This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI c...This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI controller involves current feedforward together with space vector modulation(SVM)to control the MC output currents.This controller provides extra control flexibility in terms of the current error reduction,and it gives improved steady-state tracking performance.When the coefficient of current feedforward is equal to the load resistor(K=R),the steady-state error is effectively minimized even when regulating sinusoidal variables.The total harmonic distortion is also reduced.In order to comparatively evaluate the modified PI controller,a PR controller is designed and tested.Both the modified PI and PR controllers are implemented in the natural frame(abc)in a straightforward manner.This removes the coordinate transformations that are required in the stationary(αβ)and synchronous(dq)reference frame based control strategies.In addition,both controllers can handle the unbalanced conditions.The experimental and simulation results verify the feasibility and effectiveness of the proposed controllers.展开更多
We study the internal stabilization of steady-state solutions to a 2-species mutualistic reaction diffusion system via finite-dimensional feedback controllers. Our main idea is to use different internal controllers to...We study the internal stabilization of steady-state solutions to a 2-species mutualistic reaction diffusion system via finite-dimensional feedback controllers. Our main idea is to use different internal controllers to stabilize different steady-state solutions. The controllers axe provided by considering LQ problems associated with the lineaxized systems at steady-state solutions.展开更多
为提高有源电力滤波器(active power filter,APF)的补偿性能和动态响应,提出一种基于多同步旋转坐标的谐波电流控制策略,采用通过与某指定次正序或负序谐波角速度同步的旋转坐标变换,将该指定次谐波变为直流量,实现指定次谐波的检测和P...为提高有源电力滤波器(active power filter,APF)的补偿性能和动态响应,提出一种基于多同步旋转坐标的谐波电流控制策略,采用通过与某指定次正序或负序谐波角速度同步的旋转坐标变换,将该指定次谐波变为直流量,实现指定次谐波的检测和PI控制,从而实现对某指定次谐波电流的无静差补偿。完整的谐波电流控制器由多个独立不同角速度的谐波电流控制器叠加组成。建立了APF在谐波旋转坐标系下的数学模型,提出一种简单的电流耦合解耦策略。对指定次谐波电流控制器进行分析,从理论上证明了与传统的电流环控制方法相比,指定次谐波控制可提高补偿精度,并利用零极点对消方法对控制器参数进行了设计。实验结果验证了所提控制策略的优越性。展开更多
文摘This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI controller involves current feedforward together with space vector modulation(SVM)to control the MC output currents.This controller provides extra control flexibility in terms of the current error reduction,and it gives improved steady-state tracking performance.When the coefficient of current feedforward is equal to the load resistor(K=R),the steady-state error is effectively minimized even when regulating sinusoidal variables.The total harmonic distortion is also reduced.In order to comparatively evaluate the modified PI controller,a PR controller is designed and tested.Both the modified PI and PR controllers are implemented in the natural frame(abc)in a straightforward manner.This removes the coordinate transformations that are required in the stationary(αβ)and synchronous(dq)reference frame based control strategies.In addition,both controllers can handle the unbalanced conditions.The experimental and simulation results verify the feasibility and effectiveness of the proposed controllers.
基金supported by the Chinese NSF under grant 10671079
文摘We study the internal stabilization of steady-state solutions to a 2-species mutualistic reaction diffusion system via finite-dimensional feedback controllers. Our main idea is to use different internal controllers to stabilize different steady-state solutions. The controllers axe provided by considering LQ problems associated with the lineaxized systems at steady-state solutions.
文摘为提高有源电力滤波器(active power filter,APF)的补偿性能和动态响应,提出一种基于多同步旋转坐标的谐波电流控制策略,采用通过与某指定次正序或负序谐波角速度同步的旋转坐标变换,将该指定次谐波变为直流量,实现指定次谐波的检测和PI控制,从而实现对某指定次谐波电流的无静差补偿。完整的谐波电流控制器由多个独立不同角速度的谐波电流控制器叠加组成。建立了APF在谐波旋转坐标系下的数学模型,提出一种简单的电流耦合解耦策略。对指定次谐波电流控制器进行分析,从理论上证明了与传统的电流环控制方法相比,指定次谐波控制可提高补偿精度,并利用零极点对消方法对控制器参数进行了设计。实验结果验证了所提控制策略的优越性。
