The majority of power losses in solar inverter systems are driven by the root mean square (RMS) DC current in the input loop and the voltage stress imposed on inverter components. The Supercapacitor-Assisted Inverter (SCA-inverter) technique based on the Supercapacitor-Assisted Loss Management (SCALoM) concept, reduces these losses by partitioning the load of a single central inverter into an even number of smaller inverters, integrated with a set of supercapacitor (SC) modules. This approach effectively doubles the inverter system’s input voltage range without having to increase the voltage rating of the components, while halving the input RMS current by a factor of two. This paper presents an experimental efficiency validation of a proof of concept prototype (PoC) of a four-SCA-inverter system and a single inverter delivering the same cumulative power output upto 200W. The proposed technique allows the use SC modules to provide uninterruptible DC power supply (UPS) functionality without having to rely on conventional battery packs.

Supercapacitor assisted loss management (SCALoM) concept has laid the theoretical foundation to develop high efficiency power converters for renewable energy systems using supercapacitors as lossless voltage droppers and energy buffers. SCALoM theory is applicable to inverter combinations in reducing overall losses, mainly occurring in the input loop, including losses in the DC bus capacitor.Supercapacitor assisted (SCA) multi-inverter technique reduces the voltage stress on the internal components of inverters enabling the use of more efficient lower voltage rated components. A summary of the theoretical foundations with reference to previous works on the topic is presented first. The four-SCA-inverter technique discussed in this paper extends the input voltage range of an inverter system by two times and reduces the input loop current by two times. The preliminary results obtained from the first experimental prototype of the 700W four-SCA-inverter system coupled with four identical 250F supercapacitor modules switched at low frequencies (less than 0.02 Hz), show up to 2.53% of efficiency gain at the inverter end. Additionally, proposed technique provides unquantified efficiency gains by reducing the ripple currents in the system, functioning as an energy buffer. Development of a high power capable SCA-inverter prototype is in progress.

DC circuit breakers have become an essential protection element for DC buses in renewable energy and DC microgrid systems. Given that there are no zero crossings in a DC power supply compared to an AC waveform, arc extinguishing is a difficult process in DC circuit breakers. Solid state switches are proposed in solving this problem, but their cost is generally unaffordable in general applications, except for marine, military and aviation etc. Hence, commercial and mass-produced DC breakers are modified versions of AC breakers. This paper details different passive component options for absorbing the energy in the electric arc/plasma, including the use of supercapacitors.

Energy experts and planners are focusing on the decarbonization of power systems as a potential solution to challenges currently faced by the grid operators, customers, and regulatory authorities. DC Microgrids are a secure, clean, green, and low carbon-option for applications in many rural and urban locations. Due their resilient, self-reliant, and robust nature, they are preferred against the AC grids. DC grids require fewer power converting stages relative to the AC grids, thereby reducing the AC-DC conversion losses. DC microgrids, unlike the AC microgrids, do not have to synchronize their generators and can provide connection of various types of distributed energy resources such as the PV panels and DC loads through their common DC bus. However, the DC Microgrids are susceptible to the EMI radiation due to the high switching operations of the DC-DC buck converters. This research provides an overview of the MATLAB/Simulink model of the DC microgrid system and presents key results from its simulation study undertaken to estimate the conducted Electromagnetic Interference arising from the interactions between the Buck converters. A standalone Low Voltage (LV) DC Microgrid model was built and simulated with and without the presence of EMI filters. Spectrum analysis was performed on the DC-DC buck converter under both conditions which confirmed that the EMI filters are useful in reducing the EMI effects.

The supercapacitor-assisted low-dropout (SCALDO) regulator is an extra-low frequency technique for designing high efficiency, low noise, step-down DC-DC converters with a supercapacitor (SC) energy circulation front-end in series with an LDO regulator. Due to the nature of the SC switching network at the front-end, one can tend to consider the SCALDO technique as a variation of a charge pump topology. The scope of this paper is to compare the major topological differences of the SCALDO regulator and the step-down charge pumps and hybrid-charge pump converters. The operation principles of conventional step-down switched-capacitor DC-DC converters are described, their limitations are identified, and the advantages of hybrid charge pump converters are also highlighted. Then, the SCALDO concept is discussed in detail. The topological differences of the SCALDO and charge pumps are identified, and the performance characteristics are compared concerning the output current driving capability, operating frequency, switching ripple, efficiency, power density, and complexity.

Supercapacitor-assisted low-dropout (SCALDO) regulator technique is gradually developing as a novel design approach for high-efficiency, low-frequency DC-DC converters. This technique increases the end-to-end efficiency while maintaining the useful benefits of a linear regulator such as the low output noise, fast dynamic response, and less electromagnetic interference (EMI) and radio-frequency interference (RFI) issues. It is essential in SCALDO regulators to have primary circuit protection measures to safeguard the converter and the output load during external conditions such as overcurrent, overvoltage and undervoltage. This paper provides an insight into applicable circuit protection techniques so that SCALDO regulator designers can integrate them to make a robust design. The proposed protection techniques are tested on a 12–5 V discrete component-based SCALDO regulator developed in MATLAB SIMULINK simulation.