SIMOVERT Master Drives Einspeise-Einheit Bauform E Common ...

02.96 Description1 Description1.1 ApplicabilityThe common rectifier in the SIMOVERT Master Drives series is a power electronics device. From the threephasemains, it generates a dc network and is used as a dc supply unit for one or several units in theSIMOVERT Master Drives inverter series with a dc link.A three-phase mains is connected to the input. One or more inverters and a brake chopper can be connected tothe DC output. The total of the rated currents of the installed inverters may then exceed the rated current of thecommon rectifier. It must however be ensured in the course of system planning that at no moment in time is thetotal of DC load currents greater than the rated DC current of the common rectifier. Feedback to the mains is notpossible.Refer to the technical data in Chapter 14 for details of voltage and current ranges.1.2 Principle of operationThe common rectifier consists of a 6-pulse thyristor bridge for controlled rectification of the three-phase mains.The trigger equipment is independent of the rotary field and is frequency-compensated from 46 to 64 Hz. Afterthe electronic power supply and the mains voltage have been applied, the dc link is precharged by shifting of thephase control firing angle within one second (adjustable to two seconds).The maximum DC link capacitance of a group drive must not exceed three times the capacitance of a singleinverter whose DC link rated current corresponds to the rated current of the incoming unit. Units for operationwith higher DC link capacitance on request.If the DC link voltage drops below a given proportion of the average mains voltage as the result of mains powerfailure or a drop in the mains voltage, the pulses are blocked immediately and precharging takes place again assoon as the mains returns. This prevents excess currents as the result of charging of the dc link capacitors attoo fast a rate when the mains voltage returns.Tapping of load current is not possible during precharging.An earth fault of a connected converter is checked before precharging to protect its frewheeling diodes againstexcess current.The mains voltage, phase failure, excess temperature of the power section, earth faults and the electronic powersupply are monitored. Monitoring triggers deactivation and a fault signal in the event of any hazard. The currentis not monitored.Fault signals are acknowledged by deactivating the mains voltage or the electronic power supply.The power for the electronics is supplied externally via a 24 V DC input.Siemens AG 6SE7087-6AE85-0AA0 ENGLISH 1-1Common Rectifier Operating instructions