The Study Of Automatic Separation And Low-Frequency Separation Device In Power System

When oscillation occurs in interconnected power systems, if there areno effective measures to identify and control, the oscillation will spreadand result in blackout. As an important approach to ensure the safety andstable operation of electric power system, Out-of-step Separation is one ofimportant means to prevent electric network collapse. When the stability ofthe major system is destroyed, the key to this problem is how to prevent theoscillations rationality and quickly, and how to restoration rapidly. It is aneffective measure to split the system at proper spots to ensure thestabilization of each subsystem.Through the analyses to the asynchronous oscillation in power system,by systematic researches on the existing out-of-step criteria of powersystem, it introduces the out-of-step criteria of this device. It makes severalcriteria work reusable, so it fully takes advantage of every criteria, so thatthe defect can be avoided.This device can be applied to small and medium-sized enterpriseswhich has power generating set for itself, and high cost-performance singlechip ATmega16L is used as the core in this device, and it use redundant system which has two CPU to ensure the stabilization of the system, it cancheckout the frequency, voltage and the power flow direction of theinterconnected power systems, and make a comprehensive judgments torealize the control to the out-of-step separation system. It uses the methodof software filtering in the collection of parameter, and has the functions ofauto-disconnection, three grade load reductions; it also has the functions ofblocking protection and secret code protection and so on. It can exclude thefalse action because of the abnormal condition of the system such as shortcircuit and open circuit, so it can ensure the normal operation of the deviceand reduce the loss. When it is designed, the reliability, adaptability,opening and extensibility of this device are full considered to adaptdifferent requirements on the functions and the requirement of powersystem development.