State Grid Corporation of China

State Grid Jiangsu Electric Power Company

State Grid Jiangsu Electric Power Co., Ltd. Marketing Center

State Grid Jiangsu Economic Research Institute

State Grid Jiangsu Electric Power Design Consulting Institute Co., Ltd.

State Grid Jiangsu Electric Power Co., Ltd. Economic Research Institute

Wanchun Qi

Chen Li

Zheng Xu

Hui Cai

Zhenjian Xie

Quanquan Wang

Wenjia Zhang

Jian Yang

Ming Yan

Boliang Liu

Chen Wu

Zhuyi Peng

Feifei Zhao

Wentao Sun

Xingning Han

Caixuan Xu

Chengchen Huang

Zheren Zhang

Provided is a control method for a parallel MMC unit of a LCC-MMC hybrid cascade converter station. The control strategy includes: 1) numbering all MMC units connected in parallel in a MMC valve manifold; (2) for a MMC unit using a constant direct-current voltage control manner, calculating a direct-current instruction value of the MMC unit according to a direct-current measurement value; (3) for a MMC unit using a constant active power control manner, calculating an active power instruction value of the MMC unit according to the rated capacity of the MMC unit and a direct-current instruction value of a system rectifier station; (4) for the MMC unit using the constant direct-current voltage control manner, correcting a direct-current voltage instruction value of the MMC unit by using the direct-current instruction value and the direct-current measurement value, and controlling the MMC unit according to the corrected direct-current voltage instruction value.

Control method for a parallel MMC unit of a LCC-MMC hybrid cascade converter station

A general load flow calculation method for power systems with unified power flow controller (UPFC). On the premise of satisfying the control objectives of UPFC, the calculation method combines the power injection model with the Newton-Raphson algorithm to solve the load flow of the power systems by iteration. It is applicable not only to a conventional UPFC structure, but also to a novel UPFC structure wherein the series and shunt transformers of a UPFC are connected to different AC buses or there are more than one series branch connected to a UPFC. The present invention provides the detailed process for performing a load flow evaluation, and it shows that it is unnecessary to add new state variables when solving the load flow by this method, the dimension of the Jacobian matrix will not increase during the iteration.

General load flow calculation method for power systems with unified power flow controller

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Nanjing, China

Wanchun Qi