JP2579910B2 - Electric car control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention drives and controls a plurality of induction motors using a variable voltage / variable frequency inverter device (hereinafter referred to as a VVVF (Variable Voltage Variable Frequency) inverter device). The present invention relates to a control device for an electric vehicle that performs coasting control and re-brake control in an electric vehicle that travels by performing the control.

(Prior Art) FIG. 4 shows an example of a main circuit configuration of an electric vehicle driven and controlled by a VVVF inverter device. In FIG. 4, Pan is a current collector such as a pantograph, L1 and L2 are unit switches, CHR is a charging resistor connected in parallel with the unit switch L2, FL is a filter reactor, R1 is an overcurrent suppression resistor, and DCPT is a DC transformer. , R2 is DCPT series resistance, OVCRF is thyristor for overvoltage control, FC is filter capacitor, INV
Is a VVVF inverter device, GS is a ground switch, IM1 and I
M2 indicates an induction motor.

Next, FIG. 5 shows a timing chart for explaining the main circuit configuration of FIG. 4 and the operation of the conventional electric vehicle control device of FIG.

In FIG. 5, L1 and L2 indicate unit switches, and BRR, P
BR, TR1, and FCR indicate auxiliary relays. On the other hand, in FIG. 6, D1 and D2 are diodes, LAR is an auxiliary relay of the unit switch L2, R1 and R2 are off-state resistors, and C1 and C2 are off-state capacitors. TD is an on-delay timer, CONTACT is a contact of a protection relay, and other elements are the same as those in FIG.

Next, the sequence in the case of the regenerative braking in FIG. 6 will be described first.

Now, when a brake command is issued, the auxiliary relay BRR is turned on in route A. Next, the auxiliary relay PBR is turned on by the route A, and a B command to the logic device is issued. On the other hand, the auxiliary relay TR1 is turned on by the path c. Next, the unit switch L1 is turned on by the path d passing through the contact point of the protection circuit. Next, the unit switch L2 is turned on after the ON delay time of the on-delay timer TD by the route オ. At this time, the auxiliary relay LAR operates at the same time, and the unit switch L2 is self-protected. Next, the path GS presses the GS terminal, which is the gate start command of the logic device, while the operating condition of the auxiliary relay FCR is also satisfied. As described above, the regenerative brake current flows as indicated by the path A in FIG. 4, and the regenerative brake acts on the electric vehicle.

Next, a sequence for releasing the brake will be described.

If the brake is released now, the BRR, PBR and B commands that are pressurized by the route A and the route A in FIG. 6 are not pressurized. Next, the unit switch L1 is turned off at the contact of the auxiliary relay FCR that turns off when the regenerative braking current falls below a certain set value or the auxiliary relay TR1 that has an off-time element, whichever turns off faster. On the other hand, in the section A of FIG. 5, control is performed to attenuate the brake current at a certain reduction rate by software of the microcomputer. Therefore, the auxiliary relay FCR is always turned off. However, there is a limit on the time until the auxiliary relay FCR is turned off, and this limit is the time when the auxiliary relay TR1 is turned off. Thereafter, since the contact of the unit switch L1 of the path is opened, the power of the auxiliary relay FCR is turned off, and the terminal GS which is the gate start command is not pressurized. The unit switch L2 is turned off after an off time determined by the resistor R2 and the capacitor C2. The power of the auxiliary relay FCR is turned off,
In addition, the terminal GS, which is a gate start command, is not pressurized.
As a result, as shown in FIG. 4, the INV-IM 1, 2 system is in a coasting state while being disconnected from the overhead line.

The DC transformer DCPT is connected between its series resistor R2 and OVD
Configure the circuit to filter the electric vehicle
When the voltage of FC is detected and the voltage of this filter capacitor FC exceeds the set value, the overvoltage suppression thyristor OVCRF is turned on and the filter capacitor FC is changed from FC → R1 → O
Discharge is performed on the VCRF path, and the unit switches L1 and L2 are opened to protect the input side of the VVVF inverter INV from being in an overvoltage state. Although the case of the regenerative braking has been described above, the same sequence is applied to the case of the regenerative braking.

By the way, in the conventional control device of the electric vehicle that is driven and controlled by the VVVF inverter device as described above, the re-braking command is issued to the electric vehicle in the coasting state after performing the power off or regenerating the regenerative brake. In this case, since the unit switches L1 and L2 are open during coasting, it takes time to charge the filter capacitor FC after the unit switch L1 is turned on, which slows down the regenerative brake circuit configuration and reduces the responsiveness of the regenerative brake. , And as a result, the power regeneration rate decreases.

(Problems to be Solved by the Invention) As described above, in the conventional control method, since the unit switch is opened during the coasting state, even if a re-brake command is issued, the closing time of the unit switch and the filter capacitor are not changed. Charging time is always required, and it takes time to configure the regenerative brake circuit, and the power regeneration rate is low.

Therefore, the present invention provides a control device for an electric vehicle that can configure a regenerative brake circuit in an extremely short time by eliminating the time for turning on a unit switch and the time for charging a filter capacitor, thereby increasing the power regeneration rate. The purpose is to provide.

[Configuration of the Invention] (Means for Solving the Problems) In order to achieve the above object, according to the present invention, a first switch connected to a current collector for collecting DC power, and the first switch And a parallel circuit in which a charging resistor and a second switch are connected in parallel with each other. The DC power is converted to AC power and connected to the parallel circuit, and the AC power is driven by an electric vehicle. An inverter device for supplying to the electric motor, a filter capacitor connected to an input terminal of the inverter device, an overvoltage suppression circuit connected in parallel with the filter capacitor, and having a resistor and a switch element connected in series; A voltage detector for detecting a voltage between terminals of the filter capacitor; and
Closing the switch to operate the inverter device,
When the inter-terminal voltage detected by the voltage detector exceeds a first set value set in advance, a first element for firing the switch element and opening the first and second switches. Control means, during coasting operation of the electric vehicle, the first and second switches are kept closed to stop the operation of the inverter device, and the terminal-to-terminal voltage detected by the voltage detector is Second control means for opening the first and second switches by igniting the switch element when a second set value which is set to a value higher than the first set value in advance is exceeded; It is a control device for an electric vehicle, comprising:

(Operation) According to the control device for an electric vehicle described above, in the coasting state after turning off the vehicle or releasing the regenerative brake, the first switch and the second switch are opened only by stopping the operation of the inverter device. Since it is only necessary to start the operation of the inverter device at the time of re-braking the electric vehicle, it is not necessary to turn on the unit switch and charge the filter capacitor, thereby shortening the construction time of the regenerative braking circuit. In addition, when the voltage of the filter capacitor becomes equal to or higher than the second set value due to overhead wire voltage fluctuation in a state where the operation of the inverter device is stopped without opening the first switch and the second switch, the switch element is fired. To discharge the charging voltage of the filter capacitor and open the first and second switches, or By opening the first switch when the flowing DC current becomes equal to or greater than the set value, the frequency of operation of the overvoltage protection device due to overhead line voltage fluctuation can be suppressed.

(Embodiment) As shown in the flowchart of FIG. 1, the control device for an electric vehicle according to the present embodiment performs a power off or a regenerative brake release under the condition that the speed of the electric vehicle is higher than the set speed. In the coasting state, the first switch and the second switch are not opened and only the operation of the inverter device is stopped, and when the electric vehicle is braked again, the operation of the inverter device is started to constitute a regenerative braking circuit. ,
Also, an overcurrent suppression circuit formed by connecting a resistor and a switch element such as a thyristor in series is provided in parallel with the filter capacitor, and the operation of the inverter device is stopped without opening the first switch and the second switch. ,
When the voltage of the filter capacitor exceeds a set value, the thyristor is turned on and the first and second switches are opened.

Hereinafter, an embodiment of the present invention based on the above-described concept will be described with reference to the drawings.

FIG. 2 is a timing chart showing the operation of the control device for the electric vehicle shown in FIG. 3, and FIG. 3 shows a configuration example of a control circuit for explaining a specific example of the control device.
5 and 6 are denoted by the same reference numerals and description thereof is omitted, and only different portions will be described here.

In FIG. 3, VLR is an auxiliary relay for detecting the speed of the electric vehicle, which operates in synchronization with the speed signal input to the above-mentioned logic device, and is turned on at a constant speed V ₀ Km / h or more.
BSR is an auxiliary relay that is turned on only when a brake command is issued, and TR2 is an auxiliary relay that constitutes an off-time elementary circuit by combining a resistor R3 and a capacitor C3. D3 to D5 indicate diodes, respectively. On the other hand, the speed signal VSIG input to the logic device is originally required as a control sensor in a VVVF-controlled electric vehicle, and is not particularly required for the present invention. The input terminal of the speed signal VSIG to the logic device is VS, and the input terminal of the auxiliary relay VLR is VL.

Further, in this embodiment, the DC transformer DC shown in FIG.
The set value of the voltage detection by the voltage detector composed of PT and its series resistor R2 is set to be higher than the filter capacitor voltage value during the normal running and regenerative braking of the electric vehicle. In this case, it is necessary to set a two-step set value of the first set value of the normal OVD circuit and the second set value of the OVD circuit during coasting control, but this can be switched by the microcomputer. Like that.

Next, a control device for an electric vehicle according to the present embodiment will be described.

First, a sequence when the speed of the electric vehicle is high and the auxiliary relay VLR is on in FIG. 3 will be described. When the auxiliary relay VLR is off, the sixth
The sequence is exactly the same as the diagram.

In FIG. 3, in the coasting state in which the vehicle is once driven and the vehicle is turned off, as shown in FIG. 2, the unit switches L1, L2, the auxiliary relays BRR, PBR, and TR1 are on and in an initial state. If a brake command is issued in this state, the auxiliary relay BSR operates according to the route A, and
A command is input to the logic device. Next, the auxiliary relay TR2 is turned on by the route A. Further, the condition that the GS terminal of the logic device is pressurized by the route C to start the gate of the VVVF inverter device INV and the auxiliary relay FCR is turned on is also created. As a result, the VVVF inverter INV operates to operate the regenerative brake on the electric vehicle. That is, since the unit switches L1 and L2 have already been turned on and the filter capacitor FC has been charged, the configuration of the regenerative brake circuit is performed quickly, and the action of the regenerative brake is increased.

Next, a sequence for releasing the brake will be described.

If there is no brake command, the auxiliary relay BSR of the route A in FIG. 3 turns off, and at the same time, the B command disappears. At the same time, the coil of the auxiliary relay TR2 on the path A is no longer pressurized, and the auxiliary relay TR2 starts off-delay, and after the time of the auxiliary relay TR2, the auxiliary relay TR2 on the path C
Contacts open and the GS terminal of the logic device becomes non-pressurized, and VVVF
The gate of the inverter INV is stopped, while the auxiliary relay FCR is not applied to the coil, and the auxiliary relay FCR does not operate. Then, during the off-time of the auxiliary relay TR2, that is, in the section A in FIG. 2, control is performed to reduce the brake current to 0 (A) by software of the microcomputer. As a result, the main circuit of the regenerative brake circuit is opened, but when the speed of the electric vehicle is higher than the set value of the auxiliary relay VLR, the unit switches L1 and L2 remain in the on state and remain in the coasting state. Then, the next re-run and re-brake will be prepared.

On the other hand, in the state where the gate of the VVVF inverter INV is stopped without opening the unit switch L and the unit switch L2 in the above, the voltage of the filter capacitor FC is increased during the normal operation of the electric vehicle and during the regenerative braking. When the value becomes higher than the set value, connect this to the DC
The voltage of the filter capacitor FC is discharged by turning on the overvoltage suppression thyristor OVCRF, which is detected by a voltage detector consisting of PT and its series resistor R2.
This prevents the input side of the VVVF inverter INV from becoming overvoltage.

As described above, the control device for the electric vehicle according to the present embodiment provides the unit switch L1 and the unit switch L1 in the coasting state after the power off or the regenerative brake is released under the condition that the speed of the electric vehicle is higher than the set speed. Without opening unit switch L2
The gate of the VVVF inverter INV is stopped before re-braking the electric vehicle.
Of the regenerative braking circuit by starting the gate of the thyristor OV
An overcurrent suppression circuit consisting of a series connection of CRFs is provided in parallel with the filter capacitor FC, and the voltage of the filter capacitor FC is stopped when the operation of the VVVF inverter is stopped without opening the unit switches L1 and L2. When the voltage of the filter capacitor becomes higher than the set value of the filter capacitor voltage during normal operation of the electric car and regenerative braking, the overvoltage suppression thyristor OVCRF is turned on to discharge the voltage of the filter capacitor FC. .

Therefore, the time for turning on the unit switches L1 and L2 and the time for charging the filter capacitor FC are not required, so that the time for forming the regenerative braking circuit at the time of re-braking is remarkably shortened, thereby increasing the re-braking response. As a result, the wear of the brake shoes at high speed is reduced, and thus the power regeneration rate can be increased. Further, in the control device of the present embodiment, the unit switch L1 and the unit switch L2 are not opened during the coasting state after turning off the car or regenerating the regenerative brake under the condition that the speed of the electric car is higher than the set speed. Therefore, the filter capacitor FC is always connected to the overhead wire. For this reason, OVCR
Because the frequency of F operation increases, the setting value of the OVD detection circuit is set higher than the normal power and regenerative brake width values.

It should be noted that the present invention is not limited to the above-described embodiment, but can be implemented in various modifications without departing from the scope of the invention.

[Effects of the Invention] As described above, according to the present invention, it is not necessary to turn on the unit switch and charge the filter capacitor, and the regenerative braking circuit can be configured in an extremely short time to increase the power regeneration rate. It is possible to provide an electric vehicle control device capable of reliably protecting the inverter device from overvoltage.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control device for an electric vehicle according to the present invention, FIG. 2 is a timing chart for explaining the control device for an electric vehicle according to the present invention, and FIG. 3 is a diagram for realizing the control device. FIG. 4 is a control circuit diagram, FIG. 4 is a main circuit configuration diagram of an electric vehicle driven and controlled by a VVVF inverter device, FIG. 5 is a timing chart for explaining a conventional electric vehicle control device, and FIG. It is a control circuit diagram for realizing a control device. Pan… Pantograph, L1, L2… Unit switch, CHR…
... Charging resistor, FL ... Filter reactor, R1 ... Overcurrent suppression resistor, R2 ... DC transformer series resistor, OVCRF ... Overvoltage suppression thyristor, DCPT ... DC transformer, FC ... Filter capacitor, INV …… VVVF inverter device, GS…
… Ground switch, IM1, IM2 …… Induction motor, BRR, PBR, TR
1, FCR …… Auxiliary relay, D1, D2 …… Diode, LAR ……
Auxiliary relay, R1, R2: Off-state resistance, C1, C2: Off-state capacitor, TD1: On-delay timer, CONTACT: Protection relay contact, B, FCP, GS: Logic Input terminal of device, BSR, TR2 …… Auxiliary relay, VLR, BSR, TR2
…… Auxiliary relay, R3 …… Resistance for element when off, C3 …… Capacitor for element when off, D3 to D5 …… Diode, VSIG ……
Speed signal, VS, VL …… Input terminals of logic device.

Claims (1)

(57) [Claims] A first switch connected to a current collector for collecting DC power; a first switch connected in series to the first switch; and a charging resistor and a second switch connected in parallel. A parallel circuit, an inverter connected to the parallel circuit, converting the DC power to AC power, and supplying the AC power to the electric vehicle driving motor; and a filter capacitor connected to an input terminal of the inverter. An overvoltage suppression circuit connected in parallel to the filter capacitor and having a resistor and a switch element connected in series; a voltage detector for detecting a voltage between the terminals of the filter capacitor; In some cases, the first and second switches are closed to operate the inverter device, and the terminal-to-terminal voltage detected by the voltage detector is set to a first preset voltage. First control means for igniting the switch element to open the first and second switches when the set value is exceeded, and for the coasting operation of the electric vehicle, the first and second switches A second set value at which the operation of the inverter device is stopped by continuing the closed state, and the inter-terminal voltage detected by the voltage detector is set to a value higher than the first set value in advance. And a second control means for opening the first and second switches by igniting the switch element when the distance exceeds the limit.