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，针对船舶光伏-柴油混合动力系统由于光伏功率不均匀而产生的问题，开展了光伏功率估算的基础性研究。研究结果包括：1.通过对云层进行图像处理来估计光伏功率(太阳辐照度)；首先，我们提出了一种通过机器视觉检测天空中主要影响光伏功率的云层运动来判断天气状况的基本方法，即在几分钟内判断天气状况是晴朗还是多云。接下来，我们考虑了一种估算几分钟内太阳辐射的方法。该方法是基于对将要覆盖太阳的云层比率的分析。对更长时间，几个小时的太阳辐射的估计，也已经使用全天相机进行了调查。2.考虑太阳辐照度的特点，估算光伏功率(太阳辐照度)；从太阳辐照度理论方程和观测太阳辐照度方程出发，通过估算大气透过率，提出了一种估算日太阳辐照度的方法。实验验证了该方法能准确估计出2000年半天以上的日太阳辐射量。3.光伏-柴油混合发电系统的控制；提出了一种利用上述光伏功率的短期和长期估计来控制光伏-柴油混合发电系统的基本方法。

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.