scholarly journals Research on the Calculation Method of Distributed Photovoltaic Access Capacity Considering Harmonic Characteristics

2021 ◽  
Vol 2095 (1) ◽  
pp. 012020
Author(s):  
Junhu Su ◽  
Zhaoguang Yang ◽  
Xu Liu ◽  
Jingyu Yang ◽  
Minghua Jiang
Keyword(s):  
Calculation Method ◽  
Estimation Method ◽  
Kernel Density ◽  
Threshold Value ◽  
Photovoltaic System ◽  
National Standard ◽  
Grid Connection ◽  
Economic Operation ◽  
Capacity Calculation ◽  
Harmonic Emission Level

Abstract To raise the maximum access ability of the maximal distributed photovoltaic system, based on the metering terminal of plant and station system for many years, a nonparametric estimation method based on kernel density is proposed to calculate harmonic probability distribution, this paper proposes the calculation method of superposition index and simultaneous coefficient suitable for distributed photovoltaic grid-connection, and puts forward the capacity calculation method considering harmonic constraints. An example shows that the proposed method can increase the maximum admittance capacity by at least 15% compared with the traditional method under the condition that the harmonic emission level does not exceed the threshold value of national standard, and realize the safe, stable and economic operation.

The Research of a Derivation Calculation Method for the Maximum Power Point in Grid-Connect Photovoltaic System

2012 ◽  
Vol 588-589 ◽  
pp. 583-586
Author(s):  
Yu Xin Wang ◽  
Feng Ge Zhang ◽  
Xiao Ju Yin ◽  
Shi Lu Zhu
Keyword(s):  
Calculation Method ◽  
Maximum Power Point Tracking ◽  
Direct Calculation ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Duty Ratio ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

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.

scholarly journals Characteristic Analysis of Photovoltaic On-Grid System In Tropical Region For Weather-Corrected Performance Ratio Calculation Method Implementation

2018 ◽  
Vol 67 ◽  
pp. 01025
Author(s):  
Erfan Syahputra ◽  
Rio Agustian Fajarin ◽  
Eko Adhi Setiawan
Keyword(s):  
Temperature Coefficient ◽  
Calculation Method ◽  
Tropical Climate ◽  
Photovoltaic System ◽  
Performance Ratio ◽  
Ratio Method ◽  
Photovoltaic Systems ◽  
Subtropical Climate ◽  
Operating Condition ◽  
Real Operating Condition

Indonesia has different weather factors than the subtropical climate that influences the performance indicators of photovoltaic systems. One of them is performance ratio that is affected by temperature factors. NREL proposes calculation method of Weather-Corrected Performance Ratio for correcting factors (temperature) in calculation performance ratio of photovoltaic systems. However, the implementation of this method in real operating condition of photovoltaic system especially in the tropics, has not received special attention. In addition, temperature coefficient of power photovoltaic (δ) in Standard Test Condition, is used in the calculation method may be different in real operating condition. This study was conducted to determine the effects of weather-corrected performance ratio method and to know characteristic of temperature coefficient of power photovoltaic (δ) as factors in of weather-corrected performance ratio method, in real operating condition especially in tropics. Through analysis photovoltaic system data from the data logger it is found that the range values of weather-corrected performance ratio are greater than conventional methods, with a maximum increase of 2.43%. Moreover it is found that because average temperature of tropical climate is higher than subtropical climate, it makes the percentage of power decrease to rise in temperature (δ) in tropical climate is higher than subtropical climate.

scholarly journals An Empiric-Stochastic Approach, Based on Normalization Parameters, to Simulate Solar Irradiance

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Edith Osorio de la Rosa ◽  
Guillermo Becerra Nuñez ◽  
Alfredo Omar Palafox Roca ◽  
René Ledesma-Alonso
Keyword(s):  
Experimental Data ◽  
Solar Irradiance ◽  
Solar Power ◽  
Moving Average ◽  
Estimation Method ◽  
Synthetic Data ◽  
Stochastic Approach ◽  
Photovoltaic System ◽  
Fitting Procedure ◽  
Irradiance Data

This paper presents a methodology to estimate solar irradiance using an empiric-stochastic approach, which is based on the computation of normalization parameters from the solar irradiance data. For this study, the solar irradiance data were collected in a weather station during a year. Posttreatment included a trimmed moving average to smooth the data, the performance of a fitting procedure using a simple model to recover normalization parameters, and the estimation of a probability density, which evolves along the daytime, by means of a kernel density estimation method. The normalization parameters correspond to characteristic physical variables that allow us to decouple the short- and long-term behaviors of solar irradiance and to describe their average trends with simple equations. The normalization parameters and the probability densities allowed us to build an empiric-stochastic methodology that generates an estimate of the solar irradiance. Finally, in order to validate our method, we had run simulations of solar irradiance and afterward computed the theoretical generation of solar power, which in turn had been compared with the experimental data retrieved from a commercial photovoltaic system. Since the simulation results show a good agreement with the experimental data, this simple methodology can generate the synthetic data of solar power production and may help to design and test a photovoltaic system before installation.

scholarly journals Study on Flexural Bearing Capacity Calculation Method of Enclosure Pile with Partial Excision in Deep Foundation Pit

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Mingfeng Lei ◽  
Linghui Liu ◽  
Yuexiang Lin ◽  
Jin Li
Keyword(s):  
Flexural Strength ◽  
Bearing Capacity ◽  
Calculation Method ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Theoretical Derivation ◽  
Deep Foundation Pit ◽  
Practical Engineering ◽  
Capacity Calculation ◽  
Partial Excision

During deep foundation pit construction, the structural clearance intrusion, which is caused by the complex formation conditions and the inefficient drilling equipment, is usually detected due to the vertical deviation of piles. To meet construction requirements, pile parts intruding into the structural clearance are supposed to be excised. However, the sectional flexural strength of the pile is bound to decrease with partial excision, which would reduce the bearing capacity of the enclosing structure during construction. In this paper, a theoretical derivation of the normal sectional flexural strength of the partially excised circular pile is proposed. The derivation adopts the assumption of the plane section and steel ring equivalence and can be solved by the bisection method. Furthermore, the calculation method is applied to the pile evaluation of a practical engineering; also, the method is verified by the numerical method. The application results show that the excision of rebar and pile’s sectional area will cause a rapid linear decline in the sectional flexural strength. After excising 18 cm radial thickness of the circular pile (ϕ800 mm) and 6 longitudinal rebars, the sectional flexural strength of the pile decreases to 58% from the origin, which cannot meet the support requirement. The analysis indicates that pile reinforcements must be carried out to maintain the construction safety.

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