An Application for Upgrading the Reliability of Electrical System in an Industrial Plant

8/3/2019 An Application for Upgrading the Reliability of Electrical System in an Industrial Plant

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The Online Journal on Electronics and Electrical Engineering (OJEEE) Vol. (3) No. (3)

Reference Number: W11-0068 443

An Application For Upgrading The Reliability

of Electrical System in An Industrial Plant

H. Can

Tupras Izmit Refinery, Project Department, Kocaeli, Turkey

Dr. C. Perdahci

Department of Electrical Engineering, Kocaeli University, Kocaeli, Turkey

Abstract-In this paper, respectively, the requirement for

digital protection relays, current status of the industrial

plants, protective functions of digital protection relays,

relay types, electrical equipments and remote monitoring

relays were examined in an industrial plants. A large-scale

industrial plants must be robust to operate efficiently and

without interruption of power network. Unreliable

electrical network can cause unexpected power

interruptions. Interruptions will damage to operate the

plants and these may also cause significant financial loses.

To make reliable electrical system of the plants, provides

important advantages in terms of operation and

maintenance. In industrial plants examined for this

purpose to establish the digital protection relays and

power relays with the method of monitoring via SCADA

system to increase the reliability of an application is

examined.

Keywords-Protection relays, reliability

I. INTRODUCTION

Today one of the most important factors which ensure that

industrial plants have sustainable production is uninterrupted

and high-quality provision of power to the plant. Ill-timed

power failures due to the own structure of the facility and

national network of which it is a part have significant impact

on the production of facility. The power failures also have

significant financial losses. Therefore the less power failures,

the less financial losses there will be.

Another reason of the significant of power failures is that

the interruption experienced during operation can damage

equipment and due to this damage they can be completely

non-operable and in need of repair. If there is no replacementfor the equipment at the facility, the damage can be

multiplied.

Parallel to the experienced technological developments,

large industrial facilities renew their infrastructures so as to

improve the reliability of their electrical systems (1). One of

the best-known methods is to install digital protective relays

on engines, transformers and entry-exit coupling cells and

corrections of failures at minimum location at minimum time.

At large industrial facilities which have protective functions

assigned to digital protective relays, as well as different

voltage levels and a widespread distribution infrastructure,

high-level of protection can be provided with properselectivity efforts; however, failure and measurement data of

these equipment are transferred to SCADA system at main

focus and they can be used in an effective manner; it also

helps optimize the reliability of the facility. In addition, with

the failure record data obtained from relays, the failure

characteristic of the equipment can be generated and potential

failure risks can be estimated for the future [2].

In the industrial facility, which is the reference of thisstudy, protective equipment have been used since its

foundation which have the highest technology. However, there

are no digital protective relays in several engines,

transformers, entry-exit and coupling cells of the facility. This

application covers replacement of current mechanical relays

with digital protective relays and installation of digital

protective relays to those which had no relays on.

II ELECTRICAL SYSTEM of THE FACILITY

Electricity production capacity of the plant is 85MW and

maximum consumption is 57MW; it also has an auto-producer

license. The facility can satisfy all or part of its own electrical

power need from its production; it can also provide theelectrical power needed from outside as it is connected to the

interconnected network. The purpose of the facility in

producing its own electricity is to create alternatives for

meetings its electricity need rather than selling it to third

parties. As can be understood from the single line graphic of

the facility, all busbars have two supplies. The power is being

distributed to three secondary distribution stations at 11kV

and 3.3kV voltage levels from closed switch station. These 6

secondary distribution stations distribute to 14 secondary

stations. The voltage levels of secondary distribution stations

are 11kV or 3.3kV. There are digital protective relays at

engine, transformer, entry-exit or coupling cells; however

these relays have been established at different times and with

different models since the foundation of the facility [3].

1. Current busbars and protective relays

34,5kV, 11kV and 3,3kV distribution stations which

constitute the distribution infrastructure of the facility are

given in Table 1.


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Distribution

Stations

Voltage

Level

Supplying

Busbar1 9HS-1 34,5kV TEK-2

2 9MMS-1 11kV 9HS-1

3 9MMS-2 11kV 9HS-1

4 9MMS-3 11kV 9HS-1

5 10R-102A 3,3kV 9HS-1

6 10R-6A 3,3kV 9HS-1

7 10R-18A 3,3kV 9HS-1

8 PLANT-5-6-7-8 3,3kV 9MMS-1

9 PLANT-21-25-36 3,3kV 9MMS-1

10 9MS-1 3,3kV 9MMS-1

11 PLANT-6 3,3kV 9MS-1

12 PLANT-73-74 3,3kV 10R-102A

13 10R-102 3,3kV 10R-102A

14 PLANT-33 3,3kV 10R-102A

15 10R-6 3,3kV 10R-6A

16 10R-8 3,3kV 10R-18A

17 47MMS-1 11kV 9MMS-2

18 47MS-1 3,3kV 47MMS-1

19 10MS-1 3,3kV 9MMS-320 63MMS-1 11kV 9MMS-3

21 63MS-1 3,3kV 63MMS-1

Table 1 : Distribution Stations

2. System equipment with digital protective relays

installed

Digital protective relays will be used for the purpose of

protecting several equipment in the facility and improving the

reliability of electrical system. These relays will be installed

on engine feeders, transformer feeders, entry-exit and

coupling cells [3].

Digital protective relays will be installed on 10R-6 and10R-6A power switch building, 10R-102A power switch

building, Plant 25-36 , Plant 5-6-7-8 , Plant 47-48 , Plant 26,

Plant-33, Plt 9 and 34,5kV switch facility engine feeders,

transformer feeders, entry-exit and coupling cells shown in

Table 1 [2].

Digital protective relays have been applied on more than

200 medium-voltage system equipment; those installed on 47-

48 unit are given in Table 2 [3]. 47-48 (Hydrocracker) unit

constitutes one of the most important processes of the facility.

PLANT 47/48 UNIT SWITCH ROOM

CellNo Name Of TheEqupment Description of Equipment

11 kV BUSBAR 47 MMS-1

5L 9GM-601A 11kV 1200kW Pump Motor

4L 47GM-2A 11kV 1550kW Pump Motor

3L 47KM-2A

11kV 3500kW Compressor

Motor

2L

47TMM-1A

Trafosu Fideri 11kV to 3,5kV 6,3MVA

1L Incoming L INCOMING LEFT

0 BUS TIE

0 BUS RISER

1R Incoming R INCOMING RIGHT

2R

47TMM-1B

Transformer

Feeder 11kV to 3,5kV 6,3MVA

3R 47KM-2B


Motor

4R 47KM-2C


Motor

5R 47GM-2B 11kV 1550kW Pump Motor

6R 9GM-601B 11kV 1200kW Pump Motor

3,3 kV BUSBAR

11L 47GM-4C 3,3kV 153kW Pump Motor

9L 9KM-601E3,3kV 120kW CompressorMotor

8L 9KM-601C

3,3kV 120kW Compressor

Motor

7L 9KM-601A


Motor

6L 47GM-302A 3,3kV 120kW Pump Motor

5L 48KM-1A


Motor

4L

47TML-1C

Transformer

Feeder 3,3kV to 0,4kV 2MVA

3L EMPTY

2L

47TML-1A

Transformer


1L Incoming L INCOMING LEFT

0 BUS TIE

0 BUS RISER

1R Incoming R INCOMING RIGHT

2R

47TML-1B

Transformer


3R

47TML-1D

TransformerFeeder 3,3kV to 0,4kV 2MVA


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87M: Engine differential protection*

*Engine differential protection is not compulsory;

nevertheless, differential protection is recommended on

engines higher than IMW power. Differential protections at

powerful engines bigger than IMW at this facility have been

enabled. Protection functions employed on transformers:

49: Motor Thermal protection

50, 50N: Instant opening

51, 51N: Opening at overflow

Inrush restraint (valid for 50,50N, 51, 51N, 67, 67N functions)

74: Alarm

74TC: Trip Circuit Supervision

87T: Transformer Differential Protection*

*at transformers of 5MVA and higher at the facility 49: used in relays at primary sides of thermal protection

transformers; not enabled on relays at secondary side.

The protection functions defined in digital protection relays

installed on transformer feeders have been enabled and

adjustment values have been given. 67, 67N: Directional

Overflow Protections have been enabled as these generators

exist at 11kV outlets of 34,5/ 11kV transformers in the

facility; which means at facility entrances, and as it is not

possible to feed from TEA and generators alike. In addition,

32G, 32P: Inverse Power Protections are also enabled.

Protection Functions used in the Generators: 27 : Low Voltage Protection

32R: Diverse Power Protection

46 : Current Protection for Negative Component Phase Balance

49 : Thermal Protection

50, 50N : Instant turn-on protection (Short circuit protection)

51, 51N(51G) : Over-current protection (reverse time protection)

59 : Over-Voltage Protection

81 : Low / Excessive Frequency protection

87G : Generator Differantial Protection (G Generator)

3.1 Measurement with Digital Protection Relays

As the digital protection relays to be used also have

measurement functions, the demanded cells will also be

measured. In addition to protection, which is their mainfunction, digital protective relays are able to measure the

current, voltage and frequency values of the cells on which

they are installed this cell can be an engine feeder,

transformer feeder or entry-exit and coupling feeder. In

addition, they can transmit these measured values to SCADA

system, just like they transmit protection functions to SCADA

system. As a result, in addition to their major function which

is protection, these relays used within the Refinery Plant will

transfer such values as the current voltage frequency of the

equipment to which they are installed to the SCADA system

to make the electrical system of the plant more traceable and

reliable, as electrical systems which can be monitored are

always more reliable. Measurements which will be made by

relays are as follows: [2]

Component values with symetry for voltages

Voltages (VL1,VL2,VL3,VL1L2,VLL1L3,VL2L3)

Current power, Reactive power, Visible power (Eachphase seperately and totally)

Aktive and Reactive Energy

Power Factor and Frequency

Working hour gauge, breaker opener gauge

Measuring of average operating temperature in case of

overload

IV. DIGITAL PROTECTION RELAYS USED

A. Local-control multi-functional protective relay 7SJ64

Digital, multi-functional SIPROTEC 4 7SJ64 relays are

multi-faceted devices designed for protection, control and

monitoring of busbar relays. These devices can be used as lineprotection in grounded, low-resistant grounded, non-rounded

or compensated neutral point-structured networks. Devices

are proper for radial, eyed or interconnected networks and

single or multi-edged fed lines. 7SJ64 has been equipped with

engine protection function which can be adjusted for every

size of non-synchronize engines. 7SJ64 has necessary

functions for command of breakers at1 breaker busbars or

monitoring of protective, breaker positions and flat busbar

applications. Therefore the device can be used universally.

7SJ64 provides after-effect protective features for differential

protective arrangements of the lines, transformers, generators,

engines and busbars in all voltage levels.

Protection of non-directional overflow is the basic function

of the device. There are three fixed-time overflow protective

elements and one inverse time overflow protective component

for phase currents and ground current. Several curves at

different standards are provided for inverse-time overflow

protective elements.[5]

B. Differential protective relay 7UT613

SIPROTEC 4 7UT613 digital differential protection

provides a fast and selective short circuit protection for

transformers at all voltage levels, rotary machines, serial and

shunt reactors or short lines and mini busbars consisting of 2

to 5 feeders. In addition, it can also be used as a single-phaseprotection for busbars up to 9 or 12 feeders (depending on the

version). Specific application can be customized which will

ensure the most appropriate adaptation to the protected object.

The major advantage of differential protection principle is

that it can perform instant turn-on at a short circuit failure at

any point within the protected area. The current transformers

at the edges of protected object limits the protected area

towards the network. This certain limit is the main reason for

which the differential protection mechanism shows such an

ideal selectivity. [6].

1. Remote Monitoring of Digital Protective Relays

All established protective relays will be monitored fromPower CC SCADA system which is installed in Plant-9. All

trips, alarms, external data and analogue value signals will be


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sent to Power CC scada system from these relays. Only the

Power CC in Plant-9 will be controlled by SCADA system

and switch will be opened and closed from there [2].

V. CONCLUSION

As a result of this paper which aimed at improving the

reliability of current electrical system, the system has been

made more reliable with the protection functions from which

digital protective relays are entered. Protective functions have

been parametered as required according to the type and

importance of the equipment to which the relays are

connected, and it has been ensured that the system makes less

trips. In addition, remote monitoring of the system has

allowed for receiving instant information from relays which

turn on or give alarm and thus faster intervention.

In this study, not only the electrical system of the plant hasbeen made more reliable, but the plant also enjoyed several

advantages such as costing, operation and maintenance.

REFERENCES

[1] Xiaoqiang, Z., "Energy&Utilities Control System ofRefinery",2009 third International Symposium on

Intelligent Information Technology Application, 2009,

408-411

[2] etinkaya, B, Akduman, B, Tpra Izmit Role

Koordinasyon Raporu, Siemens A.S., Kocaeli, 2009

[3] TUPRA General Project Design Specification P1,

TUPRA, Kocaeli, 2006

[4] Koruma Rolelerinin Fonksiyon Acklamalar, Siemens E

E&C PTI, Istanbul, 2008

[5] SIPROTEC 7SJ62/64 Kullanm Klavuzu C53000-

G115A-C207-1, SIEMENS AG, Istanbul, 2009

[6] SIPROTEC 7UT613/63x Kullanm Klavuzu V4.60,

SIEMENS AG, Istanbul, 2006

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An Application for Upgrading the Reliability of Electrical System in an Industrial Plant