摘要
大规模风电经固定串补线路送出时,双馈风电机组(DFIG)会由于转子侧换流器(RSC)与固定串补之间相互作用而引起一种新的次同步振荡问题,称为次同步控制相互作用(SSCI)。在分析DFIG换流器的工作原理及输出特性的基础上,建立其基于交流受控电压源和直流受控电流源的等效仿真模型,避免了开关器件的高次谐波对DFIG电气阻尼计算结果的影响,提高了仿真效率。基于等效模型,采用时域实现的复转矩系数法,计算DFIG在次同步频率范围内的电气阻尼特性,进而分析风速、转子侧换流器PI参数、串补度和线路电阻对电气阻尼特性的影响。分析结果表明,风速的减小、内环增益的增大、积分时间常数的减小、串补度的增加以及线路电阻的减小都会增加DFIG电气负阻尼;外环PI参数对DFIG阻尼特性影响不大。提出在DFIG RSC中附加混合次同步阻尼控制器(H-SSDC)来抑制SSCI的方法,仿真结果验证了其有效性。
SSCI（Sub-Synchronous Control Interaction）,a new type of sub-synchronous oscillation,may induced by the interaction between the rotor side converter and the compensating capacitor of DFIG（Doubly-Fed Induction Generator） when large-scale wind power is transferred through the transmission lines with fixed series compensation. The working principle of DFIG converter and its output characteristics are analyzed and its equivalent simulation model based on the controlled voltage source at AC side and the controlled current source at DC side is built,which avoids the impact of high-order harmonics of switching devices on the calculative results of DFIG electrical damping to enhance the simulation efficiency. Based on the equivalent model,the complex torque coefficient method is adopted in time-domain to calculate the electrical damping characteristics of DFIG within the range of sub-synchronous frequency for analyzing the impacts of wind-speed,converter PI parameters,compensation-degree and transmission line resistance on the electrical damping characteristics. The analytical results show that,the negative electrical damping of DFIG increases along with the wind-speed decrease,inner-loop gain increase,integral time-constant decrease,compensation-degree increase and transmission line resistance decrease;the impact of outer-loop PI parameters on the damping characteristics of DFIG is not large. An additional H- SSDC（ Hybrid Sub-Synchronous Damping Controller） in the rotor side converter of DFIG is proposed to restrain SSCI and its effectiveness is verified by the simulative results.
出处
《电力自动化设备》
EI
CSCD
北大核心
2015年第12期11-20,共10页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51507064)
中央高校基本科研业务费专项资金资助项目(2015MS84)~~
关键词
双馈风电机组
次同步控制互作用
模型
复转矩系数法
混合次同步阻尼控制器
风电
阻尼
doubly-fed induction generator
sub-synchronous control interaction
models
complex torque coefficient method
hybrid sub-synchronous damping controller
wind power
damping
