JPS60234403A - Controller for electric railcar - Google Patents

Abstract

PURPOSE:To prevent a switching element from a large defect due to an erroneous firing by connecting resistors between field choppers of a bridge circuit of four sets of switching elements and a power source. CONSTITUTION:The voltage of an armature 3 of a DC motor is controlled by an armature chopper 1. On the other hand, the current of a field 4 is controlled by a field chopper 2 of bridge circuit of switchig elements 21-24 in response to the forward or backward, power or regenerative drive command. A current reducing resistor 12 is normally shortcircuited at both ends by a high speed breaker 8, but connected in series with the chopper 2. Thus, even if the chopper 2 is shortcircuited, the shortcircuiting current is suppressed, and there is accordingly no possibility of inducting a large defect.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an electric vehicle control device, and is particularly suitable for an electric vehicle that performs power running and electric brake control by chopper controlling the field of a DC motor. This invention relates to a control device.

[Background of the invention]

As an electric car control system using a chopper, published in Japanese Patent Publication No. 5'9
As described in Japanese Patent No. 63902, it is known that an armature chopper and a field chopper are arranged side by side.

By the way, in order to perform the forward and regenerative braking without switching the main circuit during the forward and backward movement of the vehicle, it is desirable to switch the excitation direction of the field using a switching element.

For this reason, it is conceivable to configure a bridge circuit as a field chopper, which is composed of four sets of switching elements in which a field is connected to a bridge portion.

However, in this case, if the switching element turns on erroneously, a short circuit may occur in the power supply, which may lead to a serious accident.

[Purpose of the invention]

An object of the present invention is to enable continuous control of forward and backward movement and regeneration in an electric vehicle equipped with a field chopper without switching the υ main circuit using a reverser, etc. To provide an electric vehicle control device that can prevent the risk of a major accident even if a problem occurs.

[Summary of the invention]

The present invention is characterized by providing a field chopper consisting of a bridge circuit of four sets of switching elements in which a field is connected to a bridge section, and a resistor permanently connected between this chopper and a power source. It is.

According to a preferred embodiment of the present invention, a circuit breaker having a current reducing resistor connected in parallel is provided at the receiving end of the electric vehicle, and the receiving end of the field chopper is connected to the center tap of the current reducing resistor.

As a result, power and regeneration control can be performed virtually without contact when the electric vehicle moves forward or backward, and there is no risk of causing a major accident even if the switching elements that make up the field chopper accidentally fire. can be eliminated.

[Embodiments of the invention]

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Figure 1 has an armature chopper 1 and a field chopper 2,
The main (armature) chopper l controls the voltage of armature 3 of the DC motor.
By controlling the current of the field 4 with the field chopper 2, frost control, wind wheel power flow control, and regenerative brake control are performed.

When in operation, the filter capacitor 9 is pressurized through the bank graph 5, the current breaker 6, the filter reactor 7, and the high-speed breaker 8, and the filter capacitor 9 is used as a power source.
Flow interrupter 10. Armature current IM flows through the path of armature 3 and main chopper 1. During the off-period of the main F-jopper 1, the armature current IN
is refluxed.

On the other hand, in the case of forward movement, for example, the field circuit connects the filter capacitor 9 to the first switching element 21 of the field chopper 2, the field 4, and the first switching element of the field chopper 2 via the current reducing resistor 12. A field current IF flows through the path of the second switching element 22. One of these switching elements 21 and 22 must have a self-extinguishing function, and preferably GTOs are used for both of them. Now, when these are turned off, the field current IF is fed back via the freewheeling diodes 241, 231 and the resistor 12 to the filter capacitor 9 connected to the power supply. Note that field control is possible even if the switching element (chopper unit) 21 is always kept in a conductive state and only the switching element (chopper unit) 22 is subjected to chopping control. In this case, the field current flows back through the freewheel diode 231 and the switching element 21.

During regenerative braking, the current interrupter 1o of the circuit is kept open, and the switching elements 23 and 24 of the field chopper 2 are controlled to excite the field 4 to the opposite polarity. Field 4
is excited with opposite polarity, the armature current IM flows through the chopper 11 and the high speed breaker 13 during the period when the main chopper 1 is on.
, through the diode 11, and during the off period, under the action of the internal inductance of the armature 3, a current flows through the freewheeling diode 14 to the filter capacitor 9, which is the power source. A regenerative current flows from the filter capacitor 9 to the overhead wire 15 via the pantograph 5, and a regenerative brake is applied to the electric vehicle.

If there is no other force on the overhead line 15 side that absorbs the regenerated power, the regenerative current may flow to the overhead line side, and the filter capacitor 9 will be overcharged, resulting in an overvoltage. Voltage Vcy of filter capacitor 9 is detected by voltage detector 16 and compared with limit voltage signal Vt in comparator 17. If the capacitor voltage signal Vcy exceeds the limit voltage signal Vt, the comparator 17 fires the overvoltage suppression thyristor 18, so that the resistor 19 absorbs the overvoltage.

The above is the operation during forward power running and forward regeneration, but during reverse power running, the switching elements (chopper unit) 23 and 24 in the field chopper 2 are controlled, and during reverse regeneration, the switching elements 23 and 24 in the field chopper 2 are controlled. By controlling the switching elements 21 and 22, continuous control is possible in combination with the control of the main chopper 1.

For these controls, an armature chopper control device 30,
A field chopper control device 3''1 is provided, which outputs an on/off command signal a+fI'' which outputs a logic signal ``1°'' when turning on the corresponding chopper (chopper unit) and a logic signal ``0'' when turning it off. The gate drive circuits 32, 331 to 334 generate the logic signal ""4.
An ignition signal is given when the value is 1'', and an extinguishing signal is given when the value is 0°', to the chopper 1 and the unit choppers (switching elements) 21 to 24, which are configured of, for example, a GTO.

Compared to chopper control devices that use DC series-wound motors that have been commonly used in the past, this system uses mechanical contacts in the armature and field magnets to switch the electric vehicle's forward and backward movement, power running, and brake. No switching device required υ,
A major feature is that it can be made largely contactless.

Now, the current reducing resistor 12 is provided to open the high-speed cutoff S8 in the event of an overcurrent failure such as grounding on the load side, to reduce the overcurrent once, and to finally cut it off with the current breaker 6. A resistor is commonly used as a protective device for electric cars.

Normally, both ends of the current reducing resistor 12 are short-circuited to the high-speed breaker 8, but for the field chopper 2,
Since they are connected in series, even if a short circuit occurs in the field chopper 2, there is an effect of suppressing the short circuit current. The flow reducing resistance 12 is
The resistance value is usually on the order of several ohms, and the resistance value required for protecting the field chopper 2 is also on the order of several ohms, so it is possible to use both in common.

The intermediate tap Q does not necessarily need to be provided at a point that divides the resistance value of the current reducing resistor 12 into two; by shifting it from the midpoint, a resistance value suitable for protecting the field chopper 2 can be set.

- To give an example, 5 ohms are required as the current reducing resistor 12, which protects the power supply from short circuit caused by the field chopper 2 under normal conditions,
High speed breaker 8 causes υ100 min. Good skin, 4 to 1 resistance 121 ma 4-, f? 2 to J-.

Alternatively, if the resistance value is insufficient with only the current reducing resistor 12, a resistance element can be inserted between the power receiving terminal P of the field chopper 2 and the intermediate tap Q of the current reducing resistor 12. Even with this method, most of the resistance values are reduced current resistance 1
2 can be used, so there is no need to substantially increase the size of the resistor.

FIG. 2 shows another embodiment of the invention. In this embodiment, the series body of the overvoltage suppressing thyristor 18 and the resistor 19 used in the conventional example shown in FIG. 1 is omitted, and an overvoltage suppressing resistor 191 is inserted between the terminals 2 to 9. Of course, the resistor 191 is set so that the combined resistance including the current reducing resistor 12 has a resistance value necessary for suppressing overvoltage.

Also in this embodiment, during normal control, the unit choppers (switching elements) 21 to 24 in the armature chopper 1 and the field chopper 2 are controlled in the same way as in the previous embodiment.

However, when the voltage of the filter capacitor 9 is Vcy, the "'1" output of the comparator 17 causes the gate drive circuits 331 to 331 to
334 is given the "l" signal and all unit choppers 2
1 to 24 are turned on.

Therefore, the voltage of the filter capacitor 9 is discharged through the filter capacitor 9, the current reducing resistor 12, the additional resistor 191 for overvoltage absorption, and the field chopper 2, and the overvoltage is absorbed. Thereafter, the main circuit is opened by the high speed breaker 8 and the current breaker 6.

In this way, the overvoltage suppression thyristor can be omitted, and the field chopper 2 can have this function.

Of course, at the time of overvoltage, only one of the unit choppers 21 and 24 or 23 and 22 connected in series may be turned on.

〔Effect of the invention〕

According to the present invention, it is possible to control both forward and reverse movement and regeneration of an electric vehicle in a non-contact manner, and even if a switching element constituting a field chopper is ignited incorrectly, there is no risk of causing a major accident. You can force it.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an electric vehicle control device showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of an electric vehicle control device showing another embodiment of the present invention. 1... Armature chopper, 2... Field chopper, 21
~24... Unit chopper (switching element), 3.
... Armature of DC motor, 4... Same field, 8... High speed circuit breaker, 12... Current reducing resistor, 16... Receiving end voltage detector, 17... Voltage comparison Vessel, 331-334・
...Gate drive circuit, 341-344...OR gate. Agent Patent Attorney Akio Takahashi No. 1 I ¥1 Figure 2 ~ tS

Claims (1)

[Claims] 1. A DC motor, a chopper device that excites the field of the DC motor in forward and reverse directions independently of its armature, and a current reducing resistor inserted into the main circuit of the DC motor. In an electric vehicle equipped with a circuit breaker in which circuit breakers are connected in parallel, the chopper device is configured with four sets of switching means in which the field is connected to a bridge section, and a permanent connection is provided between the chopper device and the power source. An electric vehicle control device comprising a connected resistor. 2. The permanently connected resistor is the first resistor connected to the current reducing resistor.
Electric vehicle control device described in Section 1. 3. The electric vehicle control device according to item 2, wherein the power receiving terminal of the chopper device is connected to the center tap of the current reducing resistor. 4. The electric vehicle control device according to item 1, wherein the armature of the DC motor is connected in series with a second chopper device. 5. A DC motor, a chopper device that excites the field of this DC motor in both forward and reverse directions independently of its armature, and a cutoff device that is inserted into the main circuit of the DC motor and connected in parallel with a current reducing resistor. In the electric vehicle equipped with a chopper device, the chopper device is constituted by four sets of switching means connecting the field to a bridge portion, and a resistor permanently connected between the chopper device and the power source. , an electric vehicle control characterized by providing means for conducting two sets of switching means in series among the four sets of switching means in response to the receiving end voltage of the electric vehicle exceeding a predetermined value; Device. 6. The electric vehicle control device according to the item 1, wherein one of the DC motors is connected in series with a second chopper left device.