The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electr...The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electrical energy. We used two TSA control models which differ in the method of disturbed currents detection, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives more promising results than the linear control method. When connecting a non-linear load (televisions, lamps, variable speed drives, etc.) directly to the public distribution network, the non-linear nature of the load causes the source current to be deformed due to the presence of harmonic currents and voltages. These harmonics thus generate a high reactive power, and therefore considerable electrical losses in the network. One of the solutions to reduce losses on the electricity grid is to incorporate an electronic circuit called a filter into the electricity grid. This work carried out a comparative study of two types of control of a three-phase shunt active filter (TSAF) in order to carry out a system for cleaning up electricity networks in order to improve the quality of electrical energy. We used two TSA control models that differ in the method of detecting disturbed currents, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives better results than the linear control method.展开更多
Recursive state estimation methods have aroused substantial attraction among many researchers and in particular, the drives research fraternity has shown increased interest in recent years. State estimators that surro...Recursive state estimation methods have aroused substantial attraction among many researchers and in particular, the drives research fraternity has shown increased interest in recent years. State estimators that surrogate direct measurements play an integral part in the operation of modern a.c. drives. Their robustness and accuracy are very much decisive for the performance of the drive. In this paper, a comparative analysis of the three nonlinear filtering schemes to estimate the states of a three phase induction motor on the simulated model is presented. The efficacy of Ensemble Kalman Filter (EnKF) against the traditional Jacobian based Filter or Extended Kalman Filter (EKF) and almost forbidden, hitherto least-attempted Unscented Kalman Filter (UKF) is very much exemplified. Theoretical aspects and comparative simulation results are investigated comprehensively with respect to three different scenarios viz., step changes in load torque, speed reversal, and low speed operation. Also, “Monte Carlo Simulation” runs have been exploited very extensively to show the superior practical usefulness of EnKF, by which the minimum mean square error (MMSE), which is often used as the performance index, ostensibly gets mitigated very radically by the proposed approach. The results throw light on alleviating the intrinsic intricacies encountered in EKF in parlance with the observer theory.展开更多
This work addresses the problem of estimating the states of nonlinear dynamic systems with sparse observations.We present a hybrid three-dimensional variation（3DVar） and particle piltering（PF） method,which combine...This work addresses the problem of estimating the states of nonlinear dynamic systems with sparse observations.We present a hybrid three-dimensional variation（3DVar） and particle piltering（PF） method,which combines the advantages of 3DVar and particle-based filters.By minimizing the cost function,this approach will produce a better proposal distribution of the state.Afterwards the stochastic resampling step in standard PF can be avoided through a deterministic scheme.The simulation results show that the performance of the new method is superior to the traditional ensemble Kalman filtering（EnKF） and the standard PF,especially in highly nonlinear systems.展开更多
在“三跨”输电线路张力放线施工中,一旦发生事故被牵导线可能跌落冲击下方跨越网,威胁被跨越物的安全稳定运行,因此提出一种基于激光点云与建筑信息模型(building information modeling,BIM)技术的“三跨”施工跨越网动力学响应分析方...在“三跨”输电线路张力放线施工中,一旦发生事故被牵导线可能跌落冲击下方跨越网,威胁被跨越物的安全稳定运行,因此提出一种基于激光点云与建筑信息模型(building information modeling,BIM)技术的“三跨”施工跨越网动力学响应分析方法。首先利用机载激光雷达采集“三跨”施工现场的三维点云数据,使用改进的布料模拟滤波算法分割得到跨越地形点云数据,使用基于点云空间维度特征与K-Means算法实现对跨越档两侧杆塔点云数据的高精度提取;其次根据提取的点云数据结合BIM技术对目标设备及施工环境进行逆向建模,通过不同地表物体的组装堆砌,并在其上搭建施工跨越网模型;最后通过模拟事故发生时导线对跨越网的冲击碰撞,探测跨越网的承载性能及其与被跨越物之间的动态净空距离。结果表明,该方法能够提前在实际施工环境中对跨越网的动力学性能进行分析,为输电线路跨越施工提供可靠的安全保障及数据支撑,具有一定的工程价值。展开更多
文摘The aim of this work is to comparatively study two types of control of a three-phase shunt active filter (TSAF) in order to realize a system of depollution of electrical networks so as to improve the quality of electrical energy. We used two TSA control models which differ in the method of disturbed currents detection, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives more promising results than the linear control method. When connecting a non-linear load (televisions, lamps, variable speed drives, etc.) directly to the public distribution network, the non-linear nature of the load causes the source current to be deformed due to the presence of harmonic currents and voltages. These harmonics thus generate a high reactive power, and therefore considerable electrical losses in the network. One of the solutions to reduce losses on the electricity grid is to incorporate an electronic circuit called a filter into the electricity grid. This work carried out a comparative study of two types of control of a three-phase shunt active filter (TSAF) in order to carry out a system for cleaning up electricity networks in order to improve the quality of electrical energy. We used two TSA control models that differ in the method of detecting disturbed currents, one linear and the other non-linear. The results show that the non-linear control method, although with high calculation blocks, gives better results than the linear control method.
文摘Recursive state estimation methods have aroused substantial attraction among many researchers and in particular, the drives research fraternity has shown increased interest in recent years. State estimators that surrogate direct measurements play an integral part in the operation of modern a.c. drives. Their robustness and accuracy are very much decisive for the performance of the drive. In this paper, a comparative analysis of the three nonlinear filtering schemes to estimate the states of a three phase induction motor on the simulated model is presented. The efficacy of Ensemble Kalman Filter (EnKF) against the traditional Jacobian based Filter or Extended Kalman Filter (EKF) and almost forbidden, hitherto least-attempted Unscented Kalman Filter (UKF) is very much exemplified. Theoretical aspects and comparative simulation results are investigated comprehensively with respect to three different scenarios viz., step changes in load torque, speed reversal, and low speed operation. Also, “Monte Carlo Simulation” runs have been exploited very extensively to show the superior practical usefulness of EnKF, by which the minimum mean square error (MMSE), which is often used as the performance index, ostensibly gets mitigated very radically by the proposed approach. The results throw light on alleviating the intrinsic intricacies encountered in EKF in parlance with the observer theory.
基金Project supported by the National Natural Science Foundation of China (Grant No. 41105063)
文摘This work addresses the problem of estimating the states of nonlinear dynamic systems with sparse observations.We present a hybrid three-dimensional variation（3DVar） and particle piltering（PF） method,which combines the advantages of 3DVar and particle-based filters.By minimizing the cost function,this approach will produce a better proposal distribution of the state.Afterwards the stochastic resampling step in standard PF can be avoided through a deterministic scheme.The simulation results show that the performance of the new method is superior to the traditional ensemble Kalman filtering（EnKF） and the standard PF,especially in highly nonlinear systems.
文摘在“三跨”输电线路张力放线施工中,一旦发生事故被牵导线可能跌落冲击下方跨越网,威胁被跨越物的安全稳定运行,因此提出一种基于激光点云与建筑信息模型(building information modeling,BIM)技术的“三跨”施工跨越网动力学响应分析方法。首先利用机载激光雷达采集“三跨”施工现场的三维点云数据,使用改进的布料模拟滤波算法分割得到跨越地形点云数据,使用基于点云空间维度特征与K-Means算法实现对跨越档两侧杆塔点云数据的高精度提取;其次根据提取的点云数据结合BIM技术对目标设备及施工环境进行逆向建模,通过不同地表物体的组装堆砌,并在其上搭建施工跨越网模型;最后通过模拟事故发生时导线对跨越网的冲击碰撞,探测跨越网的承载性能及其与被跨越物之间的动态净空距离。结果表明,该方法能够提前在实际施工环境中对跨越网的动力学性能进行分析,为输电线路跨越施工提供可靠的安全保障及数据支撑,具有一定的工程价值。
