JPS62122105A - Energy absorber - 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] [Field of application of the invention] The present invention relates to an energy absorption device.

[Background of the invention]

Motor 1 In order to suppress the overvoltage caused by the release of electrical energy due to kinetic energy stored in an electromechanical system such as a generator or the release of electrical energy stored in an electrical network, the above-mentioned energy must be absorbed. Must be. The use of a zinc oxide (ZnO) nonlinear resistor is being considered as an overvoltage suppressor used for this purpose.

In order to increase the amount of absorbed energy, it is necessary to use multiple zinc oxide nonlinear resistors connected in parallel, but the relationship between the current ■ and the voltage V of the zinc oxide nonlinear resistor is IoeV'
Because of the excellent nonlinearity of the voltage and current characteristics with a large nonlinearity index α, a large imbalance tends to occur in the current flowing between the zinc oxide nonlinear resistors connected in parallel.

This is due to slight differences in characteristics, and the ratio between the maximum and minimum currents that flow through the plurality of zinc oxide nonlinear resistors reaches 100 to 1000 times.

For this purpose, as shown in FIG. 3 of JP-A-58-222502%+, for example, resistors 3 and 4 are connected in series to each of two electrical circuits composed of zinc oxide nonlinear resistors 1 and 2. It is inserted to balance the current.

In the figure, numerals 5 and 6 are terminals of an energy absorbing device having a plurality of electrical circuits connected in parallel. By the way, in the energy absorption device configured in this way, when a large current such as a lightning impulse current flows, the voltage drop across the resistors 3 and 4 connected in series becomes excessive, resulting in dielectric breakdown of the resistors 3 and 4. there were. Furthermore, if any one of the plurality of electrical circuits connected in parallel develops a problem and becomes short-circuited, the function of the entire device is impaired.

[Purpose of the invention]

The present invention was made in view of the above points, and it prevents dielectric breakdown of a resistor connected in series with a zinc oxide nonlinear resistor, and prevents the entire device from being damaged even if a failure occurs in a part of the parallel circuit group. The purpose of this invention is to provide an energy absorbing device that can maintain its functionality.

[Summary of the invention]

The present invention includes a plurality of electrical circuits connected in parallel,
In the electric circuit, the relationship between the electric current and the voltage V is ``OCV'' (α
is a nonlinear index), and
In an energy absorbing device that is connected in series to this non-linear resistor and has a resistor having an index smaller than a non-linear index α of the non-linear resistor, the absorber has a voltage drop across the resistor. The device is characterized by being equipped with a protective zinc oxide non-linear resistor that suppresses the voltage drop below the allowable value, and a cutoff device that prevents short-circuiting of the electric circuit, thereby reducing the voltage drop across the resistor below the allowable value. This will prevent short circuits in the electrical circuit.

The inventors have determined how to prevent dielectric breakdown of the resistor connected in series with the zinc oxide nonlinear resistor and maintain the functionality of the entire device even if a failure occurs in part of the parallel circuit group. We considered whether it could be done.

As shown in FIG. 3, zinc oxide nonlinear resistor 1.
The resistors 3 and 4 connected in series with the zinc oxide nonlinear resistor 1.2 may be linear resistances or nonlinear resistances with an index smaller than the nonlinear index α of the zinc oxide nonlinear resistor 1.2.
, 4, the voltage drop across the resistors 3 and 4 is proportional to the current. Therefore, the voltage drop across a resistor in a circuit carrying a large current is greater, and as the current increases, the voltage drop increases and eventually exceeds the creeping withstand voltage of the resistor. The creepage withstand voltage of various resistors was investigated and compared with that of a zinc oxide nonlinear resistor, and the results are shown in FIG.

In the figure, the horizontal axis shows various resistors, and the vertical axis shows zinc oxide non-linear a
The ratio between the creeping withstand voltage of the resistor and the creeping withstand voltage of the resistor under test was set at 7. As is clear from the figure, the creeping withstand voltage of the zinc oxide resistor, sintered carbon resistor, and silicon carbide thread resistor tested is almost equal to the creeping withstand voltage of the zinc oxide nonlinear resistor shown by the dotted line in the figure. 6 Therefore, it must be used in a current range where the maximum voltage and pressure drop of the resistor is less than the voltage drop of the zinc oxide nonlinear resistor, but in order to do so, a large current in the electrical circuit is required. parallel to multiple electrical circuits so that when the current flows and the voltage drop across the resistor becomes large to a certain extent, that large current is suppressed from flowing through the resistor.

Alternatively, a protective zinc oxide nonlinear resistor may be provided in parallel with at least one resistor. By doing this, since the protective zinc oxide nonlinear resistor has nonlinear characteristics, the large current in the electrical circuit is transferred from the resistor to the protective zinc oxide nonlinear resistor, which has nonlinear characteristics. It was confirmed that most of the current was shunted, and the large current flowing through the resistor was suppressed to a small extent, and that the increase in voltage drop in the resistor was suppressed to below an allowable value. Also,
If a circuit breaker is installed in series with the electrical circuit, the circuit in which the problem occurs will be shut off by the circuit breaker.

It was confirmed that short-circuiting of otherwise healthy electrical circuits was prevented, and that the entire device was prevented from functioning. Therefore, in the present invention, the absorption device includes a protective zinc oxide non-linear resistor that suppresses the voltage drop of the resistor to below a permissible value, and an interrupter that prevents a short circuit in the electric circuit.

A device was installed. By doing this, it is possible to prevent dielectric breakdown of the resistor connected in series with the zinc oxide nonlinear resistor, and to maintain the functionality of the entire device even if a failure occurs in part of the parallel circuit group. This made it possible to obtain an energy absorbing device with high energy efficiency.

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. FIG. 1 shows an embodiment of the invention. Note that the same parts as in the prior art have been given the same reference numerals, so their explanations will be omitted. 8 and
Interrupting devices 9 and 10 are provided to prevent short circuits in the electric circuit. By doing so, the absorption device includes a protective zinc oxide non-linear resistor 7.8 that suppresses the voltage drop across the resistors 3 and 4 below an allowable value, and a disconnection device 9 and 10 that prevents a short circuit in the electric circuit. As a result, the voltage drop across the resistor 3.4 is suppressed to a permissible value or less, and a short circuit in the electric circuit is prevented. It is possible to obtain an energy absorbing device that prevents dielectric breakdown of the body 3.4 and maintains the function of the entire device even if a failure occurs in a part of the parallel circuit group.

That is, protective zinc oxide non-linear resistors 7 and 8 were provided in parallel with the resistors 3 and 4 of the parallel circuits, and blocking bags [9 and 10 were provided in series with the respective circuits. By doing so, the protective zinc oxide nonlinear resistor 7 is provided in parallel with the resistor 3, and the protective zinc oxide nonlinear resistor 8 is provided in parallel with the resistor 4.
are now provided, and interrupting devices 9 and 10 are provided in series on each of the two electrical circuits. Therefore, terminal 5
In a range where the voltage between ゜6 is small to a certain extent, most of the current flowing through the electric circuit flows almost equally through the resistors 3 and 4, but
When the voltage between terminals 5 and 6 increases, most of the current flowing through the electrical circuit flows through protective zinc oxide nonlinear resistors 7 and 8, suppressing an increase in the current flowing through resistor 3.4. As a result, the voltage drop across the resistors 3 and 4 can be suppressed to below a permissible value, and the creeping withstand voltage of the resistors 3 and 4 can be maintained to prevent dielectric breakdown thereof.

This is clear from FIG. 2, which shows the relationship between voltage and current between terminals 5 and 6, with voltage on the vertical axis and current on the horizontal axis. As shown in the same figure, in region I, the current flowing through each parallel circuit is small, and the effect of resistors 3 and 4 does not appear, and in region 2, the current in each circuit becomes large, and 4, the effect of dividing and equalizing the flow becomes remarkable. When the current increases further and reaches the region ■, the resistor 3
, 4 is connected in parallel to the protective zinc oxide nonlinear resistor 7.8, the current flowing through the resistor 304 is shunted, and the voltage drop across the resistors 3 and 4 is suppressed.
This protects the resistors 3 and 4.

The voltage drop of the protective zinc oxide nonlinear resistors 7 and 8 is set to be the same as that of the zinc oxide nonlinear resistor 1.2 for the same current.

In addition, since the parallel circuits are provided with interrupting devices 9 and 10 in series, even if a malfunction occurs in the zinc oxide nonlinear resistor 1 or the resistor 3 during energizing operation, resulting in a short circuit, these oxidized A fault current flowing through the electrical circuit having the zinc nonlinear resistor 1 and the resistor 3 is interrupted by the interrupting device 9. Therefore, the functionality of the entire acid device can be maintained.

As the interrupting devices 9 and 10, power fuses, vacuum circuit breakers, etc. are small and simple, but when using a circuit breaker such as a vacuum circuit breaker, a fault current detection element is provided in the electrical circuit, and the circuit breaker is opened. All you have to do is make it perform the action.

Although the present embodiment has been described with reference to the case where two electric lines are connected in parallel, it goes without saying that the present invention is not limited to this and the same applies even when more electric lines are connected in parallel.

Another embodiment of the invention is shown in FIG.

In this example, a protective zinc oxide nonlinear resistor 7 was connected in parallel with one resistor 3. That is, the protective zinc oxide nonlinear resistor 7 was provided for only one resistor 3. In this case as well, when the voltage between the terminals 5 and 6 increases, the current flowing through the protective zinc oxide nonlinear resistor 7 increases and the resistor 3
, 4 are now shunted, and the same effects as in the case described above can be achieved.

FIG. 6 shows yet another embodiment of the present invention. In this embodiment, a protective zinc oxide nonlinear resistor 11 was connected in parallel with a plurality of electrical circuits. A cutoff device 12 was connected in series with the protective zinc oxide nonlinear resistor 11. In this case as well, when the voltage between the terminals 5 and 6 increases, the current flowing through the protective zinc oxide nonlinear resistor 11 increases and the resistors 3 and 4
The current is shunted, and the same effects as in the case described above can be achieved.

FIG. 7 shows yet another embodiment of the invention. Electrical circuits connected in parallel, ie zinc oxide non-linear resistor 1.
Resistor 3. An electric circuit having a protective zinc oxide nonlinear resistor 7, a zinc oxide nonlinear resistor 2, a resistor 4. The electrical circuit having the protective zinc oxide nonlinear resistor 8 was connected in parallel to form one parallel electrical circuit. And zinc oxide nonlinear resistor 13
．． Resistor 15. An electric circuit having a protective zinc oxide nonlinear resistor 17 and a zinc oxide nonlinear resistor 14. The resistor 16 and the electrical circuit having the protective zinc oxide nonlinear resistor 18 were connected in parallel to form one parallel @ circuit.

And each interrupting device 9 is connected in series to one of these parallel circuits.
, 10 were provided to constitute an energy absorption device. By doing this, the interrupting devices 9 and 10 can be installed on parallel circuits in which two circuits are connected in parallel.
The number of installed cutoff devices 9 and 10 can be reduced compared to the case described above. Note that in this embodiment, two electric lines are connected to form one parallel electric line, but it goes without saying that the number of electric lines connected in parallel is not limited to two.

〔Effect of the invention〕

As described above, the present invention prevents dielectric breakdown of the resistor connected in series with the zinc oxide nonlinear resistor, and maintains the functionality of the entire device even if a failure occurs in a part of the parallel circuit group. Energy absorption prevents dielectric breakdown of the resistor connected in series with the zinc oxide non-linear resistor) and maintains the functionality of the entire device even if a failure occurs in part of the parallel circuit group. You can get the equipment.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the device configuration of an embodiment of the energy absorption device of the present invention, FIG. 2 is a characteristic diagram showing the relationship between voltage and current between terminals of the same embodiment, and FIG. 3 is a conventional FIG. 4 is a characteristic diagram comparing the creeping voltage of various resistors and that of a zinc oxide nonlinear resistor, and FIG. 5 is a circuit diagram showing the structure of the energy absorbing device of the present invention. FIG. 6 is a circuit diagram showing the device configuration of yet another embodiment of the energy absorbing device of the present invention, and FIG. 7 is a circuit diagram showing the device configuration of yet another embodiment of the energy absorbing device of the present invention. FIG. 2 is a circuit diagram showing the device configuration of the embodiment. 1.2... Zinc oxide nonlinear resistor, 3, 4... Resistor, 5.6... Terminal, 7, 8... Zinc oxide nonlinear resistor for protection, 9, 10... - Shutoff device, 11... Zinc oxide non-linear resistor for protection, 12... Shutdown device, 13.
14...Zinc oxide nonlinear resistor, 15.16...Resistor, 17.18...Zinc oxide nonlinear resistor for protection. Moga 3 harden Koga 4 hard

Claims (1)

[Claims] 1. A plurality of electric circuits connected in parallel are provided, and the electric circuit has a relationship between current I and voltage V of I V^α (α is a nonlinear index).
An energy absorption device comprising a zinc oxide nonlinear resistor represented by: and a resistor connected in series to the nonlinear resistor and having an index smaller than the nonlinear index α of the nonlinear resistor, An energy absorbing device characterized in that the absorbing device is provided with a protective zinc oxide non-linear resistor that suppresses a voltage drop across the resistor below a permissible value, and a cutoff device that prevents a short circuit in the electric circuit. 2. The energy absorbing device according to claim 1, wherein the protective zinc oxide nonlinear resistor is connected in parallel with at least one of the resistors. 3. The energy absorption device according to claim 1, wherein the protective zinc oxide nonlinear resistor is connected in parallel with the plurality of electric circuits. 4. The energy absorbing device according to claim 1, wherein the interrupting device is connected in series with the electric circuit.