STABILIZATION EFFECT OF MULTI-MACHINE POWER SYSTEM BY USING ADJUSTA BLE SPEED GENERATOR

This paper describes a stabilization effect after installating an adjustable speed generator (ASG) in a multi machine power system. A personal computer based ASG module has been de veloped for the simulations in parallel with the analog power system simulator i n the Research Laboratory of the Kyushu Electric Power Co. The three phase ins t antaneous value based ASG model has been developed in the Matlab/Simulink envir onment for its detailed and real time simulations, which have been performed on a digital signal processor (DSP) board with AD and DA conversion interfaces inst alled in a personal computer (PC). Simulational results indicate the hig hly improved overall stability of the multi machine power system after installa ting the ASG.

DT-930F数字万用表测频率档量程的扩展

DT—930F数字万用表以其精度高,价格适中而占有一定的市场,笔者在使用过程中,发现其对检修中经常碰到的20kHz以上的频率无法测量。通过对电路进行分析,试着将其量程扩展为100Hz～200kHz,经过与标准频率计比较,完全达到原设计精度。 1.测量原理为了说明方便,现将原测频部分电路绘制如图1。该图中ICM7555各点的工作波形如图2。从图1中可知,输入频率信号fin经过R1、D1。