A Multi-Port Current-Limiting Hybrid DC Circuit Breaker

Abstract

Recently the hybrid multi-port DC circuit breaker (MP-DCCB) is becoming popular in protecting HVDC grids, thanks to their reduction of power electronics devices. In this paper, an enhanced multi-port current-limiting DCCB (MP-CLCB) for multiple line protection is proposed. The integrated fault current limiter (FCL) inside the MP-CLCB can clear the fault faster with slightly increased costs. To reduce the energy dissipation requirement for the surge arresters caused by the newly added current-limiting path, an energy transfer path which provides a loop with the inductors during the current decay stage is designed. The theoretical analysis of the precharging, current-limiting, fault interruption and energy dissipation of the MP-CLCB is carried out. Moreover, the design principles of the energy dissipation and the key parameters of the MP-CLCB are provided. The proposed approaches are verified through simulations in PSCAD/EMTDC. The results show that the MP-CLCB can replace multiple DCCBs, accelerate the fault current interruption and reduce the energy dissipation requirement for the surge arresters.

A Multi‐Port Current‐Limiting Hybrid DC Circuit Breaker Based on Thyristors

“…In addition, all inductances in the DC lines are equivalent to one inductor L ei , the inductances from the bus to the right side of the fault point in Line 2 is equivalent to L e2* . Since the equivalent resistor of MMC, the on-resistance of the switching component, and the resistance of DC line are relatively small, they have little effect on the calculation [20]. In order to obtain an analytical solution, these resistances are…”

“…Since MOV is a non-linear component, it is difficult to describe the volt-ampere characteristics. The common solution is to equate MOV to a DC voltage source during operation [20], in this paper, the equivalent DC voltage is denoted by U M . Substituting t 7 into (9) to obtain i f (t 7 ) = I 6 , then, i f is expressed as…”

“…The topology in Ref. [20] has the current-limiting capability, however, in order to bypass the current-limiting inductor during fault isolation, an additional energy transfer branch has to be set. Similarly, the main breaker in this topology still requires a large number of IGBTs.…”

“…In addition, most of the components in this topology are only put into operation at one certain stage, which causes device redundancy to a certain extent. Finally, all MP-HCB topologies in Refs [15][16][17][18][19][20] do not have adaptive reclosing capability. If the MP-HCBs reclose in a permanent fault, it will cause damage to the DC grid again.…”

A current‐limiting DC circuit breaker with power flow control capability

“…However, it is used in low-voltage dc distribution network. In [26], a multi-port current-limiting DCCB is proposed. Different DC lines share one main breaker to reduce cost.…”