A two-stage damage detection approach is proposed and experimentally demonstrated on a complicated spatial model structure with a limited number of measurements. In the experiment,five known damage patterns,including ...A two-stage damage detection approach is proposed and experimentally demonstrated on a complicated spatial model structure with a limited number of measurements. In the experiment,five known damage patterns,including 3 brace damage cases and 2 joint damage cases,were simulated by removing braces and weakening beam鈥揷olumn connections in the structure. The limited acceleration response data generated by hammer impact were used for system identification,and modal parameters were extracted by using the eigensystem realization algorithm. In the first stage,the possible damaged locations are determined by using the damage index and the characteristics of the analytical model itself,and the extent of damage for those substructures identified at stage I is estimated in the second stage by using a second-order eigen-sensitivity approximation method. The main contribution of this paper is to test the two-stage method by using the real dynamic data of a complicated spatial model structure with limited sensors. The analysis results indicate that the two-stage approach is ableto detect the location of both damage cases,only the severity of brace damage cases can be assessed,and the reasonable analytical model is critical for successful damage detection.展开更多
Back-to-back converters are the main components of a doubly-fed induction generator(DFIG).If the loadings of the rotor-side converter(RSC)and the grid-side converter(GSC)are balanced,the capacity and the cost of the D...Back-to-back converters are the main components of a doubly-fed induction generator(DFIG).If the loadings of the rotor-side converter(RSC)and the grid-side converter(GSC)are balanced,the capacity and the cost of the DFIG will be reduced.This paper balances the converters'loadings by adjusting reactive power of the GSC(Q_(g*)).The steady-state constraints of the DFIG are solved to quantify the imbalance degree.A sensitivity model of the unbalanced loading with respect to Q_(g*)is proposed to balance the loadings.To verify if loading adjustment reduces the stability of the DFIG,the eigen–sensitivity models,with respect to Q_(g*)and stator voltage,are newly proposed with the power flow Jacobian matrix.Numerical results verify the accuracy and efficiency of the proposed model.The loadings of the converters are balanced with a few adjustments.Loading balance has little negative impact on the stability of the DFIG.展开更多
基金supported by the National Natural Science Foundation of China (90815025, 90715032 and 50808013)
文摘A two-stage damage detection approach is proposed and experimentally demonstrated on a complicated spatial model structure with a limited number of measurements. In the experiment,five known damage patterns,including 3 brace damage cases and 2 joint damage cases,were simulated by removing braces and weakening beam鈥揷olumn connections in the structure. The limited acceleration response data generated by hammer impact were used for system identification,and modal parameters were extracted by using the eigensystem realization algorithm. In the first stage,the possible damaged locations are determined by using the damage index and the characteristics of the analytical model itself,and the extent of damage for those substructures identified at stage I is estimated in the second stage by using a second-order eigen-sensitivity approximation method. The main contribution of this paper is to test the two-stage method by using the real dynamic data of a complicated spatial model structure with limited sensors. The analysis results indicate that the two-stage approach is ableto detect the location of both damage cases,only the severity of brace damage cases can be assessed,and the reasonable analytical model is critical for successful damage detection.
基金supported by National Natural Science Foundation of China(No.51877061).
文摘Back-to-back converters are the main components of a doubly-fed induction generator(DFIG).If the loadings of the rotor-side converter(RSC)and the grid-side converter(GSC)are balanced,the capacity and the cost of the DFIG will be reduced.This paper balances the converters'loadings by adjusting reactive power of the GSC(Q_(g*)).The steady-state constraints of the DFIG are solved to quantify the imbalance degree.A sensitivity model of the unbalanced loading with respect to Q_(g*)is proposed to balance the loadings.To verify if loading adjustment reduces the stability of the DFIG,the eigen–sensitivity models,with respect to Q_(g*)and stator voltage,are newly proposed with the power flow Jacobian matrix.Numerical results verify the accuracy and efficiency of the proposed model.The loadings of the converters are balanced with a few adjustments.Loading balance has little negative impact on the stability of the DFIG.
