Defence Scheme on Madura Island Against System Loading

Variation for Energy Security

Novian Patria Uman Putra

, Titiek Suheta

, Nasyith Hananur Rohiem

, Trina Wati

D. M. Ariyanto and Lestarina Tampubolon

Electrical Engineering Department, Institut Teknologi Adhi Tama Surabaya,

Jl. Arif Rahman Hakim no.100, Surabaya, Indonesia

Keywords: Defence Scheme, Overload Shedding, Overcurrent Relay, Energy Security.

Abstract: One of the obstacles that often occurs in the distribution system is overloading. It happens because of the high

demand for consumer expenses or the criteria of N-1 in the distribution system not being met. In other words,

when there is a disturbance in one of the conductors in the electric power distribution system, the other

conductor will experience overloading (above the nominal). Therefore, the Defence Scheme must be

implemented as it serves as a defence strategy that aims to maintain or restore the system to a normal state

and prevent widespread blackouts and for energy security. The implementation of the defence scheme

happened at the Ujung-Bangkalan Bay Line by adding safety equipment, namely an Overload Shedding

(OLS) relay. The work of Overload Shedding Relay (OLS) was coordinated with the Overcurrent Relay

(OCR). OLS and OCR would be simulated using the DigSILENT. The result of the simulation demonstrated

the coordination between OLS and OCR during the overloading execution. The simulation was carried out

based on the distribution data through the Ujung-Bangkalan conductor. When the OLS failed to work, it would

activate the OCR for the Ujung-Bangkalan conductor so that the Ujung-Bangkalan electricity supply was cut

off and the blackouts spread.

1 INTRODUCTION

Using Security in the distribution of the electric

power system is very important. The fulfillment of the

N-1 criteria in the distribution system is of greater

concern. In a sense, if there is a disturbance in one of

the conductors of the distribution system of the

electric power system, there will be an overload on

the other conductor (Anung & Achirul Ramadhani,

2017). The implementation of the defense scheme on

the electricity system on Madura Island is carried out

by coordinating the work of the overload shedding

(OLS) relay against the overcurrent relay (OCR).

OLS will play a role in securing equipment from

overload so that it can minimize the occurrence of

widespread blackouts. The application of the OLS

relay at the Ujung Substation is critical in order for

https://orcid.org/0000-0001-9027-4707

https://orcid.org/0000-0001-9450-3140

https://orcid.org/0000-0001-8431-1911

the OLS relay to work first rather than the short

circuit safety relay like Over Current Relay (OCR)

when the electric power distribution line towards

Madura Island is overloaded. OLS is expected to be

able to select priority loads and determine the load to

be released to prevent widespread blackouts.

Therefore, the OLS and OCR settings must be

coordinated to secure interference(U. Induk et al.,

2020).

2 METHODOLOGY

In the system, for the implementation of a defense

strategy for the operation of the electric energy

system, which aims to maintain or restore the system

to normal operating limits and prevent widespread

210

Putra, N., Suheta, T., Rohiem, N., Wati, T., Ariyanto, D. and Tampubolon, L.

Defence Scheme on Madura Island Against System Loading Variation for Energy Security.

DOI: 10.5220/0012114800003680

In Proceedings of the 4th International Conference on Advanced Engineering and Technology (ICATECH 2023), pages 210-214

ISBN: 978-989-758-663-7; ISSN: 2975-948X

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

disturbances and even blackouts, the Defense Scheme

function is used when a disturbance occurs that has

the potential to hamper system stability.

The purpose of the defense scheme is to maintain

system supply (500/150 kV conductors and IBT) in

order to survive abnormal conditions caused by

disturbances in electrical equipment, prevent

widespread disturbances, and save thermal generators

with the aim of avoiding expensive start-up costs and

speeding up the recovery process.

2.1 Overload Shedding (OLS)

Overload Shedding is an important concept in the

defense scheme strategy's implementation, as OLS

works when there is an overload condition when

setting a time period on electrical equipment. The

working principle of OLS is to release the load

gradually and automatically so that the equipment

does not experience blackouts and can return to

operation below its nominal value (U. Induk et al.,

2020).

One of the disturbances that can cause overcurrent

is overload. Therefore, the Over Load Shedding

(OLS) setting will be coordinated with the Over

Current Relay (OCR) setting in the 20 kV Incoming

Transformer. As a result, when the PMT disconnects,

the error does not occur during discharge and there is

an indication of the working relay (A. A. S. P.

Larekeng & M. Iqbal, 2020; Anung & Achirul

Ramadhani, 2017; A.W Hidayat, 2013; E. Pafela &

E. Hamdani, 2016; I. Hajar & M. Ridho, 2020; T.

Nova, 2013).

Figure 1: Load Shedding Scheme with OLS.

When there is an overload, OLS will reduce the load

by tripping the target according to what has been set

on the OLS relay(Anung & Achirul Ramadhani,

2017). OLS works in three stages, and each stage has

a different trip time. If OLS fails to work, then OCR

will work and trip the line it protects

2.2 Over Current Relay (OCR)

Overcurrent relays(T. Nova, 2013) can be said to be

equipment whose function is to sense when there is

an overcurrent caused by a short circuit or an overload

that can damage equipment in the protected area. As

for the ground fault relay, it will detect if there is a

short circuit to ground. The single-line diagram (T.

Nova, 2013) of the relay is as follows:

Figure 2: Single Line OCR and GFR.

2.3 Current and Time Setting on OCR

and OLS

The formula for setting current and OCR times is

found in equations (1) and (2). Then, in equations (3)

and (4), the current and time formula for OLS

coordinated with OCR is found. The calculation of

OLS

(Anung & Achirul Ramadhani, 2017)

(T.

Nova, 2013)

and OCR(T. Nova, 2013) is based on the

calculation of SPLN T5.002-1:2010 as follows:

• Current Setting OCR

𝐼𝑠  1.2 ∗ 𝐼𝑛 (1)

Wherein :

Is = Current Setting for OCR (Ampere)

In = The smallest nominal current in a conductor

(Ampere)(SPLN T5.002-1:2010 Standar

Pola Proteksi, 2010)

• Time Setting OCR

𝑇𝑀𝑆 

/

.



.

∗𝑇𝑆𝐼 (2)

Wherein :

TMS = Time Multiple Setting

If = Short Circuit Current

Is = Current setting

T(SI)= Working Time Relay (Value 1)(PT. PLN

(Persero), 2010)

Defence Scheme on Madura Island Against System Loading Variation for Energy Security

211

• Current Setting OLS

𝐼𝑠  1.1 ∗ 𝐼𝑛 (3)

Wherein :

Is = Current Setting for OCR (Ampere)

In = The smallest nominal current in a conductor

(Ampere)(PT. PLN (Persero), 2010)

• Time Setting OLS

For setting the time used in the OLS relay, it

uses definite time characteristics and has a

gradual setting time

(U. Induk et al., 2020).

Figure 3: Subsystem 150 kV Ujung – Bangkalan.

3 EAST JAVA REGIONAL 4

DEFENCE SCHEME SETTINGS

DATA

In order to optimize the load-shedding mechanism,

the OLS scheme is created in stages. Overload

Shedding (OLS) GI Edge works in 3 stages. These

three stages will extinguish the target, namely the

transformer on the island of Madura.

a) For Stage 1, with a working current of 710 A,

the working rate of 5 seconds opens:

• PMT 20 kV Incoming Transformer–2 150/20

kV GI Bangkalan (ON/OFF)

b) For Stage 2, with a working current of 710 A,

the working rate of 5.5 seconds opens:

• PMT 20 kV Incoming Transformer–2 150/20

kV GI Sampang (ON/OFF)

• PMT 20 kV Incoming Transformer–2 150/20

kV GI Sumenep (ON/OFF)

c) For Stage 3 with a working current of 710 A, the

working rate of 6 seconds opens:

• PMT 20 kV Incoming Transformer–1 150/20

kV GI Bangkalan (ON/OFF)

• PMT 20 kV Incoming Transformer–1 150/20

kV GI Sampang (ON/OFF)

• PMT 20 kV Incoming Transformer–1 150/20

kV GI Sumenep (ON/OFF) [3].

4 SIMULATION RESULTS

In this section, we will see a simulation of the

Defence Scheme on Madura island with variation

load as shown to the table 1 below

Table 1: Setting OCR and OLS

Settin

I (Ampere)

OCR 760 0.53 SI

OLS Sta

e 1 710 5.00 DT

OLS Sta

e 2 710 5.50 DT

OLS Sta

e 3 710 60 T

OCR must be faster than OLS during a short circuit

current fault. However, during overload disturbances,

OLS must work faster than OCR.

Table 2: Calculation data for Bangkalan Bay OCR settings

in Ujung GIS.

xI>

I (Amp.) t (second)

Primary Secondary Calculated

1,5 1140 5,7 9,11

2 1520 7,6 5,32

2,4 1824 9,12 4,2

3 2280 11,4 3,34

3,5 2660 13,3 2,92

4 3040 15,2 2,64

The following in Figure 4 below shows the voltage

graph data on each bus

Figure 4: Ujung-Bangkalan OLS and OCR Coordination

Curve.

ICATECH 2023 - International Conference on Advanced Engineering and Technology

212

Description

: Current

: OCR

: OLS Stage 3

: OLS Stage 2

: OLS Stage 1

X-Axis : Current Values

Y-Axis : Relay Working Time

Table 3: OCR and OLS Relay Performance Data.

Working

Current

686,05 744,9 744,9 744,9 1826,97

OCR

T(s)

Calc ~ ~ ~ ~ 4,193

Sim 10000

9999,9 9999,9 9999,9

4,217

OLS

T(s)

Std ~ 5 5,5 6 -

Sim 10000 5 5,5 6 -

OLS

- T1 T2 T3

Condition 0 1 2 3 4

Description

T1 : PMT 20 KV Trafo 2 GI Bangkalan

T2 : PMT 20 KV Trafo 2 GI Sampang, PMT 20

KV Trafo 2 GI Sumenep

T3 : PMT 20 KV Trafo 1 GI Bangkalan,

PMT 20 KV Trafo 1 GI Sampang,

PMT 20 KV Trafo 1 GI Sumenep

0 : Normal

1 : OLS Stage 1

2 : OLS Stage 2

3 : OLS Stage 3

4 : OLS Not Working

The effect of OLS work on the load on Madura Island

is to prevent widespread blackouts due to overloading

by extinguishing some of the load using OLS. The

load that was extinguished based on the data of the

UP2B defense scheme, namely

• At Stage 1, turn off the load. The target of OLS

phase 1 is PMT 20 kV Incoming Transformer-2

150/20 kV GI Bangkalan. The total load that was

extinguished was 18.4 MW.

• Turn off the load at Stage 2. The target of OLS

phase 2 is PMT 20 kV Incoming Transformer-2

150/20 kV GI Sampang and PMT 20 kV Incoming

Transformer-2 150/20 kV GI Sumenep. The total

load that was extinguished was 78 MW.

• Turn off the load at Stage 3. The targets of OLS

phase 3 are PMT 20 kV Incoming Transformer-1

150/20 kV GI Bangkalan, PMT 20 kV Incoming

Transformer-1 150/20 kV GI Sampang, and PMT

20 kV Incoming Transformer-1 150/20 kV GI

Sumenep. The total load that was extinguished

was 81.9 MW.

Table 4: OLS SUTT 150 kV Load Shedding Ujung-

Bangkalan.

Tahap Total Beban (MW)

1 18,4

278

3 81,9

5 CONCLUSION

Based on the results of the analysis and simulation in

this thesis research, it can be concluded:

1. The operation of OCR and OLS relays in terms of

calculations and simulations is in accordance with

the standard calculation provisions regulated by

PLN.

2. The coordination of OLS and OCR relays in

securing the distribution system has gone well,

where OLS works first to secure overload by

using 3 stages. The OLS setting is smaller than the

OCR setting in order to prevent OCR from

working before OLS. OLS stages are

distinguished based on the working time. OLS

works within 5 DT for the first stage, 5.5 DT for

the second stage, and 6 DT for the third stage. And

for OCR working time using standard inverse

characteristics, namely working time based on the

value of the current flowing, the greater the value

of the current flowing, the faster the relay works.

3. OLS works according to the calculation of the

setting value, which is 710 A, but when OLS fails

to reduce the overload, the OCR relay will work,

where the current OCR working setting at Bay

Bangkalan GIS Ujung is 760 A.

OLS has an effect on reducing excessive loads,

namely by extinguishing the load according to the

OLS target to prevent widespread blackouts.

REFERENCES

A. A. S. P. Larekeng, & M. Iqbal. (2020). Analisis kinerja

over current relay (ocr) & ground fault relay (gfr) pada

sistem 20 kv ultg maros menggunanakan alat uji cmc

356.

Anung, & Achirul Ramadhani. (2017). Penerapan ols untuk

meminimalisir pemadaman meluas akibat overload

pada satu penghantar. Jurnal Isu Teknologi, 12(1).

A.W Hidayat. (2013). Analisa Setting Rele Arus Lebih dan

Rele Gangguan Tanah pada Penyulang Topan Gardu

Induk Teluk Betung. Jurnal Rekayasa Dan Teknologi

Elektro, 7(5), 5–28.

E. Pafela, & E. Hamdani. (2016). Studi Penyetelan Relay

Arus Lebih (OCR) Pada Gardu Induk Teluk Lembu

Defence Scheme on Madura Island Against System Loading Variation for Energy Security

213

Pekanbaru. J. Online Mhs. Fak. Tek. Univ. Riau, 4(1),

1–17.

I. Hajar, & M. Ridho. (2020). Review dan Resetting Skema

Overload Shadding Interbus Transformer Energi dan

Kelistrikan. 12(1).

PT. PLN (Persero). (2010). SPLN T5.002-1:2010 Standar

Pola Proteksi.

SPLN T5.002-1:2010 Standar Pola Proteksi. (2010).

T. Nova. (2013). Perhitungan Setting Rele OCR dan GFR

pada Sistem Interkoneksi Diesel Generator di

Perusahaan. 1(1), 76–85.

U. Induk, P. Pengatur, U. Pengatur, & B. Jawa. (2020).

Defense Scheme Sistem Jawa Timur.

ICATECH 2023 - International Conference on Advanced Engineering and Technology

214