In order to solve the linear variable differential transformer （LVDT） displacement sensor nonlinearity of overall range and extend its working range, a novel line-element based adaptively seg- menting method for pie...In order to solve the linear variable differential transformer （LVDT） displacement sensor nonlinearity of overall range and extend its working range, a novel line-element based adaptively seg- menting method for piecewise compensating correction was proposed. According to the mechanical structure of LVDT, the output equation was calculated, and then the theoretic nonlinear source of output was analyzed. By the proposed line-element adaptive segmentation method, the nonlinear output of LVDT was divided into linear and nonlinear regions with a given threshold. Then the com- pensating correction function was designed for nonlinear parts employing polynomial regression tech- nique. The simulation of LVDT validates the feasibility of proposed scheme, and the results of cali- bration and testing experiments fully prove that the proposed method has higher accuracy than the state-of-art correction algorithms.展开更多
This paper introduces an adaptive finite element method （AFEM） using the newest vertex bisection and marking exclusively according to the error estimator without special treatment of oscillation. By the combination ...This paper introduces an adaptive finite element method （AFEM） using the newest vertex bisection and marking exclusively according to the error estimator without special treatment of oscillation. By the combination of the global lower bound and the localized upper bound of the posteriori error estimator, perturbation of oscillation, and cardinality of the marked element set, it is proved that the AFEM is quasi-optimal for linear elasticity problems in two dimensions, and this conclusion is verified by the numerical examples.展开更多
传统有限控制集模型预测控制FCS-MPC(finite control set model predictive control)策略需要建立准确的数学模型,当其应用于LCL型并网逆变器时则需多个电流电压传感器,若采样数据类型过少必然会产生建模误差。针对实际应用中传感器较...传统有限控制集模型预测控制FCS-MPC(finite control set model predictive control)策略需要建立准确的数学模型,当其应用于LCL型并网逆变器时则需多个电流电压传感器,若采样数据类型过少必然会产生建模误差。针对实际应用中传感器较少引起的预测模型参数失配问题,研究了一种基于自适应线性神经元ADALINE(adaptive linear neuron)算法的模型预测控制策略。该方案将ADALINE算法用于在线更新预测模型的计算参数,提高了预测模型的参数鲁棒性;同时对控制器延时进行了补偿,提高了控制精度。仿真和实验结果表明,该方案有效减少了并网电流谐波含量,并且具有优良的瞬态性能,验证了该方案的可行性和有效性。展开更多
Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the...Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the direction or magnitude of the field is changing rapidly,the smallest elements are demanded due to high accuracy to use adaptive meshing technique.The co-simulation was used with the status space functions and time-step finite element functions,in which time-step of the status space functions was the smallest than finite element functions'.The magnitude relation of the normal elec- tromagnetic force and tangential electromagnetic force and the period were attained,and current curve was very abrupt at current zero area due to the bigger resistance and leak- age reactance,including main characteristics of motor voltage and velocity.The simulation results compare triumphantly with the experiments results.展开更多
In this paper, we derive a posteriori error estimators for the constrained optimal control problems governed by semi-linear parabolic equations under some assumptions. Then we use them to construct reliable and effici...In this paper, we derive a posteriori error estimators for the constrained optimal control problems governed by semi-linear parabolic equations under some assumptions. Then we use them to construct reliable and efficient multi-mesh adaptive finite element algorithms for the optimal control problems. Some numerical experiments are presented to illustrate the theoretical results.展开更多
为提高无位置传感器内置式永磁同步电动机(IPMSM)控制性能,提出一种改进的基于反电动势模型的自适应滤波转子位置观测器。针对逆变器非线性和磁场空间谐波引起扩展反电动势6k±1次谐波,进而产生6k次转子位置脉动观测误差问题,提出...为提高无位置传感器内置式永磁同步电动机(IPMSM)控制性能,提出一种改进的基于反电动势模型的自适应滤波转子位置观测器。针对逆变器非线性和磁场空间谐波引起扩展反电动势6k±1次谐波,进而产生6k次转子位置脉动观测误差问题,提出一种基于递归最小二乘算法自适应线性神经元滤波器的转子位置观测方法,从而实现IPMSM矢量控制系统准确解耦控制。该方案能够在线连续调整权重分量,保证了转子位置观测器的快速收敛性。通过自适应滤波器滤除指定的反电动势观测值谐波分量,从而提高正交软件锁相环获得转子位置信息的准确度。最后通过模型仿真和2.2k W IPMSM无传感器矢量控制系统验证了控制策略的有效性。展开更多
基金Supported by National High Technology Research and Development Program of China("863" Program)(2011AA041002)
文摘In order to solve the linear variable differential transformer （LVDT） displacement sensor nonlinearity of overall range and extend its working range, a novel line-element based adaptively seg- menting method for piecewise compensating correction was proposed. According to the mechanical structure of LVDT, the output equation was calculated, and then the theoretic nonlinear source of output was analyzed. By the proposed line-element adaptive segmentation method, the nonlinear output of LVDT was divided into linear and nonlinear regions with a given threshold. Then the com- pensating correction function was designed for nonlinear parts employing polynomial regression tech- nique. The simulation of LVDT validates the feasibility of proposed scheme, and the results of cali- bration and testing experiments fully prove that the proposed method has higher accuracy than the state-of-art correction algorithms.
基金Project supported by the National Natural Science Foundation of China(Nos.1120115911426102+4 种基金and 11571293)the Natural Science Foundation of Hunan Province(No.11JJ3135)the Foundation for Outstanding Young Teachers in Higher Education of Guangdong Province(No.Yq2013054)the Pearl River S&T Nova Program of Guangzhou(No.2013J2200063)the Construct Program of the Key Discipline in Hunan University of Science and Engineering
文摘This paper introduces an adaptive finite element method （AFEM） using the newest vertex bisection and marking exclusively according to the error estimator without special treatment of oscillation. By the combination of the global lower bound and the localized upper bound of the posteriori error estimator, perturbation of oscillation, and cardinality of the marked element set, it is proved that the AFEM is quasi-optimal for linear elasticity problems in two dimensions, and this conclusion is verified by the numerical examples.
文摘传统有限控制集模型预测控制FCS-MPC(finite control set model predictive control)策略需要建立准确的数学模型,当其应用于LCL型并网逆变器时则需多个电流电压传感器,若采样数据类型过少必然会产生建模误差。针对实际应用中传感器较少引起的预测模型参数失配问题,研究了一种基于自适应线性神经元ADALINE(adaptive linear neuron)算法的模型预测控制策略。该方案将ADALINE算法用于在线更新预测模型的计算参数,提高了预测模型的参数鲁棒性;同时对控制器延时进行了补偿,提高了控制精度。仿真和实验结果表明,该方案有效减少了并网电流谐波含量,并且具有优良的瞬态性能,验证了该方案的可行性和有效性。
基金National Natural Sciences Foundation(60474043)Henan Province Science Fund for Distinguished Young Scholars(0412002200)Henan Province Major Projects(0223025300)
文摘Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the direction or magnitude of the field is changing rapidly,the smallest elements are demanded due to high accuracy to use adaptive meshing technique.The co-simulation was used with the status space functions and time-step finite element functions,in which time-step of the status space functions was the smallest than finite element functions'.The magnitude relation of the normal elec- tromagnetic force and tangential electromagnetic force and the period were attained,and current curve was very abrupt at current zero area due to the bigger resistance and leak- age reactance,including main characteristics of motor voltage and velocity.The simulation results compare triumphantly with the experiments results.
文摘In this paper, we derive a posteriori error estimators for the constrained optimal control problems governed by semi-linear parabolic equations under some assumptions. Then we use them to construct reliable and efficient multi-mesh adaptive finite element algorithms for the optimal control problems. Some numerical experiments are presented to illustrate the theoretical results.
文摘为提高无位置传感器内置式永磁同步电动机(IPMSM)控制性能,提出一种改进的基于反电动势模型的自适应滤波转子位置观测器。针对逆变器非线性和磁场空间谐波引起扩展反电动势6k±1次谐波,进而产生6k次转子位置脉动观测误差问题,提出一种基于递归最小二乘算法自适应线性神经元滤波器的转子位置观测方法,从而实现IPMSM矢量控制系统准确解耦控制。该方案能够在线连续调整权重分量,保证了转子位置观测器的快速收敛性。通过自适应滤波器滤除指定的反电动势观测值谐波分量,从而提高正交软件锁相环获得转子位置信息的准确度。最后通过模型仿真和2.2k W IPMSM无传感器矢量控制系统验证了控制策略的有效性。
