离散时间模型预测控制在光伏并网中的研究

摘要

According to the characteristics of photovoltaic grid-connected inverter, a mathematical model of the network system was established, and a SVPWM discrete time-based model predictive control (MPC) was proposed for Photovoltaic Grid and a new cost function. Within each sampling period, according to the model of predictive control, three-phase grid-connected inverter voltage vector was filtered to get the minimum value function of voltage vector, and the prediction algorithm to calculate the voltage vector of the next sampling period in the role of time. Traditional hysteresis control and discrete-time model to predict the photovoltaic grid were simulated in Matlab/simulink, it was verified that the MPC-based photovoltaic grid had better dynamic and static characteristics, grid-side harmonics to achieve d-axis current and q-axis current decoupling control of photovoltaic grid.%针对光伏并网逆变器的工作特性，提出了一种基于SVPWM离散时间模型预测控制(MPC)的光伏并网，构建了一个新型的价值函数，建立了光伏并网系统数学模型。在每个采样周期内，根据预测控制模型，对三相并网逆变器的8个电压矢量进行筛选，得到使价值函数最小的电压矢量，并根据预测算法，计算出电压矢量在下一个采样周期中所作用的时间。通过Matlab/simulink分别对传统的滞环控制以及离散时间模型预测的光伏并网进行了仿真，验证了基于MPC的光伏并网具有更好的动态、静态特性，并网网侧谐波小，实现了d轴电流以及q轴电流的解耦控制，对光伏并网具有一定的意义。