为了抑制变电站中由电压互感器引起的铁磁混沌振荡问题,提出了一种异结构同步的非线性反馈控制方法设计控制器。该方法构造了一个正定的李雅普诺夫函数,使其随时间的导数定负,并将基于李雅普诺夫函数构造的控制器外加在状态方程中,选择状态变量磁链为输出信号,并使该输出信号追踪正弦参考信号,要求误差信号趋于零值。为使控制信号在实际中易于提取,在控制器中用电流替换磁链进行改进。数值仿真结果表明,加入控制器后,系统输出磁链(标幺值)由5降到近似1,电压(标幺值)由17的非周期过电压降到近似1的正弦稳态值。改进控制器后的系统输出电压也由非周期过电压过渡为周期性正弦电压,且电压幅值大大降低,研究结果证明了该控制方法的有效性。
To suppress the ferromagnetic chaotic oscillation from voltage transformer in substations,a nonlinear feedback control strategy with different structure synchronization is proposed to design the controller.A positive definite Lyapunov function with negative definite derivative over time is constructed,and the tentative controller takes part in the state equation,where the flux serves as the output signal to track sinusoidal reference signal to keep error signal as zero.For the purpose of easy extracting,the current is chosen instead of the flux.The numeric simulation shows that once adding the controller,the system flux decreases from 5p.u.to 1p.u.,and voltage decreases from non-periodic overvoltage of 17 p.u.to steady sinusoidal value of 1 p.u.,and the previous non-periodic overvoltage output can be transformed into periodic sinusoidal voltage with greatly reduced amplitude.