7.1 Scoop of Works
-7.11 Project Planning
Economics and feasibility studies, preminary engineering design, cost estimates and economic evaluation of any alternatives. The projects are done without waste the money .The consultant also give advices on site selection, construction method and equipments
-7.12 Project Management
Planning, coordination and control of all activities of any project in terms of cost estimation time and function to ensure that the clients the objectives are met.
-7.13 Advisory Activities
Design reviews and independent design checks certification procedures and expert advise in all areas of the firm expertise.
-7.14 Engineering Design
Conceptual design, detailed design, drawing and specification, cost estimates and project scheduling.
-7.15 Tender Arrangement
Preparation of tender documents, registrations of tenders, invitation to tender and orders to nominate sub-conductor. Tender evaluation, interview and recommendations.Prepations of contracts documents.
-7.16 Contract Administration
Financial control, payment certificated and settlement of accounts.
-7.17Supervision of Construction
Quality control and inspection of fabrication and construction. Provision resident engineer, supervisor and inspectors.
7.2 TESTING AND COMMISSIONING
7.21 Primary Injection Test
The purpose of PI test is:
a) to ensure that the system wiring connection is in order
b) to check CT’s ratio and polarities
c) to confirm that the CT’s characteristic are matched with each others
7.211 Test Procedures
The testing procedures are as follows:
a) Set up the PI set and connect the ammeters as shown in the diagram below for various protection scheme
b) Ensure continuity of the secondary circuit by switching the ammeters to ohm range
c) Ensure that the primary circuit is in order and inject primary current equal to half of the rated primary current of the CTs.Take ammeters readings
d) Bring up the current to the rated primary currents of the CT’s and take reading again
e) For new equipment is in order, the leakage current should be lower than the max acceptable value
7.22 Secondary Injection Test
The prime purpose of secondary Injection Test (S.I) test is to ensure the entire relay is functioning as excepted. It is very important to test the protective relays for the correct operation of the circuit breaker under normal and fault conditions. This is the responsibility of there testing officer to make appropriate interpretation on test results and initiate the necessary action for remedy action for remedy if required.
Precaution: Do not open-circuit the secondary of a CT while there is a produced in its secondary which may be dangerous to persons and may also damage the insulation of the secondary wiring.
7.23 Test for Over-Current or Earth-Fault Relay
The purpose of the test is to measure that the relays are in a good condition and can play a role as a back up protection unit.
Procedure:
1) We need to short circuit of the CT ,and take up the CT wiring on the relay
2) Set up and injection device and inject the current to the relay check the crippling ampere
3) Continue inject current according to the data shhet.1.3x,2x,3x and record down all data time of tripping and current injection and relevant information
4) Inject at the 2 or 3x rated current and set on the shunt trip coil of the Circuit Breaker
*The circuit diagram of o/c & e/f attached appendix
*Attached with a sheet of the over-current and earth fault relay at appendix
7.24 High Tension Test
7.241 A.C Pressure Test
Before the power equipments are put in services ,they are subjected to high tension test to ensure that the insulation level of the equipment is high enough to withstand over-voltage under different conditions,eg switching transient ,system fault ,lighting surge ,etc the A.C pressure test is applicable for switchgear ,bus-bar ,current transformer ,potential transformer and power transformer.
7.242 D.C Pressure Test
D.C pressure test is applicable to power cable only .We do not apply A.C pressure test for cable because the capacitance of the cable is very high.
7.25 Contact Resistance Test
To ensure the resistance of the circuit breaker main contact still within the range according to international standard
7.26 Transformer Dielectric Oil Test
The purpose of Dielectric Oil Test is to ensure that:
1) Determining the dielectric strength of insulating oils in transformer ,switchgear ,and other electrical apparatus
2) Oil degradation takes place due to oxidation ,acids ,sludge ,gas , and water absorption
7.27 Cable Continuity
The purpose of the test:
1) To make sure the control cable laid by the contractor is according to the specification and design
2) To confirm no damage on the cable and ferruling of multi –cores are as per cable core schedule
7.28 Insulation Test for Cable
The purpose of the test:
1) Make sure the other cable is isolated from earth
2) Make sure no direct fault to earth of the cable cores
7.29 Current Transformer
Current Transformer divides into two types namely: metering and protection
For metering is using Class 0.1 to Class 5.Smaller number of class, the higher the accuracy is
For protection is using 5P10, 10P10, 10P5 and others
Example: 5P10; 5=percentage of error and 10=times of saturation point
Some of the test result attached at appendix
7.7 SINGLE POINT BONDING
-For short cable, eg: Transformer tail and from panel PMU to panel SSU at the same premise/substation
7.8 Difference between Flat and Trefoil Cable
-Higher ampacity(for non-touching flat) -Lower ampacity
--Higher unbalanced voltage (limit of unbalanced<2%) -There is no unbalanced voltage
-Needed transpose core at every joint which is made from crossbond -Need not transpose core. Only crossbond
-More easier and simply,
7.9 Failure of Underground Cable
-Based on research, main reason around 54% shown that failure of underground cable caused by excavation by third party.
-This failure included excavation activities at the side road
-Period of failure:
-Immediately-once excavate will spoil
-Spoil after a period of time-Cable be distressed or flat caused by excavation
-7.91 Increment Degree Of Depth Due To Plantation Of Cable
-Avoid cable from top bucket junkets which is used by third person during excavation. Degree of depth had to increased from 2.5 feet to 3.5 feet
-Below figure1 shown the most accurate and safe location of cable after testing the depth of excavation of cable
Figure1
Latest method of plantation cable with explanation depth
Sunday, June 27, 2010
Tuesday, June 8, 2010
2-3/6/10
Safety Precaution:
Every switching is very important .Safety precaution must take it seriously .Below are the Switching precautions.
1) Before we do any switching, we must write down all the switching procedure clearly and explain to CP(Competent person)/team members.
2) Every switching ,AP(Authorize Person) must accompany by a CP(Competent Person),this is because CP will observe whether AP is doing the right procedure.
3) AP must make sure inside the substation has enough lighting to do switching.
4) AP must make sure in front of switching panel laid a rubber map on floor for safety purpose.
5) AP must wear PPE(Personal Protective Equipments)fully .Example of PPE :Fire Redundant Suit ,Glove ,Safety helmet with vessel ,Safety boots.
6) AP have to make sure and check all the tools are in good condition and fulfill TNB standard and record down in a check list.
7) AP must record down every load reading before and after inside a log book for reference.
8) Before switching ,AP must check whether switch gear is in good condition to do switching .Standard checking can be done with checking SF6 Gas Gauge at the switch gear ,and observe any blackening marks on physical switch gear or checking whether got Ozone smell from the switch gear or not.
9) Every switching activities must come out with 4 important steps Switch Off ,Rank Out ,Prove Dead ,Earth On
10) Phasing stick is used to prove the system dead .There are two type of phasing strict ,namely subtraction and addition types .A subtraction phasing stick in phase it will show 0V,meanwhile Addition Phasing Stick type in phase will show 12.6V.
11) “Non Standard ”lock is a need to lock at the switch gear handle termination/PDS(Partial Discharge Spout) to prevent anonymous people go and do a dangerous switching.
12) Precaution notice needed to put on the non standard lock and written person in charge Name and Hand Phone Number.
13) Barriers and dangerous notice needed to put in front of work space to aware public on safety.
14) PTW(Permits to works)only can be issued to contractor when the system is proven dead and Earth On.
Every switching is very important .Safety precaution must take it seriously .Below are the Switching precautions.
1) Before we do any switching, we must write down all the switching procedure clearly and explain to CP(Competent person)/team members.
2) Every switching ,AP(Authorize Person) must accompany by a CP(Competent Person),this is because CP will observe whether AP is doing the right procedure.
3) AP must make sure inside the substation has enough lighting to do switching.
4) AP must make sure in front of switching panel laid a rubber map on floor for safety purpose.
5) AP must wear PPE(Personal Protective Equipments)fully .Example of PPE :Fire Redundant Suit ,Glove ,Safety helmet with vessel ,Safety boots.
6) AP have to make sure and check all the tools are in good condition and fulfill TNB standard and record down in a check list.
7) AP must record down every load reading before and after inside a log book for reference.
8) Before switching ,AP must check whether switch gear is in good condition to do switching .Standard checking can be done with checking SF6 Gas Gauge at the switch gear ,and observe any blackening marks on physical switch gear or checking whether got Ozone smell from the switch gear or not.
9) Every switching activities must come out with 4 important steps Switch Off ,Rank Out ,Prove Dead ,Earth On
10) Phasing stick is used to prove the system dead .There are two type of phasing strict ,namely subtraction and addition types .A subtraction phasing stick in phase it will show 0V,meanwhile Addition Phasing Stick type in phase will show 12.6V.
11) “Non Standard ”lock is a need to lock at the switch gear handle termination/PDS(Partial Discharge Spout) to prevent anonymous people go and do a dangerous switching.
12) Precaution notice needed to put on the non standard lock and written person in charge Name and Hand Phone Number.
13) Barriers and dangerous notice needed to put in front of work space to aware public on safety.
14) PTW(Permits to works)only can be issued to contractor when the system is proven dead and Earth On.
31/5 & 1/6/2010
SIK(perpasangan dan penyenggaraan kabel bertebat seikat diudarakan voltage tinggi)
-Maximum distance span for cabel system HV ABC is 40 meter.
-For every LV ABC system which is using pole of 10 meter has to follow this measurement
-Telecomunication line have to follow below procedur if using HV ABC system:
-minimum distance from HV ABC system =1910mm
-minimum distance from LV ABC system=910mm
-"Kabel kenduran kabel telecomunication"has to follow "kenduran sistem kabel HV
ABC and LV ABC
-Approval aksesori system telecomunication which is implemented at HV ABC pole is:
-Talian telecomunication
-Bracket talian telecomunication
-Sambungan terus /tamatan talian telecomunication
-Any kind of telecomunication devices such as anttena/aerial/peti penyuisan are not allowed implemented at pole.
Site visit to Padang Serai,Kuala ketil on the next day
-defecting of stay
-The function of stay is to balance the forces produced by wind blow.
-Fixing materials and the force from the cable itself
-This tension is formed due to the tension caused by wind blow to the cable system on ABC
-The installation method of stay is similiar to the method used for 33kv of non insulated cable system
-The stay installer should neverbe in contact with wires
-Insullator has to be used on every stay to isolate stay wires form messenger wires and earthed pillars
-stay has to be placed on 45 degree angles as possible.
-
-Maximum distance span for cabel system HV ABC is 40 meter.
-For every LV ABC system which is using pole of 10 meter has to follow this measurement
-Telecomunication line have to follow below procedur if using HV ABC system:
-minimum distance from HV ABC system =1910mm
-minimum distance from LV ABC system=910mm
-"Kabel kenduran kabel telecomunication"has to follow "kenduran sistem kabel HV
ABC and LV ABC
-Approval aksesori system telecomunication which is implemented at HV ABC pole is:
-Talian telecomunication
-Bracket talian telecomunication
-Sambungan terus /tamatan talian telecomunication
-Any kind of telecomunication devices such as anttena/aerial/peti penyuisan are not allowed implemented at pole.
Site visit to Padang Serai,Kuala ketil on the next day
-defecting of stay
-The function of stay is to balance the forces produced by wind blow.
-Fixing materials and the force from the cable itself
-This tension is formed due to the tension caused by wind blow to the cable system on ABC
-The installation method of stay is similiar to the method used for 33kv of non insulated cable system
-The stay installer should neverbe in contact with wires
-Insullator has to be used on every stay to isolate stay wires form messenger wires and earthed pillars
-stay has to be placed on 45 degree angles as possible.
-
23-27/5/10
PPU Naka,Kuala Nerang
-There are two type of transformer:power transfomer and distribution transformer
-There are also two type of tap changer:off circuit tap changer and on load tap changer
-Step up transformer increases the voltage while decreasing the current,while a step down transformer decreases the voltage while increasing the current for domestic and commercial distribution.
-Silical gel is a granular,vitreous ,highly porous form of silica made synthetically from sodium silicate.
-silica gel is most commonly encounted in everyday life as beads packed in a vapor-permeable plastics;used as a desciccant to control local humidity in order to avoid spoilage or degradation of some goods.
-Silica gel have very high absorption of moisture(because of poisonous dopants).
-Insulator:-materials-used to reduced the rate of heat transfer or used to reduce heat transfer.Heat energy can be transferred by conduction ,convention,radiation or by actual movement.
:-Flow of heats can be reduced by addressing one or more of these mechanisms and dependent on the physical properties of the material emplyed to do this.
-PILC(Paper insulated lead sheathed)
:Aluminium and copper conductors
:Single core cables:up to 1kv in size up to 1000sqmm
:Three core cables:up to 1 kv in sizes up to 400sqmm
:speacial cables for mining and submarine applications
-XLPE cable(cross-linked polyethe)
:actually is two semiconductors layers on high voltage cable
:one is between actual conductors and XLPE
:other is on outside of XLPE insulation underneath the concentric neutral
-Semi-con used to equalize the electrical stresses over a large area
-Mineral oil:breakdown voltage more than 30kv and moisture level 33ppm(parks/million)
-Type of joint:normal joint,crossbond joint ,termination and linebox
-There are two type of transformer:power transfomer and distribution transformer
-There are also two type of tap changer:off circuit tap changer and on load tap changer
-Step up transformer increases the voltage while decreasing the current,while a step down transformer decreases the voltage while increasing the current for domestic and commercial distribution.
-Silical gel is a granular,vitreous ,highly porous form of silica made synthetically from sodium silicate.
-silica gel is most commonly encounted in everyday life as beads packed in a vapor-permeable plastics;used as a desciccant to control local humidity in order to avoid spoilage or degradation of some goods.
-Silica gel have very high absorption of moisture(because of poisonous dopants).
-Insulator:-materials-used to reduced the rate of heat transfer or used to reduce heat transfer.Heat energy can be transferred by conduction ,convention,radiation or by actual movement.
:-Flow of heats can be reduced by addressing one or more of these mechanisms and dependent on the physical properties of the material emplyed to do this.
-PILC(Paper insulated lead sheathed)
:Aluminium and copper conductors
:Single core cables:up to 1kv in size up to 1000sqmm
:Three core cables:up to 1 kv in sizes up to 400sqmm
:speacial cables for mining and submarine applications
-XLPE cable(cross-linked polyethe)
:actually is two semiconductors layers on high voltage cable
:one is between actual conductors and XLPE
:other is on outside of XLPE insulation underneath the concentric neutral
-Semi-con used to equalize the electrical stresses over a large area
-Mineral oil:breakdown voltage more than 30kv and moisture level 33ppm(parks/million)
-Type of joint:normal joint,crossbond joint ,termination and linebox
20/5/10
Site visit to Bedong,Sungai Petani.
-New bridge was built but still under construction
-Need to remove old cable to a new joint
-There are two type of joint:crossbond and straight through
-Straight through is referring to the sketching oage
-Crossbond joint installation is almost same as straight through joint
-New bridge was built but still under construction
-Need to remove old cable to a new joint
-There are two type of joint:crossbond and straight through
-Straight through is referring to the sketching oage
-Crossbond joint installation is almost same as straight through joint
16,17/5/2010
PD Mapping:
PD (partial discharges) are small electrical sparks or discharges that occurs in defects in the insulator.
The discharges do not bridge the insulation between conductors and the defects may be:
-entirely within the insulation
-along interfaces between insulating materials
-or along surfaces
Partial discharges characteristics depend on:
-type
-size
-location of defects
-insulating material
-applied voltage
-cable temperature
The damage caused by PD depends on several factors and can be range from negligible to causing failure within days to years.
Important parameters of PD-diagnosis:
-Ground noise level:
Inferences of external noise sources like radio stations ,corona from OH lines ,bad grounding conditions .PD signals below ground noise level can be not determined .Ground Noise Level on site normally between 20 to 100 pC.
-Partial Discharge Inception Voltage –PDIV
Voltage level where first measureable PD pulses are to be seen ,determined by stepwise increase of the test voltage .PDIV should be higher than Uo(normal service voltage).That means the cable is under normal service condition PD free .New installed cables should be PD free up to 2 Uo.
Partial Discharge Extinction Voltage-PDEV
PDEV is often below PDIV,PD starts above Uo in case of an overvoltage can be extinguish below nominal voltage .PDEV should be above Uo.
Condition assess using PD techniques:
-Analysis of HV switchgear fault causes
-Consequences of failure
-EA technology experience and credentials
Reason For Partial Discharge Test
-Insulation failure can be devastating
-Switchgear insulation is difficult to test during routine maintenance
-Many failure of HV insultion sre associated with Partial Discharges
Partial Discharges Measurement Techniques
-Internal Discharge Activity
-Transcient Earth Voltage (TEV)Detection
-Higher frequency(~3 to 80 MHZ)
-Surface Discharge Activity
-Ultrasonic Emission~40KHZ
-TEV detection-when high amplitude surface discharge
PD (partial discharges) are small electrical sparks or discharges that occurs in defects in the insulator.
The discharges do not bridge the insulation between conductors and the defects may be:
-entirely within the insulation
-along interfaces between insulating materials
-or along surfaces
Partial discharges characteristics depend on:
-type
-size
-location of defects
-insulating material
-applied voltage
-cable temperature
The damage caused by PD depends on several factors and can be range from negligible to causing failure within days to years.
Important parameters of PD-diagnosis:
-Ground noise level:
Inferences of external noise sources like radio stations ,corona from OH lines ,bad grounding conditions .PD signals below ground noise level can be not determined .Ground Noise Level on site normally between 20 to 100 pC.
-Partial Discharge Inception Voltage –PDIV
Voltage level where first measureable PD pulses are to be seen ,determined by stepwise increase of the test voltage .PDIV should be higher than Uo(normal service voltage).That means the cable is under normal service condition PD free .New installed cables should be PD free up to 2 Uo.
Partial Discharge Extinction Voltage-PDEV
PDEV is often below PDIV,PD starts above Uo in case of an overvoltage can be extinguish below nominal voltage .PDEV should be above Uo.
Condition assess using PD techniques:
-Analysis of HV switchgear fault causes
-Consequences of failure
-EA technology experience and credentials
Reason For Partial Discharge Test
-Insulation failure can be devastating
-Switchgear insulation is difficult to test during routine maintenance
-Many failure of HV insultion sre associated with Partial Discharges
Partial Discharges Measurement Techniques
-Internal Discharge Activity
-Transcient Earth Voltage (TEV)Detection
-Higher frequency(~3 to 80 MHZ)
-Surface Discharge Activity
-Ultrasonic Emission~40KHZ
-TEV detection-when high amplitude surface discharge
16-19/5/2010
PD Mapping:
PD (partial discharges) are small electrical sparks or discharges that occurs in defects in the insulator.
The discharges do not bridge the insulation between conductors and the defects may be:
-entirely within the insulation
-along interfaces between insulating materials
-or along surfaces
Partial discharges characteristics depend on:
-type
-size
-location of defects
-insulating material
-applied voltage
-cable temperature
The damage caused by PD depends on several factors and can be range from negligible to causing failure within days to years.
Important parameters of PD-diagnosis:
-Ground noise level:
Inferences of external noise sources like radio stations ,corona from OH lines ,bad grounding conditions .PD signals below ground noise level can be not determined .Ground Noise Level on site normally between 20 to 100 pC.
-Partial Discharge Inception Voltage –PDIV
Voltage level where first measureable PD pulses are to be seen ,determined by stepwise increase of the test voltage .PDIV should be higher than Uo(normal service voltage).That means the cable is under normal service condition PD free .New installed cables should be PD free up to 2 Uo.
Partial Discharge Extinction Voltage-PDEV
PDEV is often below PDIV,PD starts above Uo in case of an overvoltage can be extinguish below nominal voltage .PDEV should be above Uo.
Condition assess using PD techniques:
-Analysis of HV switchgear fault causes
-Consequences of failure
-EA technology experience and credentials
Reason For Partial Discharge Test
-Insulation failure can be devastating
-Switchgear insulation is difficult to test during routine maintenance
-Many failure of HV insultion sre associated with Partial Discharges
Partial Discharges Measurement Techniques
-Internal Discharge Activity
-Transcient Earth Voltage (TEV)Detection
-Higher frequency(~3 to 80 MHZ)
-Surface Discharge Activity
-Ultrasonic Emission~40KHZ
-TEV detection-when high amplitude surface discharge
PD (partial discharges) are small electrical sparks or discharges that occurs in defects in the insulator.
The discharges do not bridge the insulation between conductors and the defects may be:
-entirely within the insulation
-along interfaces between insulating materials
-or along surfaces
Partial discharges characteristics depend on:
-type
-size
-location of defects
-insulating material
-applied voltage
-cable temperature
The damage caused by PD depends on several factors and can be range from negligible to causing failure within days to years.
Important parameters of PD-diagnosis:
-Ground noise level:
Inferences of external noise sources like radio stations ,corona from OH lines ,bad grounding conditions .PD signals below ground noise level can be not determined .Ground Noise Level on site normally between 20 to 100 pC.
-Partial Discharge Inception Voltage –PDIV
Voltage level where first measureable PD pulses are to be seen ,determined by stepwise increase of the test voltage .PDIV should be higher than Uo(normal service voltage).That means the cable is under normal service condition PD free .New installed cables should be PD free up to 2 Uo.
Partial Discharge Extinction Voltage-PDEV
PDEV is often below PDIV,PD starts above Uo in case of an overvoltage can be extinguish below nominal voltage .PDEV should be above Uo.
Condition assess using PD techniques:
-Analysis of HV switchgear fault causes
-Consequences of failure
-EA technology experience and credentials
Reason For Partial Discharge Test
-Insulation failure can be devastating
-Switchgear insulation is difficult to test during routine maintenance
-Many failure of HV insultion sre associated with Partial Discharges
Partial Discharges Measurement Techniques
-Internal Discharge Activity
-Transcient Earth Voltage (TEV)Detection
-Higher frequency(~3 to 80 MHZ)
-Surface Discharge Activity
-Ultrasonic Emission~40KHZ
-TEV detection-when high amplitude surface discharge
Thursday, May 13, 2010
9,10/5/10
Protection main function:
1-safeguard the entire system to maintain continuity of supply.
2-minimize damage and repair costs
3-ensure safety of personnel
Protection-basic requirements:
1-Selectivity
2-Stability
3-Speed
4-Sensitivity
Protection basic components:
1-Voltage transformer and Current transformer
2-Fuses
3-Relays
4-Circuit breakers
5-DC batteries
1-safeguard the entire system to maintain continuity of supply.
2-minimize damage and repair costs
3-ensure safety of personnel
Protection-basic requirements:
1-Selectivity
2-Stability
3-Speed
4-Sensitivity
Protection basic components:
1-Voltage transformer and Current transformer
2-Fuses
3-Relays
4-Circuit breakers
5-DC batteries
6/5/10
Differential relay required at least a minimum v alue of current flowing through its operating winding for operation.
-They will only operate if the operating current exceeds a certain percentage of the restraint or bias current.
-This ensures the relays current required for operation is always greater than the out of balance current under maximum through fault condition.
The second bias or restraint incorporated into most transfomer differential relays is the bias to prevent relay operation against magnetizing in rush current on energizing the transormer.
-They will only operate if the operating current exceeds a certain percentage of the restraint or bias current.
-This ensures the relays current required for operation is always greater than the out of balance current under maximum through fault condition.
The second bias or restraint incorporated into most transfomer differential relays is the bias to prevent relay operation against magnetizing in rush current on energizing the transormer.
5/5/10
Relay usually installed with current transformer for current measurement.
-The Relay should not operate when the circuit is carrying the maximum load continuosly.
-When the equipment or circuit is allowed to overload in limited time -say by 30%bfor less than half an hour then the relay should be set not operate at the over loaded current in the slightly shorter than the maximum over load time.
-Under fault condition,the relay should operate and disconnect the circuit in the time before exceeding the short circuit rating of the protective equipment.
-Realys are normally classified into the time/current characteristics as:
*Instantaneous
*Definite-time
*Inverse definite Minimum Time(IDMT)
-The Relay should not operate when the circuit is carrying the maximum load continuosly.
-When the equipment or circuit is allowed to overload in limited time -say by 30%bfor less than half an hour then the relay should be set not operate at the over loaded current in the slightly shorter than the maximum over load time.
-Under fault condition,the relay should operate and disconnect the circuit in the time before exceeding the short circuit rating of the protective equipment.
-Realys are normally classified into the time/current characteristics as:
*Instantaneous
*Definite-time
*Inverse definite Minimum Time(IDMT)
4/5/10
-To meet protection objectives and requirements,protection systems are required where protective devices or gears are combined together ready to disconnect faulted equipment.
-Protective scheme on the other hand is a coordinated arrangement of several protective systems for protection of equipement bor power system.
-Current and voltagte transformers are the common devices used in protective system.
-Voltage transformer are used for measurement ,directional protection -conventional or reverse power relays -undervoltage/overvoltage protection.
-Two types of voltage transformer constrution in used:
*Electromagnetic type:primary and secondary winding are magnetically coupled via iron core.
*Capacitor voltage transformer -which is connected to main circuit with series of capacitors.
-Protective scheme on the other hand is a coordinated arrangement of several protective systems for protection of equipement bor power system.
-Current and voltagte transformers are the common devices used in protective system.
-Voltage transformer are used for measurement ,directional protection -conventional or reverse power relays -undervoltage/overvoltage protection.
-Two types of voltage transformer constrution in used:
*Electromagnetic type:primary and secondary winding are magnetically coupled via iron core.
*Capacitor voltage transformer -which is connected to main circuit with series of capacitors.
Monday, May 3, 2010
3/5/2010
Site Visit to Pencawang Protab Agrobase Packaging,Changlun
Vacuum Test Equipment(Green ~Acceptable,Red~defective);Voltage set at 25kv
Electrical Machinery
LV Distribution Board (pengagihan Bekalan)It also used to trace leakage of electricity,therefore tranduce analog to digital then send to SCADA
Remote Terminal Unit PE Telekom Jitra
Our main objective for today~~to trace out flash over.Needed to confirm whether circuit breakers in the good condition
setting up Vacuum Test
Circuit breakers (After flash over)
Maintenance of circuit breakers
Tracing out each line
Tracing the fault
Drawing out Schematic Diagram(to bring back Pencawang as reference)
Remote Terminal Unit PE Telekom Jitra
Our main objective for today~~to trace out flash over.Needed to confirm whether circuit breakers in the good condition
setting up Vacuum Test
Circuit breakers (After flash over)
Maintenance of circuit breakers
Tracing out each line
Tracing the fault
Drawing out Schematic Diagram(to bring back Pencawang as reference)Sunday, May 2, 2010
Thursday, April 29, 2010
Monday, April 26, 2010
21/4/2010
I learned about Protection Requirements which can divided into 2 categorize:
1)Basic requirements
Basic requirements is that the customer’s arrangements for protection at the connection point ,including types of equipment and protection settings ,must be compatible with standard practices on the TNB’S system and be as TNB specifies during the application for supply process.
This is especially critical for medium voltage and High Voltage Customers.
Specific Requirements
Customers shall take into consideration the following specific protection practices of TNB in designing their installation.
-Maximum clearance times (from fault current inception to fault clearing)must be within the limits established by TNB in their short circuit rating policy for the distribution system.
-Auto-resoling or sequential switching features may be used on TNB ‘s distribution system .TNB will provide details on the operating sequence utilized for the supplies on the proposed installation so that the customer can plan for this in the design and protection of his facility.
-On some TNB’s distribution system ,certain types of faults may cause disconnection of one phase only of a three phase supply.
1)Basic requirements
Basic requirements is that the customer’s arrangements for protection at the connection point ,including types of equipment and protection settings ,must be compatible with standard practices on the TNB’S system and be as TNB specifies during the application for supply process.
This is especially critical for medium voltage and High Voltage Customers.
Specific Requirements
Customers shall take into consideration the following specific protection practices of TNB in designing their installation.
-Maximum clearance times (from fault current inception to fault clearing)must be within the limits established by TNB in their short circuit rating policy for the distribution system.
-Auto-resoling or sequential switching features may be used on TNB ‘s distribution system .TNB will provide details on the operating sequence utilized for the supplies on the proposed installation so that the customer can plan for this in the design and protection of his facility.
-On some TNB’s distribution system ,certain types of faults may cause disconnection of one phase only of a three phase supply.
20/4/2010
Go through substation categories, type and design. There are 4 types of substation:
PMU-Pencawang Masuk Utama(Transmission Main Intake)
PMU is the interconnection point of 132kv or 275kv to the distribution network .The standard transmission capacity and voltage transmission provided at the PMU are as follows:
-132/33 kv,2*90mva
-132/22 kv,2*90mva
132/11 kv,2*30mva
PPU-Pencawang Pembahagian utama(Main Distribution Substation)
PPU normally applicable to 33kv for interconnection g 33kv networks with 11kv networks. It provides capacity injection into 11kv network through a standardized transformation of 33/11 kv,2*30mva
SSU-Seksyen suis utama(Main Switching Station)
SSU at 33kv,22kv,and 11kv are established to serve the following function:
To supply a dedicated bolts customer(33kv,22kv,11kv)
To provide bulk capacity injection or transfer from a PPU/PMU to a load center for further localized distribution.
P/E-Pencawang Elektrik(Distribution Substation)
P/E are capacity injection points from 11kv,22kv and sometimes 33kv systems to the low voltage network(415v,240v)Typical capacity ratings are 1000kva,750kva,500kva,300kva and 100kva.
Conventional sub-station designs are of indoor type(equipment housed in a permanent building)and outdoor type(Ground-mounted or Pole mounted)
Compact substation (11/0.45kv)has limited application and is to be strictly applied in selective situations under the following circumstances.
-System reinforcement projects for highly build up areas where substation land is difficult to acquire.
-Dedicated supply to a single or limited group of low voltage customers after careful consideration of future expansion needs of the distribution network.
The main reasons for the above application criteria are as follows :
-Compact design reduces future system flexibility in terms of network expansion.
-Compact design features ,which limits the capacity of outgoing circuits.
PMU-Pencawang Masuk Utama(Transmission Main Intake)
PMU is the interconnection point of 132kv or 275kv to the distribution network .The standard transmission capacity and voltage transmission provided at the PMU are as follows:
-132/33 kv,2*90mva
-132/22 kv,2*90mva
132/11 kv,2*30mva
PPU-Pencawang Pembahagian utama(Main Distribution Substation)
PPU normally applicable to 33kv for interconnection g 33kv networks with 11kv networks. It provides capacity injection into 11kv network through a standardized transformation of 33/11 kv,2*30mva
SSU-Seksyen suis utama(Main Switching Station)
SSU at 33kv,22kv,and 11kv are established to serve the following function:
To supply a dedicated bolts customer(33kv,22kv,11kv)
To provide bulk capacity injection or transfer from a PPU/PMU to a load center for further localized distribution.
P/E-Pencawang Elektrik(Distribution Substation)
P/E are capacity injection points from 11kv,22kv and sometimes 33kv systems to the low voltage network(415v,240v)Typical capacity ratings are 1000kva,750kva,500kva,300kva and 100kva.
Conventional sub-station designs are of indoor type(equipment housed in a permanent building)and outdoor type(Ground-mounted or Pole mounted)
Compact substation (11/0.45kv)has limited application and is to be strictly applied in selective situations under the following circumstances.
-System reinforcement projects for highly build up areas where substation land is difficult to acquire.
-Dedicated supply to a single or limited group of low voltage customers after careful consideration of future expansion needs of the distribution network.
The main reasons for the above application criteria are as follows :
-Compact design reduces future system flexibility in terms of network expansion.
-Compact design features ,which limits the capacity of outgoing circuits.
19/4/2010
Go through sub-transmission capacity planning(STCP 2008-2013;Kedah state),which is encompasses the following:
capacity/demand balance analysis of sub transmission capacity under n-1 firm capacity and group firm operational criteria.
Performance analysis of sub-transmission level and distribution network within the supply zone in terms of loading effects under normal and contingently load transferability and security level.
Summary of distribution development options related to sun-transmission capacity utilization within supply area.
Proposed PMU plant up for the planning horizon.
This report presents the findings and recommendations on PMU plant up equipment for the supply zone(SZ) up to the planning horizon 2013.
capacity/demand balance analysis of sub transmission capacity under n-1 firm capacity and group firm operational criteria.
Performance analysis of sub-transmission level and distribution network within the supply zone in terms of loading effects under normal and contingently load transferability and security level.
Summary of distribution development options related to sun-transmission capacity utilization within supply area.
Proposed PMU plant up for the planning horizon.
This report presents the findings and recommendations on PMU plant up equipment for the supply zone(SZ) up to the planning horizon 2013.
18/4/2010
Go through Load Desegregation.
The objectives of Load Desegregation viewed from the perspective of distribution planners are as follows:
The information and data will form the basis for transmission capacity planning and development.
The data will equally provide the initial data for medium term distribution system reinforcement planning and system operational study-in terms of constraints, limitations and opportunities .
The data will also serve us the basis to determine and distribution main-intake(PPU) planning to transmit transmission intakes 33kv capacity to satisfy localized development needs.
Results of the Load Desegregation will greatly indicates the pace of transmission as well as distribution system development initiatives in the next 15 years.
The objectives of Load Desegregation viewed from the perspective of distribution planners are as follows:
The information and data will form the basis for transmission capacity planning and development.
The data will equally provide the initial data for medium term distribution system reinforcement planning and system operational study-in terms of constraints, limitations and opportunities .
The data will also serve us the basis to determine and distribution main-intake(PPU) planning to transmit transmission intakes 33kv capacity to satisfy localized development needs.
Results of the Load Desegregation will greatly indicates the pace of transmission as well as distribution system development initiatives in the next 15 years.
15/4/2010
Go through Load Forecast which is used as a means of predicting future electricity demand or sales growth based on historical data.
The future electricity demand information derived will assist system planners in proposing new equipment and facilities as well as reinforcing and upgrading the existing system to meet the increasing demand.
Accurate ,Reliable and Defendable forecast will help planners in making prudent investment decision for the system expansion ,reinforcement and new plant-up.
The forecast horizon has been defined in accordance to the upcoming Malaysian Distribution code:
Short term:1-2 years
Medium term:3-5 years
Long term:6-10 years
Short term forecast is useful for operational planning and capital budgeting as well as for material procurement planning requirements.
PPU plants up proposal and Distribution network planning will use short to medium term forecast.
Alternatively ,sub-transmission capacity planning or PMU planning utilizes medium-term forecasts.
Long term provides inputs and lead time for generation plats ups ,substation sites and associated way leave identification and acquisition.
The future electricity demand information derived will assist system planners in proposing new equipment and facilities as well as reinforcing and upgrading the existing system to meet the increasing demand.
Accurate ,Reliable and Defendable forecast will help planners in making prudent investment decision for the system expansion ,reinforcement and new plant-up.
The forecast horizon has been defined in accordance to the upcoming Malaysian Distribution code:
Short term:1-2 years
Medium term:3-5 years
Long term:6-10 years
Short term forecast is useful for operational planning and capital budgeting as well as for material procurement planning requirements.
PPU plants up proposal and Distribution network planning will use short to medium term forecast.
Alternatively ,sub-transmission capacity planning or PMU planning utilizes medium-term forecasts.
Long term provides inputs and lead time for generation plats ups ,substation sites and associated way leave identification and acquisition.
14/4/2010
I have go through Electricity Supply Application Handbook and more understand about TNB’s core activities are in Generation ,Transmission , and Distribution of electricity which are being handled by its subsidiaries:
1)TNB Generation Sdn Bhd
2)TNB Transmission Network Sdn Bhd
3)TNB Distribution Sdn Bhd
Currently I’m doing my internship in TNB Distribution Sdn Bhd .TNBD divides its core activities into 3 main areas namely customer service(CS),network service(NS), and support service(SS).
Customer Service(CS):includes functions pertaining to application for supply ,billing &collection ,upgrading of services ,Kedai Tenaga Elektrik Bestari ,the Call Management Centre and other customer related activities.
Network Service(NS):Plans ,designs ,contracts ,operates and maintains the system that delivers supply to the customer.
Support Service(SS):provides synergy with Customer service and Network Service to ensure the smooth functioning of TNBD’s core activities .The support departments at the heart quarters includes Business Management ,Finance ,Engineering ,Human Resource Management ,Materials Resource Management ,Strategic Management and Customer solutions.
1)TNB Generation Sdn Bhd
2)TNB Transmission Network Sdn Bhd
3)TNB Distribution Sdn Bhd
Currently I’m doing my internship in TNB Distribution Sdn Bhd .TNBD divides its core activities into 3 main areas namely customer service(CS),network service(NS), and support service(SS).
Customer Service(CS):includes functions pertaining to application for supply ,billing &collection ,upgrading of services ,Kedai Tenaga Elektrik Bestari ,the Call Management Centre and other customer related activities.
Network Service(NS):Plans ,designs ,contracts ,operates and maintains the system that delivers supply to the customer.
Support Service(SS):provides synergy with Customer service and Network Service to ensure the smooth functioning of TNBD’s core activities .The support departments at the heart quarters includes Business Management ,Finance ,Engineering ,Human Resource Management ,Materials Resource Management ,Strategic Management and Customer solutions.
Tuesday, April 13, 2010
13-04-10
NERCC Seberang Perai
Tired ~~
Need to record so many data/value from the load bus
There are two types of data/value needed to record:
1)morning
2)night
If the value is not specified,haiz!!!! it will take times because i need to do some comparison (31 day -March for each hour)~~
After few hours,we have completed our task~~but it is quite late~~
We reached Alor Star around 615pm..
Today is my first day work overtime with no salary!!
Thank's Bali fetch me to Prai~~
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