Electrical power supply method involves parallel mode with isolated network coupled to public network via protective device that is opened if public network fails to select isolated mode

摘要

The method involves using a parallel mode in which the isolated network is coupled to the public network via a protective device. If the public network fails the coupling protective device is opened to change over to an isolated mode. When the public network is restored a synchronization process takes place and the protective device is closed. The method involves using an isolated network (10) with a three-phase machine (22) for coupling to or coupled to an internal combustion engine (20), a direct current intermediate circuit with storage connected to the network and three-phase machine via a frequency converter (28) and a monitoring and control device. In parallel mode the isolated network is coupled to the public network via a protective device (18). If the public network fails the coupling protective device is opened to change over to isolated mode. When the public network is restored a synchronization process takes place and the protective device is closed. Independent claims are also included for the following: a electrical power supply system.