Calculation of Lightning Transient Responses on Wind Turbine Towers

Abstract

An efficient method is proposed in this paper for calculating lightning transient responses on wind turbine towers. In the proposed method, the actual tower body is simplified as a multiconductor grid in the shape of cylinder. A set of formulas are given for evaluating the circuit parameters of the branches in the multiconductor grid. On the basis of the circuit parameters, the multiconductor grid is further converted into an equivalent circuit. The circuit equation is built in frequency-domain to take into account the effect of the frequency-dependent characteristic of the resistances and inductances on lightning transients. The lightning transient responses can be obtained by using the discrete Fourier transform with exponential sampling to take the inverse transform of the frequency-domain solution of the circuit equation. A numerical example has been given for examining the applicability of the proposed method.

Calculation of Transient Potential Rise on the Wind Turbine Struck by Lightning

“…For the sake of simplification, the grounding system is modeled as a grounding resistance R g [ 1 , 4 ]. The value of R g is specified by the corresponding design standard [ 15 ].…”

“…Recently, a more detailed method has been presented. This method represents the tower as a cage-like multiconductor system [ 4 , 5 ] and can give the potential distribution on the WT; however, it causes a significant increase in the circuit complexity. For an improvement on the lightning transient calculation of WTs, a simplified circuit model is proposed in this paper.…”

Transient Simulation of Wind Turbine Towers under Lightning Stroke

“…For the sake of the transient analysis of the potential distribution on the tower, the blade and the conducting path in the nacelle are left out of consideration. Instead, lightning current is injected into the tower body from its top, as shown in Figure 1 [4]. In order to build the circuit model of the tower, the continuous conducting shell of the tower body needs to be subdivided into a discrete multiconductor system formed by longitudinal and transverse branches, as illustrated in Figure 2 [5].…”

“…Equations (3) and (4) indicate that the calculation of the mutual inductance depends on the double line integrals ( , ) and ( , ). From the viewpoint of integral operation, the way to evaluate ( , ) is the same as that to evaluate ( , ).…”

Assessment of wind turbine transient overvoltages when struck by lightning: experimental and analytical study

“…An efficient algorithm has been proposed for evaluation of the transient responses on WT towers struck by lightning [17][18][19]; however, the blades were not taken into account in their simulation. Also, the tower was divided into vertical cylinders [17][18][19] and each cylinder was split by a wire grid composed of horizontal and vertical current segments like a cage. This reflects itself on the complexity of the calculations because of the mutual effect between current segments.…”