JPH04128041U - Phase loss protection circuit breaker - Google Patents

Abstract

(57) [Summary] [Purpose] In a single-phase three-wire distribution line, the load capacity between both voltage lines and the neutral line has become significantly unbalanced, and the neutral line has become disconnected. To quickly detect an abnormal voltage that appears between both voltage lines and a neutral line in case of an abnormal voltage, and shut off the power distribution system to prevent load electrical equipment from being destroyed by the abnormal voltage. [Structure] In a single-phase three-wire distribution line, an abnormal voltage detector 1 with a transmitting circuit is connected near the load L ₁ L ₂ , and the open-phase circuit breaker with transmitting circuit 1 and a power transformer T are connected.
An open-phase circuit breaker 6 with a receiving circuit is connected between the receiving circuit and the receiving circuit.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is designed to interrupt the circuit when the neutral wire is disconnected in a single-phase three-wire distribution line. The present invention relates to an open phase protection circuit interrupting device that disconnects the load to protect the load from abnormal voltage.

0002

[Conventional technology]

Conventionally, for example, in the 200V single-phase three-wire distribution system shown in Figure 3, the voltage between the voltage lines A A', BB' and the neutral line NN' is each maintained at 1/2 of 200V, that is, 100V. . However, when the capacities of loads L ₁ and L ₂ are significantly unbalanced, if there is a disconnection accident at point C between the neutral line N and N', then A'N' and The voltage between B 'N' deviates significantly from 100V, and becomes an abnormal voltage in which 200V is divided proportionally in inverse proportion to the capacity ratio of loads L ₁ and L ₂ , and in some cases, the electrical equipment of loads L ₁ and L ₂ may There is a risk of being destroyed.

0003

[Problem that the idea aims to solve]

Therefore, in a single-phase three-wire power distribution system, when the neutral line becomes disconnected, it is necessary to quickly detect this state and shut off the power to the power distribution system to protect the loads L ₁ and L ₂ from abnormal voltage. For this reason, conventionally, as shown in FIG. 4, an open phase protection circuit breaker 28 is connected to the single-phase three-wire distribution line, and an abnormal voltage detection circuit 29 is connected between both voltage lines AA', BB' and the neutral line NN'. The output causes the open-phase protection circuit breaker 28 to operate and cut off, thereby protecting the loads L ₁ and L ₂ .

However, in this case, if the disconnection position of the neutral wire NN' is on the power supply side of the phase loss protection circuit breaker 28 and point D marked by X in the figure, the abnormal voltage is input to the abnormal voltage detection circuit 29 and the phase loss The protective circuit breaker 28 can operate to shut off and protect the loads L ₁ and L ₂ , but if the disconnection position is at point E marked by X in the figure, the input voltage to the abnormal voltage detection circuit 29 is normal, so there is no abnormal voltage. cannot be detected and the loads L ₁ and L ₂ cannot be protected.

For this reason, as shown in FIG. 5, an auxiliary terminal 30 is provided on the load side of the open phase protection circuit breaker 28, and an auxiliary neutral terminal for abnormal voltage detection is provided from the neutral point N' near the loads L ₁ and L ₂ . The wire 31 is pulled out and connected to the abnormal voltage detection circuit 29 via the auxiliary terminal 30 to cope with a disconnection at the point E marked by X on the load side of the open phase protection circuit breaker 28.

However, in this case, it is necessary to provide an auxiliary terminal ₃₀ to the open-phase protection circuit breaker 28 and to wire an auxiliary neutral wire 31 to the vicinity of the loads L ₁ and L ₂ . , _L2 have loads _L3 and _L4 branched in parallel, it is necessary to wire one more auxiliary neutral wire 32 from the auxiliary terminal 30, which has the disadvantage of complicating the wiring. Further, if there is a break in the auxiliary neutral wires 31, 32 themselves, there is a problem that abnormal voltage cannot be detected.

[0007]

[Means to solve the problem]

Taking these points into consideration, in the present invention, an abnormal voltage detector 1 with an oscillation circuit consisting of an abnormal voltage detection circuit 2 and a high frequency oscillation circuit 3 is connected near the loads L ₁ and L ₂ , and the An open-phase circuit breaker 6 with a receiving circuit is connected between an abnormal voltage detector 1 with a transmitting circuit and a power transformer T, which includes a receiving circuit 4 and a circuit breaker drive circuit 5.

[0008]

[Effect]

Thus, the abnormal voltage detection circuit 2 in the abnormal voltage detector 1 with a transmitting circuit detects abnormal voltage. When detected, the high-frequency oscillation circuit 3 oscillates and transmits high-frequency current to the single-phase three-wire distribution line. When the receiver circuit 4 in the open-phase circuit breaker with receiver circuit 6 receives the signal, the circuit breaker is activated. Circuit 5 responds by breaking the circuit and protecting the load from the abnormal voltage.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are circuit configuration diagrams of different embodiments of the present invention, and for convenience, the same parts are designated by the same reference numerals. First, in FIG. 1, reference numeral 1 denotes an abnormal voltage detector with a transmitting circuit connected near the loads L ₁ and L ₂ , which is composed of an abnormal voltage detecting circuit 2 and a high frequency transmitting circuit 3. A receiving circuit 4 and a circuit breaker driving circuit 5 are connected between the voltage detector 1 and the power transformer T.

Next, details of the abnormal voltage detector 1 with a transmitting circuit and the open phase circuit breaker 6 with a receiving circuit will be explained. 7 and 8 in the abnormal voltage detector with oscillation circuit 1 are equivalent impedances connected in series between the A-phase voltage line AA' and the B-phase voltage line BB', and are composed of, for example, a resistor, a coil, a capacitor, and the like. 9 is a rectifier bridge connected between the connection point 10 of the equivalent impedances 7 and 8 and the neutral wire NN', 11 is a Zener diode for detecting abnormal voltage, and 12 is a high frequency transistor oscillator. Further, 13 and 14 are inductances and capacitors that determine the oscillation frequency, and a parallel circuit thereof is connected between the Zener diode 11 and the collector of the high-frequency transistor oscillator 12, and a feedback circuit is connected between the base and emitter of the high-frequency transistor oscillator 12. Coil 15 is connected. In addition, 16 and 17 are capacitors for coupling the output coil and power line connected in series between the A-phase voltage line AA' and the B-phase voltage line BB', and 18 is a capacitor for connecting the high-frequency current to the loads _L1 and _L2 . This is a high frequency filter to prevent

[0011] Next, 19 in the open-phase circuit breaker 6 with a receiving circuit is the generator of the abnormal voltage detector 1 with a transmitting circuit. This is a tuned circuit that induces a high-frequency current in tune with the vibration frequency. It consists of a parallel circuit with a capacitor 21, one end of which is connected to the B phase voltage via a capacitor 22. It is connected to the voltage line BB', and the other end is connected to the A-phase voltage line AA'. Also, 23 is the same A diode that detects the high frequency current generated by the thyristor 24. The thyristor 24 is connected to the main contact of the open-phase circuit breaker 6 with a receiving circuit. A tripping coil 26 for driving and opening 25 is connected in series. Also, 27 is a telephone This is a high frequency filter provided to prevent high frequencies from flowing to the source side.

[0012]In addition, when the single-phase three-wire distribution line is branched and wired on the load side of the open-phase circuit breaker 6 with receiving circuit, and there are loads L ₃ and L ₄ in parallel with the loads L ₁ and L ₂ , As shown in FIG. 2, another abnormal voltage detector 1' with an oscillation circuit may be connected near the loads _L3 and _L4 . The usable distance between the abnormal voltage detector 1 with a transmitter circuit and the open phase circuit breaker 6 with a receiver circuit is determined by the output of the high frequency transmitter circuit 3 and the receiving sensitivity of the receiver circuit 4. Of course, the number of abnormal voltage detectors 1 is not limited.

The operation will now be described with reference to FIG. In the single-phase three-wire distribution line shown in Figure 1, if the capacities of loads L ₁ and L ₂ are significantly unbalanced, an Assuming that the circuit becomes disconnected, the DC voltage generated between the connection point 10 of the impedances 7 and 8 and the neutral wire NN' and rectified by the rectifier bridge 9 is transferred to the Zener diode. When the threshold value 11 is exceeded, the high-frequency transistor oscillator 12 oscillates at an oscillation frequency determined by the values of the inductance 13 and the capacitor 14, superimposing the high-frequency current on the power supply lines AA' and BB', and disconnecting the open phase water channel with a receiving circuit. A high frequency current is induced in a tuned circuit 19 consisting of an inductance 20 and a capacitor 21 in the device 6, the output of which is detected by a diode 23, and the detected current triggers the gate of the thyristor 24, causing a drive current to the tripping coil 26. flows, and the main contactor 2 is opened to cut off the power distribution system.

[0014]

[Effect of the idea]

As mentioned above, the present invention can be applied to both voltage lines and neutral line in a single-phase three-wire power distribution system. When the load capacity between the two is significantly unbalanced and the neutral wire is disconnected , quickly detects the voltage that appears between both voltage lines and the neutral line, shuts off the power distribution system, and removes the negative voltage. Of course, it can prevent charged electrical equipment from being destroyed by abnormal voltage. However, in particular, the load side of the open phase protection circuit breaker 28 shown in FIG. 4, the neutral wire N-N' Phase loss protection when there is a disconnection at point E marked X can be easily performed, and is It is necessary to install auxiliary neutral wires 31, 32, etc. for abnormal voltage detection as shown in Figure 5. It has great practical effects such as no

[0015]

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of an open-phase protection circuit interrupting device according to the present invention.

FIG. 2 is a configuration diagram of an embodiment of an open-phase protection circuit interrupting device different from that shown in FIG. 1 according to the present invention;

3 to 5 are diagrams of different conventional single-phase three-wire power distribution systems.

[Explanation of symbols]

1 Abnormal voltage detector with transmitting circuit 2 Abnormal voltage detecting circuit 3 High frequency transmitting circuit 4 Receiving circuit 5 Circuit breaker drive circuit 6 Open-phase circuit breaker with receiving circuit AA' A-phase voltage line BB' B-phase voltage line NN' Neutral Line T Power transformer L ₁ L ₂ load

Claims (1)

[Scope of utility model registration request] [Claim 1] In a single-phase three-wire distribution line, loads L ₁ , L
An abnormal voltage detector 1 with a transmitting circuit is connected near the transmitting circuit ₂ , and an open phase circuit breaker 6 with a receiving circuit is connected between the abnormal voltage detector 1 with a transmitting circuit and the power transformer T. Phase loss protection circuit breaker.