JP2001178198A - Generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation of high voltage by controlling the voltage generated in a generator employing both field windings and permanent magnets together, and to prevent consumption of unnecessary drive by the permanent magnets, in the case that the electrical load on the generator is only a motor, and shortened service life of the motor caused by the current always passing through the motor. SOLUTION: An H-bridge 13 is disposed to set the field current of the field winding 12 in the generator 1 to a negative value. In the case of generating high voltage, polarity switching is conducted to set the field current to a negative value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator for use in a motor vehicle, and more particularly to a device suitable for application to a drive device of a four-wheel (and more) drive vehicle using an electric motor.

[0002]

2. Description of the Related Art As shown in Japanese Patent Application Laid-Open No. H11-98787, a conventional generator is known in which permanent magnets are arranged between magnetic poles of a rotor to increase magnetomotive force and improve output. ing.

[0003]

In the above prior art, the output of the generator can be improved by the permanent magnet. On the contrary, the rotation speed given to the generator is high, and the electric load connected to the generator can be reduced. When it is small, there is a problem that the generated voltage cannot be controlled due to the magnetic flux generated by the permanent magnet, and a high voltage is generated.

As an application example of this generator, consider a case where an output terminal of the generator is always connected to the motor in an electric four-wheel drive vehicle in which front wheels are driven by an internal combustion engine and rear wheels are driven by a motor. Then, the generated voltage does not become zero due to the permanent magnet of the generator, and the voltage is constantly applied to the motor. 1) Unnecessary driving force is consumed. 2) The current always flows through the motor, and the life of the motor is extended. The problem of lowering occurs.

It is an object of the present invention to provide a generator control device which solves the above-mentioned problems.

[0006]

The object of the present invention is to provide an H-bridge so that the field current of the field winding of the generator can be set to a negative value. The problem can be solved by performing polarity switching such that is negative.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a part of the electric system of an automobile. Reference numeral 1 in FIG. 1 denotes a generator, a three-phase armature winding 11, a field winding 12 for supplying a magnetic flux to the armature winding 11, and the field winding 1.
H bridge 13 (PNP transistor 13
a, 13b, NPN transistors 13c, 13d), diodes 14a, 14b, 14c, 14d, a three-phase rectifier 15, a drive circuit 16 for driving the transistors of the H bridge 13, and a control circuit 17.

Reference numeral 2 denotes a motor, which is directly and electrically connected from a rectified output terminal of the generator 1. Reference numeral 3 denotes a battery which supplies power to an electric system (not shown) of the vehicle and is charged by another generator (not shown). 4,5
Is a wheel speed detector, the wheel speed detector 4 generates a pulse proportional to the rotation speed of the rear wheel, and the wheel speed detector 5 generates a pulse proportional to the rotation speed of the front wheel.

FIG. 2 is a diagram showing a mechanical arrangement state with respect to the drawing of FIG. The underlined numbers in FIG. 2 represent the same parts as those in FIG. 2 is a gasoline engine 101, 102a and 102b are front wheels, 103a and 1
03b is a rear wheel.

FIG. 3 is a sectional structural view of the generator 1 shown in FIG. The underlined numbers in FIG. 3 represent the same parts as those in FIG. 11a is a stator for supplying a magnetic flux to the armature winding 11, and 12a and 12b are rotors for exciting the field winding 12.

FIG. 4 is a structural view around the rotors 12a and 12b of FIG. The underlined numbers represent the same parts as in FIG. Reference numeral 12c denotes a permanent magnet containing a rare earth element, and supplies a magnetic flux to the rotors 12a and 12b. In particular, a magnetic flux in the same direction as the magnetic flux generated by the field winding 12 is generated,
The power output of the generator 1 can be increased.

In the above configuration, the operation of the control circuit 17 will be described with reference to the flowchart of FIG. Step 5 in FIG.
When the program is started at 01, the process proceeds to step 502. In step 502, the wheel speed detector 5 detects the front wheel rotation speed Nf. Next, at step 503, the wheel speed detector 4 detects the rotation speed Nr of the rear wheel. Further, at step 504, the difference ΔN between Nf and Nr is detected.

In accordance with the rotational speed difference ΔN, step 5
At step 05, the command value If of the field current of the generator is calculated. Here, PI (proportional-integral) control is performed.

If = K1 + K2 · ΔN + K3 · ∫ΔN dt (1) The following calculation is sequentially performed. Here, K1, K2, and K3 are constants. Command value If of field current calculated by equation (1)
Is large when the rotation speed Nr of the rear wheel is lower than the rotation speed Nf of the rear wheel.

Next, in step 506, it is determined whether If is positive or negative. If If is positive, the process proceeds to a step 507, where the transistor 13a is turned on via the drive circuit 16, the duty of the transistor 13d is calculated at a step 508, and the transistor 13d is set at a duty Dd via the drive circuit 16 at a step 509. ON / OFF control is performed by the conduction ratio. In this case, a "positive" field current flows through the field winding 12, generating a magnetic flux in the same direction as the permanent magnet 12c, and the power generation voltage of the generator 1 increases.

On the other hand, if it is determined in step 506 that If is negative, in step 510, the transistor 13b is turned on via the drive circuit 16, the duty of the transistor 13c is calculated in step 511, and the drive is performed in step 512. The transistor 13c is turned on / off via the circuit 16 at the duty ratio of the duty Dc. In this case, a “negative” field current flows through the field winding 12 to generate a magnetic flux in a direction opposite to that of the permanent magnet 12c, and the power generation voltage of the generator 1 decreases.

Upon completion of steps 509 and 512, the process returns to step 502. By repeating the above, generator 1
Is a positive value when the rotation of the rear wheel is delayed and a negative value when the rotation is advanced, and the feedback control is performed so that the rotation speeds of the front wheel and the rear wheel match.

In this embodiment, the circuit for controlling the field current of the generator 1 has an H bridge 13 (PNP transistor 13).
a, 13b, and NPN transistors 13c, 13d), the field current can flow in both positive and negative directions, so that the magnetic flux of the permanent magnet 12c can be canceled, and the power output of the generator 1 can be reduced to zero. It is possible to This makes it possible to completely match the rotational speeds of the front wheels and the rear wheels, and to prevent the wheels from slipping, so that the running stability of the vehicle is increased and the safety is enhanced.

Referring to FIG. 6, another embodiment of the present invention will be described. FIG. 6 shows a part of an electric system of an automobile. In FIG. 6, reference numeral 1 denotes a generator, which is a three-phase armature winding 11;
1, an H bridge 13 (PNP transistor 13a, connected to the field winding 12).
13b, NPN transistors 13c, 13d), diodes 14a, 14b, 14c, 14d, three-phase rectifier 1
5, a drive circuit 16 for driving the transistors of the H bridge 13.

Reference numeral 2 denotes an electric motor, which is electrically connected directly from the rectified output terminal of the generator 1, and includes a field winding 22 and an H bridge 23 (PNP transistors 23a and 23a).
b, NPN transistors 23c and 23d) and diodes 24a, 24b, 24c and 24d) and a drive circuit 26 for driving the transistors of the H bridge 23.

Reference numeral 3 denotes a battery which supplies power to an electric system (not shown) of the vehicle and is charged by 1 and another generator (not shown). Reference numerals 4a and 5a denote wheel speed detectors. The wheel speed detector 4a outputs the rotation speed of the rear wheel, and the wheel speed detector 5a outputs the rotation speed of the front wheel including information on the rotation direction. A control circuit 17a for controlling the H-bridge 13 of the generator 1 and the H-bridge 23 of the motor 2 is arranged outside the generator 1 and the motor 2.

The operation of the control circuit 17a in the configuration of FIG. 6 will be described with reference to the flowchart of FIG. When the program is started in step 701 of FIG. 7, the process proceeds to step 702. In step 702, the wheel speed detector 5 detects the front wheel rotation speed Nf. Next, at step 703, the rotation speed Nr of the rear wheel is detected by the wheel speed detector 4. Further, at step 704, the difference ΔN between Nf and Nr is detected.

According to the rotational speed difference ΔN, step 7
At step 05, the command value If of the field current of the generator is calculated. The same calculation as in the above-mentioned equation (1) is sequentially performed. Where K1, K
2 and K3 are constants. The command value If of the field current calculated by the equation (1) indicates that the rotation speed Nr of the rear wheel is equal to the rotation speed N of the rear wheel.
The value becomes larger when f is smaller than f.

Next, at step 706, it is determined whether If is positive or negative. If If is positive, the process proceeds to step 707, where the transistor 13a is turned on via the drive circuit 16, the duty of the transistor 13d is calculated at step 708, and the transistor 13d is set at the duty Dd via the drive circuit 16 at step 709. ON / OFF control is performed by the conduction ratio. In this case, a "positive" field current flows through the field winding 12, generating a magnetic flux in the same direction as the permanent magnet 12c, and the power generation voltage of the generator 1 increases.

On the other hand, if it is determined in step 706 that If is negative, in step 710, the transistor 13b is turned on via the drive circuit 16, and in step 711, the duty of the transistor 13c is calculated. The transistor 13c is turned on / off via the circuit 16 at the duty ratio of the duty Dc. In this case, a “negative” field current flows through the field winding 12 to generate a magnetic flux in a direction opposite to that of the permanent magnet 12c, and the power generation voltage of the generator 1 decreases.

When steps 709 and 712 are completed, the process proceeds to step 713. In step 713, the rotation direction of the front wheel is detected. In the case of normal rotation, that is, in the case of Nf> 0, the process proceeds to step 714, where the transistor 2 of the H bridge 23
3a and 23b are turned on, and a field current is applied so that the rear wheel also rotates forward.

On the other hand, when the front wheels are rotating in the reverse direction,
If f <0, the process proceeds to step 715, where the H bridge 23
The transistors 23b and 23c are turned ON, and a field current is applied so that the rear wheels also rotate in the reverse direction. After the rotation direction of the rear wheel is determined, the process returns to step 702. Repeat the above,
The field current of the generator 1 has a positive value when the rotation of the rear wheel is delayed, and has a negative value when the rotation is advanced, and the feedback control is performed so that the rotation speeds of the front wheel and the rear wheel match.

The circuit diagram of FIG. 6 is different from that of FIG. 1 in that the field current of the electric motor 2 can be switched in both positive and negative directions, and the rear wheels 103b and 104b can rotate forward and reverse, and not only move forward. It is possible to prevent the wheels from slipping during retreat.

[0029]

As described above, according to the present invention, the problem that the generated voltage cannot be controlled due to the magnetic flux generated by the permanent magnet of the generator and the high voltage is generated is solved. In particular, in an electric four-wheel drive vehicle, considering the case where the output terminal of the generator is always connected to the motor, unnecessary driving force is consumed and the fuel consumption rate can be reduced. This has the effect of preventing current from constantly flowing in the motor and prolonging the life of the motor.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a part of an electric system of an automobile according to an embodiment of the present invention.

FIG. 2 is a view showing a mechanical arrangement state with respect to the drawing of FIG. 1;

FIG. 3 is a sectional structural view of the generator 1 of FIG.

FIG. 4 is a structural diagram around the rotors 12a and 12b of FIG.

FIG. 5 is a flowchart illustrating an operation of a control circuit 17 of FIG. 1;

FIG. 6 is a circuit diagram showing a part of an electric system of an automobile according to another embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of the control circuit 17a of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Motor, 4, 5 ... Wheel speed detector, 12
... field winding, 13 ... H bridge, 101 ... gasoline engine.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 21/04 B60K 9/00 E (72) Inventor Tatsuyuki Yamamoto 2520 No. Daiba Takaba, Hitachinaka-shi, Ibaraki Pref. Hitachi, Ltd. Automotive Equipment Group (72) Inventor Yuji Maeda, Hitachi, Ibaraki Prefecture, 2520 Oji Takaba, Ltd. Hitachi, Ltd. Automotive Equipment Group (72) Inventor Susumu Tajima, Hitachi, Ibaraki Prefecture, 2520 Oji Takaba Co., Ltd. (72) Inventor West Building Keisuke Ibaraki Pref. QN23 RB19 RB20 SE02 SE03 TB03 5H590 AA02 AA30 AB01 CA07 CA23 CC04 CD01 CD10 CE04 DD25 EB11 EB12 FA08 FB03 FC12 HA27 JA02 JA12 JA13 5H619 AA00 AA13 BB02 BB06 BB10 BB18 PP35 5H621 BB07 BB10 HH01

Claims (3)

[Claims] An armature winding for generating an electromotive force by a magnetic flux generated from both a field winding and a permanent magnet, a rectifier for rectifying an AC voltage generated in the armature winding, and an output of the rectifier. A generator comprising a voltage adjusting device for detecting a voltage and adjusting a current flowing through the field winding, and a generator which is driven by the internal combustion engine and outputs electric energy for driving an actuator of the vehicle. An H-bridge circuit connected to both ends of the field winding, and a control device for controlling an output voltage of the generator according to a required driving force from the vehicle, wherein an output voltage of the rectifier is higher than a required value. When the power is high, a negative field current is supplied by the H-bridge circuit, and control is performed so as to cancel the magnetic flux generated by the permanent magnet. 2. The generator according to claim 1, wherein the actuator is an electric motor, and drives an axle different from the internal combustion engine. 3. An internal combustion engine that drives a first drive shaft of a vehicle, and an armature winding that is driven by the internal combustion engine and generates an electromotive force by a magnetic flux generated from both a field winding and a permanent magnet. A vehicle having a generator comprising a rectifier for rectifying an AC voltage generated in the armature winding, and an electric motor receiving electric energy from the generator and driving a second drive shaft of the vehicle; Excitation by the H-bridge circuits 13 (13a, 13b, 13c, 13d) connected to both ends of the field winding according to the difference between the driving force of the first driving shaft and the driving force of the first driving shaft. A vehicle comprising a control device for controlling a polarity and a current.