21/4/2010

Yuhuu~

I read the Distribution Planning Guideline Handbook. One of the topic is about MV Network Configuration. The MV Distribution Network in TNB operates at voltages of 6.6, 11, 22 and 33 kV
and interlinks the transmission system and the LV distribution system.

TYPE OF NETWORK CONFIGURATION
There are three basic network configurations that are commonly in use are;
(a) the radial circuit,
(b) the mesh circuit, and
(c) the loop circuit.



Performance of some common network configuration with respect to several different sets of characteristics as listed below:-
• Construction characteristic
• Operation characteristic
• Maintenance characteristic

The salient features of the various network configurations under consideration are
as follows:-
• Radial circuit
• Mesh circuit
• Loop circuit from same ppu/pmu
• Loop circuit from different ppu/pmu
• Loop via switching station (n+1 grouping)
• Petal configuration
• Bulk supply interconnector configuration


Today, my focus suggested by my supervisor is the Petal Configuration.
• The “petal configuration” is one method to improve reliability and security of supply.
• The “petal configuration is developed by interconnecting a loop circuit form one PPU/PMU to a loop circuit from another PPU/PMU via a switching station or the bus-section of a normal substation.
• Individual cable loops are operated in a “close loop” arrangement with 50% loading level.
• All circuit breaker substations are installed with unit protection for cable and SCADA supervisory system for remote switching
• An off-point is maintained at the switching station or bus-section.

The main advantages of this network configuration are:-
• No supply interruption due to single cable fault outage
• Full feedback even if one of the PPU/PMU outage
• SCADA system to detect cable fault and perform remote switching

The disadvantage of this network configuration is:-
• the inherent high cost of installing SCADA system and circuit breaker substations.

20/4/2010

Yuhuu~

I studied about Distribution Network Master Plan (DNMP).It is part of a distribution planning cycle and process to assess the future (planning horizon: 1-3 years for 11kV and 1-5 years for 33kV) distribution system conditions and identify system development options for compliance to the distribution system performance objectives or defined performance targets.

The key objectives of this annual planning exercise for distribution system planners are:

1) To provide fact-based assessment of network performance (existing and future years within planning horizon).

2) To review system performance objectives/targets.

3) To review TNB Distribution planning and development strategies, policies if necessary.

4) To develop & test network solutions in meeting system performance objectives.

5) To identify and select best network development options.

6) To identify medium-term system development and reinforcement CAPEX for a supply zone and state.

Overall, the system planning process and preparation of a master plan undertaken in

DNMP would provide a comprehensive analysis and documentation of the current and future system performance status as well as the investment required to meet the targeted system performance objectives.

The DNMP will encompass the following tasks and analyses for a supply zone:

1) Network modeling of all subsystems (33kV)

2) Load scaling based on disaggregated demand forecast.

3) Load flow, security and contingency analyses.

4) Short circuit analysis.

5) Determination of target networks founded on best network solutions.

6) Recommendation of network expansion and reinforcement projects.

7) Preparation of summary report.

DNMP Methodology

The methodology or approach adopted for 33kV DNMP is as outlined in Appendix 1. A brief overview of the methodology and tasks undertaken in this planning exercise is shown in the flow-chart below.

that's all for the day~

bye

19/4/2010

Yuhuu~

Today I revised the next topic after Load Disaggregation which is Sub-Transmission Capacity Planning (STCP)

Objective

Represents the finding and recommendations on PMU Plant-up requirements for the supply zone (SZ) up to the planning horizon for certain year.

Scope

STCP encompasses the following:

1) Capacity / demand balance analysis of sub-transmission capacity under n-1 firm capacity and group firm operational criteria.

2)Performance analysis of sub-transmission level and distribution network within the supply zone in terms of loading levels under normal and contingency, load transferability and security level.

3)Summary of distribution development option related to sub-transmission capacity utilization within supply area.

4)Proposed PMU plant-up for the planning horizon.

that's all for the day
bye~

18/4/2010

Yuhuu~

Today, I have revised about Load Disaggregation.

The objectives of load disaggregation viewed from the perspective of distribution planners are as follows:

1)The information and data will form the basis for transmission capacity planning and development.

2)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.

3)The data will also serve as the basis to determine on distribution main-intake (PPU) planning to transmit transmission intakes’ 22kV capacity to satisfy localized developments needs.

The result of the load disaggregation will greatly indicates the pace of transmission as well as distribution system development initiatives in the next 15 years. As such, some recommendations or proposals are therefore summarized at the end of the report as necessitated by the prevailing growth scenario ad other objectives in system development.
that's all for the day
bye~

15/4/2010

Yuhuu~

Today, I have reviewed about TNB Distribution 33kV planning cycle and I put my focus on load forecast. The load forecast is used as a means of predicting future electricity demands 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 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 plant-up proposal and distribution network planning will use short-to-medium term forecast.

Alternatively, sub-transmission capacity planning or PMU planning will utilizes medium-term forecast.

A long term forecast are strategic in nature and being used to provide inputs and lead time for generation plants ups, substation sites and the associated way leave identification and acquisition.

14/4/2010

yuhuu~

Since everybody in the department were too busy this week and some of them were sent to ILSAS for a course,especially Kak Ina, then in order to fill the free time with some beneficial stuffs. Soo, I have to go through electricity supply application handbook given by kak ina before she left to ILSAS and I became more understand about TNB’s core activities which are in generation, transmission, and distribution of electricity which are being handled by its subsidiaries which are TNB Generation Sdn Bhd, TNB transmission Network Sdn Bhd, and TNB Distribution Sdn Bhd

As I am doing my internship in TNB Distribution Sdn Bhd, I can tell that TNB Distribution Sdn Bhd divides its core activities into three main areas which are Customer service (CS), Network Service (NS) , Support service (SS).

Each area has their respective functions in order to pertaining application for supply, providing electricity to customer upgrading of services and others.

that's all for the day~
bye

13/4/2010

Yuhuu~

Today, I went to NERCC (North Eastern Regional Control Centre). I have learnt how to take load reading which is used for load forecast planning. Load reading is a monthly event and it is useful to predict expenses in the future by taking the load reading for each place in the north and eastern. NERCC is placed in the TNB building level 5 in Seberang Prai, Pulau Pinang.

NERCC acts as switching control centre. It controls all the switching of the PPU and PMU (33kV and 11kV). The technician talked about SCADA (Supervisory Control and Data Acquisition) system it to us. They said, “SCADA ni bertujuan memastikan bekalan elektrik ke Wilayah Ekonomi Koridor Utara (NCER) dan Wilayah Ekonomi Pantai Timur (ECER) mencukupi untuk menampung kepesatan aktiviti ekonomi di kawasan berkenaan. Contohnya, system ni dapat mengesan sebarang kerosakan atau masalah berkaitan bekalan elektrik bagi kawasan terbabit dan tindakan memulihkan bekalan akan dilakukan dalam jangkamasa yang cepat. Kalau ada kerosakan kecil, TNB boleh mengambil tindakan awal untuk memulihkan keadaan bagi mengelakkan kerosakan menjadi lebih buruk.”

Pulau Pinang became the second RCC (Regional Control Centre) in Malaysia after Bangsar in Port Klang. Other than that, MSRCC (Metro South Regional Control Centre) in Bangsar distribute the electricity supply to the south and western part of Malaysia.

In the PMU and PPU, there is RTU (Remote Terminal Unit). All the value measured and the data of the load is connected to it and the data will be sent through transducer in the RTU to RCC.

We can get the idea by finding the value from the load reading. the method of reading the value ca become tedious if the value given is not specified whether it is in the morning or night. So, we need to do a comparison at specified time throughout the month.






Then we went back home. We finally reached at the company at 6.10 pm. So from the punch card, it’s looked like we did an overtime work with “no salary”.

that's all for today
bye~

12/4/2010

Yuhuu~

I came early today to my office early than the previous day...at 7.55 am. Since everybody is still busy with their own work, so I write something about yesterday’s progress in my logbook. Then Mr Paudzi briefly explained to us about Power Quality. This subject is very important and essential in working in TNB. He also explained us about background, application and problem of Power Quality.

For more information, we searched about power quality from TNB's intranet connection. It was quite easy to understand because it provides us with some animation of the electricity movement.

Then he explained about a project that he is dealing with right now .

Then, after an hour, he called us again and he told us about what is the project that

8/4/2010

yuhuu~

We have been expained briefly about the power system protection.
There are 4 basic components in protection system-
1)Translay 11kv
2)Solkor R 11kv
3)Solkor RR 38kv
4)Solkor N-current Differential

After breakfast, we went to Pencawang Masuk Sementara 132/11 kv Taman Intan, Sungai Petani which is still under construction. Encik Paudzi once again explained to us how to read the transformer's reading but i am still confused because we are in a rush, so i couldnt ask more about the reading stuff. Below are some of the picture of Pencawang masuk Sementara of Taman Intan, Sungai petani.

my first time viewed this thing from this angle...excited!

this is the picture of the PMU of Taman Intan. It is located near to PMU Taman Intan. but it is still under construction.

that's all for today~

11/4/2010

Yuhuu~

Today, early in the morning, I have been briefly explained about how AutoCAD software works in the Planning Department by Abang Jef. In this department, AutoCAD Map 3D is our major programme. It is based on AutoCAD and contains all of that program’s functionality, as well as its own powerful tools designed for mapping and geographic information system (GIS) professional.

Today I have no site visit and it was quite bored because I just need to stay in the office while reading the Distribution Protection-Coordination of Protective device, and Power Quality borrowed by Mr. Mazlan while fulfilling my free time. Anyway, they are some of the elective subject offered in my University especially for EP student.

In my conclusion, today is such a boring day!

that's all for today~

bye

2nd & 3rd Day

yuhuu~

~2nd day~

Today, me and my colleague learned about PSSU(Power System Simulator for Utilization) and PSS/Adept(Advanced Distribution Engineering Productivity Tool) which used to model,simulate and analyse network in a distribution system.
and we have been assigned an assessment of Pulau Pangkor System Schematic Diagram .We need to know about the node,voltage(kV),static load(kva,pf),input data(from-to),Length(km) and size needed in order to get the output. we took 4 hours to finish the assessment. There were some errors which we can see the diagram became red in colour, so, in order for us to fix the system, we need to alter the system until the line become green in colour. moreover, we have to suggest about the best point in the network during breakdown happen.
an utility company also need to get the power factor equal or almost 1 to reduce losses otherwise they can install the capacitor bank.
it was cool after we managed to finish it..

Kak Ina was tutoring us about the PSSU/ADEPT software

Lim was struggling to construct the schematic diagram

me too~

this one is still not finish.the system is still not stable yet.in order to make it finish, all the line and nodes should be in a green colour. after do some changes, it's done!
and i forgot to take the picture.



~3rd day~

Today, i went to my first site visit at PPU at Sik.

the plan to the 1st site visit (PPU 33/11 kV Sik)

reached our destination after 30 minutes journey

transformer's control system


while Encik Din was explaining to us about the switch,he said that an overloaded circuit is the primary reason for a breaker tripping and occurs when a circuit is has more connected electrical load than it is supposed to have. When more current runs through the circuit than the circuit was intended to take, the circuit breaker is designed to, well, "break the circuit."
after the explaination, suddenly the green lamp turned on. this means that trip happened. so they call the AP (authorized person) to check and fix the problem. the feedback from the AP, he said that it is because of the tnb people hacked the groud to install cable.

this is the Authorized Person (AP)

This is the outdoor PPU System. there are some important parts of the PPU System 33/11 kV.

Power Transformer

Power Transformer's detail

Power Transformer: the right part with the brown disk is the incomer voltage (33kV) cable and the left part with some oily cable is the output voltage (11kV). the oily cable is because of the leakage.

the output cable

Lighting Arrester

Breakers(Red ,Blue and Yellow colour)

Current Transformer

Line Oscillator

The insulator : the disk in green. it can carry 11kV. As we can seefrom the picture, there are 3 disk attached at the end of the cable. so we can say that this PPU is 33 kV.

This is Encik Din who explained a lot about PPU to us for today's site visit.

In the evening, Kak Ina brought us to the place in the picture above. Its is smaller than the previous PPU.


Kak Ina couldn't unlock the hedge


Transformer(front view)
Trasmittion from PMU Sg Tiang to Bhg Pembahagian Batu Kemelung
it is step down from 33 kV - 415 V.

that's all
bye2~!

1st entry~

yuhuuu~

haaaa.....kawan2 skalian..meh nk habaq mai sat..
arini, ari 1st aku jd konon2 pekerja TNB...haha..tp x mcm pekerja pon, student lagi padahal..cewah..hehe

smlm aku dah plan nk tdo awal..so,aku tido la awal. tp masalah nye aku xleh nk tdo la plak..maklumla sblom ni dah terbiase stay up lewat mlm time final utk study+facebook.
on the way nk tdo tu aku godek2 la atas katil n aku rase2 la, aku mcm terlelap pukol 3.30 mcm tu.

then aku terjage la tym suboh sbb mak aku dah memekak2 dah kat telinga aku...namun begitu nafsu tidor ku sungguh la tegar! hahahhaa....aku tdo lagi...skali mak aku mngamuk bebel2 mcm2 ntah ape die ckp pon aku dah x dgr, aku pon terus la ke toilet...gosok gigi sambil mampu membuka mata sebelah je..haha

pastu sesudah settle bersiap sume aku pon g la kat opis TNB kat loqstaq tuh dgn penuh smgt LI..nk smpai sane cume 5 minit je kalau nek kete dr umah aku..kalau ngan moto xyah ckp la...kalau ngan jalan kaki??? MESTILA AKU TANAK!!!..hahhaa

sampai sane je aku kesipu2an xknal sape2...skali tgk ade sorg amoi nih..dak uniten jugak tp aku xknal name die...bile tego die td die kate name die Lim chia ying KOT.....panggil je lim.
kitorg due je dr uniten yg buat practical kat sne...tp yg buat practical kat sane bukan ade org lain pon...mmg ade kitorg due je..hahaha..tp layan jela, jd skema skit aku.haha

arini kitorg dah start blaja dah..aku kne blaja pasal planning cycle arini...mmandangkan lanning cycle ni agak pntg dlm TNB distribution, so mmg kne blaja jugak la..tp basic mnde alah nih ialah subjek power system la...ingatkan lpas final xyah nk pk pasal power sys dah..skali mcm kne further study plak...tp perasaan die agak lain kali nih..kalau dlm klas blaja mkalau x paham tuh mmg malas nk blaja skit la..tp bile kat tempat keje td..cheh, ttbe rase ingin tahu sgt tinggi...haaa...dah berubah nampaknye aku..proses pematangan kah? layann~

some of the poypic :


hahaha......agak poyo d ctu kan? ape2 aje..haha


planning cycle~


ni la die Lim Chia Ying tuh..die budak EE

time ni dah kol 4 dah..haha


itu sje untuk kali ini
bye!