Low Voltage Skin Burns

PEDIATRICS ◽  
1971 ◽  
Vol 48 (5) ◽  
pp. 831-832
Author(s):  
Charles W. Jarvis ◽  
Donald A. Voita
Keyword(s):  
Cardiac Function ◽  
High Voltage ◽  
Direct Current ◽  
Low Voltage ◽  
Electronic Devices ◽  
Laboratory Safety ◽  
High Voltage Direct Current ◽  
Electrical Devices ◽  
Different Types ◽  
The Subject

The hazards accompanying the increasing use of line-operated electrical devices for diagnosis and therapy as well as the more common hospital appliances such as electrically operated beds, television sets, radio sets, and so forth have been recently reemphasized.1 Most physicians are aware of the dangers of alternating current (60 Hz AC) or of high voltage direct current (DC) , especially in relation to cardiac function. However, few physicians seem to be aware of the hazards of low voltage direct current. A standard text2 on laboratory safety fails to mention the subject. Low voltage direct current is used with many different types of miniature electronic devices and iontophoresis.

scholarly journals High Conversion Ratio Converter Using Half-Bridge Sub-Modules

2020 ◽  
Vol 4 (5) ◽  
pp. 110-115
Author(s):  
Shalini Roy ◽  
Rahul Pandey
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Modular Design ◽  
Low Voltage ◽  
Conversion Ratio ◽  
Transmission Systems ◽  
Multilevel Converters ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
High Conversion Ratio

An appreciable and significant assess of consideration and mindset is currently growing up for power dc-dc converters and its further more consideration is taken towards adoption of Modular-Multilevel Converters (MMC). The paper presents a transformer less MMC by the means of superior and advanced conversion ratio for higher dc-dc power conversion. This converter is being capable of utilized mutually for both the Medium Voltage Direct Current (MVDC) transmission systems and High Voltage Direct Current (HVDC) transmission systems, due to its some remarkable distinctive attributes such as modular design, scalability, consistency, tolerance of failures, larger step up and step down ratio and lowers filtering requirements. The MMC idea connects N low voltage sub-modules in sequence to produce a high voltage output. Thus there is no complex control algorithm necessary to stabilize or balance the voltages in every sub-module. Thus the simulation and analysis of a MMC design connected with stray inductances in order to reduce losses is done with an instance of 11-times stepping up ratio.

scholarly journals Modular Multi-Port Ultra-High Power Level Power Converter Integrated with Energy Storage for High Voltage Direct Current (HVDC) Transmission

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2711 ◽  
Author(s):  
Sen Song ◽  
Wei Li ◽  
Kai Ni ◽  
Hui Xu ◽  
Yihua Hu ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Voltage ◽  
Direct Current ◽  
Power Plants ◽  
High Efficiency ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Power Converter ◽  
Hvdc Transmission ◽  
High Voltage Direct Current

To connect renewable energy sources (RESs) with a unity-grid, energy storage (ES) systems are essential to eliminate the weather fluctuation effect, and high voltage direct current (HVDC) transmission is preferred for large-scale RESs power plants due to the merits of low cost and high efficiency. This paper proposes a multi-port bidirectional DC/DC converter consisting of multiple modules that can integrate ES system and HVDC transmission. Thanks to the adoption of three-port converters as submodules (SMs), ES devices, for example, batteries, can be decentralized into SMs and controlled directly by the SMs. Additionally, SMs are connected in a scalable matrix topology, presenting the advantages of flexible power flows, high voltage step-up ratios and low voltage/current ratings of components to satisfy the requirements of HVDC transmission. Furthermore, the control flexibility and fault tolerance capability are increased due to the matrix topology. In this paper, the analysis of the novel modular multi-port converter is introduced, and its functions are verified by the simulation results in PSIM.

scholarly journals Modeling and Enhanced Control of Hybrid Full Bridge–Half Bridge MMCs for HVDC Grid Studies

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 180 ◽  
Author(s):  
Ricardo Vidal-Albalate ◽  
Jaume Forner
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
High Voltage ◽  
Direct Current ◽  
Simplified Models ◽  
Multilevel Converters ◽  
Electromagnetic Transient ◽  
High Voltage Direct Current ◽  
Modular Multilevel Converters ◽  
Different Types

Modular multilevel converters (MMCs) are expected to play an important role in future high voltage direct current (HVDC) grids. Moreover, advanced MMC topologies may include various submodule (SM) types. In this sense, the modeling of MMCs is paramount for HVDC grid studies. Detailed models of MMCs are cumbersome for electromagnetic transient (EMT) programs due to the high number of components and large simulation times. For this reason, simplified models that reduce the computation times while reproducing the dynamics of the MMCs are needed. However, up to now, the models already developed do not consider hybrid MMCs, which consist of different types of SMs. In this paper, a procedure to simulate MMCs having different SM topologies is proposed. First, the structure of hybrid MMCs and the modeling method is presented. Next, an enhanced procedure to compute the number of SMs to be inserted that takes into account the different behavior of full-bridge SMs (FB-SMs) and half-bridge submodules (HB-SMs) is proposed in order to improve the steady-state and dynamic response of hybrid MMCs. Finally, the MMC model and its control are validated by means of detailed PSCAD simulations for both steady-state and transients conditions (AC and DC faults).

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