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US4471419A Expired / Lapsed US ⏱️ 0.0 years remaining

Circuitry and method of operation for an intermediate-like converter

Assignee: Siemens AG
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Filing: 1982-09-30
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Granted: 1984-09-11
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Expires: 2002-09-30
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Abstract

Abstract Circuitry for, and method of operating, an intermediate-link converter of the type wherein two controlled antiparallel-connected converters are connected via an intermediate link having an impressed voltage to an inverter having a plurality of addressable switches in a three-phase bridge circuit. The polarity of the intermediate-link current is interrogated 30° after every change of the addressing combination of the switches of the inverter. If the interrogated polarity of the intermediate-link voltage is larger than a desired value by a predetermined amount, the converter which is arranged in the feeding-in direction is switched off and the other converter, which is arranged in the feedback direction is switched on. In this manner, a load connected to the inverter can feedback energy into a supply network via the intermediate link and a converter operating as an inverter.

Inventors

  • 👤 Hans-Peter Schneider
  • 👤 Hans-Hermann Zander

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 18:38
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/527

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 177 words
A method for operating an intermediate-link frequency converter of the type wherein electrical energy flows in either of two directions, the intermediate-link frequency converter further being of the type having two controlled antiparallel-connected converters which conduct in feeding in and feedback directions, respectively, and which are connected via an intermediate link to an inverter in a three-phase bridge circuit, the inverter having a plurality of addressable switches, the method comprising the steps of: impressing a voltage across the intermediate link; interrogating the polarity of the intermediate-link current 30° after each change of the addressing combination of the switches of the inverter; comparing the intermediate-link voltage against a reference value; switching on the converter of the intermediate-link converter which is arranged in the feedback direction as long as the interrogated polarity of the intermediate-link current is negative and the intermediate-link voltage is larger by a fixed amount than said reference value; and switching on the converter of the intermediate-link converter which is arranged in the feeding in direction when the converter arranged in the feedback direction is switched-off.
Claim 2
Independent Claim 177 words
A method for operating an intermediate-link frequency converter of the type wherein electrical energy flows in either of two directions, the intermediate-link frequency converter further being of the type having two controlled antiparallel-connected converters which conduct in feeding in and feedback directions, respectively, and which are connected via an intermediate link to an inverter in a three-phase bridge circuit, the inverter having a plurality of addressable switches, the method comprising the steps of: impressing a voltage across the intermediate link; interrogating the polarity of the intermediate-link current 30° after each change of the addressing combination of the switches of the inverter; comparing the intermediate-link voltage against a reference value; switching on the converter of the intermediate-link converter which is arranged in the feedback direction as long as the interrogated polarity of the intermediate-link current is negative and the intermediate-link voltage is larger by a fixed amount than said reference value; and switching on the converter of the intermediate-link converter which is arranged in the feeding in direction when the converter arranged in the feedback direction is switched-off.
Claim 3
Dependent Claim 112 words
A circuit arrangement for operating an intermediate-link frequency converter of the type having an inverter with switches which are addressable in a plurality of combinations to produce output currents at respective outputs, the circuit arrangement comprising: circuit means having an output for producing a polarity signal; electronic measurement value switch means for receiving an intermediate-link current measurement value signal; smoothing stage means for coupling said electronic measurement value switch means to said circuit means; and control means for controlling the conductive state of said electronic measurement value switch means, said electronic measurement value switch means being controlled to a conductive state 30° after each change of an addressing combination of the inverter.
Claim 4
Dependent Claim 112 words
A circuit arrangement for operating an intermediate-link frequency converter of the type having an inverter with switches which are addressable in a plurality of combinations to produce output currents at respective outputs, the circuit arrangement comprising: circuit means having an output for producing a polarity signal; electronic measurement value switch means for receiving an intermediate-link current measurement value signal; smoothing stage means for coupling said electronic measurement value switch means to said circuit means; and control means for controlling the conductive state of said electronic measurement value switch means, said electronic measurement value switch means being controlled to a conductive state 30° after each change of an addressing combination of the inverter.
Claim 5
Dependent Claim 87 words
The circuit arrangement of claim 2 wherein there is further provided multiplexer means, said multiplexer means having a first group of input terminals for receiving respective ones of the output currents of the inverter, and a second group of input terminals for receiving respective signals corresponding to inverted output currents of the inverter, said first and second group of inputs each having at least one switch associated therewith, said switches having second terminals thereof connected to a common output, said switches being controlled by said control means.
Claim 6
Dependent Claim 41 words
The circuit arrangement of claim 2 or 3 wherein there is further provided comparator stage means for producing at an output thereof a signal corresponding to a voltage increase at the intermediate link, when said voltage increase exceeds a predetermined value.
Claim 7
Dependent Claim 42 words
The circuit arrangement of claim 4 wherein there is further provided AND gate means having first and second inputs for receiving said polarity signal and said voltage increase signal, respectively, and an output for producing a signal for selectably actuating the inverters.
Claim 8
Dependent Claim 59 words
The circuit arrangement of claim 2 wherein said circuit means comprises inverting operational amplifier means having an input coupled to said smoothing stage means and an output and limit indicator means coupled to said output of said inverting operational amplifier means for producing an output signal when the input of said inverting operational amplifier means exceeds a predetermined value.

References Cited (Backward Citations)

US4158163A Cited
US4328454A Cited
US4270078A Cited
US4274042A Cited
US4366427A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-09-11 1988-03-12 1988-09-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-09-11 1992-03-12 1992-09-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-09-11 1996-03-12 1996-09-11 $7700.00 Window Closed / Lapsed

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