三相VIENNA整流器双闭环控制策略及其参数研究

通过对VIENNA整流器基本原理分析,建立了d-q坐标系下的数学模型。由于系统具有强耦合、非线性的特点,利用前馈解耦控制策略实现对d、q轴的解耦控制。一方面,基于频域法对电流内环进行分析,借助MATLAB单输入-单输出SISO(single input-single output)设计工具,合理配置电流内环控制器零点位置与环路增益,实现对网侧电流快速性与稳定性的控制;另一方面,电压外环易受到负载电流影响,通过对外环控制器零点和环路增益优化配置,提高系统鲁棒性。此外,重点分析了在负载电流干扰的情况下影响电压外环控制器稳定性的成因。最后,利用MATLAB/Simulink软件搭建仿真平台,验证了电流内环和电压外环控制器参数设计的正确性与合理性,使VIENNNA整流器双闭环控制系统具有良好的稳定性能和动态性能,并在负载波动的情况下,保持良好的控制效果。

Dual Closed-loop Control Strategy and Parameter Design for Three-phase VIENNA Rectifier

Through the analysis of the fundamental principle for a VIENNA rectifier, a mathematical model in d-q reference frame is proposed. Due to system characteristics, such as strong coupling and nonlinearity, the decoupling control of d-q frame is realized by means of the feed-forward decoupling control strategy. On one hand, inner current loop is analyzed based on the frequency-domain method, and the zero position and loop gain of inner current loop controller is reasonably configured with the single input-single output(SISO) design tool in MATLAB, thus realizing the co-ntrol of rapidity and stability for grid current. On the other hand, in consideration of the effect of load current disturbance on outer voltage loop, the system robustness is improved by configuring the zero position and loop gain of outer loop controller. In addition, under the condition of load current disturbance, the factors that influence the stability of outer voltage controller are analyzed especially. Finally, a simulation platform was constructed using MATLAB/Simulink, and results demonstrated the correctness and reasonability of parameter design for inner current loop controller and outer voltage loop controller. In this way, the dual closed-loop control system for the VIENNA rectifier can realize excellent stability and dynamic performance, and maintain a satisfying control effect in a wide range of load.