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AssigneeSiemens Aktiengesellschaft
InventorGunter Schwesig
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For the alternating drive of switches of a pulse frequency converter acting on a common AC-side terminal, the control pulses of the switches must be jointly latched at each alternation. For each switch, the control signal applied for its latching may be regarded as a set value for its switch voltage, whereas the actual switch voltage occurs only if after a storage time this switch actually extinguishes. By integration of the deviance, therefore, a correction signal is formed which is proportional to the storage time of the last fired switch or to the voltage-time area occurring at the output during the latch time. Thereby the distorting influence of voltage-time areas which are caused due to the spread between units of different latch times of different switches can be taken into consideration in the formation of the width-modulated control pulses.
A method for operating a pulse frequency converter, in particular a pulse frequency converter having transistor or gate turn-off thyristor switches, comprising forming, from a control voltage for two frequency converter switches coupling a common AC output terminal of the converter alternatingly to one of two DC input connections to the converter, two pulse width modulated control pulses for the alternating drive of respective ones of said two switches, interlocking the switches jointly briefly between the two pulse width-modulated control pulses during a latch period, generating a voltage-time area by integration during the latch periods from a measured signal corresponding to a switch voltage and controlling the width of the control pulses with a correction quantity derived from the generated voltage-time area as an interference quantity.
Apparatus for operating a pulse frequency converter, in particular a pulse inverter having transistor or gate turn-off thyristor switches comprising:
Dependencies are inferred from the claim text.