| Low power generation efficiency is one of the main obstacles to apply PV modules by large scale, therefore, studying the influence factors of is of great significance. The ash deposition, the occlusion and the assemble angle can affect the power generation efficiency of PV modules with different degrees. Under the condition of the same radiation, the more gross radiation quantity received by PV modules, the better the electricity generating performs. The ash deposition and the occlusion reduce the amount of solar radiation of the photo-voltaic cells by the form of affecting the transmittance of, and the assemble angle does by the form of affecting the amount of radiation absorbed by PV panels.This article has independently developed a kind of automatic dedusting system of PV modules, which has the advantage of simple structure, low installation cost, reliable operation, without the use of water in the ash deposition, continuous and effective dedusting. The system has applied to three kinds of occasions, including supplying power separately by the photo-voltaic conversion cell under arctic conditions, having various experimental tests of the assemble angles by the photo-voltaic module cells and a large area of the photo-voltaic power system. Take the automatic dedusting system as research means, the dynamic occlusion in the operation process has been simulated and the influence law of the output parameter for PV modules has been researched; the effect of dedusting has been analyzed under different amounts of the ash deposition; the effect of dedusting changing with the amount of the ash deposition has been summarized, and the opening time and the running period have been determined. The experimental PV modules are placed in outdoor open ground at a 45 degree angle for 3, 7, 20 days and the amounts of the ash deposition are 0.1274, 0.2933, 0.8493 g/m2 separately. The correction coefficient of PV modules involved in the experiments is 0.9943. The results show that, when the system is in the horizontal and vertical cycle, the cleaning brush makes the output parameters of the photo-voltaic modules, including the output power, the electric current, and the voltage, change according to the V-law as it crosses a pack of battery. Compared with the process of down-link, the output parameters of PV modules in the process of up-link fluctuate more largely. When the dynamic occlusion area is increased by 1.6150%, the power output of PV modules will lead to decline in the low value of about 40%; when the automatic dedusting system runs for 1 year under horizontal and vertical, the independent generated energy lose 1.0241 and 0.8034 k W·h respectively. So the electricity consumption can be neglected in terms of the independent PV modules, however, the electricity consumption of large capacity photo-voltaic generation system in the process of dedusting can not be neglected. The running process of the system is scheduled before sunrise about 10 min and operated once in three days according to different regions and seasons; the average output powers of PV modules are increased by 1.5171%, 1.7312% and 9.6021% after dedusting and the ash depositions are collected for 3, 7 and 20 days. The more the amount of ash deposition is, the more obviously the automatic dedusting system runs. The automatic dedusting system can better improve the power generation efficiency of PV modules.Under the same external environment, different assemble angles have different amounts of the ash deposition of PV panels, and there are the optimum embedding angles of PV modules. The ash deposition will cause the optimum embedding angles to move. Studies on the influence law of the optimum embedding angle can guide the designing process of the photo-voltaic system and can enhance economic efficiency to a certain extent. In this paper, a research platform is built to test the law of the ash deposition and the output performance of PV modules in the range of 0°~90° and in the interval of 10°, to analyze the amount of the ash deposition of PV panels, the transmittance, and the variation law of the theory amount of radiation and the actual output power changed with the angles. This paper has proposed to characterize the dimensionless parameter of the influence degree of the optimum embedding angle affected by the ash deposition, which is called the influence degree of the ash deposition. The results show that, when taking the step of 10° and the angle of 90° as the reference, in the decreasing interval of 80°~0°, the increasing extents of the ash deposition are separately 17.24%, 22.41%, 43.10%, 62.07%, 60.34%, 68.97%, 87.93%, 91.38%and 93.10%. The no ash board is taken for the datum, the wavelength changes in the range of 350 ~ 770 nm, and the average transmittance decrease by 54.61%, 27.49%, 27.39%, 24.16%, 18.84%, 19.74%, 11.44%, 9.61%, 4.83%and 4.83% in the increasing interval of 0°~90°. This paper takes obtaining the maximum generated energy as the goal, the influence degrees of the theoretical embedding angle in decreasing order are 30°, 20°, 40°, 10°, 50°, 0°, 60°, 70°, 80° and 90°; the influence degrees of the actual embedding angle in decreasing order are 50°, 40°, 60°, 70°, 10°, 30°, 90°, 80°, 0°and 20°; the ash deposition makes the optimum embedding angle of PV modules move from 30° to 50° and the moving length is 20°; the influence degree of the ash deposition can optimize the optimum embedding angles of PV modules, the influence degree of the ash deposition changes from small to large, and the assemble angles are 50°, 40°, 70°, 60°, 10°, 30°, 80°, 90°, 0°and 20° successively. |
