Papers by Keyword: Maximum Power Point (MPP)

Abstract: The benefit of improving the efficiency of photovoltaic (PV) solar system has come into view because of increasing the demand for electricity, especially in the urban areas. However, these PV solar systems are vulnerable to the mismatch operating conditions. Under such conditions, the performance of solar cells has decreased rapidly since the nonuniform insolation hitting the cells and with different values. Then this leads to cause rapidly decreasing in the output power value and maximum power point, beside to hot spot points that may be occurring in the solar cell which finally leads to damage these cells. This paper proposes an optimal connection of substrings with different value of shadow conditions, based on a thorough configuration that can significantly reduce that nonuniform condition loss. The refinement over existing photovoltaic (PV) solar array interconnections is proven by extensive simulation results by using MATLAB SIMULINK.

Abstract: 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.

Abstract: Due to the different PV modules and external conditions, large-scale photovoltaic power plants often show a multi-peak PV characteristics. But the traditional MPPT methods is only for single-peak P-V curve to strike a maximum power point. So we need to improve the conventional MPPT methods. In the MATLAB/Simulink environment, we combined the Hysteresis Comparison Method with Incremental Conductance to build the S-function to create a simulation model obtaining the maximum power point power, voltage and current. In the same simulation system the traditional Incremental Conductance was used to obtain the maximum power, voltage and current which compare with the maximum power, voltage and current which obtained by the proposed method . The results of simulation illustrated the effectiveness of the proposed method .

Abstract: A derivation calculation methods for the maximum power point tracking is proposed in this paper. This method is the direct calculation method for the maximum power point tracking, through the calculation of the derivative value of the power to voltage, adjust the change values of occupies emptiescompared, which is used to deduce the voltage and current value, judge whether the derivative of the power to the voltage is zero, if it is ture, the maximum power point is got. Hardware is used the method to regulate the duty ratio of PWM in DC/DC boost circuit ,though once sampling, it can calculate the value of voltage and the duty ratio at maximum power point. The prototype experiments using DSP2812 chip verify that the inverter can better realize the most power tracing, high accuracy, and the system has the high stability.

Abstract: Considering the fact that when the cell temperature and solar insolation change rapidly, traditional variable step size(VSS) perturbation and observation(P&O) methods exist the defects that their tracking speed is relatively slow, there is small power oscillation around MPP(Maximum Power Point) and even some of them exist the situation of tracking unsuccessfully. This paper proposes a MPPT(Maximum Power Point Tracing) technology based on adaptive area algorithm. The simulation model of PV system is established by MATLAB. The simulation results show that the proposed method can track the MPP fast and accurately, and ensure the steady state characteristics of PV systems even when the climate conditions change rapidly. It effectively overcomes the defects of traditional variable step size perturbation and observation methods.

Abstract: Photovoltaic system performance is influenced by a variety of factors such as irradiance, temperature, shading, degradation, mismatch losses, soiling, etc. Especially shading, complete or partial, can have a significant contribution to the reduction of power output, depending mainly on the PV array configuration, the shading pattern and the existence of bypass diodes incorporated in the PV module design. In order to obtain the maximum power from a PV generator, it is of great importance to evaluate the complex effects of shading on the P-V and I-V curves.