An Advanced Universal Power Quality Conditioning System and MPPT method for grid integration of photovoltaic systems

A photovoltaic system usually produces power quality pollutions to the interfaced power systems without a proper functioning of active filters. At present, available active filters are unable to fully suppress power grid harmonics and distortions, worsening power quality conditions within the interfaced system. This paper presents an Advanced Universal Power Quality Conditioning System (AUPQS) to interface photovoltaic systems to a power grid. In the interfaced system, an improved series active filter is designed to generate output voltages to compensate all the source voltage deficiencies and to highly suppress the grid-end current harmonics and distortions, even under unbalanced non-linear load conditions. Also, an independent single-phase inverter is suggested at the load side instead of the source side to regulate the DC-link voltage. Hence, the distortions and harmonics generated by this single-phase inverter are absorbed by the shunt filter of the AUPQS. Finally, a hybrid maximum power point tracking (MPPT) approach is proposed for effective operation of photovoltaic systems even under sudden light intensity changes and solar cells temperature variations. The overall interfaced system is designed and developed using Matlab/Simulink software. The effectiveness of the proposed AUPQS and MPPT method is further validated by simulation results.     

串联型有源电力滤波器控制方式的研究

根据串联型有源电力滤波器的工作原理, 讨论了其检测电源电流和检测负载电压控制方式的原理、系统结构和特点。在此基础上分析了复合控制方式, 并对三种控制方式进行了对比研究。实验结果表明, 在对电压型谐波源进行补偿时, 串联型有源电力滤波器采用复合控制方式稳定性高, 谐波补偿效果好。     

An indirect current control of hybrid power filter for varying loads

This paper presents an indirect current control scheme of parallel hybrid power filter system (PHPF) with self-supporting dc bus to eliminate harmonics generated by the nonlinear load. The PHPF system consists of a shunt passive filter with an active filter (AF) in series with it connected at the point of common coupling (PCC) in parallel with nonlinear load. The AF is realized using a three-phase voltage source inverter (VSI) with self supported dc bus. The compensation principles and dynamics of the system are discussed in detail. A proportional-integral (PI) controller over average dc bus voltage of the AF connected in series with passive filter is used for the control of the PHPF. The modeling equations of the PHPF are derived for compensation of harmonics generated by a three-phase rectifier load. The effectiveness of proposed control technique of the PHPF is demonstrated through simulated results under the dynamics of change of loads.     

Harmonic current and voltage compensation using HSAPF based on hybrid control approach for synchronous reference frame method

This paper presents a Hybrid Series Active Power Filter (HSAPF) for compensation of source current and load voltage harmonics. The HSAPF combination consists of a small rated series active power filter and a shunt connected passive power filter. This combination is suitable for compensation of voltage-type as well as current-type harmonic producing load. The HSAPF uses the synchronous rotating reference frame method that based on hybrid control approach, which eliminate both source current as well as load voltage harmonics and also tests the performance of HSAPF for ideal voltage, non-ideal voltage and also at different loading conditions, etc.     

A new approach to harmonic compensation in power systems-a combinedsystem of shunt passive and series active filters

A novel approach to compensating for harmonics in power systems is presented. It is a combined system of a shunt passive filter and a small rated series active filter. The compensation principle is described, and some filtering characteristics are discussed in detail. Excellent practicability and validity to compensate for harmonics in power systems are demonstrated experimentally. Although the source harmonic voltage was only 1%, the source harmonic current reached about 10% before the series active filter was started. After it was started, no harmonic current flowed into the shunt passive filter. In addition, no harmonic voltage appeared at the terminals of the shunt passive filter, because the source harmonic voltage was applied to the series active filter. The total loss of the series active filter was less than 40 W. It is concluded that the combined system is far superior in efficiency to conventional shunt active filters     

大功率有源电力滤波器的建模与应用

为实现较好的滤波效果,确保系统安全稳定运行,针对大功率混合型有源电力滤波器的补偿电流是通过控制逆变器的输出电压来产生适当输出电流的情况,在考虑有源滤波器的输出滤波器的基础上,利用开关函数法建立了大功率混合型有源电力滤波器的数学模型,为将电流参考信号转化为电压参考信号进行控制提供理论依据。实验仿真和工程应用都表明根据系统数学模型所设计有源滤波器的控制器能达到较好的滤波效果。     

Nonlinear modeling and control of a photovoltaic fed improved hybrid DSTATCOM for power quality improvement

This paper proposes a low rating photovoltaic fed improved hybrid distributed static compensator (DSTATCOM) for the compensation of harmonics and reactive power. The proposed system satisfies the load active power demand with reduced power rating of the photovoltaic source for same load rating as compared to the standard L or LCL filters. The system is modeled and controlled by considering the non-linearity of the system. A dc voltage droop regulator is used to control the power flow from solar system and to maintain dc link voltage. To make the system robust, switching pulses for inverter is generated using sliding mode controller. The efficacy of proposed model with sliding mode controller over linearly controlled system is validated through simulation results. The proposed system prototype is developed and operated in real time to show the effectiveness of the system.     

A Sustainable Solar Photovoltaic Energy System Interfaced with Grid-Tied Voltage Source Converter for Power Quality Improvement

This paper deals with the design, modeling, and implementation of a photovoltaic (PV) array interfaced with a DC–DC boost converter feeding three-phase grid-tied voltage source converter. The system uses an Instantaneous Reactive Power Theory-based control algorithm and is operated in unity power factor mode. This three-phase shunt-connected solar PV energy conversion system is also used for load currents harmonics elimination, power factor correction, reactive power compensation, and grid currents balancing in a three-phase distribution system. A Perturb and Observe-based maximum power point tracking algorithm is used to generate maximum power from the PV array. This system is designed and modeled, and its performance is verified through simulation in MATLAB/Simulink. A prototype of the proposed renewable energy system is developed in the laboratory using a digital signal processor to validate its design and control.     

大功率混合型APF用于大型冶炼厂谐波治理

为消除电力系统谐波及其巨大危害,根据大型冶炼厂谐波治理的特点,提出了一种新颖的拓扑结构-大功率混合型有源滤波器,它将串联谐振注入型有源滤波器与无源滤波器并联混合,由电容静态补偿无功功率,由有源和无源部分共同抑制谐波。实践证明该装置具有较好的滤波效果和一定的无功补偿能力。     

一种用于高压混合有源电力滤波器的复合控制方法

针对一种适用于高压交流系统的混合有源电力滤波器结构,提出了新的复合控制方法,较好地满足了谐波补偿控制系统稳定性和补偿精度的要求。该方法能精确补偿事先指定的若干次负载谐波电流,同时能削弱泄漏到系统中其余次数的谐波电流,并可以阻尼滤波器支路和系统阻抗间可能的谐振。该方法滤波效果好,实现简单,适用于高压交流系统的谐波补偿。仿真和实验结果证明了复合控制方法的有效性。     

一种高性能串联混合有源电力滤波器拓扑的研究

对传统的串联混合型有源电力滤波器抑制谐波的基本原理做了定性分析。在此基础上提出了一种新型高性能的串联混合有源电力滤波器。与传统的串联有源滤波器或者串联混合有源电力滤波器相比，其有源部分仅仅需要对注入电网的原负载系统的部分低次谐波进行抑制，从而提高了逆变器直流端电压的利用率，因而能在不损失滤波性能的前提下有效降低了有源部分的容量。该文进行了详细的理论分析，并通过仿真与10kVA样机的实验验证了理论分析的可行性。     

铜电解整流装置用并联混合型有源电力滤波器

为解决铜电解装置运行时产生的电网谐波污染和低功率因数问题,提出了在10kV侧安装并联混合型有源电力滤波器进行谐波抑制和无功补偿的综合补偿方案并介绍了混合滤波器的系统构成,混合型有源滤波器的无源部分由滤除11、13次谐波,同时补偿无功功率的11、13次两个无源支路构成。有源部分采用注入式拓扑结构,用来动态滤除11、13次以外的其它次谐波。有源部分对改善无源部分的滤波性能和抑制无源部分与系统等效阻抗之间的谐振发挥了重要作用。给出的现场运行结果表明:研制的并联混合型有源电力滤波器能有效的抑制谐波和进行无功补偿。     

典型工业电网谐波及其混合有源滤波抑制

通过对广泛应用的变频器和中频感应加热电源供电系统谐波的测试,给出了畸变率在４２％以上电流谐波的定量结论,针地５０ｋＶＡ变频器谐波源,提出了一咱混全源电力滤波器（ＨＡＰＦ）的谐波治理方案,分析了其原理并进行了仿真和实验,结果表明该方案具有谐波抑制效果好和对电网谐波以及负载变化适应性强等优点。     

基于不对称级联逆变器的串联混合有源电力滤波器

提出了一种基于不对称级联多电平逆变器(ACMI)的串联混合有源电力滤波器(SHAPF)及其控制策略.其中,ACMI的各单元逆变器的输出额定电压呈3的幂次方增长,N个单元逆变器的级联可以输出3N电平的阶梯波电压.该SHAPF的串联有源部分被控制为一个幅值由负荷电压基波有效值偏差确定、相位与线路终端电压基波正序分量相同的基波正弦电流源,用同一个装置和同一套控制策略可以实现电源电压扰动(包括谐波、电压降落和不对称等)隔离、负荷谐波电流补偿、负荷节点电压基波幅值调整、线路终端功率因数调整和故障电流限制等功能.与传统SHAPF相比,该SHAPF具有功能多、控制简单、补偿效果好以及其串联有源部分开关损耗小和易于实现大容量化等优点.数学推导和仿真分析验证了该SHAPF及其控制策略的正确性和有效性.     

一种新型串联混合有源滤波器及其控制技术研究

混合型有源电力滤波器是当前有源滤波器研究领域的一个重要方向。针对传统有源电力滤波器存在的问题,本文提出了一种新型的基于LC串联谐振的串联混合有源电力滤波器。考虑到传统有源滤波器谐波补偿性能与系统稳定性之间存在矛盾,设计时在电路主回路中引入了串联超前校正环节（PD控制器）,并以此为基础,建立了系统的数学模型,对系统的频率特性和滤波特性进行了分析。仿真结果表明：该新型滤波器滤波性能好,控制方法简单,实用性高;校正环节使系统的相位裕度增大,稳定性提高,谐波补偿性能也得到改善。     

高压配电网电能质量综合补偿系统

提出了一种具有谐波与无功综合治理功能的高压配电网电能质量综合补偿系统,该系统主电路由注入式混合型有源电力滤波器(IHAPF)和晶闸管控制电抗器(TCR)组成。首先分析了系统的基本工作原理,并对高压配电网电能质量综合补偿系统的谐振抑制特性进行了研究;其次,对高压配电网电能质量综合补偿系统的控制方法进行了研究,提出了电压、电流双闭环的控制方法实现谐波与无功的综合动态治理;最后,对高压配电网电能质量综合补偿系统的整体性能进行了仿真和实验验证,结果表明该系统可以有效地实现谐波与无功的综合动态治理,并适用于配电网,达到高品质节能的目的。     

一种实用的串并联混合有源电力滤波器

设计了一种实用的串并联混合有源电力滤波器,分析了其结构、工作原理和滤波性能。在该滤波器中,串联在系统和谐波负载之间的零磁通变流器可自动对基波呈低阻抗、对谐波呈高阻抗,从而实时检测出剩余谐波电流流过变流器时产生的谐波电压降、实现滤波;逆变器可产生一个与检测到的谐波电压成正比的电压。通过将耦合变压器与无源电力滤波器串联后并入电网,减少了流入系统的谐波电流。实验结果验证了该滤波器设计原理的正确性,表明其能有效降低滤波器有源部分的容量,具有良好的滤波性能。     

基于模糊优化设计的混合滤波器——治理电气化铁道谐波的一种新方法

基于模糊集和模糊优化理论,就使用C型滤波器和有源滤波器相串联构成混合滤波器方案的优化配置问题提出了一种新方法,建立了模糊优化数学模型,提出了相应的算法,以此来综合解决电气化铁道谐波和无功补偿的多目标寻优问题。并以某牵引站为例进行了模糊寻优计算,得出的结果证明,该方法具有投资省、可提高功率因数、并可有效地抑制谐波等优越性。是利用C型滤波器和有源滤波器构成的混合滤波方案,是解决电气化铁道谐波治理和无功补偿综合问题的一种理想方法。     

适用于电气化铁路的单相注入式混合有源滤波器

提出了一种适用于电气化铁路的新型单相注入式混合有源滤波器。这种新型有源电力滤波器能够补偿一定的无功,注入支路通过添加基波谐振支路的方法大大降低了有源滤波器的容量,克服了电网基波电压对装置的影响。并详细分析了系统的滤波原理,提出了基于卡尔曼增益自调整的改进型动态谐波含量估计方法,能够快速准确的跟踪检测电网谐波电流,并且克服了电力机车等冲击性负荷引起的电网电压畸变对谐波检测精度的影响;提出了基于逆变器两侧能量平衡的电流控制方法使有源部分吸收或释放一定有功或无功功率及产生与注入支路回灌谐波电流相反的抑制电流,然后联合电网谐波电流跟踪控制以获得系统参考信号,保证了直流侧电压的稳定,提高了装置可靠性,增强了系统滤波性能。仿真和实验结果表明这种新型单相注入式混合有源电力滤波器可靠性较高,满足电气化铁路所带电力机车等冲击性负荷的要求,可获得良好的滤波效果。     

基于基波磁通补偿的串联混合型APF滤波特性分析

在基于基波磁通补偿的串联混合型有源电力滤波器(APF)中,由脉宽调制逆变器实现了一个受控基波电流源.串联变压器一次侧的系统电源与系统阻抗、无源滤波器和非线性负载共同作用,使串联变压器二次侧端口呈现一个谐波干扰电压,导致逆变器输出电流中含有一定谐波,影响了滤波器的滤波效果.文中以脉宽调制逆变器为核心,建立了滤波器的数学模型,并对其滤波特性进行了分析.提出了改善其滤波效果的3项有效措施,即适当增大逆变器输出滤波电感、合理选择串联变压器原副方变比、采用电压前馈控制技术.设计了一套基于数字控制的10 kVA APF样机,实验结果证明了原理分析的正确性.