EXPERIMENTAL STUDIES ON STABILITY OF POWER SYSTEMS COMPOSED OF MANY DISPERSED POWER SOURCED USING MICRO-MACHINES

我们进行了两年的实验研究，以实验验证仿真结果，分析包括回路在内的更复杂的电力系统的静态稳定性。取得的成果和下一步要做的工作如下。静态稳定模拟器实验结果：利用超小型交流发电机、飞轮、直流电机和输电线路电感搭建了静态稳定模拟器，组成了纵向电力系统和环路电力系统。测量了3机、4机和5机组成的每个系统的稳态稳定极限。结果表明，无论机器数量多少，环路系统都比纵向系统更稳定。含回路的复杂电力系统的仿真结果：通过特征值计算，对顶形电力系统(两端与相邻电力系统互联的环状电力系统)和梯形电力系统(多个中间点互联的环状电力系统)的稳态稳定性进行了分析。通过改变互联线路的电抗并计算特征值，可以看出这些电力系统具有纵向系统和环路系统的特点。下一步要做的研究：在目前的研究中，假设所有分散的电源都是一个同步发电机。但在实际电力系统中，存在着许多分散的电源，将直流输出功率转换为交流电源，并与交流电力系统互联。这类电力系统的稳定性有待分析。

We have for two years done experimental investigation in order to experimentally verify the results of the simulation on the variation of steady-state stability owing to the looped interconnection of longitudinal power systems at the both ends, and to analyze the steady-state stability of more complex power systems including loops. The obtained results and the works to be done in the future are as follows.1. Results of experiments on steady-state stability simulator : The steady-state stability simulator was constructed from extremely small-sized ac generators, fly-wheels, dc motors and transmission line inductors, and longitudinal power systems and looped power systems were constituted. Steady-state stability limits were measured on each system with 3-machine, 4-machine and 5-machine composition. It was ascertained that the looped systems are more stable than the longitudinal systems regardless of the number of machines.2. Results of simulation on complex power systems including loops : Steady-state stability was analyzed by eigenvalue calculation for a top-shaped power system (a looped power system with the both ends interconnected to neighboring power systems) and a ladder-shaped power system (a looped power system with several intermediate points interconnected each other). It was made clear by changing the reactance of the interconnecting lines and calculating the eigenvalues that these power systems possess the characteristics of longitudinal systems and looped systems.3. Studies to be done in the future : In the present studies, all the dispersed power sources are assumed to be a synchronous generator. But in practical power systems, there exist many dispersed power sources, where the dc output power is converted into ac, and interconnected to ac power system. The stability of such power systems is to be analyzed.