Key Techniques of High-voltage and Large-capacity Series Hybrid Active Power Filters

基于基波磁通补偿的串联混合型有源电力滤波器（active power filter,APF）应用于高电压、大容量的谐波抑制场合时,受变压器励磁支路谐波电压的影响,逆变器不能等效为基波电流源,其输出电流将含有大量的谐波,从而影响滤波效果。以逆变器为核心,推导出在励磁支路谐波压降影响下的串联变压器的谐波等效阻抗。并以此为基础,从理论上分析励磁电感和变比对串联变压器谐波等效阻抗和APF滤波效果的影响。仿真结果验证了理论分析的正确性。最后,针对广东某厂10kV、1MVA电力负荷,研制一套基于基波磁通补偿的串联混合型有源滤波器工程样机,取得非常好的滤波效果。

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.

Sliding Mode Controller for Three-Phase Hybrid Active Power Filter with Photovoltaic Application

This paper presents a new three-phase hybrid active power filter configuration that interconnects a passive high-pass filter in parallel with an active power filter and a photovoltaic system. The proposed configuration can improves the filtering performance of the conventional active power filter, as well as simultaneously supply the power from the photovoltaic arrays to the load and utility. This paper will describe the proposed hybrid active power filter control using sliding mode with photovoltaic system. The proposed technique effectively filters harmonics under 1 kHz but also higher frequency to achieve wideband harmonics compensation. The THD of source current is reduced from 30.09% to 1.95%. The result indicates that the sliding mode controller can track the reference signals and have good dynamic characteristics.

Decoupling control and zero dynamics stabilization for shunt hybrid active power filter

An inverse system method based optimal control strategy was proposed for the shunt hybrid active power filter(SHAPF)to enhance its harmonic elimination performance.Based on the inverse system method,the d-axis and q-axis current dynamics of the SHAPF system were decoupled and linearized into two pseudolinear subsystems.Then,an optimal feedback controller was designed for the pseudolinear system,and the stability condition of the resulting zero dynamics was presented.Under the control strategy,the current dynamics can asymptotically converge to their reference states and the zero dynamics can be bounded.Simulation results show that the proposed control strategy is robust against load variations and system parameter mismatches,its steady-state performance is better than that of the traditional linear control strategy.

SHAPF的电流控制策略及参数设计

为了实现并联混合型有源电力滤波器(SHAPF)高补偿性能的要求,提出一种SHAPF电流双闭环控制策略。利用基波电流环为谐波电流环控制器提供阻尼项,实现有源阻尼的同时减少一组传感器,降低系统复杂度。分析了SHAPF的滤波特性,并给出了SHAPF系统配置的参数设计方法。分析了电流双闭环控制器在离散系统中的稳定性条件,并给出了控制器参数设计方法。搭建了SHAPF的仿真模型与实验样机。结果表明SHAPF具备良好的谐波补偿性能,验证了电流双闭环控制策略及参数设计的合理性。

基于LADRC的SHAPF模型及其电流跟踪控制策略

针对一种适用于现有中高压配电系统的三相并联混合型有源电力滤波器,首先基于PWM原理建立了其状态空间模型,在此基础上设计出一种基于线性自抗扰控制技术的电流跟踪控制器。该控制器能够估计出系统所有不确定因素和外部干扰等引起的总扰动并进行补偿,实现指令电流的实时跟踪,其算法简单,易于实现,具有一定的工程应用价值。数字仿真和物理实验结果验证了等效模型的正确性和所设计的电流跟踪控制器的控制品质优于PI控制器。

基于阻抗判据的变电站并联电容器组串抗率选择方法

为保证谐波不超标,实际应用中一般先投入高串抗率电容器,高、低串抗率电容器动作次数存在着差异性和不均衡性,而高串抗率电容器的配置和使用带来更大的有功损耗,经济性较差。针对这一问题,本文提出一种基于阻抗判据的变电站并联电容器组串抗率选择方法。首先,获取公共连接点谐波数据,建立状态空间表达式,采用卡尔曼滤波算法和标准差最小原则估计系统谐波阻抗;然后,依据电能质量标准得出限值谐波阻抗,分析并联电容器组限值谐波阻抗、等值谐波阻抗与谐波放大倍数的关系,确定串抗率选择的阻抗判据;最后,通过仿真算例验证本文方法的有效性和合理性。结果表明,所提方法能降低并联电容器组配置时优先使用高串抗率电容器带来的有功损耗,提高经济性。

云粒子群优化神经PI控制器的SHAPF谐波补偿研究

分析了并联混合型电力滤波器(SHAPF)的工作原理,针对传统PI控制器参数调节的缺陷,提出了一种云粒子群优化BP神经网络的PI控制方案,设计了一种神经自适应PI控制器。通过仿真及实验验证:与传统PI控制器相比,该控制器结构简单,对系统的补偿精度较高,计算速度性能好,有更好的谐波补偿效果。

基于混合有源滤波器的准比例谐振控制策略

由于电力电子设备、软启动器及各个非线性负荷的大量使用导致电网中谐波问题日趋加重,针对并联型混合有源电力滤波器(HAPF)谐波抑制控制策略进行研究。在这个拓扑结构的基础上,首先建立其数学模型并设计准比例谐振控制器和比例积分控制器进行仿真。针对传统的比例积分控制方法补偿精度低,并且对交流信号不能实现无静差跟踪等效果不理想问题,提出了电流内环准比例谐振控制与混合有源电力滤波器直流侧电压外环比例积分控制器相结合的控制策略。在Matlab/Simulink中搭建模型,仿真结果显示,上述控制策略能够补偿由非线性负载带来的谐波电流,补偿后的电网电流总谐波失真(THD)降到3.68%,符合国家标准。

SHAPF线性自抗扰直流侧电压控制方法

并联混合型有源电力滤波器(shunt hybrid active power filter,SHAPF)是抑制中高压配电系统谐波的有效方法,本文根据线性自抗扰控制技术(linear auto disturbance rejection control technique,LADRC),设计出了SHAPF的直流侧电压控制系统.基于LADRC的控制器能够估计出系统所有不确定因素和外部干扰等引起的总扰动并进行补偿,补偿性能良好,其算法简单,易于实现,具有一定的工程应用价值.仿真结果验证了基于LADRC的控制策略的有效性.

基于Backstepping变换的SHAPF滑模控制方法

由于有源电力滤波器(APF)的谐波分量的检测复杂并且存在电流畸变谐波,基于Backstepping的方法提出了一种应用于并联型混合APF(SHAPF)的滑模控制方法。首先在三相静止坐标系中建立SHAPF的数学模型,然后变换到d,q坐标系下设计控制器。控制系统分为电流环和电压环,分别进行控制,电流环通过使李雅普诺夫函数的导数始终为负求得电流控制律,电压环采用滑模变结构控制方法进行控制,从而使直流侧电压能够保持平稳,有效降低了APF部分的容量,并且使得直流侧电压在负载发生变化时,仍可以保持平稳,有较好的鲁棒性,最后利用Matlab/Simulink进行了仿真,并在实验平台上验证了该算法有良好的稳态以及动态补偿效果。

A novel control scheme for simultaneous elimination of imbalance, disturbance and voltage harmonic in power systems

In recent years, the increasing application of nonlinear and unbalanced electronic equipment and large single phase loads have made voltage imbalance a serious problem in power distribution systems. A novel approach has been proposed to eliminate voltage imbalance and disturbances. The main strategy of this scheme is based on series active filter. By improving control circuit toward existing schemes and proposing a new strategy to control the voltage amplitude, simultaneous elimination of voltage imbalance, faults, voltage harmonics and also compensation of voltage drop in transmission lines become possible. Eventually, the voltage on the load side is a perfectly balanced three phase voltage with specific proper amplitude. The proposed scheme has been simulated in a test network and the results show high capability of this scheme for the complete elimination of imbalance without phase shift.

一种新型谐振混合型有源电力滤波器

针对某些场合特定次谐波含量严重超标,研究了一种新型谐振混合型有源电力滤波器(RHAPF)。该拓扑通过并联谐振的高阻抗特点来降低有源部分的基波电流,极大地减少有源部分的容量,通过串联谐振低阻抗的特点来进行特定次谐波抑制,提高RHAPF的特定次谐波补偿性能。通过建立RHAPF的电气模型,分析了RHAPF在不同情况下的谐波补偿性能。通过建立系统的数学模型,采用基于前馈解耦的控制策略对系统进行了控制器的设计。仿真及实验验证了RHAPF拓扑结构及控制策略的可行性,该RHAPF特定次谐波补偿性能良好,能够减少有源部分容量,适用于大功率应用场合。

基于双调谐结构的有源调谐型混合滤波器研究

针对无源滤波器滤波效果不确定、滤波器与电网阻抗间可能会出现谐振等固有问题,提出一种基于双调谐结构的有源调谐型混合滤波器(ATHPF)。该滤波器在结构上将有源滤波器与双调谐滤波器有机结合到一起;在控制策略上,采取用有源滤波器对无源滤波器进行连续自动调谐的控制策略。在建立系统等值电路和数学模型基础上,明确了双调谐滤波器参数摄动对无源滤波器的滤波效果影响,进一步分析了该混合滤波器基本滤波机理,并通过搭建实验平台进行验证。结果表明,该混合滤波器具有良好的滤波效果。

混合型有源电力滤波器双闭环控制

混合型有源滤波器(HAPF)是一种改善电能质量的装置,针对其无源器件容易造成直流侧电压难以控制以及系统谐振的问题,提出一种变流器输出电流和电感电压反馈的双闭环控制器。首先建立变流器输出电压和无源支路上电感电压的数学模型,但模型中存在大量耦合项,为了实现无静差控制,采用变量前馈的解耦方式消除耦合量。然后对系统控制进行设计,电感电压作为外环保证跟踪精度;选用变流器输出电流作为内环,加入系统有源阻尼,抑制系统谐振尖峰。最后仿真和实验结果表明,该控制策略提高了直流侧电压控制的动态响应速度和稳态精度,同时降低了谐振尖峰对系统稳定性的影响。

一种具备谐振抑制能力的新型SVC及控制策略

为了兼顾谐波治理需求,同时避免传统无源滤波器容易引起系统谐波谐振的问题,提出一种基于混合型有源滤波器(HAPF)的新型静止无功补偿器(SVC)结构,并量化推导了有源滤波部分的谐波控制系数的合理设计范围。在此基础上,提出一种基于同步旋转坐标和改进广义积分控制的HAPF控制策略,从频率特性角度剖析了闭环跟踪精度及控制稳定性,并进一步校核新型SVC的谐振抑制能力。最后,搭建新型SVC样机实验平台,验证了所提方法的可行性和有效性。

Application of powdered activated carbon coating to fabrics in a hybrid filter to enhance mercury removal

Elemental mercury(Hg0) is predominant constituent of flue gas emitted from coal-fired power plants. Adsorption has been considered the best available technology for removal of Hg0 from flue gas. However, adsorbent injection increases the amount of ash generated. In the present study, powdered activated carbon(PAC) was coated on polytetrafluoroethylene/glass fiber filters to increase Hg0 removal while concurrently reducing the amount of ash generated. The optimal PAC coating rate was determined in laboratory experiments to ensure better Hg0 removal with low pressure drop. When PAC of particle size less than 45 μm was used, and the areal density was 50 g/m2, the pressure drop remained under 30 Pa while the Hg0 removal efficiency increased to 15.8% from4.3%. The Hg0 removal efficiency also increased with decrease in filtration velocity. The optimal PAC coating rate was applied on a hybrid filter(HF), which was combined with a bag filter and an electrostatic precipitator in a single chamber. Originally designed to remove fine particulates matter, it was retrofitted to the flue gas control device for simultaneous Hg0 removal. By employing the PAC coating, the Hg removal efficiency of the HF increased to 79.79% from 66.35%. Also, a temporary reduction in Hg removal was seen but this was resolved following a cleaning cycle in which the dust layer was removed.