直驱永磁风力发电系统低电压穿越改进控制策略研究  

Improved control theory for low voltage ride-through of permanent magnet synchronous generator

作　　者：李戈[1,2] 宋新甫[3] 常喜强[3] 

机构地区：[1]西安理工大学,陕西西安710048 [2]陕西省电力公司延安供电局,陕西西安710048 [3]新疆电力公司,新疆乌鲁木齐830011

出　　处：《电力系统保护与控制》2011年第12期74-78,83,共6页Power System Protection and Control

摘　　要：采用改进的瞬时对称分量法对电网电压瞬时值进行对称分量分解,提出了电网电压不对称跌落时D-PMSG的低电压穿越控制策略。按照电网电压正序分量和额定电压的比值减小发电机功率,并在解耦控制中分别控制正序和负序分量,正序通道完成能量的传输,负序通道产生和电网负序电压相等的负序电压,从而保证网侧逆变器电流中无负序分量,避免了逆变器非全相过负荷,充分利用其容量。仿真结果研究表明,提出的改进控制策略实现了不对称故障下的低电压穿越,并且保持了逆变器三相电流对称。An improved instantaneous symmetrical components method is applied to detect the positive sequence,negative sequence and zero sequence components of grid voltage sag,then the control method for low voltage ride-through of permanent magnet synchronous generator when grid voltage asymmetrical sags is put forward.The power of PMSG is reduced according to the ratio of grid positive sequence component and rated voltage during voltage dip.The positive and negative sequence components are controlled through respective channel.The power is transmitted in positive sequence channel while negative sequence voltage,which is equal to grid negative sequence voltage,is produced in negative sequence channel.So the inverter current does not contain negative sequence component,avoid the open-phase overload inverter,and make full use of its capacity.Simulation results show that the improved control strategy realizes LVRT in condition of asymmetrical fault and keeps symmetry of inverter three phase current.

关 键 词：直驱永磁同步风力发电机组 低电压穿越 不对称电网电压 瞬时对称分量法 

分 类 号：TM315[电气工程—电机]