KR940003000B1 - Automatic sectionalizing breaking switch - Google Patents

Abstract

a sectionalizer function unit and a overload cutoff unit. The detector which detects the status of no voltage in the power supply even in the case of the light load by setting limiting current lower than 0.5 [A is disposed between the rectifying circuit and the current suppressing circuit of the sectionalizer function unit.

Description

Automatic failure breaker for track failure section

Figure 1 is a block diagram of a circuit failure section automatic switching device according to the present invention.

2 is a circuit diagram of a voltage-free detector applied to the apparatus of the present invention.

3 is a circuit diagram of another embodiment of the voltage-free detector applied to the apparatus of the present invention.

* Explanation of symbols for main parts of the drawings

1,1 ′: Ground fault and phase current transformer 2,2 ′: Rectifier circuit

3,3 ': open level selection circuit 4,4': cutoff level selection circuit

5: ground fault timing circuit 6: cutoff current detection circuit

7 smoothing circuit 8 timing reset circuit

9: open current detection circuit 10: delay circuit

11 pulse generating circuit 12 firing circuit

13 phase timing circuit 14 interlock circuit

15: current suppression circuit 16: trip energy storage circuit

17: trip coil 18: inrush suppression current circuit

19: level rising circuit 20: inrush current timing circuit

21: reference voltage generation circuit 30: no-voltage detection unit

R₁-R ₈ : resistance C₁: smoothing capacitor

ZD ': Zener Ion VR': Variable element

OP₁: Voltage Amplifier OP₂: Comparator

C ₁₀ , C ₁₁ : condenser

The present invention relates to an automatic open circuit breaker of a line fault section that separates a line fault section in cooperation with a back protection device when a fault current on the load side occurs. Particularly, in order to improve characteristics for performing an inrush current suppression function under light load, The amplification means for amplifying the current value is set to lower the detection current limit value, which is judged as a no-voltage under light load, and thus prevents malfunction due to inrush current suppression when the fault current occurs during light load operation. The present invention relates to an automatic open circuit breaker for a line failure section to improve the reliability of the operation for the no-voltage detection.

In general, an automatic sectionalizing breaking switch (hereinafter referred to as an ASBS) with a sectionizer function and an overload breaking function, which is used as a protection device for a distribution system, is an after-protection device when a fault current on the load side occurs. A distribution line protection device that separates fault sections in cooperation with the company, which is shown in the patent applications Nos. 84-2978 and 84-7379, which are pre-registered by the company.

That is, according to the present invention, through the correction of two independent currents, one side is opened in a voltage-free state after failure detection, and the other functioning as an overload protection device having a TC (Time Current) characteristic, but the voltage-free opening operation has priority. Applied to the device, it can be used as a complete settler and as an overload protection device under the sectioner of the sectioner's operating current, so the TC characteristic of the ASBS itself can be easily used in areas where it is difficult to cooperate with other devices. There is an advantage that is applicable.

However, in case of failure of load side in such a circuit failure section, the set of shaft when the voltage is reduced by the operation of the post-protection device after fault detection through a series of operations such as current sensing, selection, level detection time delay and tripping when a load side fault occurs. In the range of self-blocking capability, the fault section is quickly disconnected and the fault section is quickly disconnected.However, the judgment of the no-voltage on the power supply side is a voltage formed by the current on the secondary side of the current transformer through a circuit called a current suppression circuit. Under constant current value at light load, even though the power supply is not de-energized, the failure section automatic switchgear (ASBS) determines that there is no voltage at which the back-off protection device is open. Because it suppresses the operation for the corrected time, it will not be able to perform normal functions. In addition, the limit value of the sensing journal, which is determined as a no-voltage at light load, is about 3 [A], which has a disadvantage of lowering reliability of operation.

Accordingly, the present invention amplifies the secondary current value (or voltage value) detected by the current detection or voltage detector as a current transformer or capacitor divider in the conventional automatic circuit breaker of the circuit failure section to solve the problems of the prior art. By installing an amplifying circuit, the detection current limit value, which is judged as a no-voltage at light load, is lowered, thereby preventing malfunction of the inrush current suppression function early due to improved operation reliability or fault current at light load operation. It is an object of the present invention to provide an automatic opening and closing device for a track failure section.

Hereinafter, the configuration of the present invention with reference to the accompanying drawings in detail as follows.

As shown in FIG. 1, the apparatus for automatically disconnecting the track failure section of the present invention comprises a voltage-free operation section analyzer function part A and an overload interruption function part B. As shown in FIG.

The voltage-free operation section analyzer function A connects rectifier circuits 2 and 2 ＇to ground fault and phase current transformer 1 and 1 하는 respectively for monitoring the current flowing in the line, and their output stages are The delay circuit 10 is commonly connected to the open fault current detection circuit 9 through the ground fault-free voltage open level selector circuit 3 and 3 kHz, and is connected to the output terminal of the open fault current detection circuit 9, respectively. Is connected to the pulse generating circuit 11 together with the inrush current suppressing circuit 18 connected with the output level rising circuit 19 of the current suppressing circuit 15 connected to the output terminal of the rectifying circuit 2k. The voltage-free detection unit 30 is connected between the rectifier circuit 2 와 and the current suppression circuit 15, and the output stage firing circuit 12 is connected to the output terminal of the rectifier circuit 2 을 via the trip coil 17. It is connected to the trip energy storage circuit 16 is connected, and the reference voltage generating circuit 21 at the output terminal of the rectifier circuit (2 ＇) , It is configured to interconnect the inrush current, the timing circuit 20.

In addition, the overload cut-off function unit B outputs the output of the cut-off level selection circuit 4 and 4 연결 connected to the output terminal of the rectifier circuit 2 and 2 의 of the section analyzer function unit A. (5) is connected to the firing circuit 17 and connected to the interruption fault current detection circuit 6 together with the output of the interruption level selection circuit 4 하여 to provide timing recovery through the smoothing circuit 7. The set circuit 8 is connected to the ground fault timing circuit 5, and the phase timing circuit 13 between the cut-off current detecting circuit 4k and the firing circuit 12 is connected to the timing reset circuit 8; The interlock 14 is interposed between the section array function unit A and the overload interruption function unit B.

In addition, the voltage-free detection unit 30 of the section analyzer function unit A smoothes the rectified voltage output by rectifying the secondary sense current of the phase current transformer 1 ＇as shown in FIG. Through the capacitor (C₁), the distribution resistor (R₂) (R₃) for dividing the smoothed DC voltage, and the zener diode (ZD 시키는) for stabilizing the divided voltage, the limiting voltage (R₄) for limiting the voltage to a certain value, A voltage amplifier (OP₁) for amplifying the input current, a variable element (VR₁) for setting and adjusting the reference value to the driving voltage value of the rear circuit through the feedback resistor (R ₅ ), and a reference level of the comparison value. distribution resistors for providing (R ₇₎ (R ₈₎ and a level of the switching control of the back end circuit compares the reference voltage with the output value and the distributed resistor (R ₇₎ (R ₈₎ of the aeration (OP₁) of the voltage It consists of a detection comparator (OP₂). Reference numerals R₁ and R ₅ in FIG. 2 denote protection resistors and voltage conversion resistors of the power amplifier OP₁.

Referring to the embodiment and the operation and effect of the apparatus of the present invention configured as described above with reference to FIGS. 1 and 2, first, when the current flows in the line as shown in FIG. Iv) detects the current flowing in the track.

Its detected current is converted into direct current through each rectifier circuit (2) (2 ＇), and then the cutoff level selection circuits (4), (4＇) and the Sensitizer function unit (A) of the overload breaking function unit (B). Is applied to the open level selection circuit (3) (3 ms), trip energy storage circuit (16), reference voltage generator circuit (21), and inrush current timing circuit (20). .

At this time, if the direct current supplied through the rectifier circuit (2) (2 ＇) flows into the line above the open fault current level set in the open level select circuit (3) (3＇), (1) (1 ＇) open level select circuit. (3) (3k) drives the open fault current detection circuit 9, while the open fault current detection circuit 9 drives the delay circuit 10.

At the same time, since the direct current rectified through the rectifying circuit 2k is also applied to the no-voltage detecting unit 30, the no-voltage detecting unit 30 drives the current suppressing circuit unit 15, which is described in more detail with reference to FIG. 2. In other words, as shown in FIG. 2, the DC rectified through the rectifying circuit (2 ＇) is smoothed and divided by the smoothing capacitor (C₁) and the distribution resistor (R₂) (R₃), respectively, to obtain the limiting resistance (R₄). When the voltage amplifier OP 반 is input to the non-inverting input terminal (+) of the voltage amplifier OP 증, the voltage amplifier OP₁ converts the limited current input through the limiting resistor R₄ into a voltage and is detected by the phase current transformer (1 ＇). It amplifies the value of the difference current and outputs an amplified voltage capable of driving the rear end circuit (current suppression circuit) through its output stage.

The output reference value required for driving the rear stage circuit is set by adjusting the variable element VR ₁ connected to the inverting input terminal (−) of the output of the voltage amplifier OP₁ fed back through the limiting resistor R5.

As described above, the output of the voltage amplifier OP₁ is set to be larger than the reference voltage of the distribution voltage applied to the inverting input terminal (-) of the level detection comparator OP₂ in the state where current flows in the line as described above. On the contrary, when the output terminal of the line and the rectifying circuit 2k is in a no-voltage state, it becomes smaller than the host non-voltage value of the inverting input terminal (−) of the level detection comparator OP2.

Therefore, when current flows through the line, the output of the voltage amplifier OP₁ is greater than the reference voltage applied to the inverting input terminal (-) of the level detection comparator (OP₂), so that the 'high' level is increased through the level detection comparator (OP₂). It is output and drives the current suppression circuit 15 of FIG.

As described above, when current flows in the line as described above, the current suppression circuit 15 is operated by the voltage-free detection unit 30 and is opened by a current equal to or greater than the open fault current level of the open level selection circuit 3 ＇as described above. The fault current detection circuit 9 is driven to drive the delay circuit 10, but the output of the delay circuit 10 is a driving signal of the voltage-free detection unit 30 ('high': current is flowing in the line). The current suppressing circuit unit 15 is operated to suppress the pulse generation circuit 11 is suppressed.

However, if the line is interrupted by the unchecked after-protection device, the line is in a no-voltage state, and the output of the no-voltage detector 30 is less than the reference voltage value of the level detection comparator OP2 of FIG. Since the output value is small, the 'low' level is applied to the input terminal of the current suppression circuit 15 to turn it off.

Accordingly, since the current suppressing circuit 15 loses its output, the pulse generating circuit 11 normally generates a pulse, which drives the firing circuit 12 and at the same time the trip energy storage circuit ( The output of 16) excites the trip coil 17 and disconnects and disconnects in the fault-voltage-free state.

At this time, since the interlock 14 is driven by the output of the delay circuit 10, the interruption level selection circuit 4 (4k), the interruption current detection circuit 5 and the phase timer circuit ( 13) timing is suppressed.

Therefore, when a current of more than the open current level flows in the line, a pulse is generated by the pulse generating circuit 11, and the failure section is disconnected and disconnected in the no-voltage state through the firing circuit 12 and the trip coil 17.

On the other hand, when the current flows larger than the breaking current and smaller than the open current due to a failure in the line, the breaking failure detection circuit 6 is driven by the breaking level selection circuit 4 (4 ＇), and this output is a smoothing circuit ( In this case, the signal generated by the open level selector circuit 3 (3 ＇) is small in size so that the open current detection circuit 9 cannot be driven, so that the delay circuit 10 and the interlock circuit are not smooth. (14) It also does not work.

Therefore, since the output of the smoothing circuit 7 is not suppressed, the timing reset circuit 8 is reset so that the phase timing circuit 13 or the ground timing circuit 5 is timing according to the phase fault current and the ground fault current. When the timing is completed and the timing is completed, the phase timing circuit 13 or the ground timing circuit 5 generates an output to drive the firing circuit 12 so that the energy is independent of the driving state of the current suppression circuit 15. The output of the storage circuit 16 excites the trip coil 17 to isolate and isolate the fault section.

If the current was higher than the open level before the back protection device removes the fault current to suppress the inrush current generated when the line is repressurized, it is prepared for the inrush current.

That is, when a current above the open level flows, there is an output of the delay circuit 10 through the open level selection circuit 3 (3 ＇) and the open level detection circuit 9, and the inrush current is caused by the output of the delay circuit 10. Since the suppression circuit cannot be set, the level rise circuit cannot be connected, and failure detection is normally performed when the line is re-pressed.

On the other hand, when a current below the open level flows, the output of the open level detection circuit 9 does not occur, so that there is no output of the delay circuit 10. Thus, the inrush current suppression circuit 10 is set and the level rise circuit 19 sets the reference potential. It is connected to (0 potential) to suppress the inrush current until it is reset by the inrush current timing circuit 20 when the line is re-pressurized, the inrush current timing circuit 20 operates when current flows in the line and suppresses the inrush current It operates after the formation time and cuts off the level rise circuit from the reference potential (zero potential) to perform normal fault detection.

In this way, if there is no voltage by the operation of the backup protection device after fault detection through a series of operation of current detection, selection, level detection time delay and trip operation in case of fault occurrence, the shaft is set up and time trip within the self-blocking capability range. Here, if a fault occurs during light load operation that trips within the self-blocking capability range, the inrush current suppression function is performed like the operation when the current below the open level flows. After this elapses, the inrush current timing circuit 20 interrupts the level rise circuit 19 from the reference potential to perform normal fault detection.

Therefore, by lowering the detection current limit value which is determined as the no-voltage during light load operation, the no-voltage detection unit 30 is operated regardless of the load condition, thereby preventing the malfunction due to the inrush current suppression.

3 is another embodiment of the voltage-free detection unit 30 applied to the apparatus of the present invention, by connecting the capacitor voltage divider circuits C ₁₀ and C ₁₁ to the input terminal of the rectifying circuit 2 검출 to detect the voltage flowing in the line. You can also do it.

As described above, the present invention provides a current transformer secondary current to improve the characteristics of the inrush current suppression function in the case of a line failure section automatic switchgear which separates a line failure section in cooperation with a back protection device when a fault current on the load side occurs. A voltage-free detection unit that amplifies the value of 어 reduces the detection current limit value, which is judged as a voltage-free operation under light load, to 0.5A or less, and detects it by preventing inrush current when a fault current occurs during light load operation. Not only can it be prevented, it is also possible to further improve the reliability of operation for voltage-free detection regardless of load conditions.

Claims (3)

Ground fault and phase current transformer circuit (1) (1 ＇), rectifier circuit (2) (2＇), ground fault and phase open level selection circuit (3) (3 ＇), open current detection circuit (9), delay circuit (10) ), The pulse generating circuit 11, the firing circuit 12, the trip coil 17, the trip energy storage circuit 16, the reference voltage generator circuit 21 is coupled to the current suppression circuit 15, A section analyzer function unit (A) having an inrush current suppression circuit (1 *), a level rise circuit (19), and an inrush current timing circuit (20); Cutoff level selection circuit 4 (4 kW), ground fault timing circuit 5, cutoff current detection circuit 6, smoothing circuit 7, timing reset circuit 8, phase timing circuit 13 and interlock In a circuit failure section automatic switchgear comprising an overload cut-off function section (B) having a circuit (14), 0.5 [deg.] Between the rectifier circuit (2k) and the current suppression circuit (15) of the section analyzer function (A). A] The circuit breaker automatic opening and shutting device characterized in that it comprises a non-voltage detection unit 30 for detecting the power supply side voltage-free state even at light load operation by setting the following low detection current limit value. The rectifier voltage according to claim 1, wherein the non-voltage detector 30, which detects a no-voltage state at the power supply side even at light load operation, rectifies and outputs the secondary-side sense current of the phase current transformer 1 kV by the low sensing current limit value. Limiting voltage (R₄) to a certain value through a smoothing capacitor (C₁) to smooth the voltage, a divider resistor (R₂) (R₃) to divide the smoothed DC voltage, and a zener diode (ZD₁) to stabilize the divided voltage. ), A voltage amplifier (OP₁) for amplifying the current input through it, and a variable element (VR₁) for setting and adjusting a reference value with a driving voltage value of a rear circuit through a feedback resistor (R ₅ ). By comparing the distribution resistors R ₇ and R ₈ to provide the reference level of the value, the output value of the voltage amplifier OP₁ and the reference voltage values through the distribution constants R ₇ and R ₈ , It is composed of level detection comparator (OP₂) for switching control of back-end circuit. Line fault section automatic opening device for blocking a. According to claim 1 or 2, wherein the phase current transformer (1 ') as a means for detecting the current flowing in the line divided cone densyeo line fault section automatic opening, characterized by possible even replaced by (C _10, C ₁₁₎ Blocking device.