模型预测控制三相并网变换器的研究

摘要

在新能源发电领域，三相电压源型并网变换器的应用越来越广泛。为了提高并网性能，国内外的学者们提出了各种新型的并网控制策略。模型预测控制策略利用系统的离散时间模型来预测所有可能的电压矢量下系统下一个采样时刻的输出值，通过评估函数选择出最优的电压矢量。以传统的三相电压源型变换器为控制对象，提出了一种基于模型预测控制的三相电压源型并网变换器的控制方法。采用DSP28335作为控制器，设计了三相电压源型并网变换器的实验平台，分析讨论了并网电流的稳态与动态性能以及进行无功功率补偿时并网电流的稳态性能。实验结果验证了模型预测控制在三相并网变换领域的优越性。%In recent years, three-phase grid-connected converters are becoming more and more popular in the field of renewable energy. In order to improve the grid performance of renewable energy generation systems, a variety of new grid-connected control strategies have been proposed. Model predictive control method uses a discrete-time model of the system to predict the future value of the load current for all possible voltage vectors generated by the converter. The voltage vector which minimizes a cost function is selected and used at the next sampling instant. This paper presents a model predictive current control algorithm for power converters based on a three-phase grid-connected voltage source converter. A TMS320F28335 floating-point DSP is used for the experimental platform. The steady-state and dynamic performance of the grid-connected current is investigated with the compensation in the reactive power. Simulation and experimental results validate the superiority in three-phase grid-connected area of the proposed model predictive control method.