提高送端多直流落点系统暂态稳定性的L_2增益控制

An L_2 Gain Disturbance Attenuation Control Approach to Improve Transient Stability of HVDC Power Transmission System With Multi Feed-Terminals at Sending End

提出了一种改善送端多直流落点系统暂态稳定性的L2增益控制。首先将送端直流线路传送的有功功率简化为送端系统的正的有功负荷,构造送端多直流落点系统非线性微分代数方程模型;然后采用预置反馈的方法,得到包含多条直流线路的结构保持模型的拟哈密尔顿实现;最后基于拟哈密尔顿实现,针对系统外界干扰,通过非线性干扰抑制方法,得到高压直流与发电机励磁的控制规律,使得系统的干扰量到输出量的L2增益低于给定的水平。仿真结果表明,与传统控制器比较,所设计的控制器能够保证系统的渐进稳定性,有效抑制干扰,具有较强的鲁棒性。

An L2 gain disturbance attenuation control approach to improve transient stability of HVDC power transmission system with multi feed-terminals at sending end is proposed. Firstly, the active power transmitted by DC lines at sending end is simplified as positive active load of sending end to construct nonlinear differential algebraic model of multi DC feed-terminal system at sending end; then using pre-feedback, the quasi Hamiltonian realization of the structure preserving model containing multi DC lines is obtained; finally, through nonlinear disturbance attenuation the control laws of HVDC system and generator excitation are obtained to make the L2 gain from system disturbance to output lower than given level. Simulation results show that the designed controller can ensure better asymptotic stability than traditional controller; besides, it can restrain disturbance effectively and possesses stronger robustness.