1. NO. Content Page
Chapter one Introduction 2
1.1 Energy sector in Palestine 2
1.2 Power system 3
1.3 Load flow analysis 4
1.4 Etab power station 5
1.5 SCADA System 6
1.5.1 SCADA hardware 6
1.5.2 SCADA software 6
1.6 About project 8
Chapter two Elements of the network 9
2.1 Distribution transformer 10
2.2 Medium voltage lines 11
2.2.1 Over head lines 11
2.2.2 Underground cables 12
2.2.3 Daily load curve 12
Chapter three Maximum Load Case Analysis 13
3.1 Maximum load case 14
3.2 Problems 14
3.3 The Maximum Load Case Improvement 15
3.4 Overloaded Transformers Problem 17
3.5 New connection Point Study for the maximum load
case
18
3.6 Improving the network with the new connection
point
19
Chapter four Minimum Load Case Study 20
4.1 Minimum Case Study 21
4.2 Minimum Load Study After The Connection Point
And Solving Overloaded Transformers Problem
22
Chapter five Economical Study 24
Chapter six Monitoring System 27
6.1 Monitoring System 28
6.2 Current Measurement 28
6.3 Voltage Measurement 29
6.4 Power Factor Measurement 31
6.5 Frequency Measurement 33
6.6 The Remote Terminal Unit (RTU) 34
Appendices Tables 36
References 101
3. Page 2
1.1Energy Sector in Palestine
Energy sector in Palestine faced many difficulties because of occupation. Till now
there is no unified power system in Palestine. Most of electrical energy depends on
IEC Company except Jericho which connected with Jordan and Gaza to Egypt
(17MW) through the interconnection project. The only generation plant is in Gaza
with generating capacity of 140MW. Distribution companies take the role of
distributing electricity in the different regions of Palestine.
The average annual growth rate of energy demand in west bank is 6.4%, and in Gaza
is 10% from 1999 to 2005. The following figure shows the growth pattern in West
Bank, Gaza Strip and the total Palestine forecast:
Fig. 1.1
The following table shows the forecast summary - peak demand (MW):
Table1.1
202520202015201020092008Year
1,7141,3471,059885845806Total
1,012809646548525502W.B.
701538413336320303Gaza
0
200
400
600
800
1000
1200
1400
1600
1800
2005 2010 2015 2020 2025 2030
Power(MW)
Year
Power Demand
Total
W.B.
Gaza
4. Page 3
1.2 Power System
The power system in general consists of these parts:
1. Generating station: And this part consists of
a. Generators in which electric power is produced by 3-phase alternators
operating in parallel. And usually electric power is generated at voltages of
12kv to 25kv.
b. Sub-station, where the power transformers step up the voltage to between
66kv 1000kv.
1. Primary transmission. The electric power at high voltages is transmitted by 3-
phase 3-wire overhead system to the outskirts of the city. This forms the primary
transmission.
2. Secondary transmission. The primary transmission line terminates at the
receiving station which usually lies at the outskirts of the city. At the receiving
station the voltage is reduced to 33kv or 22kv by step-down transformers.
3. Primary distribution. the secondary transmission line terminates at the sub-
station where voltage is reduced from the secondary voltage to the primary
distribution voltage usually 11kv could be 6.6kv 3-phase 3-wire .the 11kv lines
run along the important road sides of the city. And forms the primary
distribution.
4. Secondary distribution. The electric power form primary distribution line is
delivered to distribution sub-stations. These sub-stations are located near the
consumers localities and step down the voltage to 400v 3-phase 4-wire for
secondary distribution. And this forms secondary distribution.
5. Page 4
1.3 Load Flow Analysis
Load flow analysis is probably the most important of all network calculations since
it concerns the network performance in its normal operating conditions. It is
performed to investigate the magnitude and phase angle of the voltage at each
bus and the real and reactive power flows in the system components.
Load flow analysis has a great importance in future expansion planning, in
stability studies and in determining the best economical operation for existing
systems. Also load flow results are very valuable for setting the proper protection
devices to insure the security of the system. In order to perform a load flow study,
full data must be provided about the studied system, such as connection diagram,
parameters of transformers and lines, rated values of each equipment, and the
assumed values of real and reactive power for each load.
Bus Classification
Each bus in the system has four variables: voltage magnitude, voltage angle, real
power and reactive power. During the operation of the power system, each bus
has two known variables and two unknowns. Generally, the bus must be classified
as one of the following bus types:
1. Swing Bus
This bus is considered as the reference bus. It must be connected to a generator of
high rating relative to the other generators. During the operation, the voltage of this
bus is always specified and remains constant in magnitude and angle. In addition to
the generation assigned to it according to economic operation, this bus is responsible
for supplying the losses of the system.
2. Voltage Controlled Bus
During the operation the voltage magnitude at this the bus is kept constant. Also, the
active power supplied is kept constant at the value that satisfies the economic
operation of the system. Most probably, this bus is connected to a generator where
the voltage is controlled using the excitation and the power is controlled using the
prime mover control (as you have studied in the last experiment). Sometimes, this
bus is connected to a VAR device where the voltage can be controlled by varying the
value of the injected VAR to the bus.
3. Load Bus
This bus is not connected to a generator so that neither its voltage nor its real power
can be controlled. On the other hand, the load connected to this bus will change the
active and reactive power at the bus in a random manner. To solve the load flow
problem we have to assume the complex power value (real and reactive) at this bus.
6. Page 5
1.4 ETAP Power Station
ETAP Load Flow software performs power flow analysis and voltage drop calculations
with accurate and reliable results. Built-in features like automatic equipment
evaluation, alerts and warnings summary, load flow result analyzer, and intelligent
graphics make it the most efficient electrical power flow analysis tool available
today.
ETAP load flow calculation program calculates bus voltages, branch power factors,
currents, and power flows throughout the electrical system. ETAP allows for swing,
voltage regulated, and unregulated power sources with unlimited power grids and
generator connections.
Fig. 1.2
7. Page 6
1.5 SCADA System
SCADA (supervisory control and data acquisition) generally refers to industrial
control systems (ICS): computer systems that monitor and control industrial,
infrastructure, or facility-based processes, Industrial processes include those of
manufacturing, production, power generation, fabrication, and refining, and may run
in continuous, batch, repetitive, or discrete modes.
1.5.1 SCADA hardware.
A SCADA system consists of a number of remote terminal units (RTUs) collecting field
data and sending that data back to a master station, via a communication system.
The master station displays the acquired data and allows the operator to perform
remote control tasks.
The accurate and timely data allows for optimization of the plant operation and
process. Other benefits include more efficient, reliable and most importantly, safer
operations. These results in a lower cost of operation compared to earlier non-
automated systems.
On a more complex SCADA system there are essentially five levels or hierarchies:
Field level instrumentation and control devices.
Marshalling terminals and RTUs.
Communications system.
The master station(s).
The commercial data processing department computer system.
The RTU provides an interface to the field analog and digital sensors situated at each
remote site.
The communications system provides the pathway for communication between the
master station and the remote sites. This communication system can be wire, fiber
optic, radio, telephone line, microwave and possibly even satellite. Specific protocols
and error detection philosophies are used for efficient and optimum transfer of data.
The master station (or sub-masters) gather data from the various RTUs and generally
provide an operator interface for display of information and control of the remote
sites. In large telemetry systems, sub-master sites gather information from remote
sites and act as a relay back to the control master station.
1.5.2 SCADA software
SCADA software can be divided into two types, proprietary or open. Companies
develop proprietary software to communicate to their hardware. These systems are
sold as ‘turnkey’ solutions. The main problem with this system is the overwhelming
reliance on the supplier of the system. Open software systems have gained
popularity because of the interoperability they bring to the system. Interoperability
is the ability to mix different manufacturers’ equipment on the same system.
Citect and WonderWare are just two of the open software packages available in the
market for SCADA systems. Some packages are now including asset management
integrated within the SCADA system. The typical components of a SCADA system are
indicated in the next diagram.
8. Page 7
Fig 1.3
Key features of SCADA software are:
• User interface
• Graphics displays
• Alarms
• Trends
• RTU (and PLC) interface
• Scalability
• Access to data
• Database
• Networking
• Fault tolerance and redundancy
• Client/server distributed processing
9. Page 8
1.6About Project
The aim of this project is to do load flow study for the network of Tubas Electrical
Distribution Company (TEDCO). Then make a simulation for monitoring system for
the network. In this system the supervision part of monitoring systems will be done.
The electrical supply of the network is provided by IEC through 33KV overhead
transmission cables. The main connection point of the network is in Tyaseer with
capacity of 15MVA. And TEDCO distribute the electricity for the consumers. The
company is planning to add new connection point in Al Zawya.
TEDCO already has a small SCADA system. Which monitors the main lines of every
town, and for the transmission of the data from the RTUs they use SMS through
JAWWAL network. SMS method for the transmission of data is not reliable because
the system will not be online monitored they receive data every one hour also it is
expensive. The company plans to get internet through the power line, when they do
they will use it to monitor the network online.
11. Page 10
2.1 Distribution Transformers
The network consists of 141 distribution transformer (33∆/0.4Y (KV)). The
transformers range from 50KVA to 630 KVA the following table shows them in
details:
Table 2.1
Number of Transformers Rating (KVA)
4 50
15 100
19 160
43 250
33 400
27 630
Fig 2.1
12. Page 11
2.2 Medium Voltage Lines
2.2.1 Overhead Lines
The overhead lines used in the network are ACSR cables with different
diameters as the following table:
Table 2.2
Cable Name Cross
sectional area
(mm2
)
R (Ω/Km) X (Ω/Km) Nominal
Capacity (A)
Ostrich 150 0.19 0.28 350
Cochin 110 0.25 0.29 300
Lenghorn 70 0.39 0.31 180
Aprpcot 50 0.81 0.29 130
Fig 2.2
13. Page 12
2.2.2 Underground Cables
The underground cables used in the network are XLPE Cu (95 mm2
)
Table 2.3
Diameter (mm2
) R (Ω/Km) X (Ω/Km)
95 0.41 0.121
Fig 2.3
2.3 The daily load curve
The daily load curve of the network is shown in the figure below:
Fig2.4
The daily load curve shows the maximum and the minimum demand over the day,
these values help in the analysis of the network.
15. Page 14
3.1 Maximum load case
Considering the maximum demand in the daily load curve (fig2.4), it is found that the
maximum load equals two and half of the average load.
Then analyze the network using ETAP power station.
Cables lengths and resistances are shown in appendix 1.
The transformers loading are shown in appendix 2.
3.2 Problems
After the analysis of this case the following problems appeared:
Under voltage buses (Appendix 3).
Overloaded transformer (Appendix 4).
Power factor less than 92%
Table 3.1 summarizes the results of the network analysis in the maximum load case
(total generation, demand, loading, percentage of losses, and the total power
factor.)
Table 3.1
MW MVAR MVA % PF
Swing Bus(es): 16.755 7.474 18.346 91.33 lag.
Generators: 0.00 0.00 0.00 0.00
Total Demand: 16.755 7.474 18.346 91.33 lag.
Total Motor Load: 9.368 4.148
10.245
91.44 lag.
Total Static Load: 6.760 2.245
7.123 94.9 lag.
Apparent Losses: 0.627 1.081
1. The P.F in the network equal 90.75 and this value causes a lot of problem
specially paying banalities and this value must be (0.92-0.95) the P.F is
related to the current in the network according that when P.F is poor the
16. Page 15
current in the network is high this also can cause increasing the loses in the
network .
2. The PF improvement will show that the current will decrease, as a result the
losses will decrease
3. It is seen that the voltages on the buses are not acceptable. These voltages will be
less at the consumer side, under the machines rating which will cause a many
problems for the consumer.
3.3 The Maximum Load Case Improvement
There are different methods in order to improve the network to increase the
voltages and to put the PF within the range. Which will reduce the losses then the
problems for the consumer will decrease and the cost of KWH will decrease.
These methods are:
1. Tab changing in the transformer:
In this method the ratio of the taps on the transformer is changed in a range
of -5% to 5%. In this project the taps were changed to 5%. The location of the
changed taps is shown in Appendix 5
2. Adding capacitors:
The capacitors were added to reduce the reactive power which increases the
PF and the voltages of the buses. First the capacitor is added at the lowest
voltage bus then the one which have the larger voltage and so on. When
adding capacitors the PF should be lagging and more than 95%. The location
of the capacitor banks is shown in Appendix 6.
As mentioned adding capacitors will improve the PF.
The low PF cause problems as:
Higher Apparent Current.
Higher Losses in the Electrical Distribution network.
Low Voltage in the network.
Paying penalties.
Improving the power factor will avoid these problems.
17. Page 16
Capacitor banks will increase the PF as the following:
Where:
Qc: the reactive power to be compensated by the capacitor.
P: the real power of the load.
Ø old: the actual power angle.
Ø New: the proposed power angle.
According to the previous equation the value of capacitor banks needed to be added
in the network is:
PF old = 91.33%
PF new = 92% at least
Capacitor banks should be connected in delta connection on the low voltage side of the
transformer.
18. Page 17
Table 3.2 shows summary for the results after adding the capacitors:
Table 3.2
MW MVAR MVA % PF
Swing Bus(es):
17.423 6.946 18.757 92.89 lag
Total Demand:
17.423 6.946 18.757 92.89 lag
Total Motor Load:
9.368 4.148 10.245 91.44 lag
Total Static Load:
7.399 1.668 7.585 97.55 lag
Apparent Losses:
0.656 1.131
Voltages on the busses after improvement are shown in appendix 7.
3.4 Overloaded Transformers Problem
After the improvement of the network in the maximum case there is the problem of
the overloaded transformers. This problem was solved by changing transformers
locations where the transformers which are large and the load on them small were
changed with small highly loaded transformers. Then another transformers
connected in parallel with the left overloaded transformers this will need to buy new
transformers.
Appendix 8 shows the operation of transformer changing.
Table 3.3 shows the transformers which are needed to be bought:
Table 3.3
Number of transformers KVA
6 630
1 250
Table 3.4 shows the extra transformers left after solving the overloaded
transformers problem:
Table 3.4
Number of transformers KVA
1 100
1 50
19. Page 18
Table 3.5 summarizes the analysis results after changing transformers
Table 3.5
MW MVAR MVA % PF
Swing Bus(es):
17.388 6.867 18.695 93.01 lag
Total Demand:
17.388 6.867 18.695 93.01 lag
Total Motor Load:
9.394 4.163 10.275 91.43 lag
Total Static Load:
7.374 1.664 7.559 97.55 lag
Apparent Losses:
0.620 1.039
The voltages on the buses after changing the transformers are shown in Appendix 9.
3.5 New connection Point Study for the maximum load case
Tubas Electrical Distribution Company (TEDCO) is planning to add new connection
point for the company in Zawya area. This connection point is 5MVA rated.
Appendix 10 shows the voltages on the busses after adding the new connection
point. It is seen that the voltages after the new connection point were enhanced and
the losses decreased. And the power factor increased.
The following table shows the results summary after the new connection point
Table 3.6
MW MVAR MVA % PF
Swing Bus(es):
17.430 6.622 18.646 93.48 lag
Total Demand:
17.430 6.622 18.646 93.48 lag
Total Motor Load:
9.394 4.163 10.275 91.43 lag
Total Static Load:
7.599 1.712 7.790 97.55 lag
Apparent Losses:
0.437 0.747
20. Page 19
3.6 Improving the network with the new connection point
As before the improvement is done by tap changing and adding capacitor banks.
The changed taps and the added capacitor banks are shown in Appendix 11
The operating voltages are shown in the same appendix.
Now all buses are operating over 100% voltages. This will make the voltages reach to
the consumer with fewer losses.
The results of the improving are summarized in the following table
Table 3.7
MW MVAR MVA % PF
Swing Bus(es):
17.454 6.558 18.645 93.61 lag.
Total Demand:
17.454 6.558 18.645 93.61 lag
Total Motor Load:
9.394 4.163 10.275 91.43 lag
Total Static Load:
7.624 1.650 7.801 97.74 lag
Apparent Losses:
0.435 0.744
22. Page 21
4.1 Minimum Case Study
In the minimum load case the load is assumed to be half the maximum load.
The network analysis in this case shows the results in table 4.1
Table4.1
MW MVAR MVA % PF
Swing Bus(es):
8.381 3.480 9.075 92.36 lag
Total Demand:
8.381 3.480 9.075 92.36 lag
Total Motor Load:
4.699 2.082 5.140 91.43 lag
Total Static Load:
3.529 1.132 3.706 95.22 lag
Apparent Losses:
0.153 0.265
Appendix 12 shows the voltages on the buses for this case. It is noticed that these
voltages better than the voltages on the maximum load case.
Now taking the taps fixed as in the maximum load case the results shows that all the
buses have good voltage level and the power factor is in the range so no need to add
capacitor banks for this case, so the capacitor banks used in the network are all
regulated.
The following table shows the analysis summary with the taps changed
Table4.2
MW MVAR MVA % PF
Swing Bus(es):
8.720 3.614 9.439 92.38 lag
Total Demand:
8.720 3.614 9.439 92.38 lag
Total Motor Load:
4.699 2.082 5.140 91.43 lag
Total Static Load:
3.855 1.244 4.051 95.17 lag
Apparent Losses:
0.166 0.287
Voltages on buses after changing taps are shown in appendix 13
23. Page 22
4.2 Minimum Load Study After The Connection Point And Solving
Overloaded Transformers Problem
After solving overloaded transformers problem, as seen before some transformers
were changed and new transformers connected in parallel with some of overloaded
transformers. Also the new connection point is connected to the network.
The results for minimum load study in this case are shown in the following table4.3
Table 4.3
MW MVAR MVA % PF
Swing Bus(es):
8.738 3.541 9.428 92.68 lag
Total Demand:
8.738 3.541 9.428 92.68 lag
Total Motor Load:
4.699 2.082 5.140 91.43 lag
Total Static Load:
3.928 1.270 4.128 95.15 lag
Apparent Losses:
0.111 0.189
Appendix 14 Shows the voltages on the buses in the minimum case after changing
the transformers and connecting the new connection point.
It is noticed that the voltages and the power factor in this case are good, so no need
to add new capacitor banks to the network in this case, therefore all capacitor banks
connected are regulated. Also it can be seen that the losses decreased.
24. Page 23
The final results for the minimum load case are summarized in the following
table:
Table 4.4
MW MVAR MVA % PF
Swing Bus(es):
8.755 3.548 9.447 92.68 lag
Total Demand:
8.755 3.548 9.447 92.68 lag
Total Motor Load:
4.699 2.082 5.140 91.43 lag
Total Static Load:
3.945 1.276 4.146 95.15 lag
Apparent Losses:
0.111 0.190
The final voltages for the maximum case are shown in appendix 15
26. Page 25
Economical study
In this chapter economical study for the network will be done. This study is needed
to know whether it is reliable to connect the capacitor banks to the network or not.
Capacitor banks are reliable to be added to the network if their cost is acceptable
compared with the losses cost and power factor penalties, and their payback period
less than.
From this study the company can define its plans for the network.
In order to calculate the penalties on the low power factor, it is needed to know the
relation between low power factor and the penalty which is shown in the following
table
Table 4.1
PF Penalties
Over 92% No penalties
From 80% to 92% 1% of the total bill for every 1% decrease of PF
From 70% to 80% 1.25% of the total bill for every 1% decrease of PF
Less than 70% 1.5% of the total bill for every 1% decrease of PF
The amount of reactive power added to the network by capacitor banks is
The following parameters needed for the economical study:
P max= 16.755 MW
P min= 8.381 MW
Losses before improvement = 0.627 MW
Losses after improvement = 0.435 MW
PF before improvement = 91.33%
PF after improvement= 93.61%
The following calculations need to be applied to do the economical study:
27. Page 26
NIS
NIS
Cost of losses:
Losses before improvement = 627 × 0.748 = 468.996 KW
Energy = 468.996 × 8760 = 410.8404 × 104
KWH
Total cost=410.8404 × 104
× 0.45 = 1848782.232 NIS/YEAR
Losses after improvement = 435000 × 0.748 = 325.38 KW
Energy=325.38 × 8760 = 285.03288 × 104
KWH
Cost of losses=285.03288 × 104
× 0.45 = 128.2647 × 104
NIS/YEAR
= 566134 NIS/YEAR
Total capacitor = 905 KVAR
Cost per KVAR with control circuit = 15JD = 90NIS
Total cost of capacitors=905 × 90 = 81450 NIS
Total cost of transformers = 6 * 8200$ + 1 * 4000$
= 53200$ = 186200 NIS
Total investment cost = 81450 + 186200 = 267650 NIS
=3310072 + 566134 = 3876206 NIS
29. Page 28
6.1 Monitoring System
The second part of the project is to simulate monitoring system for the network. PIC
microcontroller is used to do the monitoring. Monitoring the network is important to the
electricity distributers, it make them make a better informed real time decisions and helps
them for future planning for the grid.
The monitoring system designed in this project concentrates on the supervision part of
monitoring systems.
The monitoring system designed for this project consists of the following parts:
Measurement devices.
The remote terminal unit (RTU).
Computer interface.
6.2 Current Measurement
It is important for the network supervisor to know the current in the network, because high
short circuit currents can cause severe damages in the system if they are not cured. The
supervisor can do the needed procedures for high currents before they cause the damage,
that if the protective devices in the network did not work well.
In this project the following circuit is used to measure the current:
Fig 6.1
30. Page 29
The current transformer (C.T) gives 4 volts at 10 amperes flowing in the primary side, then
the output voltage of the current transformer and according to Ohms law is divided on the
resistor connected in parallel with the transformer.
The signal then amplified by the op-amp (op amp amplification ratio is ) but this amplifier
inverse the signal so the buffer is used to get the signal in its actual shape. The buffer also
do the task of current isolation, to prevent relatively high current to damage the electronic
components in the next stage.
After this stage a rectifier circuit is used to take the peak of the voltage signal, to be in the
range of the microcontroller input. The rectifier circuit shown in the next figure
Fig 6.2
The low pass filter is to remove the high frequencies. The diode is to cut the negative half
wave of the voltage signal. The capacitor is to smooth the output DC signal.
6.3 Voltage Measurement
Voltage is another important parameter in the network, low voltages causes high currents. It
is needed to keep the voltages in a good range to keep the machines on the consumer side
work effectively and to reduce the losses in the network.
The way used to measure the voltage in this project is shown in the following circuit
31. Page 30
Fig 6.3
Here conventional transformer is used here instead of the potential transformer because it
is cheaper. The transformer ration is 220v:3.6v, as before the buffer is used for current
isolation and impedance matching.
As in the current measurement it is needed to rectify the voltage output signal to match the
controller output. The circuit is shown in figure
Fig 6.4
32. Page 31
6.4 Power Factor Measurement
The power factor is defined as cosine the angle between current and voltage signals. Here
the current and voltage signals will be transform to pulses, then they will be injected to PLL
(CD4046), the output of PLL will be the puls which its width represents the phase shift
between the signals.
The circuit to transform the signals from sign waves to a puls is shown below
Fig 6.5
Two distinct circuits will be needed to transform current and voltage signals to pulses. The
input of the circuit used for current signal is from circuit in figure 6.1. and the voltage signal
is from circuit in figure 6.3.
Fig 6.6
33. Page 32
The output of the PLL will be connected to B0 input of the microcontroller. Figure 6.6 shows
this operation.
6.1.1 shows the two signals A and B.
6.1.2 shows signal A pulses.
6.1.3 shows signal B pulses.
6.1.4 shows the output of PLL
Fig 6.7
A counter in the microcontroller will count the duration of the phase shift signal. The 50Hz
signal will have a duration of 20ms and 3600
so the angle of the phase shift will be found
according to the following relation (assume the duration of the phase shift puls is T and the
angle between the signals is φ).
Then the power factor will be cosine the angle.
34. Page 33
6.5 Frequency Measurement
In the frequency measurement the circuit in figure 6.3 in addition to other PLL will be
used. The output of the circuit will be sent to microcontroller and to the PLL, the
second input of the PLL will be a fixed signal with 20ms(i.e. 50Hz) from the
microcontroller will be applied to it.
The output of the PLL will be the difference between the fixed signal from the
microcontroller and the voltage pulses, the difference duration will be either added
or subtracted from the 50Hz. Addition and subtraction will be according to the
voltage puls duration, if it is more than 20ms it will be subtracted if less it will be
added. The duration of the voltage puls will be counted in the microcontroller.
Assume the duration of the PLL output is X and the voltage signal duration is Y
If Y>20ms then,
Else if Y<20ms then,
Fig 6.8.
35. Page 34
6.6 The Remote Terminal Unit (RTU)
The remote terminal unit control and send the data collected from the network
process them and send them to the supervision computer. The microcontroller used
in the RTU is PIC16F877A. PIC microcontroller is used because it is simple, available
all the time, and cheap.
The basic circuit for this microcontroller is shown in fig 6.9 below.
Fig 6.9
The data from the measurement devices is not the actual values for the network
parameters, calibration is done for the measurement devices and the values of the
measurement devices is multiplied by the factors in the microcontroller to return to
their actual value, then these values will be send to the computer.
To connect the microcontroller to the computer MAX232 is used to send the data
serially to the computer through RS232. As in the circuit in figure 6.10.
36. Page 35
Fig 6.10
In the computer an application programmed using C# programming language to read
the data from the serial port and preview them.
Pictures for the project in appendix A16
74. Page 73
Appendix 10
Voltages on buses after the new connection point
Bus Vrated Operating (%)
Bus65 0.4 98.484
Bus68 0.4 99.519
Bus69 0.4 98.241
Bus70 0.4 97.853
101. Page 100
References:
http://penra.gov.ps/
Elements of Power System Analysis by William D. Stevenson
Electric Power Generation, Transmission and Distribution, 2nd
edition by
Leonard L. Grigsby.
Power Systems, 2nd
edition by Leonard L. Grigsby.
Supervisory control and data acquisition systems for command, control,
communications, computer, By Headquarters Department of The Army
Washington, DC, 21 January 2006.
What are amps, watts, volts and ohms?, HowStuffWorks.com, 31 October
2000. Last accessed: 27 June 2010
http://www.opamp-electronics.com/tutorials/energy_losses_2_09_09.htm
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