Security Indexes for Power System Security Assessment

摘要

The growth and loading of todays power system needs more elaborated tools to monitor the system security in order to find countermeasures in case of system unsecurity and instability. Studying system security refers to analysis of system voltage, transient and small signal stability. The small signal stability problem is usually the one of poor damping of system oscillations. Secure operation of power systems is strongly related to damping of system oscillations; if damping is insufficient the system can undergo stability problems. The paper will combine an index for small system security with a set of indices for the overall system behaviour ranking small system behaviour, transient stability, voltage behaviour and system performance using a fuzzy logic to monitor the system state. In this paper an index for studying system loading of each node is introduced, too. The index allows to define absolute nodal loading. With this index the actual situation, increase in loading or behaviour of the system over the day can be analyzed and monitored in a suitable way.