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Research Article Impact Factor: 4.226 ISSN: 2319-507X Alzyoud AR, IJPRET, 2014; Volume 3 (2): 107-130 IJPRET

Available Online at www.ijpret.com

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INTERNATIONAL JOURNAL OF PURE AND APPLIED RESEARCH IN ENGINEERING AND

TECHNOLOGY A PATH FOR HORIZING YOUR INNOVATIVE WORK

INTEGRATION OF SOLAR FARMS INTO JORDANIAN ELECTRICAL POWER SYSTEM

ABDALLAH R. ALZYOUD

Electrical Engineering Department, Faculty Of Engineering Technology ,Al-Balqa’ Applied

University, Amman 11134,Jordan

Accepted Date: 12/08/2014; Published Date: 01/10/2014

\

Abstract: This research introduces a study of utilizing solar energy farm integrated with the national grid according to an intensive data available of solar energy in Jordan. This study discusses the effects and the ability of installing solar farms to the Jordanian national grid considering different cases and, thus the power system studies i.e. (power losses, voltage profile) for connection points of solar farms to 33kV medium voltage networks. Calculations are performed and models are built using real data obtained from the Jordanian power system. The most suitable method of connection of the solar farm is recommended related to national power network.

Keywords: Renewable energy, Solar system, Distribution network, Voltage profile, Power losses.

Corresponding Author: MR. ABDALLAH R.ALZYOUD

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Alzyoud AR, IJPRET, 2014; Volume 3 (2): 107-130

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INTRODUCTION

Photovoltaic (PV) energy is one of the cleanest forms of renewable energy. The recent

observance in the climatic changes has paved the way for exploiting more green energy

resources like solar. Though the technology seems to be expensive, it has found itself a new

dimension and has got a very good reception in the society especially with the introduction of

programs like Feed in Tariff and the incentives provided by them [1-3]

Jordan is a very rich country in renewable resources especially solar, the average peak sun

hours are estimated to be around 5.8 hours per day which is amongst the highest in the world,

furthermore the temperatures are not very high which is beneficial for the panels power output

efficiency[ 4].

Jordan is a non-oil-producing country and imports 96% of the energy used. As a consequence,

energy imports accounts for roughly 22% of the GDP. The population’s growth rate is high;

about 2.3% per year. This causes the demand on energy sources, mainly oil products to increase

rapidly. The energy crisis in Jordan drives us to move toward alternative energy, especially solar

energy. Implementation of renewable energy resources such as solar energy, will lead to

economic, social and environmental benefits [4, 6].

The Jordanian market is currently witnessing a huge increase in photovoltaic energy projects

demand and that's due to the increase in electricity bill costs and due to the introduction of the

renewable energy law which has included the net metering application [5].

Jordan lies within the solar belt of the world with high average solar radiation. Decentralized

photovoltaic units in rural and remote villages are currently used for lighting, water pumping

and other social services (1000kW of peak capacity). In addition, about 15% of all households in

Jordan are equipped with solar water heating systems in May 2012, also a 280 kilo watt solar

electricity system was inaugurated to be used at El Hassan Science City.

As per the Energy Master Plan, 30 percent of all households are expected to be equipped with

solar water heating system by the year 2020. The government is hoping to construct the first

Concentrated Solar Power (CSP) demonstration project in the short to medium term and is

considering Aqaba and the south-eastern region for this purpose. It is also planning to have

solar desalination plant. According to the national strategy the planned installed capacity will

amount to 300MW – 600MW (CSP, PV and hybrid power plants) by 2020.

Interconnection of photovoltaic (PV) power system to the grid is considered in this paper

.Detailed models of the PV array, power converter and connected grid is used in the simulation.



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In this research the voltage at busses under the simulated solar PV is determined, also the real

and reactive power flow are studied.

This research presents two scenarios with identical PV systems but with different connection

points to the distribution network, the first to 33kV sending bus and the second to 33kV

receiving bus. The different scenarios are simulated using energy technology assistance

program (ETAP), and then the effects of integration the solar farms into the grid are analyzed

and evaluated.

2. SOLAR RESOURCE POTENTIALS IN JORDAN

Jordan has a great solar power potential (Among the best in the world),the annual-average

daily solar radiation is around 5.5-6.0 kWh/ m² ,the yearly hours of sunshine are approximately

3300 hours ,relatively moderate temperatures and relatively low dust and low humidity levels.

Because of this great solar power potential it must pay attention to this renewable source and

use it as a source for generating electric power to reduce Jordan's energy crisis rather than

relying on neighboring countries and increase costs to the Jordan budget [6-7].

Jordan has launched a comprehensive strategy for the development of the energy sector and

increases the reliability of renewable energy. The strategy has studied all alternatives and

economic options available to meet the demand of energy in all its forms. It has suggested

specific mechanisms to ensure the security of energy supply, including the needed

infrastructure projects. The estimated investment cost for the infrastructure projects included

in the strategy would amount to 14 -18 billion US dollars for the period (2007-2020) .The

proportion of reliance on renewable energy sources increase from 2% in 2010 to 10% for the

year 2020. Figure 1 illustrates energy mix of current and projected.

Fig.1. Energy Mix of Current and Projected[7]



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Jordan lies between latitudes 29° and 34° N, and longitudes 35° and 40° E (a small area lies west

of 35°). It consists of an arid plateau in the east, irrigated by oasis and seasonal water streams,

with highland area in the west of arable land and Mediterranean evergreen forestry; it extends

over a surface of 88788 km2.

Jordan has a promising potential of power generation from solar energy, which basically

constitute a national resource waiting to be invested to the full extent.

Jordan has an excellent level of solar irradiance as shown in the solar irradiance distribution

atlas shown in figure 2.

Fig.2.Solar radiation map of Jordan[23]

The selected location for the project is Sabha area which is located in the north-east with

coordinates (32.32965°N, 36.50098°E) and characterized by a rise from sea level up to

837m,the presence of water pumping loads, ambient temperature and low cost area which

decreases the operating cost of the project.

Figure 3 shows the location of the project in Jordan, while Figure 4 shows the exact project

location [11].

http://en.wikipedia.org/wiki/29th_parallel_north

http://en.wikipedia.org/wiki/34th_parallel_north

http://en.wikipedia.org/wiki/35th_meridian_east

http://en.wikipedia.org/wiki/40th_meridian_east



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Fig.3. General Project Location

Fig.4. Exact Project Location

3. SYSTEM CONFIGURATION MODEL

The system configuration model was built using Hybrid Optimization for Electric Renewable

(HOMER) and it’s shown in Figure 5.

Fig.5. System Model Configuration



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The system is composed of two main busses: a DC bus and an AC bus. The PV panels are

connected to the DC bus logically because the output of the PV panels is DC; this power is then

converted to AC using an inverter and connected to the AC bus to which the electrical load is

connected.

3.1 Solar Data for the selected site

Solar irradiance data for Sabha location were obtained from the (HOMER).

The data obtained is shown in table 1 and illustrated in figure 6, the average solar radiation is

about 5.480 kWh/m².day which is a very high value and suitable for electrical power

generation.

Table (1): The average daily solar radiation incident in one square meter area

(kwh/m²/d) for Sabha

Fig.6. The average daily solar radiation incident on one square meter area (kwh/m²/d) for Sabha



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3.2 Solar Radiation Profile

The latitude specifies the location on the Earth's surface. It is an important variable in solar

calculations. HOMER uses it to calculate radiation values from clearness indices, and vice versa.

It also uses the latitude to calculate the radiation incident on a tilted surface. All curves shown

in figures (7,8,9).

3.2.1 Hourly Radiation Curve

In Figure 7 it can be observed that the maximum solar radiation would be at midday in the

middle of June.

Fig.7. Hourly solar radiation curve.

3.2.2 Scaled Data Monthly Averages

The maximum solar radiation would be in June and July.

Fig.8. Scaled data monthly averages.



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3.2.3 Scaled Data Daily Profile

Fig.9. Scaled data daily profile.

3.3 Load profile and characteristics

A load profile is a graph of the variation in the electrical load versus time. The load data for

Sabha used in this paper were obtained from the National Electric Power Company (NEPCO),

the data is given in 10 minutes intervals for every day of the year 2011. The data were analyzed

and summarized to an average day for each month which resulted in 12 average days as shown

in Table 2.

Table (2): Monthly average load MW per hour.(National Electric Power Company (NEPCO)).

http://en.wikipedia.org/wiki/Electrical_load



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The data was fed to (HOMER) and synthesized to 8760 hours, the main characteristics of the

load demand are shown in table 3

Table (3): Sabha Load profile characteristics.

Average (MWh/d) 376,8

Average (MW) 15,7

Peak (MW) 43,4

Load factor .361

3.4 Load curves

A load curve is a chart used by engineers and power producers to show how much electricity

customers utilize during a given period of time. When looking at the graph, time usually is

placed on the horizontal axis, and load is placed on the vertical axis. This data can be used to

predict power trends, which allows an area to build and connect sufficient power generators for

peak demand periods. Types of power generators vary depending on the resources in a

geographic area. Load curves can be calculated in different ways depending on the needs of the

electrical suppliers.

Daily, monthly and yearly load curves are used by power stations to determine the amount of

generators needed. Daily load curves look at a 24-hour period of time to find the load

requirements every half-hour or hour. A monthly curve records load changes during a one

month time period versus the number of days recorded, and a yearly load curve establishes the

variations in power requirements throughout one year based upon the monthly load variations.

The highest point on a load curve is the maximum demand at a given point in time. The area

under a curve is the amount of units that were generated during that period of time.

http://www.wisegeek.com/what-are-suppliers.htm



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3.4.1 Monthly average load curve

Fig.10. monthly average load curve for Sabha

3.4.2 Daily Average load curve

Fig.11. The average daily demand for months of year 2011 in Sabha



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3.5 PV system Description

The Philadelphia solar module M72-300 PV was chosen for modeling, since it is well suited for

traditional applications of photovoltaic systems [8].

The M72-300 module provides 300 watts of nominal maximum power, and has 72 series

connected Mono-Crystalline cells. The key specifications are shown in table 4 below.

Table (4): Philadelphia M-72 Panel characteristics (Philadelphia M-72 PV Panel data sheet).

UNIT VALUES The Philadelphia solar M72-

300 PV DATA

W 300 Nominal power [Pnom]

V 36.58 Voltage at Nominal Power

[Vmpp]

A 8.21 Current at Nominal Power[I

mpp]

V 45.36 Open-circuit Voltage[Voc]

A 8.78 Short-circuit Current[Isc]

mV/cell/C° -2.11 Voltage Temperature

Coefficient

mA/cell/C° 4.62 Current Temperature

Coefficient

% 15.4 Module Efficiency

Mm 1965 Length

Mm 990 Width

m² 1.95 Area



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This PV solar system consists of 32 PV arrays ,each array contains 1667 solar panels, with

output 300 watt for each panel connecting 27 solar panels in series which is called strings to get

987.66 V and 112 in parallel to get 907 kW DC and current with 918.53 A. These data are used

in the SMA central inverter with 1100 KVA and unity power factor output .Table 5 shows the

technical data for the inverter.

Table (5): Technical data for SUNNY CENTRA 1000MV-20

UNIT VALUES The SMA central inverter data

KW 1120 Max. DC power

V 1000 Max. input voltage

V 480 Rated input voltage

A 2500 Max. input current

KVA 1100 Output rated power

V 2000 Nominal AC voltage

Hz 50 Ac power frequency

A 31.8 Max. output current

% 98 Max. efficiency

The inverters connected to 20kV bus bar which is suitable to their output voltage.

The PV- power plant with output 15.7 MVA at unity power factor is connected to the national

power grid through 25 MVA transformer to step up its voltage to 33 kV substation.

3.6 Distribution Network Description

The distribution network of Sabha is fed from the power grid of 132kV through two 40 MVA

step down transformers (132 /33 kV) to supply the town's load.

4. SIMULATION USING ETAP

Energy technology assistance program (ETAP) is used to simulate the PV solar system

integrated with the grid [9]. ETAP is the most comprehensive analysis platform for the design,



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simulation, operation, and automation of generation, distribution, and industrial power

systems. In this paper three cases are studied and analyzed.

4.1 Case Studies

4.1.1 Case I: Electrical Distribution Network without PV Solar System

Case I consists of the Sabha electric distribution network which is fed from the National

Electrical Power Company (NEPCO) [10]. Figure 12 shows the single line diagram of electric

distribution network

Fig.12. Single line diagram of sabha distribution network.

The load flow of the distribution network is shown in Figure 13:



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Fig.13. Load flow of the distribution network of Sabha

4.1.2 Case II: PV Solar System is Connected to 33kV Sending Bus Bar at Average Load.

Case II consists of the distribution system with the solar plant 33 kV bus bar near the grid ,

Figure 14 shows the single line diagram of this case:



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Figure (14): ETAP single line diagram for case II.

The load flow for the transformers and distribution lines is shown in Figure 15.



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Fig.15. ETAP load flow diagram for case II

4.1.3 Case III: PV Solar System is Connected to 33kV Receiving Bus Bar at Average Load.

Case III consists of the distribution system with solar plant connected to the receiving side of 33

kV bus bar and the Figure 16 shows the single line diagram of this case.



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Fig.16. ETAP single line diagram for case III.



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Figure 17 shows the PV Arrays connected to 33kV receiving bus bar at average load with load

flow

Fig.17. ETAP load flow diagram for case III.



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5. RESULTS AND ANALYSIS

5.1 Impact of PV system on Power losses values

According to the analysis of simulation results, the total power losses through the branches are

shown in table 5 for the three cases. In case of connecting solar plant to the 33 kV receiving bus

bar the power losses are decreased clearly compared to the normal system's losses , and when

connecting the solar plant on 33 kV sending bus bar , the total losses decrease slightly with

comparison to the normal system's losses.

Table (5): Power losses of the distribution network for different cases

With solar plant at

receiving end 33kV

With solar plant at

sending end33kV

Without solar plant Branch CKT

kVAr kW kVAr kW kVAr kW ID

678.3 24.8 679.4 24.9 1.3508 49.5 T3

678.3 24.8 679.4 24.9 1.3508 49.5 T5

691.7 29.2 667.2 28.2 - - T4

109 54.5 322 161 321.4 160.7 Line1

109 54.5 322 161 321.4 160.7 Line5

104.7 52.3 102.6 51.3 102.4 51.2 Line6

104.7 52.3 102.6 51.3 102.4 51.2 Line8

7 1.3 2.6 1.3 2.6 1.3 Line9

1791 264.5 2210.6 475.7 852.902 524.1 Total

losses

except PV

plant



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5.2 Impact of PV system on voltage Variation

In this paper, a load flow analysis of the distribution network is performed for various cases

(3cases). Table 6 shows bus voltages and voltage drop for the distribution network elements of

the three differentcases.

Table (6): Bus voltages and voltage drop of the distribution network elements for different

cases

With solar plant at

receiving end 33kV

With solar plant at

sending end33kV

Without solar plant Branch

CKT

Voltage

Drop,%

Bus

Voltage,%

Voltage

Drop,%

Bus

Voltage,%

Voltage

Drop,%

Bus

Voltage ,%

ID

3.552 96.448 3.576 96.424 3.661 96.339 T3

3.552 96.448 3.576 96.424 3.661 96.339 T5

0.118 94.818 0.208 96.424 - - T4

1.748 94.7 2.661 93.763 2.66 93.678 Line1

1.748 94.7 2.661 93.763 2.66 93.678 Line5

1.067 93.633 1.33 92.433 1.05 92.624 Line6

0.055 94.645 0.05 93.763 0.05 93.627 Line8

1.067 93.633 1.33 92.433 1.05 92.624 Line9

5.3 Impact of the installation capacity of PV system on the power losses and voltage profile.

According to the load flow analysis the power losses and voltage profile are determined and

summarized in table 7



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Table (7): Voltage profile and total power losses for different installation capacities of the PV

system

Figure 18 illustrates the voltage profile and figure 19 illustrates the power losses for a PV

system with various installation capacities.

Fig.18. voltage profile with various PV installation capacities.

PV (MW) V1 (KV) V2 (KV) V3 (KV) V4 (KV) V5 (KV) V6 (KV) Total

Losses

(kw)

0.0 132 31.792 30.914 30.566 30.897 30.566 524.1

1.781 132 31.82 30.961 30.613 30.944 30.613 475.9

3.577 132 31.81 31.006 30.657 30.988 30.57 432.5

7.155 132 31.823 31.088 30.738 31.077 30.733 359.1

10.732 132 31.829 31.16 30.809 31.142 30.809 307.5

14.31 132 31.83 31.223 30.871 31.205 30.871 274.1

16.099 132 31.828 31.251 30.899 31.233 30.899 264.5



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Fig.19. voltage profile with various PV installation capacities.

6. CONCLUSION

This paper discusses one of the most modern ways of electricity production, using renewable

energy sources in distributed generation systems.

The system was designed and simulated using two programs, HOMER and ETAP.

After selecting the suitable site for PV solar plant presented by Sabha town, Homer program

was used in designing the solar system using the parameters of the well chosen various

elements, such as the PV panel models, to get the values of an average load and peak load. A

PV plant of (53333) panels were needed in order to cover the demand of the loads connected

to the system.

Implementation of PV solar system reduces the power losses and hence can be benefited from

all of the systems produced energy. It also improves the voltage profile on the distribution

network elements especially when the PV solar system is connected to the grid near the center

of electrical loads.

Acknowledgement: "This work has been carried out during sabbatical leave granted to the

author (Abdallah Alzyoud) from Al-Balqa' Applied University (BAU) during the academic year

2013/2014



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