Electric power

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

Cooperative transmission for meter data collection in smart grid

Abstract: Smart grid will become the next-generation electrical power system to provide reliable, efficient, secure, and cost-effective energy generation, distribution, and consumption. To achieve these goals, communications infrastructure and wireless networking will play an important role in supporting data transfer and information exchange in smart grid. In this article, the application of cooperative transmission for the meter data collection in smart grid is introduced. In a service area of smart grid, there are multiple communities composed of power consumption nodes (e.g., houses). The power consumption demand from the nodes is measured by a smart meter and transmitted to a meter data management system (MDMS) through the data aggregator unit (DAU) using wireless broadband access. The community invests in and deploys a relay station to perform relay transmission to improve the transmission rate and avoid congestion at the DAU. As a result, the MDMS will have complete and correct power demand data, which can be used to make better decisions on power supply. Since the communities in a service area of smart grid are rational, they will optimize the relay transmission strategy so that the total cost (i.e., power cost and transmission cost) is minimized. To analyze the relay transmission strategy of the community, the noncooperative game model is formulated, and the Nash equilibrium is considered as the solution. The proposed network architecture and analysis will be useful for the design and optimization of a wireless network for smart grid.

Thermoelectric waste heat recovery as a renewable energy source

Abstract: A thermoelectric converter is a solid-state heat engine in which the electron gas serves as the working fluid and converts a flow of heat into electricity. It has no moving components, is silent, totally scalable and extremely reliable. In the early 1960’s a requirement for autonomous long‐ life sources of electrical power arose from the exploration of space, advances in medical physics, deployment of marine and terrestrial surveillance systems and the exploitation of the earth’s resources in increasingly hostile and inaccessible locations. Thermoelectric devices employing radioactive isotopes as a heat source (Radioisotope Powered Thermoelectric Generators, referred to as RTGs) provided the required electrical power. Total reliability of this technology has been demonstrated in applications such as the Voyager space crafts with Voyager 1 passing into the Heliosheath some 8.3 billion miles from Earth on May 24th 2006. However, employing radioisotopes as sources of heat has remained restricted to specialised applications where the thermoelectric generator’s desirable properties listed above outweighed its relatively low conversion efficiency (typically 5%). The fivefold increase in the price of crude oil in 1974, accompanied by an increased awareness of environmental problems associated with global warming, resulted in an upsurge of scientific activity to identify and develop environmentally friendly sources of electrical power. Thermoelectric generation in applications, which employ waste heat as a heat source, is a totally green technology and when heat input is free, as with waste heat, the system’s generating power density is of greater importance than its conversion efficiency in determining the system’s economic viability. Over the past ten years or so effort has focused on developing thermoelectric generating systems which can recover waste heat from the human body, computer chips, automobile engines, and industrial utilities. In this paper the basic concepts of thermoelectric generation are outlined. An overview is presented of recent advances in the development of high performance thermoelectric materials, novel devices and applications, both macro and micro/nano. Finally, the potential of thermoelectric recovery of waste heat as a renewable energy source is assessed.

The Synthesis of Bottom-Up and Top-Down Approaches to Climate Policy Modeling: Electric Power Technologies and the Cost of Limiting U.S. CO2 Emissions

Abstract: In the U.S., the bulk of CO2 abatement induced by carbon taxes comes from electric power. This paper incorporates technology detail into the electricity sector of a computable general equilibrium model of the U.S. economy to characterize electric power’s technological margins of adjustment to carbon taxes and to elucidate their general equilibrium effects. Compared to the top-down production function representation of the electricity sector, the technology-rich bottom-up specification produces less abatement at a higher welfare cost, suggesting that bottom-up models do not necessarily generate lower costs of abatement than top-down models. This result is shown to be sensitive to the elasticity with which technologies’ generating capacities adjust to relative prices

Electric railway traction. Part 3. Traction power supplies

Abstract: Power is transmitted to electric railway locomotives and vehicles using DC or single-phase AC networks. The parallel development of traction technology in industrialised countries has led to a plethora of different electrification systems. This article covers the electrical engineering aspects of DC and single-phase AC traction power transmission systems.

Adaptive Control Strategy for Active Power Sharing in Hybrid Fuel Cell/Battery Power Sources

Abstract: Hybrid systems composed of fuel cells and batteries combine the high energy density of fuel cells with the high power density of batteries. A dc/dc power converter is placed between the fuel cell and the battery to balance the power flow between them and greatly increase the peak output power of the hybrid. This paper presents an adaptive control strategy for active power sharing in the hybrid power source. This control strategy can adjust the output current setpoint of the fuel cell according to the state-of-charge (or voltage) of the battery, and is applicable in two topologies of active fuel cell/battery hybrids. The control strategy is implemented in Simulink and then tested under arbitrary load conditions through simulation and experiments. Simulation and experimental results show that the adaptive control strategy is able to adjust the fuel cell output current to adapt to the charge state of the battery, and appropriately distribute the electrical power between the fuel cell and the battery. Experiments demonstrate the generality of the adaptive control strategy.