基于混杂系统DC-DC变换器的永磁风电并网系统直流母线电压稳定控制

为了提高基于固态变压器的永磁风电并网系统中直流母线电压的稳定性，在低压直流侧，通过双向DC-DC加入超级电容器。文章基于Boost电路建立混杂系统模型，引入类滑模控制策略，利用超级电容器的快速充放电特性，提高直流电压的稳定性。仿真研究表明，在风速改变和电网电压跌落两种工况下，直流侧电压波动、超级电容器充放电电压和充放电电流均变小。该方案可以快速准确地抑制直流母线电压波动，改善并网风力发电机组的电能质量和稳定性。

DC Bus Voltage Stability Control of DC-DC Converter in the Permanent Magnet Wind Power Grid-Connected System Based on the Hybrid System

In order to improve the stability of the DC-bus voltage in the permanent magnet wind power integrated system based on the solid-state transformer, the super capacitor is utilized through the bi-directional converter at the low voltage DC side. This paper models the hybrid system of the Boost circuit with the sliding mode control, and the stability of the DC voltage is improved by the quickly charge-discharge characteristics of the super capacitor. The simulations demonstrate that voltage fluctuation in the DC side and the charge-discharge voltage and current of the super capacitor become smaller under the conditions of both wind speed change and grid voltage drop. This scheme rapidly and accurately suppresses the fluctuation of the DC-bus voltage and improves the power quality and stability of the grid wind turbines.