Continuous commutation failure suppression strategy in hybrid multi-infeed HVDC transmission system

Abstract

For the wide application of high voltage direct current (HVDC) transmission engineering,the continuous commutation failure of line commutated converter HVDC (LCC-HVDC) has a seriously negative impact on the stable operation of the power system. Therefore,in order to mitigate the continuous commutation failure of LCC-HVDC in hybrid multi-feed HVDC system,from the perspective of increasing the LCC-HVDC commutation voltage,a coordinated control strategy for hybrid multi-infeed HVDC systems is proposed in this paper. According to the real-time reactive power shortage of the conventional DC,the reactive power and active power of voltage source converter HVDC (VSC-HVDC) output are dynamically adjusted by this strategy,thereby changing the transient stable operating point of VSC-HVDC. Through the coordinated control of this strategy,the continuous commutation failure of LCC-HVDC is suppressed and the transmission capacity of the active power of the DC transmission system is greatly improved. Finally,a simulation model of the hybrid dual-infeed HVDC system is built in PSCAD/EMTDC,and the effectiveness of the coordinated control strategy is verified.

Keywords

• hybrid multi-feed high voltage direct current system
• continuous commutation failure
• coordinated control
• additional reactive power control
• adaptive current limit
• dynamic power limiting