summer training at secco
DESCRIPTION
Summer Training ReportTRANSCRIPT
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King Faisal University
College of Engineering
Department of Electrical Engineering
Summer Training at Saudi Electricity Company Report
By
Name: Hasan Saeed Al-Qadheeb
ID#: 210003380
15/08/2013
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Table of Contents: Page #
1. Introduction ………………………………………………………………………….4
2. Brief History of the Company ………………………………………………………4
3. Technical and practical information gained ……………………………………….5
3-1. Power Plant (Generating Station) ………………………………………...5
3-2. Power Transmission ……………………………………………………….5
3-3. Power Distribution ………………………………………………………...6
3-4. Electricity System in SEC …………………………………………………6
3-5. Substation …………………………………………………………………..7
3-6. Ring Main Units (RMU) …………………………………………………...8
3-7. Low Voltage Panel ………………………………………………………...10
3-8. Mini Pillar …………………………………………………………………11
4. Conclusion …………………………………………………………………………...12
5. Appendix ……………………………………………………………………………..13
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List of Figures Page #
Figure 1: Power Plant ………………………………………………………………….5
Figure 2: Simple Electricity System …………………………………………………...6
Figure 3 Electricity System of SEC ……………………………………………………7
Figure 4: Substation (Transformer + RMU) ………………………………………….8
Figure 5: Example for the substation location diagram ………………………….......8
Figure 6: oil switch (RMU) ……………………………………………………………..9
Figure 7: Two types of SF6 switch (SF6 RMU) ……………………………………….9
Figure 8: Open LVP ……………………………………………………………………10
Figure 9: Mini Pillar …………………………………………………………………...11
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1. Introduction:
College of Engineering in King Faisal University gives an opportunity to
Its senior students to do summer training course in one of the industrial companies.
Summer training offer students an opportunity to get some concrete work experience and
be able to try out what it's actually like working in a particular career. So, I did my
summer training in Saudi Electricity Company (SEC). Saudi Electricity Company is a
merger of all Saudi electricity companies in the central, eastern, western and southern
regions into a single joint stock company providing generation, transmission and
distribution of safe and reliable electric services to customers in the Kingdom of Saudi
Arabia.
I spend 8 weeks working in the company from 15/06/2013 to 07/08/2013. I
worked in 4 different departments in the company as the following:
Two weeks at: Department of Testing and Identification of Faults.
Two weeks at: Department of Independent Generating Stations.
Two weeks at: Department of Operation of High Voltage (HV) Networks.
Two weeks at: Department of Emergency and Network Failures.
**See “Appendix A” for more details.
During my summer training I learned a lot of information about the company and the
electricity networks in Saudi Arabia, so in this report am going to show some important
information and details that I learned.
2. Brief History of the Company:
The first Saudi Consolidated Electricity Companies (SCECO) was (SCECO-East)
which created in 1976 (1396/1397 AH). This was followed in 1979 (1399/1400 AH) by
SCECO-South. Electricity for the southwest is provided by another consolidated
company, and the central region is served by SCECO-Central.
The General Electricity Corporation (GEC) had overall responsibility for the
Kingdom's electricity system and had direct responsibility for the provision of electrical
supplies to rural areas not then covered by the consolidated companies. The GEC
represented the government equity holdings in all the independent electricity generating
companies and was a source of finance for those companies' capital requirements.
In 1998, the Government announced the reorganization of the electricity sector by
establishing a stock market company, named the Saudi Electric Company (SEC), through
the merger of all the electricity companies operating in the Kingdom.
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3. Technical and practical information gained:
In this section in going to present some information that I learned during the
summer training period.
3-1. Power Plant (Generating Station):
A power plant is an industrial facility for the generation of electric power.
At the center of nearly all power stations is a generator, a rotating machine that
converts mechanical power into electrical power by creating relative motion
between a magnetic field and a conductor. The energy source harnessed to turn
the generator varies widely. It depends chiefly on which fuels are easily
available, cheap enough and on the types of technology that the power company
has access to. Most power stations in the world burn fossil fuels such as coal, oil,
and natural gas to generate electricity. Figure 1, shows the component of a power
plant
Figure 1: Power Plant
3-2. Power Transmission:
Here in this part the generated electricity is transfers from the Power Plant
to the main supply points throughout the eastern province by using transmission
lines which are the connecting links between the generating stations and the
distribution systems. Electricity is transmitted at high voltages (115 kV or above)
to reduce the energy lost in long-distance transmission. Power is usually
transmitted through overhead power lines. Underground power transmission has a
significantly higher cost and greater operational limitations but is sometimes used
in urban areas or sensitive locations. The power system looks like what shown in
Figure 2.
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Figure 2: Simple Electricity System.
3-3. Power Distribution:
The objective of Power Distribution System is to deliver the Electrical
power to Customers in safe, reliable and most economical way. This means that a
Customer receives a supply of Electrical power required by him at the time and
place at which he can use it. Several parameters of an Electricity supply such as
frequency, continuity of supply, voltage level, etc. should be within allowable
limits to ensure that the Customer obtains satisfactory performance for his
electrical equipment while ensuring that the demands of the Customers continue
to be met, the capital and operating costs of doing so should be reduced minimum
as possible.
3-4. Electricity System in SEC:
The power plants generate a standard voltage of 13.8 kV. Then the 13.8
kV amplified to be 230/380 kV using a step up transformer in the bulk supply
point. The 230 kV is used in the near cities whereas the 380 kV is provided if
necessary to be transmitted to far cities. This means that the 230 kV most exist in
each bulk supply point. After the transmission, the 230 kV is then converted to 69
kV using step down transformers. In the grid station, the 69 kV is converted to
13.8 kV and in turn it is transmitted to substations through Breakers. The
substation has a transformer which converts the 13.8 kV to low voltages of
220V/380V or 127V/220V. The low voltage is distributed from the low voltage
panel. Finally, the low voltage is delivered to the customer by using a mini pillar.
See Figure 3.
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Figure 3 Electricity System of SEC
3-5. Substation:
The substation is a medium voltage (MV) unit. The medium voltage is
13.8 kV coming from the grid station. This 13.8 kV is distributed to substations in which
they have step down transformers. The low voltage starts just after the transformer in the
substation. The substation uses a step down transformer that transforms the 13.8 kV to
low voltages (127 V/ 220 V). Substation is formed by the ring main unit (RMU),
transformer, and the low voltage panel. See figure 4 for example for the substation. SEC
has a complete maps and location diagram of the substations in alhasa see figure 5 as an
example. The substation name is taking the transformer name. In the next section I will
talk about the RMU.
Customer
Meter
Mini Pillar
Low Voltage Panel
Substation
13.8 kV to 127 V / 220 V
Breaker
Grid Station
69 kV to 13.8 kV
Step Down Transformer
230/380 kV to 69 kV
Bulk Supply Point
13.8 kV to 230 kV and 380 kV
Power Plant
13.8 kV
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Figure 4: Substation (Transformer + RMU)
Figure 5: Example for the substation location diagram
3-6. Ring Main Units (RMU):
The ring main unit (RMU) is a switchgear that takes the 13.8 KV cable,
links it to the transformer in the substation, and also links the 13.8 KV cable to another
substation. This means that the ring main unit has an incoming 13.8 KV cable, an
outgoing 13.8 KV cable, and a local cable. The incoming cable is a cable linked to the
substation by another substation whereas the outgoing cable is a cable linked from the
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substation to another substation. The local cable is used by the substation from the
incoming cable. There are two types of switchgears used at the company network. They
differ in the used insulation substances which are the oil switch, and the Sulfur
Hexafluoride (SF6) switch. See figure 6 for the oil switch and figure 7 for the SF6
switches.
Figure 6: oil switch (RMU)
Figure 7: Two types of SF6 switch (SF6 RMU)
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3-7. Low Voltage Panel:
The low voltage panel (LVP) is a panel that distributes the output
cables/circuits of the transformer. Each circuit from the low voltage panel contains the
red phase, yellow, and the blue phase in addition to the neutral cable which is black. The
low voltage panel output number of circuits depends on the transformer used in the
substation. The transformer output cables are connected to the bus bar of the low voltage
panel and from the bus bar, the low voltage circuits are provided such that each circuit
has a circuit breaker of 400A for each phase in the circuit. See figure 8 for opened LVP.
Figure 8: Open LVP.
3-8. Mini Pillar:
The mini pillar is a panel that takes one cable/circuit from the low voltage
panel and provides at most six circuits to divide them among at most six customers.
Figure 9 shows a mini pillar which has four connected circuits. The circuit breakers of the
mini pillars are of 200 A for each phase in a circuit. Sometimes one customer needs two
circuits from the mini pillar also when customers need higher ampere, a circuit from the
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low voltage panel is provided without using the mini pillar. There are at most two mini
pillars that can be connected together and there is two phase and one neutral cables in
each circuit, that are connected from the mini pillar to a meter because each customer
needs this specification to be energized in the low voltage.
Figure 9: Mini Pillar
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4. Conclusion:
Finally, my summer training was very interesting and very efficient. I learned a
lot of practical things that I described previously in this report. Also I apply the theorem
that I studied in the college. The employees was so friendly with me, they help me to
understand everything that I need. So I took good knowledge about power plant,
transmission lines, and substations, which are the most important sections for any electric
company.