RESEARCH ON SERIES ACTIVE CAPACITANCE TO POWER SYSTEMS

(1)首席研究员A.Nabae使用极坐标提出了瞬时有功-无功电流和功率的新定义。基于新的定义，研究小组开发了一种新的三相电力系统串联有源电容，它能够补偿由系统阻抗引起的谐波电压降和基波分量的相角延迟。从理论上分析了其动态特性，并通过计算机仿真得到了满意的结果。(2)为了建立最佳的控制算法，需要对包含旋转坐标变换的控制系统进行分析。然后，提出了一种适用于2输入2输出系统的复传递函数，并证明了复传递函数分析法在分析控制系统时的有效性。(3)电源频率总是在（]SY. ±[）0.1Hz，其检测方法是需要解决的重要问题之一。课题组建立了一种新的基波检测方法，该方法利用旋转坐标变换，可以瞬时检测基波频率，作为本课题的研究成果，串联有源电容将有助于解决电力系统稳定性问题和2个并联输电系统的潮流分担问题。

(1) The head investigator A.Nabae proposed a new definition of the Instantaneous Active-reactive Currents and Powers using polar coordinate. Based on the new definition, the research team has developed a new series active capacitance for three-phase power systems, which is able to compensate both harmonics voltage drop and phase angle delay of fundamental component caused by the system's impedance. The dynamic behavior was analyzed theoretically and satisfactory results have been obtained from computer simulations.(2) In order to establish a best control algorithm, it is required to analyze a control system including rotating coordinate transformation. Then, a new complex transfer function applicable to 2-input and 2-output system was introduced and it was shown that the complex transfer function analysis was effective in analyzing the control system.(3) Power source frequency fluctuates always within a range of (]SY.+-[)0.1Hz, and its detection method was one of the important problems to be solved. The project team has established a new detection method of the fundamental wave, in which rotating coordinate transformation is used and the fundamental frequency can be instantaneously detected.As the results of this research project, the series active capacitance will contribute to solve power system stability problem and power flow sharing problem of 2 parallel transmission systems.