Power optimizer

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

Analysis and Design of Grid-Connected Photovoltaic Systems With Multiple-Integrated Converters and a Pseudo-DC-Link Inverter

Abstract: An architecture of multiple-integrated converter modules sharing an unfolding full-bridge inverter with a pseudo dc link (MIPs) is proposed for grid-connected photovoltaic systems in this paper. The proposed configuration can improve the power conversion, the control circuit complexity, and the cost competitiveness. The proposed MIP is composed of distributed flyback dc-dc converters (DFCs) and an unfolding full-bridge inverter with an ac filter. The DFCs can eliminate the shading effect by using the individual maximum power point tracking. In conventional flyback-type single-phase utility-interactive inverters, discontinuous conduction mode and boundary conduction mode are popular because of the inherent constant current-source characteristics more desirable for grid connection and of the simple procedures for the controller design. However, the operating mode suffers from a large current stress of the circuit components, which leads to the low power efficiency. To avoid this, the DFCs operate under continuous conduction mode that allows reduced current stresses and increased power efficiency, as well as low material cost. The current control loop of the converters employs primary-side regulation contributing to improvement of dynamics as well as the cost reduction significantly due to the elimination of the high-linearity photocoupler device. Development of a new dc-current loop that maintains the level of dc-current injection into the grid within the levels stipulated by IEEE 1547 will be dealt as well. The performance validation of the proposed design is confirmed by experimental results of a 200-W hardware prototype.

Comparative study of maximum power strategy in wind turbines

Abstract: Power characteristics of wind turbines are nonlinear It is particularly true for Savonius vertical axis systems whose the provided power is very sensitive to the load Thus, controlling its operating is essential to optimise the energetic behaviour Several control strategies (maximum power point tracking) can be used for energy conversion If the wind turbine characteristic (Cp(/spl lambda/)) is supposed to be a priori known, it can be used for an optimal control of the torque, speed or of the output current On the contrary, if this characteristic is unknown, an operational seeking algorithm such as fuzzy logic has to be implemented Several structures are also possible following the AC-DC converter which can be a PWM converter or a simple diode bridge A comparative study of these control strategies and architectures is proposed in this paper The analysis is based on simulations and on some experiments

Solar power generation inverter device

Abstract: PROBLEM TO BE SOLVED: To improve the use efficiency of power at the time of independent operation and low output linking operation by stably executing the maximum power point tracking control in spite of the large change of sunshine. SOLUTION: A controller 19 receives a limit signal from a limit circuit 60 and limits a reference current value ID1* in the case of VD2L*

Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

Abstract: —A substantial growth of the installed photovoltaic systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking technique enables maximization of the energy production of photovoltaic sources during stochastically varying solar irradiation and ambient temperature conditions. Thus, the overall efficiency of the photovoltaic energy production system is increased. Numerous techniques have been presented during the last decade for implementing the maximum power point tracking process in a photovoltaic system. This article provides an overview of the operating principles of these techniques, which are suited for either uniform or non-uniform solar irradiation conditions. The operational characteristics and implementation requirements of these maximum power point tracking methods are also analyzed to demonstrate their performance features.

Stability analysis of maximum power point tracking (MPPT) method in wind power systems

Abstract: Variable-speed wind power systems are able to vary the rotor speed according to wind speed variation. The maximum power point tracking (MPPT) is the key to notably improve efficiency of such energy extraction systems. The characteristic power curve MPPT method is one of the popular MPPT methods. It does not need real-time wind speed measurement and by using the relationship between power and current, the reference current can be obtained easily. This paper presents the steady state and dynamic analyses of this MPPT method and proposes a single pole transfer function to describe the effect of variation of wind speed on the rotor speed. This is conducted by applying the small signal analysis on the turbine-rotor mechanical system. To verify the performances of wind turbine system, both simulation and experimental systems are implemented based on MPPT power control. By concentrating on step wind speed variation, all results - proposed theory, simulation and experiments - present good consistency.