Comparison of Experimental and Theoretical Output Power of Grid Connected Photovoltaic System in Super Mega Factory Wint Wint Kyaw, Than Zaw Htwe, Zeya 00
Kyaw Kyaw Htet Department of Electrical Power Engineering Yangon Technological University Yangon , Myanmar
[email protected]
Abstract-In accordance with radiation data of Myanmar, solar energy is one of the best options for electrical energy generation techniques. PV solar panels or array are electrically connected or "tied" to the local mains electricity grid which feeds electrical energy back into the grid is known as a "grid-tied", or "on-grid" solar system (6). In this paper, the performance of grid connected PV system that is installed in Super Mega Factory is presented. The output results are collected and analyzed. To get
Department of Electrical Power Engineering Department of Engineering Physics Yangon Technological University Yangon, Myanmar
[email protected] wintwintkyaw.
[email protected],
[email protected]
power of photovoltaic modules may vary according to different weather conditions and the mounting position of the panel and other factors [1]. So as to vary the output power, this system is needed to monitor the output power. If there were widely difference between the actual power and rated power, the weak point might be fmd out to get the suitable power.
the maximum output power makes the correction of collector
A. Grid Connected Without Battery Back up System
angle and place suitable panel position.
Solar PV modules geneate DC electricity.The grid-tied solar inverter converts the DC electricity generated by solar PV modules into AC and feeds into the grid. The systems without battery up are more common and consist of two main components solar PV array and grid tied inverter or power conditioner. The controller to extract maximum DC power from PV array is in-built in a inverter. This type of system is easy to install, efficient and cost effective, it has no means of supplying AC power when the grid is not available. Removing the battery subsystem not only represents a considerable cost and size reduction of the whole system but also increases its reliability while a PV cell lasts more than 20 years, a battery operates for almost 5years and needs periodic maintenance[2] [5].
Keywords-Grid connected PV system, power conditioner PV array, meteringv
I.
INTRODUCTION
Myanmar has experienced a nwnber of power crises, mainly due to the heavy reliance on hydroelectric power Renewable sources are sources of energy which can support easily the place where electricity cannot supply and sent to the grid line in the daytime to be stable the main grid. In 2015,Thiland has more solar power capacity than all of Southeast Asia combined. Germany is the world's largest producer of solar power with an overall installed capacity of 38.2 GW. Solar power in Myanmar has the potential to generate 51,973.8 TWh/year, with an average of over 5 sun hours per day [7]. In rural areas, solar energy-stand alone system has been utilized for domestic use in lighting, pumping and other factors .Small scale grid connected PV system is installed in some factories. The main advantage of a grid connected PV system is its simplicity, relatively low operating and maintenance costs as well as reduces electricity bills. In this paper, the grid connected photovoltaic system without battery back-up is described. The capacity bank is 4kw. Eighteen numbers of PV modules, metering panel and conditioner are used in this system. This system supports the electricity to factory not all the capacity their needs. The output
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B. Performance of Grid Connected P V System in Factory
In super mega factory, on-grid (4kW) photovoltaic without battery up system is installed. There are sixteen numbers of poly crystalline PV modules (245W), 4kw delta power conditioner and metering panel in this system. Eight modules are connected in series to form a string. The power output of one module is 245W.For a one string, output power extracted 1960W Two strings are connected in parallel so output power is 3920W which is close to 4kW.Output voltage of a string is 296V. The output voltage and current of pv array first passes through the metering panel and also the incoming grid line also does and input voltage and current of grid line are also
measured. After passing through the metering panel, the output of pv and incoming grid line combines in power conditioner, within the grid input voltage (l80V�250V) and the input DC voltage (80V�450V) the conditioner synchronize the output parameters. Time taken for synchronizing is 90s to match the voltage and current of the grid line and pv output. After condition, the conditioner sent the voltage and current to the load. The power system of factory is three phase for heavy machinery such as punching and drilling and single phase for lightning and others electrical appliances like lightning.
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Fig. l.Solar Panel Voltage on Different Conditions
0.6 0.4 0.2 o
Fig. 3. Output Power on the Different Condition
Fig. 2 shows that the radiation of the sun increases, the output current also increases. There are two lines in this figure, the red line, output current from sunny day and the blue ones is for cloudy day. Figure 2 mentions that at first output current for sunny day, the starting current is 5A at 8 am and then the current has been dramatically raised to 7A at 1:30 pm. It reaches a peak 8.5A at 2pm.And then there is a steady decrease to the lowest point nearly lA.In contrast, being the cloudy day, the radiation of the sun touching to earth may vary cause of mass cloud. The current rises from 5A to 6.5A within 2 hours, and then falls slightly. However there is a rise again to 7A, but a rapid drop has been occurred to 4A. Again raise and a sharp increase at 1:30 pm 8A.And the rest of the time gradually falls to its lowest ampere. Fig.3 represents the output power of conditioner. As the output current and voltage get less on cloudy day, the output power also decrease too. Firstly the graph says for cloudy condition, the blue line, at 8 am, the output power starts 1.2kW, and increase till 10:30 am, after that slightly decline to 1A.And then it fluctuates, at 1:30 pm, the power sharply increases 1.89Aand suddenly drops 1.2A.Furthurmore, the rest of the day, the output power gradually declines. On cloudy day, the obvious answer is that there has a wide fluctuation, and the trend is downward. On sunny day, the red line, the power
begins one kilowatt and keeps on increasing 1.5 kW until 1:15pm, after that it reaches a peak power nearly 2 kW. Starting at 2:45pm, the output power has been declined gradually. Finally, the power goes down 0.3kW. As experimental results, even in the sunny day, output power is obtained maximum nearly 2kW but the installed capacity is 4kW for factory. Therefore, the obvious answer is that there are doubled different between the experimental and rated power. A.
Correction o/the existing output power using theoritical wcry
Being the experimental and rated power output different from 2kW,so the mounting position, collector tilted angle and the environmental effect fIrstly have to be checked. As a result of examining the physical characteristic of the system, fIrst one, the place where the panels mounted is dusty and close to river so that the air gets salty, it can affects the solar panels surface. Another one concerns with wrong mounting position and collector tilted angle. The panels faces to north instead of facing south position, furthermore the collector tilted angle is 23degree that is much. In practice, the solar panels should therefore be positioned at an angle to the horizontal plane (tilted). Near the equator the solar panel should be placed slightly tilted (almost horizontal) to allow rain to wash away the dust. Panels are often set to latitude tilt, an angle equal to the latitude, but performance can be improved by adjusting the angle for summer and winter. Suitable degree is 17 or 18 degree at least 20degree cause latitude of Myanmar is 16.8 degree. Using the following theoretical equations, the output power is made correction. L1 = 23.45
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