JP3946648B2 - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a hybrid vehicle which can perform demagnetization, while protecting stator windings that a generator-motor possesses, without needing external devices. <P>SOLUTION: This controller for a hybrid vehicle, which is equipped with an engine for outputting the driving force by driving the drive shaft of a vehicle; a generator motor having a permanent magnet type rotor for rotating the drive shaft, according to the operation state of the vehicle, and generating the regenerative energy by the regenerative action, at the deceleration of the vehicle and the generating energy by the output of the engine, an energy storage device for accumulating the generating energy and the regenerative energy and also supplying electric energy to the generator motor, and an inverter for adjusting the quantity of supply of the electric energy supplied from the energy storage device to the generator motor, is equipped with a demagnetizing operation mode where it suppresses the output torque of the motor, while keeping the engine at high revolution. <P>COPYRIGHT: (C)2004,JPO&amp;NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid vehicle including an engine and a motor as a vehicle drive source.
[0002]
[Prior art]
In recent years, hybrid vehicles using an engine and a motor capable of generating electric power as power sources have been developed for the purpose of saving fuel for driving the engine and reducing exhaust gas generated by fuel combustion.
In this type of hybrid vehicle, the power input from the wheels when the vehicle is decelerated is transmitted to the motor, the regenerative operation is performed by the motor, the deceleration energy is converted into regenerative energy, and the power storage device is charged as electrical energy. That is often used.
[0003]
By the way, a permanent magnet is mounted on the motor, and its magnetic force is very strong in terms of performance required for the motor. Accordingly, when performing the process of removing the magnet from the motor, etc., it is desirable to perform a demagnetization process that demagnetizes the magnetic force because the magnetic force of the magnet becomes an obstacle to the process.
As a technique for demagnetizing such a magnet, there has been proposed a device for demagnetizing a magnet by applying a high-frequency voltage between terminals of a motor winding (see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-346364
[Problems to be solved by the invention]
However, in the above-described conventional technology, when performing the demagnetization process, it is necessary to attach and detach the demagnetizing device, which increases the work load and requires a work space for installing the demagnetizing device. The place where magnetic processing can be performed is limited. In addition, when a power storage device of a vehicle is used as a power source for applying a high-frequency voltage, there is a problem that power required for starting the vehicle may be consumed from the power storage device.
Moreover, as a method of demagnetizing the magnet, there is a method of demagnetizing by heating the magnet to a predetermined temperature (Curie temperature). However, if the entire motor is heated, there is a risk of damaging the stator windings provided in the motor. There was a problem that it was not preferable.
[0006]
The present invention has been made in view of such circumstances, and provides a control device for a hybrid vehicle that does not require an external device and can perform demagnetization processing while protecting a stator winding included in a generator motor. The purpose is to do.
[0007]
[Means for Solving the Problems]
The invention described in claim 1 made to solve the above problems drives a drive shaft (for example, a drive shaft 8 in an embodiment described later) of a vehicle (for example, a vehicle 1 in an embodiment described later). An engine (for example, an engine 2 in an embodiment to be described later) that outputs a propulsive force, and the drive shaft is driven to rotate according to the driving state of the vehicle, and the regenerative energy by the regenerative operation at the time of deceleration of the vehicle and the A generator motor (for example, a motor 3 in an embodiment to be described later) having a permanent magnet rotor (for example, a rotor 15 in an embodiment to be described later) that generates power generation energy by the output of the engine, the generated energy and the regenerative energy And a power storage device that supplies electrical energy to the generator motor (for example, in the embodiments described later) A battery 7) that the power storage device said inverter to adjust the supply amount of the electrical energy supplied to the generator motor (e.g. from the control apparatus for a hybrid vehicle having an inverter 6) in the embodiment described below, the engine A demagnetization operation mode for controlling the output torque of the generator motor to be zero or a negative value in the vicinity thereof while maintaining the rotation speed of the engine at a predetermined rotation speed or more, and further driving the engine during the demagnetization operation mode. Means is provided for holding the transmission in an unconnected state from the shaft .
[0008]
According to this invention, when performing the demagnetization process of the magnet included in the rotor, the torque is transmitted from the engine by suppressing the output torque of the generator motor while switching to the demagnetization operation mode and maintaining the engine at a high speed. Since the rotational energy is converted into thermal energy, the magnet is heated and its magnetic force is demagnetized. In the demagnetization operation mode, most of the rotational energy is converted into heat energy and hardly converted into power generation energy, so that the temperature increase of the stator winding accompanying power generation can be suppressed and fixed. It is possible to perform demagnetization while protecting the child winding. In addition, since the demagnetizing process is performed by the driving force of the engine, it is not necessary to use a demagnetizing device, and it is not necessary to attach or remove the demagnetizing device, and the installation space for the demagnetizing device is also unnecessary, so the work load is reduced. It can be reduced and the work space can be reduced.
[0009]
Further, if the demagnetization operation mode is set in a region where the output torque of the generator motor is negative, regenerative energy is generated slightly from the generator motor, so that the power can be supplied to the power storage device. The demagnetization process can be performed even when the amount of stored electricity is low.
[0010]
In addition, since the transmission is not transmitted to the wheels by holding the transmission in a disconnected state from the engine drive shaft, the drive force can be effectively used for the demagnetization processing of the generator motor. The efficiency of magnetic processing can be increased.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a control apparatus for a hybrid vehicle according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a control apparatus for a hybrid vehicle in an embodiment of the present invention. The hybrid vehicle according to the present embodiment includes, for example, an internal combustion engine 2 that generates driving force by burning gasoline, a motor 3 that can assist the output of the engine 2 or generate driving force alone, and a flywheel. A clutch mechanism 4 including the transmission mechanism 5 and a transmission 5 that transmits a driving force generated by the internal combustion engine 2 and the motor 3 to a driving shaft (crankshaft).
[0012]
The motor 3 is a three-phase AC synchronous motor 3 that assists the output of the engine 2 during acceleration and the like, and exhibits a regenerative braking function to charge the battery 7 during deceleration of the vehicle. The inverter 6 converts the output voltage (DC) of the battery 7 into an AC voltage and supplies it to each phase of the AC motor 3.
[0013]
FIG. 2 is a schematic perspective view showing a stator of a motor provided in the hybrid vehicle.
The stator 10 includes a plurality of teeth iron cores 11 arranged radially on a predetermined circumference at predetermined intervals, and a core back iron core 12 arranged between adjacent tooth iron cores 11 and 11. The teeth iron core 11 and the core back iron core 12 are formed by laminating electromagnetic steel plates having directionality such as silicon steel plates. A stator winding 13 is wound around an inner peripheral side surface between the teeth cores 11.
[0014]
FIG. 3 is a schematic perspective view showing a rotor of a motor provided in the hybrid vehicle.
The iron core of the rotor 15 is configured by laminating a plurality of plates made of, for example, steel plates, and a plurality of magnets 16 are interposed at predetermined intervals in the circumferential direction.
[0015]
FIG. 4 is an explanatory view showing a state in which the electric motor including the stator 10 according to the embodiment of the present invention is attached to the engine. As shown in the figure, the stator 10 of the motor 3 is attached to the engine 2 via the outer peripheral holding ring 9. The rotor 15 is formed by mounting a magnet 16 on the outer peripheral portion of a drive plate provided between the crankshaft 21 and the transmission 5 of the engine 2 in a state of facing the stator 10 in the radial direction. . In addition, the attachment position of this stator 10 is an example, and it is needless to say that it may be attached to another position.
[0016]
FIG. 5 is a flowchart showing demagnetization control in the hybrid vehicle of FIG. First, in step S12, it is determined whether or not the magnet 16 of the rotor 15 needs to be exchanged. For example, if the determination result is YES, the process proceeds to step S14. If the result is NO, the determination process is performed again. Therefore, if it is not determined to be the demagnetization mode, the following series of processing is not performed.
[0017]
If it is determined that the demagnetization mode is selected, high rotation control of the engine 2 is started in step S14. Here, in the case of a hybrid vehicle in which the motor 3 and the engine 2 can be separated, the motor 3 and the engine 2 are engaged so that the driving force of the engine 2 can be transmitted to the motor 3.
[0018]
Next, in step S16, it is determined whether or not the rotational speed of the engine 2 (the number of rotations per unit time) is greater than the predetermined number of rotations Nref. If the determination result is YES, the process proceeds to step S18, where the determination result is If NO, the process of step S14 is performed again. In the present embodiment, since the engine 2 and the rotor 15 of the motor 3 are directly connected, the rotational speed of the engine 2 becomes the rotational speed of the motor 3 (the rotational speed of the rotor 15).
[0019]
FIG. 6 is a graph showing the relationship between the torque of the motor 3 (rotor 15) and the rotational speed. As shown in the figure, since the rotational speed N of the rotor 15 and the output torque Tq are in an inversely proportional relationship, increasing the rotational speed of the rotor 15 above the predetermined rotational speed Nref increases the output torque Tq. The thickness can be suppressed within a predetermined range.
[0020]
In step S18, a timer for measuring the demagnetization time is started, and the process proceeds to step S20. In step S20, the rotor 15 is controlled so that the rotational speed N and the torque Tq of the rotor 15 are maintained within the range of the region A. That is, while maintaining the rotational speed of the rotor 15 at a predetermined rotational speed (for example, Nref) or higher, the output torque Tq is controlled to be 0 or a negative value in the vicinity thereof (0 torque control).
By controlling in this way, most of the rotational energy transmitted from the engine 2 is converted into thermal energy, so that the magnet 16 is heated.
[0021]
At this time, since the demagnetization process is performed by setting the rotation speed of the rotor 15 to a high rotation (Nref or higher), the magnet 16 can be demagnetized while protecting the stator winding 13 of the motor 3. it can. This will be described with reference to FIGS.
FIGS. 7 and 8 are graphs showing temperature changes of the magnet 16 and the stator winding 13 when the rotation speed of the rotor 15 is high (Nref or higher) and low (less than Nref), respectively. In these drawings, Tc represents a temperature at which the magnet 16 is sufficiently demagnetized (Curie temperature), and Slmt represents a durable temperature of the stator winding 13.
[0022]
When the rotational speed of the rotor 15 is low, the output torque Tq is large (see FIG. 6). At this time, the rotational energy transmitted from the engine 2 is almost converted into electric energy and transmitted to the magnet 16. Heat energy is lost. Therefore, as shown in FIG. 8, the temperature J2 of the magnet 16 is restrained from increasing, and the stator winding 13 generates heat as electric energy is transmitted, so that the temperature S2 increases. If the temperature S2 of the stator winding 13 exceeds the durable temperature Slmt, the reliability of the stator winding 13 may be impaired.
[0023]
On the other hand, when the rotational speed of the rotor 15 is high, the output torque Tq is small (see FIG. 6). At this time, the rotational energy transmitted from the engine 2 is hardly converted into electric energy. Most of the energy can be transferred to the magnet 16 as thermal energy. Accordingly, as shown in FIG. 7, the temperature J1 of the magnet 16 rises due to the transmitted thermal energy. Therefore, by continuing the zero torque control, the magnet 16 can be heated until the temperature J1 of the magnet 16 becomes equal to or higher than the Curie temperature Tc, and thus the magnetic force can be demagnetized.
[0024]
Further, since the rotational energy is hardly converted into generated energy, an increase in the temperature S2 of the stator winding 13 due to power generation can be suppressed, and the temperature S2 can be suppressed within the durable temperature Slmt. Accordingly, the magnet 16 can be demagnetized while protecting the stator winding 13.
[0025]
In step S22, it is determined whether the time required for the demagnetization process has elapsed (whether the timer has expired). If the determination result is YES, the process proceeds to step S24, and if the determination result is NO Returns to step S20 and continues zero torque control.
In step S24, the high rotation control of the engine 2 is stopped, and the process proceeds to step S26. In step S26, the zero torque control of the motor 3 is stopped, and the series of demagnetization processes is terminated.
[0026]
In this way, it is possible to perform demagnetization processing of the magnet 16 while protecting the stator winding 13. In addition, since the demagnetizing process is performed by the driving force of the engine 2, it is not necessary to use a demagnetizing device, and it is not necessary to attach or detach the demagnetizing device. And the work space can be reduced.
[0027]
In the present embodiment, since the demagnetization operation mode is set in a region where the output torque of the rotor 15 is negative, a small amount of regenerative energy is generated from the motor 3. The electric power can be supplied, and the demagnetization process can be performed even when the amount of power stored in the battery 7 is low.
[0028]
Further, when the demagnetization process is performed, the transmission 5 is kept from being disconnected from the engine drive shaft 8 so that the drive force of the engine 2 is not transmitted to the wheels. It can be used effectively for magnetic processing, and the efficiency of demagnetization processing can be increased.
[0029]
【The invention's effect】
As described above, according to the invention described in claim 1, it is not necessary to use a demagnetizing device, and the work for attaching and detaching the demagnetizing device is unnecessary, and the installation space for the demagnetizing device is also unnecessary. The work load can be reduced and the work space can be reduced. The demagnetization process can be performed while protecting the stator windings of the generator motor.
[0030]
In addition, since the transmission is not transmitted to the wheels by holding the transmission in a disconnected state from the engine drive shaft, the drive force can be effectively used for the demagnetization processing of the generator motor. The efficiency of magnetic processing can be increased.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an outline of a hybrid vehicle to which a hybrid vehicle control device according to an embodiment of the present invention is applied.
2 is a schematic perspective view showing a stator of a motor provided in the hybrid vehicle of FIG. 1. FIG.
3 is a schematic perspective view showing a rotor of a motor provided in the hybrid vehicle of FIG. 1. FIG.
4 is an explanatory diagram showing a state in which the motor of the hybrid vehicle of FIG. 1 is attached to an engine. FIG.
FIG. 5 is a flowchart showing demagnetization control in the hybrid vehicle of FIG. 1;
6 is a graph showing the relationship between the torque and the rotational speed of the motor of FIG.
FIG. 7 is a graph showing temperature changes of a magnet and a stator winding when the rotation speed of the rotor is high.
FIG. 8 is a graph showing a temperature change of a magnet and a stator winding when the rotational speed of the rotor is high.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Engine 3 Motor 5 Transmission 6 Inverter 7 Battery 10 Stator 16 Magnet

Claims (1)

An engine that drives the drive shaft of the vehicle to output a propulsive force, and the drive shaft is driven to rotate according to the driving state of the vehicle, and the regenerative energy by the regenerative operation during deceleration of the vehicle and the power generation by the output of the engine A generator motor having a permanent magnet rotor for generating energy; a power storage device for storing the generated energy and the regenerative energy and supplying electric energy to the generator motor; and the power supplied from the power storage device to the generator motor the control apparatus of the hybrid vehicle having an inverter for adjusting the supply of electrical energy, so that the rotational speed of the engine to a negative value of zero or near the output torque of the generator motor while maintaining the predetermined rotational speed or more A demagnetization operation mode to control, and further from the engine drive shaft during the demagnetization operation mode Control apparatus for a hybrid vehicle, characterized by comprising means for holding the speed machine in a non-connected state.

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