Showing papers on "Power optimizer published in 1989"

Power conversion system with stepped waveform inverter having prime mover start capability

Abstract: A power conversion system is operable in a generating mode to convert motive power developed by a prime mover into electrical power and in a starting mode to convert electrical power developed by a source of AC power into motive power for starting the prime mover. The system includes a rectifier having an output coupled to a DC link, first and second inverters, each coupled to the DC link and transformer including first and second sets of primary windings and a set of secondary windings wherein the second set of primary winding is coupled to an output of the second inverter. Contactors are provided for coupling the rectifier to the generator armature windings and the first set of primary windings to an output of the first inverter so that AC power produced by the generator is converted into DC power on the DC link and the DC power is converted into fixed frequency AC power which is developed in the set of secondary windings. The contactors are operable in the starting mode to couple the source of AC power to the set of secondary windings, the first set of primary windings to the rectifier and the output of the first inverter to the generator armature windings so that the AC power induced in the first set of primary windings due to application of AC power to the set of secondary windings is converted into DC power on the DC link and the DC power is converted into AC power at a controlled voltage and frequency which is applied to the generator armature windings.

Power converter and method of controlling the same

Abstract: A power converter converts AC input power into AC output power to which a load is connected. This power converter comprises a controller for controlling power converting operation of the power converter, a DC voltage detector for detecting a DC voltage of the DC power to provide a DC voltage signal, a first reference generator for generating a first reference, an output detector for detecting a condition of the AC output power to provide an output condition signal, a second reference generator for generating a second reference in response to the output condition signal, a condition detector for detecting a condition of the AC input power to provide an output condition signal, and a selector for supplying the second reference to the controller when the input condition signal is provided.

No break power transfer control for a vscf power generating system

Abstract: In aircraft applications, it may be necessary or desirable to transfer one or more loads between a variable speed, constant frequency (VSCF) power generating system and a further source of AC power. Prior controls for effecting such transfer, however, have been unduly complex. In order to overcome this problem, a control (30) for a VSCF system (10) senses the deviation of a parameter of the power developed by an inverter (22) of the system (10) relative to a parameter of the power developed by an AC power source (28) and controls the inverter (22) in accordance with such deviation to cause the parameter of the power developed thereby to approach the parameter of the power developed by the AC power source (28). The inverter (22) and the AC power source (28) are connected in parallel across one or more loads (27) when the parameter deviation is within a certain range. Either the inverter (22) or the AC power source (28) is thereafter disconnected a certain time after the two were connected in parallel to complete the power transfer.

Electromagnetic cooker including load control

Abstract: In an electromagnetic cooking apparatus, low heating power control is carried out by turning ON/OFF a DC power supply circuit, or rectifier circuit, at a commercial frequency lower than an inverting frequency of DC/AC inverter. The electromagnetic cooking apparatus includes: a DC (direct current) power supply for producing DC power from low-frequency AC (alternating current) power; a DC-to-AC inverting circuit coupled to the DC power supply and including a switching element and also a heating coil, for inverting the DC power inputted from the DC power supply into high-frequency AC power so as to heat a metal pan by energizing the heating coil with the high-frequency AC power, thereby electromagnetically inducing eddy currents within the metal pan; a monitoring circuit for monitoring switching conditions of the switching element so as to output a switching condition signal; and an ON/OFF-controlling circuit for turning ON/OFF power supply operation of the DC power supply, or inverting operation of the DC/AC inverter circuit in response to the switching condition signal at a timing period defined by a time constant smaller than a thermal time constant determined by a heat capacity of a metal material of the pan.

Ac/dc powered microwave oven

Abstract: A microwave oven (22) for use on transports (10) where DC power (28) is available employs a first inverter (100) to generate internal AC power to operate the microwave components other than the magnetron (33). The internal AC power is passed with relatively low current through the oven interlocks (46, 48) to drive a power inverter (106) that delivers high voltage power to the magnetron (33). A relay (112) connected to sense when external AC power is available, causes an automatic switching that decouples the internal AC power from the power inverter (106) to enable conventional operation from external AC line power (24, 24'). When external AC line power (24, 24') is no longer applied, the microwave oven (22) automatically switches to operate from the available DC power (28). An efficient cooling fan is driven by a DC motor (35, 234). During a DC power mode, the DC power available at a center tap of the primary winding (206) of this transformer (208) is used to drive the DC motor (35, 234).

Pollution-free energy feeding system

Abstract: PURPOSE: To increase a generating amount per a unit area by high-efficiently collecting generating units utilizing natural energy, e.g. solar light, light collection heat collection postheat generation, a wind power, a wave power, tidal power, and installing the generating unit installed off-shore (in the vicinity of coastal line). CONSTITUTION: A power generating system utilizing solar light is constituted such that solar light 1 is collected to a heat pipe 3 by means of parabola reflection mirror 2, heat is transmitted to a high temperature tank 5, and a liquid metal 4 in the tank 5 is heated to approximate 600°C. Since an electrode 8 of a thermoelectric conversion element 7 at the lower part of the tank 5 is immersed in holding water 10 (cooled by sea water to a temperature of approximate 20°C) in a hydrogen manufacturing electrolytic cell 9, a high temperature difference is exerted on the element 7 to generate a power. In a wind power generating system, by receiving wind 12, the reflection mirror 2 itself is rotated, and the rotation force thereof is transmitted to a generator 14 through a gear 13. In a wave power generating system, a power is generated by vertical movement of. a floating body 9 on which the two solar light utilizing and the wind power generating systems are placed. In a tidal power generating system, an impeller 22 is rotated by means of a tidal current 21 to generate a power by a generator 23. The AC power thereof is regulated in a regulating device 35. COPYRIGHT: (C)1991,JPO&Japio

Wind-power flywheel integration

Abstract: A flywheel energy store is used to absorb fluctuations in the power output of a 55-kW wind turbine generator caused by wind turbulence. Both synchronous and asynchronous methods of linking the flywheel with the wind turbine are described. Wind power has been successfully harnessed on Fair Isle, Shetland, and now provides over 90% of the electricity to the community. The variation of wind speed and wind turbine power over a sample of 80-s periods is shown. Supply and demand are matched by a load control system involving frequency-dependent switching of domestic space- and water-heating loads. >

A new and fast tracking state estimator for multiterminal DC/AC power systems

Abstract: A new tracking state estimation algorithm is presented for integrated AC/DC power systems. The algorithm is based on the rectangular coordinate formulation of the power system network equations. The first and second order derivatives of the equations are used to develop a fast tracking state estimator. The proposed method is found to have very good tracking ability. Digital simulation results on a test integrated AC/DC system are presented. >

Designing a 1200 Watt multiple output modular power system with high power utilization for the workstation environment

Abstract: The design of a 1200 W multiple-output modular power system for the workstation environment is described. High power utilization (78% efficiency with 80% power factor) is achieved through the use of Victor modules and a passive power factor correction. Emphasis is on the design of the AC-to-DC unit and DC-to-DC converter board (Power System Eurocard) with its controller for use in the Apollo DN 10000 workstation. System considerations, design trade-offs, and problems encountered are described. Future considerations for further enhancements to performance are proposed. >

High power density dc/dc converter: Component selection and design

Abstract: Further work pertaining to design considerations for the new high power, high frequency dc/dc converters is discussed The goal of the project is the development of high power, high power density dc/dc converters at power levels in the multi-kilowatt to megawatt range for aerospace applications The prototype converter is rated for 50 kW at a switching frequency of 50 kHz, with an input voltage of 200 Vdc and an output of 2000 Vdc The overall power density must be in the vicinity of 02 to 03 kg/kW

Photovoltaic Power System Using an Orthogonal-Core Type Push-Pull Converter and Characteristics of a Push-Pull Parametric Transformer

Abstract: The authors earlier proposed an orthogonal-core type push-pull converter. The converter was constructed with a pair of orthogonal-cores whose primary sides were excited by square-wave choppers, and the converter had almost sinusoidal output current and high power factor. In this paper we report a photovoltaic power system using the push-pull converter. The test results obtained in the trial system indicate that the orthogonal-core type push-pull converter can be applicable to a practical photovoltaic power system. As another application, an orthogonal-core type push-pull parametric transformer is also described here. It was experimentally clarified that a low distorted input current and high input power factor are obtained in the push-pull parametric transformer.