University of South Wales Master of Sciences Thesis
Standalone hybrid generation system for the remote area of Thar, Pakistan
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- 2.2.4. PV-array Implementation
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Standalone hybrid generation system for the remote area of Thar, Pakistan system voltage is chosen to be 24V if daily energy demand is greater than 1KWh and 12V if it is less than 1KWh. The system sizing depends on the estimation of the peak-load demands of loads. The total estimated power demand can be found [9, 11]: 2.4 Where Pest = total estimated peak-load power Pli = Peak power of single load, for loads I = 1, 2, 3…n. The DCC12 of the PV-arrays can then be determined at this point as [9]: 2.5 2.2.4. PV-array Implementation The most important factors, which have to be considered with the implementation of the PV modules, are [9, 11]: • Daily energy demand • Solar insolation at the geographical location specified • Methods of mounting the modules When talking about mounting methods of PV-modules, either fixed mounting or mounting on tracker techniques can be used with the latter yielding about 20% more output than the former option [9]. However, it requires more skilled maintenance. Taking the less familiarity of rural community toward this into consideration, fixed mounting techniques have been advisably used in the rural electrification with HPSs. Fig. 2.5 series and parallel connection of the PV-modules. The number of series connected PV-modules can be calculated as follows [12]: 2.5 Where, Ns = the number of series connected PV-module (rounded up to a whole number) Vsys = nominal system voltage Vmod = nominal module voltage. Standalone hybrid generation system for the remote area of Thar, Pakistan The number of parallel panels can be determined as [9, 12]: 2.6 Where, Np = number of parallel connected modules (rounded up to a whole number). LDA = Average daily load (A). A:L = average photovoltaic Ah available-to-average daily load Ah ratio. SL = system loss. Imp = module current at maximum power (A). DSH = the daily sun hours. Isc, PV module = Short circuit current per chosen PV module The average daily PV-to-load Ah ratio can be determined from [12] 2.7 Where DRT is the daily running time of the system and typical A:L values are 1.1-1.2 for non-critical loads and 1.3-1.4 or higher for critical loads, and the month with lowest A:L ratio has to be taken when designing a PV-array system[12]. The total number of PV-modules forming PV-array is, therefore [13]: 2.8 tải về 6.62 Mb. Chia sẻ với bạn bè của bạn:
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