Dynamic stability of industrial electrical networks

Stable state

Given that electrical energy is very difficult to store, a permanent balance between production and consumption is vital. Generators, loads and the electrical networks which connect them have mechanical and/or electrical inertias which complicate the maintaining of a balance guararanteeing relatively constant frequency and voltage. When confronted with a power variation, the electrical system normally resumes a stable state after a few oscillations.

However in certain cases the oscillating state can diverge, and studies are then required to avoid this phenomenon and guarantee the stability of the electrical network. These studies are of particular importance in the case of industrial networks which contain one or more generator sets and motors.

The purpose of this Cahier Technique is to understand why instability can appear and to define the main causes and effects of such instability. It explains the precautions to be taken and, using a concrete example, describes how a typical study is conducted.

Electrical networks

Since electrical energy is produced at the same time as it is consumed, production must constantly adapt to consumption. As a result, energy production, transmission and consumption form a complex system known as the electrical network stability of which is vital. An electrical network can vary considerably in power (according to the country where it is installed).

AUTHOR: Schneider Electric experts | Benoît de METZ-NOBLAT, Gérard JEANJEAN