JPH0367429A - High-speed dc vacuum breaker - Google Patents

Abstract

PURPOSE:To shrink a mounting volume by providing a vacuum valve, a serial body of a capacitor and a switch, and an element dissipating the energy of the stray inductance of a wiring, and selecting the oscillating frequency of a closed circuit including the vacuum valve, capacitor and switch, the commutation inductance, and the commutation current to preset values. CONSTITUTION:A main current flows in a vacuum bulb V1, and a capacitor C is charged. When a switch S is closed after a pole is opened, an oscillating current starts to flow from the capacitor C in the opposite direction to the main current. The residual current at the arc-extinguishing moment is fed to a ZnO nonlinear resistor ZNLR having the capacity of about 2000 times the capacity of V1 when the pole is opened, and the rise of the peak voltage across bulb electrodes is prevented. When the charging current of the capacitor C is increased and the discharge starting voltage of the resistor ZNLR is attained, a current flows, the energy in a main circuit L is dissipated, and the main current is attenuated and cut off. The oscillating frequency of the oscillating current is selected to 2kHz or above, the peak commutation current to 5000A or above, and the commutation inductance L>1muH or above. Stray inductance may be used for the commutation reactor, the commutation capacity can be made small, thus the occupied volume is made extremely small.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a DC circuit breaker using a vacuum valve.

[Conventional technology]

Trains and electric locomotives (hereinafter referred to as electric locomotives) are prone to short-circuit failures due to damage to elements used in the main circuits of inverters and choppers (thyristors, gate turn-off thyristors, transistors, etc.), and ground failures due to poor insulation of some wiring in the main circuit. There is an inherent possibility that failures such as circuit failures or abnormal increases in current due to control system failures may occur. If such failures are left untreated, there is a risk of equipment burnout, so to prevent this from happening, electric cars have traditionally been equipped with circuit breakers that cut off excessive current. .

However, due to the structure of conventional air circuit breakers, the speed from when fault current flows to when the fault current is interrupted is slow, and the electric vehicle is interrupted before the circuit breaker operates. There were cases where the circuit breaker installed at the above-ground substation in the existing feeding section operated first. When the above-ground substation's circuit breaker operates, the electric heavy metals located within the feeder section to which the substation supplies power will stop receiving power. In other words, an accident involving an electric vehicle will spread to other electric vehicles. If such an accident were to occur on a line with an overcrowded timetable, it is easy to imagine that it would affect not only the electric cars in that section but also the electric cars in other sections.

This is due to the slow breaking speed of the above-mentioned air circuit breaker mounted on the vehicle.

Therefore, in recent years, a DC vacuum circuit breaker has become necessary as a faster circuit breaker.

Interrupting direct current is more difficult than interrupting alternating current because direct current does not have a current zero point, as described in Japanese Unexamined Patent Publication No. 132776/1983. To solve this problem, in DC cutoff, a commutating capacitor is installed in parallel with the on-off valve (hereinafter referred to as the valve), and an oscillation circuit (commutating circuit) is formed with the inductance of the circuit to artificially create a current zero point. ing.

This method is roughly divided into two types: preliminary charging method and non-charging method.

In the pre-charging method, the capacitor is charged in advance, and when the valve is opened, the charge stored in the capacitor is discharged, causing vibrations between the capacitor and the inductance. Since this oscillation circuit has a pure resistance component, the amplitude of vibration decreases exponentially. When the initial amplitude of this vibration passes through the current zero point, the arc current in the bulb disappears and the interruption is completed.

The non-charging method uses a bulb with negative arc characteristics, connects a capacitor in parallel to this bulb, and obtains a divergent oscillating current when the bulb is opened. The vibration is cut off when the amplitude of the vibration in the divergence direction passes through the zero point. but,
This method requires a certain amount of time for the vibration to increase and pass through the zero point. Therefore, it is conceivable that the circuit breaker at the above ground substation will be activated by then.

Therefore, it is convenient for the circuit breaker installed in electric vehicles to be pre-chargeable.

The pre-charging type DC breaker described in Japanese Patent Application Laid-Open No. 132776/1980 is as follows.

If you simply connect a capacitor in parallel with the bulb to form a resonant circuit with stray inductance, the current slope, which is the time differential (di/dt) when the current flowing through the bulb crosses the current zero point, will be too large and difficult to interrupt. . Therefore, in order to reduce the current slope, not only the stray inductance but also an inductance of several millihenries (mH) or more is connected in series with the capacitor.

[Problem to be solved by the invention]

The size of the capacitor and inductance of the above conventional technology is changed. If the inductance is several mH, the capacitor will be several thousand to several hundred microfarads (μF), and its volume itself will be quite large.

Electric cars have equipment installed under the floor or on the roof, and the space for installing equipment is extremely limited, so if the equipment is too large, it cannot be mounted on an electric car.

An object of the present invention is to provide a DC vacuum circuit breaker using a pre-charging method that can be installed on electric vehicles.

[Means to solve the problem]

In order to achieve the above object, a vacuum valve for cutting off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a means connected in parallel to the vacuum valve, In a device equipped with an element that consumes energy stored in stray inductance of wiring through which direct current flows, the vibration frequency of the closed circuit including the vacuum valve, capacitor, and opening/closing means is reduced to 2.
KHz or more, commutation current is 5000A or more, and commutation inductance included in the closed circuit is 1 μH or more.

[Effect]

Since the above means allows the vibration frequency of the commutation circuit to be 2 KHz or more, the commutation reactor can be used even with stray inductance, and the commutation capacitor can be made considerably smaller. Therefore, it can be installed even under the floor of an electric car, which is narrow.

〔Example〕

According to the above-mentioned Japanese Patent Application Laid-Open No. 54-132776, in the pre-charging method, the frequency of the oscillating current due to the commutating capacitor and inductance connected in parallel to the valve is IKH.
It was believed that if it exceeded z, it could not be shut off reliably. This is because the fIt flow gradient becomes large.

Next, the relationship between the vibration frequency, inductance, and capacitor of a DC breaker will be briefly explained.

The breaking ability of a circuit breaker (the ability to cut off the main FA current) depends on the magnitude of the commutation current, in which the current from the precharged commutation capacitor flows in the opposite direction to the main current. . In other words, in order to extinguish the arc generated in the bulb, the peak value of the commutation current must be larger than the main current.

Commutation current i is given by the following formula.

Here, R: Pure resistance of the commutation circuit L: Inductance of the commutation circuit C: Capacity of the commutation capacitor If the commutation circuit is constructed of wires with a sufficient cross-sectional area, the resistance will be:
It can be considered as zero. Therefore, equation (1) is: From equation (2), the peak value of the commutation current is: In order to increase the commutation current Ip, either increase the charging voltage V of the commutation capacitor or the capacitance C of the capacitor, or All you have to do is make the inductance L smaller.

On the other hand, the natural frequency fo of the commutation circuit is expressed by the following formula.

Therefore, when determining the inductance L and the commutating capacitor C, the frequency io and the maximum current Ip are determined by the following formula.

IpC=...
・(5) 2πfV ■ C= ・・
- (6) 2πfIP Therefore, as a method of reducing the commutation capacitor capacity C without changing the commutation capacity, it is conceivable to increase the commutation capacitor charging voltage ■. However, in this case, there is a problem that the inductance L becomes large, and from the viewpoint of insulation voltage design with each device, it is difficult to use the capacitor charging voltage V extremely high compared to the circuit voltage. This is not a good idea because the circuit equipment becomes larger.

Based on the above formula. Figure 2 shows the relationship among the capacitor capacitance C, inductance L, and commutation current peak value ■.

For example, if the frequency is the aforementioned I KHz and the commutation current is 10
Considering KA, the capacitance of the capacitor is 1.000μF.
, the inductance is 20μH, and the size of a capacitor with this capacity is generally HaOO ugly, depth 500m++
, and is said to be about 500 na in height. This is too large to be mounted under the floor of an electric car.

It can be easily understood from FIG. 2 that in order to reduce the commutation capacitor capacitance C and the commutation inductance L, the frequency fo of the commutation circuit should be increased.

However, the above-mentioned Japanese Patent Application Laid-open No. 54-132776 and
As stated in the Journal of the Institute of Electrical Engineers of Japan, June 1973, Vol. 98, No. 6, DC Breaker for Critical Plasma Testing Equipment JT-60, page 44, it has been shown that the frequency of commutation current is limited to about 1 KHz. has been done. This is said to be because if the current reduction rate near the current zero point is large, it is difficult for the valve to interrupt the current.

If this continues, commutation capacitor C and commutation inductance L cannot be reduced.

Here, the vacuum circuit breaker will be briefly explained.

When a valve is opened in air with a current flowing through it, the atoms present between the electrodes are ionized. This flow of ions is an arc. On the other hand, since there are no atoms between the electrodes in a vacuum, in principle no arc is generated when the valve is opened in a vacuum. A vacuum circuit breaker is an application of this principle. This is why vacuum circuit breakers operate at high speed. However, it is extremely difficult to create a complete vacuum, and in reality, an arc is generated due to an arc voltage of several tens of volts due to reasons such as ionization of metal atoms in the melted electrode when the valve is opened. current continues to flow. A commutation circuit is required to extinguish this arc.

Now, returning to the original topic, it is possible to reduce both the capacitor and inductance by increasing the commutation frequency, but there is a limit to the maximum value of the commutation frequency, and it is considered impossible to achieve this. Ta.

Therefore, the inventors of the present invention attempted the following experiment.

FIG. 11(a) shows the measurement circuit. The current from the DC power supply E becomes a fault current via the variable loads Lm and R*. First, turn off line breaker LB.

Leave the vacuum valve VI in the connected state. Main current It,,
Ic, voltage when opening the vacuum valve VCB is mainly am
It was decided to. The experimental method was to turn on the line breaker LB which was in the OFF state to generate a fault current, and when the detected value of the overcurrent detector CT exceeds the set value, a trip command is issued from the control unit, the repulsion coil is energized, and the vacuum Valve V
I is opened so that the current is cut off. Next, the line breaker LB is set to 0FFL, a reset command is given, the vacuum valve VI is closed, and the next experiment is started.

Because this experiment was conducted in an area that was conventionally said to be impossible to shut off, the first few times (Tables 1 to 4 below) the overcurrent detector CT was not used, and trip commands were issued in time within the control unit. Therefore, the set values described below are not displayed.

Next, terms will be explained with reference to FIG. 11(b).

The solid line in the figure is the current IL, and the - dotted line is the current curve when the fault current continues to flow without being interrupted. The set value is the operating current value at which the circuit breaker is operated when the detection value of the overcurrent detection device CT reaches, and the actual breaking current is the actual operating point of the circuit breaker. Moreover, the breaking current indicates the breaking ability of the circuit breaker.

Next, the table shows the experimental results in which the blockage was actually successful.

From this table, power supply voltage 1600 (V), set value 20
80 (A) and a commutation frequency of 11.1 (KHz). The commutation frequency is about 10 times the conventional value. By making this commutation frequency high, it was possible to omit the commutation reactor and use only the stray inductance in the wiring as the inductance component, and the commutation capacitor was also able to have a small capacity of 50 μF.

The above stray inductance is 1 (
μH) remains, so the commutation frequency is approximately 30 (KH
z) ~40 (KHz) is the limit.

By the way, the value of the commutation capacitor at this time is approximately 30 (μH)
It is.

Next, one embodiment of the present invention will be described using FIG.

The main current from the DC power supply E reaches the load LOAD via the vacuum valve VI and the static overcurrent trip device 1sOTD. A series body of a commutating capacitor C and a commutating switch S serving as an opening/closing means is connected in parallel between the poles of the vacuum valve VI. In addition, in a separate loop from the commutation capacitor C, etc., connect the zinc oxide nonlinear resistor ZNLR in parallel with the true valve VI.
is connected. The stray inductance of this closed circuit is smaller than that of the closed circuit caused by the commutating capacitor C and the like. In other words, the wiring length of the closed circuit composed of the zinc oxide nonlinear resistance ZNLR and the vacuum valve VI is shorter.

Although not shown, at both ends of the commutating capacitor C,
The charging circuit is connected.

The vacuum valve VI operates when the static overcurrent extraction device 5OTD detects an abnormal current.

The operating principle of the present invention will be explained below with reference to FIG.

FIG. 3(a) depicts the main current flowing through the closed vacuum valve VI.

Further, the commutating capacitor C is charged in the direction shown in the figure. When an opening command is issued due to a failure condition, first, the vacuum valve VI is opened as shown in (b). Even after opening, the main current continues to flow in the vacuum as an arc, and an ON command is issued to the sixth commutation switch S, which closes as shown in (Q).

At that moment, the electric charge charged in the commutating capacitor C is as follows: commutating capacitor C → stray inductance L → commutating switcher S
→ Vacuum valve VI → Since a closed circuit of commutating capacitor C is formed, an oscillating current in the opposite direction to the main current begins to flow. Eventually, when the current in the vacuum valve VI becomes close to zero (several amperes), the arc is extinguished. However, even if the arc is extinguished, there is usually a residual current (the current that was flowing through the vacuum valve VI as an arc), and the moment the arc extinguishes, a peak voltage (d v/dt) will be applied to the vacuum valve VI. In this embodiment, the zinc oxide nonlinear resistance Z
Since the wiring length of the NLR is shorter than that of the commutation circuit, the inductance is reduced. Therefore, with respect to a changing current, the current flows more easily to the zinc oxide non-direct resistor ZNLR than when the inductance is large.

The zinc oxide nonlinear resistance ZNLR has a capacitance, and its size is approximately 2.000 times the capacitance when the vacuum valve VI is open.

Based on the above, the phenomenon of preventing arc re-ignition of the vacuum valve VI will be explained.

The residual current at the moment the arc is extinguished flows toward the capacitance where it flows most easily, in this case, the zinc oxide nonlinear resistance ZNLR. Therefore, the peak voltage is the vacuum valve Vl
It is possible to prevent the arc from being applied again, thereby preventing the arc from being re-ignited.

Although zinc oxide nonlinear resistance is typically used in the above example, other elements may be used as long as they have constant voltage characteristics, are energy consuming, and have a certain amount of capacitance. You may use it.

Furthermore, it is said that the peak IP of the commutation current is preferably 1.2 times or more the actual breaking current. The magnitude of the actual breaking current is determined by the output of the electric vehicle or the like serving as the load and the DC power supply voltage. Considering the output of an electric vehicle of about 500 Kw to 6000 Kw and the DC power supply voltage of about 600 V to 3000 V, the magnitude of the commutation current Ip is preferably 5000 (A) or more.

As a result, the arc is completely extinguished, and the main current charges the commutating capacitor C (FIG. 3(d)).

The constant voltage of the zinc oxide nonlinear resistor ZNLR is selected to be larger than the power supply voltage E, and when the voltage of the commutating capacitor C increases and the current switch S is opened as shown in e), the energy stored in the inductance of the main circuit is transferred. Consume. In this case, the zinc oxide nonlinear resistance ZNLR operates as a resistor.

Next, the waveforms of each part when tripped will be explained using FIG. 5.

In FIG. 5, the horizontal axis shows the passage of time.

Assume that the main current gradually increases due to an accident and exceeds the overcurrent set value in (a). An overcurrent is detected, an H-pole command is given to the main pole, and the pole is opened at (b).

The main current continues to flow as an arc through the gap in the vacuum.At the 0th order (c), the commutation switch S is closed and the commutation current begins to flow. The current flowing through the vacuum valve cancels out the commutation current and eventually becomes zero (d) 0 Next, the remaining main current at the moment the arc is extinguished is the zinc oxide nonlinear resistance ZNL.
Flows toward R to prevent a sharp rise in voltage between the vacuum valve VI poles.

After that, the amount flowing into the commutation capacitor C increases, and eventually,
When the discharge starting voltage of the zinc oxide nonlinear resistor ZNLR is reached e), current flows through the zinc oxide nonlinear resistor ZNLR, the energy stored in the inductance of the main circuit is consumed, the main current attenuates, and complete cutoff is completed. (f).

The arrangement of the above circuit will be explained using FIG. 4.

Figure 4 shows the storage box H5VCB that houses the vacuum valve and excitation coil of the DC high-speed vacuum circuit breaker, and the commutation capacitor C.
9 is a layout diagram of the interior of a storage box that houses commutation switch S, zinc oxide nonlinear resistor ZNLR1, and other equipment and is installed under the floor of an electric car. This diagram shows the storage box viewed from above, that is, the view from the side of the electric vehicle. 6 Originally, we wanted to minimize the wiring length of the closed loop that includes the commutating capacitor C, but from the diagram As can be seen, commutation capacitor C is large, so it is difficult, so zinc oxide nonlinear resistance ZN
This is done by shortening the LR wiring. By the way, the size of this storage box is Tll11550mm, length 600cm, height 5.
It is 00an. The reason for the low height of 500mm is that it can be used for linear motor subways.

The above experimental results and examples are summarized below. From the two prior art cases mentioned above, it was found that commutation current cannot be cut off at a frequency of IKHz or higher. It is the breaking current slope (
di/dt) was too large, resulting in re-ignition. However, in experiments conducted by the present inventors, it was found that it is possible to block even frequencies of IKHz or higher.

As a result, in the above-described embodiment, no beam axle is inserted into the commutation circuit, that is, the inductance of the commutation circuit is only the stray inductance due to wiring. Assuming that value to be 5 μH, calculate the frequency of commutating current of commutating capacitor C2.

The charging voltage is 1500V, and the maximum commutation voltage is I.
If p is calculated using 600OA, C=80 (μF), and the commutation frequency f at this time is j:□ (8)2ππ here f28 (KHz).

As mentioned above, the effect of this embodiment is not only that the commutation capacitor is made smaller and the commutation reactor is omitted, but also that even if the interruption fails at the first zero point for some reason, the higher frequency will run until the next zero point. This also has the effect of reducing the amount of time required.

Next, the case where the above-mentioned DC high-speed vacuum circuit breaker is used in an electric vehicle will be explained using FIG. 6.

Normally, the DC high-speed vacuum circuit breaker HSVCB is in a closed state. Next, bring the pantograph into contact with the overhead wire and turn on the line breakers LBI and CHK.

Filter capacitor FC with large capacity is connected to charging resistor CH
Charged via Re. After charging is complete, line breaker L
B2 is turned on and becomes ready for operation.

When a driver operates a main controller (not shown), a main motor control section operates an electric motor (not shown) according to the amount of operation.

When the driver turns off the main motor during forward driving, the main motor control section (particularly in the case of an inverter) reduces the main current, and then opens and interrupts the line breakers LBI and LB2. This is called a flow cutoff.

Next, we will explain what happens during an accident.

In this case, there are two ways to detect an accident.The first is when the overcurrent detector CT detects a main current higher than the set value, and the second is when a failure of an element etc. is detected within the main motor control unit and an external trip is detected. This is the case when a command is sent.

When these signals are input to the control unit inside the DC high-speed vacuum circuit breaker H5VCB (hereinafter referred to as the control unit), the control unit sends a trip command to the repulsion coil 1, and the repulsion force causes the vacuum valve VI to The pole is opened and locked in that state by the locking mechanism.

Next, when the commutation current reaches a point where the commutation current effectively works (it operates in time), the control unit sends a commutation command to the repulsion coil 2 and operates the commutation switch S.

Then, a commutating current flows from the pre-charged commutating capacitor C, and the interruption is completed as described above. When the interruption is completed, the main current becomes zero, so the control section sends out an LB off command and opens the line breakers LBI and LB2.

Once the accident has been resolved, the driver presses the reset button switch on the driver's cab to start the reset operation.

When a reset command is input to the control unit, the control unit sends the reset command to the reset coil, the lock mechanism is released, and the vacuum valve VI is closed. Next, a charging current is applied to charge the commutating capacitor C to a predetermined value, and the DC high-speed vacuum circuit breaker HSVCB enters a standby state.

According to this embodiment, a high-performance DC high-speed vacuum circuit breaker that is especially compact for electric vehicles can be installed in electric vehicles, and even in the event of an accident, it can interrupt the fault current faster than a circuit breaker at an above-ground substation. It does not have a big impact on other electric vehicles.

Another embodiment of the present invention will be described using FIG. 7.

This diagram differs from Figure 1 in that the zinc oxide nonlinear resistor ZNLR is connected in parallel to the commutation circuit (circuit including commutation capacitor C and commutation switch), and the surge absorption capacitor Cs is connected to the vacuum valve. It is connected in parallel near the VI (so that the wiring length is shorter than the closed loop of the commutation circuit).

In this circuit, when commutated current flows into the vacuum valve vI and the arc is extinguished, most of the remaining current at the time of arc extinguishing flows into the surge absorption capacitor Cs, suppressing the voltage increase rate and suppressing re-ignition.

The capacitance of this capacitor Cs should be selected to be larger than the capacitance when the vacuum valve is open; however, if it is too large, the shape becomes too large, making it unsuitable for electric vehicles.

The advantage of this embodiment is that the capacity of the surge absorption capacitor Cs can be selected as desired.

For example, if the zinc oxide nonlinear resistance ZNLR is large, the stray inductance cannot be made sufficiently small. In this case, a surge absorption capacitor Cs having a small size may be selected.

Other embodiments will be described using FIG. 8.

The difference from the configuration shown in FIG. 7 is that a resistor R is connected in parallel to the zinc oxide nonlinear resistor ZNLR.

When the vacuum valve VI is opened and shut off and the zinc oxide nonlinear resistor ZNLR operates, if the energy stored in the stray inductance from the DC power source E is large, the resistor R
also consumed. Therefore, the burden on the zinc oxide nonlinear resistance ZNLR is reduced. However, in this case, the main current does not disappear completely and continues to flow in the order of DC power supply E → resistor R → load LOAD, so a switch to cut off the low current will be required.

Another embodiment will be described using FIG. 9.

The difference in configuration from Fig. 8 is that the zinc oxide nonlinear resistance ZNL
This is the point where R is missing. Only the resistance R consumes the energy stored in the stray inductance. For the resistance R, like zinc oxide nonlinear resistance ZNLR,
Since there is no constant voltage characteristic, the current flows freely. Again, other breakers would be required.

According to this embodiment, since the structure is simple and inexpensive, it is suitable for interrupting a relatively small current.

Another embodiment will be described using FIG. 10.

The difference from Fig. 7 is the zinc oxide nonlinear resistance ZNL.
R is connected in parallel to the surge absorption capacitor Cs.

This is effective when the zinc oxide nonlinear resistance ZNLR alone has insufficient capacity and there is a possibility of restriking.

〔Effect of the invention〕

According to the present invention, it is possible to have the ability to cut off the oscillating current of the commutation current up to a higher frequency, so the commutation capacitor can be made smaller and lighter, and the commutation reactor can reduce the stray inductance of the wiring at a minimum. This makes it possible to make the DC high-speed vacuum circuit breaker more compact.

Therefore, a vacuum circuit breaker with good high-speed performance can be installed under the floor of an electric vehicle, and even if a failure occurs, there is no need to operate the circuit breaker at the ground substation, and other electrical heavy equipment can be stopped. disappears.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing the relationship among commutation capacitor capacity, commutation inductance, commutation frequency, and commutation current, and Fig. 3 is a diagram showing the commutation principle of the present invention. 4 is a diagram showing the DC high-speed vacuum circuit breaker according to the present invention housed in a storage box, Figure 5 is a diagram showing operating waveforms, and Figure 6 is a diagram showing the DC high-speed vacuum circuit breaker according to the present invention in an electrical 7 to 10 are diagrams showing other embodiments, and FIG. 11 is a diagram showing an experimental device. H8VCB...DC high speed vacuum circuit breaker, VI...Vacuum valve, C...Commuting capacitor, L...Commuting inductance (including stray only), S...Commuting switch, MRC・...Electromagnetic repulsion coil, SRC...Short ring, 5OTD...Static overcurrent trip device, ZN
LR...Zinc oxide non-linear resistance, E...DC power supply, LOAD...Load, Cs...Surge absorption capacitor, R...Linear resistance. Fig. 1 Fig. Fig. Oc capacitance (pF) -- Fig. 4 Fig. Fig. 7 Fig. Fig. Fig. 10

Claims (1)

[Claims] 1. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a series body connected in parallel to the vacuum valve. , and an element that consumes energy stored in stray inductance of wiring through which direct current flows, the vibration frequency of the closed circuit including the vacuum valve, capacitor, and switching means is set to 2 KHz or more, and the commutation current is set to 5000 A or more. and the commutation inductance included in the closed circuit is 1μ
DC high-speed vacuum circuit breaker with H or higher. 2. The DC high-speed vacuum circuit breaker according to claim 1, wherein the energy consuming element is a nonlinear resistance element. 3. The DC high-speed vacuum circuit breaker according to claim 1, wherein the energy consuming element is a resistance element. 4. The DC high-speed vacuum circuit breaker according to claim 1, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 5. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a wiring connected in parallel to the vacuum valve through which direct current flows. A DC high-speed vacuum circuit breaker comprising: an element that consumes energy stored in stray inductance; and a capacitive element connected in parallel near the vacuum valve. 6. The DC high-speed vacuum circuit breaker according to claim 5, wherein the energy consuming element is a nonlinear resistance element. 7. The DC high-speed vacuum circuit breaker according to claim 5, wherein the energy consuming element is a resistance element. 8. The DC high-speed vacuum circuit breaker according to claim 5, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 9. The DC high-speed vacuum circuit breaker according to claim 5, wherein the capacitive element is an element having a larger capacity than the capacity when the vacuum valve is open. 10. The DC high-speed vacuum circuit breaker according to claim 5 or 9, wherein the capacitive element is a capacitor. 11. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and wiring connected in parallel near the vacuum valve and through which direct current flows. DC high speed vacuum circuit breaker with an element that consumes energy stored in the stray inductance of. 12. The DC high-speed vacuum circuit breaker according to claim 11, wherein the energy consuming element is a nonlinear resistance element. 13. The DC high-speed vacuum circuit breaker according to claim 11, wherein the energy consuming element is a resistance element. 14. The DC high-speed vacuum circuit breaker according to claim 11, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 15. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a wiring connected in parallel to the vacuum valve through which direct current flows. an element that consumes energy stored in a stray inductance; and a capacitive element connected in parallel to the vacuum valve; A DC high-speed vacuum circuit breaker in which the loop length of a closed circuit including the capacitive element is shortened. 16. The DC high-speed vacuum circuit breaker according to claim 15, wherein the energy consuming element is a nonlinear resistance element. 17. The DC high-speed vacuum circuit breaker according to claim 15, wherein the energy consuming element is a resistance element. 18. The DC high-speed vacuum circuit breaker according to claim 15, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 19. The DC high-speed vacuum circuit breaker according to claim 15, wherein the capacitive element has a larger capacity than the capacity when the vacuum valve is open. 20. The DC high-speed vacuum circuit breaker according to claim 15 or 19, wherein the capacitive element is a capacitor. 21. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a wiring connected in parallel to the vacuum valve through which direct current flows. and an element that consumes energy stored in stray inductance, and consumes energy stored in the stray inductance of the vacuum valve and the conductive wire by a loop length of a closed circuit including the vacuum valve, the capacitor, and the switching means. A DC high-speed vacuum circuit breaker with a shortened loop length of the closed circuit that contains the elements. 22. The DC high speed vacuum circuit breaker according to claim 21, wherein the energy consuming element is a nonlinear resistance element. 23. The DC high-speed vacuum circuit breaker according to claim 21, wherein the energy consuming element is a resistance element. 24. The DC high-speed vacuum circuit breaker according to claim 21, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 25. In an electric vehicle to which direct current is supplied from an overhead wire and the main motor is operated by a main motor control means, a vacuum valve for cutting off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, An electric vehicle equipped with a DC high speed vacuum circuit breaker, comprising: means for charging a capacitor; and an element connected in parallel to said vacuum valve and consuming energy stored in stray inductances of wiring through which direct current flows. 26. The electric vehicle according to claim 25, wherein the energy consuming element is a DC high-speed vacuum breaker that is a nonlinear resistance element. 27. The electric vehicle according to claim 25, wherein the energy consuming element is a DC high-speed vacuum breaker which is a resistance element. 28. The electric vehicle according to claim 25, wherein the energy consuming element is a DC high-speed vacuum circuit breaker that is a parallel body of a nonlinear resistance element and a resistance element. 29. In an electric vehicle where direct current is supplied from an overhead wire and the main motor is operated by a main motor control means, a vacuum valve for cutting off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, means for charging a capacitor; an element connected in parallel to the vacuum valve to consume energy stored in stray inductance of wiring through which direct current flows; and a capacitive element connected in parallel to the vacuum valve. Electric vehicle equipped with a DC high-speed vacuum circuit breaker. 30. The electric vehicle according to claim 29, wherein the energy consuming element is a DC high-speed vacuum breaker that is a nonlinear resistance element. 31. The electric vehicle according to claim 29, wherein the energy consuming element is a DC high-speed vacuum circuit breaker which is a resistance element. 32. The electric vehicle according to claim 29, wherein the energy consuming element is a DC high-speed vacuum circuit breaker that is a parallel body of a nonlinear resistance element and a resistance element. 33. An electric vehicle equipped with a DC high-speed vacuum breaker according to claim 29, wherein the capacitive element is an element having a larger capacity than the capacity when the vacuum valve is open. 34. An electric vehicle equipped with a DC high-speed vacuum circuit breaker according to claim 29 or 33, wherein the capacitive element is a capacitor. 35. A vacuum valve that cuts off direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a means for charging the capacitor, and a capacitive element connected in parallel to the vacuum valve. A DC high-speed vacuum circuit breaker with a small inductance circuit. 36. The DC high-speed vacuum circuit breaker according to claim 35, wherein the capacitive element is an element that consumes energy stored in stray inductance of wiring through which DC flows. 37. The DC high-speed vacuum circuit breaker according to claim 36, wherein the energy consuming element is a nonlinear resistance element. 38. The DC high-speed vacuum circuit breaker according to claim 35, wherein the circuit having the capacitive element is a parallel circuit of a capacitor and an element that consumes energy stored in stray inductance of wiring through which DC flows. 39. The DC high-speed vacuum circuit breaker according to claim 38, wherein the energy consuming element is a nonlinear resistance element. 40. The DC high speed vacuum circuit breaker according to claim 38, wherein the energy consuming element is a resistive element. 41. The DC high-speed vacuum circuit breaker according to claim 38, wherein the energy consuming element is a parallel body of a nonlinear resistance element and a resistance element. 42. The DC high-speed vacuum circuit breaker according to claim 35, wherein the capacitive element is an element having a larger capacity than the capacity when the vacuum valve is open. 43. In an electric train to which direct current is supplied from an overhead wire and the main motor is operated by a main motor control means, a vacuum valve for cutting off the direct current, a series body of a capacitor and a switching means connected in parallel to the vacuum valve, a closed circuit comprising the vacuum valve, the capacitor and the switching means, comprising means for charging the capacitor and an element connected in parallel to the vacuum valve and consuming energy stored in stray inductance of wiring through which direct current flows; An electric vehicle equipped with a DC high-speed vacuum circuit breaker in which the loop length of a closed circuit including the vacuum valve and an element that consumes energy stored in the stray inductance of the conductive wire is shorter than the loop length of the vacuum valve. 44. The electric vehicle according to claim 43, wherein the energy consuming element is a DC high-speed vacuum breaker that is a nonlinear resistance element. 45. The electric vehicle according to claim 43, wherein the energy consuming element is a DC high-speed vacuum circuit breaker which is a resistance element. 46. The electric vehicle according to claim 43, wherein the energy consuming element is a DC high-speed vacuum circuit breaker that is a parallel body of a nonlinear resistance element and a resistance element. 47. An electric vehicle comprising a DC high-speed vacuum circuit breaker according to claim 43, wherein the capacitive element is an element having a larger capacity than the capacity when the vacuum valve is open. 48. An electric vehicle equipped with a DC high-speed vacuum circuit breaker according to claim 43 or 47, wherein the capacitive element is a capacitor.