JIN Yangxin, XV Xidong, ZHOU Jingen

(College of Electrical Engineering, Zhejiang University, Hangzhou  310027， China）

 

 

Abstract: Aiming at the issue that the voltage drop caused by the reasons like impact load affects the stability of DC distribution, VSC operation limitation and maximum output capacity under different operation circumstances were analyzed in DC distribution; and then a new AC current limitation segment was proposed between the inner and outer loop of local control, which ensures VSC transmit the maximum power via limiting the current reference of current inner control even in the case of significant DC voltage drop, so as to promote the recovery of DC voltage. Finally the validity of the proposed current limitation segment was verified with PSCAD/EMTDC digital time domain simulation software. The results indicate that the current limitation segment can prescribe a reasonable limit to the current reference, and guarantee the maximum power transmission during substantial DC voltage drop, which benefits the voltage stability of DC distribution.

Key words: DC distribution; current limitation control; transient DC voltage stability