Proposed Maximum Power Point Tracking Method Research Articles

일사량 변동에 대응한 태양광발전시스템의 최대전력 추종기법 연구

Maximum Power Point Tracking (MPPT) method for Photovoltaic (PV) system is implemented in PV inveter and it generate the maximum electric power from PV cell. MPPT method has been studied to have high efficiency and high tracking speed. However, these studies are basically focused on the performance under fixed irradiance condition. Based on the typical Perturbation and Observation (P&O) method, this paper presents the research results on modified P&O method to have a better performance under varying irradiance condition. The modified P&O method can have a better performance under varying irradiance condition because the additional measurements during the MPPT control period are conducted. The proposed MPPT method is verified by using 250kW PV inverter under linearly varying irradiance condition according to EN 50530.

MPPT System for Photovoltaic Module Connected to Battery Adapted for Unstable Atmospheric Conditions Using VHDL-AMS

This paper presents a novel maximum power point tracking (MPPT) algorithm used in photovoltaic (PV) module connected to a storage battery. The main aim of this algorithm is to maximize the PV array output power by tracking continuously the maximum power point (MPP) which depends on atmospheric conditions (panel temperature and irradiance). The full system is composed of a PV array, a storage battery and an electronic boost-type DC–DC converter inserted between the PV array and the storage battery. The proposed MPPT control algorithm used to control the boost DC–DC converter is intended to lead the PV array power to its maximum point by keeping the PV array voltage stable with little deviation. The modeling of this system is realized using the novel concept of “functional prototyping” based on Very high speed integrated circuits Hardware Description language–Analog and Mixed Signal (VHDL-AMS) which can be particularly useful to design and redesign complex system with multi-technologic aspect, and to optimize strategies of control. The usefulness of the proposed MPPT algorithm has been fully verified by digital simulation using Simplorer software, where the obtained results show that the proposed MPPT method can improve PV power system performances noticeably in steady and dynamic states.

Wind Turbine Power Coefficient Analysis of a New Maximum Power Point Tracking Technique

A small-scale wind energy conversion system can track the maximum power point (MPP) based on a linear relationship between Vdc2 and Idc. Unlike conventional MPP tracking (MPPT) methods using a lookup table, an advanced technique is proposed based on this relationship as a variant of the perturb and observe (P&O) method. It not only has the advantages of the conventional P&O method but also has a faster tracking speed and better performance. This paper theoretically analyzes the possible power coefficient drop when using a linear relationship for MPPT and establishes that the turbine design can ensure that the possible power coefficient drop is small. The simulation results show that the analysis is precise. The validity and performance of the proposed MPPT method are confirmed by both simulation and experimentation.

A New Maximum Power Point Tracking Control Scheme in Photovoltaic Systems for Energy Saving

Maximum power point tracking (MPPT) control could significantly increase the overall reliability and conversion efficiency of grid-connected photovoltaic (PV) systems, so it can reduce energy loss in the photoelectric conversion. In this paper, a new MPPT (Zero Average Incremental Conductance) control algorithm is proposed. This method has the advantages of traditional IncCond MPPT. Moreover, it is stable against interference and not sensitive to system models. Therefore the proposed algorithm could be available and widely used in practical MPPT systems. A 200W grid-connected PV system prototype is built in lab. Experiment results verify the effectiveness of the proposed MPPT method.

Novel MPPT Schemes with Direct Duty Ratio Perturbation for Solar PV Systems

The Maximum Power Point Tracking (MPPT) is a very important function in a Solar Photovoltaic (SPV) system. While previous research has been focussed on optimizing the performance of the MPPT, there is further scope to improve upon the MPPT efficiency without compromising on the complexity of the MPPT technique in terms of the algorithm and hardware requirements. The research work presented in this paper aims to address this gap. The paper presents two novel MPPT schemes which are the proposed Perturb and Observe (P&O) and proposed Incremental Conductance (IC) methods based on two-step control and direct duty ratio perturbation. The proposed techniques are efficient, computationally less complex and hardware minimal than previous study in this field. For verification, simulation has been performed for extensive irradiation profiles of Standard Test Conditions (STC), rapidly changing and gradually changing insolation conditions which are representative of the boundary cases. Results of the proposed MPPT methods are compared with that of conventional MPPT methods. The results show that proposed MPPT schemes have excellent tracking efficiency and dynamic response with respect to previous research.

A novel ant colony optimization-based maximum power point tracking for photovoltaic systems under partially shaded conditions

In order to achieve maximum efficiency a photovoltaic (PV) arrays should operate at their maximum power point (MPP). Therefore, an MPP tracking (MPPT) scheme is implemented between the PV system and the load to obtain maximum power. When the irradiance distribution on the PV arrays is uniform, many traditional MPPT techniques can track the MPP effectively. However, when the PV arrays are partially shaded, multiple MPPs show up, which usually results in the failure of finding the global MPP. Some researchers have reported this problem and tried to solve it, but most of the MPP control schemes are relatively complicated or fail to guarantee the MPP under all shading circumstances. In order to overcome this difficulty, this paper presents a novel ant colony optimization (ACO)-based MPPT scheme for PV systems. A new control scheme is also introduced based on the proposed MPPT method. This heuristic algorithm based technique not only ensures the ability to find the global MPP, but also gives a simpler control scheme and lower system cost. The feasibility of this proposed method is verified with the irradiance of various shading patterns by simulation. In addition, the performance comparison with other traditional MPPT techniques, such as: constant voltage tracking (CVT), perturb and observe (P&O), particle swarm optimization (PSO), is also presented. The results show that the proposed algorithm can track the global MPP effectively, and is robust to various shading patterns.

Development of a Quick Dynamic Response Maximum Power Point Tracking Algorithm for Off-Grid System With Adaptive Switching (On–Off) Control of dc/dc Converter

This paper presents a new approach of Adaptive Search Control Method to perform maximum power point tracking (MPPT) in solar panels (SP). The suggested approach adapts the operation point (current I and voltage V) of the solar panel so quickly that it tracks MPP under the harshest environmental conditions by incorporating a flexible switching in a Boost dc/dc converter, which connects the photovoltaic (PV) panel to the load. The usage of a flexible switching control increases the dynamic response of MPPT and the efficiency of tracking. A dedicated simulink (matlab) model was developed for validation of the proposed MPPT method which was verified through multiple simulation conditions. Based on these results, the prototype system for evaluating the suggested method was developed and assembled. This prototype was developed on the base of a photonic integrated circuit (PIC) family microcontroller unit with an external circuit for accurate voltage and current measurements. The technical characteristics of the developed system (efficiency and tracking speed) have been verified experimentally with a 100 W c-Si solar panel under various environmental conditions. The results of measured and estimated MPPT efficiency were represented.

A Variable Step Size Incremental Conductance Direct MPPT Method for Stand-Alone PV Systems

This paper presents a variable step size incrementalconductance direct Maximum Power Point Tracking (MPPT) method using fuzzy membership for a standalone photovoltaic (PV) system under rapidly changing irradiation. MPPT techniques have been widely applied in PV systems to make a PV array generate maximum power, which depends on solar irradiation. In most applications of MPPT technologies, MPPT algorithm design methods are performed and tested under slowly changing atmospheric conditions such as irradiation and temperature. The short-term effect under rapidly changing irradiation should be considered, however, to improve the dynamic performance of PV system. Our proposed MPPT method is based on an incremental conductance algorithm with a direct control scheme that can directly adjust the duty cycle for the PI controller. A fuzzy membership function is adopted to determine the variable step size according to rapidly changing irradiation. The proposed methods thus has not only faster dynamic performance but also high tracking accuracy. In order to show the effect of the proposed method, the simulation model and proposed MPPT is designed with MATLAB/Simpower and simulated with MATLAB/Stateflow.

Photovoltaic dynamic MPPT on a moving vehicle

In addition to the conversion efficiency of a photovoltaic panel, the maximum power point tracking (MPPT) method also plays a central role to harvest most energy out of sun. The MPPT unit on a moving vehicle must keep tracking accuracy high in order to compensate rapid change of insolation due to dynamic motion of the vehicle. In this paper, some problems of a PV system associated with a moving vehicle are addressed, and a modified quadratic maximization MPPT algorithm is proposed. Theoretical PV performance is linked to the experimental test followed by the Sandia dynamic test protocol to verify the proposed MPPT method. Finally, experimental result on a model ship is discussed.

A Maximum Power Point Tracker with Automatic Step Size Tuning Scheme for Photovoltaic Systems

The purpose of this paper is to study on a novel maximum power point tracking (MPPT) method for photovoltaic (PV) systems. First, the simulation environment for PV systems is constructed by using PSIM software package. A 516 W PV system established with Kyocera KC40T photovoltaic modules is used as an example to finish the simulation of the proposed MPPT method. When using incremental conductance (INC) MPPT method, it usually should consider the tradeoff between the dynamic response and the steady-state oscillation, whereas the proposed modified incremental conductance method based on extension theory can automatically adjust the step size to track the maximum power point (MPP) of PV array and effectively improve the dynamic response and steady-state performance of the PV systems, simultaneously. Some simulation and experimental results are made to verify that the proposed extension maximum power point tracking method can provide a good dynamic response and steady-state performance for a photovoltaic power generation system.

An Intelligent Incremental Conductance MPPT Method for a Photovoltaic System

In this paper, a novel incremental conductance (INC) maximum power point tracking (MPPT) method based on extension theory is developed to make full use of photovoltaic (PV) array output power. The proposed method can adjust the step size to track the PV array’s maximum power point (MPP) automatically. Compared with the conventional fixed step size INC method, the presented approach is able to effectively improve the dynamic response and steady state performance of a PV system simultaneously. A theoretical analysis and the design principle of the proposed method are described in detail. Some simulation results are performed to verify the effectiveness of the proposed MPPT method.

A Real Maximum Power Point Tracking Method for Mismatching Compensation in PV Array Under Partially Shaded Conditions

Conventional popular maximum power point tracking (MPPT) methods are effective under uniform solar irradiance. However, under solar irradiance mismatching conditions [partially shaded conditions (PSCs)], these MPPTs can fail for real MPPT (RMPPT), because multiple local maxima can be exhibited on the power-voltage characteristic curve. Although some researchers have worked on RMPPT under partial shading conditions, the methods have some drawbacks in terms of complexity and requirements for additional circuits, etc. In this paper, a novel MPPT method capable of RMPPT under PSCs is proposed. The performance of the proposed MPPT method is analyzed according to the RMPP position and is verified by simulation and experimental results.

A novel multi-model neuro-fuzzy-based MPPT for three-phase grid-connected photovoltaic system

This paper presents a novel methodology for Maximum Power Point Tracking (MPPT) of a grid-connected 20 kW photovoltaic (PV) system using neuro-fuzzy network. The proposed method predicts the reference PV voltage guarantying optimal power transfer between the PV generator and the main utility grid. The neuro-fuzzy network is composed of a fuzzy rule-based classifier and three multi-layered feed forwarded Artificial Neural Networks (ANN). Inputs of the network (irradiance and temperature) are classified before they are fed into the appropriated ANN for either training or estimation process while the output is the reference voltage. The main advantage of the proposed methodology, comparing to a conventional single neural network-based approach, is the distinct generalization ability regarding to the nonlinear and dynamic behavior of a PV generator. In fact, the neuro-fuzzy network is a neural network based multi-model machine learning that defines a set of local models emulating the complex and nonlinear behavior of a PV generator under a wide range of operating conditions. Simulation results under several rapid irradiance variations proved that the proposed MPPT method fulfilled the highest efficiency comparing to a conventional single neural network and the Perturb and Observe (P&O) algorithm dispositive.

Design of a maximum power tracking system for wind-energy-conversion applications

A wind-generator (WG) maximum-power-point-tracking (MPPT) system is presented, consisting of a high-efficiency buck-type dc/dc converter and a microcontroller-based control unit running the MPPT function. The advantages of the proposed MPPT method are that no knowledge of the WG optimal power characteristic or measurement of the wind speed is required and the WG operates at a variable speed. Thus, the system features higher reliability, lower complexity and cost, and less mechanical stress of the WG. Experimental results of the proposed system indicate near-optimal WG output power, increased by 11%-50% compared to a WG directly connected via a rectifier to the battery bank. Thus, better exploitation of the available wind energy is achieved, especially under low wind speeds.