Electric power

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

Energy management system which includes on-site energy supply

Abstract: An energy management system includes one or more electric power generators (14) located at or near a consumer's premises (10), to provide power which is dedicated to the needs of that consumer The power provided by the on-site generators (14) complements that which is delivered via a centralized power grid network (12) In the event that the power grid (12) is disabled, or is otherwise unable to provide adequate power to the consumer (10), the on-site generators (14) are switched to provide power to critical equipment In one embodiment, a computer-driven control facility (18) selectively actuates the on-site generator (14) to intelligently arbitrage between the locally generated power and that which is provided via the grid network, based on a variety of factors The instantaneous cost of power supplied via the grid network is compared against stored costs of operating the on-site generators, such as the price of fuel required to run the generators, maintenance expenses, other types of service and installation expenses, and finance charges When these costs are less than the charges for the power provided by the grid network, the central control system actuates the on-site generators, to partially or totally replace power delivered via the grid Other factors are also employed in the decision whether to activate the on-site generators, such as data relating to weather conditions and peak usage periods Historical data regarding the consumer's power usage is employed to predict times when the usage requirements are likely to be high, and thereby actuate the generators to supplement or replace the power provided from the grid

Calorimetric Power Loss Measurement for Highly Efficient Converters

Abstract: The electrical determination of power losses by measuring the input and output power can reach sufficient accuracy for DC-DC converter systems, if well calibrated voltage meters and shunt resistors are applied. However, it is difficult to determine the power in AC-systems, especially with harmonics, due to phase-errors in the electric measurement. In addition, the electromagnetic interference (EMI) of switched-mode power supplies can disturb the electric power measurement. In this paper, the calorimetric determination of power converter system losses resulting in a high accuracy and which is almost immune against EMI phase errors, is described. The closed-type calorimeter is realized with a double-jacketed chamber which enables the power loss measurement between 10W and 200W for power converter systems of several kW. The resulting deviation of the implemented measurement system is less than ±0.4W, or ±0.05% at full load conditions (several kW), respectively, over the entire measurement range.

Load current management system for automotive vehicles

Abstract: An electrical power delivery system and method of operation particularly suitable for use in a vehicle is disclosed. A single wire power conductor is connected through remote power switches to a plurality of loads. The power conductor is sized such that its current-carrying capacity is less than the current required to simultaneously operate all the loads connected thereto. Logic means are provided for delivering a control signal to the remote power switches to selectively energize the appropriate loads. The logic means additionally includes means responding to excess current flow through the power conductor to schedule the control signals to prevent simultaneous operation of all the loads thereby limiting current flow through the power conductor to its current-carrying capacity.

Fixing device and image forming apparatus

Abstract: PROBLEM TO BE SOLVED: To secure proper printing quality, even at the beginning of printing by removing defects in fixing due to drop in the temperature of a fixing roller, at the start of the printing. SOLUTION: A fixing device comprises the fixing roller which fixes a toner image on a recording medium, a main power unit, a main heating body which is powered by the main power unit to heat the fixing roller, an auxiliary power unit which uses a specified charge storage means as a power source, an auxiliary heating body which is powered by the auxiliary power unit to heat the fixing roller together with the main heating body, an ambient temperature detecting means of detecting ambient temperature of the fixing roller, a time lapse measuring means of measuring the lapse of time, from the time the auxiliary power unit starts or stops supplying electric power to the auxiliary heating body in a heating stage at the start, and an auxiliary power supply controller which sets a period of power supply, from the auxiliary power unit to the auxiliary heating body at the start of printing, according to the detection result of the ambient temperature detecting means and the measurement result of the time lapse measuring means and restarts power supply. COPYRIGHT: (C)2007,JPO&INPIT