直驱式波浪发电系统的经济模型预测控制

Economic model predictive control of direct-drive wave power generation systems

对于随机海浪环境下的最大功率捕获,现有控制方法没有考虑系统模型的非线性、损耗及物理约束等条件,基于经济模型预测控制,提出一种波浪发电系统功率优化方案。采用普罗尼线谱估计方法拟合海浪辐射力,基于水动力方程和电机状态方程建立波浪发电系统数学模型。在考虑电机功率损耗条件下,以最大波能捕获为经济指标,求解符合系统约束的最优电磁力。采用电流矢量和空间脉宽调制策略实现最大波能捕获控制。仿真结果表明,所提方案响应速度快,鲁棒性强,可使波浪能转换装置运行在合理范围,波浪能利用率提高,机体劳损减小。

For the maximum power capture in a random wave environment,the nonlinearity,losses,and physical constraints of the system model are not considered in the existing control methods.Based on the economic model predictive control,a power optimization scheme for wave power generation systems is proposed in this paper.The radioactive force of waves was fitted using the Prony spectrum estimation method,and a mathematical model of wave power generation systems was established based on the hydrodynamic equation and the equation of the machine state.Taking the power loss of the machine into consideration,the maximum power capture is taken as the economic indicators,and the optimal electromagnetic force that meets system constraints is solved.The current vector and space pulse width modulation strategies are used to achieve the maximum power capture control.The simulation results show that the proposed scheme has fast response speed and strong robustness,which can make wave energy converters operate in a reasonable range,improve the wave energy utilization rate,and reduce the body strain.