harmonic analysis

KOREA NATIONAL OIL CORPORATION VIETNAM OFFICE

RONG DOI GAS FIELD DEVELOPMENT PROJECT

HARMONIC PENETRATION ANALYSIS

DISCIPLINE ARCH CONST ELECT INSTR MATRL MECH PIPING PIPELINE PROCESS SAFETY STRUC

SIGN/DATE - - - - - - - - - - -

D1 28-APR-05 APPROVED FOR CONSTRUCTION YSN JUB/MSH BSK

C1 28-APR-05 APPROVED FOR DESIGN YSN JUB/MSH BSK

B1 28-JAN-05 ISSUED FOR APPROVAL HFS BK KCG TM

A1 26-JAN-05 ISSUED FOR DIC / IDR HFS BK - - -

Rev. Date Description By Checked Approved QA Client

This document is the property of KECS any unauthorized use of the same will be prosecuted.

Total or partial reproduction and/or utilization of this document are forbidden without prior written authorization of the Owner

Category Code Description

Facility 200 Common

Korea National Oil Corporation Vietnam Office

Phase 30 Detailed Engineering

Discipline E Electrical Engineering Type CA Calculation

Project Number

Facility Phase Discipline Type Sequence Number

Revision Code

VN01 200 30 E CA 8007 D1

As per MOM KNOC UL-0004 DEV/S dated 27th April 05, it is concluded that detailed

harmonic analysis calculation is not necessary for Electrical Power System of Rong Doi Gas

Field Development Project. Accordingly this document is issued without change and shall be

treated as final.

Kvaerner E&C Singapore Pte Ltd VN01-200-30-E-CA-8007 i Rev. D1

RONG DOI GAS FIELD DEVELOPMENT PROJECT

HARMONIC PENETRATION ANALYSIS

TABLE OF CONTENTS

SECTION DESCRIPTION PAGE

1.0 INTRODUCTION 1

2.0 OBJECTIVE 2

3.0 ACCEPTABLE HARMONIC DISTORTION LIMITS 2

4.0 STUDIES 3

4.1 CURRENT TOTAL HARMONIC DISTORTION (THDI) 3

4.2 VOLTAGE TOTAL HARMONIC DISTORTION (THDU) 3

5.0 SYSTEM PARAMETERS 4

6.0 HARMONIC PARAMETERS 4

6.1 VSD FOR STARTING MOTOR 5

6.2 UPS AND DC CHARGERS 6

6.3 THYRISTER HEATER 6

6.4 LIGHTING 7

7.0 SYSTEM CONSIDERATION 9

7.1 OPERATING CONDITIONS 9

7.2 ASSUMPTION 9

8.0 METHODOLOGY 10

9.0 CALCULATION 10

10.0 RESULTS 10

11.0 RESULT ANALYSIS 11

SECTION DESCRIPTION PAGE

Kvaerner E&C Singapore Pte Ltd VN01-200-30-E-CA-8007 ii Rev. D1

12.0 RECOMMENDATION 12

13.0 REFERENCES 12

APPENDICES

APPENDIX A HARMONIC ANALYSIS REPORT CASE - I

APPENDIX B HARMONIC ANALYSIS REPORT CASE - II

Kvaerner E&C Singapore Pte Ltd VN01-200-30-E-CA-8007 1 of 12 Rev. D1

1.0 INTRODUCTION

The Kvaerner Engineering and Construction Singapore Pte Ltd (KECS) has

been engaged by a HHI who have been awarded EPIC contract for the project to

undertake certain design and engineering activities for a Rong Doi Gas

Development Project operated by KNOC.

The Rong Doi and Rong Doi Tay Fields are located in Block 11-2 in the Nam Con

Son Basin offshore Vietnam.

The Rong Doi and Rong Doi Tay Fields (RD and RDT) are located approximately

320km to the south-east of Vung Tau and were discovered in 1995 and 1996

respectively by KNOC, working as the Operator on behalf of a consortium of seven

Korean companies. The Rong Doi Tay Field is located approximately 2.5km to the

west of Rong Doi.

The current development schedule will achieve a First Gas Date of 30 September

2006. The field and facilities are designed to deliver an average of 130MMscfd of

sales gas but will have the capacity to produce up to 175MMscfd of sales gas for

short periods.

The objective of the Rong Doi and Rong Doi Tay development is to design, install,

produce and deliver pipeline specification gas to the gas purchaser PetroVietnam, as

per the terms of the Gas Sales and Purchase Agreement (GSPA).

The facilities shall consist of a Wellhead Platform bridge connected (80m) to a

Production Utilities Quarters Compression Platform (PUQC). An FSO will be

installed to receive stabilized condensate stripped from the gas via a 2.5 Km long 6"

line. The gas will be transported by a 58 Km 18 pipeline to a Wye in Namcon Son

gas trunk line operated by BP.

Drilling activities will be performed by a jack-up rig with all weather capability.


2.0 OBJECTIVE

Harmonic analysis has been carried out to study the performance of the electrical

system with harmonic loads. The purpose of harmonic analysis is to arrive at the

total harmonic distortion at various locations due to harmonic producing loads in

the network and to determine the corrective measures required to reduce the

harmonic distortion to acceptable levels. Normally harmonic analysis is conducted

when harmonic producing loads exceed 10% of total load. In Rong Doi Gas Field

Development Project, the harmonic producing loads such as UPS, rectifiers,

variable speed drives, thyrister control heaters and lighting constitutes more than

10% of total running loads. This has necessitated to conduct detail harmonic

analysis for the complete Generation and Distribution System for Rong Doi Project.

This study considered the impact of the harmonic producing equipment installed on

Wellhead Platform (WHd) and Production Utilities Quarters Compression Platform

(PUQC).

3.0 ACCEPTABLE HARMONIC DISTORTION LIMITS

The total harmonic voltage distortion shall be limited to following values as

indicated in Table 3.1 in compliance to IEC 61000.

TABLE 3.1

LOAD DESCRIPTION TOTAL HARMONIC DISTORTION

(VOLTAGE) THDU

Sensitive Loads (UPS, Computer, PCS, Printers, Monitors)

5%

Industrial Loads (Motors, Heaters, Capacitor Lighting,

Actuators) 8%

Note : As per agreed design basis, the THD (V) shall be limited to 5% in Rong Doi

Electrical Power Distribution System.

The total harmonic current distortion limits THD (I) is not well defined in IEC for

power distribution system. The total current distortion limits are considered as per

IEEE 519-1992. The individual harmonic current and total harmonic current

distortion limits are defined in IEEE Std 519 Table 10.3 and the same is reproduced

below for information. The current distortion limits for distribution system are


indicated in Table 3.2 below.

TABLE 3.2 - CURRENT DISTORTION LIMITS FOR GENERAL DISTRIBUTION SYSTEM (120V THROUGH 69,000V

MAXIMUM HARMONIC CURRENT DISTORTION IN PERCENTAGE OF IL

Individual Harmonic Order (Odd Harmonics)

Isc/IL


VHL : Rms value of fundamental voltage.

5.0 SYSTEM PARAMETERS

The electrical network for Rong Doi Gas Field Development Project has been

planned as per Electrical Overall Key Single Line Diagram drawing number VN01-

200-30-E-DW-1100. Harmonic Penetration Analysis has been carried out for the

entire system network in WHd and PUQC considering all harmonic sources. The

basic network parameters for the Electrical Distribution System are as follows:

TABLE 5.1 - GENERATOR PARAMETERS

DESCRIPTION RATING %

IMPEDANCE

MAX. POWER OUTPUT AT

SITE CONDITION

REMARKS

Generator 230-GT-8001A 1500 kVA /

400 V 12.0 % 1000 kW -

Generator 230-GT-8001B 1500 kVA /

400 V 12.0 % 1000 kW -

Generator 230-GT-8001C 1500 kVA /

400 V 12.0 % 1000 kW -

Emergency Generator 230-GD-8002 750 kVA /

400 V 9.0 % 600 kW -

TABLE 5.2 - NER PARAMETERS

DESCRIPTION IMPEDANCE REMARKS

230-NER-8001A 4.6 -

230-NER-8001B 4.6 -

230-NER-8001C 4.6 -

230-NER-8002 4.6 -

6.0 HARMONIC PARAMETERS

The electrical network at Rong Doi Gas Field Development Project WHd and

PUQC Platform feeds various types of loads. The major harmonic producing loads

are as follows:

Variable speed drives for Generator & Compressor starting motor

AC UPS

Battery chargers (GT & Nav Aids)


Thyrister heater

6.1 VSD FOR STARTING MOTOR

There are three (3) VSD drives for gas turbine generator starting motor and one (1)

VSD drive for flash gas compressor starting motor. However, each VSD is

assumed to produce the harmonic current content as per IEEE 519 and same is

detailed in Table 5.2. This assumption is made in view of VSD shall be procured to

meet IEEE 519 requirement.

Under normal operation, one (1) VSD drive for flash gas compressor is considered

as continuous harmonic source contributing to the electrical network. While during

emergency operation, one (1) VSD drive for gas turbine generator shall be deem as

harmonic source. They are connected to LVS A switchboard and Table 6.1 shows

the VSD rating considered for this study.

TABLE 6.1 VSD LOAD RATING

VSD TAG VSD RATING (kVA)

SWB-8301

A-8001A 98.8

KM-2401 384.3

TABLE 6.2 - HARMONIC CURRENT IN VSD

HARMONIC ORDER COMPONENT CURRENT % OF

FUNDAMENTAL

1 100

5 4

7 4

11 2

13 2

17 1.5

19 1.5

23 0.6

25 0.6

29 0.6

31 0.6

35 0.3



FUNDAMENTAL

37 0.3

Note : The above data used is defined by IEEE Std 519-1992 Table 10.3. This value shall

be applied for all VSD. However actual vendor data shall be used once it becomes available.

6.2 UPS AND DC CHARGERS

There are two (2) UPS, each rated at 40kVA output, four (4) Gas Turbine DC

Battery Chargers each rated at 12kVA, and one (1) Navigational Aids battery

Charger rated at 3kVA (Refer section 7.1 for operational consideration). In this

harmonic study, the UPS loads are separately modelled while the Battery Charger

loads are lumped at respective switchboard. The harmonic current content at UPS

and DC Chargers is also considered as per IEEE 519 and same is given in Table 6.3

below.

TABLE 6.3 - HARMONIC CURRENT IN UPS & BATTERY CHARGER


FUNDAMENTAL

1 100

5 4

7 4

11 2

13 2

17 1.5

19 1.5

23 0.6

25 0.6

29 0.6

31 0.6

35 0.3

37 0.3

Note : The above data used is defined by IEEE Std 519-1992 Table 10.3. This value shall

be applied for all UPS and Battery Charger. However actual vendor data shall be used once it becomes available.

6.3 THYRISTER HEATER


Heater load that utilised thyrister control will contribute harmonic and thus

considered as harmonic source. There are three (3) heater loads considered for

harmonic study as shown in Table 6.4. The harmonic current content is assumed o

be the same for all heaters as detailed in Table 6.5.

TABLE 6.4 HEATER LOAD RATING

Continuous Load TAG NO. DESCRIPTION

kW kVAR

SWB-8301 Switchboard A

E-4401 Fuel Gas Superheater 69.0 44.6

SWB-8401 Switchboard B

E-4101 HP Flare Drum Heater 31.6 0.0

E-4801 Closed Drains Drum Heater 125.0 142.3

TABLE 6.5 - HARMONIC CURRENT IN THYRISTER HEATER


FUNDAMENTAL

1 100

5 4

7 4

11 2

13 2

17 1.5

19 1.5

23 0.6

25 0.6

29 0.6

31 0.6

35 0.3

37 0.3

Note : The above data used is defined by IEEE Std 519-1992 Table 10.3. However actual

vendor data shall be used once it becomes available.

6.4 LIGHTING


Lighting Loads (Fluorescent fixture, high pressure sodium vapour incandescent

lamp) under normal operating conditions does not produce harmonics. However

during starting specially the chokes do produce harmonics. The impact of

harmonics during starting of chokes operated lighting fixture are ignored due to

short duration

The emergency light fitting with inbuilt battery charger do produce harmonics

continuously. The light fitting with electronic controls also produces harmonics.

The harmonics content of such light fittings shall be limited to IEEE 519.

The impact of harmonic producing lighting loads is evaluated. The harmonic

current content is assumed to be same as per IEEE 519. The emergency lighting

loads is estimated as follows;

TABLE 6.6 - EMERGENCY LIGHTING LOAD

Continuous Load S/No. DESCRIPTION

kW kVAR

1 Platform 15.0 7.26

2 Living Quarter 12.0 5.81

TABLE 6.7 - HARMONIC CURRENT IN LIGHTING LOAD


FUNDAMENTAL

1 100

5 4

7 4

11 2

13 2

17 1.5

19 1.5

23 0.6

25 0.6

29 0.6

31 0.6

35 0.3

37 0.3


Note : The above data used is defined by IEEE Std 519-1992 Table 10.3. However actual vendor data shall be used once it becomes available.

7.0 SYSTEM CONSIDERATION

7.1 OPERATING CONDITIONS

Harmonic analysis has been carried out using EDSA with the above parameters.

Normal electrical power system operation has been considered, while the harmonic

sources in the electrical network have been considered under full production

condition.

The impact of harmonics on the system is highest where the system has maximum

impedance. The harmonic contribution of the VSD drive for starting AC motor has

been considered despite the short duration during starting. To check maximum

impact, however it may not be necessary to consider for sizing filter etc. Only one

(1) such VSD drive shall be connected at any one time depending on the operation.

The complete interconnected network has been simulated for harmonic study.

Both 40kVA AC UPS are normally loaded to 50% capacity but during emergency

generator operation, only one is considered as 100% loaded. Although DC battery

chargers for Gas Turbines shall be operating at full capacity for short duration but to

observe maximum impact they have been considered as continuous load.

For the purpose of harmonic analysis, all the major loads have been considered

including all supporting process loads in the network. The harmonic source is

separately modelled where individual load has been represented in the network. The

lump load model that contain harmonic, its contribution is lumped under the

respective LVS A or LVS B switchboard.

Note : Please note that Electrical Power Generation and Distribution System for Rong Doi Gas

Field Development project has been designed to feed electrical loads of PUQC platform & WHd platform only. The drilling loads, workover loads or any other external loads are not considered in design and shall not be feed from this power system. The drilling and workover loads usually have high harmonic content and may adversely affect the power system.

7.2 ASSUMPTION

a) The amplitude of all the harmonic sources considered is based on IEEE


standards 519 Table 10.3.

b) Cable impedance has been considered as per Kukdong Cable Vendor data

available, and Motor parameters where not available are assumed based on

IEC / IEEE standards, while generator sub transient reactance used are based

on data supplied by KNOC / HHI.

c) Non harmonic loads are simulated as lumped load where not indicated.

Harmonic producing loads are combined together with non harmonic

producing loads under LVS A and LVS B switchboard for harmonic

analysis.

8.0 METHODOLOGY

Harmonic study has been carried out on the EDSA Technical 2004 (Electrical

Design and System Analysis) Software of EDSA Micro Corporation USA.

9.0 CALCULATION

Refer to Appendix A and B for EDSA computer printout report.

10.0 RESULTS

Below is a series of tabulated result for two (2) cases of the Harmonic Analysis

conducted under Normal Operation where all loads for production are connected,

and Emergency Operation where only essential loads in switchboard LVS A are

connected.

Although relative harmonic impact will be higher during start up of emergency

generator as loads on it will comprise of mainly AC UPS and lighting. But it will

persist for small duration i.e. switching transients and step loading till other loads

on Living Quarters are activated. This transitional period should be minimised. The

emergency transitional period is not analysed due to short duration.

The total harmonic voltage distortion THD(V) and total harmonic current distortion

THD(I) are evaluated on each bus / link and same is reported under respective case.


Case I - Normal Operation

TABLE 10.1

LOCATION(BUS) VOLTAGE (VOLTS)

THD(V)

%

THD(I) %

PUQC Platform

SWB-8301 400 1.02 1.59

SWB-8401 400 1.02 1.17

MCC-8302 400 1.00 5.22

DP-8203 400 0.31 6.79

DP-8204 400 0.31 6.79

WHD Platform

MCC-8402 400 1.02 0.49

Case II - Emergency Operation

TABLE 10.2

LOCATION(BUS) VOLTAGE (VOLTS)

THD(V)

%

THD(I) %

PUQC Platform

SWB-8301 400 0.84 2.68

SWB-8401 - - -

MCC-8302 400 0.82 8.15

DP-8203 400 0.62 6.79

DP-8204 - - -

WHD Platform

MCC-8402 - - -

11.0 RESULT ANALYSIS

The harmonic analysis indicates that voltage distortion on all the switchboards,

MCC and distribution buses are within normal industry acceptable level of 5%. The

maximum total voltage distortion THD(V) for the two (2) cases is only 1.02% on

SWB-8301, SWB-8401 & MCC-8402 switchboard. This is not considered to be

significant to the system network and is acceptable for industrial loads. The


maximum total current distortion THD(I) 8.15% is observed at switchboard MCC-

8302 for living quarter loads. This information shall be used when sizing circuit

breakers along this path. Further UPS vendor to limit output harmonic current

distortion less than 5%, in view of the 6.79% THD(I) at the AC UPS distribution

panel.

12.0 RECOMMENDATION

The Electrical distribution network at Rong Doi Gas Field Development Project has

been analysed in detail to check the suitability under normal and emergency

operating conditions with harmonic producing loads. Since the harmonic distortion

is within acceptable limits, there is no need to apply separate harmonic filter in

Rong Doi distribution system.

13.0 REFERENCES

VN01-200-25-E-PH-0001 Electrical Systems Philosophy

VN01-200-30-E-DW-1100 Electrical Overall Key Single Line Diagram

VN01-200-30-E-CA-8001 Load Flow Analysis

VN01-200-30-E-ST-8002 Electrical Load List - Normal, Emergency & UPS

VN01-200-30-E-CA-8003 Short Circuit Analysis

VN01-200-30-E-CA-8004 Voltage Drop And Cable Sizing Calculations

VN01-200-30-E-CA-8005 Motor Start-up Analysis On Large Load

VN01-200-30-E-CA-8009 Main & Emergency Generator Capacity Study &

Calculations

Kvaerner E&C Singapore Pte Ltd VN01-200-30-E-CA-8007 Rev. D1

APPENDIX A

HARMONIC ANALYSIS REPORT

CASE - I

(9 SHEETS)

Kvaerner E&C Singapore Pte Ltd VN01-200-30-E-CA-8007 Rev. D1

APPENDIX B

HARMONIC ANALYSIS REPORT

CASE - II

(7 SHEETS)

harmonic analysis

Documents