Supercapacitors can store a million times more energy per unit mass or volume compared to electrolytic capacitors. Due to their low internal resistance, they are capable of driving or absorbing pulsative high currents. Over the last quarter, century supercapacitor (SC) manufacturers have developed several families of mass-scale devices with high-power density and a longer cycle life that helped the end-users to improve their energy storage systems and products. Today, there are three common device families, namely, (i) symmetrical double-layer capacitors (EDLCs), (ii) hybrid capacitors with a lithium electrode, and (iii) battery capacitors based on pseudo capacitance concepts. This review paper compares these families and provides an overview of several state-of-the-art applications in electric vehicles (EVs), microgrids, and consumer electronics.

While traditional AC mechanical circuit breakers can protect AC circuits, many other DC power distribution technologies, such as DC microgrids (MGs), yield superior disruption performance, e.g., faster and more reliable switching speeds. However, novel DC circuit breaker (DCCB) designs are challenging due to the need to quickly break high currents within milliseconds, caused by the high fault current rise in DC grids compared to AC grids. In DC grids, the circuit breaker must not provide any current crossing and must absorb surges, since the arc is not naturally extinguished by the system. Additionally, the DC breaker must mitigate the magnetic energy stored in the system inductance and withstand residual overvoltages after current interruption. These challenges require a fundamentally different topology for DCCBs, which are typically made using solid-state semiconductor technology, metal oxide varistors (MOVs), and ultra-fast switches. This study aims to provide a comprehensive review of the development, design, and performance of DCCBs and an analysis of internal topology, the energy absorption path, and subcircuits in solid-state (SS)-based DCCBs. The research explores various novel designs that introduce different structures for an energy dissipation solution. The classification of these designs is based on the fundamental principles of surge mitigation and a detailed analysis of the techniques employed in DCCBs. In addition, our framework offers an advantageous reference point for the future evolution of SS circuit breakers in numerous developing power delivery systems.

This article introduces a novel technique known as bidirectional thyristor capacitor designed to interrupt dc currents effectively and mitigate power surges in low-voltage (LV) solid-state dc circuit breakers (SS-DCCB). The method employs parallel snubber capacitors to absorb switching effects, subsequently releasing stored energy during the subsequent switch operation. The model incorporates considerations for both line and load inductances, offering a realistic portrayal of a dc system and ensuring authentic protective measures. To validate the efficacy of this approach, practical results from the system are cross-referenced with simulation outputs, validating the credibility of the research findings. Additionally, an ARM microcontroller is programmed to control the sequence of actions among the active SS switches, optimizing their performance. The proposed LV SS-DCCB operates at a voltage level of 48 VDC and nominal current of 8 A. However, the design is scalable and can be extended to accommodate higher voltage and current ranges.

This research introduces the Bidirectional Passive Technique (BPT), a novel topology for low-voltage solid-state circuit breakers (SSCBs) that is based on the RCD model. BPT achieves fast switching, minimizes surge voltage across the main switch, and reduces circuit complexity by limiting active components to the primary switch. The study details the working principles, operating modes, and design procedure, supported by key equations for time intervals, voltages, and currents. Validation through MATLAB simulations and practical tests demonstrates rapid interruption within 40 μsec, ensuring effective protection for loads and DC microgrid (DC-MG) systems. The proposed model targets low-voltage systems (48 V) with a 10 A threshold current for the Future Architecture of Network Project, demonstrating the high effectiveness of the BPT in DC microgrid protection..