Synthetic equivalence test circuit for circuit breaker testing

A method for testing high-voltage alternating-current power switches in a synthetic test circuit with a high-current circuit comprising a high-current source connected in series with at least one auxiliary switch and one test switch, and with a high-voltage oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current, comprising the step of:

• connecting the high-voltage oscillating circuit in parallel to the test switch in a time interval before the current zero of the high current with an interruption possibility, which is determined by a half-cycle duration (Th/2) of the oscillating current (ih) less the duration of equivalence (Δtse) of the sole flow of the oscillating current as sequential current in the test switch with a stress exerted upon the switch by the homogeneous current in a direct test circuit,
• wherein the sequential-current flow duration of the equivalence results, at least approximately, from the comparison of the values of common physical stress parameters acting in the test switch during the test, on the one hand, in the synthetic test circuit and, on the other hand, in the direct test circuit, and
• wherein the sequential-current flow duration of equivalence results from the condition that the emissions of arc energy in the test switch in an approximately equally long time interval before the last current zero in the synthetic test circuit and in the direct test circuits are at least approximately equal.

A method for testing high-voltage alternating-current power switches in a synthetic test circuit with a high-current circuit comprising a high-current source connected in series with at least one auxiliary switch and one test switch, and with a high-voltage oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current, comprising the step of:

• connecting the high-voltage oscillating circuit in parallel to the test switch in a time interval before the current zero of the high current with an interruption possibility, which is determined by a half-cycle duration (Th/2) of the oscillating current (ih) less the duration of equivalence (Δtse) of the sole flow of the oscillating current as sequential current in the test switch with a stress exerted upon the switch by the homogeneous current in a direct test circuit,
• wherein the sequential-current flow duration of the equivalence results, at least approximately, from the comparison of the values of common physical stress parameters acting in the test switch during the test, on the one hand, in the synthetic test circuit and, on the other hand, in the direct test circuit, and
• wherein the sequential-current flow duration of equivalence results from the ratio of emitted arc energies described by the function equation
• AER
• =
• W
• 2
• +
• W
• 3
• W
• 1
• in the synthetic test circuit, on the one hand, and in the direct test circuit, on the other hand, when this ratio attains the value of one, and
• wherein a deviation from the duration of equivalence of the sole flow of the oscillating current in the test switch determined thereby is maximum plus/minus 30%.

A method for testing high-voltage alternating-current power switches in a synthetic test circuit with a high-current circuit comprising a high-current source connected in series with at least one auxiliary switch and one test switch, and with a high-voltage oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current, comprising the step of:

• connecting the high-voltage oscillating circuit in parallel to the test switch in a time interval before the current zero of the high current with an interruption possibility, which is determined by a half-cycle duration (Th/2) of the oscillating Current (ih) less the duration of equivalence (Δtse) of the sole flow of the oscillating current as sequential current in the test switch with a stress exerted upon the switch by the homogeneous current in a direct test circuit,
• wherein the sequential-current flow duration of the equivalence results, at least approximately, from the comparison of the values of common physical stress parameters acting in the test switch during the test, on the one hand, in the synthetic test circuit and, on the other hand, in the direct test circuit, and
• wherein the sequential-current flow duration of equivalence related to the half-cycle duration (Th/2) of the oscillating current is given by the equation:
• Δ
• ⁢
• ⁢
• t
• se
• T
• h
• 2
• =
• ϑ
• se
• =
• 1
• -
• [
• (
• κ
• 2
• κ
• 1
• )
• ⁢
• (
• 1
• -
• W
• 3
• W
• 1
• )
• ]
• 0.5
• wherein a deviation from the relative duration of equivalence of the sole flow of the oscillating current in the test switch determined thereby is maximum plus/minus 30%.

A method for testing high-voltage alternating-current power switches in a synthetic test circuit with a high-current circuit comprising a high-current source connected in series with at least one auxiliary switch and one test switch, and with a high-voltage oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current, comprising the step of:

• connecting the high-voltage oscillating circuit in parallel to the test switch in a time interval before the current zero of the high current with an interruption possibility, which is determined by a half-cycle duration (Th/2) of the oscillating current (ih) less the duration of equivalence (Δtse) of the sole flow of the oscillating current as sequential current in the test switch with a stress exerted upon the switch by the homogeneous current in a direct test circuit,
• wherein the sequential-current flow duration of the equivalence results, at least approximately, from the comparison of the values of common physical stress parameters acting in the test switch during the test, on the one hand, in the synthetic test circuit and, on the other hand, in the direct test circuit, and
• wherein the sequential-current flow duration of equivalence related to the half-cycle duration (Th/2) of the oscillating current is given by the equation:
• Δ
• ⁢
• ⁢
• t
• se
• T
• h
• 2
• =
• ϑ
• se
• =
• 1
• -
• [
• (
• κ
• 2
• κ
• 1
• )
• ⁢
• (
• 1
• -
• W
• 3
• W
• 1
• )
• ]
• 0.5
• =
• const
• .
• =
• ϑ
• sc
• wherein the value of the constant is set so that the thus represented function graph approximates to the function graph of equivalence at least in sections, to the maximum of these two function graphs intersecting each other, and a deviation from the relative duration of the sole flow of the oscillating current in the test switch determined thereby is maximum plus/minus 30%.

A synthetic test circuit for high-voltage alternating-current circuit-breakers, comprising:

• a high-current circuit containing a high current source connected in series with at least one auxiliary switch and one test switch, and with a high-current oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current,
• wherein a open current circuit, comprising a voltage-conducting capacitance chargeable with voltage connected in series with at least one current-limiting resistor, is connected parallel to the auxiliary switch, and the current circuit is closed by means of a switching mechanism device before a current zero of the high current with interrupting possibility by the test switch, whereupon a current of relatively smaller amplitude and opposite polarity is superimposed to the high current in the auxiliary switch,
• wherein the superimposed current is interrupted by the same or by another switching mechanism before or at the time of the current zero of the high current, and
• wherein a capacitance conducting voltage and connection in series with at least one inductance is connected in parallel to the auxiliary switch before the last current zero of the high current through a controlled triggerable spark gap, whereupon an oscillating current of relatively smaller amplitude and higher frequency with opposite polarity is superimposed to the high current, and this superimposed current is interrupted by a switch in a current zero before or at the time of the current zero of the high current.

A synthetic test circuit for high-voltage alternating-current circuit-breakers, comprising:

• a high-current circuit containing a high current source connected in series with at least one auxiliary switch and one test switch, and with a high-current oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current,
• wherein a open current circuit, comprising a voltage-conducting capacitance chargeable with voltage connected in series with at least one current-limiting resistor, is connected parallel to the auxiliary switch, and the current circuit is closed by means of a switching mechanism device before a current zero of the high current with interrupting possibility by the test switch, whereupon a current of relatively smaller amplitude and opposite polarity is superimposed to the high current in the auxiliary switch,
• wherein the superimposed current is interrupted by the same or by another switching mechanism before or at the time of the current zero of the high current, and
• wherein the auxiliary switch is triggered in time so that the contacts thereof separate, within the time interval of a partial oscillation of the high current, at which current zero already exists as a possibility to interrupt the circuit by the test switch, shortly before reaching the peak current value, in the peak current value, or shortly after reaching the peak current value.

A synthetic test circuit for high-voltage alternating-current circuit-breakers, comprising:

• a high-current circuit containing a high current source connected in series with at least one auxiliary switch and one test switch, and with a high-current oscillating circuit comprising a high-voltage source to be connected parallel to the test switch before the current zero of the high current, at which already an interruption possibility exists, and conducting an oscillating current,
• wherein a open current circuit, comprising a voltage-conducting capacitance chargeable with voltage connected in series with at least one current-limiting resistor, is connected parallel to the auxiliary switch, and the current circuit is closed by means of a switching mechanism device before a current zero of the high current with interrupting possibility by the test switch, whereupon a current of relatively smaller amplitude and opposite polarity is superimposed to the high current in the auxiliary switch,
• wherein the superimposed current is interrupted by the same or by another switching mechanism before or at the time of the current zero of the high current, and
• wherein a capacitance conducting voltage and connection in series with at least one ohmic resistor is connected in parallel to the auxiliary switch before the last current zero of the high current through a controlled triggerable spark gap, whereupon an aperiodic current of relatively smaller amplitude with opposite polarity is superimposed to the high current, and the superimposed current is interrupted by a switch in a current zero before or a the time of the current zero of the high current.