实现同相补偿的三相变流器输出滤波器LCL参数设计

针对同相供电系统中存在高次谐波问题,提出以电网侧电流谐波畸变率(Total Harmonic Distortion,THD)最小为目标的输出滤波器LCL参数设计方法。首先从机车电流、网侧电感、同相补偿装置(Co-phase Compensation Device,CPD)输出电流整体角度出发,推导电网侧谐波畸变率THD和CPD谐波衰减比RAF (Ripple Attenuation Factor)与网侧电感、LCL电容、LCL总电感、LCL总电感分配比之间的关系。其次以CPD补偿电流满足快速跟踪性、开关纹波电流满足抑制要求、LCL基波无功损耗满足限制条件来确定参数取值范围。THD最小为目标函数,RAF为约束,应用分割矩形算法(Dividing Rectangle Algorithm,DIRECT)进行求解,得到THD值最小时LCL滤波器的参数值。最后利用MATLAB/simulink仿真验证参数设计的正确性。

Parameter Design of Three-phase Converter LCL Output Filter for Co-phase Power Supply Compensation

To solve the problem of high frequency harmonics in the co-phase power supply system,San output filter LCL parameter design method which aims at the minimum THD (total harmonics distortion, THD) of grid side current is proposed.SFirst,Sfrom the overall perspective of locomotive current, grid side inductance,SandSoutput current from co-phase compensation device(CPD),Sthe paper deduces the relationship among THD of grid side current and RAF (ripple attenuation factor,SRAF) of CPD,Sthe grid side inductance,Sthe capacitance of LCL,Sthe total inductance of LCL,Sand the total inductance distribution ratio of LCL. Then,Sthe range of parameter value is determined by making CPD compensation current meet fast tracking ability,Sswitching ripple current meet the inhibition requirement,Sand LCL fundamental reactive power loss meet the restriction conditions.SThe minimum THD is the objective function and RAF is the constraint.SThe dividing rectangle algorithm is applied to solve the problem and find the parameter value of LCL with the minimum THD.S Finally, the accuracy of the parameter design is verified by MATLAB/simulink.