DC Solid-state Circuit Breaker Research Articles

Mitigating Gate Oscillations of Parallel SiC MOSFETs for Enhanced Performance in DC Solid-State Circuit Breaker

Mitigating Gate Oscillations of Parallel SiC MOSFETs for Enhanced Performance in DC Solid-State Circuit Breaker

Soft Turn-Off DC Solid-State Circuit Breakers With Flexible Dual Tripping Schemes

Soft Turn-Off DC Solid-State Circuit Breakers With Flexible Dual Tripping Schemes

Research on Breaking Function for Two Bidirectional Γ-source DC Solid-state Circuit Breakers

Research on Breaking Function for Two Bidirectional Γ-source DC Solid-state Circuit Breakers

Snubber Branch Design and Development of Solid-State DC Circuit Breaker

This research proposes a solid-state DC circuit breaker for low voltage DC system based on reverse-blocking IGCT. The circuit breaker topology gets easier as a result of reverse-blocking IGCTs' ability to withstand reverse voltage. To further enhance the breaking process, we develop a snubber branch with metal oxide varistors (MOV) and capacitance. The advantages and disadvantages of three distinct snubber branches-the no-snubber, the resistance-capacitance (RC), and the MOV-C snubber branch-are then contrasted. In addition to suppressing high-frequency oscillation caught by the parasitic MOV parameters, the structure with MOV-C snubber branch also blocks low frequency harmonics brought on by RC snubber branch. Moreover, this structure can slow down the rate at which the voltage rises during the breaking process. Comparatively speaking to the RC snubber branch and no-snubber branch structures, it is more appropriate for solid-state DC circuit breakers. Finally, a solid-state DC circuit breaker prototype based on RB-IGCT and MOV-C branch has been created. The maximum overvoltage is 1.5kV, and the rated voltage is 750V. The maximum breaking current is 10kA, and the rated current can be 2kA.

Compact Wireless Energy Pick-Up System Coupled Gate-Drive for Medium-Voltage Power Devices in Modular DC Solid-State Circuit Breakers

Compact Wireless Energy Pick-Up System Coupled Gate-Drive for Medium-Voltage Power Devices in Modular DC Solid-State Circuit Breakers

Analysis of Discharge Failure Mechanism of IGBT Power Modules

IGBT power modules are usually used as circuit-breaking components in power systems, and are widely used in solid-state DC circuit breakers, hybrid DC circuit breakers, all-electric aircraft, high-speed railways, new energy vehicles, and power transmission systems. In these systems, IGBT power modules are usually faced with extremely harsh working conditions and there is a failure risk. Insulation degradation should be a cause for concern as a potential path of power module failure. In this paper, the discharge phenomena of the IGBT power module were observed based on Intensified Charge Coupled Devices (ICCD), and the triple junctions composed of copper–ceramic–silicone gel inside IGBT were found as the discharge points. Furthermore, the directed bonded copper (DBC) ceramic filled with silicone gel was used as a test sample to study the discharge failure process, including the partial discharge (PD), surface charges, and electric trees. The mechanism of discharge failure is discussed and analyzed. The insulation degradation process is accompanied by phenomena such as severe partial discharge and rapid electric tree growth. This research provides support for the analysis idea and guidance of the research method for the cause of power module failure.

Applicability Analysis of a Multi-Filar Meander R-SFCL and an RSC-DCCB in an MMC-MTDC Grid

modular multilevel converters (MMC)-based high voltage direct current (HVDC) topology is an effective solution to solve the power transmission demand between countries. However, the initial fault current can rise to several tens of kA within a few ms by capacitor discharge during a fault. This fault current can permanently damage the converter components and cables. Therefore, to increase the stability of the system, the protection of the DC system is very important. DC system protection methods include circuit breaker technologies and current limiting technologies. We have selected a circuit breaker with combined resonant current source (RCS) and a resistive superconducting fault current limiter (SFCL) as protection methods for the DC system. The RSC-DC circuit breaker has no conduction power losses by on-state voltage drop. Therefore, it can provide stable interruption compared to a solid-state DC circuit breaker. Since the resistive SFCL has a very fast response time, it can effectively limit the rapidly rising initial fault current. We wound the superconducting tape by the multi-filar meander method. This method can increase the length of the superconducting tape used and speed up the bubble diffusion during quenching. We modeled an MMC-HVDC grid, resistive SFCL, and RCS DC circuit breaker using PSCAD/EMTDC. In this paper, the interrupting and current limiting characteristics are discussed when the resistive SFCL and the RCS-DC circuit breaker proposed by us are connected to the MMC-based MTDC grid. In the simulation, the current limiting factor of resistive SFCL was up to about 58%. In addition, the combination of resistive SFCL and RCS-DC circuit breaker can shorten the interruption time when the fault occurs.

Fully Soft-Switched DC Solid-State Circuit Breakers

This letter presents a new fully soft-switched dc solid-state circuit breaker (SSCB). During dc current interruption, both main and auxiliary switches turn off under zero current switching (ZCS). A novel inductor-capacitor-capacitor (LCC)-based active injection circuit (AIC) is proposed. It eliminates transient power on switches with a fast operation, which enhances reliability. Experiments of a 350 V/90 A prototype validate ZCS operation for both switches. The response speed reaches 4 μs, and the maximum voltage on switches is 759V, which is within a safe range. This letter is accompanied by slides as multimedia material demonstrating major innovations and contributions.

SCR-Based Bidirectional Circuit Breaker for DC System Protection With Soft Reclosing Capability

The emergence of power electronics has lead to a paradigm shift towards dc grids, which are widely recognized to provide better performance and efficiency. However, fault isolation is one of the prime challenges of dc grids due to the absence of current zero-crossing. With this motivation, this paper introduces a novel silicon-controlled-rectifier-based bidirectional dc solid-state circuit breaker. In addition to its ability to isolate the faulty section, the proposed topology can also provide soft reclosing capability, which aids in reducing repetitive voltage and current stress on the breaker and current feeding components. Moreover, the heat loss by the surge suppression devices during reclosing is negligible. Equations are derived to analyse the effect of component values on various circuit-level considerations. Simulation and scaled-down experimental results are presented to verify the operation of the breaker under various operating conditions.

Fault Current Bypass-Based DC SSCB Using TIM-Pack Switch

This letter proposes a new bypass-based solid-state circuit breaker (SSCB) using thyristor-IGBT-MOV (TIM)-Pack switch for DC applications. The presented SSCB features three key advantages. First, the stored inductive energy of dc systems is prevented to flow through faulty sections, and the response speed is within microseconds, which enhances safety. Second, MOVs are disconnected from the power line during OFF-state, which improves reliability. Third, the proposed topology takes full use of the benefits of high-power rating thyristors in a TIM-Pack. To validate the proposed SSCB, experiments of a 600 V/145 A scale-down prototype are conducted. Results show that the fault current reduces to zero in 6 s; peak voltage on the main and auxiliary thyristors reaches 826 V and 600 V, respectively; while, overshoot voltage on the main and auxiliary IGBTs reaches 185 V and 245 V, respectively.

A Novel Oscillating-Commutation Solid-State DC Breaker Based on Compound IGCTs

Medium voltage dc system has fast rise rate in the event of a short-circuit fault. To avoid high-peak fault current, it is necessary to configure dc circuit breaker with fast operation. Solid-state dc circuit breaker has short breaking time and high reliability, which is suitable for Dc system. In this letter, a novel oscillating-commutation solid-state dc circuit breaker based on compound integrated gate-commutated thyristors (IGCTs) is proposed. By combining IGCTs with different advantages, such as high current breaking and high withstand-voltage capability, the proposed dc breaker has the advantages at less breaking time, high performance, low cost, and small volume. The working principle of the proposed scheme is described in detail, and an 8 kV prototype with 7 kA current breaking ability is built to verify its feasibility.

A Passive Thyristor-Based Hybrid DC Circuit Breaker

DC circuit breaker (DCCB) is one of the most important technologies for safe and reliable operation of dc grid. And the hybrid DCCB (HCB) is obviously promising in high-voltage application area, because it combines both the advantages of mechanical DCCB and solid-state DCCB. At present, insulated gate bipolar transistors (IGBTs) are generally used for configuring the main breaker branch in the HCB. Compared with IGBTs, thyristors have the merits of ability to bear higher surge current, higher reliability, and lower cost, thus being more economical and reliable when used to replace IGBTs. Right now, several topologies of thyristor-based HCBs have been proposed, but the economy, reliability, control complexity, as well as the operation performance, can still be improved. In this article, a novel passive thyristor-based HCB is proposed. Compared with existing IGBT-based HCBs, the proposed HCB has significant advantages on economy and reliability, due to the application of thyristors for replacing IGBTs. In addition, in the proposed scheme, the required thyristors count is reduced and the additional power supply for capacitor precharging is saved, so the investment and control complexity are both cut down. The feasibility and superiorities of the proposed HCB are validated with scaled-down experiment test and 500-kV-level simulation case study.

Protection of DC Microgrids Based on Complex Power During Faults in On/Off-Grid Scenarios

The DC microgrid is an effective platform for integration of renewable energy sources, energy storage systems, and smart electronic loads. However, the integration of distributed generators can result weak fault currents with change in its direction during fault conditions, which lead to failure of conventional over-current relays with poor coordination. The above scenario may exhibits relay mal-operation and force the DC microgrid into blackout mode which is extremely undesirable. Thus, this paper proposes an complex power concept (real and imaginary), which can be extracted using Fast Fourier Transform (FFT) to construct the effective protection schemes for rapid short-circuit fault detection and fault isolation in a DC microgrid. To achieve fault isolation, solid-state DC circuit breakers are used in conjunction with proposed real and imaginary power, which is extracted from the total FFT power signal (i.e. by using bus voltage and line current). Further, the relay trip threshold value for real and imaginary power is also determined under various pole-pole (P-P) and pole-ground (P-G) fault scenarios in the DC microgrid. The proposed protection scheme is validated on simple and modified IEEE 9-bus DC microgrids under various P-P and P-G fault scenarios during On/Off-Grid modes through MATLAB/Simulink software. The simulation results reveal that the proposed protection scheme based on real and imaginary power has accurately identified the fault in the simulated DC microgrids. Thus, the proposed complex power based fault identification approach can be quite effective for protection of DC microgrids during On/Off-Grid scenarios.

SiC JFETs Modular Cascaded Method with Active Clamp Control Strategy for DC Solid-State Circuit Breaker

SiC JFETs Modular Cascaded Method with Active Clamp Control Strategy for DC Solid-State Circuit Breaker

Fast protection strategy for monopole grounding fault of low-voltage DC microgrid

• This paper presents a low-voltage DC microgrid ground short-circuit fault protection system based on positive channel metal oxide semiconductor (PMOS). • In case of ground short-circuit fault in DC microgrid, the coupling energy of the short-circuit current makes the PMOS to be turned off reliably. • In addition, because the primary inductance of the transformer plays a certain current limiting role, the turn-off current of PMOS will not increase sharply. Low voltage DC microgrid has attracted more and more attention in smart grid with its advantages such as low network loss, large transmission capacity and easy direct access to distributed power supply. However, compared with the traditional AC microgrid, the DC microgrid lacks inertia support and the fault develops rapidly, which makes the existing short-circuit current protection technology difficult to meet the requirements of accurate and efficient troubleshooting. Therefore, this paper presents a low-voltage DC microgrid ground short-circuit fault protection system based on positive channel metal oxide semiconductor (PMOS) self-powering DC solid-state circuit breaker protection elements, and verifies the feasibility and effectiveness of the protection system through simulation experiments. The experimental results show that the proposed protection system based on solid state circuit breaker will not affect the voltage of DC microgrid when it is normally on; In case of ground short-circuit fault in DC microgrid, the coupling energy of the short-circuit current makes the PMOS to be turned off reliably. In addition, because the primary inductance of the transformer plays a certain current limiting role, the turn-off current of PMOS will not increase sharply. The solid-state circuit breaker can effectively block the fault without a buffer circuit, which has a good application prospect.

Fast Y-Type Thyristor-Based DC SSCB Using Complementary Commutation in a Capacitor–Capacitor Pair Structure

This article proposes a new thyristor-based dc solid-state circuit breaker (SSCB) named Y-type. Main contributions focus on a new complementary commutation circuit including a capacitor–capacitor pair, which features three remarkable advantages. First, a fast commutation is achieved using a countercurrent pulse injection by the capacitor–capacitor pair structure. Second, metal-oxide varistors (MOVs) are disconnected from the power line when SSCB is <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> , which solves the reliability issue due to the MOV degradation and enhances the voltage utilization rate of the main switch. Third, benefiting from the capacitor–capacitor pair structure, reliable reclosing and rebreaking are obtained for practical applications. Experiments are conducted on a 400 V/120 A prototype to validate the proposed Y-SSCB. The peak voltage on the main and auxiliary thyristors reaches 773 and 400 V, respectively. Also, the peak voltage on the auxiliary capacitors pair reaches 740 and 400 V. The Y-SSCB achieves a fast reaction time of 80 μs in interrupting 120 A short-circuit fault current.

Design and Analysis of a DC Solid-State Circuit Breaker for Residential Energy Router Application

Energy routers act as an interface between the distribution network and electrical facilities, which meet the requirements of clean energy substitution and achieve the energy sharing and information transmission in the energy network. However, the protection of the dc load side of residential energy routers including interruption and isolation of short-circuit fault currents is vital for discussion. Since the traditional mechanical and hybrid circuit breakers for dc fault protection have the drawback of slow operation, a solid-state circuit breaker (SSCB) is an optimal solution for fast dc fault interruption. In this paper, a dc SSCB is proposed that uses an RCD + MOV snubber circuit, which is considered the best and most complete circuit used in common SSCBs. There are two main contributions in this paper: First, a dc SSCB is designed, which isolates both positive and negative terminals of a circuit and its working principle and operating modes along with the formulas for calculation of crucial time intervals, voltages, and currents along with the design procedure are provided. Second, a soft turn-on auxiliary is designed to prevent a high current surge caused by the capacitance difference between the source and the load. The experimental results demonstrate the proper performance of the topology and the validity of the findings.

A Modular Bidirectional Solid-State DC Circuit Breaker for LV and MVDC Grid Applications

Direct current (dc) microgrids are increasingly gaining attention in industrial applications due to their simpler and more efficient integration with renewable energy resources and energy storage elements. The dc grid demands a faster, compact, cost-effective, and fault-tolerant protective system for reliable operation. To address the above challenges, this article proposes a bidirectional solid-state dc circuit breaker topology that guarantees reliable operation of dc grids [low voltage dc (LVDC) and medium voltage dc (MVDC)]. A modular extension of the proposed circuit breaker is also presented, resulting in better reliability, scalability, and fault-tolerant operation. The circuit breaker is derived using power semiconductor devices [silicon-controlled rectifiers (SCRs) and insulated-gate bipolar transistors (IGBTs)], with SCR acting as a main power interruption device. Salient features of the proposed topology include modularity, use of low-power rated devices, low-current rated sensors, and pre-fault interruption. A detailed mathematical analysis validating the design and operation of the proposed modular circuit breaker is presented. Moreover, the article also highlights the merits and limitations of the proposed concept. Finally, a laboratory prototype is developed with a system specification of 400 VDC/14 A to validate the performance of the proposed circuit breaker with single and modular operations, which is in line with the obtained simulation results. To verify current sharing between the modules, a few non-ideal conditions such as the use of non-identical main SCRs and turn-on delay are considered and tested on the developed 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.

Modular Bidirectional Solid-State DC Circuit Breaker for Next-Generation Electric Aircrafts

The design of electric power systems (EPSs) for the aviation industry has become a major research area to reduce the global annual CO2 emission caused by the transportation sector. DC power distribution is envisaged to meet the high load demand of more-electric and all-electric aircraft power architectures. Nonetheless, the development of dc distribution is significantly impeded by the challenges associated with dc system protection. Aircraft EPS demands high speed and high current protection. Among various dc circuit breaker (DCCB) technologies, solid-state dc circuit breakers (SSCBs) operate at higher speeds. To make them withstand high current ratings, modular structured DCCBs with the highest power density, reliability, and bidirectional fault interruption capability are presented in this article. The existing DCCBs fail to comply with the design constraints such as faster response, high current breaking, and compact design. This article proposes a coupled inductor-based modular bidirectional SSCB that employs the magnetic coupling principle for counter-current commutation of thyristors. The proposed modular SSCB exhibits a fast fault interruption time of approximately 200 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> . The analysis, design, and experimental validation of the proposed SSCB are presented in detail. Each module in the prototype is designed for a system rating of 270 V/15 A. The performance of this SSCB for single- and two-module operations is experimentally verified for a 270-V/20-A dc system.