Bidirectional DC Circuit Breaker Research Articles

DC circuit breaker: A topology with regenerative current breaking capability for DC microgrid applications

The modern DC grid is predominantly inductive due to several factors, including line inductance, and the use of current-limiting inductors to control fault current rising rates. These network inductances store a significant amount of energy during regular operation, which is either dissipated or freewheeled to ensure safe current breaking. This research article proposed a highly efficient bidirectional DC circuit breaker topology that not only provides safe current breaking but also effectively recovers the post-current breaking energy from the network’s inductance instead of dissipation. An extensive simulation investigation is performed in PSIM software to test the breaker capability for a 400V/400A DC system and the laboratory-scale 48V/1A experimental setup has been developed and employed for further validation purposes.

A Bidirectional DC Circuit Breaker Based on the Coupled Inductor for HVDC Applications

A Bidirectional DC Circuit Breaker Based on the Coupled Inductor for HVDC Applications

An Efficient Bidirectional DC Circuit Breaker Capable of Regenerative Current Breaking for DC Microgrid Application

The direct current circuit breaker (DCCB) is extensively employed in DC microgrid applications to protect the network during faults. However, numerous DC converters are combined in parallel to form a DC microgrid, which creates a large network inductance. The grid stores energy during regular operation, which repels instantaneous current breaking, and this stored energy needs to be eliminated after current breaking. Conventional topologies use different energy absorption methods to dissipate the stored energy after breaking the current. In this paper, an efficient bidirectional DC circuit breaker (EBDCCB) topology is introduced to extract and reuse this energy instead of dissipating it. The proposed topology has bidirectional power flow capability to meet the requirements of DC microgrid applications as energy storage devices are frequently utilized. Furthermore, EBDCCB shows drastically improved performance in terms of current breaking time, voltage stress, regenerated average current, and energy recovery efficiency compared to the conventional DCCB topology. The mathematical modeling and sizing of the components used in the proposed EBDCCB are elaborately analyzed, and detailed performance testing is presented along with extensive PSIM software simulation. Additionally, an experimental investigation is conducted on a laboratory-scale 48 V/1 A prototype.

Controlled Bidirectional DC Circuit Breaker With Zero Negative Current for High Load Shift Applications

Global electricity generation by renewable energy sources and the electrification of the transportation system are gaining more importance to mitigate climate change. The dc system plays a significant role in these developments. To protect dc systems, dc circuit breakers with advanced technology are required that are fast and reliable. Various solid-state dc circuit breakers, such as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$Z$</tex-math></inline-formula> -source and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$T$</tex-math></inline-formula> -source circuit breakers, have been presented in the literature to meet the dc system demand; however, these topologies suffer from limitations such as high conduction loss, complexity in design, no physical isolation, and presence of negative current flow in load during reclosing. To overcome the aforementioned limitations, a bidirectional solid-state dc circuit breaker (BD-SSCB) that detects the overload or short-circuit faults and responds instantaneously to mitigate the fault current has been proposed in this article. The controllable shutoff function is much needed in applications where sudden load change occurs continuously during the normal operation, such as varying acceleration of an electric vehicle. The proposed BD-SSCB is validated using spice simulations and hardware experiments with varying system parameters for a system rating of 400 V/10 A.

A Zero Crossing Hybrid Bidirectional DC Circuit Breaker for HVDC Transmission Systems

With the increasing demand for renewable energy power generation systems, high-power DC transmission technology is drawing considerable attention. As a result, stability issues associated with high power DC transmission have been highlighted. One of these problems is the fault current that appears when a fault occurs in the transmission line. If the fault current flows in the transmission line, it has a serious adverse effect on the rectifier stage, inverter stage and transmission line load. This makes the transmission technology less reliable and can lead to secondary problems such as fire. Therefore, fault current must be managed safely. DC circuit breaker technology has been proposed to solve this problem. However, conventional technologies generally do not take into account the effects of fault current on the transmission line, and their efficiency is relatively low. The purpose of this study is to introduce an improved DC circuit breaker that uses a blocking inductor to minimize the effect of fault current on the transmission line. It also uses a ground inductor to efficiently manage the LC resonant current and dissipate residual current. DC circuit breakers minimize adverse effects on external elements and transmission lines because the use of elements placed on each is distinct. All of these processes are precisely verified by conducting simulation under 200 MVA (±100 kV) conditions based on the VSC-based HVDC transmission link. In addition, the mechanism was explained by analyzing the simulation results to increase the reliability of the circuit in this paper.

A New Bidirectional DC Circuit Breaker With Fault Decision-Making Capability for DC Microgrid

DC circuit breaker (DCCB) plays an important role in dc system protection as an execution unit for disconnecting fault lines. However, due to the nature of dc current, it is a challenge for DCCB to quickly turn off and isolate the fault current. Therefore, a new bidirectional DCCB with decision-making capability based on Z-source topology is proposed in this article, which is able to respond to a fault in a few microseconds. The proposed topology uses only one coupled inductor with a central tap structure in the core part, which improves the utilization ratio of the coupled inductor and reduces the volume and cost of the DCCB. Compared with previous DCCBs, the proposed topology has a simpler structure, fewer windings and components, and smaller volume. In this article, the turn off process of the proposed topology under the line fault condition is analyzed in detail, and the hardware circuit design process is given. The performance of the proposed topology was verified by MATLAB simulation and hardware experiments.

Conceptual Design of Bidirectional Hybrid DC Circuit Breaker for Quench Protection of the CFETR

This technical note presents the conceptual design of bidirectional hybrid dc circuit breaker for quench protection circuit (QPC) of the China fusion engineering test reactor. The rated parameter of bidirectional hybrid dc circuit breaker is up to 70 kA and 15 kV. The novel scheme based on a mechanical breaker and the controlled static circuit breaker (SCB) in parallel is proposed. The mechanical breaker consists of three independent control contacts to realize the rapid transfer of the large current and fast recovery of dielectric strength. The SCB is composed of the insulated-gate bipolar transistors (IGBTs) unit and four diode units in a rectifier scheme for both current directions. Moreover, the feasibility of bidirectional dc circuit breaker, such as the turn-on reliability of IGBTs unit, and voltage sharing and current sharing of each IGBTs are investigated in this technical note, finally, the conceptual design result of the QPC is given.

A Z-Source-Based Bidirectional DC Circuit Breaker With Fault Current Limitation and Interruption Capabilities

DC microgrids have some attractive characteristics, which have being investigated to utilize in future electrical power systems. However, they have several essential challenges, such as limiting and interrupting fault current, which should be rectified to have high-performance dc microgrids. In this paper, an efficient dc bidirectional fault current limiter and interrupter (FCLI) based on Z-source topology is proposed to overcome some of the challenges in dc microgrids. The FCLI is a multifunction device, by which power flow direction control, circuit breaking, fault current limiting, and interrupting in a dc system can be handled. Analytical analysis of the FCLI is discussed in detail for different operation modes. Performance of the proposed FCLI in the different operation modes is evaluated using some simulations and experiments. The results confirm high capability of the device to realize appropriate operation in dc systems. Fast response time of fault current limitation and interruption, simple and reliable structure, and negligible conduction loss are the main features of the proposed FCLI.