Power optimizer

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

A new approach to obtain I-V and P-V curves of photovoltaic modules by using DC-DC converters

Abstract: The achievement of I-V and P-V curves of photovoltaic modules gives the possibility of obtaining their characteristic parameters: the short-circuit current (I/sub sc/), the open-circuit voltage (V/sub oc/), the maximum power point (MPP) and the fill factor (FF). These values are significant for the design of a photovoltaic system. These curves depend on the global irradiance (G), the temperature (T) and the spectral distribution of the solar irradiation. In this paper, a new methodology to determine the afore mentioned curves by using DC-DC converters is proposed. This methodology allows carrying out the complete sweep of the voltage and the current (including V/sub oc/ and I/sub sc/). Regarding the traditional methods, this new one provides the following advantages: a) minimum power loss with regard to the systems that operate in lineal zone (active zone); this implies several advantages in size and cost; and b) this new method allows an automatic adaptation of the interpolation interval.

Voltage-Oriented Input–Output Linearization Controller as Maximum Power Point Tracking Technique for Photovoltaic Systems

Abstract: This paper presents a robust input–output linearization controller as maximum power point tracking (MPPT) technique in a photovoltaic (PV) buck dc–dc converter with applications to dc microgrids, solar vehicles, or stand-alone systems. Due to the control structure proposed in this paper, the MPPT control system is able to track very fast irradiance changes. Meanwhile, the internal stability of the overall closed-loop system is guaranteed for different load scenarios. A sector condition is only required for the load current, which is satisfied for most of the current PV applications. In turn, this condition implies the robustness against oscillations in the dc bus voltage. Finally, the MPPT control system is validated through experimental results, where the closed-loop performance is evaluated under abrupt irradiance and set-point changes, parametric uncertainty, and dc bus load variations.

Enhanced Grey Wolf Optimizer based MPPT Algorithm of PV system under Partial Shaded Condition

Abstract: Partial shading condition is one of the adverse phenomena which effects the power output of photovoltaic (PV) systems due to inaccurate tracking of global maximum power point. Conventional Maximum Power Point Tracking (MPPT) techniques like Perturb and Observe, Incremental Conductance and Hill Climbing can track the maximum power point effectively under uniform shaded condition, but fails under partial shaded condition. An attractive solution under partial shaded condition is application of meta-heuristic algorithms to operate at global maximum power point. Hence in this paper, an Enhanced Grey Wolf Optimizer (EGWO) based maximum power point tracking algorithm is proposed to track the global maximum power point of PV system under partial shading condition. A Mathematical model of PV system is developed under partial shaded condition using single diode model and EGWO is applied to track global maximum power point. The proposed method is programmed in MATLAB environment and simulations are carried out on 4S and 2S2P PV configurations for dynamically changing shading patterns. The results of the proposed method are analyzed and compared with GWO and PSO algorithms. It is observed that proposed method is effective in tracking global maximum power point with more accuracy in less computation time compared to other methods. Article History : Received June 12nd 2017; Received in revised form August 13rd 2017; Accepted August 15 th 2017; Available online How to Cite This Article : Kumar, C.H.S and Rao, R.S. (2017 Enhanced Grey Wolf Optimizer Based MPPT Algorithm of PV System Under Partial Shaded Condition. Int. Journal of Renewable Energy Development, 6(3), 203-212. https://doi.org/10.14710/ijred.6.3.203-212

Operating and Loading Conditions of a Three-Level Neutral-Point-Clamped Wind Power Converter Under Various Grid Faults

Abstract: In order to fulfill the growing demands from the grid side, full-scale power converters are becoming popular in the wind turbine system. The low-voltage ride-through (LVRT) requirements may not only cause control problems but also result in overstressed components for the power converter. However, the thermal loading of the wind power converter under various grid faults is still not yet clarified, particularly at megawatt power level. In this paper, the impacts by three types of grid faults to a three-level neutral-point-clamped (3L-NPC) wind power converter in terms of operating and loading conditions are analytically solved and simulated. It has been found that the operating and loading conditions of the converter under LVRT strongly depend on the types/severity values of grid voltage dips and also the chosen control algorithms. The thermal distribution among the three phases of the converter may be quite uneven, and some devices are much more stressed than the normal operating condition.

Investigation of switched-mode rectifier for control of small-scale wind turbines

Abstract: This paper investigates the suitability and experimental testing of a simple power converter for a permanent magnet generator for use with a small-scale variable-speed wind turbine. The controller uses a switched-mode rectifier in conjunction with a high inductance generator that allows generator torque and power to be controlled via the switch duty-cycle. The controller maximises output power for wind speeds below rated, and limits turbine speed for higher wind speeds. Dynamometer and limited wind turbine test results are presented.