非理想条件下并联有源电力滤波器的无源超螺旋二阶滑模控制策略

Passive Super-twisting Second-order Sliding Mode Control Strategy for SAPF Under Non-ideal Conditions

电力系统运行在非理想状态时,容易产生短暂的电压波动,此时并联有源电力滤波器(shunt active power filter,SAPF)采用无源控制策略无法高效、精确地调节电能质量,而常规滑模控制又容易引起抖振。针对上述情况,将无源控制和抗干扰能力更强的超螺旋二阶滑模控制相结合,提出了一种无源超螺旋二阶滑模控制策略。首先,根据有源电力滤波器的数学模型建立基于正负序分离的欧拉−拉格朗日模型;其次,对系统的模型进行了无源性分析,且根据其无源性设计了无源控制器,同时采用超螺旋二阶滑模控制对无源控制器进一步优化,提高了系统整体的鲁棒性和抗干扰能力;最后,在理想状态和负载突变、负载不平衡、电网电压不平衡、单相电压突变4种非理想状态下,通过仿真实验验证了无源超螺旋二阶滑模控制策略的有效性和优越性。

When the power system operates under non-ideal conditions,significant voltage fluctuations occur.The utilizatuion of a passivity-based control strategy in the shunt active power filter(SAPF)may not effectively and accurately regulate power quality.Besides,conventional sliding mode control is also prone to buffeting.In the light of this,a passive super-twisting second-order sliding mode control strategy is proposed in this paper,which is a combination of passivity-based control and super-twisting second-order sliding mode control with stronger resisting disturbance capacity.First of all,the Euler-Lagrange model is established based on positive and negative sequence separation,in accordance with the mathematical model of active power filter.Secondly,the passivity of model is analyzed,and a passivity-based controller is designed according to its passiveness.Meanwhile,the passivity-based controller is further optimized by using the super-twisting second-order sliding mode control,thereby enhancing the robustness and capacity of resisting disturbance.Finally,simulation experiments are carried out under both ideal condition and four nonideal conditions,namely load mutation,load imbalance,grid voltage imbalance and single-phase voltage mutation.The simulation results verify the effectiveness and superiority of the passive super-twisting second-order sliding mode control strategy.