JPH0223044Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an electric vehicle, and more particularly to a control device for an electric vehicle that can charge a storage battery while driving, for example.

Conventionally, there have been electric vehicles that are equipped with a storage battery and an electric motor, and are driven by rotating the electric motor using the storage battery. This kind of electric car is
If the electric power stored in the storage battery is lost, the electric motor will no longer be able to drive the vehicle, so it was necessary to charge the storage battery before the electric power in the storage battery was lost. Normally, such charging was performed using a stationary charging device.

Conventionally, electric vehicles have been put into practical use that can be charged not only as described above but also while the vehicle is running. In such electric vehicles, when braking or going down a slope, the rotation of the wheels is transmitted to the electric motor, the electric motor functions as a generator, and the generated output is used to charge the storage battery.

By the way, when generating electricity while the vehicle is running as described above, the storage battery can be charged because the rotational speed of the electric motor is high and the generated voltage is high while the vehicle is running at a high speed. However, as the speed of the vehicle decreases, the rotation speed of the electric motor decreases.
Eventually, the generated voltage becomes lower than the battery voltage of the storage battery. In such a case, the storage battery cannot be charged. Therefore, conventional electric vehicles have had the disadvantage that the storage battery cannot be charged if the vehicle's traveling speed becomes slower than a certain constant speed.

By the way, there has been an electric vehicle equipped with a DC motor having a shunt field winding as a driving motor. In such an electric vehicle, when a DC motor is used as a generator, the generated voltage can be increased by increasing the field current flowing through the shunt field winding to strengthen the magnetic flux. Therefore, in order to eliminate the above-mentioned drawbacks, it is conceivable to make the field current extremely large during charging while the vehicle is running. However, in order to flow a large field current and strengthen the magnetic flux, it is necessary to increase the field capacity. In order to increase the capacity, the size of the yoke of the DC motor must be increased. Therefore, a new problem arises in that the DC motor becomes larger. Another problem is that the DC motor becomes expensive.

Therefore, the main purpose of this invention is to provide a simple and inexpensive control device for an electric vehicle that can charge the storage battery even at relatively slow running speeds.

In summary, when a DC motor is used as a generator for charging an electric vehicle while it is running, the current based on the generated voltage is controlled intermittently by a chopper control circuit, and this intermittent controlled current is The voltage is boosted by a charging transformer and then rectified.
The battery is charged by supplying it to the storage battery.

The above objects and other objects and features of the present invention will become more apparent from the following detailed description with reference to the drawings.

FIG. 1 is a circuit diagram of a control device for an electric vehicle according to an embodiment of this invention. In the configuration, storage battery 1
The armature current control circuit includes a main switch 2, a shunt resistor 3, an armature 4a of a DC motor (hereinafter referred to as a motor), a reactor winding 5a, and a large-capacity transistor 6, which is an example of a chopper, connected in series. Connected. Note that a fuse 7 may be inserted in the armature current control circuit as necessary.
The main switch 2 is closed when an accelerator pedal (not shown) is depressed, and opened when it is released. The reactor 5a also serves as the secondary winding of the transformer 5. The transformer 5 has two reactor windings 5a.
A primary winding 5 magnetically coupled to it as a secondary winding
Contains b. A pulsed control signal is applied to the gate of the transistor 6. The transistor 6 is turned on and off by this control signal, and the current flowing through the armature 4a is controlled intermittently.

Four rectifying diodes 8 to 11 are connected in connection with the armature current control circuit described above. The diode 8 has its anode connected to the connection point between the main switch 2 and the shunt resistor 3, and its cathode connected to the connection point between the main switch 2 and the fuse 7. The diode 9 has its anode connected to the emitter of the transistor 6 via the fuse 12, and its cathode connected to the connection point between the main switch 2 and the shunt resistor 3. Diode 10 has an anode connected to diode 9 and fuse 1.
2, and its cathode is connected to the anode of diode 11. diode 1
The cathode 1 is connected to the connection point between the main switch 2 and the fuse 7.

Both ends of the primary winding 5b of the transformer 5 described above are connected to a terminal 16a and a terminal 16b, respectively.
During charging, an AC power source from a stationary charging device (not shown) is connected to these terminals 16a and 16b. Further, both ends of the primary winding 5b are connected to switches 17a and 17b, respectively. The diode 18 has its anode connected to one end of the primary winding 5b via the switch 17a, and its cathode connected to the connection point between the main switch 2 and the fuse 7 via the rectifying coil 20.

Further, a field current control circuit is connected between the connection point between the main switch 2 and the fuse 7 and the negative side of the storage battery 1. This field current control circuit is
a switch 21 for switching the polarity of the field current;
A shunt resistor 23, a field winding 24, a switch 25 for switching the polarity of the field current, and a transistor 26 are connected in series, and the switch 21 and the resistor 22 are connected in series.
, shunt resistor 23, field winding 24, and switch 2
A freewheeling diode 27 is connected in parallel to the series circuit with the transistor 5, and a diode 28 is connected in parallel to the transistor 26.
Note that the switch 21 has a common contact 21a connected to the connection point between the main switch 2 and the fuse 7.
and a switching contact 21 connected to a shunt resistor 23
b and a switching contact 21c. Further, the switch 25 has a common contact 25a connected to the collector of the transistor 26, a switching contact 25b connected to the field winding 24 and the above-mentioned switching contact 21c, and a switching contact 25c connected to the above-mentioned switching contact 21b.
including.

In addition, switches 17a, 17b, 21 and 2
5 may be switched manually, or may be switched depending on the traveling speed or the voltage generated by the motor. When switching according to traveling speed or motor generated voltage,
A traveling speed detection circuit (not shown) or a generated voltage detection circuit (not shown) is provided, and switches 17a, 17b, 2
1 and 25 may be configured with a relay circuit or the like.

In the operation, first, the so-called power running mode, which is the operation when running is driven by the rotation of the motor using the electric power of the storage battery 1 as the drive source, will be explained. In this case, the switch 21 is first switched to the switching terminal 21b side, and the switch 25 is switched to the switching terminal 25b side. Then, a current is applied to the gate of the transistor 26, making it conductive. Accordingly, the field winding 24 has a switch 21→shunt resistor 2.
A field current flows in the direction 3→field winding 24→switch 25→transistor 26. By this,
The motor is allowed to rotate.

Next, an accelerator pedal (not shown) is depressed, and the main switch 2 is closed accordingly. A pulse-like control signal having a duty ratio corresponding to the amount of depression of the accelerator pedal is applied to the base of the transistor 6. As a result, the transistor 6 is turned on and off, and the current flowing through the armature 4a is controlled intermittently. Here, if the amount of depression of the accelerator pedal is increased, the positive pulse period in one cycle of the control signal applied to the base of the transistor 6 becomes longer. Therefore, the amount of current flowing through the armature 4a increases overall, and the rotational speed of the motor increases. Conversely, when the amount of depression of the accelerator pedal decreases, the positive pulse period in one cycle of the control signal applied to the base of the transistor 6 becomes shorter, and the amount of current flowing through the armature 4a decreases overall. . Accordingly, the rotation speed of the motor decreases. In this way, the traveling speed is controlled.

Next, the operation when charging the storage battery 1 using a stationary charging device will be described. in this case,
Transistor 26 is rendered non-conductive and field current is cut off. Further, the transistor 6 is rendered non-conductive. And switches 17a and 17
b is opened. Next, an AC power source of a stationary charging device (not shown) is connected to the terminals 16a and 16b. As a result, the primary winding 5 of the transformer 5
Since alternating current flows through b, the secondary winding 5 of the transformer 5
An alternating current voltage is induced at a. This induced voltage is rectified by rectifying diodes 8 to 11 and applied to the storage battery 1. As a result, the storage battery 1 is charged.

More specifically, when the voltage induced in the reactor winding 5a, which is the secondary winding, has the polarity shown, the charging current is as follows: reactor winding 5a → armature 4a → shunt resistor 3 → diode 8 → fuse 7 → storage battery 1 → the negative side of the storage battery 1 → the fuse 12 → the diode 10 → the reactor winding 5a. When the voltage induced in the reactor winding 5a is opposite to the illustrated polarity, the charging current is as follows: reactor winding 5a → diode 11 → fuse 7 → positive side of storage battery 1 → negative side of storage battery 1 → fuse 12 → diode 9 It flows through the path of → shunt resistor 3 → armature 4a → reactor 5a.

Next, the operation in a so-called regeneration mode, which is a mode in which the storage battery 1 is charged while the vehicle is coasting with the accelerator open, will be described. The mode of the charging operation during coasting is switched between high-speed running and low-speed running. This is because, as mentioned above, when driving at high speeds, the voltage generated by the motor is high, so the storage battery 1 can be charged directly, but when driving at low speeds, the voltage generated by the motor is low, so the voltage is boosted by the transformer 5 and then the storage battery 1 is charged. Because it has to be.

First, the charging operation during high-speed driving will be explained. In this case, the switch 21 is connected to the switching terminal 21.
is switched to the b side, and the switch 25 is connected to the switching terminal 25.
Switched to side b. Therefore, the field winding 24
The field current flows in the same direction as during normal power running. Also, switches 17a and 17b remain open. Further, no control signal is applied to the base of the transistor 6, and the transistor 6 is turned off.
In this condition, when the motor rotates, armature 4
A generated voltage is induced in a with the polarity shown. Therefore, the charging current of the storage battery 1 is as follows: armature 4a → shunt resistor 3 → diode 8 → fuse 7 → positive side of battery 1 → negative side of battery 1 → fuse 12 → diode 10 → reactor winding 5a → armature 4a flows along the route of

Next, a charging operation when the traveling speed decreases below a predetermined speed and the generated voltage of the motor becomes below the battery voltage of the storage battery 1 will be described. in this case,
Switches 17a and 17b are closed. Further, the switch 21 is switched to the switching terminal 21c side, and the switch 25 is switched to the switching terminal 25c side. Therefore, the direction of the current flowing through the field winding 24 is reversed. Therefore, the polarity of the generated voltage generated in the armature 4a is opposite to the illustrated polarity. Further, a control signal is applied to the base of the transistor 6 in response to the vehicle speed decreasing below a predetermined speed or the voltage generated by the armature 4a decreasing below a predetermined voltage. At this time, the main switch 2 is open because the accelerator is not depressed. Therefore, from the storage battery 1 to the armature 4a
No current flows through. Instead, armature 4a→
Reactor winding 5a → transistor 6 → fuse 12 → diode 9 → shunt resistor 3 → armature 4
A current closed loop is formed along the path a. and,
The transistor 6 controls on and off the current flowing in the current closed loop. By this, 1 of transformer 5
An alternating current voltage is induced in the next winding 5b. If the number of turns of the primary winding 5b is greater than the number of turns of the reactor winding 5a, the AC voltage induced in the primary winding 5b will be boosted by the turn ratio. 1
When the alternating current voltage induced in the secondary winding 5b has the polarity shown, that is, when the transistor 6 turns on, the charging current changes from the primary winding 5b to the switch 17a to the diode 18 to the induction coil 20 to the fuse 7 to the storage battery 1. Positive side → negative side of storage battery 1 → switch 17b
→Flows through the path of the primary winding 5b. transistor 6
If it turns off, the armature 4a → reactor winding 5a will be turned off due to self-induction of the reactor winding 5a, etc.
A charging current flows through the path of → diode 11 → fuse 7 → storage battery 1 → fuse 12 → diode 9 → shunt resistor 3 and armature 4a.

As mentioned above, in the embodiment shown in FIG. 1, even if the running speed of the vehicle decreases and the generated voltage of the motor becomes lower than the storage battery 1, the generated voltage is boosted by the charging transformer 5 and then rectified to restore the storage battery 1. This allows charging even when driving at low speeds, which was previously impossible.

FIG. 2 is a circuit diagram showing another embodiment of this invention. In the configuration, the positive side of the storage battery 31 includes a fuse 32, a main switch 33, and a shunt resistor 3.
4 and the armature 35 to the reactor RE. This reactor RE has a center tap type, and has a first winding W21 at one end from the center tap and a second winding W22 at the other end from the center tap. The armature 35 is connected to the center tap of the reactor RE. The other end of the winding W21 is connected to the negative side of the storage battery 31 via a transistor 36. Further, the other end side of the winding W22 is connected to the storage battery 31 via the transistor 37.
connected to the negative side of A pulse-like control signal as shown in FIG. 3 is applied to the base of the transistor 36 and the base of the transistor 37 to control the current flowing through the armature 35 intermittently. That is, a storage battery 31, a fuse 32, a main switch 33,
shunt resistance 34, armature 35, reactor RE,
Transistor 36 and transistor 37 constitute an armature current control circuit. Five rectifying diodes 38 to 42 are connected in connection with this armature current control circuit. The diode 38 has its anode connected to the negative side of the storage battery 31, and its cathode connected to the connection point between the main switch 33 and the shunt resistor 34. The diode 39 has its anode connected to one end of the winding W21, and its cathode connected to the connection point between the fuse 32 and the main switch 33. The diode 40 has its anode connected to one end of the winding W22, and its cathode connected to the connection point between the fuse 32 and the main switch 33. The diode 41 has its anode connected to the negative side of the storage battery 31, and its cathode connected to the center tap of the reactor winding RE.
The diode 42 has its anode connected to the connection point between the main switch 33 and the shunt resistor 34,
Its cathode is connected to the connection point between the main switch 33 and the shunt resistor 32.

Similar to the circuit of FIG. 1, the reactor winding RE is used as the secondary winding of the charging transformer 50. Terminals 51a and 51b are connected to both ends of the primary winding W1 of the transformer 50, respectively. An AC power source is connected to these terminals 51a and 51b when charging is performed using a stationary charging device (not shown). Further, both ends of the secondary winding W1 are connected to the input end of a full-wave rectifier bridge 53 via switches 52a and 52b, respectively. The + side output terminal of this full wave rectifier bridge 53 is connected to the fuse 32.
It is connected to the positive side of the storage battery 31 via. Also,
The negative output terminal of the full-wave rectifier bridge 53 is connected to the storage battery 31
connected to the negative side of

On the other hand, field winding 54 cooperates with armature 35 to constitute motor M, and switches 55 and 56 are connected to both ends thereof, respectively. switch 55
is the common contact 55a connected to the input terminal 57a
and a switching terminal 5 connected to one end of the field winding 54.
5b, and a switching terminal 55c connected to the other end of the field winding 54. The switch 56 is an input terminal 57
A common contact 56a connected to b, and a field winding 54
It includes a switching terminal 56b connected to the other end, and a switching terminal 56c connected to one end of the field winding 54. These switches 55 and 56 are connected to the field winding 5
4 is used to reverse the direction of the current flowing through the circuit. Field voltages are applied to the input terminals 57a and 57b with the polarities shown.

FIG. 3 is a waveform diagram of control signals applied to the bases of transistors 36 and 37 shown in FIG. 2. The operation of another embodiment of this invention will be described below with reference to FIGS. 2 and 3.

First, the travel control operation during power running will be explained. In this case, switches 52a and 52
b is opened. Further, the switch 55 is switched to the switching terminal 55b side, and the switch 56 is switched to the switching terminal 56b side. switch 55 and 5
6, a field current flows through the field winding 54 in the direction of input terminal 57a→switch 55→field winding 54→switch 56→input terminal 57b. On the other hand, when an accelerator pedal (not shown) is depressed, the main switch 33 is closed. and,
Control signals as shown in FIG. 3 are applied to the bases of transistors 36 and 37, respectively. This control signal causes transistors 36 and 37 to
is alternately turned on and off to control the armature current intermittently. In this way, in the circuit of FIG. 2, the armature current is controlled intermittently using the two transistors 36 and 37, so the transistor 3
The average current flowing through each of 6 and 37 is the first
It can be reduced to one-half compared to the circuit shown in the figure. Therefore, since each transistor generates less heat, there are advantages that the transistor can be made smaller and cheaper. As is well known, the lower the current capacity of a transistor, the cheaper it is, but as the current capacity increases, it becomes synergistically more expensive. Therefore, as in this example, transistors with small current capacity are connected in parallel. In this case, the cost is extremely low compared to the case where one transistor with a large current capacity is used. Also, transistors 36 and 3
7 are made alternately conductive, windings W21 and W22
Because current flows alternately between the reactor winding
The heat capacity of RE can be reduced.

Next, the operation of charging using a stationary charging device (not shown) will be described. In this case, no field voltage is applied to the input terminals 57a and 57b, and no field current flows through the field winding 54. Further, switches 52a and 52b are opened, and AC power is connected to terminals 51a and 51b.
Furthermore, transistors 36 and 37 are turned off. Now, suppose that current is flowing from the input terminal 51a to the input terminal 51b via the primary winding W1 due to the AC power supply connected to the input terminals 51a and 51b. In this case, the winding of the reactor winding RE Charging is performed based on the secondary voltage induced in W21. That is, in this case, the charging current flows along the path of winding W21→diode 39→fuse 32→storage battery 31→diode 41→winding W21. On the contrary, when current flows from the input terminal 51b to the secondary winding 51a via the secondary winding W1, charging is performed based on the voltage induced in the winding W22. That is, in this case, the charging current is as follows: winding W22 → diode 40 → fuse 32 →
It flows along the path of storage battery 31 → diode 41 → winding W22.

Next, a charging operation during coasting will be described. Similar to the circuit shown in FIG. 1, the mode of charging during coasting is switched between high speed and low speed travel.

First, the charging operation during high-speed driving will be explained. In this case, the switch 55 is connected to the switching terminal 55.
The switch 56 is switched to the switching terminal 56.
Switched to side b. Also, switches 52a and 52b are opened. In this state, a generated voltage of the illustrated polarity is generated in the armature 35. Therefore, a charging current flows through the path of armature 35 → shunt resistor 34 → diode 42 → fuse 32 → storage battery 31 → diode 41 → armature 35. As a result, the storage battery 31 is charged.

Next, when the traveling speed falls below a predetermined speed and the generated voltage of the motor M falls below the battery voltage of the storage battery 31, the switches 52a and 52b are closed.
The switch 55 is switched to the switching terminal 55c side,
The switch 56 is switched to the switching terminal 56c side. By switching switches 55 and 56,
The direction of the current flowing through the field winding 54 is reversed, and the polarity of the generated voltage generated in the armature 35 becomes opposite to the illustrated polarity. At this time, a control signal as shown in FIG. 3 is applied to the bases of the transistors 36 and 37 to turn them on and off. Therefore,
While the transistor 36 is on, the armature 3
A current flows through the path of 5→winding W21→transistor 36→diode 38→shunt resistor 34→armature 35. Also, when the transistor 37 is on, the armature 35 → winding W22 → transistor 37 → diode 38 → shunt resistor 34 →
Current flows through the armature 35 path. in this way,
Current flows intermittently through the windings W21 and W22. Therefore, a boosted voltage is induced in the primary winding W1. This voltage is rectified by a full-wave rectifier circuit 53 and applied to the storage battery 31. As a result, the storage battery 31 is charged.

As described above, according to this invention, when charging a storage battery while driving, the voltage generated by the DC motor is boosted using a conventional charging transformer to charge the storage battery. Charging can be performed even when driving at low speeds, where charging would otherwise not be possible. Therefore, charging efficiency is dramatically improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of this invention. FIG. 2 is a circuit diagram showing another embodiment of this invention. FIG. 3 shows the transistor 36 shown in FIG.
and 37 are waveform diagrams of control signals given to each base. In the figure, 1 and 31 are storage batteries, 4a and 35 are armatures, 24 and 54 are field windings,
6, 36 and 37 are transistors for armature current intermittent control; 5 and 50 are charging transformers;
21, 25, 55 and 56 indicate switches for reversing the field current.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An armature current control circuit formed by connecting in series a storage battery, an armature of a running DC motor, a reactor, and a chopper control circuit for controlling the power supplied to the armature intermittently. and further includes a charging transformer that uses the reactor as a secondary winding and has a primary winding magnetically coupled to the secondary winding, and when charging, an alternating current is applied to the primary winding of the charging transformer. In a control device for an electric vehicle that connects a power source and thereby rectifies the voltage induced in the secondary winding and applies it to the storage battery to charge the storage battery, the electric vehicle is connected to the storage battery and the armature is is,
Accelerator interlocking switch means that is closed only when the accelerator of the electric vehicle is depressed, at least a first diode connected in parallel to the accelerator interlocking switch means, and a second diode connected in parallel to the chopper control circuit. a first regeneration means for charging the storage battery with a voltage corresponding to a back electromotive voltage of the armature; and at least means for reversing the polarity of the field current of the DC motor; means for rectifying a voltage induced in the primary winding by intermittent control of a current based on a back electromotive voltage of the voltage with the chopper circuit, and supplying the rectified voltage to the storage battery, the secondary winding and the primary winding A control device for an electric vehicle, comprising second regeneration means for charging the storage battery with a voltage boosted according to a turns ratio with respect to a wire. (2) The polarity reversing means includes means for detecting the rotation speed of the DC motor and reversing the polarity of the field current when the rotation speed is below a predetermined rotation speed. Electric vehicle control device. (3) The polarity reversing means includes means for detecting a back electromotive voltage of the armature and reversing the polarity of the field current when the voltage is below a predetermined voltage, as set forth in claim 1 of the utility model registration claim. Electric vehicle control device. (4) The control device for an electric vehicle according to claim 1, wherein the polarity reversing means includes means for reversing the polarity of the field current in response to a manual operation.