Safety function control for an electric machine and method of operating the electric machine
AssigneeBaumueller Nuernberg GmbH
InventorsUWE HENSEL, MAGDI DIMAS-ZEKRI, AXEL HELMERTH
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Abstract
An apparatus and a method actuate a frequency converter of an electric machine having a safety function, in particular a safe-torque-off (STO) function. Wherein, by a preferably clocked converter circuit, an electrically isolated output voltage is generated from an input voltage, from which output voltage a control signal is generated for the frequency converter for the operation thereof in accordance with standards and for triggering the safety function. An actuation signal is generated for a semiconductor switch which is periodically connected to the input voltage, and the output voltage is limited when the output voltage exceeds a switching threshold.
Claims12
A method for actuating a frequency converter of an electric machine having a safety function, which comprises the steps of:
- generating an electrically isolated output voltage for a normal operation of the frequency converter and for triggering the safety function from an input voltage, the output voltage generated by a converter circuit;
- supplying the output voltage to a threshold switch for generating a binary control signal for the frequency converter, the binary control signal activating an operation of the frequency converter when the output voltage exceeds an upper threshold value, the binary control signal triggering the safety function for deactivating the operation of the frequency converter when the output voltage undershoots a lower threshold value;
- generating an actuation signal from the output voltage for a semiconductor switch of the converter circuit, the semiconductor switch being periodically connected to the input voltage;
- and
- limiting the output voltage when the output voltage exceeds a switching threshold.
An apparatus, comprising:
- a converter circuit containing a transformer having, on a primary side, a semiconductor switch for providing an electrically isolated output voltage from an input voltage and, on a secondary side, a rectifier;
- and
- an open-loop and/or closed-loop control device connected downstream of said rectifier, said open-loop and/or closed-loop control device generating a control signal for a frequency converter for triggering a safety function and an actuation signal for said semiconductor switch when the output voltage exceeds a maximum value.
Dependencies are inferred from the claim text.