Electric power

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

Electric power steering apparatus

Abstract: An electric power steering apparatus includes a charge-discharge circuit including a circuit charging an auxiliary power supply by turning on and off an MOS-FET for voltage boosting and that selectively configures a first output mode in which an electric power is supplied to a motor by a first electrical conduction path to which a voltage of a battery is applied or a second output mode in which the electric power is supplied to the motor by a second electrical conduction path to which a voltage of a source of the series-connected battery and auxiliary power supply is applied. When a failure of the battery is detected, the electric power steering apparatus connects the first conduction path to an electrical conduction path to ground by continuously holding the MOS-FET in an on-state and drives the charge-discharge circuit to select the second output mode, thereby configuring a circuit to supply the motor with the electric power only from the auxiliary power supply.

Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation

Abstract: Low-NOx NH3-air combustion power generation technology was developed by using a 50-kWe class micro gas-turbine system at the National Institute of Advanced Industrial Science and Technology (AIST), Japan, for the first time. Based on the global demand for carbon-free power generation as well as recent advances involving gas-turbine technologies, such as heat-regenerative cycles, rapid fuel mixing using strong swirling flows, and two-stage combustion with equivalence ratio control, we developed a low-NOx NH3-air non-premixed combustor for the gas-turbine system. Considering a previously performed numerical analysis, which proved that the NO reduction level depends on the equivalence ratio of the primary combustion zone in a NH3-air swirl burner, an experimental study using a combustor test rig was carried out. Results showed that eliminating air flow through primary dilution holes moves the point of the lowest NO emissions to the lesser fuel flow rate. Based on findings derived by using a test rig, a rich-lean low NOx combustor was newly manufactured for actual gas-turbine operations. As a result, the NH3 single fueled low-NOx combustion gas-turbine power generation using the rich-lean combustion concept succeeded over a wide range of power and rotational speeds, i.e., below 10–40 kWe and 75,000–80,000 rpm, respectively. The NO emissions were reduced to 337 ppm (16% O2), which was about one-third of that of the base system. Simultaneously, unburnt NH3 was reduced significantly, especially at the low electrical power output, which was indicative of the wider operating range with high combustion efficiency. In addition, N2O emissions, which have a large Global Warming Potential (GWP) of 298, were reduced significantly, thus demonstrating the potential of NH3 gas-turbine power generation with low environmental impacts.

A Review of Compensating Type Custom Power Devices for Power Quality Improvement

Abstract: With the deregulation of the electric power energy market, providing quality power has become an important concern of both power suppliers and customers. Efforts have been made to improve the power quality using passive filters, active power filters, hybrid filters and the new concept of custom power. This paper presents a comprehensive review of compensating custom power devices mainly DSTATCOM (distribution static compensator), DVR (dynamic voltage restorer) and UPQC (unified power quality compensator). It is aimed at providing a broad perspective on the status of compensating devices in electric power distribution system to researchers and application engineers dealing with power quality problems. Classified references presented in this paper would serve quick and useful applications.

Hybrid energy off highway vehicle propulsion circuit

Abstract: A system and method for retrofitting a propulsion circuit of an existing Off Highway Vehicle to enable the propulsion circuit to operate as a hybrid energy Off Highway Vehicle propulsion circuit. The hybrid propulsion circuit includes a primary power source, and a traction motor for propelling an Off Highway Vehicle in response to the primary electric power. The traction motor has a motoring mode of operation and a power dissipation mode of operation. The traction motor generates dynamic braking electrical power in the power dissipation mode of operation. An electrical energy storage system includes a chopper circuit coupled to an energy storage device. The storage device is responsive to the chopper circuit to selectively store electrical energy generated in the power dissipation mode. The storage system selectively provides secondary electric power from the storage device to traction motor to assist in propelling the Off Highway Vehicle during the motoring mode.

Mobile micro-grid power system controller and method

Abstract: Methods and control apparatus are presented for controlling supply of electrical power to a mobile micro-grid power system, in which a master controller automatically rebalances the micro-grid by activating and deactivating individual power supplies to preferentially activate non-fuel consuming power supplies and deactivate fuel consuming power supplies so as to minimize fuel consumption for the micro-grid power system.