电网不平衡下变换器电流指令计算新方法  

A New Method for Calculating the Current Instruction of Converter Under Unbalanced Grid

作　　者：尤赟[1] 宋中仓[1] 

机构地区：[1]江苏自动化研究所,江苏连云港222061

出　　处：《电力电子技术》2017年第6期71-74,共4页Power Electronics

摘　　要：电网不平衡条件下运行的三相电压源型变换器(VSC),由于负序电压分量的影响,变换器交流电流和直流母线电压会出现非特征次谐波,可能危害电网及附近用电设备的正常运行。针对上述问题,以如何抑制直流母线电压的谐波为研究目标,首先在两相静止α,β坐标系下分析了三相VSC的瞬时功率模型,在此基础上提出一种新的电网不平衡情况下交换器参考电流指令的计算方法。该方法无需复杂的坐标变换和控制变量的正负序分离,简化了不平衡情况下VSC的控制。最后,通过仿真和实验验证了该方法的可行性。When three-phase voltage source converters（VSC） operates in three-phase unbalanced grid conditions, due to the negative sequence voltage, non-characteristic harmonics will generate in the alternating current and direct current link voltage,which may endanger the normal operation of the power grid and nearby electrical equipment.For these problems,how to suppress the harmonic of the DC bus voltage is treated as the research target.Firstly,the instanta- neous power of VSC is analysed in the two-phase stationary α,β frame.Based on the analysis above,a new method to calculate the reference current instruction is proposed, without complicated rotation transformation and sequential com- ponent extraction of the input voltages,which simplifies VSC control under the unbalanced gird condition.Finally, the feasibility of the control method is verified by simulation and experimental results.

关 键 词：变换器 电网不平衡 电流指令 

分 类 号：TM46[电气工程—电器]