Power optimizer

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

Wind speed sensorless maximum power point tracking control of variable speed wind energy conversion systems

Abstract: A maximum power point tracking (MPPT) controller for variable speed wind energy conversion system (WECS) is proposed. The proposed method, without requiring the knowledge of wind speed, air density or turbine parameters, generates at its output the optimum speed command for speed control loop of rotor flux oriented vector controlled machine side converter control system using only the instantaneous active power as its input. The optimum speed commands which enable the WE to track peak power points are generated in accordance with the variation of the active power output due to the change in the command speed generated by the controller. The concept is analyzed in a direct drive variable speed permanent magnet synchronous generator (PMSG) WECS with back-to-back IGBT frequency converter. Vector control of the grid side converter is realized in the grid voltage vector reference frame. Simulation is carried out in order to verify the performance of the proposed controller.

Control of Improved Full-Bridge Three-Level DC/DC Converter for Wind Turbines in a DC Grid

Abstract: This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter in a dc-grid system is presented. Finally, a small-scale IFBTL dc/dc converter prototype was built and tested in the laboratory, and the results verify the theoretical analysis.

Operation and Control-Oriented Modeling of a Power Converter for Current Balancing and Stability Improvement of DC Active Distribution Networks

Abstract: Future active distribution networks appear as a solution to the energy distribution challenges. In this context, dc systems show potential for reducing losses and electronic equipment costs. Power electronics is the main enabler to this initiative and strong research efforts are ongoing in order to find solutions and evaluate the benefits and requirements for the power converters to be applied in dc systems. There is evidence that bipolar dc networks are advantageous due to higher reliability and increased power transmission capability. In such a network, currents are typically unbalanced and, thus, increase feeder losses. Another challenge in dc active distribution networks is the overall voltage stability due to the presence of distributed energy resources and loads with their power electronics interfaces. This study proposes a power converter and its control principles, which is able to balance the currents in a bipolar dc network and improve its stability. Its operation principles, control-oriented modeling, and laboratory implementation are presented and verified through experiments.

Sequentially-controlled solar array power system with maximum power tracking

Abstract: A power and control architecture employing circuitry that sequentially regulate power flows from independent solar-array sources or a mixture of power sources providing power to a common load. The device may be used on a satellite with solar-array sources; however it may also be used on ground based systems. Stiff bus voltage regulation is obtained by tightly controlling the most recently activated power-processing channel while keeping the previously activated power-processing channels in the Maximum Power Tracking mode to supply maximum power to a common load. The remaining power-processing channels are turned off or operated in stand-by mode. In an alternative system, with primary design goal of uniform power sharing among solar-array sources, all solar array sources are activated with uniform power sharing at light load and, as load demand increases, sequentially controlled to operate in the Maximum Power Tracking mode one solar array source at a time as necessary.