三相四线制APF的改进三电平SVPWM算法研究

三相四线制有源电力滤波器(Active Power Filter, APF)采用传统的三电平电压空间矢量脉宽调制算法没有考虑零轴电压分量,影响有源电力滤波器的谐波补偿效果。文中提出一种改进电压空间矢量脉宽调制算法,基于对零轴电压分量的分析,在传统电压空间矢量脉宽调制算法基础上调整正负小矢量作用时间,同时结合直流侧均压控制,从而改善三相四线制中点钳位型三电平三桥臂有源电力滤波器的谐波补偿效果。并在Matlab Simulink仿真验证该改进算法的正确性和可行性。     

三相四线制谐波检测新方法仿真研究

综合运用瞬时无功理论中的P-q方法和ip-iq方法,提出了一种基于瞬时无功理论的新的有效的三相四线制谐波检测新方法,将三相电流中的零序电流剔除,有效的解决了基于瞬时无功理论的传统有源滤波器在三相四线制电路中不适用.完善了P-q方法和ip-iq方法的不足,通过计算验证了该方法适用于任何三相电路,包括三相四线制电路,并且三相电压波形的畸变不影响检测结果的准确性.并用MATLAB仿真验证了方法的准确性和有效性,有效地解决了传统有源滤波器不适用于三相四线制电路的缺陷.     

基于滑模控制的三相四线制电力有源滤波器

建立了采用四桥臂逆变器为主电路的三相四线制电力有源滤波器的数学模型。该电力有源滤波器基于滑模的控制策略,采用指数趋近律的方法以减少抖动的影响。Matlab仿真结果表明,基于滑模控制策略的三相四线制电力有源滤波器具有很好的谐波抑制性能。     

三相三线APF补偿电流的模糊反馈检测与控制

补偿电流的检测是三相有源电力滤波器的关键问题,快速准确地检测出补偿电流并实施有效的控制直接影响到有源电力滤波器的补偿效果.对三相三线制有源电力滤渡器进行电路模型分析,采用T-S模糊反馈控制的方法,获得三相三线制有源电力滤波器的补偿电流,并对电源电流进行实时的模糊反馈控制.采用并行分布补偿的方法设计了模糊反馈控制器,将有源电力滤波器的非线性问题线性化,在稳定性条件下求解线性矩阵不等式,得到无功功率及谐波电流全补偿控制策略的状态反馈增益,由此获得连续的即时补偿跟踪电流,仿真及实验结果验证了补偿电流检测的准确性及模糊反馈控制的有效性,对简化有源滤波器的电流检测与其构成组件具有较大应用价值.     

有源电力滤波器中谐波检测算法分析与参数设计

有源电力滤波器控制的关键技术之一就是谐波检测,如何快速准确的检测出负载电流中的谐波成分是有源电力滤波器设计与实现中的一个重要部分。文章针对ip-iq法在实际应用中的不足进行了分析与改进,改进后的算法能够适用于三相三线、三相四线制系统,并能够分别检测出任意次零序、正序、负序谐波分量,针对改进后的算法进行了滤波器的参数设计,最后给出了在Matlab中仿真测试得到的结果。     

基于DSP的三相四线制有源滤波器的研究

针对配电网三相四线制系统的谐波、零线抑制以及有源电力滤波器补偿的实时性问题,提出了双DSP控制的三相四桥臂有源电力滤波器方案。主电路采用三相四桥臂结构的逆变器,由其产生的补偿电流与负载的有害电流分量大小相等,方向相反,从而使经该滤波器补偿后,电源电流的谐波和零线电流得到很好的抑制。数字控制方面主要由两片TMS320F2812DSP芯片完成。一片DSP主要负责信号数据采集;另一片DSP主要负责指令电流的运算。这样可以大大提高系统的运行速度,保证了有源电力滤波器补偿的实时性。本文介绍了三相四桥臂有源电力滤波器的数学模型、工作原理、检测和控制方式,并对系统的硬件构成和软件主程序流程作了阐述。通过MATLAB软件仿真验证了此方案的可行性。     

一种用于飞机交流电源系统的有源滤波器

针对飞机三相四线制电源系统的特点及现有电能质量控制方法的不足,提出了一种基于自适应陷波器、瞬时对称分量算法及滞环电流控制方式的飞机交流电源的有源滤波器。所提方法能够有效地消除飞机交流电源电流中的谐波及中线电流,补偿无功以及平衡三相电流。理论推导和仿真结果表明,该方法能够准确快速地检测出飞机三相四线制电源系统中的谐波电流,具有较好的动静态性能。     

串联混合有源电力滤波器的SRF控制

串联混合有源电力滤波器是为解决供电质量问题而设计的一种有源滤波器,谐波检测的方法对于有源滤波器技术的研究尤为重要.根据通用瞬时功率理论,针对传统的检测方法在三相电压不对称或畸变情形下的不足,提出一种基于同步参考坐标法的谐波电流检测方法,并将该方法成功地应用于三相电压不对称及畸变的串联混合有源电力滤波器补偿电路中.使用PSIM搭建谐波检测电路以及串联混合有源电力滤波器电路,进行了仿真.理论分析和仿真结果均表明,这种谐波电流检测方法的有效性.     

基于自适应逆控制的有源滤波器的检测算法

提出一种新的并联型电力有源滤波器的检测方法,通过控制有源滤波器直流电容电压来确定电网电流所需的基波有功分量的幅值,首次将自适应逆控制用于电力有源滤波器.将系统的主电路部分及有源滤波器看作广义有源滤波器,通过自适应逆控制方式控制直流电容电压,使其输出跟随参考输入,最终达到抑制谐波和补偿无功的目的.此检测算法简单有效,稳态和暂态的仿真结果均证实了该算法的可行性.     

VK有源电力滤波器在电源电压畸变时的谐波提取方法

分析了有源滤波器（APF）基于旋转坐标系下进行坐标变换的谐波检测方法。该方法在电网电压畸变情况下能很好地检测和补偿电网中的谐波电流和无功电流。应用于三相三线制电路时,该方法可以计算任意次谐波电流的瞬时值。仿真与实验均验证了所提出的谐波检测方法的有效性,基于旋转坐标系下进行坐标变换的谐波检测方法的有源电力滤波器具有良好的工作性能。     

Current control for a shunt hybrid active power filter using recursive integral PI

This paper presents a current control method for a shunt hybrid active power filter （HAPF） using recursive integral PI algorithm. The method improves the performance of the HAPF system by reducing the influence of detection accuracy, time delay of instruction current calculation and phase displacement of output filter. Fuzzy logic based set-point weighing algorithm is combined in the control scheme to enhance its robustness and anti-interference ability. The proposed algorithm is easy to implement for engineering applications and easy to compute. Experiment results have verified the validity of the proposed controller. Furthermore, the proposed recursive integral PI algorithm can also be applied in the control of periodic current as in AC drivers.     

Hierarchical neuro-fuzzy current control for a shunt active power filter

This paper presents the design of a hierarchical neuro-fuzzy current control scheme for a shunt active power filter compared with a single fuzzy controller scheme. A single fuzzy controller scheme is presented first and an ANFIS based neuro-fuzzy controller is connected hierarchically to the first one to improve the performance. Simulation results show that harmonic compensation is achieved with both schemes, however switching performance is superior for hierarchical scheme. The method of switching controller development in this paper is new and can be applied to other power electronic converter applications for improved performance.     

Robust current and speed control of a permanent magnet synchronous motor using SMC and ADRC

A second-order ordinary differential equation model is originally constructed for the phase q current system of a permanent magnet synchronous motor (PMSM). The phase q current model contains the effect of a counter electromotive force (CEMF), which introduces nonlinearity to the system. In order to compensate the nonlinearity and system uncertainties, a traditional sliding mode controller (SMC) combined with a low-pass filter (also known as a modified SMC) is designed on the phase q current model. The low-pass filter overcomes chattering effects in control efforts, and hence improves the performance of the controller. The phase q current control system is proved to be stable using Lyapunov approach. In addition, an alternative active disturbance rejection controller (ADRC) with a reduced-order extended state observer (ESO) is applied to control the speed output of PMSM. Both SMC and ADRC are simulated on the PMSM system. The simulation results demonstrate the effectiveness of these two controllers in successfully driving the current and speed outputs to desired values despite load disturbances and system uncertainties.     

有源电力滤波器的自抗扰控制研究

针对采用PI控制器控制有源电力滤波器时存在谐波或基波电流指令而无法实现无静差调节,且数字化后会进一步增大稳态误差,使有源电力滤波器的补偿性能降低的问题,提出一种有源电力滤波器的自抗扰控制策略。该策略利用自抗扰控制器的非线性跟踪-微分器和扩张状态观测器分别处理参考输入和输出,并选择适当的状态误差,实现了对滤波的自动、精确补偿。仿真和实验结果表明,有源电力滤波器采用自抗扰控制策略后具有很强的鲁棒性、稳定性和适应性,控制性能有较大改善。     

基于神经网络的单相有源滤波器

有源滤渡器的控制是一个典型的非线性控制过程．非常适合用神经网络来实现．本文提出了一种应用于有源滤波器系统的神经网络控制器，神经网络控制器的输入是负载电流和补偿电流。输出是开关控制信号甩于控制有源滤波器产生补偿电流来抵消非线性负载的畸变电流。基于MATLAB/SIMULINK平台．建立了单相有源滤波器仿真模型．仿真结果表明所提出的神经网络控制器的有效性。     

Approximated fuzzy logic controlled shunt active power filter for improved power quality

Shunt active power filters have been widely used for power quality improvement. With the advancement in artificial intelligence techniques, the applications of fuzzy logic‐based control systems have increased manifolds. This paper proposes a reduced rule fuzzy logic controller (FLC) in the voltage control loop of a shunt active power filter (APF), which is approximating a conventional large rule FLC. The difference between the controlled outputs of two controllers is compensated by proposed compensating factors. The dynamic response and harmonic compensation performance of proposed 4‐rule approximated fuzzy logic controller (AFLC) is compared with 25‐rule FLC. A three‐phase shunt APF is used for harmonic and reactive power compensation. The proposed scheme is tested with randomly varying single and multiple non‐linear loads. The simulation results presented under transient and steady‐state conditions confirm that the proposed 4‐rule AFLC efficiently approximates the 25‐rule FLC. The proposed control methodology takes less computational time and computational memory as the numbers of rules are reduced significantly.     

Analysis and design of a robust odd-harmonic repetitive controller for an active filter under variable network frequency

Frequency variations in the electrical network may cause a dramatic performance decay in repetitive controlled active filters intended to remove odd-harmonic distortion in single-phase AC loads. This work presents an odd-harmonic repetitive controller for a shunt active power filter that addresses such a performance problem. This is achieved by means of an adaptive change of the sampling period of the digital controller. However, this action implies structural changes that may result in an overall destabilization of the closed-loop system. Hence, a small-gain theorem-based robust control design technique allows to obtain a controller which assures BIBO stability in the required sampling period interval. Experimental results validate the proposal.     

电网谐波分析与治理一体化系统的研制

针对越来越严重的电网谐波污染问题，提出了基于混合有源滤波器的解决方案——电网谐波分析与治理一体化系统。介绍了其结构、原理和功能，重点阐述了谐波的检测与分析、系统控制信号产生等内容。实验表明，系统对各电量的检测误差均小于2％，电网三相电压总畸变率和电流总畸变率均大幅下降。电网谐波分析与治理一体化系统对于有效治理谐波、净化电气环境以及电网的科学化管理具有积极意义。     

Adaptive fuzzy backstepping control of three-phase active power filter

A backstepping controller (BC) and an adaptive fuzzy backstepping controller (AFBC) are proposed for three-phase active power filter (APF) in this paper. Firstly, the dynamic model for APF is build in which both the system parameter variations and external disturbance are considered. Then, the backstepping method is applied in the design of current control system to deal with the nonlinearity of APF. Moreover, the AFBC is developed by combining the backstepping approach with adaptive fuzzy strategy to attenuate the effect of parameter uncertainties and external disturbances. Fuzzy logic system is designed to estimate the unknown nonlinear function in the AFBC where the parameters are adjusted online by the adaptive law derived from the Lyapunov stability analysis to guarantee the tracking performance and stability of the closed-loop system. Simulation studies using the MATLAB/SimPower Systems Toolbox demonstrate that the proposed control strategies exhibit excellent performance in both steady state and transient operation.