scispace - formally typeset
Search or ask a question

Showing papers on "Power optimizer published in 1985"


Patent
26 Sep 1985
TL;DR: In this paper, a system for converting DC electrical solar generated energy to AC electrical energy is described, where a DC motor is driven by electricity obtained from DC electrical energy producing solar panels and an air compressor is used to provide a constant flow of air to a submerged cross-flor turbine.
Abstract: A system for converting DC electrical solar generated energy to AC electrical energy. A DC motor is driven by electricity obtained from DC electrical energy producing solar panels. The DC motor drives an air compressor which in turn provides, via Archimedes' principle, a constant flow of air to a submerged cross-flor turbine. The turbine is rotated by the rising air bubbles through the water. An AC generator is connected to the shaft of the turbine. The output of the AC generator is connected to the shaft of the turbine. The output of the AC generator is then fed to the consumer's or homeowner's electrical supply lines. Special cleaning means removes impurities from the air flowed through the cross-flow turbine.

27 citations


Patent
Shigeta Ueda1, Mitsuyuki Hombu1, Honda Kazuo1, Akiteru Ueda1, Katsunori Suzuki1, Seiya Shima1 
21 Oct 1985
TL;DR: In this paper, a three phase AC-DC converter composed of self-extinction devices for converting an AC power furnished from an three-phase AC power source into a DC power and a DC-AC inverter connected with the ACDC converter through a DC reactor for re-converting the DC power into a 3 phase AC power to supply the reconverted power for a load.
Abstract: A current-source power converting apparatus having a three phase AC-DC converter composed of self-extinction devices for converting an AC power furnished from an three phase AC power source into a DC power and a DC-AC inverter connected with the AC-DC converter through a DC reactor for re-converting the DC power into a three phase AC power to supply the re-converted power for a load. When the failure of the AC power source is detect according to one embodiment, the AC power source is detached from the AC-DC converter and a battery is connected between arbitrary two phases at the input end of the AC-DC converter. After that, the DC power of the battery is supplied for the DC-AC inverter intermittently by switching the corresponding self-extinction devices of the AC-DC converter and controlled by varying the duty ratio of the switching operation.

23 citations


Patent
Kenji Umezu1
22 May 1985
TL;DR: In this paper, a frequency converting device is provided with a converter for converting ac input power into dc power, and an adjustment device for adjusting an output waveform of the inverter in accordance with the voltage values of the input power.
Abstract: A frequency converting device is provided with a converter for converting ac input power into dc power. The device includes an inverter for inverting an output (dc power) of the converter into an ac output power, and adjustment device for adjusting an output waveform of the inverter in accordance with the voltage values of the ac input power. The adjustment device comprises a memory which stores adjustment data corresponding to the voltage value of the ac input power source connected to the converter, and a selector for selecting a certain adjustment data from the memory in accordance with the voltage value of the ac input power to which the device is connected. Thus, even when the voltage of the ac input power is changed, the effective output of the inverter can be kept substantially constant by adjusting on/off times of the switching elements constituting the inverter to vary a duty factor of the inverter output.

23 citations


Patent
08 Nov 1985
TL;DR: In this article, the rotor of a wind turbine is provided with photovoltaic cells and pitch varying means and tracking means for turning the turbine to face the sun or into wind may be provided.
Abstract: In order to utilise both wind and solar energy the rotor of a wind turbine is provided with photovoltaic cells 19. The turbine may be of an axial flow type (Fig. 1) or vertical axis type (Fig. 2). Pitch varying means and tracking means for turning the turbine to face the sun or into wind may be provided. The turbine can be used on the roof of light cars or on the roofs of buildings for such purposes as airconditioning or refrigeration and it can also be used for irrigation, water pumping etc. In the case of the vertical axis device (Fig. 2) the rotor may be driven by an electric motor (18) powered by the cells (19) instead of the wind acting on vanes (16).

15 citations


Patent
29 Mar 1985
TL;DR: A power converter control apparatus includes an automatic power controller (APC) for controlling a rectifier (1A) and an automatic reactive power controller for controlling an inverter (1B) as mentioned in this paper.
Abstract: A power converter control apparatus includes an automatic power controller (APC) for controlling a rectifier (1A) and an automatic reactive power controller (AQC) for controlling an inverter (1B). The inverter (1B) is coupled via DC power transmission lines (3) to the rectifier (1A). An output (E44) from the automatic power controller (APC) is utilized to change a control angle (or margin angle) of the inverter (1B) if a DC current (ld) flowing through the DC power transmission lines (3) increases to exceed a rated current value of the apparatus, thereby allowing a stable power transmission.

12 citations


Journal ArticleDOI
TL;DR: In this article, a control strategy for an AC/DC/AC interface to smooth or limit wind farm output is investigated, and an optimal level to which the wind output should be limited is found in terms of the distribution of wind power output and the relative cost of the fast acting and base loaded units.
Abstract: A control strategy for an AC/DC/AC interface to smooth or limit wind farm output is investigated. The need to follow rapid power variation from uncontrolled wind farms with expensive gas turbines limits the amount of penetration of wind energy systems in existing utilities. An AC/DC/AC interface makes it possible to limit the power variations from the wind farm. An optimal level to which the wind output should be limited is found in terms of the distribution of wind power output and the relative cost of the fast acting and base loaded units. Using the optimal cutting point for the wind output each wind farm can be included in the economic dispatch calculation. The economic advantage of limiting wind power output is demonstrated on an example system. Using a hypothetical system it is shown that wind penetrations as high as 16.75% may be economical using the optimal strategy made possible by the AC/DC/AC interface.

9 citations


Patent
29 Aug 1985
TL;DR: In this article, an AC motor drive includes a power converter (10 to 53) which supplies current to a DC bus from three-phase power lines (4, 5, 6) by controlling line current such that it is substantially in-phase with the applied line voltages.
Abstract: An AC motor drive includes a power converter (10 to 53) which supplies current to a DC bus (3) from three-phase power lines (4, 5, 6). An inverter (2) drives the motor (1) from power delivered to the DC bus (3) and it regenerates power to the DC bus (3) when the motor (1) is decelerated. The power converter (10 to 53) in turn regenerates the power to the power lines (4, 5, 6) by controlling line current such that it is substantially in-phase with the applied line voltages. Current overload protection (60 to 64) is provided for the transistor switches (16 to 21) employed in the power converter bridge circuit.

3 citations


Patent
03 Apr 1985

2 citations


Proceedings Article
01 Oct 1985
TL;DR: In this paper, the authors consider alternate sources of power during commercial AC power failure, and present three common options: 1) a battery reserve normally ranging from three to eight hours of DC power.
Abstract: Considering alternate sources of power during commercial AC power failure, telephone engineers are faced with three common options: 1) A battery reserve normally ranging from three to eight hours of DC power. 2) A stand-by engine (usually a diesel engine or turbine) to provide AC power as substitute for commercial AC. 3) A combination of the first two options. Once reliability and office integrity criteria are satisfied, it is possible to vary the extent of options 1 and 2 to achieve the most cost effective combination without jeopardizing telephone service.

1 citations


01 Jun 1985
TL;DR: In this article, the authors proposed a modified unit commitment that schedules connection and disconnection of generating units in response to load, and a modified generation control is also proposed that controls steam units under automatic generation control, fast responding diesels, gas turbines and hydro units under a feed forward control, and wind turbine array output under a closed loop array control.
Abstract: This research project proposed a modified unit commitment that schedules connection and disconnection of generating units in response to load. A modified generation control is also proposed that controls steam units under automatic generation control, fast responding diesels, gas turbines and hydro units under a feedforward control, and wind turbine array output under a closed loop array control. This modified generation control and unit commitment require prediction of trend wind power variation one hour ahead and the prediction of error in this trend wind power prediction one half hour ahead. An improved meter for predicting trend wind speed variation is developed. Methods for accurately simulating the wind array power from a limited number of wind speed prediction records was developed. Finally, two methods for predicting the error in the trend wind power prediction were developed. This research provides a foundation for testing and evaluating the modified unit commitment and generation control that was developed to maintain operating reliability at a greatly reduced overall production cost for utilities with wind generation capacity.

1 citations