【作者】 沈小莉；

【导师】 周林；

【作者基本信息】 重庆大学 ， 电气工程， 2004， 硕士

【摘要】 随着谐波问题的日益严重,采用有源电力滤波器补偿谐波是一个重要的发展趋势。其基本原理是检测出补偿对象中谐波电流的大小,再由有源电力滤波器产生一个与谐波电流大小相等、极性相反的补偿电流来净化电网电流使其仅含有基波分量。这种滤波器能对频率和幅值都变化的谐波进行跟踪补偿,补偿特性也不受电网阻抗的影响,因而受到广泛的重视。本文就单周控制在有源电力滤波器中的应用进行了研究,主要内容如下: 选取基于瞬时无功功率理论的法作为有源电力滤波器的谐波电流检测方法,三角波调制法和滞环控制法作为有源电力滤波器的电流跟踪控制电路,对三相有源电力滤波器在电源电压对称的情况进行了仿真,并与单周控制的三相三线制有源电力滤波器在电源电压对称时的仿真结果进行了比较分析,针对其出现的不足,本文首次提出了基于检测法和单周控制的有源电力滤波器,本文在推导其控制的关键方程后,建立了基于法和单周控制的有源电力滤波器的电路模型,并在电源电压对称的情况对其进行了补偿谐波、补偿无功、同时补偿谐波和无功三种情况的仿真,在电源电压不对称时对其补偿谐波的情况进行了仿真,并与单周控制的三相三线制有源电力滤波器在电源电压不对称时的仿真结果进行了比较分析,仿真结果表明有源电力滤波器在实现其多功能性的同时又能具有简单的结构、较高的控制精度、快速的响应速度,与理论分析一致,而且在三相电源电压不对称的情况下,补偿后使三相电源电流与三相电源电压成正比,三相电源电流基本达到对称。本文首次提出将通用常频积分(UCI)控制的矢量模式应用于三相四线制有源电力滤波器,在分析UCI控制四桥臂三相四线制APF的开关周期平均模型的基础上,推导出UCI控制的关键方程,建立了UCI控制的电路模型,并对四桥臂的三相四线制有源电力滤波器进行了仿真研究,这种方法相对于单周控制减少了工作于高频的开关数量,从而降低了开关损耗。更多还原

【Abstract】 As harmonic contamination increasingly severity, so the introduction of active power filter (APF) is an important development trend. As far as principles of APF are concerned, harmonic currents of compensated target are detected first, then APF generates compensating currents which are equal to harmonic currents in amplitude and converse in polarity to purify power currents. After compensation, the power currents only contain fundamental components. When frequency and amplitude of harmonic currents vary, this kind of filter can compensate harmonics effectively. Moreover, the compensation performance is not affected by power impedance. So, it is more and more acceptable. This studies applications of one –cycle control in APF. The main contents are as follows:The method based on instantaneous reactive power theory is used as harmonic currents detecting method of APF, triangular wave modulation method and hysteresis control method are applied to currents tracing control circuit of APF. And simulations of three-phase APF are performed under symmetrical power source voltage condition. Furthermore, comparison is drawn between above simulations and simulations of three-phase three-wire APF with one-cycle control under symmetrical power source voltage condition. In order to solve its disadvantages, this thesis presents a APF based on both detecting method and one-cycle control for the first time. The key control equations are derived and model of APF is set up. Simulations are carried out under symmetrical power source voltage for harmonic compensation, reactive power compensation, and both harmonic compensation and reactive power compensation respectively. In addition, simulations for harmonic compensation are performed under asymmetrical power source voltage condition as well. And comparison is drawn between the above simulations and simulations of three-phase three-wire APF with one-cycle control under asymmetrical power source voltage condition. The simulation results verify APF presented in this thesis not only achieves multi-function, but also acquires simple structure, high control accuracy and fast response speed. Moreover, under symmetrical power source voltage condition, three-phase power source current are proportional to three-phase power source voltage after compensation and almost symmetrical.This thesis applies vector operation of Unified Constant Frequency Integration(UCI)control to three-phase four-wire APF for the first time. Based on the analysis of UCI controlled four-arm three-phase four-wire APF, and simulations are performed. By <WP=6>comparison with one-cycle control, this scheme decreases switches operating at high frequency and reduces switching losses.更多还原