基于系统辨识RLS算法的PWM变换器小信号建模  

Small-Signal Modeling of PWM Switching Converter Based on Recursive-Least-Squares Algorithm of System Identification

作　　者：杨杰[1] 鄢登高[1] 师宇杰[1] 

机构地区：[1]信息工程大学信息工程学院,郑州450002

出　　处：《系统仿真学报》2013年第7期1460-1464,共5页Journal of System Simulation

摘　　要：提出一种利用时域仿真数据来建立脉宽调制(PWM)开关变换器小信号模型的新方法。这种利用仿真软件PSpice和MATLAB所得到的数据基于黑箱理论来辨识PWM开关变换器系统的方法是较为简便和独特的。首先推导出PWM开关变换器的离散小信号线性等效模型,然后将开关变换器看做一个黑箱模型,利用电路仿真软件PSpice仿真得到的阶跃响应数据,采用系统辨识的递推最小二乘参数估计的方法来拟合阶跃响应曲线,得到开关变换器的离散時不变小信号模型,利用零阶保持器将此离散系统连续化,最终得到PWM开关变换器的连续小信号模型(控制—输出传递函数)。采用此方法对BUCK变换器和有源箝位倍压变换器(ACPDC)进行建模,并将所建模型与状态空间平均建模方法进行比较,验证了此建模方法的准确性。A new modeling method for pulse width modulation （PWM） switch converter by using the data througha time-domain simulation was proposed. This system identification method based on the black-box approach using the data from well-known design tools such as PSpice and MATLAB is simpler and independent of PWM switch converter. The discrete-time small-signal linear equivalent models for PWM converter was deduced first. Then the method regarded switch power converter as a black box, only with the PSpise simulation input and output data of switch power converter by using the Recursive-least- squares parameter estimation algorithm of system identification to fit the step response curve for modeling. The small signal modeling （Control-to-Output transfer function） was generated. The model of BUCK converter and Active Clamping Push-Pull Dual voltage Converter were built using the method. Compared with the model for the state-space averaging method, the accuracy of the method was proved.

关 键 词：系统辨识 黑箱理论 RLS 阶跃响应曲线 小信号建模 变换器 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]