A Novel Topology of Hybrid HVDC Circuit Breaker for VSC-HVDC Application

Abstract

Abstract:The use of high voltage direct current (HVDC) circuit breakers (CBs) with the capabilities of bidirectional fault interruption, reclosing, and rebreaking can improve the reliable and safe operation of HVDC grids. Although several topologies of CBs have been proposed to perform these capabilities, the limitation of these topologies is either high on-state losses or long time interruption in the case bidirectional fault current interruption. Long time interruption results in the large magnitude of the fault current in the voltage source converter based HVDC (VSC-HVDC) system due to the high rate of rise of fault current. This paper proposes a new topology of hybrid CB (HCB) with lower conduction loss and lower interruption time to solve the problems. The proposed topology is based on the inverse current injection method, which uses the capacitor to enforce the fault current to zero. In the case of the bidirectional fault current interruption, the capacitor does not change its polarity after identifying the direction of fault current, which can reduce the interruption time accordingly. A switching control algorithm for the proposed topology is presented in detail. Different operation modes of proposed HCB, such as normal current mode, breaking fault current mode, discharging, and reversing capacitor voltage modes after clearing the fault, are considered in the proposed algorithm. The proposed topology with the switching control algorithm is tested in a simulation-based system. Different simulation scenarios such as temporary and permanent faults are carried out to verify the performance of the proposed topology. The simulation is performed in the Matlab/Simulink environment.

New Differential Protection Method for Multiterminal HVDC Cable Networks

“…Use of HVDC circuit-breakers: circuit-breakers based on power electronics can switch-off fault currents in less than 2 ms but have considerable losses in normal operation [23]. Hybrid HVDC circuit-breakers can cut fault currents up to 5 ms with reasonable losses [24][25][26][27]. Another option is the use of mechanical circuit-breakers considering breaking times about 10 ms, voltages up to 250 kV and fault currents with values in the range of 8 kA [28].…”

New Differential Protection Method for Multiterminal HVDC Cable Networks

“…-Use of HVDC circuit breakers: Circuit breakers based on power electronics can switch off fault currents in less than 2 ms but have considerable losses in normal operation [23]. Hybrid HVDC circuit breakers can cut fault currents up to 5 ms with reasonable losses [24][25][26][27]. Another option is the use of mechanical circuit breakers considering breaking times about 10 ms, voltages up to 250 kV, and fault currents with values in the range of 8 kA [28].…”

A Harmonic Based Pilot Protection Scheme for VSC-MTDC Grids with PWM Converters

“…However, technical challenges exist in the protection and control of VSC-MTDC networks [4]. Fast fault isolation is only possible using DC breaker (DCCB)s [5] or converters with fault blocking capability [6]. Additionally, selective and fast detection of faults is difficult for the protection algorithm, because it must be done in less than 5 milliseconds in order to have minimum damage in HVDC converter switches [7] and correctly detect the faulty section of the transmission grid.…”