Vienna整流器改进无差拍混合控制策略研

Study on Improved Deadbeat Hybrid Control Strategy for Vienna Rectifier

三相Vienna整流器发生负载突变时,将导致直流侧输出电压波动。针对此问题,提出一种基于线性自抗扰控制的改进无差拍混合控制策略。首先,在建立三相Vienna整流器数学模型的基础上,电流内环引入改进无差拍控制算法,将预测电流推迟至k+2时刻,以此来消除网侧电流谐波,实现对网侧电流的精准跟踪控制,使系统网侧电流总谐波畸变率由4.33%降至2.06%。其次,电压外环引入线性自抗扰控制,将模型参数变化作为系统内部扰动,通过LESO实时估计扰动并补偿,解决了负载突变工况下直流侧输出电压波动过大的问题。最后,搭建Vienna整流器仿真模型以及10 kW试验样机对所提混合控制策略进行验证。仿真与试验结果表明,所提混合控制策略在系统带载启动、负载变化等场景具有较好的稳态、动态性能。

When the load of the three-phase Vienna rectifier changes abruptly,the output voltage of the DC side will fluctuate.An improved beat free hybrid control strategy based on linear active disturbance rejection control is proposed.First,based on the mathematical model of the three-phase Vienna rectifier,an improved beat free control algorithm is introduced into the current inner loop to postpone the predicted current to k+2,so as to eliminate the current harmonics on the network side and achieve accurate tracking and control of the current on the network side,reduce the total harmonic distortion rate of system grid-side current from 4.33%to 2.06%.Secondly,linear active disturbance rejection control is introduced into the voltage outer loop,and the model parameter change is regarded as the internal disturbance of the system,and the disturbance is estimated and compensated by LESO in real time,which solves the problem of excessive DC output voltage fluctuation under the load sudden change condition.Finally,the proposed hybrid control strategy is verified by building a simulation model of Vienna rectifier and a 10 kW experimental prototype.The simulation and experimental results show that the proposed hybrid control strategy has better steady state and dynamic performance in the scenarios of system start-up with load and load change.