An auxiliary processing device for busbar faults

Abstract

The present invention discloses an auxiliary processing device for busbar faults. An incoming line switch and several outgoing lines are provided on the busbar. A thyristor is respectively connected to each phase line at the lower port of the incoming line switch, and the other ends of the thyristors are connected in parallel with each other. When an interphase short circuit occurs on the busbar, the fault detection device controls all the thyristors to conduct or controls the thyristors directly connected to the faulty phase line to conduct, so as to divert the current at the interphase short circuit fault point. This device can divert the current at the interphase short circuit fault point before the incoming line switch trips to cut off the fault, thereby effectively reducing or eliminating the large amount of heat accumulation caused by arc discharge at the fault point and avoiding the occurrence of explosion accidents.

Description

Technical Field

[0001] The present invention relates to a device, in particular to an auxiliary processing device for busbar faults. Background Art

[0002] In power distribution, generally, a 10 kV incoming line is introduced into an incoming line switch cabinet and connected to the busbar copper bars inside the incoming line switch cabinet. An incoming line switch is arranged inside the incoming line switch cabinet, and then outgoing lines are led out from the busbar copper bars through different outgoing line switch cabinets, and outgoing line switches are arranged inside the outgoing line switch cabinets. If a phase-to-phase short circuit occurs in the busbar copper bars inside the switch cabinet due to an accidental event, a large current discharge will occur along with arc light, and the accumulated high heat may cause an explosion inside the switch cabinet, resulting in significant losses. Although the phase-to-phase short circuit will be detected by a detection device and cause the incoming line switch to trip, the mechanical tripping of the incoming line switch takes time, and an explosion accident may still occur during this time. Currently, there is no particularly effective treatment method for the explosion caused by arc discharge before the incoming line switch trips. Summary of the Invention

[0003] The object of the present invention is to provide an auxiliary processing device for busbar faults, which can divert the current at the phase-to-phase short circuit fault point before the incoming line switch trips to cut off the fault, thereby effectively weakening or eliminating the large amount of heat accumulation caused by arc discharge at the fault point and avoiding the occurrence of explosion accidents.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An auxiliary processing device for busbar faults, wherein an incoming line switch and several outgoing lines are arranged on the busbar. Thyristors are respectively connected to each phase line at the lower port of the incoming line switch, and the other ends of the thyristors are connected in parallel with each other. When a phase-to-phase short circuit occurs on the busbar, all the thyristors are controlled to conduct or the thyristors directly connected to the faulty phase line are controlled to conduct to divert the current at the phase-to-phase short circuit fault point.

[0006] Preferably, a busbar fault is detected by a fault detection device and the thyristors are controlled to act. The fault detection device is an arc detection device or a differential detection device. The arc detection device judges the occurrence of a phase-to-phase short circuit fault by detecting the arc light at the phase-to-phase short circuit fault point and controls all the thyristors to conduct. The differential detection device judges the occurrence of a phase-to-phase short circuit fault by the non-conservation of the incoming line current of each phase of the busbar and the corresponding phase current of each outgoing line and determines the faulty phase, and then controls the thyristors directly connected to the faulty phase line to conduct to divert the current at the phase-to-phase short circuit fault point.

[0007] Preferably, a busbar fault is detected by a fault detection device and the thyristor is controlled to act. The fault detection device includes an inlet current detection unit arranged on each phase inlet line of the busbar and an outlet current detection unit corresponding to the same phase on the outlet line. The current quantity of the inlet current detection unit is converted into an inlet pulse through a voltage-frequency conversion circuit and transmitted to a comparison unit. The current quantity of the outlet current detection unit is converted into an outlet pulse through a voltage-frequency conversion circuit and transmitted to the comparison unit. The comparison unit calculates the difference between the number of inlet pulses and the number of outlet pulses, and determines that the phase line is a fault phase after the difference exceeds a preset value, and simultaneously issues a signal to turn on the thyristor directly connected to the phase line.

[0008] Preferably, both the inlet current detection unit and the outlet current detection unit include a primary current transformer and a secondary current transformer. A weak current signal is obtained from the secondary current transformer, elevated by a reference voltage elevation circuit, and then sent into the voltage-frequency conversion circuit. The comparison unit includes a counter and an adder / subtractor. The counter calculates the number of pulses, and the adder / subtractor calculates the difference from the number of pulses.

[0009] Preferably, the output of the comparison unit is cleared every fixed period.

[0010] Preferably, N comparison units are set to calculate the differences between the respective inlet pulse numbers and outlet pulse numbers in parallel, and the outputs of each comparison unit are cleared every fixed period T, and the start times of clearing for different comparison units are separated by T / N in sequence. When the calculation result of at least one comparison unit exceeds the threshold, a signal is issued to control the thyristor to turn on, where N is a positive integer greater than 1.

[0011] Preferably, the inlet current detection unit is installed at the upper port of the inlet switch.

[0012] Preferably, the period T is set to 3 - 5 milliseconds, and N is set to 3 - 5.

[0013] Preferably, the thyristor is installed in the inlet switch cabinet.

[0014] Preferably, the thyristors are connected in series with resistors and then in parallel.

[0015] In the present invention, after an interphase short - circuit fault occurs in the busbar, the thyristors connected in parallel with the busbar are immediately turned on, and a loop parallel to the fault point is formed through the thyristors and current is conducted, so that the current at the interphase short - circuit fault point can be diverted, effectively reducing the heat release at the fault point and avoiding the occurrence of explosion. If the fault detection device can specifically detect the faulty phase, the thyristors directly connected to the faulty phase can be controlled to turn on, so that the current at the fault point can be diverted more effectively. By using a voltage - frequency conversion circuit to convert the current quantity into pulses and calculating the difference in the number of pulses, the interphase short - circuit fault can be detected faster and the faulty phase can be distinguished, thus making a quick judgment. The present invention utilizes the characteristics of fast response of thyristors and differential methods, and can effectively divert the current at the fault point before the incoming line switch trips, thus effectively avoiding the occurrence of explosion accidents caused by short - circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be further described below with reference to the drawings.

[0018] As Figure 1 shown, the auxiliary processing device for busbar faults is installed on busbar 1. An incoming line switch 2 and several outgoing lines 3 are provided on busbar 1. A thyristor 4 is connected to each of the three - phase lines at the lower port of the incoming line switch 2. The other ends of the three thyristors 4 are connected in parallel. When an interphase short - circuit occurs on busbar 1, it will be detected by the fault detection device, and the fault detection device will control all the thyristors 4 to turn on, thus forming a loop parallel to the fault point and diverting the current at the fault point, reducing the release of heat at the fault point. Or more preferably, if the fault detection device can detect the faulty phase, the thyristor 4 directly connected to the faulty phase line is controlled to turn on to divert the current at the interphase short - circuit fault point. At this time, the thyristors of the non - faulty phases do not turn on, so the manufactured parallel loop is more targeted and the current - shunting effect is better.

[0019] In one embodiment, the fault detection device is an arc - light detection device. The arc - light detection device detects through arc light and cannot distinguish between the faulty phase and the non - faulty phase, so after detecting the arc light, it controls all the thyristors 4 to turn on. In another embodiment, the fault detection device is 3 sets of single - phase differential devices. The differential detection device judges the occurrence of an interphase short - circuit fault by the non - conservation of the incoming line current of busbar 1 and the currents of each outgoing line and can determine the faulty phase, and then controls the thyristor 4 directly connected to the faulty phase line to turn on to divert the current at the interphase short - circuit fault point. At this time, the current - shunting effect is more obvious. Preferably, each of the thyristors 4 is connected in series with a resistor and then in parallel.

[0020] In a preferred embodiment, the fault detection device includes an inlet current detection unit 5 disposed at the inlet end of the busbar 1 at the upper port of the incoming line switch 2 and an outlet current detection unit 6 on the outgoing line 3. The current amount of the inlet current detection unit 5 is converted into an inlet pulse by a voltage-frequency conversion circuit (VFC) and transmitted to a comparison unit 7. The current amount of the outlet current detection unit 6 is converted into an outlet pulse by a voltage-frequency conversion circuit (VFC) and transmitted to the comparison unit 7. The comparison unit 7 calculates the difference between the number of inlet pulses and the number of outlet pulses, and determines that the phase line is a faulty phase after the difference exceeds a preset value. At the same time, a signal is sent to turn on the thyristor directly connected to the phase line, and a signal is sent to trip the incoming line switch 2.

[0021] Both the inlet current detection unit 5 and the outlet current detection unit 6 include a primary current transformer and a secondary current transformer. A weak current signal is obtained from the secondary current transformer, elevated by a reference voltage elevation circuit, and then sent to the voltage-frequency conversion circuit.

[0022] The comparison unit includes a counter and an adder / subtractor. The counter calculates the number of pulses, and the adder / subtractor calculates the difference from the number of pulses.

[0023] The output of the comparison unit is cleared every fixed period to avoid the accumulation of errors exceeding the preset value. In one embodiment, 5 comparison units are provided to calculate the differences between the respective inlet pulse numbers and outlet pulse numbers in parallel, and the output of each comparison unit is cleared every fixed period T (such as 5 milliseconds), and the start clearing times of different comparison units are separated by T / N = 1 millisecond in sequence (N is the number of comparison units, here N = 5). In this way, the busbar fault can be exported in 1 millisecond. When the calculation result of at least one comparison unit exceeds the threshold, a signal is sent to control the thyristor to turn on. N is a positive integer greater than 1, preferably 3, 4 or 5, etc. For further detailed implementation content, reference can be made to the utility model patent CN211183401 U.

[0024] The above embodiments are only several explanations of the concept and implementation of the present invention, and do not limit it. Under the concept of the present invention, technical solutions without substantial transformation are still within the protection scope.

Claims

1. An auxiliary processing device for busbar faults, where an incoming line switch and several outgoing lines are provided on the busbar, characterized in that, a thyristor is connected to each phase wire at the lower port of the incoming line switch, and the other ends of the thyristors are connected in parallel with each other. When an interphase short circuit occurs on the busbar, all the thyristors are controlled to conduct or the thyristor directly connected to the faulty phase wire is controlled to conduct to divert the current at the interphase short circuit fault point.

2. The auxiliary processing device for busbar faults according to claim 1, characterized in that, a fault detection device is used to detect busbar faults and control the operation of the thyristors. The fault detection device is an arc light detection device or a differential detection device. The arc light detection device determines the occurrence of an interphase short circuit fault by detecting the arc light at the interphase short circuit fault point and controls all the thyristors to conduct. The differential detection device determines the occurrence of an interphase short circuit fault by the non-conservation of the incoming current of each phase of the busbar and the corresponding phase current of each outgoing line and determines the faulty phase, and then controls the thyristor directly connected to the faulty phase wire to conduct to divert the current at the interphase short circuit fault point.

3. The auxiliary processing device for busbar faults according to claim 1, characterized in that, a fault detection device is used to detect busbar faults and control the operation of the thyristors. The fault detection device includes an inlet current detection unit provided on each phase incoming line of the busbar and an outlet current detection unit corresponding to the same phase on the outgoing line. The current amount of the inlet current detection unit is converted into an inlet pulse through a voltage-frequency conversion circuit and transmitted to a comparison unit. The current amount of the outlet current detection unit is converted into an outlet pulse through a voltage-frequency conversion circuit and transmitted to the comparison unit. The comparison unit calculates the difference between the number of inlet pulses and the number of outlet pulses and determines that the phase wire is a faulty phase after the difference exceeds a preset value, and at the same time sends a signal to make the thyristor directly connected to the phase wire conduct.

4. The auxiliary processing device for busbar faults according to claim 3, characterized in that, both the inlet current detection unit and the outlet current detection unit include a primary current transformer and a secondary current transformer. A weak electrical signal is obtained from the secondary current transformer and then raised by a reference voltage elevation circuit and then sent into the voltage-frequency conversion circuit. The comparison unit includes a counter and an adder / subtractor. The counter calculates the number of pulses, and the adder / subtractor calculates the difference from the number of pulses.

5. The auxiliary processing device for busbar faults according to claim 4, characterized in that, the output of the comparison unit is cleared every fixed period.

6. The auxiliary processing device for busbar faults according to claim 5, characterized in that, N comparison units are set to calculate the differences between the respective inlet pulse numbers and outlet pulse numbers in parallel, and the outputs of the respective comparison units are cleared every fixed period T, and the start clearing times of different comparison units are separated by T / N in sequence. When the calculation result of at least one comparison unit exceeds the threshold, a signal is sent to control the thyristor to conduct, where N is a positive integer greater than 1.

7. The auxiliary processing device for busbar faults according to claim 3, characterized in that, The inlet current detection unit is installed at the upper port of the incoming line switch.

8. The auxiliary processing device for busbar faults according to claim 6, characterized in that the period T is set to 3 - 5 milliseconds, and the N is set to 3 - 5.

9. The auxiliary processing device for busbar faults according to claim 1, characterized in that the thyristor is installed in the incoming line cabinet.

10. The auxiliary processing device for busbar faults according to claim 1, characterized in that each of the thyristors is connected in series with a resistor and then connected in parallel.

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