JPH03159522A - Time delay leak detector - Google Patents

Abstract

PURPOSE:To easily achieve an inertia insensitive function required for a time delay leak detector by coupling the detecting section of a leak detecting function section and the time delay circuit section of an abnormal voltage detecting function section in a complex function leak detector having leak and abnormal voltage detecting functions. CONSTITUTION:A time delay leak detector comprises a leak detecting section for comparing the secondary output voltage from a zero-phase current transformer with a reference value at a comparator 3 and producing an output if the secondary output voltage is higher than the reference value, and a time delay circuit section. A complex function detector, i.e. an integrated circuit 33, for detecting leak and abnormal voltage through said circuitry is employed, driving of the output of an output circuit 5 through a one-shot circuit 5 due to leak is prevented, a capacitor 14 is discharged by the output from the comparator 3 and a delay circuit 15 is operated so that an output circuit 6 is driven after a delay time determined by a resistor 9 and a capacitor 16 and a thyristor 17 is turned ON. By such arrangement, accuracy and stability of delay time are improved and inertia insensitivity is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Prior Art] Conventional earth leakage circuit breakers have a 0. There is a high-speed type that trips the main circuit within 1 second, and a delayed type that operates in 0.2 seconds or more.The high-speed type also has an earth leakage single 81 function type and a composite type that detects both earth leakage and abnormal voltage. There are both I-type and
Each was manufactured using its own detection λU circuit and components.

[Problems with conventional technology]

As a result, the number of types of parts has increased, and parts management has become extremely complicated.

Furthermore, time-delayed earth leakage detectors are required to have inertial non-operation performance, meaning that they must not operate unless a specified amount of earth leakage continues for a certain period of time. Many of them have a very long constant to operate with an integral voltage, and the delay time simply depends on the CR time constant, and if σj1, the stability and degree of ti are lacking due to fluctuations in the power supply voltage, etc. There was a problem.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and its purpose is to configure a time-delay type earth leakage detector with good delay time accuracy and stability and inertial non-operation performance. Furthermore, the integrated circuit 8, which is a main component of the earth leakage detection circuit, is shared by the time-delay type and the multi-function type which operates under both earth leakage and abnormal voltage, thereby reducing the number of parts.

[Means used to achieve the purpose]

This invention consists of an earth leakage detection section that compares the secondary output voltage of the zero-phase current transformer with a reference value using a comparator, and generates an output if it exceeds the reference value, and an earth leakage detection section that outputs an intermittent output. A time delay circuit section that has an inertial non-operating performance that continuously charges the time delay capacitor with a constant current and generates an output when the charging voltage of the capacitor reaches a certain constant value. The time delay circuit section includes a capacitor separate from the time delay capacitor, which is constantly energized to charge and satisfies a reference charging voltage, and is connected to a capacitor separate from the time delay capacitor, which is continuously and intermittently generated by the output of the earth leakage detection section. The time delay capacitor is continuously charged with a constant current on the condition that the reference charge TL voltage is not reached by charging and discharging while the voltage is lower than the reference charging voltage. When the charging voltage reaches a certain value, the output is 5! a
If the output of the earth leakage detection part stops occurring before the delay time is reached, the separate capacitor is stopped from discharging and charged to the reference voltage by the charging force, and the charging voltage is increased. When the time delay capacitor reaches the reference voltage, the charging voltage of the time delay capacitor is discharged so that no output is generated from the output circuit, thereby providing inertial non-operation performance.

Furthermore, the above leak? [i The detection section and the time delay circuit section are the detection section of the earth leakage detection function section and the time delay circuit of the abnormal voltage detection function section of the multifunctional earth leakage detector collection Ka that has both earth leakage and abnormal voltage detection functions. By combining the parts, the above-mentioned concentrating circuit can be used in reverse for a time-delay type stone detector.

Figure 4 works with both conventional lightning leaks and abnormal voltages. X
This is an example of the circuit configuration of the i7i detector. Here, 33 is configured as an integrated circuit, and 2, 3. 5 is a circuit for detecting electric leakage (consisting of blocks 8, 10, 13.
15 is a circuit configuration block for detecting abnormal voltage;
Figure 5 shows the voltage waveforms of various parts when detecting earth leakage, and Figure 6 shows the voltage waveforms of various parts when detecting abnormal voltage. In the above-mentioned circuit configuration example, to first explain the earth leakage detection operation, the zero-phase current transformer 1 is
The secondary output voltage Vilk generated in VMM is aat
When the tt value reaches vn+m, the one-shot circuit 5 operates and drives the output circuit 6 for a time period of Lout. Vou
The thyristor 17 is triggered by the output voltage of t, the trip coil 24 is energized, and the main circuit contact opening/closing b1 structure 25 is r'
: i Drive.

Next, to explain the abnormal voltage detection operation, the main circuit line
l? i34, 35.36, each single-phase three-wire voltage Ll,
Assume that the positives of N and L2 are connected. Ll
The voltage on the side is half-wave rectified by the diode 2l through the resistor 12 and the resistor l1, and then supplied to the resistor 11.The voltage on the L2 side is half-wave rectified by the diode 22 through the resistor l2 and the resistor 1l, and is supplied to the resistor 11. Supply voltage Vi from
bl is a full wave in which the voltages between Ll-N and N-L2 are equal, that is, the height of each voltage peak is equal, as shown in the left half of Vil+l in Fig. 6 in the normal case! ! It has a flow waveform. Here, due to some reason, Ll-N. N
- The voltage balance between L2 is disrupted, that is, the neutral Fi of the main circuit line! When N is in an open phase state, Vibl becomes the sixth
As shown in the right half of the figure, the waveform looks like alternating high peaks and low peaks. This Vibl is input to one side of the comparator 10 in FIG. 4 and is compared with the reference voltage vb+t. Vbl
t is as shown in FIG. It is set to the voltage that cuts the high peak when the voltage balance between N-L2 collapses, and the 6th
In the normal state shown in the left half of the figure, no output is generated from the comparator IO. When Vibl exceeds v bat, the output of the comparator lO causes the l30 waveform shaping circuit to discharge the 14 capacitors that had been charged and maintained the reference voltage of Vνf, and the charging potential of the 14 capacitors drops from vvf. 13 waveform shaping circuits drive 15 delay circuits, and the delay circuits charge a 1G capacitor. The aforementioned Vi
Since there is no output from the comparator 10 while bl does not reach vbat, the waveform shaping circuit 13 charges the capacitor 14 and attempts to restore the charging voltage Vνf to vwf, but as shown in the right half of FIG. If the abnormal voltage state continues, the charging voltage Vref of capacitor l4 repeats charging and discharging and never reaches vwf, capacitor l6 continues to be charged like VLd, and when vtd reaches vtd , the delay circuit l5 drives the output circuit 6, and the output circuit 6 outputs Vout.
The thyristor 17 is triggered to turn on at a voltage of , and the trip coil 24 is energized to drive the main circuit contact opening/closing mechanism 25. Ltd in Figure 6 is the delay time, which is usually set to about 0.6 seconds. In Fig. 4, 8 is a constant current circuit that charges a capacitor 14.16 with a constant current determined by a resistor 9. Therefore, the delay time accuracy and stability of Ltd are affected by fluctuations in power supply voltage, etc. However, good results have been obtained.

The present invention uses an integrated circuit 133 of a multifunctional detector that detects both earth leakage and abnormal voltage with the circuit configuration shown in FIG.
The capacitor 14 is discharged by the output of the comparator 3, and the delay circuit is activated. After a delay time determined by the values of the resistor 9 and the capacitor 16, the output circuit 6 is driven and the thyristor 17 is turned on. This is how it was done. [Description of Embodiments of the Invention] FIG. 1 shows an embodiment of the circuit configuration of the time-delayed leakage TL detector of the present invention. The difference between FIG. 1L and FIG. 4 described above is that a diode 26, a capacitor 27, and a resistor 28 are provided in place of the capacitor 4 in FIG. resistance 9
Instead of 0, a resistor 29 and a transistor 30 are connected as shown in FIG. 1, and the base of the transistor 30 is connected to the connection point between the cathode of the diode 26, the capacitor 27, and the resistor 28. The comparator circuit 100 input terminal is grounded. A capacitor 31 is provided in place of capacitor l4,
The voltage side of capacitor 31 is connected to the collector of transistor 30 mentioned above. A capacitor 32 is provided in place of the capacitor 16, and the resistor 29 and capacitor 32 are shown as being switched as shown in FIG. The resistor 9 and capacitor 16 may be fixed.

The operation of the circuit constructed as described above and shown in FIG. 1 will now be described with reference to FIGS. 1 and 2. In FIG. 1, when the secondary output voltage Vilk of the zero-phase current transformer l is not generated or when Vilk does not reach Vlkt, the capacitor 27 is completely discharged from the resistor 2B+, and the voltage is Since it does not exist, transistor 30 is turned off. Since the transistor 30 is off, the capacitor 31 is always charged to vwf from the constant current generating circuit through the resistor 29. When Vilk is generated on the secondary side of zero-phase current transformer l from this state, Vilk is amplified by amplifier 2 and compared with V Ikt by comparator 3, and the comparison is made only when the amplified signal of V1k is lower than V lkt. Unit 3 generates an output. While there is an output from comparator 3,
Capacitor 27 is charged through diode 26, and V
When the amplified signal of ilk exceeds V Ikt, the output of comparator 3 disappears, so the charging voltage of capacitor 27 is
It is discharged through the Here, the discharge time constant due to the resistor 28 is set relatively long, so that Vi
When the amplified signal of lk is input continuously, the capacitor 27
As shown in FIG. 2, the charging voltage VMM' gradually rises while repeatedly rising and falling. VMM'
When the voltage reaches the ON voltage vmm' of the base of the transistor 300, the voltage between the collector and emitter of the transistor 30 becomes ONI.
、． , the charging voltage of the capacitor 31 is discharged at once through the transistor 30 and falls below vwf. capacitor 3
When the charging voltage of 1 falls below vwf, the waveform shaping circuit drives the delay circuit and starts charging the capacitor 32 linearly as indicated by Vtd with a constant current determined by the resistor 29.

On the other hand, the one-shot circuit 5 is set to operate when the VMM shown in FIG. 2 becomes vmm, but the diode 26
The voltage on the anode side of is the sum of the base voltage vWIm' when the transistor 30 is turned on and the voltage between the anode and cathode when the diode 26 is turned on, and since these voltages of this type of semiconductor are constant, Since it is set high, it will not operate permanently, and therefore the output circuit 6 will not be driven by the output of the one-shot circuit 5 and a trigger output will not be supplied to the thyristor 17. V
MM' reaches vmwt' and transistor 30 turns O.
During N operation, VMM' does not rise above vIllII1', and when the Vilk increase signal exceeds Vlkt, the output of comparator 3 disappears, so the charging voltage of capacitor 27 is discharged through resistor 28 and falls below vmm'. Of course. When IIM' falls below vmm', transistor 3
0 is OFFL/, and the capacitor 31 starts to be charged again through the resistor 29 as shown in FIG. When VMM' reaches vma+' again, the transistor 30 turns on and discharges the capacitor 31 again, so as long as the amplified signal of Vilk, which is less than Vlkt as shown in FIG. 2, continues to be generated, the charging voltage of the capacitor 31 ■
νF repeats charging and discharging until there is no Vilk or there is no Vilk.
The amplified signal of k never reaches Vvf, which is no lower than Vlkt. The charging voltage of capacitor 31 is vwf
Since the capacitor 32 does not reach the waveform shaping circuit 13
Due to the function of the delay circuit 15 that continues to be driven by Vt
d, the voltage is continuously charged with a constant current determined by the resistor 29, and the voltage gradually rises, reaching vtd after time ttd, and the delay circuit IN15 drives the output circuit 6, and the thyristor The trigger voltage Vout is output to the gate of the comparator 10 to turn on the thyristor l7, energizing the trip coil 24 and driving the main circuit contact opening/closing mechanism 25. Also, the input end of the comparator 10 is grounded to the earth line. Therefore, the comparator 10 operates the waveform shaping circuit l3 and a trigger signal is not generated from the output circuit 6 to the gate of the thyristor l7. If this occurs, the operation will be as described above, but if Vilk stops midway, or if the amplified signal of Vilk becomes a small value that does not fall below Vlkt, the operation will be as shown in Figure 3 (when Vilk stops). After that, the capacitor 27 is not charged and VMM' continues to be discharged by the resistor 28 and never reaches vIllff1' again. Therefore, once Vvf falls below vvf, the capacitor 31 continues to be charged through the resistor 29. , eventually reaches vvf by ¥+1, and when vvf is reached, charging of the capacitor 32 stops at that point, and VLd becomes vt
d does not reach the output signal Vou from the output circuit 6.
t does not occur.

The delay interval of the above leakage Ml circuit breaker during operation is determined by Ltd, and ttd is the resistor 29 and capacitor 3 in Fig.
The delay time can be easily changed by switching the resistor 29 and/or the capacitor 32 as shown in Fig. Also good. During the delay time ttd, the capacitor 32 is charged with a constant current generated by the constant current generating circuit 8 and determined by the resistor 29, so that a stable and highly accurate charge that does not fluctuate due to power supply voltage or other factors can be obtained. [Operations and Effects] With the above configuration, as long as the amplified signal of V ilk that is lower than V lkt continues to be generated, the capacitor 31 is
During this period, the capacitor 32 is charged with a constant current, and when the charging voltage of the capacitor 32 reaches a certain value, the output circuit 6 is driven to generate an output, so it is a time delay type. In addition, since the capacitor 32 is charged with a constant current, it is possible to easily obtain the inertial non-operation performance required for a W leakage detector, so the time delay does not change due to voltage fluctuations and is stable. The integration circuit that can obtain a good delay time at both 14A and 14A degrees and integrates the output of the comparator 3 on the earth leakage detection side consists of a CR parallel connection circuit and a diode 26 connected in the forward direction to the charge/discharge circuit of the CR parallel connection. Since the base of the transistor 300, which is an active element, is connected to the charging voltage side of the CR parallel connection circuit, the anode voltage of the diode 26 is the sum of the operating anode-cathode voltage of the diode 26 and the operating pace emitter voltage of the transistor 30. , and the operating voltage of the one-shot circuit 5 is set to a higher voltage, so the output circuit 6 can be driven through the one-shot circuit 5 by the secondary output voltage of the zero-phase current transformer l. Moreover, since the input terminal of the comparator 100 on the abnormal voltage detection side is connected to the ground line, no output is generated from the comparator, and the output of the comparator 10 is sent to the output circuit through the waveform shaping circuit 13 and the delay circuit 15 15
The capacitor 31 is discharged by the ON operation of the transistor 30 operated by the charging voltage of the integration circuit, the constant overflow circuit 7 generates a constant current, and the delay circuit 15 32 is configured to start charging with the above-mentioned constant voltage, a time-delay type 1Ti voltage detector can be constructed using a multi-functional integrated circuit that has both an earth leakage detection function and an abnormal pressure detection function, and the main F of the collector circuit which is a component! Furthermore, since the current determining resistor 29 of the constant current circuit 8 is connected to the collector of the transistor 30, the constant current generating circuit 8 is not driven at all times after charging the capacitor 31, and when a leakage is detected, the transistor 30 is activated. O
Current consumption is low because constant current is generated only when N is turned on.
By switching both or one of the current determining resistor 29 and the capacitor 320, a time-delay switching type earth leakage detector can be easily constructed.

[Brief explanation of the drawing]

Figure 1 is an embodiment of the time delay type earth leakage detector according to the present invention, Figure 2 is an operation time chart when the detector in Figure 1 generates a detection output, Figure 3 is the detector in Figure 1. Fig. 4 is an example of the circuit configuration of a conventional combined V & function type earth leakage detector that generates a detection output for both earth leakage and abnormal voltage, 7J. Figure 5 is an operation time chart when the detector shown in Figure 4 operates due to electrical leakage, and Figure 6 is an operation time chart when the detector shown in Figure 4 operates due to abnormal voltage. 1... Zero phase current transformer, 3... Comparator, 6... Output circuit, 8... Constant current generation circuit, 13... Waveform shaping circuit, 15...・Delay circuit, 26...Diode, 27...Capacitor, 28...Resistor, 29...Resistor, 30...Active element (transistor), 31●...
Capacitor, 32... Capacitor. 21st! ] Figure 3

Claims (4)

[Claims] (1) A comparator that compares the secondary output voltage of a zero-phase current transformer with a reference value and generates an output during the period when it exceeds the reference value, and an integrating circuit that connects the output voltage of the comparator in parallel with a CR. An active element that integrates and turns on when it detects that an operating value has been reached, a capacitor 31 that is normally charged to a reference charging voltage and discharged only when the active element is turned on, and a capacitor 31 that is charged. Detecting that the voltage is below the reference charging voltage, a waveform shaping circuit that generates an output, and receiving the output of the waveform shaping circuit, start charging the capacitor 32 with a current generated by a separate constant current generation circuit, A time delay type earth leakage detector comprising a delay circuit that drives an output circuit to generate a detection output when the charging voltage reaches a certain value. (2) The comparator, waveform shaping circuit, constant current generation circuit, delay circuit, and output circuit are a comparator that compares the secondary output voltage of the zero-phase current transformer with a reference value and generates an output. , an earth leakage detection function consisting of a one-shot circuit that integrates the output of the comparator, detects when the integrated value becomes a constant value and drives the output circuit, and generates an output by comparing the abnormal voltage in the electrical circuit with a reference value. a comparator that receives the output of the comparator, and a waveform shaping circuit that discharges the capacitor 31 that has been constantly charged to the reference charging voltage in response to the output of the comparator, and generates an output when it detects that the charging voltage of the capacitor 31 is lower than the reference voltage. and an abnormal voltage detection function consisting of a delay circuit that charges the capacitor 32 with a constant current generated by a separate constant current generation circuit in response to the output of the waveform shaping circuit, and drives the output circuit when the charging voltage reaches a constant value. A comparator on the earth leakage detection function side, a waveform shaping circuit on the abnormal voltage detection function side, a constant current generation circuit, a delay circuit, and an output circuit of the integrated circuit for the earth leakage and abnormal voltage detection type multi-function detector, which has The time delay type earth leakage detector according to claim (1), characterized in that: (3) The integrating circuit is a charging/discharging circuit in which CRs are connected in parallel, and diodes connected in the direction of supplying charging current are connected in series, and the active element is a transistor, and the base of the transistor is connected in parallel with the CRs. It is connected to the connection point between the circuit and the cathode of the diode, the emitter of the transistor is connected to the earth line side, and the collector is connected to the current determining resistor 29 of the constant current generating circuit and the charging voltage side of the capacitor 31. The operating voltage of the one-shot circuit is set higher than the potential on the anode side of the diode of the integrating circuit when the transistor is turned on, and the input terminal of the comparator of the abnormal voltage detection function example is connected to the earth line to detect the leakage current. The time delay type according to Claims (1) and (2), characterized in that the output of the comparator on the detection function side is connected to the waveform shaping circuit on the abnormal voltage detection function side. Earth leakage detector. (4) Time-delayed earth leakage detection according to claim (1), characterized in that either or both of the current determining resistor 29 and the capacitor 32 of the constant current generating circuit are switched. vessel.