Open AccessStart Control for the MMC-HVDC
Author(s) -
Xiaoliang Zhang,
Lipeng Ning,
Yanjiao Yin,
Boyang Zhao,
Jingwen Han,
Fangkai Hu
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/486/1/012005
Subject(s) - capacitor , resistor , limit (mathematics) , control theory (sociology) , power (physics) , voltage , control (management) , engineering , stage (stratigraphy) , power factor , ac power , electrical engineering , computer science , mathematics , physics , mathematical analysis , paleontology , quantum mechanics , artificial intelligence , biology
This paper designs the control strategies and start procedure of MMC-HVDC. The start procedure consists of three stages, uncontrollable charging stage, controllable charging stage and power-raising stage. The current circuit is analysed and the equivalent circuit is obtained in uncontrolled charging stage. The computational formula of current-limit resistor is obtained in the uncontrollable stage. Two different control strategies to further charge the capacitors to the rated voltage in controllable charging stage are designed. Strategy one makes use of DC voltage control and balancing strategy of capacitor voltage while Strategy two divides the capacitors of one arm into two groups. In power-raising stage, to avoid the impact of power step, slope control is used in power outer loop. Finally, a simulation model is established in the PSCAD/EMTDC. The simulation results show that the effectiveness and rationality of the designed start procedure and control strategies