JP2515934Y2 - Phase breaker - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is directed to a current consumption of a detector of an open-phase circuit breaker that detects an abnormal voltage due to an open phase of a single-phase three-wire type electric circuit and interrupts the electric circuit. Technology for reducing

[Prior Art] Conventionally, an open circuit breaker having a circuit configuration shown in FIG. 3 has been used.

That is, with respect to the open-phase circuit breaker 1, 24, 25, 26 are L1, N, L2 single-phase three-wire type electric circuits on the power supply side, and 24 ', 25', 26 'are L1, N on the load side, respectively. , L2 electric circuit. The electric circuits on the power source side and the electric lines on the load side are connected by a main circuit contact 2. 50
Is a detector that is rectified by the rectifying diodes 5, 6, 7, 8 from the electric lines 24 ', 26' and is supplied with power via the voltage drop resistor 17 and the smoothing capacitor 18, and one-shot in the detector. It has both the function of detecting leakage current through the path of the circuit and output circuit, and the function of detecting abnormal voltage through the path of the waveform shaping circuit, delay circuit, and output circuit.

Since the abnormal voltage detection function is a problem here, only its operation will be described below with reference to the drawings. Reference numeral 4 denotes a neutral line open phase detection line exposed to the outside of the open phase circuit breaker 1, which is connected to the N-pole electric circuit 25 'on the load side of the open phase circuit breaker 1. Detection line 4
Is connected to the ground line via a plurality of voltage dividing resistors 20 and 21. A resistor L1 is connected across the resistor 21 connected in this way.
-N voltage and L2-N voltage are different from each other, half-wave rectified and combined, and apparently full-wave rectified to form resistors 20, 21
The voltage Vibl divided by is generated as shown in FIG. Vibl is input to the comparator 14 and compared with Vsl.
When sl is exceeded, it outputs to 15 waveform shaping circuits. Fifteen
The waveform shaping circuit always charges the capacitor 22 to the vwf voltage, but when the output from the comparator 14 is received, the voltage of the capacitor 22 is immediately discharged, and when the voltage becomes vw or less, the delay circuit 16 is driven. The capacitor 23 starts charging like Vtd. When the charging voltage of the capacitor 23 reaches a certain value vtd, the delay circuit 16 drives the output circuit and Vo is applied to the gate of the thyristor 11.
A voltage of ut is applied to turn on, an electric current is applied to the trip coil 3 to trip the main circuit contact 2, and the connection between the power supply side and the load side is cut off. In the above-mentioned operation, Vsl is set higher than Vibl in the state where the voltage between L1-N and L2-N is evenly applied, so that the comparator 14 does not generate an output. When the N-pole circuit is disconnected in the power circuit on the power supply side from the connection point of the detection line 4 and the phase becomes open, the load impedance imbalance causes the voltage between L1−N and L2−N on the load side to become unbalanced. Then Vibl exceeds Vsl as shown in the right half of Fig. 4. Once Vibl exceeds Vsl, the charging voltage Vwf of the capacitor 22 is discharged to OV, and the capacitor 23 becomes Vtd.
However, even if Vibl falls below Vsl and the capacitor 22 starts to charge like Vwf again, Vibl rises above Vsl again before Vwf reaches Vw, at which point Vwf is reached again.
Is discharged to OV, and this is repeated thereafter, and Vwf finally becomes Vw
The capacitor 23 continues to be charged like Vtd until it reaches vtd, and finally reaches vtd, the delay circuit drives the output circuit, and the output circuit outputs Vo to the gate of the thyristor 11.
The voltage of ut will be applied.

Reference numeral 13 is a constant current circuit that supplies a current determined by the value of the resistor 19 to the capacitors 22 and 23.

[Problems of conventional technology]

In the above, the resistor 19 and the constant current circuit 13 are connected inside the detector 50 as shown in FIG. 5, and the constant current determined by the resistor 19 is a transistor when the charging voltage of the capacitor 22 is charged above a certain level. 102 turned on, resistor 10
4. The current flows through the earth line through the path of the transistor 102, and its current is inversely proportional to the resistance value of the resistor 19. Here, the detection level across the voltage dividing resistor 21 is the transistor 101.
When the base ON potential of the transistor 101 is exceeded, the collector-emitter of the transistor 101 is turned on, the charging voltage of the capacitor 22 is discharged, and the transistor 102 is turned off.
A charging current is supplied from the constant current circuit 13 to a current determined by the resistor 19. The charging voltage of the capacitor 23 is vt in FIG.
If the voltage across the resistor 21 drops from the on-base potential of the transistor 101 before reaching d, the collector-emitter of the transistor 101 is turned off, but at that time the capacitor 22 is already discharged. The transistor 102 does not turn on, the capacitor 23 is continuously charged, the capacitor 22 is also charged, and when the capacitor 22 reaches the base ON potential of the transistor 102, the transistor 102 is turned on.
Is turned on, and the current generated by the constant current generating circuit 13 again flows through the transistor 102 to the ground line. As described above, according to the circuit configuration of the conventional open-phase circuit breaker, the constant current generating circuit 13 constantly generates the constant current determined by the resistor 19 until the circuit breaker detects the abnormal voltage of the electric circuit and trips the main circuit contact 2. It occurred and consumed the current somewhere, and the power consumption of the detector 50 was large.

[Object of the device and means for achieving the object]

In view of the above points, in the present invention, a large abnormal voltage with respect to Vsl is generated across the resistor 21, the waveform shaping circuit 15 discharges the charging voltage of the capacitor 22, and the delay circuit 16 causes the capacitor 23 to discharge.
It is an attempt to reduce the power consumption by keeping the current generated by the constant current generation circuit 13 small until the start of the charging of the battery.Therefore, in the present invention, the resistance 19 is always a very large value. When a resistor is inserted to suppress the current generated by the constant current generating circuit 13 to a small amount, the capacitor 22 is discharged and charging of the capacitor 23 is started, a resistor is connected in parallel with the resistor 19 and the constant current generating circuit 13 generates. Make sure that the resistance value that determines the current is almost the same as the resistance value of the resistor 19 in the conventional circuit so that the charging of the capacitor 23 is started and the charging voltage Vtd does not affect the time to reach vtd in FIG. It is configured to reduce power consumption at all times.

[Explanation of the embodiment of the invention]

FIG. 1 is a circuit diagram of one embodiment of the open-phase circuit breaker of the present invention, in which a resistor 31 having a very large resistance value is arranged in place of the resistor 19 of FIG. The connection point between the resistor 31 and the constant current generating circuit 13 is connected to the charging voltage end of the capacitor 22 by the resistor 32. Further, the values of the resistors 31 and 32 are selected so that they have substantially the same value as the conventional resistor 19 when connected in parallel.

The operation of the constant current circuit 13 of the open circuit breaker connected as described above will be described with reference to FIG.

First, when the voltage exceeding Vsl is not generated across the resistor 21 at all times, since the transistor 101 is off, the capacitor 22 is charged by the constant current generating circuit 13, and the connection point of the constant current circuit 13 and the resistor 31. The impedance between the earth line and the ground line is almost equal to the resistance 31, and the resistance 31 is a very high resistance, so the current generated by the constant current circuit 13 is also very small. It flows into the earth line through 102. Next, when the voltage across the resistor 21 exceeds Vsl, the transistor 101 is turned on, the capacitor 22 is discharged, and the potential at the charging voltage end of the capacitor 22 is reduced to almost the voltage of the ground line by the transistor 101. In parallel with the resistor 31, it will be between the connection point of the resistor 31 and the constant current circuit and the ground line, and the parallel resistance value of the resistor 32 and the resistor 31 is selected to be almost the same as the conventional resistor 19, The current value generated by the constant current circuit 13 is the same as that in the conventional case of FIG. 3, and since the capacitor 23 is charged by the current, the time from when the charging of the capacitor 23 is started to when it reaches vtd in FIG. Conventional third
It is the same as the circuit in the figure.

[Action and effect]

As described above, according to the present invention, the first capacitor 22
And a second capacitor 23 and a constant current is supplied to the charge / discharge switch circuit of the first capacitor 22 and the second capacitor 23, which is composed of the transistors 101 and 102, and the current value is between the constant current circuit and the earth line. It has a constant current circuit that decreases when the resistance value is large depending on the resistance value and increases when the resistance value is small. When an abnormal voltage is detected, the first capacitor 22 that was in the charged state up to that point is almost grounded. Is discharged until the charging voltage of the first capacitor becomes equal to or lower than the first threshold value, charging of the second capacitor is started, and the charging voltage of the second capacitor reaches the second threshold value. At this time, in the open-phase circuit breaker that triggers the thyristor to energize the trip coil to trip the main circuit contact, connect a high resistance 31 between the constant current circuit and the earth line,
A second resistor 32 is connected to the connection point of the constant current circuit and the resistor 31 and the charging voltage end of the first capacitor 22, and the resistor 31 and the resistor 32 are connected.
The parallel resistance value of the second resistor 32 is set so that the time required for the second capacitor 23 to start charging and the charging voltage to reach the second threshold value becomes a desired time. Therefore, while the normal voltage that does not charge the second capacitor 23 is generated in the circuit, the current generated by the constant current circuit is suppressed to a very small value by the resistor 31, and the power consumption of the circuit breaker can be reduced accordingly. , Abnormal voltage is generated in the electric circuit
When the charging voltage of the capacitor 22 of the above is reduced to almost the earth line voltage, the constant current circuit uses the parallel resistance value of the resistors 31 and 32 to increase the current of the second capacitor 23 to the second threshold value in the required time. It has an effect that can be generated.

[Brief description of drawings]

FIG. 1 ... Circuit configuration diagram of one embodiment of the open phase circuit breaker of the present invention, FIG. 2 ... Main circuit diagram related to the present invention of FIG. 1, FIG. 3 ... Conventional open phase breaker Fig. 4 Fig. 4 ...... Operation time chart of the conventional open-phase circuit breaker, Fig. 5 ...... Fig. 3 Main circuit diagram related to the present invention, 13 ...... Constant current circuit, 15 ... ... Waveform shaping circuit, 16 ... Delay circuit, 22 ... First capacitor, 23 ... Second capacitor, 31 ... First resistance, 32 ... Second resistance, 101 ... Transistor (first Capacitor charging / discharging switch means), 102 ... Transistor (second capacitor charging / discharging switch means).

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masaharu Aoki 3-42 Dashu, Minami-ku, Hiroshima City, Hiroshima Prefecture Temporary Industrial Co., Ltd. (72) (72) Tetsuo Furumoto 3-chome, Oshu, Minami-ku, Hiroshima City, Hiroshima Prefecture No. 1-42 Examiner at Tempar Industrial Co., Ltd. Shinichi Yajima

Claims (1)

(57) [Scope of utility model registration request] 1. An abnormal voltage is detected, and the first capacitor, which has been in a charged state up to that point, is discharged to almost the ground line voltage, and the charged voltage of the first capacitor has dropped below a first threshold value. A waveform shaping circuit that detects an electric current and generates an output, and the output of the waveform shaping circuit charges a second capacitor that has been in a discharged state until then, and the charging voltage of the second capacitor reaches a second threshold value. And a delay circuit for driving the output circuit when the voltage reaches the thyristor, the thyristor is triggered by the output voltage of the output circuit to turn on the thyristor, the trip coil is energized to open the main circuit contact, and
And a second capacitor, and a constant current circuit for supplying a constant current to the charge / discharge switch circuit of the first capacitor and the second capacitor in the waveform shaping circuit and the delay circuit, and the constant current circuit is generated. The current value to be set is set to a small value when the resistance value is large by the resistance connected between the constant current circuit and the earth line, and is set to a large value when the resistance value is small. A first resistor having a large resistance value is attached to, and between the connection point between the first resistor and the constant current circuit and the first capacitor,
When connected in parallel with the first resistor, the parallel resistance value is such that the second resistor is connected so that the time required for the capacitor 23 to start charging and reach the second threshold value can be set to a desired time. Phase breaker characterized by.