Investigation of a power network quality comprehensive control device based on novel cascaded power units

Power quality control device can solve most problems in power grid. However, there are still many problems with traditional single‐function power quality control devices, such as enormous capital investment, high operational costs, difficulty in coordination of control, and failure to achieve a technical and economic optimization. This article proposes a power quality comprehensive control device with a new topological structure and control method. It can provide a new level of comprehensive power quality control in medium‐voltage and high‐capacity applications. Firstly, the topology and working principle of the novel comprehensive power quality control device based on cascaded H‐bridge converter are analyzed, and the key parameters of the device are designed in detail. Secondly, a multi‐functional coordinated control strategy is proposed to control the power quality comprehensive control device. Both the accuracy of parameter and the effectiveness of coordinated control strategy are validated by MATLAB/Simulink simulation results. Finally, a power quality comprehensive control device with 10 kV/1MVA was developed. The experimental results show that the device can achieve power quality comprehensive control functions for 10 kV distribution network, including voltage sag, flicker, harmonics, phase imbalance, and frequency deviation. In this article, a novel power unit consisting of cascaded H‐bridge convertor and storage battery was used as the basic link, and a comprehensive power quality control device was constructed.