Showing papers on "Electric power published in 2008"

Cooling, heating, generating power, and recovering waste heat with thermoelectric systems.

Abstract: Thermoelectric materials are solid-state energy converters whose combination of thermal, electrical, and semiconducting properties allows them to be used to convert waste heat into electricity or electrical power directly into cooling and heating. These materials can be competitive with fluid-based systems, such as two-phase air-conditioning compressors or heat pumps, or used in smaller-scale applications such as in automobile seats, night-vision systems, and electrical-enclosure cooling. More widespread use of thermoelectrics requires not only improving the intrinsic energy-conversion efficiency of the materials but also implementing recent advancements in system architecture. These principles are illustrated with several proven and potential applications of thermoelectrics.

Power supply system of vehicle

Abstract: PROBLEM TO BE SOLVED: To provide a power supply system of a vehicle, which can reduce a decline in power performance of a vehicle when it uses a plurality of power supplies in a switching manner or can prevent an excessive current flow when switching the power supplies. SOLUTION: A power supply system of a vehicle is equipped with inverters 14 and 22 which are supplied with electric power from batteries BA, BB1 and BB2; a connecting section 39B for connecting either one of the batteries BB1 and BB2 selectively to the inverters 14 and 22 so as to supply electric power to them; an air conditioner 40 which is supplied with electric power from the battery BA. When the battery (BB1 or BB2) to be selected is changed, a controller 30 stops the operation of the air conditioner 40 temporarily until the change in the connecting section 39B is completed. COPYRIGHT: (C)2010,JPO&INPIT

Reliability Issues in Photovoltaic Power Processing Systems

Abstract: Power processing systems will be a key factor of future photovoltaic (PV) applications. They will play a central role in transferring, to the load and/or to the grid, the electric power produced by the high-efficiency PV cells of the next generation. In order to come up the expectations related to the use of solar energy for producing electrical energy, such systems must ensure high efficiency, modularity, and, particularly, high reliability. The goal of this paper is to provide an overview of the open problems related to PV power processing systems and to focus the attention of researchers and industries on present and future challenges in this field.

Design and New Control of DC/DC Converters to Share Energy Between Supercapacitors and Batteries in Hybrid Vehicles

Abstract: In this paper, the authors propose the supercapacitor integration strategy in a hybrid series vehicle. The designed vehicle is an experimental test bench developed at the laboratory of electrical engineering and systems (L2ES) in collaboration with the research in electrical engineering and electronics center of Belfort (CREEBEL). This test bench currently has two diesel motors (each connected to one alternator) and lead-acid batteries with a voltage rating of 540 V and a fluctuation margin between +12% and -20% of the rated voltage. The alternators are connected to the dc link by rectifiers. An original strategy of the supercapacitor integration in this vehicle with their control is presented to find a better compromise between the dimensions of the embarked devices, the share energy efficiency, the dynamics of the supply, and the electric power storage. The supercapacitor packs are made up of two modules of 108 cells each and present a maximum voltage of 270 V. The main objective is to provide a peak power of 216 kW over 20 s from supercapacitors to the dc link. Various topologies of dc/dc converters are presented with effective methodologies of electric power management in the hybrid vehicle.

Multifunctional portable electric apparatuses

Abstract: The invention relates to portable electric apparatuses of the kind comprising a tool (1) driven by an electric motor (2), and a battery (3) supplying the electric power necessary for the operation of said tool, characterised in that said portable electric apparatuses include a communication system enabling, on the one hand, the exchange of information relative to the type, the state and the operation of the tool and of the battery when connected together and, on the other hand, the adjusting if need be of the operation parameters of said tool based on the characteristics of said battery and/or the operation parameters of the battery based on the operation parameters of said tool.

Integrated wireless resonant power charging and communication channel

Abstract: A power delivery system wirelessly deliver electric power and a communication signal to a target device. The power delivery system includes a power transmitting unit having a power source operable to source alternating current power and a sending resonant coupling component operable to couple the alternating current power to a coil for wireless power transmission by a non-radiated magnetic field at a target resonant frequency. The power transmitting unit is capable of dynamically tuning the wireless power transmission to the target resonant frequency wherein the target resonant frequency is specified dynamically. A communication module couples to the power transmitting unit and is operable to couple the communication signal to the non-radiated magnetic field. Operations may include target device authentication, target resonant frequency information communication, billing, and device management.

Comparison of energy harvesting systems for wireless sensor networks

Abstract: Wireless sensor networks (WSNs) offer an attractive solution to many environmental, security, and process monitoring problems. However, one barrier to their fuller adoption is the need to supply electrical power over extended periods of time without the need for dedicated wiring. Energy harvesting provides a potential solution to this problem in many applications. This paper reviews the characteristics and energy requirements of typical sensor network nodes, assesses a range of potential ambient energy sources, and outlines the characteristics of a wide range of energy conversion devices. It then proposes a method to compare these diverse sources and conversion mechanisms in terms of their normalised power density.

Interdependency of Natural Gas Network and Power System Security

Abstract: This paper proposes an integrated model for assessing the impact of interdependency of electricity and natural gas networks on power system security. The integrated model incorporates the natural gas network constraints into the optimal solution of security-constrained unit commitment. The natural gas network is modeled by daily and hourly limits on pipelines, sub-areas, plants, and generating units. The application of fuel diversity (e.g., generating units with fuel switching capability) is presented as an effective peak shaving strategy for natural gas demand which could hedge price volatilities of natural gas and electric power. The proposed model can be used by a vertically integrated utility for the commitment and dispatch of generating units and the allocation of natural gas for the next day utilization. The proposed model can also be used for measuring the security of social services by modeling the interdependency of natural gas and electric power system infrastructures. If the proposed model is used by GENCOs, gas constraints will be submitted to electricity markets as energy constraints. Illustrative examples show the impact of natural gas supply infrastructure on the economic operation of a vertically integrated utility. The examples also discuss the impact of generating units with fuel switching capability on the power system security when the supply of natural gas is limited.

Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System

Abstract: This paper introduces an energy management strategy based on fuzzy logic supervisory for road electric vehicle, combining a fuel cell power source and two energy storage devices, i.e., batteries and ultracapacitors. The control strategy is designed to achieve the high-efficiency operation region of the individual power source and to regulate current and voltage at peak and average power demand, without compromising the performance and efficiency of the overall system. A multiple-input power electronic converter makes the interface among generator, energy storage devices, and the voltage dc-link bus. Classical regulators implement the control loops of each input of the converter. The supervisory system coordinates the power flows among the power sources and the load. The paper is mainly focused on the fuzzy logic supervisory for energy management of a specific power electronic converter control algorithm. Nevertheless, the proposed system can be easily adapted to other converters arrangements or to distributed generation applications. Simulation and experimental results on a 3-kW prototype prove that the fuzzy logic is a suitable energy management control strategy.

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.

Power Electronics in Smart Electrical Energy Networks

Abstract: Introduction Principles of Electrical Power Control Overview of Power Electronics Converters and Controls Quality Problems in Smart Networks EMC Cases in Distributed Electrical Power System High Frequency AC Power Distribution Platforms Integration of Distributed Generation with Electrical Power System Active Power Quality Controllers Energy Storage Systems Variable and Adjustable Speed Generation Systems Grid Integration of Wind Energy Systems Grid Integration of Photovoltaics and Fuel Cells

Online Energy Management for Hybrid Electric Vehicles

Abstract: Hybrid electric vehicles (HEVs) are equipped with multiple power sources for improving the efficiency and performance of their power supply system. An energy management (EM) strategy is needed to optimize the internal power flows and satisfy the driver's power demand. To achieve maximum fuel profits from EM, many solution methods have been presented. Optimal solution methods are typically not feasible in an online application due to their computational demand and their need to have a priori knowledge about future vehicle power demand. In this paper, an online EM strategy is presented with the ability to mimic the optimal solution but without using a priori road information. Rather than solving a mathematical optimization problem, the methodology concentrates on a physical explanation about when to produce, consume, and store electric power. This immediately reveals the vehicle characteristics that are important for EM. It is shown that this concept applies to many existing HEVs as well as possible future vehicle configurations. Since the method only focuses on typical vehicle characteristics, the underlying algorithm requires minor computational effort and can be executed in real time. Clear directions for online implementation are given in this paper. A parallel HEV with a 5-kW integrated starter/generator (ISG) is selected to demonstrate the performance of the EM strategy. Simulation results indicate that the proposed EM strategy exhibits similar behavior as an optimal solution obtained from dynamic programming. Profits in fuel economy primarily arise from engine stop/start and energy obtained during regenerative braking. This latter energy is preferably used for pure electric propulsion where the internal combustion engine is switched off.

Business methods in a power aggregation system for distributed electric resources

Abstract: Systems and methods are described for a power aggregation system. In one implementation, a method includes determining a level of renewable energy on a power grid, determining a price of electricity on the power grid, and scheduling a charging of an electric resource connected to the power grid as a function of the price of electricity on the power grid and the level of renewable energy on the power grid.

Demand Response model considering EDRP and TOU programs

Abstract: Demand side management (DSM) is one of the most important methods which has been used to maximize the benefits of the electric power market participants. In the deregulated power systems, DSM is called demand response (DR). In this paper, two DR programs have been focused: time-of-use (TOU) and emergency demand response program (EDRP). In this paper DR is modeled considering both TOU and EDRP methods, simultaneously, using the single and multi period load models, based on the load elasticity concept. The proposed model is implemented on the peak load of the Iranian power grid and the optimum prices for TOU program and the optimum incentives for combined TOU and EDRP programs are determined.

Impact assessment of plug-in hybrid vehicles on pacific northwest distribution systems

Abstract: The U.S. electric power infrastructure is a significantly underutilized strategic asset which, with the proper shift in operational paradigms could provide a significant portion of the energy requirements for the existing U.S. light duty vehicle (LDV) fleet. This shift would result in reduced emissions, improved economics for utilities, and a reduced dependence on oil. A previous study has shown that the existing generation and transmission assets of the U.S. electric power infrastructure could feasibly supply the electricity for approximately 70% of the U.S. LDV fleet. In the limitations of the distribution system were not explicitly addressed and are more difficult to quantify because of the large diversity of distribution systems topology, design guidelines and load growth. This paper focuses on the impacts of a high penetration of plug-in electric hybrid vehicles (PHEVs) on the distribution systems. Presented are results specific for the Pacific Northwest.

Power Distribution Monitoring System And Method

Abstract: A power distribution monitoring system includes a number of power line mounted monitors. Each monitor can acquire data regarding the delivery of electrical power in the power line, wirelessly transmit and receive messages, and electromagnetically acquire and store operating electrical power from electrical current flowing in the power line. The system also includes an aggregator that can wirelessly transmit and receive messages and wirelessly output beacon messages. In response to beacon signals wirelessly output by the aggregator, each monitor co-acts with the aggregator to dynamically build a wireless communication network for the wireless communication of the data acquired by the monitor regarding the delivery of electrical power in the power line to the aggregator.

Multi power sourced electric vehicle

Abstract: An inductive power transfer (IPT) pad and system for the charging of electric and hybid electric vehicles. The batter of such a vehicle can be selectively coupled to a high power electrical supply for fast charging or a lower power electrical supply for charging using IPT. The batteries of the vehicles are used in a system to control the load demand in an electricity network through variations of the frequency of power supplied.

Versatile apparatus and method for electronic devices

Abstract: An electronic system which includes a power delivery surface that delivers electrical power to an electrical or electronic device. The power delivery surface may be powered by any electrical power source, including, but not limited to: wall electrical outlet, solar power system, battery, vehicle cigarette lighter system, direct connection to electrical generator device, and any other electrical power source. The power delivery surface delivers power to the electronic device wirelessly. The power delivery surface may deliver power via a plurality of contacts on the electrical device conducting electricity from the power delivery surface, conductively coupling the electronic device to the power delivery surface, inductively coupling the electronic device to the power delivery surface, optically coupling the electronic device to the power delivery surface, and acoustically coupling the electronic device to the power delivery surface as well as any other electrical power delivery mechanism.

Power grids vulnerability: a complex network approach

Abstract: Power grids exhibit patterns of reaction to outages similar to complex networks. Blackout sequences follow power laws, as complex systems operating near a critical point. Here, the tolerance of electric power grids to both accidental and malicious outages is analyzed in the framework of complex network theory. In particular, the quantity known as efficiency is modified by introducing a new concept of distance between nodes. As a result, a new parameter called net-ability is proposed to evaluate the performance of power grids. A comparison between efficiency and net-ability is provided by estimating the vulnerability of sample networks, in terms of both the metrics.

Advancement of energy storage devices and applications in electrical power system

Abstract: Overall structure of electrical power system is in the process of changing. For incremental growth, it is moving away from fossil fuel based operations to renewable energy resources that are more environmentally friendly and sustainable. At the same time it has to grow to meet the ever increasing need for more energy. These changes bring very unique opportunities and obstacles. Over the past few decades many new and innovative ideas have been explored in the broad area of energy storage. They range in size, capacity and complexity in design. Some of the systems are designed for applications in large scale power and others are performing short term energy storage ride through capabilities for critical manufacturing and technology systems. Energy storage technology has become an enabling technology for renewable energy applications and enhancing power quality in the transmission and distribution power systems. This paper summarizes all the advancements made and provide a composite picture of costs and trends in storage technologies.

Electric power supply system and vehicle

Abstract: An electric automobile has a battery and also has a travel motor and a vehicle interior load device which operate using electric power from the battery. In response to a request for a start of electric power supply to the vehicle interior load device with the automobile being at a standstill, the electric automobile determines, based on the charged state of the battery, whether electric power from the battery can be supplied to the vehicle interior load device. When determining that the electric power from the battery cannot be supplied to the vehicle interior load device, the electric automobile makes a request to an electric power supply device to supply electric power to the vehicle interior load device. In response to the request, the electric power supply device electrically connects to the vehicle interior load device and starts supply of electric power to the vehicle interior load device.

Wireless power transfer using magneto mechanical systems

Abstract: Wireless power transfer is received using a magneto mechanical system. Movement of the magneto mechanical system is converted to electric power.

Power distribution, management, and monitoring systems and methods

Abstract: Managing electrical power usage in a power distribution system. Power usage data indicative of electrical current flow through electrical outlets in the system are collected and displayed for a user. The user may select an outlet and issue a command to control current flow through that outlet. Environmental data may also be collected and displayed. Outlets in different Cabinet Power Distribution Units (CDUs) in different locations may be clustered for reporting and control. A database structure provides a “system” table for data descriptive of the system, a “tower” table for data descriptive of outlets and other elements in the system, an “infeed” table for data descriptive of input electrical power, and an “outlet” table for data descriptive of electrical power flowing through the outlets.

Apparatus, system, and method to manage the generation and use of hybrid electric power

Abstract: An apparatus, system, and method are disclosed to manage the generation and use of hybrid electric power. A monitoring module 202 receives signals from one or more sensors 116. The signals comprise power level information of an electric energy storage device, power level information of one or more energy converters 102/104, and power level information of an electric load. A determination module 204 compares the signals to determine whether electric power from the energy converters 102/104 satisfies the electric load. A regulation module 206 adjusts the electric power from the energy converters 102/104 in response to a determination by the determination module 204 that the electric power from the energy converters 102/104 does not satisfy an electric load threshold.