Research on Development of Phtovoltaic Generating System without Using the Phase Information of Power Network

不利用电网相位信息的光伏发电系统开发研究

基本信息

批准号：
06650329
负责人：
YAMADA Eiji
金额：
$ 1.34万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

Inverters which are connected to electrical power network operate according to informations of it like as voltages, phases and so on. Photovoltaic power system needs same informations when it is interconnecte d to electrical power network. If exact informations can not be received, large current may flow and transmission power loss may increase. But it is very difficult to detect exact informations because of inductances of electrical power network, distortion of voltage waveform and phase delay due to electrical machines connected to it. These unexpected informations sometimes make the total system unstable.Therefore, using inpedances of the photovoltaic system and the power electrical network, and output current from photovoltaic system, we estimated the power source by minimal order observer. Then we developed novel photovoltaic system. From simulation results of noval system, we recognized that phase of electrical power network could be estimated rapidly even if phases were differe … More nt from detected values and estimated one. Also if source phases change like step function, novel system can follow it. We concluded that novel system could operate stable in case where impedances of transmission line were long as photovoltaic system was apert from electrical power network and distortion of power waveform as large capacity converters exist near it.Until now maximum power following control of photovoltaic generator has been attended by purturbating small value of photovoltaic voltage, and comparating its value to before and after ones. Because system is operated by purturvation of voltage all times, generating power pulsates. Besides, this method has defect that response is slow when illuminance changes widely, though maximum power point can be found.In this paper we have developed novel method that maximum power can be gotten using three points of it ; actuating point, before ones and after. This metho d is one that power characteristic is approximated by second order function and maximum power point can be gotten by only one calculation. So pulsating number of terminal voltage can be decreased.From the results of simulatior which are composed of above mentioned method and source voltage phase estimation one by minimal order observer, it became evident that novel system can follow to maximum power point rapidly and has small pulsation in comparison with normal system. Less

与电力网络连接的逆变器按照其信息（例如电压，相等）操作的逆变器。当光伏电源系统与电力网络互连时需要相同的信息。如果无法收到确切的信息，大电流可能会流动，传输功率损失可能会增加。但是，由于电力网络的电感，电压波形的失真和由于连接到它的电机而引起的相位延迟，因此很难检测到确切的信息。这些意外信息有时会使总系统不稳定。因此，使用光伏系统和功率电网的焊刻，以及来自光伏系统的输出电流，我们通过最小阶观察器估算了电源。然后，我们开发了新型的光伏系统。从新型系统的仿真结果中，我们认识到，即使相位相差，也可以迅速估计电力网络的阶段……与被检测到的值相比和估计值更高。同样，如果源阶段像步骤功能一样变化，那么新型系统可以遵循它。我们得出的结论是，如果传输线的阻抗持续很长时间，则新型系统可以保持稳定，因为光伏系统是电力网络的平均水平，并且功率波形的变形，因为它附近存在大容量转换器。因为系统始终是通过电压的液化来操作的，从而产生功率脉冲。此外，这种方法的缺陷是，当照明变化广泛时，响应很慢，尽管可以找到最大功率。动理点，在一个之前和之后。特征通过二阶函数近似，并且只能通过一个计算获得最大功率点。因此，可以提高脉动端子电压数量。从模拟器的结果中，该结果由上述方法和源电压相估计1通过最小观察者组成，这证明了新系统可以快速遵循最大功率点，并且与正常系统相比具有较小的脉动。较少的