JPH10178705A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric vehicle with an engine being usable within the range suited for engine characteristics. SOLUTION: A generator 3 rotated and driven coupled by an engine 1 generates electric power, corresponding to a rotating speed based on the field control by field current. The power is stored in a capacitor 4. Then, the engine 1 is rotated and driver based on the optimum torque characteristic, and the required generated energy is calculated based on the running state from time to time. The target-rotating speed for controlling the generator 3 corresponding to the generated energy is calculated based on the generated energy and the optimum torque characteristic of the engine 1. Then, based on the target rotating speed, the generator 3 is field-controlled, and the generator 3 is rotated and driven at a rotating speed which balances the drive torque of the generator 3 relative to the generated torque by the rotation of the engine 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric vehicle,
Specifically, a traveling motor driven by a battery voltage,
The present invention relates to a control device that controls power generation for charging a power storage device by an engine of a hybrid electric vehicle including an engine for charging the power storage device such as a battery.

[0002]

2. Description of the Related Art In recent years, some electric automobiles are equipped with an engine and a generator for storing electric power in a battery for supplying electric power to the motor in addition to a traveling motor. As shown in FIG. 8, an engine 51 as an internal combustion engine provided in an electric vehicle is, for example, a gasoline engine, and a generator 52 is connected to the engine 51. The throttle opening of the engine 51 is controlled by the controller 53 according to the operating conditions such as the accelerator opening at that time, and the generator 52 is driven to rotate by the rotation speed and the torque according to the throttle opening.

[0003] As the generator 52, for example, a surface magnet type electric motor in which a permanent magnet is attached to an outer diameter surface of a rotor is used. The generator 52 is driven to rotate by the rotation of the engine 51, and the generated power is stored in the battery 54. The electric power stored in the battery 54 is supplied to a traveling motor (not shown), and the traveling motor is controlled to rotate in accordance with the accelerator opening to rotate driving wheels (not shown).
An electric car runs.

[0004]

FIG. 9 shows an engine 5
The rotation speed-torque characteristic of the generated torque with respect to one engine rotation speed is indicated by a solid line for each throttle opening. In FIG. 9, a dashed line indicates the relationship between the number of rotations of the generator 52 and the required number of rotations of the driving torque versus the driving torque.

In general, the driving torque of the generator 52 composed of a surface magnet type motor is proportional to the number of revolutions and is represented by a straight line having a constant slope shown by a broken line in FIG. And the generator 52
Generates electric power according to the driving torque. on the other hand,
The torque generated by the engine 51 generally has characteristics as shown in FIG. 9 for each throttle opening. Then, the generator 52 is driven by the torque generated by the engine 51. That is, the engine 51 is operated at a rotational speed at which the torque generated by the engine 51 and the driving torque of the generator 52 are balanced. Therefore, in order to rotate and drive the generator 52 according to the amount of power generation required at each time, the throttle of the engine 51 is controlled such that the generated torque matches the driving torque of the generator.

[0006] However, the rotation speed-drive torque characteristics of the generator 52 do not conform to the use range of the engine 51. For example, the fuel consumption rate of the engine 51 used on the driving torque line of the generator 52 may be deteriorated, or the driving noise may be increased.

An object of the present invention is to provide an electric vehicle in which an engine can be used within a range suitable for characteristics.

[0008]

According to a first aspect of the present invention, there is provided an internal combustion engine which is connected to the internal combustion engine, is driven to rotate by the internal combustion engine, and controls a field by a field current. A generator that generates electric power according to the number of revolutions driven based on the electric power, a power storage device that stores the electric power generated by the generator, and a traveling motor that is rotationally driven based on the electric power supplied from the power storage device And, while rotating the internal combustion engine based on the optimal torque characteristics, calculate the required power generation amount based on the running state at each time, based on the generated power amount and the optimal torque characteristics of the internal combustion engine Calculating the target rotation speed as a target for controlling the generator corresponding to the power generation amount, based on the target rotation speed, field-control the generator, and the torque generated by the rotation of the internal combustion engine and Driving torque of the generator is summarized as further comprising a power generation controller for rotating the electric generator at a rotational speed balanced against.

According to a second aspect of the present invention, in the electric vehicle according to the first aspect, the power generation control device drives the internal combustion engine to rotate based on an optimal torque characteristic and changes the running state at each time. A rotation speed calculating means for calculating a target rotation speed of the generator corresponding to a required power generation amount, a rotation speed detecting means for detecting a respective rotation speed of the generator, and a detected rotation speed of the generator. A comparison means for comparing the target rotation speed with the target rotation speed; a field current calculation means for calculating a field current based on the comparison result; and a control means for performing field control on the generator based on the field current. The point is that

[0010] The invention described in claim 3 is the invention according to claim 1 or 2.
In the electric vehicle described in the above, the field current calculating means decreases the number of revolutions of the generator by increasing the field current when the number of revolutions is larger than the target number of revolutions, the The gist is that the field current is reduced when the rotation speed is lower than the rotation speed.

[0011] The invention according to claim 4 is the invention according to claims 1 to 3.
In the electric vehicle described in the above, the gist is that the generator is an internal magnet type electric motor. According to a fifth aspect of the present invention, in the electric vehicle according to any one of the first to fourth aspects, the torque characteristic of the internal combustion engine is such that at least one of fuel efficiency, noise, and emission of the internal combustion engine is an optimal torque characteristic. The gist is that there is.

[0012] The invention according to claim 6 is the invention according to claims 1 to 5.
In the electric vehicle described in the above, the traveling condition is at least one of a vehicle speed signal detecting a rotation speed of a traveling motor, a voltage stored in the power storage device, an accelerator opening signal, and a brake operation position. The main point is that it is based on

Therefore, according to the first aspect of the present invention,
A generator connected to the internal combustion engine and driven to rotate generates electric power according to the number of revolutions based on field control by a field current. The electric power is stored in the power storage device. Then, the internal combustion engine is driven to rotate based on the optimum torque characteristics, and the required power generation amount is calculated based on the running state at each time, and based on the generated power amount and the optimum torque characteristics of the internal combustion engine, A target rotation speed as a target for controlling the generator corresponding to the power generation amount is calculated, and based on the target rotation speed,
The generator is field-controlled, and the generator is rotationally driven at a rotational speed at which the driving torque of the generator balances the torque generated by the rotation of the internal combustion engine.

According to the second aspect of the present invention, the power generation control device includes a rotation speed calculation unit, a rotation speed detection unit, a comparison unit, a field current calculation unit, and a control unit. According to the rotation speed calculating means, the internal combustion engine is driven to rotate based on the optimum torque characteristics, and the target rotation speed of the generator corresponding to the required power generation amount is calculated based on the running state at each time. . The rotational speed of the generator is detected by the rotational speed detecting means. The detected rotation speed and the target rotation speed are compared by the comparing means, and the field current is calculated by the field current calculating means based on the comparison result. According to the control means, the generator is field-controlled based on the field current.

According to the third aspect of the invention, the field current calculating means increases the field current when the rotation speed is higher than the target rotation speed, reduces the rotation speed of the generator, and If the number is less than the target speed, the field current is reduced and the speed of the generator is increased.

According to the fourth aspect of the present invention, the generator is an internal magnet type electric motor, and generates electric power corresponding to the magnetic flux of the field generated based on the field current. According to the fifth aspect of the present invention, the torque characteristic of the internal combustion engine is such that at least one of the fuel efficiency, noise, and emission of the internal combustion engine is the optimal torque characteristic, and the target rotation speed is calculated based on the torque characteristic. You.

According to the sixth aspect of the present invention, the traveling conditions include a vehicle speed signal that detects the rotation speed of the traveling motor, a voltage stored in the power storage device, an accelerator opening signal, a brake operation position, Based on at least one of the above, the driving torque is controlled by controlling the field current of the generator, and the rotation speed of the internal combustion engine directly connected to the generator is controlled.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the electric vehicle includes an engine 1 as an internal combustion engine and a traveling motor 2, and is configured as a so-called hybrid vehicle. The engine 1 is, for example, a gasoline engine, and a generator 3 is connected to an output shaft 1a.
The generator 3 uses an internal magnet type electric motor, which is an AC motor, as a generator. The generator 3 is driven to rotate by the engine 1 and generates AC power according to the rotational speed at each time.

The generator 3 is connected with a capacitor 4 as a power storage means. The power generated by the generator 3 is temporarily stored in the capacitor 4. The stored electric power is supplied to the traveling motor 2.

The traveling motor 2 is composed of, for example, an AC induction motor, and its output shaft 2a is provided with a differential gear 5
The drive wheel 6 is connected via the. The traveling motor 2 is
The rotation is driven based on the electric power supplied from the capacitor 4. The rotation of the traveling motor 2 is transmitted to the driving wheels 6 via the output shaft 2a and the differential gear 5, and the driving wheels 6 are rotationally driven based on the transmitted rotation, so that the electric vehicle travels.

Therefore, the engine 1 is used only for rotating the generator 3 to supply electric power to the traveling motor 2. That is, the electric vehicle of the present embodiment is configured as a so-called series-type hybrid vehicle.

A converter 7 is inserted and connected between the generator 3 and the capacitor 4. Converter 7 is used to store electric power generated by generator 3 including an AC motor in capacitor 4. The converter 7 is a forward conversion circuit for converting AC into DC, converts AC generated by the generator 3 into DC and outputs the DC to the capacitor 4, and the capacitor 4 temporarily stores the DC converted power. .

Between the capacitor 4 and the traveling motor 2,
An inverter 8 is inserted and connected. The inverter 8
The electric power stored in the capacitor 4 is used to drive the traveling motor 2 composed of an AC motor. The inverter 8 is an inverse conversion circuit that converts DC to AC, converts the power stored in the capacitor 4 from DC to AC, and supplies the power to the traveling motor 2. The traveling motor 2 is driven to rotate based on the supplied alternating current.

The inverter 8 is connected to the converter 7, converts the power supplied from the generator 3 via the converter 7 from DC to AC, and supplies it to the traveling motor 2. Therefore, the traveling motor 2 is rotationally driven by the electric power stored in the capacitor 4 or the electric power generated by the generator 3. With this configuration, when the power supplied to the traveling motor 2 is insufficient with the power stored in the capacitor 4 due to a traveling state such as acceleration, the insufficient power is supplemented by adding the power supplied directly from the generator 3. Thus, it becomes possible to rotate the traveling motor 2 according to the traveling state and travel.

A rotation sensor 9 is provided on the output shaft 1a where the engine 1 and the generator 3 are connected. The rotation sensor 9 detects the rotation speed N of the generator 3 at each time, and outputs the detected rotation speed N.

A vehicle speed sensor 10 is provided on the output shaft 2a of the traveling motor 2. The vehicle speed sensor 10 detects rotation of the traveling motor 2. The rotation of the traveling motor 2 corresponds to (for example, is proportional to) the traveling speed (vehicle speed) of the electric vehicle. Accordingly, the vehicle speed sensor 10 detects the vehicle speed by monitoring the rotation of the traveling motor 2, and outputs a vehicle speed signal corresponding to the detected vehicle speed. The vehicle speed signal is input to the system controller 11.

The rotation number N of the generator 3 detected by the rotation sensor 9 is input to the system controller 11. An accelerator sensor (not shown) provided on the accelerator pedal is connected to the system controller 11, and an accelerator opening signal corresponding to the operation amount of the accelerator pedal detected by the accelerator sensor is input. The system controller 11 also includes a brake sensor (not shown) provided on the brake pedal.
Are connected, and a brake operation position signal corresponding to the operation position of the brake pedal detected by the brake sensor is input.

Further, a capacitor 4 is connected to the system controller 11, and the capacitor 4 at each time is connected.
Is input as a capacitor voltage. The system controller 11 includes a microcomputer or the like and includes a ROM 11a as a storage unit. A running control program for controlling the running motor 2 to control the running control of the electric vehicle is stored in the ROM 11a in advance. The system controller 11 has a ROM 11a
And outputs a motor torque signal to the inverter 8 based on the accelerator opening signal and the brake operation position signal in accordance with the traveling control program stored in the inverter 8 in order to generate a torque required each time. Thereby, the inverter 8
Supplies AC power to the traveling motor 2 based on a motor torque signal, and the traveling motor 2 generates a required number of revolutions and driving force by the supplied power.

In the ROM 11a, a power generation control program for controlling the power generation amount of the generator 3 is set and stored in advance. The amount of power generated by the generator 3 corresponds to the rotation speed of the generator 3. The amount of power generated by the generator 3 changes based on the capacitor voltage at that time and the running state such as the accelerator opening and the brake operation amount. Therefore, the system controller 11 calculates the target number of revolutions of the generator 3 based on the capacitor voltage and the running state in order to control the power generation amount of the generator 3. For the calculation of the target rotation speed, a torque characteristic map of the engine 1 stored in the ROM 11a is used.

In the torque characteristic map, for example, the fuel efficiency of the engine 1 is an optimal torque characteristic, and is previously obtained as a characteristic connecting points having the highest fuel efficiency on the equal output curve of the engine 1 by experiments or the like. . And ROM
11a has the engine 1 based on the torque characteristic map.
, The generated torque, the throttle opening, and the like. FIG. 4 shows the torque characteristic map as the number of revolutions of the engine 1 and the engine generated torque with respect to the number of revolutions.

The system controller 11 calculates a target rotation speed N0 based on the torque characteristic map. Then, the system controller 11 instructs the calculated target rotation speed N0 to the generator controller 12 provided in the system controller 11.

Further, the system controller 11 reads out the throttle opening stored in correspondence with the target rotation speed N0 from the ROM 11a based on the torque characteristic map.
Then, the system controller 11 sets a throttle (not shown) for controlling the intake air amount for the engine 1 to the throttle opening. With this configuration,
The engine 1 is driven with optimal torque characteristics of the fuel efficiency. Further, the throttle of the engine 1 is set at the target rotational speed N0.
, The throttle opening is uniquely set and is not finely controlled.

The generator controller 12 comprises a microcomputer or the like, and is used to control the number of revolutions of the generator 3. The rotation sensor 9 is connected to the generator controller 12, and a rotation detection signal corresponding to the number of rotations of the generator 3 detected by the rotation sensor 9 is input.

The generator controller 12 compares the current rotational speed N of the generator 3 based on the rotation detection signal (hereinafter referred to as an execution rotational speed) with a target rotational speed N0 specified by the system controller 11. . Then, an excitation current Id is output to converter 7 based on the comparison result.

As shown in FIG.
A plurality of transistors T1 to T6 and a control unit 7a are provided, and a diode is connected to each of the transistors T1 to T6 in parallel. Transistor T1 and transistor T2 are connected in series, and both transistors T1, T2
A connection point between the two is connected to a U-phase terminal of the traveling motor 2. Further, a transistor T3 and a transistor T4 are connected in series, and a connection point between the two transistors T3 and T4 is connected to a V-phase terminal of the traveling motor 2. Further, a transistor T5 and a transistor T6 are connected in series, and a connection point between the two transistors T5 and T6 is connected to each transistor T5 connected to the W-phase terminal of the traveling motor 2.
The bases 1 to T6 are connected to the control unit 7a.

The controller 7a is connected to the generator controller 12 shown in FIG. 1, and receives the field current Id and the torque current Iq from the generator controller 12. The control unit 7a changes the timing at which on / off control of each of the transistors T1 to T6 is performed based on the input field current Id and torque current Iq. For example, the three-phase alternating currents Iu, I generated in the generator 3 according to the respective rotational speeds
The phase for turning on / off each of the transistors T1 to T6 is shifted with respect to v and Iw. Then, a magnetic flux is generated in the generator 3 in accordance with the three-phase AC currents Iu, Iv, Iw and the phases of the transistors T1 to T6 that are on / off controlled. That is, the converter 7 outputs the electric power to the generator 3 based on the field current Id.
Field control means for generating magnetic flux.

The internal magnet type electric motor (IPM motor) used for the generator 3 is provided with a permanent magnet inside a core provided on the surface of the rotor, and the core has a magnetic field generated by the permanent magnet and a magnetic field generated by the stator. Occurs. These magnetic fields act between the rotor and the stator, and changing the strength of the magnetic field changes the driving torque required to rotate the rotor. The magnetic field generated by the permanent magnet is constant, and the magnetic field generated by the stator changes according to the three-phase alternating current supplied to the motor, and the three-phase alternating current is changed by controlling the field current. Therefore, by increasing or decreasing the field current, the driving torque with respect to the rotation speed, that is, the driving torque characteristic with respect to the rotation speed, can be changed.

Therefore, by controlling the field current to control the strength of the magnetic field (magnetic flux of the field) generated in the core by the magnetic field generated on the stator side, the characteristics of the driving torque with respect to the rotation speed can be changed. Can be.

That is, the generator 3 generates a voltage corresponding to the generated magnetic flux. For example, assuming that the magnetic flux Φ generated in the generator 3 and the rotation speed N at that time, the voltage V generated in the generator 3 is expressed as V = K1 × Φ × N. The current I generated in the generator 3 is
Assuming that the equivalent resistance R of the capacitor 4 is I = V / R. Further, the driving torque T of the generator 3 is expressed as T = K2 × I. Here, K1 and K2 are constants.

Therefore, from the above equation, for the rotational speed N,
By changing the magnetic flux Φ generated in the generator 3, the driving torque T of the generator 3 and, consequently, the generated voltage V can be changed. As a result, the drive torque characteristic of the generator 3 can be set to an arbitrary drive torque T for a certain number of rotations by performing field control as shown in FIG. A broken line where the torque is constant with respect to the rotation speed shown in FIG. 3 indicates the maximum driving torque of the generator 3, and the maximum driving torque is set to be equal to or more than the generated torque of the engine 1.

Accordingly, by driving the engine 1 at the rotation speed N and controlling the field of the generator 3, the generator 3 is driven to rotate at the point where the driving torque of the generator 3 balances the engine generated torque. Is done. The balanced point is a point where the engine generated torque characteristic and the drive torque characteristic of the generator 3 intersect as shown in FIG. And
The engine generated torque characteristic is set to the optimal torque characteristic of the fuel efficiency described above.

That is, the engine 1 is driven with the optimal torque characteristic of the fuel efficiency, and the field of the generator 3 is controlled to match the characteristic. The electric power generated by the generator 3 that is driven to rotate at the target rotational speed N0 is converted into a direct current by the converter 7 and supplied to the traveling motor 2 via the capacitor 4 and the inverter 8 as necessary electric power at each time. Is done.

Next, the calculation of the field current Id by the generator controller 12 will be described with reference to the calculation flowchart shown in FIG. In this case, the engine 1 is the one shown in FIG.
, The field current Id output to the converter 7 at this time is defined as a current I1. A case will be described in which the system controller 11 instructs the rotation speed N3 as the target rotation speed N0.

The generator controller 12 calculates and outputs the field current Id in accordance with steps (hereinafter simply referred to as S) 1 to S5 of the calculation flowchart shown in FIG.
First, in S1, the generator controller 12 sets the target rotation speed N0 instructed by the system controller 11.
Then, the rotation speed N of the generator 3 at that time is read from the rotation sensor 9.

Next, S2 is a rotation speed comparison process (rotation speed comparison means), in which the generator controller 12
The target rotation speed N0 is compared with the current rotation speed N of the generator 3, and based on the comparison result, it is determined whether the current rotation speed N is higher or lower than the target rotation speed N0. Specifically, the generator controller 12 determines whether the rotation speed N is larger than the target rotation speed N0 in S2. As a result, when the rotation speed N is less than the target rotation speed,
The generator controller 12 moves from S2 to S3. on the other hand,
When the rotation speed N is equal to or higher than the target rotation speed, the generator controller 12 proceeds from S2 to S4.

As shown in FIG. 4, the target rotation speed N0 (= N3) of the generator 3 is larger than the rotation speed N1 at that time. Therefore, in S2, the generator controller 12 determines that the rotation speed N (= N1) at that time is smaller than the target rotation speed N0 (= N3), and shifts from S2 to S3.

S3 is a field current calculation process (field current calculation means). The generator controller 12 determines a new field current Id based on the difference between the target rotation speed N0 and the rotation speed N at that time. Is calculated. The calculation of the field current Id is shown in FIG.
Is calculated based on a current change amount map for the rotational speed difference between the target rotational speed N0 and the rotational speed N as shown in FIG.
2a is stored in advance. In this map, the right side of the origin O is the current change amount ΔI (> 0) when the rotation speed difference (= N−N0) is positive, that is, when the rotation speed N is larger than the target rotation speed N0. On the left side of O, the current change amount ΔI (<0) when the rotation speed difference (= N−N0) is negative, that is, when the rotation speed N is smaller than the target rotation speed N0.

Therefore, the generator controller 12 sets S3
In step (1), a negative current change amount-[Delta] I corresponding to the rotation speed difference between the target rotation speed N0 and the rotation speed N is determined. Then, the generator controller 12 adds the current change amount −ΔI to the field current Id (= I1), and calculates a new current I2 (= I1−ΔI) obtained by reducing the current I1 by ΔI. That is, S3 constitutes a field current reduction process (field current reduction means). After calculating the new current I2, the generator controller 12 proceeds from S3 to S5.

S5 is a field current instruction process (field current instruction means), and the generator controller 12 in FIG.
The field current Id (= I2) calculated in step 3 is instructed to the converter 7. The control unit 7a of the converter 7 shown in FIG. 2 changes the timing of turning on / off each of the transistors T1 to T6 based on the instructed field current I2, and changes the magnetic flux of the field generated in the generator 3. .
Then, the driving torque of the generator 3 changes from point A to point B in FIG.
To decrease. Then, since the generated torque of the engine 1 becomes larger than the driving torque of the generator 3, the generator 3 is accelerated by the rotation of the engine 1 and the rotation speed of the generator 3 increases.

Next, the number of revolutions N of the generator 3 is increased and FIG.
When the vehicle moves to the point C shown in FIG. 6, the rotation speed N read by the generator controller 12 in FIG. 1 at S1 shown in FIG. 6 becomes the rotation speed N2. This rotation speed N2 is the target rotation speed N (= N3). Therefore, the generator controller 12 determines that the rotation speed N (= N2) at that time is larger than the target rotation speed N0 in S2 shown in FIG. 6, and shifts from S2 to S4.

S4 is a field current calculation process (field current calculation means) similar to S3.
Calculates a new field current Id based on the difference between the target rotation speed N0 and the rotation speed N at that time. At this time, since the rotation speed N is larger than the target rotation speed N0, the generator controller 12 determines the difference between the target rotation speed N0 and the rotation speed N based on the rotation speed difference-current change amount map shown in FIG. A positive current change amount ΔI corresponding to the rotational speed difference is obtained. Then, the generator controller 12 adds the current change amount ΔI to the field current Id (= I2), and calculates a new current I3 (= I2 + ΔI) obtained by increasing the current I2 by ΔI. That is, S4 constitutes a field current increasing process (field current increasing means). After calculating the new current I3, the generator controller 12 proceeds from S4 to S5.

In S5, the generator controller 12 in FIG. 1 calculates the field current Id (= I
3) is instructed to the converter 7. Control unit 7a of converter 7 shown in FIG.
The timing at which each of the transistors T1 to T6 is controlled to be turned on and off is changed based on the above, and the magnetic flux of the field generated in the generator 3 is changed. Then, the driving torque of the generator 3 is as shown in FIG.
From point C to point D. Then, since the generated torque of the engine 1 becomes smaller than the driving torque of the generator 3,
The generator 3 is decelerated by the load of the engine 1 and the generator 3
Rotation speed decreases.

Then, the generator controller 12 instantaneously repeats the above-described loop from S1 to S5, instructs the converter 7 on the field current Id calculated each time, and the controller 7a of the converter 7 instructs. The magnetic flux of the generator 3 is changed based on the field current Id. As a result, the generator 3
Is a point E which finally balances the generated torque of the engine 1;
That is, the rotation is stabilized at the target rotation speed N3.

As described above, in this embodiment,
The following effects are obtained. (1) The generator 3, which is connected to the engine 1 and driven to rotate, generates electric power according to the number of revolutions based on field control by a field current. The electric power is stored in the capacitor 4. Then, the engine 1 is driven to rotate based on the optimal torque characteristics, and the required power generation amount is calculated based on the running state at each time, and based on the generated power amount and the optimal torque characteristics of the engine 1, Generator 3 corresponding to power generation
Is calculated as a target rotation speed for controlling the rotation speed. And
The generator 3 is field-controlled based on the target rotation speed, and the generator 3 is driven to rotate at a rotation speed at which the driving torque of the generator 3 balances the torque generated by the rotation of the engine 1.

As a result, the engine 1 is driven with the optimum torque characteristics of the fuel efficiency, so that the fuel efficiency can be improved. In addition, the present invention may be implemented as follows in addition to the above-described embodiment.

In the above embodiment, the internal magnet type motor is used as the generator 3 capable of controlling the field current. However, other motors or generators may be used as long as the field current can be controlled. As a device capable of controlling the field current, there are, for example, a rotating armature type synchronous motor, a DC generator, an induction motor and the like in addition to the internal magnet type motor. Since the rotating armature type synchronous motor and the DC generator require a brush, maintenance is required as compared with the above embodiment. Further, since the induction motor is made only by the current, the efficiency may be lower than that of the above embodiment.

In the above embodiment, a gasoline engine is used as the engine 1 as the internal combustion engine. However, a gas engine, a diesel engine, a gas turbine, or the like may be used instead of the gasoline engine as the internal combustion engine. In that case, in order to fix the engine generated torque characteristics, a gas engine uses a butterfly valve that controls the amount of intake air,
In a diesel engine, the fuel injection amount may be controlled.

In the above embodiment, the capacitor 4 (capacitor) is used as the power storage device. However, the power storage device may be changed, and a flywheel type electric storage device capable of confirming the remaining energy and a remaining amount predicting function are provided. You may implement using a battery.

In the above embodiment, when controlling the engine output, the opening of the throttle valve is adjusted.
This configuration may be changed. For example, the engine output may be controlled by increasing or decreasing the fuel injection amount, or when the engine output is decreased, the supply of fuel may be stopped to reduce the generated torque of the engine to zero or less.

In the above embodiment, a series type electric vehicle is embodied, but as shown in FIG. 7, the present invention may be applied to a power split type electric vehicle. The electric vehicle shown in FIG. 7 has two motor generators (M / G) 2
1 and 22, both of which are supplied with power from the capacitor 23. The output shaft 21a of one motor generator 21 and the output shaft 24a of the engine 24 are connected. Output shaft 21 of each motor generator 21, 22
The driving forces a and 22 a are transmitted to the drive shaft 26 via the planetary differential gear 25. Similar effects can be obtained when the present invention is applied to this system.

In the above embodiment, the system controller 11 calculates the target rotational speed N0 based on the torque characteristic map in which the fuel efficiency of the engine 1 stored in the ROM 11a is optimal. May be stored, and the target rotation speed N0 may be calculated based on the torque characteristic map. Alternatively, a torque characteristic map with the optimum emission of the engine 1 may be stored in the ROM 11a, and the target rotation speed N0 may be calculated based on the torque characteristic map. Further, as a torque characteristic map to be stored in the ROM 11a, an optimal torque characteristic map for the fuel efficiency and noise, noise and emission, emission and fuel efficiency, or fuel efficiency and noise and emission is stored. The target rotation speed N0 may be calculated based on the stored torque characteristic map.

Although the embodiments of the present invention have been described above, technical ideas other than the claims that can be grasped from the above embodiments will be described below together with their effects. (A) The electric vehicle according to any one of claims 1 to 3, 4, and 5, wherein the generator is any one of a rotating armature type synchronous motor, an induction motor, and a DC motor. According to this configuration, it is possible to obtain the same operation and effect as the above embodiment.

(B) The electric vehicle according to any one of claims 1 to 6, wherein the driving force of the output shaft of the generator and the output shaft of the traveling motor is transmitted to the drive shaft via a gear. With the power split type electric vehicle having this configuration, the same operation and effect as those of the above embodiment can be obtained.

[0064]

As described above, according to the electric vehicle of the present invention, the engine can be used within a range suitable for the characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a serial-type electric vehicle according to an embodiment.

FIG. 2 is a block diagram of a converter according to one embodiment.

FIG. 3 is a torque characteristic diagram of an engine and a generator.

FIG. 4 is a torque characteristic diagram of an engine and a generator.

FIG. 5 is a characteristic diagram of a field current with respect to a rotation speed.

FIG. 6 is a generator control flowchart.

FIG. 7 is a schematic configuration diagram of another power split type electric vehicle.

FIG. 8 is a schematic configuration diagram of a charging portion of a conventional electric vehicle.

FIG. 9 is a torque characteristic diagram of a conventional engine and generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 2 ... Traveling motor, 3 ...
Generator: 4: Capacitor as power storage device, 7: Power generation control device, converter as control means, 9: Rotation sensor as rotation speed detection means, 11: Power generation control device, system controller as rotation speed calculation means, 12 ... Generator controller as power generation control device, field current calculation means, rotation speed comparison means

Claims (6)

[Claims] 1. An internal combustion engine, a generator connected to the internal combustion engine, driven to rotate by the internal combustion engine, and generating electric power according to a rotation speed driven based on a field control by a field current; A power storage device that stores power generated by the power storage device; a traveling motor that is driven to rotate based on the power supplied from the power storage device; and a device that rotates and drives the internal combustion engine based on optimal torque characteristics. The required power generation amount is calculated based on the running state, and the target rotation speed to control the generator corresponding to the power generation amount is calculated based on the generated power amount and the optimal torque characteristic of the internal combustion engine. Field control of the generator is performed based on the target rotation speed, and the generator is driven at a rotation speed at which a driving torque of the generator is balanced with a torque generated by rotation of the internal combustion engine. An electric vehicle that includes a power generation control device for rotational drive. 2. The power generation control device drives the internal combustion engine to rotate based on an optimal torque characteristic, and sets a target rotation speed of the generator corresponding to a required power generation amount based on a running state at each time. Rotation speed calculation means for calculating; rotation speed detection means for detecting the current rotation speed of the generator; comparison means for comparing the detected rotation speed of the generator with the target rotation speed; 2. The electric vehicle according to claim 1, comprising: a field current calculation unit that calculates a field current based on the field current; and a control unit that performs field control on a generator based on the field current. 3. 3. The field current calculating means increases the field current to decrease the number of revolutions of the generator when the number of revolutions is larger than a target number of revolutions, and the number of revolutions is reduced to a target number of revolutions. 3. The electric vehicle according to claim 1, wherein the field current is reduced when the field current is smaller than the field current. 4. The electric vehicle according to claim 1, wherein the generator is an internal magnet type electric motor. 5. The torque characteristic of the internal combustion engine is at least one of fuel efficiency, noise, and emission of the internal combustion engine.
The electric vehicle according to claim 1, wherein one of the electric vehicles has an optimal torque characteristic. 6. The driving condition includes at least one of a vehicle speed signal detecting a rotation speed of a driving motor, a voltage stored in the power storage device, an accelerator opening signal, and a brake operation position. 6. The method according to claim 1, wherein
An electric vehicle according to claim 1.