Fan blade lightning stroke probability assessment method

Abstract

The invention belongs to the technical field of wind power generation lightning protection, and particularly relates to a fan blade lightning stroke probability assessment method. By considering thata traditional fan blade lightning stroke analysis method ignores the conditions subjected to upward lightning strokes, the invention provides the fan blade lightning stroke probability assessment method. The method comprises the following steps: firstly adopting a finite element method to calculate the distribution of thunderclouds and an electric field near a fan under a downward leading role; inthe downward leading development process of thunders and lightning, judging whether each sampling point on the surface of a fan blade is initial upward leading; recording the height from the corresponding downward leading head of thunders and lightning to the ground when upward leading is generated at the position of each sampling point on the fan blade; and finally establishing a fan blade lightning stroke probability assessment model so as to calculate the probability that any position on the surface of the fan blade is subjected to lightning strokes. According to the method, the probability of lightning strokes at any position of the blade can be calculated, and the probability distribution of the blade subjected to lightning strokes is analyzed, so that a theoretical analytical methodis provided for designing and assessing a fan blade lightning protection system.

Description

technical field [0001] The invention belongs to the technical field of lightning protection for wind power generation, and in particular relates to a method for evaluating the lightning strike probability of fan blades. Background technique [0002] In recent years, with the rapid development of wind power generation, the installed capacity and the number of units have continued to increase, and the problem of wind turbines being struck by lightning has become prominent, which seriously threatens the safe operation of wind farms. The effectiveness and reliability of wind turbine lightning protection system are very important to the field of wind turbine lightning protection. Most of the existing wind turbine lightning protection system designs refer to the IEC61400-24 technical standard. Aluminum air-body air-termination devices are installed equidistantly on the blade surface from the blade tip, and blade-tip air-termination devices are installed on the blade tip. Wire con...

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Problems solved by technology

As the unit capacity increases and the height of the wind turbine increases, the probability of the wind turbine being struck by upstream lightning also increases significantly. Since the IEC standard only considers the situation that the wind turbine is struck by the downlink lightning strike, the existing standard underestimates the probability of the wind turbine being struck by the upstream lightning strike caused by lightning. Happening

In addition, since the fan blade body is made of insulating material, and the lightning protection system is made of metal, the combination of the two is more complicated than that of the transmission line. The traditional lightning strike analysis method for fan blades can only obtain the lightning protection of the blade from a macro perspective. The protection effect of the system, but can not find the weak area of ​​its protection

Moreover, there are few existing theories on the protection range of wind turbine blade lightning receptors, and the relevant research is still incomplete. There is no analysis of the distribution of lightning strikes on ground objects at any position. For different blade attitudes and between different blades The impact of the interaction of wind turbines on the lightning protection system remains to be further studied

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