Electric power

About: Electric power is a research topic. Over the lifetime, 73036 publications have been published within this topic receiving 636991 citations.

The Progressive Smart Grid System from Both Power and Communications Aspects

Abstract: The present electric power system structure has lasted for decades; it is still partially proprietary, energy-inefficient, physically and virtually (or cyber) insecure, as well as prone to power transmission congestion and consequent failures. Recent efforts in building a smart grid system have focused on addressing the problems of global warming effects, rising energy-hungry demands, and risks of peak loads. One of the major goals of the new system is to effectively regulate energy usage by utilizing the backbone of the prospectively deployed Automatic Meter Reading (AMR), Advanced Meter Infrastructure (AMI), and Demand Response (DR) programs via the advanced distribution automation and dynamic pricing models. The function of the power grid is no longer a system that only supplies energy to end users, but also allows consumers to contribute their clean energy back to the grid in the future. In the meantime, communications networks in the electric power infrastructure enact critical roles. Intelligent automation proposed in smart grid projects include the Supervisory Control And Data Acquisition/Energy Management Systems (SCADA/EMS) and Phasor Management Units (PMU) in transmission networks, as well as the AMR/AMI associated with field/neighborhood area networks (FAN/NAN) and home area networks (HAN) at the distribution and end-use levels. This article provides an overview of the essentials of the progressive smart grid paradigm and integration of different communications technologies for the legacy power system. Additionally, foreseeable issues and challenges in designing communications networks for the smart grid system are also rigorously deliberated in this paper.

Linear motion electric power generator

Abstract: A linear motion electric power generator for generating electric current from work done by an intermittent force. A moving magnet (2) is confined so that it can move with bi-directional linear, or approximately linear, motion through each of at least two coils (5 and 6). The coils are spaced apart from each other and connected electrically so that current produced in a first coil as a result of movement of the moving magnet is substantially in phase with current produced in said second coil. Embodiments of the invention provide pwoer from extremely low power mechanical forces and are useful for providing power for long life flashlights, for alarm systems and for communication devices located at places where conventional electric power sources are unavailable. Another preferred embodiment is a low profile unit which derives its mechanical power from repetitive forces such as the forces on the heel of a shoe during walking or running.

Design for reliability of power electronic systems

Abstract: Advances in power electronics enable efficient and flexible processing of electric power in the application of renewable energy sources, electric vehicles, adjustable-speed drives, etc. More and more efforts are devoted to better power electronic systems in terms of reliability to ensure high availability, long lifetime, sufficient robustness, low maintenance cost and low cost of energy. However, the reliability predictions are still dominantly according to outdated models and terms, such as MIL-HDBK-217H handbook models, Mean-Time-To-Failure (MTTF), and Mean-Time-Between-Failures (MTBF). A collection of methodologies based on Physics-of-Failure (PoF) approach and mission profile analysis are presented in this paper to perform reliability-oriented design of power electronic systems. The corresponding design procedures and reliability prediction models are provided. Further on, a case study on a 2.3 MW wind power converter is discussed with emphasis on the reliability critical components IGBTs. Different aspects of improving the reliability of the power converter are mapped. Finally, the challenges and opportunities to achieve more reliable power electronic systems are addressed.

Electrical powered vehicle and power feeding device for vehicle

Abstract: An electrical powered vehicle includes a secondary self-resonant coil, a secondary coil, a rectifier, and a power storage device. The secondary self-resonant coil is configured to be magnetically coupled with a primary self-resonant coil of a power feeding device by magnetic field resonance, and allow reception of high frequency power from the primary self-resonant coil. The secondary coil is configured to allow reception of electric power from the secondary self-resonant coil by electromagnetic induction. The rectifier rectifies the electric power received by the secondary coil. The power storage device stores the electric power rectified by the rectifier.