DEVELOPMENT OF PV-ECS SYSTEM WITH INTELIGENT FUNCTION

作为进一步利用可再生能源的一种手段，期望开发自主光伏系统，其日发电模式完全独立于可用的太阳辐射模式。为了实现这种环保型光伏发电系统，必须在光伏发电系统中加入某种储能装置，本文采用一种带有电子电路元件的超级电容器作为储能装置，开发了一种具有智能功能的光伏储能系统。本文的主要研究成果如下：（1）采用双向逆变器，新系统的能量利用率和控制能力较以往的PV-ECS系统有了很大的提高。（2）利用Hotell的光束辐射方程和Lie和Jordan的漫射辐射方程，提出了一种可靠、实用的太阳能利用率估算方法。(3).A计算晴天的前一天可用太阳能，以该理论能量为基准值，与各种天气条件下的实际测量值进行比较，确定晴天、阴天和雨天各种天气条件下的能量因子。（4）为了实现负荷均衡功能，我们开发了一种基于天气预报的可利用太阳能的PV-ECS系统日常运行优化算法，并通过各种实验结果证实了其有效性

As a means for further utilization of the renewable energy, the development of autonomous photovoltaic system of which daily generation pattern is totally independent from the available solar radiation pattern is expected. To realize this type of an environment friendly PV system, some kind of energy storage device must be added to PV system, and we use a super capacitor with electronic circuit elements, called ECS (Energy Capacitor System), as a power storage device and developed a grid-connected PV-ECS system with intelligent function in this study. Main feature of the developed PV system is in its ability to realize a load leveling function using a day-ahead weather forecast.The study results are summarized as follows :(1).Using the bi-directional inverter, the new system's energy efficiency and control ability are improved greatly compared with those previously developed PV-ECS system.(2).Using the Hotell's equation for the beam radiation and the Lie and Jordan equation for the diffused radiation, we developed a reliable and practical estimation algorithm for available solar energy at the system site.(3).A day-ahead available solar energy for a sunny day is calculated Setting tins theoretical energy as a base value and comparing with the actually measured value for various weather conditions, energy factors for various weather conditions of fair, cloudy and rain are determined.(4).To realize the load leveling function, we developed an optimization algorithm for the daily PV-ECS system operation using weather forecast based available solar energy and confirmed its usefulness through the various experiment results