基于dq变换的三相VSR的研究

Research on Three-Phase VSR Based on dq Transform

建立了基于d-q同步旋转坐标系下的三相电压型PWM整流器(VSR)解耦状态方程,给出了双闭环控制策略,即电流内环实现指令电流跟踪控制,电压外环实现稳压输出。在此基础上,文中提出了SVPWM快速算法,完成了指令电压矢量所在扇区的判断和不同扇区PWM调制波占空比计算方法,避免了非线性运算,提高了运算速度和计算精度。最后,在MATLAB/SIMULINK环境下建立了系统的仿真模型,并进行了实验样机的研制,仿真和实验结果表明:所设计的三相PWM整流器实现了单位功率因数运行,输入电流谐波含量低,输出直流电压稳定。

The decoupled state-space equations of three-phase voltage-source PWM rectifier in synchronous rotating reference flame （d-q frame） is established first. The double-closed-loop control strategy is adopted, which means the inner current-loop tracks reference current and the outer voltage-loop keeps the output voltage constant. A simplified algorithm is proposed, which simplifies the determination of the sector for reference voltage vector and calculation of the duty ratio in different sectors and avoids the nonlinear operations and improves the calculation speed and accuracy. Finally, The whole system is simulated using the toolbox of Matlab/Simulink and realized in experiment. The results illustrate that three-phase PWM rectifier could achieve unity power factor, low harmonic and constant DC output.