Optimal Design Of Grid-oriented Supervisory System For Grid-connected Photovoltaic Power Plant

With the energy crisis coming, all the countries pay high attention to and study on photovoltaic power and related technology. Though photovoltaic power has some characteristics as sunshine is endless, it can achieve a good place balance with the load. because of its own characteristics affected by weather, which are different from other conventional electricity, it made what contain Grid-connected photovoltaic power running security, stability and reliability , and affect brought after it accesses to power grid became the key factor of photovoltaic grid-connected generation .From the point of the grid'view, A bi-direction and multi power and energy exchange exists between photovoltaic power plant and its connected power grid and it follows a complicated scheme for their energy rate settlement, therefore it is necessary to make a suitable and optimal data acquisition and monitoring for the PV's electrical energy output quality and quantity as well as the parameters measurement specified for electric rate settlement. This paper's core is 5W1H of photovoltaic monitoring system, that is :(1) Why, the purpose of surveillance: the main affect to grid from PV plant is electrical energy quality and fair settlement; (2) What, what should be monitored?: some related measuring quantity ;(3) Where, where to monitor?: to gain from photovoltaic power station monitoring system and special added grid point field terminal ;(4) When, when should be monitored and frequency of monitoring? ;(5) Who, which department of Grid Company will monitor? ;(6) How, how to monitor?This paper's main content can be divided into three parts: Based on the energy production process, the common and special property of data acquisition is studied, including communication, selecting one from two integrated grid company information systems as substation/power plant or customer electrical energy data acquisition and supervisory system, in which the integration scheme in PV station side is discussed. As per the energy exchange with different rate between PV station and grid company, in order to prevent the illegal or mistake, it is needed to build a possible electrical energy output model, and make a possible power output according to the remote measurement of solar illumination and its balance with two-ways electrical energy metering; the suitable model is proposed and sensitivity and error analysis is adopted to the steady and measurement parameters of the model, from which the optimal selection of steady parameters as well as measurement scheme is suggested to achieve a economic and effective monitoring system.