基于模型预测控制的VSC—HVDC自适应控制策略

Investigation of 8 VSC—HVDC adaptive control strategy based on the model prediction strategy

VSC-HVDC系统具有良好的自换相能力,可直接向无源网络和弱交流网络供电。提出一种基于有限控制集模型预测控制的VSC-HVDC系统逆变侧自适应控制策略,克服传统的双闭环控制存在的PI参数整定困难、动态响应能力差等问题,同时实现多控制目标及约束的逆变站自适应性控制。首先,推导VSC-HVDC系统在dq0坐标系下的离散数学模型,并据此给出逆变侧定交流电压控制的预测模型以及相应的多目标优化性能函数。接着,通过引入增量算子和反馈校正环节设计出改进后的多步模型预测控制策略,从而提高预测模型的参数鲁棒性。最后,通过对VSC-HVDC供电系统进行不同运行工况下的仿真对比分析,论证所提控制策略的可行性和有效性。

The VSC-HVDC system has a nice self commutated ability and can supply power to the passive network and weak AC network directly.In this paper,an adaptive control strategy is proposed for the inverter side of a VSC-HVDC system to overcome the problems of PI parameter tuning dificulties and the poor dynamic response of traditional double closed-loop control.Firstly,the mathematical model of the VSC-HVDC system in the dq0 coordi-nate system is deduced with a discrete format.The prediction model of AC voltage control on the inverter side and the corresponding multi obective optimization performance function are given.Then,the improved multi-step strategy of model predictive control is designed by introducing the an incremental operator and the feedback correction link,.which improves the parameter robustness of the prediction model.Finally,the VSC-HVDC power supplying system under different operating conditions is simulated to demonstrate the reliability and efficiency of the proposed control strategy.