Estimation of power output of photovoltaic power generation on a ship using visual information

从能源和环境问题的角度出发，为了解决船舶上的光伏-柴油混合动力系统由于光伏功率的不规则性而出现的问题，已经进行了关于光伏（PV）功率估计的基础研究。主要研究成果包括：1.利用云层图像处理技术估算太阳能发电量（太阳辐照度）。首先，我们开发了一种利用机器视觉检测天空中主要影响太阳能发电量的云层运动，在几分钟内判断天气状况的基本方法，即“晴朗”或“多云”。接下来，考虑了一种估计几分钟内太阳辐射的方法。该方法基于对将要覆盖太阳的云的比率的分析。还利用全天空照相机研究了在较长时间（几个小时）内的太阳辐射估计。2.考虑太阳辐照度特性的太阳能光伏发电量（太阳辐照度）估算：根据太阳辐照度理论公式和实测太阳辐照度，设计了一种通过估算大气透过率来估算日太阳辐照度的方法。3.光伏-柴油混合发电系统的控制提出了利用上述光伏发电功率的短时和长时估计对光伏-柴油混合发电系统进行控制的基本方法，并将上述基础研究作为一个系统进行联合收割机的应用研究。

From the point of view of energy and environmental issues, basic researches on estimation of photovoltaic (PV) power have been carried out in order to solve the problems that occur to a PV-diesel hybrid system on a ship because of irregularity of the PV power. The results include :1.Estimation of PV power (solar irradiance) by image processing of clouds ; First, we have developed a basic method to judge weather conditions, that is "fine" or "cloudy, " in a few minutes by means of detection of clouds motion in the sky that mostly affects the PV power with machine vision. Next, a method to estimate solar irradiation over a few minutes has been considered. The method is based on analysis of the ratio of clouds that is going to cover the sun. Estimation of solar irradiation over a longer time, a few hours, has been investigated by using an all-sky camera, too. Furthermore, we have studied a basic method to discriminate between "thick" and "thin" clouds to estimate transmittance of the sunlight.2.Estimation of PV power (solar irradiance) considering the characteristics of solar irradiance ; We have devised a method to estimate daily solar irradiation by the estimation of the atmospheric transmittance from the theoretical equation of solar irradiance and observed solar irradiance. The experiment confirmed that the method precisely estimated the daily solar irradiation on more than half days in 2000.3.Control of the PV-diesel hybrid generation system ; A basic method to control the PV-diesel hybrid generation system using the short-time and long-time estimation of PV power mentioned above has been proposed.Future works are applied studies to combine above basic studies as a system.