Power optimizer

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

A Power Smoothing System Based on Supercapacitors for Renewable Distributed Generation

Abstract: With the increasing share of renewable power sources in distribution networks, a smooth delivery of the power generated has become a relevant requirement for ensuring proper power quality. This paper presents a simple power smoothing strategy based on supercapacitors for power conditioning of distributed renewable generation. The power smoothing controller generates the power reference for the dc/dc converter, which has a power tracking control implemented with sliding-mode techniques. The proposed strategy consists of a voltage controller capable of maintaining the optimal state of charge and reducing high-frequency components of the power coming from renewable energy sources. A generalization of the PI structure is used to ensure simple design and implementation. With the proposed control structure, tuning is reduced to find a state feedback gain based on a pole placement criterion. In addition, a criterion for selecting supercapacitors' size is provided. The effectiveness of the proposed power smoothing scheme is evaluated by simulations and validated in an experimental platform.

System and method for controlling effective wind farm power output

Abstract: A method for controlling variability in power output of a wind farm supplying power to a grid includes monitoring a power output level of the wind farm. The monitored power output level is compared to a target power output level. A command is issued to increase or decrease electrical power consumption by an electrolyzer system electrically coupled to the wind farm to maintain a net power output level by the wind farm based upon the comparison.

Photovoltaic module-mounted AC inverter

Abstract: A photovoltaic module-mounted AC inverter circuit uses one or more integrated circuits, several switches, solid dielectric capacitors for filtering and energy storage, inductors for power conversion and ancillary components to support the above elements in operation. The integrated circuit includes all monitoring, control, and communications circuitry needed to operate the inverter. The integrated circuit controls the switches in both an input boost converter and a single-phase or multi-phase output buck converter. The integrated circuit also monitors all power processing voltages and currents of the inverter and can take appropriate action to limit power dissipation in the inverter, maximize the available power from the associated PV module and shut down the inverter output if the grid conditions so warrant. The integrated circuit implements power line communications by monitoring the AC wiring for signals and generating communications signals via the same pulse-width modulation system used to generate the AC power.

Use of turbine inertia for power smoothing of wind turbines with a DFIG

Abstract: Fluctuating power is of serious concern in grid connected wind systems and energy storage systems are being developed to help alleviate this. This paper describes how additional energy storage can be provided within the existing wind turbine system by allowing the turbine speed to vary over a wider range. It also addresses the stability issue due to the modified control requirements. A control algorithm is proposed for a typical doubly fed induction generator (DFIG) arrangement and a simulation model is used to assess the ability of the method to smooth the output power. The disadvantage of the method is that there is a reduction in energy capture relative to a maximum power tracking algorithm. This aspect is evaluated using a typical turbine characteristic and wind profile and is shown to decrease by less than 1%. In contrast power fluctuations at intermediate frequency are reduced by typically 90%.

Utility-connected power converter for maximizing power transfer from a photovoltaic source while drawing ripple-free current

Abstract: This paper presents a power converter for coupling photovoltaic arrays to the utility grid. The converter draws a programmable, ripple-free DC current from the photovoltaic array and injects power into the grid at unity power factor. The programmable input current feature makes this converter ideal for use with maximum power point tracking technology. The proposed converter has an additional unique feature in that the internal dc link carries a large (approximately 25%) ripple voltage. Allowing a large ripple on the DC link reduces the required size of the link capacitor. This paper includes basic system information, analysis of filter requirements, controller design and preliminary hardware results.