HVDC transmission systems: Bipolar back-to-back diode clamped multilevel converter with fast optimum-predictive control and capacitor balancing strategy

详细信息    查看全文

• 作者：Miguel Chaves^a ; ^b ; ^{mchaves@deea.isel.ipl.pt"" rel=""nofollow} ; Elmano Margato^a ; ^b ; ^{efmargato@isel.ipl.pt"" rel=""nofollow} ; J. Fernando Silva^a ; ^c ; ^{fernandos@alfa.ist.utl.pt"" rel=""nofollow} ; Só ; nia F. Pinto^a ; ^c ; ^{soniafp@ist.utl.pt"" rel=""nofollow} ; J. Santana^a ; ^c ; ^{jsantana@ist.utl.pt"" rel=""nofollow}
• 关键词：HVDC multilevel converters ; Bipolar HVDC VSC ; dc Bus voltages balancing ; Predictive control strategy
• 刊名：Electric Power Systems Research
• 出版年：2011
• 出版时间：July 2011
• 年：2011
• 卷：81
• 期：7
• 页码：1436-1445
• 全文大小：1160 K

文摘

Voltage source multilevel power converter structures are being considered for high power high voltage applications where they have well known advantages. Recently, full back-to-back connected multilevel neutral diode clamped converters (NPC) have been used in high voltage direct current (HVDC) transmission systems. Bipolar back-to-back connection of NPCs have advantages in long distance HVDC transmission systems, but highly increased difficulties to balance the dc capacitor voltage dividers on both sending and receiving end NPCs.

This paper proposes a fast optimum-predictive controller to balance the dc capacitor voltages and to control the power flow in a long distance HVDC system using bipolar back-to-back connected NPCs. For both converter sides, the control strategy considers active and reactive power to establish ac grid currents on sending and receiving ends, while guaranteeing the balancing of both NPC dc bus capacitor voltages. Furthermore, the fast predictive controller minimizes the semiconductor switching frequency to reduce global switching losses.

The performance and robustness of the new fast predictive control strategy and the associated dc capacitors voltage balancing are evaluated.