JPH0379936B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an earth leakage breaker that can be used commonly in power supply systems with different voltages.

[Technical background of the invention and its problems]

Some circuit breakers have the primary function of responding to earth leakage accidents, and are usually referred to as earth leakage breaker. A conventional earth leakage breaker will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows the circuit configuration of a conventional earth leakage breaker applied to a 100 to 200 [V] power supply system. In FIG. 1, a power source 1 is connected to a load 4 by a main circuit conductor 3 having main circuit contacts 2, thereby forming a main circuit. Further, the main circuit conductor 3 is connected to an input end of a full-wave rectifier 5 consisting of a diode. A smoothing capacitor 6 is connected in parallel to the output terminals P ₁ and N ₁ of the full-wave rectifier 5. The above full wave rectifier 5, capacitor 6
constitutes a control power supply section. Further, a series circuit consisting of a resistor 7, a tripping coil 8 and a thyristor 9 is connected in parallel to the output terminals P ₁ and N ₁ .

On the other hand, 10 is a zero-phase current transformer whose primary side is the main circuit conductor 3, and when a leakage fault occurs in the load 4 and a leakage current flows through the main circuit conductor 3, a leakage detection current is generated on the secondary side. is detected. This zero phase current transformer 10
The secondary side of the control circuit 11 is connected to signal input terminals A and B of the control circuit 11, respectively.

Further, the control circuit 11 has a control power input terminal P ₂ ,
The output terminal P ₁ of the full-wave rectifier 5 is connected to the control power input terminal P ₂ via the resistor 12, and the control power input terminal N ₂ is connected to the output terminal N ₁ so that the DC power supply is connected to the control power input terminal P ₂ . Supplied. Furthermore, this control circuit 11
has a signal output terminal S, to which the gate of the thyristor 9 is connected. The control circuit 11 described above sends a trigger signal from the signal output terminal S to the gate of the thyristor 9 when a detection current flows to the secondary side of the zero-phase current transformer 10 and this detection current exceeds a predetermined value. It has the function of outputting an output, turning on the thyristor 9, and energizing the tripping coil 8. When the trip coil 8 is energized, a trip mechanism (not shown) is driven and the main circuit contact 2 is opened.

Further, one end of a series circuit consisting of a resistor 14 as an impedance element and a push button switch 13 is connected to one end of the main circuit conductor 3, and the other end is connected to the main circuit as the primary side of the zero-phase current transformer 10. circuit conductor 3
connected to the other. This configuration constitutes an operation test section. Note that 15 is a surge absorption element provided between the primary side wires of the full-wave rectifier 5.

Next, the operation of the earth leakage breaker configured as described above will be described. That is, the full-wave rectifier 5 and smoothing capacitor 6 that form the control power supply section have a rating and capacity corresponding to the main circuit voltage, and are connected to a series circuit consisting of a resistor 7, a tripping coil 8, and a thyristor 9, and a control circuit 11. It supplies DC power. In this state, when a leakage fault occurs in the load 4 and a leakage current flows through the main circuit conductor 3, a leakage detection current flows through the secondary side of the zero-phase current transformer 10. If this detected current exceeds a predetermined value, the control circuit 11 determines that an earth leakage accident has occurred, outputs a trigger signal from the signal output terminal S, and turns on the thyristor 9. The tripping coil 8 is then energized, the main circuit contact 2 is opened, and the tripping is completed.

On the other hand, when the push button switch 13 of the operation test section is closed, a part of the main circuit current is passed through the resistor 14 to the primary side of the zero-phase current transformer 10 as a simulated earth leakage current. As a result, an earth leakage detection current flows through the secondary side of the zero-phase current transformer 10. Due to this detected current, the main circuit contact 2 is opened as in the case of the actual earth leakage accident described above. It is confirmed that the earth leakage breaker's earth leakage accident response function works normally.

In addition, in this earth leakage breaker, a thermal relay (not shown) operates to open the main circuit contact 2 in the event of an overcurrent accident, and an electromagnet (not shown) operates to open the main circuit contact 2 in the event of an instantaneous operation such as a short circuit. Open circuit contact 2.

In the earth leakage breaker mentioned above, for example, if the power supply voltage is
The value of the resistor 12 is selected so that a DC power supply of a predetermined voltage is supplied to the control circuit 11 so that the earth leakage accident response function can function normally even when the voltage drops from 100V to about 60V.

Therefore, if the above earth leakage breaker is used in a power supply system of 200 to 415 [V], the power consumption of the resistor 12 and the resistor 7 will be very large, and the full-wave rectifier 5 and The capacitor 6 is required to have a large withstand voltage and capacity, which requires a large space, leading to an increase in cost.

Next, an earth leakage breaker used in a 200 to 415 [V] power supply system will be explained with reference to FIG.

In FIG. 2, parts that are the same as those in FIG. 1 are given the same reference numerals, and their explanation will be omitted, and only the different parts will be explained. In FIG. 2, the primary winding of the transformer 16 is connected to the main circuit conductor 3, and the input terminal of the full-wave rectifier 5 is connected to the secondary winding, thereby reducing the main circuit voltage and total The wave rectifier 5 is supplied with an AC secondary output.

In addition, a series circuit consisting of a resistor 7, a tripping coil 8, and a thyristor 9 is connected to the output terminals P ₁ and N ₁ of the full-wave rectifier 5.
is connected to. Furthermore, push button switch 13, resistance 1
The operation test section consisting of 4 is connected between the secondary windings of the transformer 16 to supply an alternating current obtained by stepping down the main circuit voltage.

The earth leakage breaker configured as described above has a tripping coil 8 for the earth leakage breaker of the 100 to 200 [V] power supply system shown in FIG. The difference is that the main circuit voltage is stepped down by a transformer 16 and then supplied to the full-wave rectifier 5 in order to supply a DC power source of the same voltage as in the case of the converter. Therefore, the earth leakage accident response function and operation test function are the same as those of the earth leakage breaker shown in FIG. 1, so the explanation of the operation will be omitted.

Now, the earth leakage breaker mentioned above has a rated voltage of 100
The case where it is applied to a power supply system of ~200 [V] will be described. In this case, even if the main circuit voltage drops to about 60V, it is necessary to output constant voltage DC power from the control power supply section. Therefore, if the number of turns of the secondary winding of the transformer 16 is increased,
When applied to a power supply system of ~415 [V], the secondary output of the transformer 16 becomes large. However, the load on the control power supply section is constant, and in order to supply constant voltage DC power, the capacity of the full-wave rectifier 5,
Each of the smoothing capacitors is required to have a high withstand voltage, and the power consumption of the resistor 12 becomes large, requiring a large space, leading to an increase in cost.

As mentioned above, in the earth leakage breaker shown in Fig. 1 and Fig. 2,
Considering that it is used in common with a 415V power supply system, the capacity of the full-wave rectifier 5 and the withstand voltage of the smoothing capacitor 6 are required to be large, and the power consumption of the resistors 7 and 12 also becomes large. Sharing was impossible.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
It is an object of the present invention to provide an earth leakage breaker that is small in size and simple in configuration and can be used commonly in high and low voltage power supply systems.

[Summary of the invention]

In order to achieve the above object, the earth leakage breaker according to the present invention is characterized by being configured as follows. That is, a voltage converter outputs the main circuit voltage as a plurality of different voltages, and a switchable first rectifier is provided to input a part of the output voltage of the voltage converter, and the remaining output voltage is is input to the second rectifier, the voltage output from the rectifier circuit consisting of the first and second rectifiers is detected by a voltage detection circuit, and if this detected voltage value exceeds a predetermined value, The first rectifier is configured to be switched off.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a circuit configuration diagram showing the first embodiment of the earth leakage breaker according to the present invention, and FIG.
The same parts as those in the figure are given the same reference numerals.

In FIG. 3, 17 is a transformer as a voltage converter, which has a primary winding 17A and a secondary winding 17B having a winding start tap 17B _s , an intermediate tap 17B _t , and an end winding tap 17B _e . have.
Both ends of the primary winding 17A of the transformer 17 are connected between the lines of the main circuit conductor 3, and the surge absorbing element 15
is connected. Further, the anode of the first light-triggered thyristor 18A _{1 and the cathode of the second light-triggered thyristor 18A 2 are} connected to the winding start tap 17B _s of the secondary winding 17B. The first and second light-triggered thyristors 18A ₁ and 18A ₂ are first rectifiers, and the light-emitting elements for triggering the light-receiving elements are first and second light-emitting diodes 18B ₁ and 18B, which will be described later. ₂
These are configured as a photocoupler 18.

The intermediate tap 17B _t of the secondary winding 17B has the first
The anode of the second diode 19D ₁ is connected, and the cathode of the second diode 19D ₂ is connected.

The anode of a third diode 19D ₃ and the cathode of a fourth diode 19D ₄ are connected to the winding end tap 17B _e of the secondary winding 17B. These first to fourth diodes 19D ₁ to 19D ₄ constitute a second rectifier. The cathodes of the first light-triggered thyristor 18A ₁ and the first and third diodes 19D ₁ and 19D ₃ are connected in common, and one end of the capacitor 6 is connected to the output terminals of the first and second rectifying sections. _P1
It is becoming. In addition, the second optically triggered thyristor 18A ₂ and the second and fourth diodes 19D ₂ , 1
The anodes of _9D4 are connected in common, and the other end of the capacitor 6 is connected to serve as the output end _N1 of the first and second rectifying sections. A series circuit consisting of a tripping coil 8 and a thyristor 9 is connected to the output terminals P ₁ and N ₁ of the first and second rectifying sections. On the other hand, the output terminal _P1 has the emitter of the first transistor (PNP type) _20T1 and the first resistor 20T1.
One end of _R1 is connected. The collector of the first transistor 20T ₁ is connected to the base of the second transistor (NPN type) 20T ₂ via a second resistor 20R ₂ . first transistor 20
The cathode of a voltage regulator diode 20Z is connected to the base of T ₁ via a third resistor 20R ₃ , and its anode is connected _to the second
The collector of the transistor 20T2 is connected to the collector of the transistor _20T2 . The collector of the second transistor 20T ₂ is connected to the anodes of the first and second photodiodes 18B ₁ and 18B ₂ forming a series circuit in the forward direction, and the cathode thereof is connected to the collector of the second transistor 20T 2 .
It is connected to the output terminal _N2 together with the emitter of _0T2 . The first and second transistors 20T ₁ , 2
0T ₂ , first, second and third resistors 20R ₁ , 20R ₂ ,
20R ₃ , the constant voltage diode 20Z, and the first and second light emitting diodes 18B ₁ and 18B ₂ constitute a voltage detection circuit. Further, the voltage detection circuit uses the emitter of the first transistor 20T ₁ and one end of the first resistor 20R ₁ as an input terminal P ₃ , and the emitter of the second transistor 20T ₂ and the first and second light emitting diodes 18B ₁ and 18B. ₂ cathode is input terminal N ₃
It is said that First and second light emitting diodes 18
B ₁ , 18B ₂ are the aforementioned optical trigger type thyristors 1
Together with 8A ₁ and 18A ₂ , it is configured as a photocoupler 18.

On the other hand, the secondary side of the zero-phase current transformer 10 with the main circuit conductor 3 as the primary side is connected to the signal input terminals A and B of the control circuit 11.
are connected to each other. Further, the control power input terminal P ₂ of the control circuit 11 is connected to the output terminal P ₁ of the rectifier circuit via the resistor 12, and the control power input terminal N ₂ of the control circuit 11 is connected to the output terminal N ₁ of the rectifier circuit. It is connected. Further, the control circuit 11 has a signal output terminal S.
The gate of the thyristor 9 is connected to this, and a leakage detection current flows to the secondary side of the zero-phase current transformer 10, and when this detection current exceeds a predetermined value,
It has a function of outputting a trigger signal from the signal output terminal S to the gate of the thyristor 9, turning on the thyristor 9, and energizing the tripping coil 8. When this tripping coil 8 is energized, a tripping mechanism (not shown) is driven and the main circuit contact 2 is opened. The above-mentioned tripping coil 8, thyristor 9,
The zero-phase current transformer 10, the control circuit 11, the resistor 12, and a tripping mechanism (not shown) constitute an earth leakage accident response section.

Note that when the first and second light emitting diodes 18B ₁ and 18B 2, which are light emitting elements, are turned on, the photocoupler 18 optically triggers the first and second light-triggered thyristors 18A ₁ and 18A ₂ , which are light receiving elements _. This is what turns it on. Note that a resistor 21R 1 and a capacitor ₂₁ are connected between the gate of the first light-triggered thyristor 18A ₁ and the output terminal P ₁ of the rectifier circuit.
A first gate circuit consisting of C ₁ is connected and a second
The gate of the light-triggered thyristor 18A ₂ and the winding start tap 17 of the secondary winding 17B of the transformer 17
A _second gate circuit consisting of a resistor 21R ₂ and a capacitor 21C ₂ is connected between the resistor 21R 2 and the capacitor 21C 2 . In the gate circuit, the resistors 21R ₁ and 21R ₂ are for electrically reinforcing the optical trigger signals from the first and second light emitting diodes 18B ₁ and 18B ₂ , and are usually 10 k[Ω] to 33 k[Ω]. It has a high resistance value of Ω]. In addition, the trigger sensitivity of the capacitors 21C ₁ and 21C ₂ is reinforced by the resistors 21R ₁ and 21R ₂ ,
This prevents the dv/dt tolerance from decreasing. Therefore, if no optical trigger signal is input to the first and second optically triggered thyristors 18A ₁ and 18A ₂ , the first and second optically triggered thyristors 1
Even if the voltage rise between the anode and cathode of 8A ₁ and 18A ₂ exceeds the critical value (dv/dt tolerance) of a single element, it will not turn on.

Next, the operation of this embodiment configured as above will be explained. First, the power supply system is 100 to 200
The case where it is applied to a [V] power supply system (low voltage) will be described. That is, in the initial state, the first and second optically triggered thyristors 18A ₁ and 18A ₂ are off. A low main circuit voltage is applied to the primary winding 17A of the transformer 17, and a voltage of 2.0 mm is applied between the intermediate tap 17B _t and the end tap 17B _e of the secondary winding 17B, which corresponds to the low main circuit voltage. The next voltage is output, and the first
It is rectified by the fourth diodes 19D ₁ to 19D ₄ and smoothed by the capacitor 6, and the output terminal P ₁ ,
A DC power supply of voltage E ₁ is output from N ₁ . At this time, the voltage E ₁ between the output terminals P ₁ and N ₁ is the voltage VB between the emitter and base of the first transistor 20T ₁ of the voltage detection circuit, the Zener voltage VZ of the voltage regulator diode 20Z, and the first and second transistors. 2 light emitting diode 1
Addition value to forward voltage drop VL of 8B ₁ and 18B ₂
When it is lower than VTH (VTH=VB+VZ+VL), no base current flows through the first transistor _20T1 . For this reason, the first transistor 20T ₁ is turned off, and since no base current flows through the second transistor 20T ₂ , the second transistor 20T ₂ is also turned off. Therefore, a part of the DC current output to the output terminals P ₁ and N ₁ flows through the first resistor 20R ₁
via the first and second light emitting diodes 18B ₁ ,
18B ₂ , first and second light emitting diode 1
Turn on 8B ₁ and 18B ₂ . Photocoupler 18
When the first and second light-emitting diodes 18B ₁ and 18B ₂ as light-emitting elements are turned on, the first and second light-triggered thyristors 18A 1 and 18B ₂ as light-receiving elements are turned on.
_18A2 is turned on in conjunction with the action of the trigger circuit.

By the above operation, the secondary winding 17B of the transformer 17
The secondary voltage induced between the winding start _{tap 17Bs} and _the winding _end tap _17Be of It is rectified by _19D4 , smoothed by capacitor 6, and outputs a DC power of voltage _E2 to output terminals _P1 and _N1 .

Next, a case where the present invention is applied to a power supply system (high voltage) of 200 to 415 [V] will be described. That is, in the initial state, the first and second light-triggered thyristors 18A ₁ ,
18A ₂ is off. Primary winding 1 of transformer 17
A high main circuit voltage is applied to 7A, and the middle tap _17Bt and end tap 17 of the secondary winding 17B are
A secondary voltage corresponding to the high main circuit voltage is output between B _e and the first to fourth diodes 19
It is rectified by D ₁ to 19D ₄ and smoothed by a capacitor 6, and a DC power source of voltage E ₃ is output from output terminals P ₁ and N ₁ . At this time, the voltage between output terminals P ₁ and N ₁
E ₃ is the added value in the voltage detection circuit mentioned above.
When the voltage is higher than VTH, the first and second transistors 20T ₁ and 20T ₂ are turned on. In this case, the voltage V _CE between the collector and emitter of the second transistor 20T ₂ is equal to the voltage V CE between the first and second light emitting diodes 1
Since the forward voltage drop VL of 8B ₁ , 18B ₂ is much lower than the forward voltage drop VL of 8B 1 , 18B 2 , a part of the DC current from the output terminals P ₁ , N ₁ is transferred to the first and second light emitting diodes 18B ₁ , 1
8B ₂ is not energized, but flows to the second transistor 20T ₂ via the first resistor 20R ₁ . Therefore, the first and second light emitting diodes 18B ₁ and 18B ₂ which are light emitting elements of the photocoupler 18 are not turned on, and the first and second light trigger type thyristors 18A ₁ and 18A ₂ which are light receiving elements are not turned on. Therefore, the intermediate tap 17 is connected to the secondary winding 17B of the transformer 17.
2 induced between B _t and winding end tap 17B _e
The next voltage is applied to the first to fourth diodes 19D ₁ to 19D ₄ . Then, it is smoothed by a capacitor 6, and a DC power source of voltage _E3 is output from the output terminals _P1 and _N1 .

Next, the power supply system changes from 100 to 200 [V] (hereinafter referred to as low voltage) to 200 to 415 [V] (hereinafter referred to as high voltage).
Furthermore, the operation when the voltage changes from 200 to 415 [V] to 100 to 200 [V] will be described. That is, the first and second photo-triggered thyristors 18A ₁ ,
18A ₂ is turned on, and the output terminals P ₁ and N ₁ are connected to transformer 1.
A DC power source of voltage E ₂ corresponding to the secondary voltage induced between the winding start tap 17B _s and the winding end tap 17B _e of the secondary winding 17B of No. 7 is output.

Next, when the main circuit voltage gradually increases from 100 to 200 [V] to 200 to 415 [V], the output terminals P ₁ , N ₁
When the voltage value of increases and exceeds the addition value VTH in the voltage detection circuit, the first and second transistors 20T 1 and 20T 2 are turned on, and the first and second transistors 20T ₁ and 20T ₂ are turned on.
The light emitting diodes 18B ₁ and 18B ₂ are turned off.
As a result, the first and second optically triggered thyristors 18A ₁ and 18A ₂ are turned off, and the output terminals P ₁ and N ₁
A DC power supply having a voltage _E3 corresponding to the secondary voltage induced between the intermediate tap _17Bt and the end tap _17Be of the secondary winding 17B of the transformer 17 is output. This is because the reverse voltage is the first and second in the power supply system.
This occurs when the voltage is applied to the optically triggered thyristors 18A ₁ and 18A ₂ .

Next, a case will be described in which the voltage of the main circuit gradually decreases from 200 to 415 [V] to 100 to 200 [V]. That is, in this case, from 200 to 415 [V] to 100 to
The first and second light emitting diodes 18B ₁ and 18B ₂ will not turn on unless the voltage drops to 200 [V] and further reaches the voltage VTL. This is due to the fact that the voltage detection circuit has hysteresis characteristics. In this case, the forward voltage drop VL of the first and second light emitting diodes 18B ₁ and 18B ₂ connected in series is utilized as the hysteresis voltage width of the hysteresis characteristic shown by VTH−VTL=VH shown in FIG. There is.

Here, the voltage of the main circuit is 200, which is a high voltage value.
~415 [V], passes through the voltage value (200 [V]) corresponding to VTH in Fig. 4, and then
Voltage value corresponding to VTL in the figure (weak 200 [V])
The process of reaching a low voltage value of 100 to 200 [V] will be explained.

That is, at high voltage values, transistor 20
Since T ₂ is in the on state, a current-carrying path passing through the resistor 20R ₁ and the collector and emitter of the second transistor 20T ₂ is formed. At this time, the first and second transistors 20T ₁ and 20T ₂ are both on, and the first and second light emitting diodes 18B ₁ and 1
8B ₂ are both off. This is because, as already mentioned, the voltage V _CE between the collector and emitter of the second transistor 20T ₂ is much smaller than the forward voltage drop VL of the first and second light emitting diodes 18B ₁ and 18B ₂ . It's based on that.

Next, the main circuit voltage is changed from the voltage value (200 [V]) corresponding to VTH in Fig. 4 to
Between the voltage values corresponding to VTL (weak 200 [V]), the voltage V _CE between the collector and emitter of the second transistor 20T ₂ is the same as that of the first and second light emitting diodes 18B ₁ and 18B. As long as the forward voltage drop VL of ₂ is below, the input voltage to the voltage detection circuit will be below VB + VZ + VL due to the voltage drop due to the current carrying path passing through the resistor 20R ₁ and the collector and emitter of the second transistor 20T ₂ . They have a similar relationship. Therefore, at this time, both the first and second transistors 20T ₁ and 20T ₂ remain on, and the first and second light emitting diodes 18B ₁ and 18
_B2 both remain off. This indicates that the forward voltage drop VL of the first and second light emitting diodes 18B ₁ and 18B ₂ is utilized as the hysteresis voltage width.

Next, when the main circuit voltage becomes completely lower than the voltage value corresponding to VTL in Fig. 4 (weak 200 [V]), as explained at the beginning, the input voltage to the voltage detection circuit becomes Exceeds VL and VB+
The relationship is lower than that of VZ. Therefore, at this time, the first and second transistors 20T ₁ and 20T ₂
are both off, the first and second light emitting diodes 18B ₁ and 18B ₂ are both on, and the resistors 20R ₁ ,
A conduction path passing through the first and second light emitting diodes 18B ₁ and 18B ₂ is formed. 100~ as mentioned above
When the voltage drops from 200 [V] to VTL (VTL = VTH - VH), the first and second light emitting diodes 18
B ₁ and 18B ₂ are turned on, thereby turning on the first and second optically triggered thyristors 18A ₁ and 18A ₂ , and the winding start tap 17B of the secondary winding 17B is connected to the output terminals P ₁ and N ₁ . A DC power source with a voltage E ₂ corresponding to the secondary voltage induced between the winding end tap 17B _e and the winding end tap _17B e is output.

As mentioned above, when the main circuit voltage is low, the output terminal
P ₁ and N ₁ are the winding start taps 17 of the secondary winding 17B.
2 induced between B _s and the winding end tap 17B _e
A DC power supply with a voltage E ₂ corresponding to the next voltage is output,
When the main circuit voltage is high, the DC voltage E ₃ corresponding to the secondary voltage induced between the intermediate tap 17B _t and the end tap 17B _s of the secondary winding 17B is applied to the output terminals P ₁ and N _1. Power is output. In this case the voltage
E ₂ and voltage E ₃ can be set as E ₂ = E ₃ by appropriately setting the number of turns between the taps of the secondary winding 17B. Since the tap _of the secondary winding _17B of is supplied with quasi-constant voltage DC power.

In addition, the voltage waveform at both ends of the capacitor 6 (output ends P ₁ , N ₁ ) is determined by the loads connected in parallel (in this embodiment, the voltage detection circuit, tripping coil 8, thyristor 9, resistor 12, and control circuit 11). The lower the resistance value of the load, the larger the ripple. Therefore, even if a current containing ripples is input to the voltage detection circuit, since this voltage detection circuit has hysteresis characteristics, the first and second light emitting diodes 18B ₁ , 1 which are light emitting elements
The light emission of 8B ₂ is not affected by ripples,
The first and second photo-triggered thyristors 18A ₁ and 18A ₂ , which are light receiving elements, are normally turned on and turned off. In the above state, when a leakage fault occurs in the load 4 and a leakage current flows through the main circuit conductor 3, a detection current flows through the secondary side of the zero-phase current transformer 10.

If this detected current exceeds a predetermined value, the control circuit 11 determines that there is an earth leakage accident, and the signal output terminal S
outputs a trigger signal to turn on the thyristor 9. The tripping coil 8 is then energized, the main circuit contact 2 is opened, and the tripping is completed.

On the other hand, when the push button switch 13 of the operation test section is closed, a part of the main circuit current is passed through the resistor 14 to the primary side of the zero-phase current transformer 10 as a simulated earth leakage current. As a result, a detection current flows through the secondary side of the zero-phase current transformer 10. Due to this detected current, the main circuit contact 2 is opened as in the case of the actual earth leakage accident described above. It is confirmed that the earth leakage breaker's earth leakage accident response function works normally.

In addition, in this earth leakage breaker, a thermal relay (not shown) operates to open the main circuit contact 2 in the event of an overcurrent accident, and an electromagnet (not shown) operates to open the main circuit contact 2 in the event of an instantaneous operation such as a short circuit. Open circuit contact 2.

As described above, in this embodiment, the main circuit voltage is detected based on the voltages at the output terminals P ₁ and N ₁ of the first and second rectifying sections, and this detects the voltage of the secondary winding 17B of the transformer 17. Since the taps are automatically switched, the output terminal
A quasi-constant voltage DC power supply that is unrelated to the main circuit voltage can be output to P ₁ and N ₁ and can be shared by 100 to 200 [V] and 200 to 415 [V] power supply systems.

Furthermore, even when the main circuit voltage changes from low voltage to high voltage to low voltage to high voltage, the voltage detection circuit has hysteresis characteristics, so the first and second light-triggered thyristors 18A ₁ and 18A ₂ are connected to the main circuit. It does not turn on or turn off in response to slight fluctuations in voltage, and uniform DC power is output from the output terminals P ₁ and N ₁ .

Further, the secondary voltage induced in the secondary winding 17B of the transformer 17 is transmitted through the first to fourth diodes 19D ₁
Since the rectification is performed by the first to fourth diodes 19D _{1 to 19D 4} and the first and second light-triggered thyristors 18A ₁ and 18A ₂ , the first to fourth diodes 19D ₁ to 19D ₄ and the first and second light The trigger type thyristors 18A ₁ and 18A ₂ may have approximately the same current capacity.

Furthermore, even if the main circuit voltage is high or low, quasi-constant voltage DC power is output from the output terminals P ₁ and N ₁ , so the capacitor 6 only needs to have a low withstand voltage, and the trip coil 8 and thyristor 9. The resistor 12 may have a small capacity, the control circuit 11 will operate normally, and the function of the earth leakage response section will be highly reliable.

Next, second to twentieth embodiments of the present invention will be described with reference to FIGS. 5 to 23. In FIGS. 5 to 23, the same parts as those in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted, and only the different parts will be explained.

The second embodiment shown in FIG. 5 has a diode between the first embodiment shown in FIG. 3 and the first and second light emitting diodes 18B ₁ and 18B ₂ of the voltage detection circuit and the output terminal N ₁ . The difference is that 22D are connected in series in the forward direction.

With the above configuration, if the forward voltage drop of the diode 22D is VD, the hysteresis voltage VH of the voltage detection circuit is VL + VD (VL is the forward voltage drop of the first and second light emitting diodes 18B ₁ and 18B ₂ ). ). As a result, when the main circuit voltage changes from high voltage to low voltage, the tap of the secondary winding 17B will not switch unless the main circuit voltage decreases by the forward voltage drop VD compared to the first embodiment. Sudden changes in the DC power output from the output terminals P ₁ and N ₁ can be prevented. Other functions and effects are the same as those in the first embodiment, so explanations will be omitted.

Next, a third embodiment will be described with reference to FIG. In the third embodiment, the diode 22D in the second embodiment is removed and a constant voltage diode 22 is used.
Z is connected in the opposite direction.

With the above configuration, the hysteresis voltage VH of the voltage detection circuit becomes VL + VZ (VZ is the Zener voltage of the voltage regulator diode 22Z), and the second
The same effects as in the embodiment can be obtained.

Further, if a diode is connected in the forward direction between the cathode of the constant voltage diode 22Z and the output terminal _N1 , the hysteresis voltage VH can be increased to VL+VZ+VD. The other effects are the same as those of the first embodiment, so their explanation will be omitted.

Next, a fourth embodiment will be described with reference to FIG. The fourth embodiment includes the first and second light-triggered thyristors 18A ₁ ,
Diode 23D ₁ to prevent reverse voltage application to 18A ₂ ,
23D ₂ are inserted in series.

With the above configuration, even if a large reverse voltage is applied to the first and second optical trigger thyristors 18A ₁ and 18A ₂ while an optical trigger signal is input, the diodes 23D ₁ and 23D ₂ It also becomes possible to share the reverse voltage and reduce the reverse leakage current. Therefore, the first and second light-triggered thyristors 1
Since the loss of 8A ₁ and 18A ₂ is small, there is no problem even if it is used in a power supply system with a large reverse voltage. Other functions and effects are the same as those in the first embodiment, so explanations will be omitted.

Next, a fifth embodiment will be described with reference to FIG. The fifth embodiment is different from the winding start tap 17B _s of the secondary winding 17B of the transformer 17 in the first embodiment.
The anode of the diode _24D1 is connected to the diode 24D1, and its cathode is commonly connected to one end of the capacitor 6 and the input terminal _P3 of the voltage detection circuit. Also, the output terminal P ₁ ,
A smoothing capacitor 24C is connected between _N1 .

With the above configuration, only the DC power source that has half-wave rectified the secondary voltage induced between the winding start tap 17B _s and the winding end tap 17B _e of the secondary winding 17B of the transformer 17 can detect the voltage. Supplied to the circuit.
The voltage detection circuit that detects the voltage of the main circuit detects the voltage of the intermediate tap 17B _t when the optical thyristors 18A ₁ and 18A ₂ are turned on,
Since the voltage between _7Bs and the intermediate tap _17Bt is also applied, a secondary voltage proportional to the primary voltage of the main circuit cannot be obtained. Therefore, tap 1 at the beginning of winding has the highest voltage.
Detect the voltage between 7B _s and winding end tap 17B _e .
Other effects are the same as those of the first embodiment, so explanations will be omitted.

Next, a sixth embodiment will be explained with reference to FIG. The sixth embodiment includes the first and second light-triggered thyristors 18A ₁ ,
Diode 25D ₁ to prevent reverse voltage application to 18A ₂ ,
25D ₂ are inserted in series.

With the above configuration, even if a reverse voltage is applied to the power supply system, it can be absorbed by the diodes 25D ₁ and 25D ₂ , as in the fourth embodiment, so that the first and second light Trigger type thyristor 17B ₁ ,
The loss of 17B ₂ becomes smaller. Other effects are the same as those of the fifth embodiment, so explanations will be omitted.

Next, a seventh embodiment will be described with reference to FIG. In the seventh embodiment, the DC power detected by the voltage detection circuit is connected to the winding start tap 1 of the secondary winding 17B.
7B _s and output terminal N ₁ , resistor 26R, diode 24
A series circuit with D ₁ and resistor 26R ₂ is connected. The cathode of the diode 24D ₁ is connected to the emitter of the first transistor 20T ₁ of the voltage detection circuit, one end of the first resistor, and one end of the capacitor 6. Start of roll tap 17B _s and end of roll tap 17B _e
The voltage between is divided by resistors 26R ₁ and 26R ₂ ,
This divided voltage is half-wave rectified by the diode _24D1 and applied to the voltage detection circuit. Therefore, since the voltage applied to the voltage detection circuit becomes low, there is an advantage that the parts constituting the voltage detection circuit only need to have a low breakdown voltage. In addition to this, this embodiment provides the same effects as the sixth embodiment.

Next, an eighth embodiment will be described with reference to FIG. 11. The eighth embodiment differs from the seventh embodiment in that the first and second light-triggered thyristors 18A ₁ , 18
Diode 2 is connected to prevent reverse voltage from being applied to A ₂ .
This is a configuration in which 7D ₁ and 27D ₂ are connected.

In the eighth embodiment configured in this way, even if a reverse voltage is applied to the first and second photo-triggered thyristors 18A ₁ and 18A ₂ , the diodes 27D ₁ and 27
Since the reverse voltage can be absorbed by D ₂ , the first and second light-triggered thyristors 17B ₁ , 17
B ₂ losses will be smaller. The other effects are the same as those in the fourth to sixth embodiments, so their explanations will be omitted.

Next, a ninth embodiment will be described with reference to FIG. 12. In the ninth embodiment, the photocoupler 18
The first and second light-triggered thyristors 18A ₁ and 18A ₂ , which are light-receiving elements of the
_Bs , and the other end is connected to the anode of the first diode 28D _{1 and the cathode of the second diode 28D 2 of} a rectifier circuit consisting of the first to sixth diodes 28D ₁ to 28D ₆ . Further, the intermediate tap _18Bt of the secondary winding 17B is connected to the anode of the third diode 28D ₃ and the cathode of the fourth diode 28D ₄ of the rectifier circuit.
Furthermore, the winding end tap 18B _e of the secondary winding 17B is
It is connected to the anode of the fifth diode 28D ₆ and the cathode of the sixth diode 28D ₆ .
and the first, third, and fifth diodes 28D ₁ ,
The cathodes of 28D ₃ and 28D ₅ are commonly connected and form the output terminal P ₁ of the rectifier circuit. Also, the second, fourth,
The anodes of the sixth diodes 28D ₂ , 28D ₄ , and 28D ₆ are commonly connected to form the output terminal N ₁ of the rectifier circuit. In the above, the first and second photo-triggered thyristors 18A ₁ and 18A ₂ and the first and second diodes 28D ₁ and 28D ₂ constitute a first rectifier, and the third to sixth diodes 28D ₃ to 2
_8D6 constitutes a second rectifying section.

Note that the first and second light-triggered thyristors 18
A _first gate circuit consisting of a resistor 21R _{1 and a capacitor 21C 1 and} a resistor ₂ are connected between the gates of A 1 and 18A 2 and the cathode.
1R ₂ and a second gate circuit consisting of a capacitor 21C ₂ are connected to each other.

In the ninth embodiment configured as described above, the functions of the first and second light-triggered thyristors 18A ₁ and 18A ₂ in the first embodiment are the same as those of the first and second light-triggered thyristors 18A. ₁ , 18A ₂ and 1st,
The second diodes 28D ₁ and 28D ₂ are used instead, and the operation is the same as in the first embodiment, so the explanation will be omitted. Note that the first and second light-triggered thyristors 18A ₁ , 18 in the turn-on state
Since the reverse voltage applied to _A2 is only a forward voltage drop, the loss due to the application of the reverse voltage is extremely small.Other functions and effects are the same as those of the first embodiment, so a description thereof will be omitted.

Next, a tenth embodiment will be described with reference to FIG. 13. In the tenth embodiment, the fifth embodiment in the ninth embodiment
The configuration is such that the sixth diodes 28D ₅ and 28D ₆ are removed, and the first and second constant voltage diodes 29Z ₁ and 29Z ₂ are connected.

In the tenth embodiment configured as described above, it is possible to absorb surge voltage by the first and second constant voltage diodes 29Z ₁ and 29Z ₂ , thereby increasing reliability. Other functions and effects are the same as those of the ninth embodiment, so their explanations will be omitted.

Next, an eleventh embodiment will be described with reference to FIG. 14. In the eleventh embodiment, in the ninth embodiment, the winding start tap 17 of the secondary winding 17B of the transformer 17 is
The anode of the diode _30D1 is connected to _Bs , and the cathode is connected to the input terminal _P3 of the voltage detection circuit.

In the eleventh embodiment configured as described above, the voltage detection of the main circuit in the voltage detection circuit is performed between the winding start tap 17B _s and the winding end tap 17B _e of the secondary winding 17B of the transformer 17. Since the induced secondary voltage is detected only from a rectified DC power source, the number of components constituting the voltage detection circuit is small, which is economical. Other functions and effects are the same as those of the ninth embodiment, so their explanations will be omitted.

Next, a twelfth embodiment will be described with reference to FIG. 15. In the twelfth embodiment, as in the seventh embodiment, the voltage between the winding start tap 17B _s and _N1 is connected to the resistors _26R1 and 26R1.
The voltage is divided by 6R ₂ and connected to the input terminal P ₃ of the voltage detection circuit via a diode 24D ₁ to apply a half-wave rectified voltage. A capacitor 31C is connected in parallel to the output terminals P ₁ and N ₁ .

In the twelfth embodiment configured as above, the eleventh
As in the embodiment described above, the voltage detection circuit includes only a DC power source that rectifies the secondary voltage induced between the winding start tap 17B _s and the winding end tap 17B _e of the secondary winding 17B of the transformer 17. Since the voltage is supplied under pressure, the voltage detection level only needs to be low, and the rating of the components forming the voltage detection circuit can be low, making it economical.
Other functions and effects are the same as those of the ninth embodiment, so their explanations will be omitted.

Next, a thirteenth embodiment will be explained with reference to FIG. 16. The thirteenth embodiment removes the first and second diodes 28D ₁ and 28D ₂ in the twelfth embodiment,
This is a configuration in which first and second constant voltage diodes 32Z ₁ and 32Z ₂ are connected in the forward direction.

In the thirteenth embodiment configured as described above, the surge voltage is transferred to the first and second constant voltage diodes 32Z ₁ ,
Since it can be absorbed by 32Z ₂ , reliability is increased. Other effects are the same as those of the twelfth embodiment, so explanations will be omitted.

Next, a fourteenth embodiment will be described with reference to FIG. 17. In the fourteenth embodiment, the first and second light-triggered thyristors 18A ₁ and 18 in the ninth embodiment
A switching circuit consisting of A ₂ and the first and second gate circuits is connected to the first to fourth diodes 33
A switching circuit consisting of D ₁ to 33D ₄ and a phototransistor 34A is used, and the first and second light emitting diodes 18B ₁ and 18B ₂ are replaced with a light emitting diode 34B. The light emitting diode 34B serves as a light emitting element, the phototransistor 34A serves as a light receiving element, and these are configured as a photocoupler 34. In the above, the first to fourth diodes 33D ₁ to 33D ₄ , the phototransistor 34A, and the first and second diodes 28D ₁ and 28D ₂ constitute a first rectifier,
The third to sixth diodes 28D ₃ to 28D ₆ constitute a second rectifier. In the fourteenth embodiment, the light emitting diode 34B is turned on and the phototransistor 34A is turned on.
The secondary voltage induced in the secondary winding 17B is transmitted to the first to sixth diodes 28D 1 to ₃₈ via a switching circuit consisting of first to fourth diodes 33D ₁ to 33D ₄ and a phototransistor 34A.
It is rectified by a rectifier circuit consisting of D ₆ and the output terminal P ₁ , N ₁
is output to.

The fourteenth embodiment differs from the ninth embodiment only in the configuration of the switching circuit, and the other operations and effects are the same, so a description thereof will be omitted.

Next, a fifteenth embodiment will be described with reference to FIG. 18. In the 15th embodiment, the winding start tap 17B _s and N ₁
The voltage between them is divided by resistors 26R ₁ and 26R ₂ , half-wave rectified through diode 24D ₁ , and applied to the voltage detection circuit. Furthermore, the first in the fourteenth embodiment,
The second diodes 28D ₁ and 28D ₂ are connected to the first and second diodes.
They are replaced with constant voltage diodes 36Z ₁ and 36Z ₂ .

According to the 15th embodiment configured as above,
The voltage detection circuit includes a secondary winding 17B of the transformer 17.
Only the voltage-divided DC power source obtained by rectifying the secondary voltage induced between the winding start tap _17Bs and the winding end tap _17Be is supplied. Therefore, the voltage detection circuit can detect voltage at a low level,
It is economical because the component ratings are low. Furthermore, surge voltage can be absorbed by the first and second constant voltage diodes 36D ₁ and 36D ₂ . The other effects are the same as those of the fourteenth embodiment, so their explanation will be omitted.

Next, a sixteenth embodiment will be described with reference to FIG. 19. In the sixteenth embodiment, the secondary winding 1 of the transformer 17
The collector of the first phototransistor _37A1 and the emitter of the second phototransistor _37A2 are connected to the winding start tap _17Bs of 7B.
The emitter of the first phototransistor _37A1 is connected in the forward direction to the output terminal _P1 via the first diode _38D1 . Further, the collector of the second phototransistor 37A ₂ is connected in the forward direction to the output terminal N ₁ via the second diode 38D ₂ . Further, the first and second phototransistors 37A ₁ and 37A ₂ as light receiving elements are connected to the first and second light emitting diodes 37B 1 and _37B in the voltage detection circuit.
37B ₂ is incorporated, these are photocoupler 37
It is configured as. In the above, the first and second
phototransistors 37A ₁ , 37A ₂ and a first phototransistor,
The second diodes 38D ₁ and 38D ₂ constitute a first rectifier, and the third to sixth diodes 28D ₃
28D6 to _28D6 constitute a second rectifying section.

In this 16th embodiment, no reverse voltage is applied to the first and second phototransistors 37A ₁ and 37A ₂ due to the first and second diodes 38D ₁ and 38D ₂ , so that a good switching operation is performed. . Also, this 16th embodiment differs from the 9th embodiment only in the configuration of the switching circuit, and the other configurations, operations, and effects are the same as those of the 9th embodiment, so a description thereof will be omitted. .

Next, a seventeenth embodiment will be described with reference to FIG. 20. The seventeenth embodiment differs from the first embodiment in the configuration of the voltage conversion section. That is, the first, second, and third impedance elements are connected between the lines of the main circuit conductor 3.
A series circuit consisting of resistors 39R ₁ , 39R ₂ , and 39R ₃ is connected. and the first and second resistors 39R ₁ ,
The connection point of _39R2 is connected to the anode of the first light-triggered thyristor _18A1 and the cathode of the second light-triggered thyristor _18A2 . Also, connect the connection point of the second and third resistors 39R ₁ and 39R ₂ to the first
It is connected to the anode of the diode 19D ₁ and the cathode of the second diode 19D ₂ . Note that the anode of the third diode 19D ₃ and the cathode of the fourth diode 19D ₄ are connected to the third resistor 39.
It is connected to one conductor of the main circuit conductor 3 together with R ₃ .

According to the seventeenth embodiment configured as described above, the main circuit voltage is divided by the resistance as an impedance element, and the divided voltage is applied to the first and second
The voltage can be applied to the optically triggered thyristors 18A ₁ , 18A ₂ and the first to fourth diodes 19D ₁ to 19D ₄ . In this case, the voltage applied in the voltage converter can be applied at a low value, and low voltage rated components can be used. Power losses can be reduced. The other effects are the same as those in the first embodiment, so their explanation will be omitted.

Next, an 18th embodiment will be described with reference to FIG. 21. In the 18th embodiment, the first to third resistors 39, which are the impedance elements in the 17th embodiment,
R ₁ to 39R ₃ are connected to the first to third capacitors 4
Replaced with 0C ₁ to 40C ₃ . According to the 18th embodiment configured in this way, the main circuit voltage is
Since capacitor voltage division is performed by the third capacitors 40C ₁ to 40C ₃ , power loss in the voltage converter can be further reduced. In addition, the rated voltage of the parts used is low, which improves economic efficiency. Other effects are the same as those in the first embodiment, so explanations will be omitted.

Next, a nineteenth embodiment will be described with reference to FIG. 22. The 19th embodiment is the first embodiment in the 17th embodiment.
The configuration is such that the resistor _39R1 is removed.

According to the nineteenth embodiment configured as above,
The main circuit voltage is connected to the second and third resistors 39R ₂ and 39R ₃
The divided voltage can be applied to the rectifier circuit, and the power loss is further reduced by ₁ of the first resistor 39R.

Next, a 20th embodiment will be described with reference to FIG. 23. The 20th embodiment has a configuration in which the first capacitor _40C1 in the 18th embodiment is removed.

According to the 20th embodiment configured as described above, the main circuit voltage is connected to the second and third capacitors 40C ₂ ,
The voltage can be divided by 40C ₃ and this divided voltage can be applied to the rectifier circuit, and the first capacitor 40
C Power loss can be further reduced by ₁ minute.

The present invention is not limited to the above embodiments, and the voltage converter may have any configuration as long as it has the function of increasing or decreasing the main circuit voltage.

Further, the rectifier circuit in the power supply section may have any configuration as long as it has the function of combining and rectifying a plurality of voltages output from the voltage conversion section.

Furthermore, the voltage detection circuit in the power supply section detects the main circuit voltage based on the output voltage of the rectifier circuit,
Any structure may be used as long as it has the function of combining the voltages supplied to the rectifier circuit based on the detected signals.

In addition to this, the present invention can be modified and implemented in various ways without changing the gist of the invention.

〔Effect of the invention〕

As described above, according to the present invention, the voltage converter outputs the voltage of the main circuit as a plurality of different voltages, and some of the output voltages of the voltage converter are input to the switchable first rectifier circuit. However, the remaining output voltage is input to the second rectifier, and the voltage output from the rectifier circuit consisting of the first and second rectifiers is detected by the voltage detection circuit, and when this detected voltage value exceeds a predetermined value, If the voltage exceeds the predetermined value, the first rectifier is switched off, and the voltage detection circuit has a hysteresis characteristic to detect the predetermined value, so it can be used in both high and low voltage power supply systems. Furthermore, it is possible to provide an earth leakage breaker that exhibits highly reliable operating characteristics.

[Brief explanation of drawings]

1 and 2 are circuit configuration diagrams showing a conventional earth leakage breaker, FIG. 3 is a circuit configuration diagram showing a first embodiment of the earth leakage breaker according to the present invention, and FIG. 4 is a circuit diagram showing the first embodiment of the earth leakage breaker according to the present invention. Characteristic diagram for explaining the action of the example, 5th
23 are circuit configuration diagrams showing second to twentieth embodiments of the present invention. 1... Power source, 2... Main circuit contact, 3... Main circuit conductor, 4... Load, 6... Capacitor, 8... Tripping coil, 9... Thyristor, 10... Zero-phase current transformer, 11...Control circuit, 12...Resistor, 13...
...Push button switch, 14...Resistor, 15...Surge absorption element, 17...Transformer, 18...Photocoupler, 18A ₁ , 18A ₂ ...First and second optically triggered thyristors, 18B ₁ , 18B ₂ ...first, second
Light emitting diodes, 19D ₁ to 19D ₄ ... 1st
to fourth diode, 20T ₁ , 20T ₂ ...first and second transistors, 20R ₁ , 20R ₂ , 2
0R ₃ ...First, second, third resistance, 20Z...
Constant voltage diode, 21R ₁ , 21R ₂ ...Resistance,
21C ₁ , 21C ₂ ... Capacitor, 22D ... Diode, 22Z ... Constant voltage diode, 23
D ₁ , 23D ₂ ...first and second diodes, 24
D ₁ ...First diode, 24C... Capacitor, 25D ₁ , 25D ₂ ... First and second diodes, 26R ₁ , 26R ₂ ... Resistor, 27D ₁ , 27D ₂
...First and second diodes, 28D ₁ to 28
D ₆ ...first to sixth diodes, 29Z ₁ , 2
9Z ₂ ...first and second constant voltage diodes, 20
D ₁ ...First diode, 31C...Capacitor, _32Z1 , _32Z2 ...First and second constant voltage diodes, _33D1 to _33D4 ...First to fourth diodes, 34...Photocoupler , 34A...
Phototransistor, 34B...Light emitting diode, 35C...Capacitor, 36Z ₁ , 36Z ₂ ...
1st and 2nd constant voltage diodes, 37... Photocoupler, 37A ₁ , _{37A 2} . . . First and second phototransistors, 37B ₁ , 37B ₂ . 38D ₂ ...1st,
Second diode, 39R ₁ , 39R ₂ , 39R ₃ ...
...first, second, and third resistances, 40C ₁ , 40C ₂ ,
40C ₃ ...first, second, and third capacitors.

Claims (1)

[Scope of Claims] 1. A main circuit conductor portion having main circuit contacts and connecting a power source to one end and a load to the other end to form a main circuit; When it is detected that an earth leakage fault has occurred on the load side, the main circuit is an earth leakage accident response unit that opens circuit contacts; a first rectifier unit that uses a switching element to which a part of the output voltage converted by the voltage conversion unit is input; a rectifier circuit comprising a second rectifier to which the output voltage converted by the voltage converter other than the output voltage input to the rectifier is input, and a voltage output from the rectifier circuit that exceeds a predetermined value; It detects whether or not the voltage exceeds the specified value, and switches off the switching element when the voltage exceeds the predetermined value. An earth leakage breaker comprising: a voltage detection circuit having a hysteresis characteristic in which the detection level differs depending on when a predetermined value is reached;