Coordinated Control Strategy of DC Fault Ride-through for the WF Connected to the Grid Through the MMC-HVDC

Abstract

Aiming at the problems of DC fault isolation and power surplus in the HVDC system with large-scale wind farm (WF) integration after single-pole grounding fault, this article designs a modified current transfer modular multilevel converter (M-CT-MMC) topology with DC fault isolation and power dissipation functions. The DC fault current can be isolated through the coordination of each branch of the M-CT-MMC. In terms of surplus power consumption, the control mode switching strategy of the M-CT-MMC is designed to improve the power transmission capability of the non-fault pole and enable it to absorb surplus power independently. Furthermore, a coordinated control strategy of wind turbines and dissipation resistors is designed to absorb surplus power. With the advantages of fast response speed of wind turbines and reliable dissipation resistance, DC fault ride-through under different working conditions is realized. Finally, the effectiveness and feasibility of the coordinated control strategy for DC fault ride-through are verified.

Advanced Protection for the Smart Grid

“…The DC circuit breakers (DCCBs) is considered as an essential technology to isolate the fault area and maintain normal operations of non-fault areas in HVDC grids. There are three main groups of DCCB: mechanical DCCBs (Shi et al, 2015;Lin et al, 2016), solid-state DCCBs (Corzine and Ashton, 2012;Sano and Takasaki, 2014;Chang et al, 2016;Keshavarzi et al, 2017;Shu et al, 2020;Zhang et al, 2020;Xu et al, 2021), and hybrid DCCBs Sander et al, 2018). The hybrid DCCBs combine the merits of mechanical DCCBs and solid-state DCCBs and therefore is considered as an acceptable solution in HVDC grids.…”

“…The high voltage direct current grid based on the modular multilevel converter (MMC-HVDC), with the advantages of large transmission capacity, low loss, and high reliability, has broad development prospects in the fields of distributed power access, new energy delivery through isolated islands, and the interconnection of asynchronous AC grids Khosravi et al, 2021;Zhu et al, 2021;. In MMC-HVDC grids, the most ideal fault isolation method is to use a direct current circuit breaker (DCCB) to cut the fault line, which isolates only the fault area and ensures that the rest of the system can continue to operate normally (Franck, 2011;Xu et al, 2018;Oubelaid et al, 2022b).…”

Study on the characteristic of the grounding fault on the cascaded midpoint side of the hybrid cascaded HVDC system

“…With the commissioning of multiple new LCC-HVDCs, the power grid strength in the Yangtze Delta area of China will be reduced further, thus leading to an increased risk of commutation failure in LCC-HVDC and a gradual reduction in grid voltage stability, which in turn limits the scale of LCC-HVDC development (Shao and Tang, 2017). Following the rapid development of modular multilevel converter-based HVDC (MMC-HVDC) in recent years, the requirements for the recipient grid strength are low, and they have a certain fault ride-through capability; however, its rated voltage and transmission power are not as good as LCC-HVDC, and MMC-HVDC construction costs are higher compared with LCC-HVDC, thus limiting its application scale (Zhu et al, 2021;Saeedifard and Iravani, 2010;Swedesford et al, 2010). Therefore, hybrid HVDC technology, which considers the scale of the AC network as well as the system characteristics and combines the respective benefits of LCC-HVDC and MMC-HVDC, has become a novel technology used to solve the aforementioned problems and a major research focus in the field of HVDC.…”

Research on circuit breaker failure protection and the secondary accelerated fault isolation scheme of VSC-HVDC grids

“…The high voltage direct current grid based on the modular multilevel converter (MMC-HVDC), with the advantages of large transmission capacity, low loss, and high reliability, has broad development prospects in the fields of distributed power access, new energy delivery through isolated islands, and the interconnection of asynchronous AC grids (Wang et al, 2021;Khosravi et al, 2021;Zhu et al, 2021;Oubelaid et al, 2022a). In MMC-HVDC grids, the most ideal fault isolation method is to use a direct current circuit breaker (DCCB) to cut the fault line, which isolates only the fault area and ensures that the rest of the system can continue to operate normally (Franck, 2011;Xu et al, 2018;Oubelaid et al, 2022b).…”