Power optimizer

About: Power optimizer is a research topic. Over the lifetime, 10525 publications have been published within this topic receiving 199245 citations.

Modeling the grid synchronization induced negative-resistor-like behavior in the output impedance of a three-phase photovoltaic inverter

Abstract: Photovoltaic power has to be converted from DC into AC in grid-connected applications. The conversion is done by using a single or three-phase inverter. Phase angle and frequency of the injected current and the grid voltage have to match to achieve unity power factor. This has been commonly accomplished by using a phase-locked-loop (PLL). The PLL has a tendency to make the output impedance of the inverter to appear as a negative resistor which can introduce harmonics in the grid current or even make the inverter-grid interface unstable. This paper presents a general small-signal model of a PV inverter in the synchronous reference frame which includes the PLL. Due to the negative resistance, the inverter can become unstable when the grid has high inductance. The derived small-signal model can be used to predict the exact conditions where the instability will take place by utilizing the impedance ratio and Nyquist stability criterion.

Power converter with controller operable in selected modes of operation

Abstract: A power converter and method of controlling the same for selected modes of operation. In one embodiment, the power converter includes a first power switch coupled to a source of electrical power and a second power switch coupled to the first power switch and to an output terminal of the power converter. The power converter also includes a controller configured to control an operation of the first and second power switches during selected modes of operation.

Power Converters, Control, and Energy Management for Distributed Generation

Abstract: Distributed generation (DG) is expected to play a vital role in the future to improve the quality of human life. DG and its integration to the local AC grid provide options for economical, continuous, and bidirectional power flow (utility interface). In addition, it provides a back-up to support during grid failure or blackouts. Extensive promotion of the DC grid is also proposed for the future to facilitate easy integration of renewable resources. Low-voltage DC grid derived from DG is safe and may cover a significant portion of residential load, which is mostly DC load avoiding inefficient AC/DC power supply. Vehicles in the smart grid have introduced a concept of living and mobility, i.e., sustainable living and low carbon mobility and are foreseen as a part of future microgrid. Research is needed to push and commercialize these technologies to make the environment clean by replacing conventional generation systems. This “Special Section on Power Converters, Control, and Energy Management for Distribution Generation” of the IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, is a step forward to promote and encourage extensive investigations in the areas associated with DG. In all, 16 papers were selected, which have one or more very unique features for the proposed applications. The topics range from new high gain DC/DC converters to inverters for solar PV integration on one side and development of effective test bed to brushless generation systems for potential DG applications on the other. To facilitate an in-depth survey of the published papers, the Guest Editors will now examine one by one the different contributions by highlighting the most noteworthy developments and findings.

A photovoltaic power output-utilizing device

Abstract: Briefly described, the invention provides a photovoltaic assembly power output utilizing device which partially charges a capacitor assembly. This capacitor assembly is then partially discharged by a DC/DC power converter in different ranges of voltages in which the power output from the photovoltaic assembly peaks for different light intensities.

Power over ethernet battery backup

Abstract: An apparatus, system, and method for providing DC battery backup power to Power over Ethernet, (PoE) Mid Span or End Point Power Sourcing Equipment, (PSE), such that in the event of the loss of utility power the PSE device is able to continue to provide power for some time while battery capacity remains. The apparatus includes an AC to DC converter that receives an AC power input and outputs DC power to the power over Ethernet circuitry and a DC battery pack that provides backup DC power to the power over Ethernet circuitry.