Speed control system for e.g. electrical hoisting motor, has converter connected to polyphase electrical network and arranged for returning, towards network, fraction of energy susceptible to be restored by electric motor during operation

摘要

The system has a converter (31) connected to a polyphase electrical network and to a DC bus, a power stage (15), a power stage control unit (18), and a filtering stage (32) connected to the bus, where stage includes a capacitor. The converter is reversible and arranged for returning, towards the network, a fraction of energy susceptible to be restored by an electric motor (16) during operation.