CAPÍTULO 3: DIAGNOSTICO, ANALISIS Y DISCUSION DE RESULTADOS
3.3 Los cursos de formación
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At the current exchange rate of about NGN160/USD, the total cost Ct which amount to
USD 276,171.5 is equivalent in local currency to N44,187,440.00k
Hence the average energy produced by solar PV per sunshine day is given by ET = 9.0[(200 x 50) + (100 x 75) + (100 x 100) + (500 x 25) + (100 x 60)]
9 x 46,000 414kWhr
Thus the expected annual energy production is obtained as follows ET = 365 x PT x Td av. ……… (3.1)
PT = ∑ Pn𝑛1
= 414kWhr x 365 days = 151,110kWhr
= 151.1GWhr/year
Table 3.5: Bill of Quantity for the Installation of 48.8kW Solar Photovoltaic Array in Port Harcourt, Rivers State
S/n Description Unit Qty Rate Amount in (usd)
1 Solar Power W 48.3kW 4.18 201,894
2 Inverter W 48.5KW 0.715 34,677.5
3 Solar plates supporting structures
Lot 84 100 8,400
4 Cabling and connections Lot lot 7,500 7,500
5 Cost of land Lot Lot 25,000 25,000
6 Cost of cutting trees and bush clearance
Lot lot 2,300 2,300
7 Logistics Lot Lot 3,200 3,200
8 License and Registration Lot 1 1,500 1,500
9 Skilled labor Lot Lot 15,000 15,000
10 Total 299,471.5 USD
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At the current exchange rate of about NGN160/USD, the total cost (Ct) which amount to
USD 299,471.5 is equivalent in local currency to N47, 915,440.00k
Hence the average energy produced by solar PV per sunshine day is given by ET = 5.0[(200 x 50) + (100 x 75) + (100 x 100) + (500 x 25) + (100 x 60)]
5 x 46,000 230kWhr
Thus the expected annual energy production is obtained as follows ET = 365 x PT x Td av. ………( 3.2)
PT = ∑ Pn𝑛1
= 230kWhr x 365 days = 83.95GWhr/year
3.2.2 Simulation Result in Case of Three Phase Fault Connection
In this section some simulation results are presented in order to check the model active and reactive power to the grid. A pure three phase fault has been performed in the medium voltage grid bus – bar. The short circuit power of the external grid which is – connected at this point is 45mva.
In steady state, the PV park is injecting 1.34MW to the grid and observing 0.23MVar from the grid, which gives a cos Ø ≥ 0.881 this absorption of reactive power is due to the transmission line. The voltages in the steady state are 0.98 P.U in the medium voltage photovoltaic park – bus of each group.
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A pure three – phase short circuit is simulated in the medium voltage bus – bar the short circuit is created in 0.5 sec. the MV PV parks voltage in P.U and the injected reactive power to the grid in PU is S = 1.0MVA.
In order to analyze the behavior of the grid in steady state when the PV power plant is connected, the power – voltage curves are obtained i.e. two types of power – voltages are obtained:
(1) When the injected power of the PV plant varies (2) When the short circuit power of the grid varies.
Work sheet for determining required number of panels.
Total capacity of the plant 1MWp Average sun hrs per day 5 hrs
Total watt hour per day 5x1000x1000 Wh/day Maximum solar insulation 6.18kw – h/m2/day At the site
5 ×100 ×1000 6.18 = Divide total watt hours / day 809061.49 By solar insulation
Multiply this figure by 1.2 809061.49 x 1.2 = 970873.79 (to cover system inefficiency)
Therefore the total no. of panels required 9700873.79 300
Where 300 = 300 Wp (solar panels used) 3,236 Solar Panels
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For improve efficiency and good utilization of inverters and other components, 3,236 number of solar panels should be considered.
3.2.3 Solar PV Arrangement and Overall System Rating Table 3.6: Rating of Solar Panel
Watt p (w) 300 Wp
DC Voltage Vmp (v) DC current Imp (A)
Open circuit voltage (Voc) Short circuit current (Isc)
36.72 V 8.17 A 45.50 V 8.65 Amps
Setup of Panels as per Requirement
By calculation and the demand of the plant, the total number of solar PV panels to be used = 3,236
3236 panels are considered to generate the required energy of I.0MW.
3.2.4 Configuration Details
3,236 panels are divided into 4 groups each group containing 810 solar panels.
In each group 810 panels are further divided in to four (4) strings. Each string contains 15 solar photovoltaic panels.
44 Table 3.7: Electrical Calculations
System Voltage/Current Output Estimated Output
Output voltage of each string Out put current of each string Out put voltage of each group Output current of each group
36.72 x 15 = 550.8 Vd.c 8.17 A d.c
550.8V d.c
8.17 x 54 = 441.18A d.c
In each string the solar panels are connected in series in order to increase the system voltage. While in each group the 54 string are connected in parallel in order to raise the system output current.
Table 3.8: DC Output Power Calculations
String/Group output Estimated power
Output power of each string Output power of each group Output power of 4 groups
550.8 x 8.17 = 4.5kW 4.5 x 54 = 243 KW 243 x 4 = 972KW
45 3.2.5 Inverter Specifications Details Type of inverter: Central inverter considered.
Recommended Specifications
Table 3.8: Inverter Details. Input DC
Inverter Technical Specification Input Power D.C
Maximum power
DC voltage range mpp (UDC) Max DC voltage Umax DC Max DC current I max DC Voltage ripple
Number of protected DC inputs (parallel)
300kWp 450-750V 900 V (1000 V) 600 A
< 3%
2 (+1-)/8
Output AC
Inverter Technical Specification Output Power A.C
Nominal AC output power (PN AC) Nominal AC current (IN AC)
Nominal output voltage UN AC Output frequency
Harmonic distortion current Power factor compensation Cos Distribution network type
250kw 485 A 300 V 50 Hz
< 3%
Yes TN only
To meet these criteria, central inverter manufactured by ABB is considered.
(PVS 800 – 57 – 0250 kW – A inverter)
Total of 4 inverters of PVS 800 – 57 – 0250kw – A type required to generate 1MW power
46 3.2.6 D.C Side Protections
Power system protection is an integral part of PV system. Protective devices are use to provide adequate protection against internal and external faults that can damage to equipments. The main protection and protective gears are as follows.
1. Fuses
a. For string protection
b. Fuses for array inverter input protection 2. Fuse Holders
a. For string protection b. Panel mount fuse holder c. In line fuse holders
d. Array inverter input protection e. Dead front fuse covers.
3. Surge protection devices 4. DC Switch
a. Load break and disconnect switches b. High power switches
5. Cooling Devices a. Air (Natural)
6. Wire management solutions
a. Finger safe power distribution block b. Finger safe comb wiring bar
7. Ground fault protection
a. Earth leakage circuit breaker
47 3.2.7 Solar SCADA System
Data acquisition system for a solar plant is very important because it is useful to monitor the overall system condition, including input/output condition, temperature, and solar insolation, voltage/current fluctuation, output power variation, surge effects and the load dispatch. Solar system scada is used to generate useful information that may be applied to upgrade the system in the future. The scada system can be navigated to access vital information regarding system operation and control of the PV power plant.
Recent development has made it possible to carryout monitoring and metering of the energy produce/consumed through application of scada system. However for a PV system located in remote area for the purpose of rural electrification, a mini solar scada system is sufficient to record events and supervise the daily meteorological data for future research and development.
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CHAPTER FOUR 4.0 CONCLUSIONS AND RECOMMENDATIONS