JP2842502B2 - Electric car - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle for controlling a time from a command of a driver's cab to a start thereof according to a difference between an overhead line voltage and a filter capacitor voltage.

[0002]

2. Description of the Related Art FIG. 4 shows, for example, "Electric Vehicle Science" (Heisei 4).
FIG. 1 is a circuit diagram showing a configuration of a conventional electric vehicle disclosed in Electric Vehicle Research Group, Inc. In the figure,
1 is a pantograph for inputting power from a DC overhead wire 2, 3
Is a first unit switch connected to the pantograph 1, 4 is a second unit switch connected to the first unit switch 3, 5 is a filter reactor 6 sequentially connected to the second unit switch 4 And an inverted L-type input filter circuit including a filter capacitor 7.

[0003] 8 is a charging resistor connected in parallel with the second unit switch 4, 9 is a discharge resistor connected in parallel with the filter capacitor 7, and 10 is a VVVF inverter device connected in parallel with the filter capacitor 7 , 11 is this V
Drive device connected to the VVF inverter device 10, 12
Is a power line command line, and a power line command signal is introduced when a master controller of a cab (not shown) is operated to the power line position. 13 has one end connected to the power line command line 12 and the other end connected to the ground, and turns the first unit switch 3 ON / OF.
F is the first solenoid valve coil.

[0004] Reference numerals 14 and 15 denote relay contacts and second solenoid valve coils connected in series with the power line command line 12 and in parallel with the first solenoid valve coil 13, and the second solenoid valve coil 15 is a second solenoid valve coil. The second unit switch 4 is turned ON / OFF. 16
Is a relay coil having one end connected to the power line command line 12 and the other end connected to a gate control circuit 19 for controlling the VVVF inverter device 10. When the relay coil 16 is excited, the relay contact 14 is turned on.

A first auxiliary contact 17 has one end connected to the power line 12 and the other end connected to the gate control circuit 19, and is turned on when the first solenoid valve coil 13 is excited.
Is a second auxiliary contact, one end of which is connected to the power command line 12 and the other end of which is connected to the gate control circuit 19, and which is turned on when the second solenoid valve coil 15 is excited. The overhead wire voltage detector 21 is a filter capacitor voltage detector for detecting the voltage of the filter capacitor 7.

Next, the operation of the conventional electric vehicle configured as described above will be described. First, when a command is issued from a cab (not shown), a power command signal is introduced from a power command line 12, and the first solenoid valve coil 13 is excited, the first unit switch 3 and the first The auxiliary contact 17 is turned on. When the first unit switch 3 is turned on, the first unit switch 3 is connected from the overhead line 2 via the pantograph 1.
A current flows through the path of the charging resistor 8, the filter reactor 6, the filter capacitor 7, and the filter capacitor 7 is charged.

At this time, in order to prevent the device from being damaged by the vibration of the input filter circuit 5, it is necessary to charge the filter capacitor 7 so that the voltage of the filter capacitor 7 becomes 90% or more of the steady value. Generally done. On the other hand, when the first auxiliary contact 17 is turned on,
A power command signal is introduced into the gate control circuit 19, and the gate control circuit 19 determines a time required for charging the voltage of the filter capacitor 7 from 0 to 90% of the steady value after receiving the power command signal. After a certain period of time, the relay coil 16 is excited.

Then, when the relay coil 16 is excited, the relay contact 14 is turned on, and the second solenoid valve coil 15 is excited. Then, when the second solenoid valve coil 15 is excited, the second unit switch 4 and the second auxiliary contact 18 are turned on. When the second unit switch 4 is turned on, the charging resistor 8 is short-circuited. On the other hand, when the second auxiliary contact 18 is turned on, a power command signal is introduced into the gate control circuit 19. The gate control circuit 19 confirms that the charging resistor 8 is short-circuited by the power command signal,
The application of the gate pulse to the switching element in the VVVF inverter device 10 is started, and the VVVF inverter device 10 drives the driving device 11 by applying a three-phase alternating current to the induction motor of the driving device 11.

Next, a method for obtaining the time required for charging the voltage of the filter capacitor 7 from 0 to 90% of the steady value, that is, a constant time element will be described. First, the filter capacitor voltage E _FC of filter capacitor 7 is represented by the following formula (1). E _{FC (t)} = E _S (1−e− ^{t / CR} ) (1) where t: the voltage of the filter capacitor 7 is 0 V to E _FC
Time required to charge to V E _S : overhead wire voltage C: filter capacitor capacity R: resistance of charging resistor

The above equation (1) represents the filter capacitor voltage E
_Assuming that the time required for charging the _FC from 0 to 90% of the steady value is t ₁ , it is expressed by the following equation (2). E _S −E _{FC (t1)} = E _S e ^{−t1 / CR} (2) The steady value of the filter capacitor voltage E _FC is the overhead wire voltage E _S (for example, (Rated 1500 V), the following equation (3) holds. E _{FC (t1)} / E _S = 0.9 ∴E _{FC (t1)} = 0.9E _S (3)

[0011] Here, substituting the equation (3) into the equation _{(2), E S -0.9E S} = E S e -t1 / CR 0.1E S = E S e -t1 / CR 0. _{^{1 = e -t1 / CR t 1}} = 2.3CR ·············· (4) , and the steady-state value filter capacitor voltage E _FC is 0-9
The time required to charge the battery to 0%, that is, the constant time element t ₁
Is required.

[0012]

The conventional electric vehicle is constructed as described above, and the time required for the voltage of the filter capacitor 7 to be charged from 0 to 90% of the steady value is defined as a second unit. Since the switch 4 is turned on, for example, when some voltage remains in the filter capacitor 7, even if the voltage reaches 90% of the steady state value before the certain time, if the certain time does not elapse, the switch capacitor 4 is turned on. Even if the second unit switch 4 is not turned on and the command of the driver's cab is issued, the driving device 11 is not driven. Therefore, there is a problem that the time from the command of the driver's cab to the start is wasted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an electric vehicle capable of shortening the time from the command of the driver's cab to the start.

[0014]

An electric vehicle according to the present invention comprises a first switch connected sequentially between a DC overhead wire and the ground.
Switch and a second switch in which a charging resistor is connected in parallel.
, The filter reactor, and the main motor drive circuit are connected in parallel.
Filter capacitor connected to the
And the voltage difference between the two capacitors.
And a closing switch of the second switch according to the voltage difference.
Means for controlling the imaging .

[0015]

The control device for an electric vehicle according to the present invention varies the closing timing of the second switch according to the difference between the overhead line voltage and the filter capacitor voltage.

[0016]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of an electric vehicle according to Embodiment 1 of the present invention. In the figure, the same parts as those in the related art are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 22 is connected to the power line command line 12, and a command device for turning on / off the first unit switch 3. Reference numeral 23 is connected to the command device 22, and inputs both voltage values from both voltage detectors 20 and 21, These voltage differences
A time setting device including means for detecting and a time for turning on the second unit switch 4 in accordance with the voltage difference;
3 and the output side is the same as the conventional device.
Is a timer connected to the solenoid valve coil 15 of FIG.

The operation of the electric vehicle of the first embodiment configured as described above will be described. First, a command is issued from a cab (not shown) as in the conventional case, and
To the command device 22. Then, the command device 22 turns on the first unit switch 3 and gives a command to the time setting device 23. Then, when the first unit switch 3 is turned on, the first unit switch 3 is connected to the charging resistor 8 via the pantograph 1 from the overhead line 2.
A current flows through the path from the filter reactor 6 to the filter capacitor 7, and the filter capacitor 7 is charged.

On the other hand, when the time setting device 23 receives the command, the time of the closing timing of the second unit switch 4 is determined from the difference between the two voltage values detected from the overhead line voltage detector 20 and the filter capacitor voltage detector 21. Ask, timer 24
Is set to the time of this injection timing. After the set time has elapsed, the timer 24 sets the second solenoid valve coil 15
Is excited. When the second solenoid valve coil 15 is excited, the second unit switch 4 is turned on, and the charging resistor 8 is short-circuited. Hereinafter, the same operation is performed through the same circuit as in the related art, and the VVVF inverter device 10 applies a three-phase AC to the induction motor of the driving device 11 to drive the driving device 11.
Drive.

Next, a description will be given of how to determine the set time of the closing timing of the second unit switch 4 in the time setting device 23. First, for example, assuming that the voltage value of the filter capacitor 7 from the filter capacitor voltage detector 21 is x% of the steady value, the time t ₂ required to charge the filter capacitor 7 from 0 to x% of the steady value is calculated by the above equation (3). ), The following equation (5) holds. E _{FC (t2)} = (x / 100) E _S (5) where 0 <x / 100 <0.9

Then, when the above equation (5) is substituted for the difference between the two voltage values from the overhead wire voltage detector 20 and the filter capacitor voltage detector 21, E _S -E _{FC (t2)} = E _S- (x / 100 ) E _S = (1−x / 100) E _S (6) Further, substituting the time t ₂ in the above formula _{(1), E FC (t2} ) = E S (1-e -t2 / CR) E S -E FC (t2) = E S e -t2 / CR · ......... (7)

Then, when the above equation (6) is substituted into the above equation (7) and the time t ₂ is obtained, the following equation (8) is obtained. (1-x / 100) E S = E S e -t2 / CR e -t2 / CR = 1-x / 100 t 2 = -CRln (1-x / 100) ·· (8) where, ln (1 −x / 100) <0

FIG. 2 is a diagram showing the relationship between the difference between the overhead wire voltage E _S and the filter capacitor voltage E _{FC (t)} and the time t. As is clear from this figure, time t ₁ and time t ₂
The difference between this and the time required for charging the filter capacitor 7 to 90% of the steady value when the filter capacitor 7 is charged to x% of the steady value, that is, the set time t of the closing timing of the second unit switch 4
Because it is _3, from the equation (4) and _{(8), t 3 = t} 1 -t 2 = 2.3CR - {- CRln (1-x / 100)} = CR {2.3 + ln (1-x / 100)｝ (9)

[0023] Incidentally, as can be seen from this time 3, the theoretical voltage value 25 when the actual filter capacitor 7 is charged from the point of xE _S ie E _{SC (t2)} has established the following equation (10). _{E FC (T) = E FC} (t2) + (E S -E FC (t2)) (1-e -T / CR) ·· (10) where, T: filter capacitor 7 E _FC of _(t2) in fact, as this time until the E _FC V when have charge time t ₄ when required for the theoretical voltage value 25 of the filter capacitor 7 is charged to 90% x% of steady-state values, the equation (1 ) shorter than the set time t ₃ when required for effective voltage value 26 of the filter capacitor 7 is charged to 90% x% of steady-state value in it, the filter since approximates the set time t _3, the time setting t ₃ It is considered as the time required for the voltage of the capacitor 7 to be charged from x% to 90% of the steady value.

In the electric vehicle of the first embodiment configured as described above, the time setting device 23 determines the set time, that is, the turn-on timing of the second unit switch 4 from the difference between the overhead line voltage and the filter capacitor voltage. Therefore, the set time can be varied in accordance with the voltage remaining in the filter capacitor 7, and the second unit switch 4 can be turned on without wasting time from the command to activation.

[0025]

As described above, according to the present invention, the DC
A first switch sequentially connected between the overhead wire and the ground,
A second switch having a charging resistor connected in parallel;
The luta reactor and the main motor drive circuit are connected in parallel.
Filter capacitor and overhead line voltage and filter capacitor
For detecting the voltage difference between the two voltages
And the closing timing of the second switch according to the voltage difference.
Control means for detecting the voltage of the overhead wire and the voltage of the filter capacitor and controlling the timing of turning on the second switch based on the difference between the two voltages. It is possible to provide an electric vehicle that can reduce the power consumption.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an electric vehicle according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a difference between an overhead wire voltage and a filter capacitor voltage and time.

FIG. 3 is a diagram showing a comparison between a theoretical voltage value and an effective voltage value charged in a filter capacitor and time.

FIG. 4 is a circuit diagram showing a configuration of a conventional electric vehicle.

[Explanation of symbols]

1 pantograph, 2 overhead lines, 3 first unit switch, 4 second unit switch, 5 input filter circuit,
6 filter reactor, 7 filter capacitor, 8
Charge resistor, 9 Discharge resistor, 10 VVVF inverter device, 11 drive device, 12 lines command line, 15
2nd solenoid valve coil, 20 overhead wire voltage detector, 21 filter capacitor voltage detector, 22 command device, 23
Time setting device, 24 timer.

Claims (1)

(57) [Claims] 1. A first switch connected in series between a DC overhead wire and the ground, a second switch connected in parallel with a charging resistor, a filter reactor, and a main motor drive circuit connected in parallel. Connect the connected filter capacitor and the
Detecting the line voltage and the voltage of the filter capacitor
Means for detecting a voltage difference between the two voltages,
Controlling the turn-on timing of the second switch.
An electric car comprising steps .