z2 = Negative sequence impedance Z0 = Zero order impedance Two-Phase Short Circuit (Inter-Phas.
Fault Interphase short circuit .
ine to lin.
is a short circuit that occurs due to the contact of one phase conductor with another phase conductor, resulting in overcurrent .
ver curren.
Interphase short circuits can be caused by contacting the phase conductors due to tree branches blown by the wind.
The percentage of short circuit faults between phases is 15% as shown in Figure 2.
Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Figure 2.
Two-Phase Short Circuit (Inter-Phas.
Fault To calculate the value of the total impedance (Z.
can use the equation:
Z =
Z CZ
Information: Z1 = Positive sequence impedance Z2 = Negative sequence impedance Z0 = Zero order impedance Two-Phase to Ground Short Circuit Fault Two-phase short-circuit to ground fault is a short-circuit fault that occurs when two-phase lines or two-phase conductors are connected to ground.
The percentage of two-phase short circuit to ground fault occurs is 10% as shown in Figure 3.
Figure 3.
Two-Phase to Ground Short Circuit Fault To calculate the value of the total impedance (Z.
can use the equation:
Z =
Z CZ 3
Z Z
Information: Z1 = Positive sequence impedance Z2 = Negative sequence impedance Z0 = Zero order impedance Three-Phase Short-Circuit Fault Three-phase short-circuit fault is a short-circuit fault that occurs due to the contact of the three phase conductors, this disturbance can be caused by a tree falling which then hits the phase wire, thereby breaking the phase wire The percentage of occurrence of this short circuit is 5%.
The three-phase short-circuit fault can be seen in Figure 4.
Figure 4.
Three-phase short-circuit fault To calculate the value of the total impedance (Z.
can use the equation:
Z =Z
Information: Z1 = Positive sequence impedance Three-Phase To Ground Short Circuit Fault Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Three-phase short-circuit fault to ground is a short-circuit fault that occurs due to the contact of the three phase conductors and is connected to ground.
The percentage of three-phase short circuit to ground fault is 5%.
Three-phase short circuit to ground can be seen in Figure 5.
Figure 5.
Three-Phase to Ground Short Circuit Fault To calculate the value of the total impedance (Z.
can use the equation:
Z =Z Z
Information: Z1 = Positive sequence impedance Z0 = Zero order impedance Materials & Methods Distribution Network Specification In this study, the data used for load flow analysis with Solar Power Plant and Wind Power Plant on the Andalas University voltage power network.
Then the primary data used consists of load data and transformer data.
The distribution network of Unand has nine units of transformers with different capacities according to the needs of each faculty on the Andalas University campus.
The data of the transformer and its capacity are as shown in Table 1.
Loading data take when there is a peak electrical load.
Table 1.
Data Transformer In Distribution Network Transformer Name Capacity .
VA) Faculty of Engineering Faculty of Mathematics and Natural Sciences Faculty of Agriculture PKM Faculty of Animal Husbandry Faculty of Social Sciences Faculty of Nursing Faculty of Medicine Andalas University Hospital Furthermore, load data on the Andalas University electricity distribution network system is also needed in this The load data and its capacity can be seen in Table 2.
Table 2.
Load Data on Distribution Network Bus ID Engineering Mathematics and Natural Sciences Animal Husbandry Social Sciences Agriculture Nursing PKM Andalas University Hospital Medicine Total kVar In this study, the distribution network system of Andalas University 20 kV consists of 21 buses with a single line diagram model in Figure 6.
Meanwhile, when the condition of the Andalas University distribution network system is paralleled with a DG of 200 kW.
The DG used in this study these are the Solar Power Plant and the Wind Power Plant.
Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Figure 6.
Single Line Diagram of 20 kV Distribution Network System Andalas University Research Steps This research begins with a literature study which is used as a guide in conducting research.
Furthermore, collecting data containing a 20kV distribution network system connected to the Andalas University network system.
Then make a single line diagram circuit modeling.
After the single line diagram modeling has been completed, then the next step is to simulate load flow testing and short circuit testing on the system with the addition of DG as shown in Figure 7.
Figure 7.
Research Flowchart Load Flow Analysis and Short Circuit with the Addition of Distributed Generation Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Results and Discussion Load Flow Study Before Adding Distributed Generation (DG) 200 kW In this load flow study simulation, it will be checked whether the voltage conditions along the distribution network of Andalas University are sufficient to parallel the electrical energy with DG at a predetermined interconnection point.
The results of this simulation are shown in Table 3.
Table 3.
Voltage Conditions at GH and Buses in Andalas University's 20 kV System Before Parallel with DG 200 kW Measuring Point Voltage Condition Information Bus 20 kV GH 19,973 kV Qualify Nursing_P 19,951 kV Qualify Animal Husbandry_P 19,935 kV Qualify Agriculture_P 19,932 kV Qualify At the Connecting Point 19,965 kV Qualify Mathematics and Natural Sciences_P 19,929 kV Qualify PKM_P 19,933 kV Qualify Social Sciences_P 19,95 kV Qualify Medicine_P 19,969 kV Qualify At the Connecting Point 19,966 kV Qualify Based on the simulation results in Figure 8, it can be concluded that the voltage value in the distribution system of 20 kV Andalas University before paralleling with DG 200 kW is in accordance with the provisions of PT.
PLN (Perser.
that it can be done in parallel with DG because the voltage drop is not up to 10% of the nominal 20 kV.
Figure 8.
Andalas University 20 kV Distribution System Before Parallel with DG 200 kW Load Flow Study After Adding Distributed Generation (DG) 200 kW The simulation of load flow studies on the distribution network of Andalas University after being parallel with the 200 kW (DG) Wind Power Plant and Solar Power Plant aims to examine the operating conditions of the system.
The results of the simulation of the operating conditions of the system are shown in Table 4.
Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Table 4.
Voltage Conditions on GH and 20 kV System Buses at Andalas University After Parallel with 200 kW DG Measuring Point Voltage Condition Information Bus 20 kV GH 19,97 kV Qualify Nursing_P 19,95 kV Qualify Animal Husbandry_P 19,94 kV Qualify Agriculture_P 19,93 kV Qualify At the Connecting Point 19,97 kV Qualify Mathematics and Natural Sciences_P 19,93 kV Qualify PKM_P 19,93 kV Qualify Social Sciences_P 19,95 kV Qualify Medicine_P 19,97 kV Qualify At the Connecting Point 19,97 kV Qualify Based on the simulation results in Figure 9, it can be concluded that the voltage value when the condition of the 20 kV distribution system of Andalas University is parallel with the Solar Power Plant and the 200 kW Wind Power Plant is in accordance with the provisions of PT.
PLN (Perser.
So that the 20 kV distribution system of Andalas University can be operated because the voltage drop is not up to 10% of the nominal 20 kV.
Table 5.
Comparison of Voltage Conditions of 20 kV Distribution System Andalas University Before and After Parallel With DG 200 kW (Solar Power Plant.
Wind Power Plan.
Voltage .
V) Information Load Point Grid (Solar Power Plant and Wind Power Plan.
Bus 20 kV GH 19,973 kV 97 kV Qualify Nursing_P 19,951 kV 95 kV Qualify Animal Husbandry_P 19,935 kV 94 kV Qualify Agriculture_P 19,932 kV 93 kV Qualify At the Connecting Point 19,965 kV 97 kV Qualify Mathematics and Natural Sciences_P 19,929 kV 93 kV Qualify PKM_P 19,933 kV 93 kV Qualify Social Sciences_P 19,95 kV 95 kV Qualify Medicine_P 19,969 kV 97 kV Qualify At the Connecting Point 19,966 kV 97 kV Qualify In table 5 is a comparison of the voltage on the distribution system of 20 kV Andalas University before and after parallel with DG 200 kW.
The results show that after the installation of the 200 kW DG the distribution system can still be operated, because the difference is not too significant and still meets the requirements as shown in Figure 9.
Voltage Condition .
V) Comparison of Voltage Conditions of 20 kV Distribution System Before and After Parallel DG
19,98
19,97
19,96
19,95
19,94
19,93
19,92
19,91
Voltage Condition Before Parallel with DG Voltage Condition After Parallel with DG Figure 9.
Comparison of Voltage Conditions of 20 kV Distribution System Before and After Parallel with DG Based on Figure 9, it can be seen that the voltage conditions before and after parallel with the DG 200 kW Solar Power Plant and the Wind Power Plant with a 20 kV system at Andalas University are up and down.
Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Short Circuit Study Before Addition of Distributed Generation (DG) 200 kW In the short circuit study simulation, it will be checked whether the short circuit fault current condition along the Andalas University electricity distribution network does not spike high when it will be paralleled from electrical energy to DG at a predetermined interconnection point or not.
The simulation results of the short circuit study are shown in Table 6.
Table 6.
Three-Phase Short Circuit Fault Current Conditions at Three Fault Locations in Andalas University 20kV System Buses Before Parallel with DG Disturbance Location Three Phase Fault (KA) Information Nursing_P 8,495 Secure Mathematics and Natural Sciences_P 7,001 Secure Animal Husbandry_P 6,05 Secure Based on the results of the short circuit simulation, it can be concluded that the value of the fault current in the distribution system of 20 kV Andalas University before paralleling with DG is in accordance with the provisions of the Regulation of the Minister of Energy and Mineral Resources concerning the regulation of electricity distribution (Distribution Cod.
in 2009 determined short circuit capacity equipment voltage 20 kV maximum 500 MVA or 14.
4 kA.
So there is no need to add a security system or protection system at the fault location as shown in Figure 10.
Figure 10.
Three-Phase Circuit Fault Current Conditions in Andalas University 20 kV System Before Parallel DG Short Circuit Study After Addition of Distributed Generation (DG) 200 kW Short circuit simulation on the distribution system of Andalas University with parallel DG 200 kW aims to check the operating conditions of the system when DG is parallel.
Then the goal is also as a plan for a security system in the distribution system.
The simulation results are shown in Table 7.
Table 7.
Three Phase Short Circuit Fault Current Condition in Andalas University 20 kV System After Parallel with Three Phase Fault (KA) Disturbance Location Before Parallel After Parallel Information Nursing_P 8,495 9,362 Secure Mathematics and Natural Sciences_P 7,001 7,049 Secure Animal Husbandry_P 6,051 7,997 Secure After simulating the short-circuit fault on the Andalas University 20 kV distribution network with the addition of a renewable generator, the short-circuit current value at each fault point can be seen in table 8.
Journal of Renewable Energy.
Electrical, and Computer Engineering, 2 .
21-30 Table 8.
Comparison of Short Circuit Fault Results in 20 kV Distribution Network Andalas University with the addition of DG Three Phase Fault Phase to phase Single Phase to Disturbance Location (KA) (KA) fault Ground Fault (KA) Nursing_P 9,362 8,105 8,512 Mathematics and Natural Sciences_P 7,048 6,103 6,058 Animal Husbandry_P 7,997 6,923 7,012 Based on the short circuit simulation results in Table 8, the largest 1 phase and 3 phase short circuit current values occur at the Nursing_P location of 9,362 kA.
Based on the Regulation of the Minister of Energy and Mineral Resources concerning the rules for the distribution of electricity (Distribution Cod.
in 2009 it is determined that the short-circuit capacity of 20 kV voltage equipment is a maximum of 500 MVA or 14.
4 kA.
So that the magnitude of the short circuit current at the Nursing_P location is within normal limits and no additional equipment is needed to protect the fault current .
Conclusions Based on the simulation results, the short-circuit current capacity obtained has a good influence on the Andalas University network system with the addition of distributed generation.
So that with this research the addition of new generators can be an alternative source of electricity supply so that the demand for electrical energy can be fulfilled and can also save energy consumption from PT.
PLN (Perser.
Acknowledgments You may wish to thank those who have supported you and your work.
Personal acknowledgements will be limited to appropriate professionals who contributed to the paper, including technical assistance and/or financial material References