有源电力滤波器的定频滞环空间矢量控制策略研究

本文通过基于空间电压矢量（SVPWM）滞环电流控制策略,搭建了以DSP2407控制芯片为控制核心、定频滞环SVPWM为控制策略的有源电力滤波器控制系统,针对两种负载做了无功补偿实验,同时分析了在该控制策略下有源电力滤波器的补偿效果。实验结果验证了定频滞环SVPWM控制策略理论的正确性及可行性。     

并联型有源电力滤波器的SVPWM控制技术研究

针对有源滤波器常规滞环、三角载波控制时,开关频率波动大,响应慢的缺点,引入了空间电压矢量算法。在K步时,假定K+1步,APF的补偿电流完全跟踪上了谐波指令电流,再根据APF离散的数学模型及空间电压矢量调制模块,确定第K+1步的开关管驱动信号,以达到快速补偿谐波电流的目的。仿真实验表明,基于SVPWM控制的有源滤波器具有开关频率固定,动态响应快,补偿精度高的优点。     

基于PI控制的有源滤波器中的研究

提出了基于并联型三相三线制有源滤波器的优化设计的PI控制方法,该方法的优点是对检测到电流误差信号为控制对象,用滞环比较器构成区域判别器,在此基础上实行滞环电流控制。在同样的控制精度下,该方法可以有效得降低开关频率,减小有源滤波器开关损耗。计算机仿真结果验证了这一方法的有效性。     

并联型有源电力滤波器直流侧电压柔性控制策略

针对并联型有源电力滤波器的直流侧电压控制特点,提出了一种对直流侧电压进行柔性控制的并联型有源电力滤波器控制策略。该策略中,在直流侧电压控制部分引入反馈低通滤波器,削弱直流侧固有谐波对输出电流控制的影响;在电流控制的输出部分通过增加直流侧电压前馈系数,抵制在变换桥中可能引入的直流侧电压谐波影响。仿真结果表明直流侧电压柔性控制策略能够降低APF系统补偿后的电源电流总谐波畸变率,从而改善并联型有源电力滤波器的谐波补偿性能。     

基于TMS320LF2812的并联型有源电力滤波器的设计与实现

针对谐波抑制和无功补偿的问题,对有源电力滤波器进行一系列研究,阐述了有源电力滤波器的基本原理以及控制策略。基于TMS320LF2812设计了有源电力滤波器,包括DSP控制板、电压采样电路,电流采样电路以及IPM功率单元的设计,并给出了有源电力滤波器的软件设计。最后利用MATLAB仿真软件对所涉及的有源电力滤波器进行仿真,验证了有源滤波器系统的正确性以及谐波补偿电流和滞环比较控制模块的有效性。     

电力有源补偿及滞环电流跟踪控制研究

本文在对电力系统有源无功与谐波补偿的原理进行理论分析的基础上,运用其有关分析结果主要讨论一种电力有源滤波器主电路及变结构非线性控制系统的组成和工作原理,给出了一种变结构滞环电流跟踪控制的思路,通过Pspice软件对单相和三相系统进行了仿真研究,仿真结果证实了该系统及控制方法的正确性与可行性。     

有源电力滤波器电流控制PI校正研究

采用PI校正方法对并联有源电力滤波器电流环进行控制。通过对并联有源电力滤波器的开环幅频特性分析和PI校正分析,得到了并联有源电力滤波器电流环控制的校正参数。通过仿真实验,对有源电力滤波器的补偿精度进行分析,结果证明该校正方法能够取得较好的补偿效果。     

基于有源滤波器一种控制方法的仿真研究

影响有源电力滤波器性能的两个关键环节是谐波电流检测和电流跟踪控制环节.本文基于瞬时无功功率理论的谐波电流检测方法,采用了滞环电流控制方法,提出了电压电流双闭环控制策略,详细分析了其工作原理并进行了Matlab仿真试验,结果表明具有较好的滤波效果.     

三相整流桥直流侧和交流侧并联型有源电力滤波器比较研究

三相直流侧和交流侧有源电力滤波器均可用于三相不可控整流桥的谐波治理。从谐波补偿效果、有源滤波器的补偿容量、开关应力三个方面对二者进行了分析和对比。分析结果表明,由于直流侧有源电力滤波器并联在整流桥的直流侧,在换相处的负载电流变化率比交流侧小得多,因此直流侧有源电力滤波器的补偿性能优于交流侧有源电力滤波器。同时由于直流侧有源电力滤波器工作在电压电流两个象限,因此其补偿容量和开关应力远小于交流侧有源电力滤波器。     

LCL滤波器在并联型有源电力滤波器中的设计

在满足相同的高频滤波效果的情况下,LCL滤波器所需的总电感值比L滤波器小,因此更适于在大功率、开关频率较低的电流源控制型并网设备上应用。然而针对该类型滤波器的参数设计不仅关系到开关频率处纹波抑制效果,同时也会影响电流控制器的性能。随着高频谐波抑制效果明显的LCL滤波器在并联型有源滤波器中应用,基于谐波电流跟踪控制器的LCL参数设计需要进一步研究,因此文中基于并联型有源电力滤波器给出一套LCL滤波器设计方法,并通过仿真验证该LCL滤波器的有源电力滤波器的有效性。     

一种高精度压电换能器导纳仪的研究

压电换能器的一致性检测需要导纳圆测量仪器.给出了基于高速模数转换器和ARM7控制器的数字式压电换能器导纳圆测量系统.用ARM7控制生成不同频率的正弦信号,用高速A/D转换器同时采集两路原始测量波形,用数字信号处理方法处理原始波形的相位差和幅度比,从而得到导纳圆.与模拟式导纳仪相比,基于ARM控制器的数字式压电换能器导纳仪消除了低频滤波器的影响,能有效测量低频区域.与基于采集卡的数字式导纳仪和4294A测量结果对比显示,基于ARM7的导纳仪测量精度有了一定的提高.     

On the DSP-based switch-mode rectifier with robust varying-band hysteresis PWM scheme

This paper presents the development of digital signal processor (DSP) based switch-mode rectifier (SMR) with robust varying-band hysteresis current-controlled (HCC) pulse width modulated (PWM) schemes. First, a robust fixed-frequency HCC PWM control scheme is developed. Through robust harmonic spectrum shaping, the constant frequency control performance is insensitive to the changes of system parameters and operating condition, and the low frequency harmonics possess smaller magnitudes. Next, the robust HCC PWM schemes of SMR with linearly and randomly varying hysteresis bands are proposed. The harmonic spectra of the SMR are shaped to be uniformly distributed. As to the output voltage regulation control, the dynamic plant model is first estimated. Then accordingly, the controller is quantitatively designed to meet the prescribed control requirements. Significant power quality improvement in line drawn current for the SMR is achieved by using the developed HCC PWM schemes.     

Experimental design of a fuzzy controller for improving power factor of boost rectifier

This article presents the design and the implementation of dSPACE DS1104 controller board-based PI and fuzzy logic peak current-mode controllers in the voltage loop and two controllers in the current loop based first on a standard fixed hysteresis band control, followed by a variable hysteresis band control to achieve constant switching frequency for a single-phase active power factor corrector in the continuous conduction mode. All these controllers have been verified via simulation in Simulink and a real-time implementation is performed on an experimental test bench utilising a rapid prototyping tool. The controllers are experimentally compared for steady-state performance and transient response. It is shown that the PI and fuzzy logic controllers give a superior steady-state performance, whereas the fuzzy logic inference based controller can achieve better dynamic response than its PI counterpart under large load disturbance and plant uncertainties. Furthermore, the variable hysteresis band control in the current loop gives a low total harmonic distortion of the input current compared to a standard fixed hysteresis band control.     

A robust hysteresis current-controlled PWM inverter for linear PMSMdriven magnetic suspended positioning system

Hysteresis current-controlled pulsewidth modulation (PWM) is very robust but it possesses nonconstant switching frequency, and it is difficult to use for high-performance position servo applications. This paper presents a robust hysteresis current-controlled PWM scheme for a magnetic suspended positioning system driven by an inverter-fed linear permanent-magnet synchronous motor having improved performance in these two areas. In the proposed control scheme, the conventional hysteresis PWM mechanism is augmented by a robust harmonic spectrum-shaping controller. The error signal, which represents the switching frequency deviated from the set one, is detected using a notching filter inverse model. Then, the current command is adjusted by a robust compensation signal. The hysteresis band can be equivalently varied to let the dominant harmonic frequency of inverter output be constant, wherein the frequency can easily be changed by tuning the center frequency of the notch filter. The gating signal of switches is not needed to be sensed for making the proposed control. The constant-frequency control performance yielded by the proposed controller is rather insensitive to the system disturbances and the neutral voltage variation due to isolated Y connection. Through applying the proposed PWM inverter, satisfactory position control requirements can be achieved by properly setting the dominant harmonic frequency according to the electromechanical model of the positioning system     

Experimental characterization and modeling of rate-dependent hysteresis of a piezoceramic actuator

Laboratory experiments were performed to characterize the rate-dependent hysteresis properties of a piezoceramic actuator under harmonic, complex harmonic and triangular excitations in the 0.1–500 Hz frequency range. The measured data were analyzed to describe the major and minor hysteresis loops as functions of frequency, magnitude and bias of the input voltage. The results revealed considerably larger hysteresis loop width and lower displacement response amplitude under frequencies above 10 Hz. A rate-dependent Prandtl–Ishlinskii model is developed for describing the rate-dependent hysteresis behaviour of the actuator. This model integrates rate-dependent play operator and density functions formulated on the basis of the rate of change of input and experimentally observed behaviors. The fundamental properties of the proposed rate-dependent play and stop hysteresis operators are also investigated. The model results attained under harmonic, complex harmonic and triangular inputs at different frequencies in the 0.1–500 Hz were compared with the corresponding experimental data to demonstrate model validity over the wide range of inputs. Very good agreements were observed between the model results and the measured data, irrespective of the type and frequency of excitation.     

基于环流反馈的逆变器并联系统仿真分析

对于逆变器并联系统,各模块输出电压之间如若存在幅度和相位上的差异,势必会产生在模块间流动的环流。文中在逆变器并联系统环流产生机理分析的基础上,对是否加入环流反馈时系统的阻抗和稳定性进行了分析,证明采用环流反馈可以增大系统环流阻抗,在保持输出电压不变的前提下有效地减小了环流,最后通过Simulink仿真证明此方式的有效性。     

Modulation strategy for single phase PWM inverters

A novel pulse width modulation (PWM) strategy that closely approximates the harmonic performance of the off-line harmonic minimised PWM technique for single phase PWM inverters is presented. The proposed on-line PWM technique digitally reproduces the characteristics of hysteresis band modulation for which the switching frequency is directly controlled by adapting the width of the hysteresis band. The software implementation is achieved using the conventional equations for regular-sampled PWM, combined with the pulse-position modulation (PPM) function characteristic of hysteresis band modulation     

Hysteresis describing method for control of an active power filter

A hysteresis describing method is proposed to control and design an active power filter. The describing function used to develop this method consists of the linearisation of the non-linear current control loop. The linearisation is done by deriving the hysteresis complex describing function to find the stability condition of the closed-loop current. Under this condition, the frequency and amplitude values of the error signal correspond to the maximum switching frequency and the current ripple, respectively. The proposed method permits calculation of these parameters in a simple algebraic equation as a function of the hysteresis band, dc bus voltage and inductive filter value. Moreover, the compromise between the dc bus voltage and inductor value can be evaluated easily as a function of both switching frequency and ripple requirements. Two design examples are worked out. Experimental results validate the theory.     

基于谐波测量的改进余弦窗函数

电网电压监测设备在监测运行设备的电流电压波形时通常采用谐波分析法,针对传统FFT谐波分析法在电网频率波动时谐波测量会产生栅栏效应和频谱泄漏的问题,在研究余弦窗特性的基础上提出了一种改进3项余弦窗。通过频谱衰减曲线与传统余弦窗对比,采用基于数据样本的非线性拟合方法,拟合出了改进窗插值算法的谐波幅值相位修正系数,使改进窗插值算法能实际应用于谐波测量。通过谐波测量仿真对比,验证了加改进余弦窗的谐波测量准确度更高。     

有源电力滤波器空间矢量滞环控制的研究

针对因非线性负载引起的电网谐波污染问题,引入有源电力滤波器(Active power filter,APF)进行治理.分析滞环比较法的工作过程并指出不足,引入空间矢量法解决输出电压相间干扰问题.改进APF的控制策略,把滞环比较和空间矢量结合起来实现电流跟踪控制.最后通过MATLAB/Simulink仿真,比较两种控制策...