Power optimizer

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

Grid-Connected Photovoltaic System With Power Factor Correction

Abstract: A combined grid-connection/power-factor-correction technique for a photovoltaic (PV) system is proposed in this letter. A maximum power point tracking dc/dc converter served as a charger for the battery bank. A bidirectional inverter is applied as a generator/discharger during daytime, supplying power to the load. The inverter can also be used as a charger to maintain the minimum required voltage level of the batteries when the PV power is insufficient. Experiments on a 1-kW PV system show satisfactory results of the power management and the unity power factor at the utility side.

Novel Integration of a PV-Wind Energy System With Enhanced Efficiency

Abstract: A novel integration scheme of solar photovoltaic (PV) with a large capacity doubly excited induction generator-based wind energy system is described. The proposed scheme uses both the grid- and rotor-side power converters of doubly fed induction generator to inject PV power into the grid. Thus, it renders a cost-effective solution to PV-grid integration by obviating the need for a dedicated converter for PV power processing. The system is able to feed significantly large PV power into the grid compared to an equivalent rating inverter used in the conventional PV-grid system. The proposed scheme prevents circulating power during subsynchronous operation during the availability of solar radiation. All these features enhance system efficiency. System stability is also augmented due to turbine inertia, facilitating high PV penetration into the power grid. The intermittent but complementary nature of solar PV and wind energy sources considerably improves the converters' utilization. Besides, the proposed scheme does not hamper maximum power point tracking of PV and wind sources except during very rarely occurring environmental glitches, which the PV power control algorithm is suitably geared to handle. A comprehensive system model is presented and used for designing the control strategy. The proposed scheme is supported by analysis, simulations, and experiments on a laboratory prototype.

Power control interface between a wind farm and a power transmission system

Abstract: A power control interface between an unstable power source such as a wind farm and a power transmission line employs an Electrical Energy Storage, Control System, and Electronic Compensation Module which act together like an 'electronic shock absorber' for storing excess power during periods of increased power generation and releasing stored energy during periods of decreased power generation due to wind fluctuations. The Control System is provided with a 'look ahead' capability for predicting power output (wind speed conditions) and maintaining energy storage or release over a 'narrow-band' range despite short duration fluctuations. The Control System uses data derived from monitoring the wind farm power output and the power transmission line, and employs system-modeling algorithms to predict narrow-band wind speed conditions. The power control interface can also use its energy storage capacity to provide voltage support at the point of injection into the power transmission system, as well as fault clearance capability for 'riding out' transient fault conditions occurring on the power transmission line.

Stochastic Coordination of Plug-In Electric Vehicles and Wind Turbines in Microgrid: A Model Predictive Control Approach

Abstract: To realize the synergy between plug-in electric vehicles (PEVs) and wind power, this paper presents a hierarchical stochastic control scheme for the coordination of PEV charging and wind power in a microgrid. This scheme consists of two layers. Based on the non-Gaussian wind power predictive distributions, an upper layer stochastic predictive controller coordinates the operation of PEV aggregator and wind turbine. The computed power references are sent to the lower layer PEV and wind controllers for execution. The PEV controller optimally allots the aggregated charging power to individual PEVs. The wind controller regulates the power output of wind turbine. In this way, a power balance between supply and demand in a microgrid is achieved. The main feature of this scheme is that it incorporates the non-Gaussian uncertainty and partially dispatchability of wind power, as well as the PEV uncertainty. Numerical results show the effectiveness of the proposed scheme.

Solar inverter and control method

Abstract: A power generation system including a photovoltaic (PV) module to generate direct current (DC) power is provided. The system includes a controller to determine a maximum power point for the power generation system and a boost converter for receiving control signals from the controller to boost the power from the PV module to a threshold voltage required to inject sinusoidal currents into the grid. A DC to alternating current (AC) multilevel inverter is provided in the system to supply the power from the PV module to a power grid. The system also includes a bypass circuit to bypass the boost converter when an input voltage of the DC to AC multilevel inverter is higher than or equal to the threshold voltage.