JPS6013419A - Circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention is directed to the improvement of an H1 type circuit breaker which opens main circuit contacts in response to a current fault.

[Technical background of the invention]

An example of the circuit configuration of a conventional circuit breaker is shown in Figure 1.

In Fig. 21, power is supplied from a power source 3 to a load 4 through a main circuit conductor 2 provided with a main circuit contact 1. The current flowing through the main circuit conductor 20, that is, the main circuit current, is detected by the primary and secondary sides of the current transformer 5 with the main circuit conductor 2 as the primary side, and this detection signal is rectified by a full-wave rectifier 6 consisting of a diode. After that, the voltage is applied to a series circuit consisting of a constant voltage diode 8 and a variable resistor 9 via a resistor 7, and is converted into a voltage signal. The voltage is applied to the signal input terminal C of the control circuit 10 as a main circuit current detection signal. When the main circuit current becomes abnormally large due to an overcurrent accident, the control circuit 10 detects an overcurrent release because the detection signal applied to the signal input terminal C exceeds a preset value. The thyristor 1 is connected between the output terminals of the full-wave rectifier 6 via the resistor 7.
A gate signal is supplied from the signal output terminal S to the thyristor 1 of the series circuit (tripping drive circuit) consisting of the thyristor 1 and the tripping coil 12 to turn it on and excite the tripping coil 12. The main circuit contact 1 is opened. Further, a capacitor 13 is connected between the output terminals of the full-wave rectifier circuit 6 via a resistor 7, and the rectified detection signal is completely smoothed. Furthermore, the voltage between the anode and cathode of the constant voltage diode 8 becomes a constant voltage, and this constant voltage is supplied to the power supply terminals P and H of the open side 1 circuit 10. Note that 14 is a surge absorber connected between the output terminals of the full-wave rectifier 6, which suppresses overvoltage generated on the secondary side of the current transformer 5 when the main circuit current becomes large due to a short circuit accident, etc. do.

[Problems with background technology]

In the circuit breaker as described above, the current transformer 5 has a number of windings on the secondary side when the rated main circuit current on the primary side is 300OA and the rated detection signal current on the secondary side is 50mA. 60,000 times will be adopted. Also, in the above ratings, the proportional relationship between the secondary side and the primary 11111, i.e.
Detection signal flow. -6- is detected in proportion to the main circuit current by 10 to J6 times. However, since the current transformer 5 as described above has a large number of turns according to the quadratic first law, the resistance value of the secondary winding increases to several Ω, and the power consumed by the current transformer 5 itself increases. As a result, the detection signal current is only 4 to 5 times proportional to the main circuit current, resulting in poor overcurrent detection characteristics.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object thereof is to provide a circuit breaker with an expanded main circuit current detection range and an improved overcurrent detection function.

[Summary of the invention]

In order to achieve the above object, the first, second, and third inventions are characterized by the following configurations. That is, the first
In the invention, when the main circuit current is in a large current region, the main circuit current is detected by a Hall element biased by an AC constant voltage or an AC constant current, and when the main circuit current is in a small current region, the main circuit current is detected by the secondary output of the current transformer. i'i41 outputs 4ω main circuit current
．． '+'7. , in the second invention, 1 main circuit 11
1; When the current is in the dog current region, the main +i+
When the main circuit current is small, the main circuit current is detected by a second Hall element which is biased in the same way as the first Hall element and has a high detection sensitivity. In the third invention, the main circuit h'a current is detected by the first Hall element biased by 6 DC constant current pressure or DC constant current in a large current region, and the main circuit current is small. In the current region, the main circuit current is detected by a second Hall element biased by an AC constant voltage or an AC constant current.

[Embodiments of the invention]

Examples of the present invention will be explained below with reference to the drawings. Second
This is a circuit diagram showing the first embodiment of the present invention, in which the same parts as pp; i =+ are given the same symbols □.

In FIG. 2, a power source 3 is connected to one end of a main circuit conductor 2 provided with a main circuit contact 1, and a load 4 is connected to the other end, forming a main circuit. The main circuit has the main circuit conductor 2 as a primary side, and a control 1' circuit 1 for supplying a municipal power.
A current transformer having a secondary winding Z5A, a second secondary winding 15B1 for main circuit current detection, and a third secondary winding 15C for supplying bias power to a Hall element to be described later. 15 are provided. The trenched main circuit conductor 2 is provided with a Hall element 16 having bias terminals M, N and an output terminal R1S.

An input end of a full-wave rectifier 6 consisting of a diode is connected between the terminals of the first secondary winding 15A of the current transformer 15, and a capacitor 13 is connected to the output end. One end of this capacitor 13 is connected to one end of a tripping drive circuit including a thyristor 11 and a tripping coil 12, and one end of a resistor 7. Further, the cathode of a constant voltage diode 80 is connected to the other end of the resistor 7, and the anode is connected to the other end of the capacitor 13.

The cathode of the constant voltage diode 8 constitutes the control tube 1 temperature output terminal P, the anode of the constant voltage diode 8 constitutes the control market output terminal N, and the control power supply output terminal P, N1. are the peak value selection circuits 1 whose details will be described later.
7. Electric power of the amplifier circuit 18 and control circuit 10, 4 P
+H and supplies control power. Current transformer 1
The input terminal of a full-wave rectifier 19 consisting of a diode is connected between the terminals of the second second-order one-law winding 15B of the output resistor 21, and the sliding end C of the output resistor 21 is connected to the first terminal of the peak value selection circuit 17. is connected to the signal input terminal D1 of.

A resistor 22 is connected between the terminals of the third secondary winding 15C of the current transformer 15. Further, one end of this third secondary side winding net 15C is connected to one end of an AC constant current circuit 25 consisting of constant current diodes 23A, 23B and resistors 24A, 24B, and the third secondary side winding net 15C The side end of is connected to the bias terminal N of the Hall element 16. Furthermore, the other end of the AC constant current circuit 25 is connected to the bias terminal IV4 of the Hall element 16. - In the case 14, the constant current diodes 20A and 20B are equivalent to short-circuiting between the gate and source of a field effect transistor. The AC constant current circuit 25 is configured by connecting a constant current diode 20fi with a resistor 27A connected in parallel and a constant current diode 19B with a resistor 20B connected in parallel in reverse polarity. The signal output terminal tv(IN) of the twisted Hall element 16 is connected to the signal input terminal D1' and the terminal N of the amplifier circuit 18. The signal input terminals D2i/j are disconnected.This peak value selection circuit 17 compares the input signals input to the first and second signal input terminals, D2, respectively, and selects the input signal with the higher peak value. Select a signal and output it to the output terminal S.The output terminal S of the selection circuit 17 is connected to the signal input terminal DK of the control circuit 10.
The output terminal S of is connected to the gate of thyristor II in the trip drive circuit. The above tripping tllK l! 1
In the 1OJ path, when the thyristor 1 is turned on, the tripping coil 12f is excited, the tripping mechanism (not shown) is fully driven, and the catch of the main circuit contact I is released 7 to open it.

In the above-described filter selection circuit 17, the signal levels Lj are set to the first and second input numbers DI ID2 as follows. That is, in a region where the main circuit hood current is small, for example, 1000 A or less, the current transformer 15
The second quadratic +lIl, +φ obtained by Volume 1 Gen15B
The signal level of the output signal is set to be higher than the 1 level of the Kakide Satoru number obtained by the Hall element I6. In a region where the main circuit current is large, for example, 100OA or more, the second secondary winding 15B detects (11)
The (r5-V-F level of No. 1) is set so as to be smaller than the signal level of the detection signal obtained by the Hall element 16. Regarding the detection signal of the secondary winding g!
This is done by changing the h'jl 11-'11 ratio of 8.

Next, the book 1-ji, which is structured as in -F, ]7i1
The l'1 masterpiece of example i will be described. Power id of power supply I
, are supplied to the load 4 via the main circuit conductor 2. 1st, 2nd and 3rd winding Z5A of current transformer 15.

15B and 15C have 2? according to the main circuit current. Current is output at ′. Current transformation: k I 5 first quadratic 4141
The secondary flow of the first volume of paddy Z5A is rectified by the full-wave diverter 6,
After being smoothed by capacitor Z3, it is supplied to the tripping drive circuit of thyristor II and tripping coil 12. Further, the output of the capacitor 13 is regulated to 17 voltage by the constant voltage diode 8, and the output of this constant voltage is supplied to the control circuit IO.
One wave height, one direct event interpretation circuit I7 and the amplifier circuit 18 are controlled with a constant voltage of 111 widths.

It is empowered as a source.

On the other hand, the main circuit 'r' flow detection secondary' current which is output to the 20th and 202nd order middle water expansion I5B of the current transformer Z5 is rectified by the full-wave rectifier circuit I9, and is rectified by the variable resistor 2I. city,
The output signal is changed to an output signal and inputted to the first input terminal D1 of the peak value selection circuit 17.

Further, the secondary current for bias supply of the Hall element I6 outputted to the third secondary winding 15C of the current transformer Z5 is converted into a voltage signal by the resistor 22, and is converted to a voltage signal by the AC γHr and constant current circuit 25. As shown in Figure 3, the bias terminals M and H of the Hall element I6 are used as an AC constant current bias power source for the Hiko current waveformer.
supplied to The output from the output terminals R and S of the Hall element Z6 biased with an AC constant current is proportional to the main circuit current in a direction perpendicular to the magnetic field generated by the bias current and the main circuit current, and Since the output is the product of the waveform of the main circuit current and the waveform in phase with this main circuit current, the full-wave rectified 3rd B)! The voltage waveform V shown in I is obtained. Among the output signals of the Hall element 16, the output signal outputted by biasing the AC constant current in a certain period is given to the signal input terminal of the amplifier circuit 18 as a main circuit current detection signal. In the amplifier circuit I8, the output signal from the Hall element 16 is amplified by a predetermined amplification factor, and then applied to the second signal input terminal D2 of the peak value selection circuit 17. The wave height A1 internal selection circuit 17 selects the first,
The peak values of the detection signals applied to the second signal input terminal D2 are compared, and a detection signal having a larger peak value is supplied to the signal input terminal of the control circuit 10. When the detection signal exceeds a preset value, the control circuit IO applies a gate signal to the gate of the thyristor 11, turns on the thyristor II, and excites the tripping coil 12f. When the tripping coil Z2 is activated, a tripping mechanism (not shown) is moved to release the catch and open the main circuit contact I.

According to the present embodiment described below, the effects listed below can be obtained. F411, ■In the area where the main circuit current is small, the detection signal obtained from the second secondary winding 7.5B of the current transformer 15 is used to detect the main circuit current. Since the detection signal obtained from the Hall element I6 is used in a large area, the linearity of the detection weight can be greatly improved.

■The output signal of the detection signal obtained from the Hall element I6 is 1, which is rectified as the detection signal of the main circuit current, so it is economical because there is no need to use a rectification circuit such as an operational amplifier to rectify minute signals. In addition, when using the above rectifier circuit, the peak value MIA for each positive and negative half wave is 4-.
This is extremely advantageous since complicated adjustments such as j adjustment and phase adjustment are not required.

■The Hall element I6 does not saturate even in a region where the main circuit current is quite large, so the second secondary winding 5 Z s
It is possible to reduce the detection range of the detection signal by B. As a result, the number of turns of the second secondary winding 15B can be reduced, and a small iron core can be used, which is economical. Moreover, it becomes compact.

■As the number of turns of the second secondary winding 4' 15B of the current transformer I5 described above becomes smaller and the iron core becomes smaller,
No overvoltage is generated on the load side of the second secondary winding rsB, and as a result, a variable resistor 21 with a small rating can be used.
No harm done. Furthermore, since no overvoltage occurs on the output side of the Hall element 16, the constant current commercial diodes 23A, 2
3B can be used with a smaller rating, and there is no problem with practical use due to overvoltage.

■First, second, and third secondary windings 15A of current transformer I5,
15B and 15C separately perform the supply of control power, detection of the main circuit current, and supply of bias power to the Hall element 16, so that the detection signal of the main circuit current due to fluctuations in the power supply 3 is The reliability of detection accuracy is greatly improved. Furthermore, since the Hall element I6 is biased by the output from the third secondary winding 15C of the current transformer 15, it is easily insulated from the output terminals R and S of the Hall element 16, preventing potential cross-contact. It is performed reliably and the reliability of detection accuracy is high.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 4, the third current transformer I5 in FIG.
The secondary winding 15C's secondary winding resistor 22 and AC constant current circuit 25 are removed, and the third secondary winding! Between the lines of 1i1150, an AC constant voltage circuit 27 consisting of a piezo diode 26 and 26B connected in series with opposite polarity is connected, and one output terminal of this AC constant voltage circuit 27 is connected to a variable resistor 28. The other output terminal of the AC constant voltage circuit 27 is connected to the bias terminal N of the Hall element 16. For other configurations,
Since it is the same as the first embodiment shown in the figure, the explanation will be omitted.

In a second embodiment of an upper rudder-like configuration, the Hall element 16
An AC constant voltage bias is applied to the output terminals R and S of the Hall element I6 to obtain detection signals as in the first embodiment. Further, since the AC voltage for biasing the Hall element I6 can be adjusted by the variable resistor 28, there is an advantage that the signal level of the detection signal can be changed more easily than changing the amplification factor of the amplifier circuit I8.

Other operations and effects are the same as those in the first embodiment, so their explanation will be omitted.

Next, a third embodiment will be described with reference to FIG.

In Figure 5, the full-wave rectifier 19, surge absorber 2θ, and variable resistor 2z connected to the secondary side of the second secondary winding Hr5B of current transformer I5 in Figure 2 are removed. Then, the resistor 29 is connected to the second secondary winding &! Connected between the terminals of ztyB. Further, constant current diodes 30A and 30B are connected in series with opposite polarities to one end of this resistor 29, and a resistor 31 and a resistor 31B are connected to the constant current diodes 30A and 30B, respectively.
One end of the AC constant current circuit 32 is connected in parallel with each other, and the other end of the resistor 29 is connected to the Hall element 71 shown in FIG.
5 (hereinafter this Hall element I6 will be referred to as a first Hall element I6) is connected to a bias terminal N of a second Hall element 33 which has a different detection sensitivity from that of the Hall element I6. The other end of the AC constant current circuit 32 is connected to the bias terminal V of the second Hall element 33.

In the above, the second Hall element 33 has a magnetic ring 33A made of ferromagnetic material attached thereto to increase detection sensitivity. The output terminals R and S of the second Hall element 33 are connected to the amplifier circuit 34.
It is connected to the signal input terminal and the power supply terminal N. Oh,
The power supply terminals P and N of this amplifier circuit 34 are connected to the control power supply output terminals P, N1 which are both ends of the constant voltage diode 8,
It has control lights. The signal output terminal 8 of the increase Ih circuit 34 is connected to the first signal input terminal of the peak value selection circuit 17.

In the third embodiment with the above configuration, the detection sensitivity of the second Hall element 33 provided with the magnetic ring 33k is improved.

Therefore, the detection signal obtained by the second Hall element 33 can perform current detection in a region where the main circuit current is small. The detection signal obtained by this second Hall element 33 is amplified by an amplifier circuit 34, and this amplified detection signal is sent to a first circuit which performs current detection in a large region of main circuit current by a peak value selection circuit Z7. The detection signal from the Hall element 16 of will be carried out. In this third embodiment, in the region where the main circuit current is small, the current of π is detected by the second Hall element 33, so the current transformer 15
Since the second secondary 1111 winding 25B bears only the AC constant current bias to the second Hall element 33, it is possible to reduce the burden on the current transformer Z5. Other operations and effects are the same as those in the first and second embodiments, so their explanations will be omitted.

Next, a fourth embodiment will be described with reference to FIG.

In FIG. 6, the second 2 of current transformer I5 in FIG.
In order to remove the resistor 29 and the AC constant current circuit 32 connected to the next winding 15B, and also remove the amplifier circuit 34, and drive the second Hall element 33 with a DC constant current bias,
Second secondary side volume,! ,i! The input end of the full wave rectifier 35 is connected between the terminals of 15B, and the output end is connected to the DC constant current circuit 3.
The output terminal P2+N2 of this DC constant current circuit 36 is connected to the bias terminals M and H of the first Hall element 16 which performs current detection in a region where the main circuit current is large. The output terminals R and S of the Hall element 16 of No. 1 are connected to the signal input terminal D1 and the source terminal N of a rectifier circuit 37 which is composed of an operational amplifier etc. and can be rectified in a logical manner, and the signal output terminal S of this rectifier circuit 37 is The first <= signal input terminal of the peak value selection circuit 17,
is connected to. In addition, the third secondary side winding shaft 1 of the current transformer 15
The output terminal of the 5C constant current circuit 25 is connected to the bias terminals IJ and H of the second Hall probe 33 which performs current detection in a region where the main circuit current is small.

In the fourth embodiment configured as described above, the output terminals R and S of the second Hall element 33, which has high detection sensitivity and is used for detection in a region where the main circuit current is small, output an alternating current according to the main circuit current. A detection current is obtained, which is rectified by the rectifier circuit 37 to obtain a DC detection signal, which is applied to the first signal input terminal DI of the peak value selection circuit 37. Then, the detection signal from the second Hall element 33 is compared with the detection signal obtained from the first Hall element 16 applied to the second signal input terminal, and the detection signal obtained from the first Hall element 16 given to the second signal input terminal is compared. The detection signal is selected and applied to the signal input terminal of the control circuit 10 to perform the same operation as in the first to third embodiments. The other one n+ operations are the same as those in the third embodiment, so their explanation will be omitted.

In this embodiment, considering the case where a small iron core is used to make the current transformer I5 compact and inexpensive, the output of the secondary 1H11 winding 15C of the current transformer 15 iA3 is calculated as follows. 1+! sum up This saturated region corresponds to the upper limit value in a region where the main circuit current to be detected by the second Hall element 33 is small. As described above, when the output from the third secondary winding 15C, that is, the bias current is partially saturated, the main circuit current and the bias current cannot be synchronized over the entire half-wave range, and each At the end of the half wave, the bias current is no longer in phase with the main circuit current. Therefore, in the section where the phases do not match, a negative waveform is generated from the output terminals R and S of the second Hall element 33 as shown in FIG. 71. When a Koma waveform occurs,
During the period when the half wave is generated, the output of the amplifier circuit 18 is at zero potential, and the detection signal of the main circuit current during this period (10 to 20 m5eC at commercial frequency 506Of-Tz) is generated by the first Hall element 16. The detection signal used, that is, rectified by the rectifier circuit 37, is output from the peak value selection circuit 17 and given to the control circuit 10. Therefore, in this embodiment, the current transformer I5 is
can use a small iron core, making it compact and economical.

The other effects are the same as those of the third embodiment, so their explanation will be omitted.

The present invention is not limited to the first to fourth embodiments described above. For example, in the third embodiment shown in FIG. 5, the first and second Hall elements 16° 33 are biased with an AC constant current. The operation and effect can be obtained. Further, in the fourth embodiment shown in No. 61-4, the first Hall element 16
is driven by a DC constant current bias, and the second Hall element 33 is driven by an AC constant current bias, but the first Hall element is driven by a DC constant voltage bias, and the second Hall element 33 is driven by an AC constant voltage bias. The same operation and effect can be obtained even when the motor is driven. In addition, the present invention can be implemented with various modifications without departing from the gist.

〔Effect of the invention〕

According to the present invention described above, the main circuit is constructed by combining a Hall element biased with an AC or DC constant current bias or a constant voltage bias with a current transformer according to a large current region or a small current region of the main circuit current. Since the circuit breaker is configured to detect current, it is possible to provide a circuit breaker that can significantly expand the detection range for detecting overcurrent in the main circuit.

[Brief explanation of drawings]

Figure 1 shows a circuit configuration 11 of an example of a conventional circuit breaker.
71, Fig. 2 is a circuit configuration diagram showing a first embodiment of the circuit breaker according to the present invention, and Fig. 3 shows the operation of the same embodiment.
Figures 4 to 6 are circuit configuration diagrams showing the second to fourth embodiments of the present invention, and Figure 7 is a waveform diagram to explain the operation of the fourth embodiment. It is a diagram. I... Main circuit contact, 2... Main circuit conductor, 3... Power supply, 4... Load, 6... Full wave rectifier, 7... Resistor, 8... Constant voltage diode, IO...control circuit, z
I...Thyristor, 12...Tripping coil, I3...
...Capacitor, 15...Current transformer, Z5A, 15B,
75C... No. 1 of the current transformer. Second. @3 secondary winding,
16... Hall element, I7... Peak value selection circuit, 1
8...Amplification circuit, I9...Full wave rectifier circuit, 20...
・Surge absorber, 21... Variable resistor, 22...
-Resistor, 23A, 23B, 30A, 30B... Constant current diode, 24, 24B, 31A, 31B... Resistor, 25.32... AC constant current circuit, 26A. 26B... Constant voltage diode, 27... AC constant voltage circuit, 28... Variable resistor, 29... Resistor, 33...
... Hall element, 34 ... Amplification circuit, 35 ... Full wave rectifier circuit, 36 ... DC constant current circuit, 37 ... Rectifier circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 -m- Figure 4 Figure 5 Figure 6 6 7PT 1 □ 15A] 37171°35 P p p 1 23A ?523B 24A 24B 3A 3 1 day wa 4

Claims (1)

[Claims] A main circuit conductor having +11 main circuit contacts and forming a main circuit by connecting a power supply and a load, and an AC drive that is supplied with power from this main circuit conductor and outputs an AC constant current or AC constant voltage. circuit and
Detection according to the current flowing through the main circuit by being biased by an AC constant current or AC constant voltage outputted from the AC drive circuit, which is provided near the main circuit conductor in order to respond to the magnetic field caused by the current flowing through the main circuit. A large current detection section consisting of a Hall element that outputs a signal, and a rectifier circuit connected to the secondary side of a current transformer provided with the main circuit conductor as the primary side, detect the current flowing through the main circuit. (Selection between a small current detection section that outputs the signal M, and a selection circuit that selects the output with a higher signal level among the outputs from the large current detection section below. A circuit breaker comprising an overcurrent response section that opens the main circuit contacts on condition that the output from the circuit exceeds a preset value. (2) Main circuit contacts. a main circuit conductor that connects a power supply and a load to form a main circuit; an AC drive circuit that is supplied with power from the main circuit conductor and outputs an AC constant current or AC constant voltage;
It is provided near the main circuit conductor in order to respond to the magnetic field caused by the current flowing through the main circuit, and is biased by the constant AC current or constant AC voltage output from the AC drive circuit, so that the current flowing through the main circuit is large. a large current detection section comprising a first Hall element that outputs a detection signal according to the 1111 current of the main circuit in the region; and a large current detection section provided near the main circuit conductor to respond to a magnetic field due to the current flowing through the main circuit. A circuit with high detection sensitivity that outputs a detection signal according to the current flowing through the main circuit in a region where the current flowing through the main circuit is small by being biased by a constant AC current or a constant AC voltage output from the AC drive circuit. A small current detection section consisting of two Hall elements, a selection circuit that selects the output of the one with a higher signal level among the outputs from this small current detection section and the above-mentioned large current detection +91%, and 2. A circuit breaker comprising: an overcurrent response section that fully opens the main circuit contacts under all conditions that the output exceeds a preset setting jib. (3) A main circuit conductor that has main circuit contacts and connects the power supply and load to form the main circuit, and an AC drive circuit that supplies the main circuit power from this main circuit conductor and outputs a full AC constant current or AC constant voltage. and a DC drive circuit that is supplied with power from the main circuit conductor and outputs a full DC constant current or DC constant voltage; The main circuit is biased by the DC constant current or dDC, constant ηt, and pressure output from the DC drive circuit. Ii The above main circuit conduction in the region where the current is large
a large current detection section consisting of a first Hall element that outputs a detection signal corresponding to the tK current; , "J <mi" Detection that outputs a detection signal according to the current flowing through the main circuit in a region where the current flowing through the circuit is small by being biased by the AC constant current or the constant AC voltage output from the circuit. A small current detection section 1 consisting of a highly sensitive second Hall element, a rectification circuit that rectifies the output from the large current detection section, and a signal level of the output from this rectification circuit and the small current detection section. and an overcurrent response section that opens the main circuit contacts on the condition that the output from the selection circuit exceeds a preset value. A circuit breaker characterized by: