【作者】 孔群；

【导师】 陈益广；

【作者基本信息】 天津大学 ， 电机与电器， 2006， 硕士

【摘要】 随着电力电子技术的飞速发展,越来越多的电力电子装置被广泛应用到各个领域,其中相当一部分负荷具有非线性或具有时变特性,使电网中暂态冲击、无功功率、高次谐波及三相不平衡问题日趋严重,给电网的供电质量造成严重的污染和损耗。因此,对电力系统进行谐波抑制和无功补偿,提高电网供电质量变得十分重要。电力有源滤波器(Active Power Filter,简称APF)与无源滤波器相比,APF具有高度可控制和快速响应特性,并且能跟踪补偿各次谐波、自动产生所需变化的无功功率和谐波功率,其特性不受系统影响,无谐波放大威胁。并联型电力有源滤波器(Shunt Active Power Filter,简称SAPF)更是得到了广泛的应用。近年来,自适应算法中的递推最小二乘法(简称RLS)应用越来越广泛,该算法简单,收敛速度快。应用基于RLS自适应算法的滤波器(简称RLS滤波器),可以快速有效的滤除杂波,同时自动调整滤波器参数,不断改进滤波性能,最终得到所需的信号。本文研究了基于平均功率和RLS自适应算法的并联型有源滤波器。它的参考电流是一个同电网相电压同相位的三相平衡的有功电流,它包含两个分量:一个是由实测的三相负载瞬时功率计算得到的,基于平均功率算法的电网应该为负载各相提供的有功电流瞬时参考值;另一个是为了维持有源滤波器中逆变器的直流母线电压基本恒定,主要通过RLS滤波器计算得出的电网各相应该提供的有功电流瞬时参考值。两个分量的计算共同构成了该有源滤波器参考电流的计算。补偿电流指令值与实际补偿电流比较生成控制逆变桥工作的PWM脉冲,生成补偿电流,达到补偿负载无功和抑制谐波的目的。应用RLS滤波器得到维持直流母线电压恒定的直流侧有功系数Ad c,克服了传统PI控制中参数难以得到且由于参数过于敏感而导致补偿后电流纹波太大的问题。使得当稳态时SAPF自身的功率损耗和暂态负载变化时因为直流侧电容提供电网和负载之间的有功功率差而引起的电压的波动迅速反馈到指令电流的计算中。RLS算法收敛快,SAPF实时性大大提高。基于该方法的SAPF结构简单,无需锁相器。根据本文的算法应用MATLAB建立了仿真系统,仿真结果表明基于该算法的SAPF的可行性和实时性。更多还原

【Abstract】 With the developing of electrical electronic technology, more and more equipments of this kind are used in every field. A big part of these equipments has the characters of nonlinear and time varying. Transient impact, reactive power, high order harmonic wave and unbalance three-phase load make more damage in electrical net. So compensating the reactive power and depressing the harmonic wave to raise the quality of power line becomes very important. Compared with Passive Power Filter (PPF), Active Power Filter (APF) has the higher controllable and faster response. APF can track and compensate every frequency harmonic wave, generate the reactive and harmonic wave power that needed for system automatically. These characters will not effect by system consist and will not magnify harmony wave. Shunt Active Power Filter (SAPF) is getting more application in APF.Recently RLS algorithm in self-adapting algorithm gets more and more application. RLS algorithm is very simple and convergence fast. By using RLS filter, we can filter noise very easy, adjust parameter automatically and promote the characters of RLS filter; finally get the signal we need.Designs a Shunt Active Power Filter and its reference current is a balance three-phase active current which has the same phase with voltage source. There are two parts including in the reference current value. One is the instantaneous active reference current which electrical system should give to the load based on average power. The other that gives by the PI controller is the instantaneous active reference current which electrical system should give to SAPF to maintain the DC-link voltage invariable. The control of second part is familiar to sliding mode control. Calculation of these two parts consist Average Power Algorithm. Controlled by the PWM pulse which get by comparing between the reference compensate current and real generating current, the inverter works to make there is only active current in the electrical system, compensate the reactive power and restrain the harmonic current.DC-line active parameter Adc which can remain DC-link voltage invariable get by using RLS filter overcome hard to get parameters and much ripple in compensation current of PI control. Construction of this kind SAPF is very simple and without phase lock loop device.Test results of simulation get by MATLAB demonstrate the availability and real-time characteristics of this SAPF.更多还原