Showing papers on "Power optimizer published in 1986"

Bi-directional buck/boost DC/DC converter

Abstract: A bi-directonal DC/DC converter includes a first power switch coupled to a first input/output of the converter, an energy storage element coupled to the first power switch, a second power switch coupled between the energy storage element and a second input/output of the converter and means for controlling the first and second power switches so that one of the power switches is opened while the other power switch is alternately opened and closed to transfer power from one input/output to the other input/output.

Static power conversion and apparatus having essentially zero switching losses

Abstract: A high efficiency power converter is achieved utilizing a resonant DC link between a DC source, such as a converter rectifying power from an AC power system, to a variable frequency voltage source inverter. A resonant circuit composed of an inductor and capacitor is connected to the DC power supply and to a DC bus supplying the inverter and is caused to oscillate stably at a high frequency to provide a uni-directional voltage across the DC bus which reaches zero volts during each cycle of oscillation of the resonant circuit. The switching devices of the inverter are controlled to switch on and off only at times when the DC bus voltage is zero, thereby eliminating switching losses in the inverter. The resonant circuit can be caused to oscillate utilizing pairs of switching devices in the inverter or a separate switching device across the capacitor, which again are caused to switch on and off only at times of zero voltage on the DC bus. For AC to AC conversion, enabling bi-directional power flow, the switching devices of the power source which converts AC power to DC power may have switching devices which are also switched only at the times of zero voltage so that switching losses in these devices is also minimized.

Hybrid generating system

Abstract: Prior types of generating systems for producing AC and DC output power have utilized integrated drive generators for producing the AC power and means for rectifying the AC power developed by the drive generator to produce the DC power. However, such types of systems encounter various disadvantages, including less than desirable reliability of the DC power, distortion in the AC power caused by rectification thereof to produce the DC power and reduced efficiency. In order to overcome these problems, a hybrid generating system according to the present invention comprises an AC power generating section (54, 56, 60, 62) driven by a prime mover (50) for generating AC output power and a DC power generating section (66, 68, 70, 72) independent of the AC power generating section, also driven by the prime mover (50) for generating the DC output power wherein each of the AC and DC power generating sections includes a permanent magnet generator (80). The AC and DC power generating sections may be provided in a common housing (100) to provide a compact hybrid generating system in which reliability and efficiency are increased and distortion in the AC output power caused by generation of the DC output power is eliminated

Characteristics of orthogonal-core type dc-ac converter and its application to a photovoltaic power system

Abstract: This paper reports the orthogonal-core type dc-ac converter and its application to a photovoltaic power system for connecting the solar cell array to an ac distribution line. In the system, a simple control circuit for tracking the maximum array power which varies with the solar radiation is presented. Good operating characteristics are obtained in the experimental photovoltaic power system.

Control of a variable-speed wind turbine generator

Abstract: This paper discusses the connection of a Darrieus wind turbine generator to a small AC network through a back-to-back DC link. The DC link serves as static frequency changer and provides a means for controlling the dynamics of the wind turbine. A modulation control is implemented to reduce the vibrations in the wind turbine shaft. The damping controllers are demonstrated on a three-phase real-time HVDC simulator capable of detailed modeling of the system studied.