双馈风电场次同步控制相互作用的分数阶滑模抑制策略

针对双馈风电场接入串补输电系统,提出一种可快速收敛的分数阶滑模控制策略以抑制次同步控制相互作用并增强控制系统鲁棒性。首先通过反馈线性化方法抵消双馈风电场固有的非线性;其次设计分数阶滑模控制策略并应用于网侧变流器控制回路,利用分数阶微积分算子所增加的自由度实现系统快速收敛;最后通过非线性时域仿真和实物仿真检验抑制效果。结果表明:所设计的分数阶滑模控制策略有效改善了次同步频率范围内的系统阻尼,能在不同工况下实现对次同步控制相互作用的有效抑制,使系统快速恢复稳定,并加强系统对参数摄动的鲁棒性。

Sub-synchronous Control Interaction Mitigation Strategy Based on Fractional-order Sliding Mode Control for DFIG-based Wind Farm

A fractional-order sliding mode control strategy was proposed for series-compensated doubly-fed induction generator(DFIG)-based wind farms to mitigate subsynchronous control interaction(SSCI) and enhance system robustness.Firstly,feedback linearization was used to cancel the inherent nonlinearities of DFIG-based wind farm.Secondly,fractional-order sliding mode control was designed and applied to the control loop of DFIG grid-side converter.The freedom provided by the fractional calculus operator was used to speeds up the convergence.Finally,nonlinear time-domain simulation and experiments were performed to evaluate the performance of the proposed control method.The results demonstrate that the designed fractional-order sliding mode control improves system damping and mitigates SSCI under varied operating conditions.The proposed control strategy also improves system robustness against parameter perturbation.