单相三电平整流器d-q坐标系下的控制与SVPWM方法

摘要

为了减弱高速动车组与牵引供电网压之间的相互耦合关系,以电力牵引变流器中的单相三电平中点钳位(NPC)整流器为对象,分析了其工作原理,建立了其在d-q坐标系下基于开关函数的数学模型;然后给出了一种基于d-q变换的有功无功电流控制算法.并在此基础上,提出了一种单相三电平空间矢量调制( SVPWM)方法.与传统的正弦脉宽调制方法相比,该调制方法不但能够有效地降低牵引变压器的绝缘等级和电压突变的耐受能力,并且还具备中点电位控制能力.最后,计算机仿真和小功率样机实验验证了该控制方法和调制方法的有效性和可行性.%In order to reduce the coupling influence between high-speed electric multiple units (EMU) and the voltage of traction power gird, the operation principle of single-phase three-level neutral point clamped (NPC) rectifier in electrical traction converter was analyzed firstly, and the mathematic modeling in d-q reference frame was described. Then an active and reactive current decoupled control scheme in d-q synchronous frame was presented. On the basis of this, a single-phase three-level space voltage pulse width modulation (SVPWM) was proposed. Compared with the traditional sine pulse width modulation ( SPWM) , the adopted SVPWM method can not only reduce the requirement of insulation grade and voltage jump impulse durability for the traction transformer, but also balance neutral point voltage effectively. Finally, the validity and feasibility of the control and modulation scheme are verified by computer imulation and a low power prototype experiment.