JPH0221201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an electric vehicle, and more particularly to an improvement in a control device that controls the running state of an electric vehicle by continuously controlling DC power using a chopper and supplying the DC power to a DC motor.

Conventionally, as a device for controlling the running speed of an electric vehicle, a device is known that uses a chopper using a large-capacity transistor or SCR to intermittently control the power supplied to a DC motor. This control device connects the armature, reactor, and chopper of a DC motor (hereinafter referred to as motor) in series to the storage battery.
The electric power supplied to the motor is controlled by intermittently turning the chopper on and off.

By the way, since electric vehicles use electric power stored in storage batteries as their driving source, there is a limit to the distance that they can travel on one charge. For this reason, conventional electric vehicles had to charge their storage batteries every time they traveled a certain distance. Therefore, users of electric vehicles have been required to have a charging device. Such charging devices are extremely large in size and expensive, which has hindered the spread of electric vehicles.

Therefore, the applicant of the present application previously proposed in Japanese Patent Laid-Open No. 54-90708 a speed control circuit for an electric vehicle that also has a charging function. According to the invention proposed earlier, a transformer and a transistor including an armature and a secondary winding including a center tap are connected in series to a storage battery, the secondary winding is used as a reactor, and the primary winding of the transformer is connected in series with a storage battery. When alternating current is supplied to the secondary winding, the alternating current induced in the secondary winding is rectified and supplied to the storage battery. However, since the previously proposed invention uses the secondary winding of a center-tapped transformer as a reactor, it has the problem that the transformer becomes large and heavy, making it extremely expensive. Furthermore, the previously proposed invention rectifies the alternating current induced in the secondary winding of the center-tapped transformer, and therefore has the problem of poor efficiency.

Therefore, an object of the present invention is to make a transformer in which the secondary winding also serves as a reactor smaller and lighter, and to be manufactured at a lower cost, and which also has driving control functions for electric vehicles, charging functions for storage batteries, and regeneration of generated power. An object of the present invention is to provide a control device for an electric vehicle that has three functions.

To summarize, this invention uses a transformer whose secondary winding is used as a reactor as an ordinary transformer (i.e., not a transformer with a center tap), and full-wave rectifies the alternating current induced in the transformer's secondary winding. A full-wave rectifier circuit is provided to feed the storage battery.
The full-wave rectifier circuit includes at least four rectifying elements. Furthermore, a fifth rectifying element is inserted between the armature and the reactor, and its anode is connected to the armature side and its cathode is connected to the reactor side, and a series circuit of the fifth rectifying element, the reactor, and the chopper. , and is inserted between the armature and the negative electrode of the storage battery, with its anode connected to the negative electrode side of the storage battery and its cathode connected to the armature side.
A connection point between the fifth rectifying element and the reactor supplies the current output from the positive electrode of the storage battery to one end of the armature in the power running mode, and supplies the regenerative current output from one end of the armature in the regeneration mode to the fifth rectifying element and the reactor. Switch means are provided for being switched to supply the same.

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

FIG. 1 is a circuit diagram of a control device for an electric vehicle according to an embodiment of the present invention. In the configuration, storage battery 1
1 is connected to an armature current control circuit formed by connecting in series the main switch 12, an armature 14a included in the motor 14, a reactor 152, a shunt resistor 13, and a large capacity transistor 16a, which is an example of a chopper. Note that a fuse 17 may be inserted in the armature current control circuit as necessary. The reactor 152 also serves as the secondary winding of the transformer 15. The transformer 15 has a primary winding 151 magnetically coupled to a reactor or a secondary winding 152.
including. A full-wave rectifier circuit 18 is provided in association with the reactor 152 and the storage battery 11.

The full-wave rectifier circuit 18 includes diodes 181 to 184, which are examples of four rectifier elements. diode 18
1 is connected in parallel to the main switch 12. The diode 182 connects the shunt resistor 13 and the collector of the transistor 16a, and the storage battery 11.
connected between the positive electrode and the positive electrode of the diode 183
has its anode connected to the negative electrode of storage battery 11 via fuse 17', and its cathode connected to the anode of diode 182. Diode 184 has its anode connected to the anode of diode 183 and its cathode connected to diode 1.
81 anode. That is, the full-wave rectifier circuit 18 is configured as a bridge rectifier circuit consisting of diodes 181 to 184, and its input side is connected to both ends of the series circuit of the armature 14a and the reactor 152, and its output side is connected to both ends of the storage battery 11. ing. Here, the diode 181
supplies a generated current, that is, a regenerative current, to the storage battery 11 when the motor 14 is operated as a generator, and also supplies an alternating current induced in the reactor 152 when an alternating current power source is connected to the primary winding 151 of the transformer 15. It has two functions: rectifying the current and supplying it to the storage battery 11 as a charging current. In other words, diode 181 is connected to a current path through which both the opening current and the charging current flow. diode 18
2 is inserted in the current path through which both the charging current and the freewheeling current flow.

Preferably, the diode 183 uses a thyristor as an example of a rectifying element with a control electrode in order to control the charging current.

A surge voltage absorption circuit 19 is connected between the cathode of the diode 182 and the negative electrode of the storage battery 11. The surge voltage absorption circuit 19 includes a coil 191
and a capacitor 192 in series. Note that, if necessary, the freewheel current bus circuit 21 may be connected between the cathode of the diode 182 and the anode of the diode 181. Freewheel current bus circuit 21 includes a switch 211 and a diode 212 connected in series.

Furthermore, the main switch 12 and the armature 14
A field current control circuit is connected between the connection point a and the negative electrode of the storage battery 11. The field current control circuit includes a resistor 22, a shunt resistor 23, a field winding 14f of the motor 14, and a transistor 16f connected in series, and the resistor 22, shunt resistor 23, and field coil 1.
A freewheeling diode 241 is connected in parallel to the 4f series circuit, and a transistor 16f is connected in parallel.
A diode 242 is connected in parallel to the diodes 242.

FIG. 2 is a block diagram of a circuit for controlling the operation of the control circuit of FIG. In the figure, the shunt resistor 13 is connected to an armature current detection circuit 131.
It also works as a charging current detection circuit 132. The outputs of armature current detection circuit 131 and charging current detection circuit 132 are provided to control signal generation circuit 27. The control signal generation circuit 27 is further supplied with the outputs of the storage battery voltage detection circuit 25 and the accelerator operation state detection circuit 26 .

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to FIGS. 1 and 2.

First, the operation when driving an electric vehicle,
A so-called car driving mode is established. In this case, the main switch 12 is closed. and,
An accelerator (not shown) is depressed. depending on,
The accelerator operation state detection circuit 26 provides a control signal generation circuit 27 with a signal proportional to the accelerator operation state. The control signal generation circuit 27 derives an armature current (or voltage) control signal c1 and applies it to the base of the transistor 16a based on the operating state of the accelerator, and also derives a field current control signal c2 and applies it to the base of the transistor 16f. give to The armature current control signal c1 is a signal in which the negative pulse period is longer than the positive pulse period when the accelerator is depressed lightly, and the negative pulse period is shorter than the positive pulse period when the accelerator is deeply depressed. It becomes a signal. On the other hand, field current control signal c2
is a signal in which the positive pulse period is longer than the negative pulse period when the accelerator is depressed lightly,
The opposite is true when the accelerator is depressed deeply. In this manner, when the pulsed armature current control signal c2 is applied, the transistor 16a performs an on-off operation to control the armature current intermittently. When the transistor 16a is switched from the on state to the off state, the magnetic energy stored in the reactor 152 causes a free wheel to flow into the closed loop of the diode 182 - main switch 12 - shunt resistor 13 - armature 14a - reactor 152 - shunt resistor 13. Ring current flows. Further, the surge voltage generated when the transistor 16a is in the off state is absorbed by the surge voltage absorption circuit 19. In this way, transistors 16a and 16f
By repeating the on-off operation, the traveling speed of the electric vehicle is controlled.

Next, a description will be given of the operation when the motor 14 is used as a generator to regenerate generated power during downhill or coasting travel, that is, the regenerative travel mode. In this case, the main switch 12 is opened in succession to the accelerator pedal, for example. Then, the control signal generation circuit 27 stops deriving the armature current control signal c1 (that is, sets the signal c1 to low level), and controls the field current based on the outputs of the charging current detection circuit 132 and the storage battery voltage detection circuit 25. A signal c2 is applied to the transistor 16f. At this time, the field current is being supplied to the field coil 14f, so the motor 14 works as a generator. The generated output of the motor 14 is transmitted from the armature 14a to the storage battery 1 through the diode 181, fuse 17, storage battery 11, fuse 17', diode 183, and shunt resistor 13.
It is regenerated to 1.

Next, the operation when charging the storage battery 11 with an external AC power source using the transformer 15 will be described.
In this case, main switch 12 is opened and signals c1 and c2 are not derived, so transistors 16a and 16f remain off. An alternating current power source (AC) is connected to the primary winding 151 of the transformer 15. When the power supply voltage has the illustrated polarity, the voltage induced in the reactor 152 causes a secondary current to flow through the armature 14a - diode 181 - fuse 17 - storage battery 11 - fuse 17' - diode 183 - shunt resistor 13 - reactor 152. flow, storage battery 1
Charge 1. On the other hand, when the power supply voltage has a polarity opposite to that shown in the figure, the voltage induced in the reactor 152 causes the current to flow between the shunt resistor 13 and the diode 18.
2-Fuse 17-Storage battery 11-Fuse 17'
It flows through - diode 184 - armature 14 a - reactor 152 and charges storage battery 11 . In this manner, the aforementioned operation is repeated for each half cycle of the AC power supply to charge the storage battery 11.

Note that if a thyristor is used in the position of the diode 183, it is possible to control the charging current. That is, the control signal generation circuit 27 operates based on the current flowing through the shunt resistor 13, in other words, the charging current detected by the charging current detection circuit 132 and the storage battery voltage detected by the storage battery voltage detection circuit 25. A gate signal g is generated and applied to the gate of thyristor 183'. This gate signal g is selected to have a phase such that the conduction angle of the thyristor 183' becomes small in order to limit the rush current at the start of charging. After a certain period of time has elapsed from the start of charging, the gate signal g is generated with a phase suitable for flowing a normal charging current. This state continues for a relatively long time. When the storage battery voltage detection circuit 25 detects a voltage close to full charge, the charging current is limited because the battery is in the final stage of charging.

As described above, according to the embodiment shown in FIG. 1, the transformer whose secondary winding also serves as a reactor can be constructed without a center tap, so there is an advantage that the transformer can be made smaller and lighter. Also,
At least one diode included in the full-wave rectifier circuit 18 is also used as part of the regenerative current path, and at least one other diode is also used as part of the path through which the freewheeling current flows. It also has the advantage of being simple and inexpensive to manufacture. Furthermore, according to this embodiment, three functions such as controlling the running speed of the electric vehicle, regenerating the generated power, and charging the storage battery with externally supplied AC power are reliably performed using a common circuit. There is also the advantage of being able to

Note that in this embodiment, the diodes 241, 2
42 is inserted, the diode 184
Since the function of 184 can be substituted completely equivalently by these two diodes, it is possible to omit the diode 184.

FIG. 3 is a circuit diagram of a control device for an electric vehicle according to another embodiment of the present invention. In the configuration, the storage battery 11 includes a main switch 31, an armature 14a,
An armature current control circuit consisting of a series circuit of diode 321, shunt resistor 13a, reactor 152, and transistor 16a is connected. The reactor 152 is connected to the transformer 15 in the same way as in FIG.
The next winding is utilized. A full-wave rectifier circuit 18a is connected to both ends of the reactor 152. The full-wave rectifier circuit 18a is constructed by bridge-connecting four diodes 181 to 184. That is, a connection point between the anode of the diode 181 and the cathode of the diode 184 is connected to one end of the reactor 152. The connection point between the anode of the diode 182 and the cathode of the diode 183 is the reactor 152.
connected to the other end of the A connection point between the anodes of diodes 183 and 184 is connected to the negative electrode of storage battery 11 . A connection point between the cathodes of diodes 181 and 182 is connected to the positive electrode of storage battery 11 via shunt resistor 13b.

The main switch 31 is a changeover switch capable of switching the movable contact 311 between an a contact and a b contact. The b contact of the main switch 31 is connected to the cathode of the diode 321 via a diode 322. Diode 321, shunt resistor 13
a, reactor 152 and transistor 16a
A diode 323 is connected in antiparallel to the series circuit of . Diodes 322 and 323 are used to cause regenerative current to flow in a fixed direction.

Furthermore, a field current control circuit is connected between the positive and negative electrodes of the storage battery 11. The field current control circuit is constructed by connecting the field current switching switch 33, the field winding 14f of the motor 14, and the transistor 16b in series, and by connecting the freewheel diode 241 in parallel to the field coil 14f. .

Next, the operation shown in FIG. 3 will be explained. In the case of traveling mode, the movable contact 31 of the main switch 31
1 is connected to the a contact, and the switch 33 is closed. Similarly to the embodiment of FIG. 1, armature current control signal c1 is applied to the base of transistor 16a, and field current control signal c2 is applied to the base of transistor 16f. This causes the motor 14 to rotate.

Note that when the transistor 16a is switched from the on state to the off state, an induced voltage is generated at both ends of the reactor 152 due to magnetic energy. A freewheeling current based on this voltage flows through a closed circuit of diode 182, shunt resistor 13b, main switch 31, armature 14a, diode 321, shunt resistor 13a, and reactor 152.

In regenerative driving mode, main switch 3
The first movable contact 311 is switched to the b contact, and the switch 33 is closed. In this case, the transistor 16a remains off, and the transistor 16f is turned on and off by the field current control signal c2. Therefore, the motor 14 functions as a DC generator and generates DC power. This power generation output is the main switch 31-diode 32
2-Shunt resistor 13a-Diode 181-Shunt resistor 13b-Storage battery 11-Diode 32
3 and charges the storage battery 11. When the speed of the motor 14 decreases and its generated voltage becomes lower than the voltage of the storage battery 11, the regenerative current in the loop will no longer flow. Accordingly, transistor 16
a is turned on, the power generation output of the motor 14 is
4a to main switch 31-diode 322
It flows through the closed circuit of - shunt resistor 13a - reactor 152 - transistor 16a - diode 323. At this time, magnetic energy is accumulated in the reactor 152, and a high voltage is generated across the reactor 152 when the transistor 16a is turned off. This voltage and the voltage generated by the armature 14a cause the armature 14a - main switch 31 - diode 322 - shunt resistor 13a - reactor 1
52-Diode 182-Shunt resistor 13b-
A regenerative current flows in the storage battery 11-diode 323 loop. After that, the transistor 16a is turned on.
By repeating turning off, there is an advantage that the generated power can be efficiently regenerated to the storage battery 11 even when the electric vehicle is traveling at a relatively slow speed and the generated voltage is low.

In the charging mode using an external power source, the movable contact 311 of the main switch 32 is connected to the b contact, and the switch 33 is opened. The primary winding 151 of the transformer 15 is then connected to an AC power source. During the illustrated half-cycle period when the voltage polarity of the AC power source is the illustrated half-cycle period, the secondary voltage induced in the reactor 152 causes the diode 181 - shunt resistor 13b - storage battery 11 - diode 183 -
A charging current flows through the reactor 152 path. During a half cycle in which the power supply voltage of the AC power supply has a polarity opposite to that shown in the figure, the secondary voltage induced in the reactor 152 causes the diode 182 - shunt resistor 1 to
A charging current flows through the closed circuit of 3b-storage battery 11-diode 184-reactor 152.

This embodiment has the same advantages as FIG.
Even when the voltage generated by the motor 14 is lower than the voltage of the storage battery 11, there is an advantage that the storage battery can be efficiently charged.

Note that also in this embodiment, the diode 32
1 and 323 can be substituted for the action of diode 184. In that case, when charging externally, diodes 181 to 183 and diode 3
21 and 323 constitute a bridge circuit.

As described above, according to the present invention, since there is no need to use a transformer with a center tap, the transformer can be made lighter and smaller, and can be manufactured at a lower cost. Further, according to the present invention, a common circuit is used to perform control that combines three functions: driving control of an electric vehicle, regeneration control that charges the storage battery with generated power, and charging control that charges the storage battery with an external AC power source. There are also benefits to the device. Furthermore, according to the present invention, even if the generated voltage of the armature is lower than the output voltage of the storage battery when the electric vehicle is running at low speed, the storage battery can be charged and regenerative braking can be performed, and the kinetic energy of the electric vehicle can be effectively utilized. can do. Furthermore, the full-wave rectifier circuit that rectifies the voltage across the reactor is also used for the current path in regenerative braking, so it is possible to control the running of an electric vehicle, regenerative control, and charging control using an external AC power source with an extremely simple circuit configuration. be able to.

It goes without saying that the present invention can also be applied to hybrid vehicles equipped with both an engine and a motor as drive sources.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a control device for an electric vehicle according to an embodiment of the present invention. FIG. 2 is a block diagram of a control signal generation circuit for controlling the operation of FIG. 1. FIG. 3 is a circuit diagram of a control device for an electric vehicle according to another embodiment of the present invention. In the figure, 11 is a storage battery, 12 and 31 are main switches, 13, 13a, 13b are shunt resistors, 14 is a motor, 14a is an armature, 14f
is a field coil, 15 is a transformer, 151 is a primary winding, 152 is a reactor (secondary winding), 16a,
16f is a transistor (chiyotsupa), 18, 18
a is a full-wave rectifier circuit, 181-184, 321-3
23 is a diode, and 19 is a surge voltage absorption circuit.

Claims (1)

[Scope of Claims] 1. An armature current control circuit including at least a storage battery, an armature of a DC motor, a reactor, and a chopper for controlling the supply of power to the armature in series, An electric vehicle having a power running mode in which running is driven by an off operation, a regeneration mode in which the storage battery is charged by the voltage generated by the armature, and an external charging mode in which the storage battery is charged by an external AC power source. , the reactor is used as a secondary winding, and the reactor is used as a secondary winding.
A transformer including a primary winding magnetically coupled to a secondary winding, and full-wave rectification of the alternating current induced in the reactor when the external AC power source is connected to the primary winding in the off state of the chopper. and a full-wave rectifier circuit that supplies charging current to the storage battery as a charging current, and the full-wave rectification circuit includes at least a first rectifier element and a second rectifier element connected in a bridge manner between both ends of the reactor and both poles of the storage battery. a rectifying element, a third rectifying element, and a fourth rectifying element, the first rectifying element being inserted between one end of the reactor and the positive electrode of the storage battery, and the second rectifying element is inserted between the other end of the reactor and the positive electrode of the storage battery, the third rectifying element is inserted between the other end of the reactor and the negative electrode of the storage battery, and the fourth a rectifying element is interposed between one end of the reactor and a negative electrode of the storage battery, and further interposed between the armature and the reactor,
a fifth rectifying element having its anode connected to the armature side and its cathode connected to the reactor side; connected in parallel to the series circuit of the fifth rectifying element, the reactor, and the chopper; a sixth rectifier element interposed between the armature and the negative electrode of the storage battery, the anode of which is connected to the negative electrode side of the storage battery and the cathode connected to the armature side, and the positive electrode of the storage battery in the power running mode; A current outputted from the armature is supplied to one end of the armature, and when in the regeneration mode, a regenerative current outputted from one end of the armature is supplied to a connection point between the fifth rectifying element and the reactor. The fifth rectifying element conducts during the power running mode to form a drive current path to the armature, and cooperates with the second rectifying element when the chopper is turned off. a free oiling current path is formed, and when the generated voltage of the armature is higher than the output voltage of the storage battery in the regeneration mode, the chopper is turned off and the first rectifying element and the sixth rectifying element are turned off. The rectifying element is conductive to form a regenerative current path based on the voltage generated by the armature, and when the voltage generated by the armature is lower than the output voltage of the storage battery in the regeneration mode, the chopper is turned on and off. At the same time, when the chopper is turned on, the sixth rectifying element becomes conductive, forming a closed circuit including the armature, the reactor, and the chopper, and electromagnetic energy is accumulated in the reactor. A control device for an electric vehicle, wherein the second rectifying element and the sixth rectifying element are electrically connected to form a regenerative current path based on the generated voltage of the armature and the residual voltage of the reactor. 2. A seventh rectifying element inserted between a connection point between the fifth rectifying element and the reactor and the switching means.
Claim 1 further comprising a rectifying element.
A control device for an electric vehicle as described in Section 1. 3 The fourth rectifying element is connected to the fifth and sixth rectifying elements.
The control device for an electric vehicle according to claim 1, which is also used as a rectifying element.