Ultra-fast Utility Disconnect Switch for High Efficiency Medium Voltage UPS

Author(s):  
Pietro Cairoli ◽  
Rostan Rodrigues ◽  
Debrup Das ◽  
Simon Walton ◽  
Nick Elliott
Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4186
Author(s):  
Saddam Shueai Alnamer ◽  
Saad Mekhilef ◽  
Hazlie Mokhlis ◽  
Nadia M. L. Tan

This research proposes a four-level T-type inverter that is suitable for low-power applications. The presented topology outranks other types of inverters in terms of a smaller number of semiconductor devices, absence of passive components such as clamping diodes and flying capacitors, low switching and conduction losses, and high efficiency. The proposed topology is free from voltage deviation and unbalanced voltage occurrences that are present in other multilevel converters having clamping diodes or flying capacitors. The proposed inverter can extend to N levels using unequal dc-link voltage sources for medium-voltage application. The inverter employs the simple fundamental frequency staircase modulation technique. Moreover, this paper presents a current commutation strategy to prevent the occurrences of short circuit and minimizing the number of required switching devices and switching transitions, resulting in improving the efficiency of the inverter. This paper also analyses the theoretical converter losses showing lower switching and conduction losses when compared to existing four-level inverters. The experimental validation of the proposed inverter shows its operating feasibility and a low output voltage THD.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4763
Author(s):  
Grzegorz Debita ◽  
Przemysław Falkowski-Gilski ◽  
Marcin Habrych ◽  
Grzegorz Wiśniewski ◽  
Bogdan Miedziński ◽  
...  

Application of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can significantly reduce deployment costs. Additionally, it can be applied under difficult conditions, thanks to battery-powered devices. During an emergency situation (e.g., after coal dust explosion), the medium voltage cables are resistant to mechanical damage, providing a potentially life-saving communication link between the supervisor, rescue team, paramedics, and the trapped personnel. The assessment of such a system requires a comprehensive and accurate examination, including a number of factors. Therefore, various models were tested, considering: different transmission paths and types of coupling (inductive and capacitive), as well as various lengths of transmitted data packets. Next, a subjective quality evaluation study was carried out, considering speech signals from a number of languages (English, German, and Polish). Based on the obtained results, including both simulations and measurements, appropriate practical conclusions were formulated. Results confirmed the applicability of BPL-PLC technology as an efficient voice communication system for the oil and mining industry.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 977
Author(s):  
P. Madasamy ◽  
Rajesh Verma ◽  
A. Rameshbabu ◽  
A. Murugesan ◽  
R. Umamageswari ◽  
...  

Transformer-less (TL) inverter topologies have elicited further special treatment in photo-voltaic (PV) power system as they provide high efficiency and low cost. Neutral point clamped (NPC) multilevel-inverter (MLI) topologies-based transformer-less are being immensely used in grid-connected medium-voltage high-power claims. Unfortunately, these topologies such as NPC-MLI, full-bridge inverter with DC bypass (FB-DCBP) suffer from the shoot-through problem on the bridge legs, which affect the reliability of the implementation. Based on the previous above credits, a T type neutral point clamped (TNP)—MLI (TNP-MLI) with transformer-less topology called TL-TNP-MLI is presented to be an alternate which can be suitable in the grid-connected PV power generation systems. The suggested TL-TNP-MLI topologies free from inverter bridge legs shoot-through burden, switching frequency common-mode current (CMC), and leakage current. The control system of the grid interface with hysteresis current control (HCC) strategy is proposed. The effectiveness of the proposed PV connected transformer-less TNP-MLI topology with different grid and PV scenario has been verified through the MATLAB/Simulink simulation model and field-programmable gate area (FPGA)-based experimental results for a 1.5 kW system.


Sign in / Sign up

Export Citation Format

Share Document