Power optimizer

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

Apparatus and methods for managing output power of strings of solar cells

Abstract: An apparatus and method that controls the power produced by a string of solar cells, enabling the string to operate at its maximum power point when connected to a bus that operates at an externally controlled voltage. The apparatus and method can also be used to increase or decrease the output power of a string to any desired operating point.

Neural MPPT of Variable-Pitch Wind Generators With Induction Machines in a Wide Wind Speed Range

Abstract: This paper proposes a maximum power point tracking (MPPT) technique for variable-pitch wind generators with induction machines (IMs), which can suitably be adopted in both the maximum power range and the constant-power range of the wind speed. To this aim, an MPPT technique based on the growing neural gas (GNG) wind turbine surface identification and corresponding function inversion has been adopted here to cover also the situation of variable-power region. To cope with the constant-power region, the blade pitch angle has been controlled on the basis of the closed-loop control of the mechanical power absorbed by the IM. The wind speed is then estimated in the constant-power region on the basis of the actual position of the blade pitch angle. The proposed methodology has been verified both in numerical simulation and experimentally on a properly devised test setup. In addition, a comparison between the proposed approach and the previously developed GNG-based MPPT has been performed on a real wind speed profile. Finally, the effect of the torsional stiffness of the mechanical transmission system has been analyzed.

Photovoltaic system and method for operating a photovoltaic system

Abstract: A photovoltaic system includes a plurality of photovoltaic modules and a DC motor connected to a three-phase generator driven by a shaft. The three-phase generator is connected to a power mains. The electric power supplied to the DC motor by the plurality of photovoltaic modules is repeatedly measured and adjusted, by changing an external excitation current of the DC motor, to the peak power attainable at the current ambient temperature and the current incident solar radiation intensity. The peak power is preferably determined by incrementally changing the excitation current in predetermined time intervals, until the supplied electric power produces a power level which can be regarded as the peak power.

Applying active network management schemes to an irish distribution network for wind power maximisation

Abstract: In order for governments worldwide to achieve their renewable targets, large amounts of new capacity, mainly wind power, need to be connected to power systems. A significant share is expected to be deployed at distribution levels. This paper is aimed at assessing the maximum wind power capacity a distribution network is able to integrate based on a multi-period AC Optimal Power Flow technique tailored to cater for Active Network Management schemes such as coordinated voltage control, adaptive power factor control and energy curtailment. The methodology is applied to an Irish 38kV circuit, considering the time-varying characteristics of demand and multiple wind generation profiles based on the coincident hours of different loading levels and wind power outputs over a year.

Power fluctuation smoothing apparatus and method for controlling distributed power supply system comprising the same

Abstract: PROBLEM TO BE SOLVED: To surely smooth fluctuation of output to a power system due to distributed power supply such as a wind power generation system and a solar power generation system by preventing shortage of power accumulation or full charging of a power accumulator. SOLUTION: A distributed power supply system 10 consisting of distributed power supply 9, a power fluctuation smoothing apparatus 1 and a power converter 15 is connected to a power system 12, a controller 4 of the power fluctuation smoothing apparatus 1 is composed of an output detector 5, an accumulated power detector 6, a target value setting device 7 for setting a target output value, and a charge/discharge controller 8 for controlling a charger/ discharger 3. An output of the distributed power supply 9 and amount of accumulated power of a power accumulator 2 are detected. A running average value in the preset period of an output of the distributed power supply 9 is compensated with an output target adjusting value which is preset depending on the amount of accumulated power to set an output target value to the side of the power system 12. When an output of the distributed power supply 9 is larger than the output target value, an extra power is used to charge the power accumulator 2. When an output is smaller than the output target value, shortage is compensated with the power discharged from the power accumulator 2 until the output to the side of power system 12 reaches the output target value. COPYRIGHT: (C)2002,JPO