JPH03251005A - Line breaker for vehicle - Google Patents

Abstract

PURPOSE:To prevent fault current from spreading by containing a line breaker for interrupting main circuit DC current of an electric vehicle and a high speed vacuum circuit breaker in separate boxes. CONSTITUTION:Main circuit DC current is taken in from a stringing 1 through a current collector 2 and fed through line breakers 3a, 3b, contained in a double insulation line breaker box 14, into a circuit breaker box 15a secure directly to the body 8 by means of fixing metals 16. The DC current is fed through a DC high speed vacuum circuit breaker 15, contained in the circuit breaker box 15a, and a filter reactor 5 to an inverter 6 where it is inverted into VVVF three-phase current for driving an induction motor 7. The current then flows through the body 8 and wheels 9 into a rail 10 and fed back to a substation (now shown). Consequently, no arc is produced even upon interruption of main circuit current and fault current is prevented from spreading.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an on-vehicle type current breaker that suppresses the expansion of fault current in the event of a failure in a protective cut-off system for an electric vehicle.

[Conventional technology]

Conventional current interrupters have a structure in which the entire current interrupter box is insulated with double insulators and mounted on an electric vehicle, as described in Japanese Utility Model Application No. 61-65640.

This will be briefly explained using FIG. 7.

The main circuit current is 1. Current interrupter storage box 1 via current collector 2
Enter 2. The line breaker 3a is installed in the line breaker storage box 12.
, 3b, and a high-speed circuit breaker 4 are arranged in series, and the main circuit current that has passed through the circuit breaker storage box 12 reaches the control device box 6 via the filter reactor 5. The main motor 7 is driven by the control current from the control device box 6, and the main motor 7 is driven by the control current from the control device box 6. It flows through the axle 9 to the rail 10 and returns to the substation (not shown).

By the way, since the line breakers 3a, 3b and the high-speed circuit breaker 4 are both air circuit breakers, arcs fly when the current is interrupted. Even if this arc causes a ground fault in the current interrupter storage box 12, it is insulated from the vehicle body 8 by the insulator 11, so it will not cause a grounding accident, and the configuration will not trip the circuit breaker in the substation (not shown). It has become.

[Problem to be solved by the invention]

Next, using FIG. 8, line breaker 3a.

3b, the structure of an air circuit breaker such as the high speed circuit breaker 4 will be briefly explained.

The figure shows the circuit breaker currently open.

Cylinder 20. Piston dedication 23. The piston is constituted by the packing 21, and the piston support 23 is upward (solid arrow)
When pushed up, the movable contact 25 along with the insulating joint 24
a. The interlocking arm 31 is pushed up. Then, the movable contact 25. The fixed contactor 25 makes contact and the main circuit current flows through the flexible conductor 33. The mechanism that informs the control unit whether or not the contacts are currently in contact with each other is the cam 30. Cam switch 27. Fixed contact base metal 29. Movable contact spring 34 and terminal 2
It is composed of 8. The cam 30 moves upward together with the interlocking arm 31 (in the direction of the solid arrow).

The cam switch 27 operates and the movable contact spring 34 opens. This state is taken out as an output at terminal 28. The control power supply connected to this terminal is 100V, 24V, or 15V DC, which is much lower than the main circuit voltage.
etc. are used.

When the contacts 25, 26 are separated and the current is cut off, a portion of the arc flows into the current interrupter storage box 12, and the exposed movable contact spring 34. Terminal 28 and fixed contact base metal 2
Jump to 9. This is because the control voltage is extremely low. Further, although the cam switch 10 is provided with a cover 32, ionized air easily enters, and when the potential difference with the current interrupter storage box 12 becomes large, insulation breakdown occurs and an arc is generated again in the exposed area. ground fault.

The control power supply line connected to the terminal 28 is bundled together with a plurality of other control lead-through lines and tangentially connected to the control equipment box. Under these conditions, if arc current flows,
A large induced current flows not only to the equipment connected to the control power supply line but also to other control feed-through lines, destroying the equipment connected to it, such as the master controller and inverter control equipment. Put it away.

Incidentally, it is possible to strengthen the insulation of these power supply lines so that they do not come into contact with each other in the event of a ground fault in the storage box, but it is difficult to strengthen the insulation of the exposed portions.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a configuration that does not destroy the control section of an electric vehicle even if an arc causes a ground fault in the current interrupter storage box.

[Means to solve the problem]

In order to achieve the above object, the air-type high-speed circuit breaker is a high-speed vacuum circuit breaker that does not allow arc to leak into the air, and is achieved by housing the circuit breaker on a separate surface from the line breaker.

[Effect]

The case where a large current at the time of an accident is interrupted by a series body of three air circuit breakers will be explained using FIG. 7.

1. Upon receiving the trip signal, the high-speed circuit breaker 4 opens, and the fault current is shunted to a resistor (not shown) connected in parallel to the high-speed circuit breaker 4 and an arc current.

2. When the fault current is reduced by the resistor, open the line breakers 3a, 3b. This interrupts the fault current accompanied by the arc.

As mentioned above, if the high-speed circuit breaker is a high-speed vacuum circuit breaker, the arc will not be emitted into the air, so the secondary arc will not fly from this part to the exposed part. However, even with a high-speed vacuum circuit breaker, the fault current does not completely disappear, and a current due to non-linear resistance, which will be described later, flows, and is interrupted by the line breakers 3a and 3b. Although this current is small compared to the current flowing through the resistor, arcing may occur when the line breaker turns off this current. At this time, there remains a possibility that a ground fault may occur in various control lines connected to the high-speed vacuum circuit breaker. This is solved by placing the line breaker and high speed vacuum circuit breaker in separate locations.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The main circuit DC current is taken from the overhead wire 1 via the current collector 2 and enters the line breaker box 14. Line breaker 3
The main circuit DC current that has passed through a and 3b is transferred to the circuit breaker box 15a.
It is outputted internally through a DC high-speed vacuum circuit breaker 15, and is outputted through a filter reactor 5 to an inverter device 6.
The current is input into a three-phase alternating current with a variable voltage and a variable frequency, and drives the induction motor 7. Furthermore, the car body 8. It flows into the rail 10 via the axle 7 and returns to the substation (not shown).

The circuit breaker box 15a of the DC high-speed vacuum circuit breaker 15 is directly attached to the vehicle body 8 using a fixture 16. This is because the DC high-speed vacuum circuit breaker 15 does not need to be lifted from the vehicle body 8 because it basically does not emit an arc. in this case,
It is desirable that the line breaker 14 has a double insulation structure, and the breaker box 15a is not necessary.

According to this embodiment, since there is no arc discharge to the circuit breaker box 15a, there is no need to strengthen the insulation of various control lines.

Next, the DC high speed vacuum circuit breaker 15 will be 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.

If the commutation frequency of this commutation circuit is increased, the capacitor
Although both the inductance and the inductance can be reduced, there is a limit to the maximum value of the commutation frequency, and it was thought that this would be impossible to achieve (IKHz is the limit).

Therefore, the inventor of the present invention conducted an experiment and obtained the following results.

Current voltage 1600 (V), set value 2080 (A)
, it was proven that the commutation frequency can be cut off at 11.1 (KHz). The commutation frequency is about 10
It's double. 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 no matter how short the wiring is.
(μH) remains, so the commutation frequency is approximately 30 (K
Hz)-40 (KHz) is the limit.

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

Next, explanation will be given using FIG. 2.

The main current from the DC type 'rA1 reaches the load 6 via the vacuum valve 50 and the static overcurrent trip device 57. A series body of a commutating capacitor 54 and a commutating switch 56 serving as an opening/closing means is connected in parallel between the poles of the vacuum valve 5o. In addition, in a separate loop from the commutation capacitor 54 etc.,
A zinc oxide nonlinear resistor 52 is connected in parallel with the vacuum valve 50 . The stray inductance of this closed circuit is smaller than that of the closed circuit consisting of the commutating capacitor 54 and the like. In other words, the wiring length of the closed circuit composed of the zinc oxide nonlinear resistor 52 and the vacuum valve 50 is shorter.

Although not shown in the main figure, a charging circuit is connected to both ends of the commutating capacitor 54.

The vacuum valve 50 operates when the static overcurrent drawing device 57 detects an abnormal current.

The operating principle will be explained below with reference to FIG.

FIG. 3(a) depicts the main current flowing through the vacuum valve 50 which is closed.

Furthermore, the commutating capacitor 54 is charged in the direction shown. When an open command is issued due to a failure condition, first, (b)
The vacuum valve 50 is opened as shown in FIG. Even after opening, the main current continues to flow in the form of an arc in the vacuum. Next, a ◯N command is issued to the current switch 56 and it closes as shown in (c). At that moment, the charge charged in the commutating capacitor 54 is transferred in the opposite direction to the main current because a closed circuit is formed: commutating capacitor 54 → stray inductance 55 → commutating switch 56 → vacuum valve 5o → commutating capacitor 54. begins to flow as an oscillating current. Eventually, when the current in the vacuum bulb 50 becomes near zero (several amperes), the arc is extinguished. However, 2. Normally, even if the arc is extinguished, there is a residual current (current that was flowing through the vacuum valve VI as an arc), and at the moment the arc extinguishes, a peak voltage (dv/dt) is generated across the vacuum valve 50. is applied to it, causing it to ignite again. In this embodiment, the wiring length of the zinc oxide nonlinear resistor 52 is made shorter than the wiring length of the commutation circuit, so that the inductance is reduced. Therefore, with respect to a changing current, the current flows more easily to the zinc oxide non-direct resistor 52 than when the inductance is large.

The zinc oxide nonlinear resistance 52 has a capacitance, and its size is approximately 2.000 times the capacitance when the vacuum valve 50 is open.

Based on the above, the phenomenon of preventing arc re-ignition of the vacuum valve 50 will be explained.

The residual current at the moment the arc is extinguished flows toward the capacity where it flows most easily. In this case, it is a zinc oxide nonlinear resistance 52. Therefore, it is possible to prevent a peak voltage from being applied to the vacuum bulb 50 and to prevent 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.

In addition, it is said that the peak of the commutation current (2) 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 6,000 KW and the DC power supply voltage of about 600 to 3,000 V, the magnitude of the commutating power source Ip is preferably 5,000 (A) or more.

As a result, the arc is completely extinguished and the main current charges the commutating capacitor 54 (FIG. 3(d)).

The constant voltage of the zinc oxide nonlinear resistor 52 is selected to be larger than the power supply voltage E, so that the voltage of the commutating capacitor 54 does not rise and e
), opening the current switch 56 dissipates the energy stored in the inductance of the main circuit. In this case, the zinc oxide nonlinear resistor 52 operates as a resistor.

Next, the case where the DC high-speed vacuum circuit breaker is used in an electric vehicle as described above will be explained using FIG. 3.

Normally, the DC high-speed vacuum circuit breaker 15 is in a closed state. Next, the pantograph 2 is brought into contact with the overhead wire 1, and the line breakers 3a and 3c are turned on. A filter capacitor FC with a large capacity is charged via a charging resistor CHRe. After charging is completed, the line breaker 3b is turned on and the system 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 the line breakers 3a and 3b to shut off the power. 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 (hereinafter referred to as the control unit) inside the DC high-speed vacuum circuit breaker 15, the control unit sends a trip command to the repulsion coil 1, and the repulsion force causes the vacuum valve 50 to close. 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 56.

Then, a commutating current flows from the pre-charged commutating capacitor 54, and the interruption is completed as described above. When the interruption is completed, the main current becomes zero, so the control section issues an LB off command to open the line breakers 3a and 3b.

When the accident has been resolved, the driver presses the reset button switch 1 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 50 is closed. Next, a charging current is applied to charge the commutation capacitor 54 to a predetermined value, and the DC high-speed vacuum circuit breaker 15 enters a standby state.

Regarding the experimental content and detailed explanation of the above-mentioned new DC high-speed vacuum circuit breaker, please refer to the patent application No.
Please refer to No. 201178 (filed on August 4, 1999) for details.

Next, other embodiments of the present invention will be described.

As described above, external trip commands and the like for the DC high-speed vacuum circuit breaker are given by the inverter control device. Therefore, as shown in FIG. 4, a DC high-speed vacuum circuit breaker 12 is integrally housed in the inverter control device box 6. In this case, the wiring length of the trip command line from the inverter control device 6a is shortened, making it easier to interface. Therefore, according to this embodiment, this is due to the induction failure and the like. DC high speed vacuum circuit breaker 1
The probability that the second control section malfunctions is extremely small.

By the way, if this continues, the protection of the filter reactor 5, which is one of the objects to be protected on the overhead line 1 side of the DC high-speed vacuum circuit breaker 12, will be incomplete. This is because the filter reactor 5 is located closer to the power source than the DC high-speed vacuum circuit breaker 12 .

Based on past experience, there have been no accidents involving the axle when it touches the ground, but it is necessary to protect it in case it does happen.

Another embodiment shown in FIG. 5 solves this drawback.

That is, the filter reactor 5 is arranged on the load side of the DC high-speed vacuum circuit breaker 12 and is housed integrally in the inverter control box 6.

This configuration not only provides a clean appearance but also increases protection coverage.

In the above embodiment, a control device using an inverter is used, but it can also be used for chopper or camshaft control without any problem.

〔Effect of the invention〕

According to the present invention, since the high-speed circuit breaker section is arc-free, the storage box can have a non-double insulation structure, which prevents the substation circuit breaker from tripping unnecessarily and causing damage to other trains on the same line. Since there is no need to stop the service due to a power outage, service can be improved. Furthermore, the control wires can function satisfactorily with ordinary level insulated wires.

Further, there is no need to extend the wiring of the information command line for the interface with the inverter device, which is advantageous both in terms of trouble and economy.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a DC high-speed vacuum circuit breaker applied to the present invention, FIG. 3 is an explanatory diagram of the operation of the DC high-speed vacuum circuit breaker, and FIG. 4 is a main wiring diagram when using a DC high-speed vacuum circuit breaker in an electric vehicle, FIG. 5 is a diagram showing another embodiment of the present invention, and FIG. 6 is a diagram showing another embodiment of the present invention. FIG. 7 is a diagram for explaining the prior art, and FIG. 8 is a diagram for explaining an air circuit breaker. 3a, 3b... Line breaker, 5... Filter reactor, 6... Inverter control device box, 15. DC high speed vacuum breaker. Figure 1 Main circuit configuration Figure Figure 7 Figure

Claims (1)

[Claims] 1. In an electric vehicle that interrupts main circuit current using a line breaker and a high-speed circuit breaker, the high-speed circuit breaker is a high-speed vacuum circuit breaker, and the line breaker storage box and Vehicle cut-off path installed in a separate box. 2. A box containing a motor control device for driving an electric vehicle, and a line breaker and a high-speed circuit breaker installed in the electric vehicle to interrupt the main circuit current, wherein the high-speed circuit breaker is connected to a high-speed vacuum A circuit breaker for a vehicle, which is a circuit breaker, and the high-speed vacuum circuit breaker is housed in an integrated box with the electric vehicle drive motor control device. 3. A box that houses an electric motor control device for driving an electric car, a line breaker and high-speed circuit breaker installed in this electric car to interrupt the main circuit current, and a filter reactor installed in this electric car. The current circuit breaker for a vehicle, wherein the high-speed circuit breaker is a high-speed vacuum circuit breaker, and the filter reactor, the high-speed vacuum circuit breaker, and the electric vehicle drive motor control device are housed in an integrated box.