JP2009196533A - Dynamo-electric machine control system and vehicle driving system having the dynamo-electric machine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamo-electric machine control system allowing a dynamo-electric machine to generate torque allowing execution of AMD (active motor damping) control in ABS (anti-lock brake system) operation, and allowing suppression of voltage fluctuation on an output side of a booster circuit in the AMD control. <P>SOLUTION: This dynamo-electric machine control system has: a DC power supply; the dynamo-electric machine for driving a vehicle; a frequency conversion part interposed between the DC power supply and the dynamo-electric machine; a voltage conversion part interposed between the DC power supply and the frequency conversion part, and boosting output of the DC power supply based on a boosting instruction value set according to target torque of the dynamo-electric machine; and a control part controlling the frequency conversion part and the voltage conversion part, and performing active-motor-damping control in operation of an anti-lock brake system of the vehicle. The control part sets the boosting instruction value to a prescribed in-AMD boosting instruction value VF regardless of the target torque in the execution of the active-motor-damping control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine control system that controls the rotating electrical machine of a vehicle that includes the rotating electrical machine as a drive source. The present invention also relates to a vehicle drive system provided with the rotating electrical machine control system.

  In recent years, attempts to reduce the environmental burden due to consumption of fossil fuels have been widely carried out. In the industry as well, automobiles that have a smaller environmental load than automobiles driven by internal combustion engines have been proposed. An example is an electric vehicle driven by an electric motor that is a rotating electric machine, and a hybrid vehicle driven by an internal combustion engine and an electric motor. An electric motor mounted in an electric vehicle or a hybrid vehicle is expected to exhibit a good torque suitable for passenger driving over a wide speed range (rotational speed range).

  An electric motor as a rotating electrical machine (motor or generator) operates on the principle of generating a force (torque) by a magnetic field and an electric current. However, when the electric motor is rotating, a force acts in the magnetic field, and so-called back electromotive force is generated. Since the back electromotive force is generated in a direction that hinders the flow of current that generates torque, the current that flows in the magnetic field to rotate the electric motor decreases, and the force (torque) decreases. As the rotational speed of the electric motor increases, the counter electromotive force also increases. Therefore, when the rotational speed reaches a certain value, the current generated by the counter electromotive force reaches the drive current, and the electric motor cannot be controlled. Accordingly, “field weakening control” is performed in which the field force that generates the magnetic field is weakened and the generation of the counter electromotive force is suppressed. However, when field-weakening control is performed, the field strength is weakened to reduce the strength of the magnetic field, and the maximum torque obtained is reduced. In Patent Document 1 showing the source below, a decrease in efficiency due to an increase in loss is pointed out.

  In response to this problem, Patent Document 1 proposes a technique for boosting the voltage of a battery that supplies driving electric power to an electric motor and shifting the rotational speed to shift to field-weakening control to a higher rotational speed. According to this technique, the voltage of the battery is boosted by the booster circuit (converter) in accordance with the position of the target operating point of the electric motor set by the torque and the rotational speed. This makes it possible to shift the region for performing field-weakening control to the high output side (high rotational speed side). In the example described in Patent Document 1, the field of normal field control (generally maximum torque control) in which field-weakening control is not performed is expanded step by step by setting a plurality of boosted voltage values.

  On the other hand, regardless of the driving method, when the vehicle is suddenly braked, the wheel may be locked, so that the braking distance may be increased or the steering performance may be impaired. In contrast, an increasing number of vehicles are equipped with anti-lock brake systems (ABS). During the operation of the ABS, the locked state and the unlocked state of the wheel are repeated in a short cycle, so that rapid cycle vibration occurs. When combined with the inertia of an electric motor in which this cycle vibration is largely reflected, the drive system such as a trans-axle may bend and cause damage.

  On the other hand, in Patent Document 2, which is cited below, the active vibration that actively attenuates the vibration of the drive system caused by the deflection of the drive system due to the inertia of the electric motor during the ABS operation is controlled by the control of the electric motor.・ A technology called active motor damping (AMD) has been proposed. AMD is the difference between the speed of the electric motor and the average wheel speed, the angular acceleration of the electric motor, the average of the angular acceleration of the wheel, the difference between the angular acceleration of the electric motor and the average angular acceleration of the wheel, and combinations of these factors. This is accomplished by generating a motor torque proportional to at least one.

JP-A-10-66383 (3rd to 12th paragraphs, FIGS. 1 and 2 etc.) JP 2006-51929 A (pages 4-5)

  By the way, in order to improve the efficiency of an electric motor, motor control using a converter (boost circuit) as described in Patent Document 1 and AMD control described in Patent Document 2 may be used in combination. As described above, the value of the boosted voltage by the converter is set so that maximum torque control can be performed without excess or deficiency at the required target operating point. In the AMD control, in order to generate a torque for actively attenuating the intense vibration at the time of ABS operation, it is necessary to fluctuate the boost voltage as the target operating point fluctuates. However, there is a time lag when the boost command value is changed and the converter actually follows. Therefore, an unnecessarily high voltage may be applied when the boosted voltage changes from the high side to the low side, or conversely, a voltage shortage may occur when the boosted voltage changes from the low side to the high side.

  Further, as exemplified in FIG. 1 of Patent Document 2, the hybrid vehicle includes a plurality of electric motors, and at least one electric motor can charge a battery with energy generated by the internal combustion engine. Some machines adopt a split method that can be used as a machine. In this case, regenerative power is supplied to the battery side from the electric motor that functions as a generator by the rotation of the wheels. At this time, the converter functions as a regenerative circuit or a step-down circuit as necessary. When AMD control is applied to such a split type hybrid vehicle and the operation of the electric motor is frequently switched between power running and regeneration, the converter is also frequently switched between boost operation and regeneration operation. Become. As is well known, a converter has a switching element that is the core during boost operation and a switching element that is the core during regenerative operation, with the positive side and negative side (in many cases ground) of the output after boosting. They are connected in series. When the converter switches from boost operation to regenerative operation, both switching elements include the transition time so that the series circuit of the switching elements is both turned on and the positive and negative sides of the converter output are not short-circuited. The dead time when both are turned off is set. During the dead time period, power regeneration to the battery cannot be performed, so that the generated power is stored in a smoothing capacitor connected in parallel on the output side of the converter. When the amount of power generation is large, the potential on the output side of the converter rises and may exceed the allowable voltage of the control circuit, such as a smoothing capacitor, converter, or inverter for AC conversion connected at the subsequent stage of the converter.

  The present invention was devised in view of the above-described problem related to a rotating electrical machine control system including a booster circuit. The rotating electrical machine can generate torque capable of performing AMD control at the time of ABS operation. An object of the present invention is to provide a rotating electrical machine control system capable of suppressing voltage fluctuation on the output side.

In order to achieve the above object, the characteristic configuration of the rotating electrical machine control system according to the present invention is as follows:
DC power supply,
A rotating electric machine for driving the vehicle;
It is interposed between the DC power supply and the rotating electrical machine, converts the output of the DC power supply to alternating current when the rotating electrical machine is powering, and converts the output from the rotating electrical machine to direct current when the rotating electrical machine is regenerated. A frequency converter to convert;
A voltage converter that is interposed between the DC power supply and the frequency converter and boosts the output of the DC power supply based on a boost command value set according to a target torque of the rotating electrical machine;
An active motor that controls the frequency conversion unit and the voltage conversion unit to generate torque in the rotating electrical machine in a direction that suppresses vibration of the vehicle drive system that is generated when the anti-lock brake system of the vehicle is operated. A rotating electrical machine control system including a control unit that performs damping control,
The controller is configured to set the boost command value to a constant AMD boost command value regardless of the target torque when the active motor damping control is executed.

  According to this characteristic configuration, when executing active motor damping control, the boost command value is set to a constant AMD boost command value regardless of the target torque. Therefore, even if the target torque determined according to the torque and the rotational speed of the rotating electrical machine is switched in a short time by the active motor damping control, the boost command value for realizing the target torque remains constant without fluctuation. It becomes the value of. Therefore, the output of the voltage converter does not change following the fluctuating boost command value. As a result, there is no time lag that occurs when the output of the voltage converter follows the boost command value, and the actual voltage on the output side of the voltage converter becomes excessive or low with respect to the boost command value. Inconsistencies are suppressed. That is, it is possible to provide a rotating electrical machine control system that can suppress voltage fluctuation on the output side of the booster circuit during active motor damping control.

  Further, the boost command value at the time of AMD of the rotating electrical machine control system according to the present invention is such that the rotating electrical machine operates within the maximum number of rotations of the rotating electrical machine that performs the active motor damping control. It is preferable that the predetermined maximum torque for AMD for damping control is set to a value that can be output in both positive and negative directions.

  When the boost command value during AMD is set in this way, the rotating electrical machine can output the torque that can execute the active motor damping control when the anti-lock brake system is operated without any shortage.

  Further, the AMD boost command value of the rotating electrical machine control system according to the present invention is such that the difference between the allowable voltage of the voltage converter and the frequency converter and the AMD boost command value is determined by the rotating electrical machine being the active motor. It is preferable that the value is set so as to be larger than the amplitude value of the voltage fluctuation generated on the DC side of the frequency converter when the damping control is performed.

  As described above, the output voltage of the voltage converter may exceed the allowable voltage of the voltage converter and the frequency converter. The difference between the allowable voltage of the voltage conversion unit and the frequency conversion unit and the boost command value during AMD is appropriately increased by the voltage conversion unit based on the boost command value. It is almost equal to the difference from voltage. If this difference is larger than the amplitude value of the voltage fluctuation (value from the center of amplitude to one of the wave heights) generated on the DC side of the frequency converter when the rotary electric machine is controlled by active motor damping, the frequency converter The voltage on the DC side (the output side of the voltage converter) does not exceed the allowable voltage. Therefore, it is possible to provide a rotating electrical machine control system that can suppress an overvoltage on the output side of the booster circuit during AMD control.

  Further, it is preferable that the AMD boost command value in the rotating electrical machine control system according to the present invention is set to a value lower than a maximum value of the boost command value set according to the target torque.

  When the boost voltage command value is the maximum value, the difference between the output of the voltage converter and the allowable voltage of the voltage converter and the frequency converter is the smallest. In this state, if voltage fluctuation occurs on the output side of the voltage converter, the allowable voltage may be exceeded. However, when the AMD boost command value is set to a value lower than the maximum value of the normal boost command value set according to the target torque, the difference between the output of the voltage converter and the allowable voltage widens. Therefore, the possibility of exceeding the allowable voltage due to voltage fluctuation is suppressed.

  Further, the rotating electrical machine control system according to the present invention is based on the difference between the wheel speed and the rotational speed of the rotating electrical machine converted by the control unit in the common shaft of the vehicle drive system. It is preferable to calculate a torque in a direction to reduce the difference as the target torque to be generated by the rotating electrical machine when performing the damping control.

  According to this configuration, the torque in the direction of reducing the difference between the wheel speed and the rotation speed of the rotating electrical machine is calculated as the target torque. Thereby, the vibration of the drive system of a vehicle can be suppressed suitably.

A vehicle drive system according to the present invention includes the above-described rotating electrical machine control system according to the present invention, and
The rotating electrical machine includes a first rotating electrical machine and a second rotating electrical machine,
A power distribution mechanism that distributes a driving force generated from a driving source other than the first rotating electric machine and the second rotating electric machine, wherein one driving force distributed by the power distributing mechanism is applied to a wheel, and the other driving force; Is transmitted to the first rotating electrical machine, and the driving force generated by the second rotating electrical machine is transmitted to the wheels.

  The vehicle drive system with this configuration can realize a hybrid vehicle that includes a pair of rotating electric machines and a drive source (for example, an engine) other than the pair of rotating electric machines and performs so-called split-type power distribution. And the said hybrid vehicle implement | achieves the driving | operation of a pair of rotary electric machine in the form which satisfy | fills the rotation speed and torque which are requested | required of those rotary electric machines, and also by each of a pair of rotary electric machine by a single voltage conversion part A system that obtains the required voltage can be easily realized.

The vehicle drive system of the present invention includes:
The power distribution mechanism is configured to include a planetary gear mechanism having a first rotation element, a second rotation element, and a third rotation element in order of rotational speed,
The first rotating electrical machine is connected to the first rotating element, a drive source other than the rotating electrical machine is connected to the second rotating element, and the second rotating electrical machine and the third rotating element are connected to wheels. A configuration is preferred.

  By adopting this structure, it is possible to easily realize a hybrid vehicle that performs split-type power distribution using a single planetary gear mechanism.

  Hereinafter, an embodiment of a rotating electrical machine control system according to the present invention will be described with reference to the drawings. The rotating electrical machine control system is incorporated in a vehicle drive system and serves for operation control of the rotating electrical machine provided in the vehicle drive system. FIG. 1 is a block diagram schematically showing the configuration of a drive system of a vehicle drive system 200, and FIG. 2 is a rotary electric machine mainly including a rotary electric machine drive device In provided for controlling the rotary electric machines MG1 and MG2. It is a block diagram which shows typically the structure of a control system. FIG. 3 is a block diagram schematically showing the configuration of the drive system of the vehicle drive system 200 centering on the wheels W and the brake 30.

  As shown in FIGS. 1 and 3, the vehicle includes an engine E that is an internal combustion engine and a pair of rotating electrical machines MG1 and MG2. The vehicle drive system 200 is a so-called hybrid system, and includes the hybrid drive device 1 between the engine E and the wheels W. As the engine E, various known internal combustion engines such as a gasoline engine and a diesel engine can be used. As will be described later, each of the rotating electrical machines MG1 and MG2 operates as a motor (electric motor) or a generator (generator). Accordingly, in the following description, reference numerals MG1 and MG2 may be omitted unless it is particularly necessary to specify any rotating electrical machine. The vehicle can travel by obtaining a driving force from the engine E or a rotating electrical machine acting as a motor. Further, at least a part of the driving force generated by the engine E is converted into electric power in the rotating electrical machine that functions as a generator, and is used for charging the battery B or driving the rotating electrical machine that functions as a motor. Furthermore, at the time of braking, it is also possible to regenerate electric power to the battery B by generating electric power with the rotating electrical machine using the braking force.

  The input shaft I of the hybrid drive device 1 is connected to an output rotation shaft such as a crankshaft of the engine E. A configuration in which the input shaft I is connected to the output rotation shaft of the engine E via a damper, a clutch, or the like is also suitable. The output of the hybrid drive device 1 is transmitted to the wheels W via the differential device D and the like. Further, the input shaft I is coupled to the carrier ca of the power distribution mechanism P1, and the intermediate shaft M connected to the wheels W via the differential device D is coupled to the ring gear r.

  The first rotating electrical machine MG1 includes a stator St1 and a rotor Ro1 that is rotatably supported on the radially inner side of the stator St1. The rotor Ro1 of the first rotating electrical machine MG1 is connected to rotate integrally with the sun gear s of the power distribution mechanism P1. The second rotating electrical machine MG2 includes a stator St2 and a rotor Ro2 that is rotatably supported on the radially inner side of the stator St2. The rotor Ro2 of the second rotating electrical machine MG2 is coupled to rotate integrally with the output gear O, and is connected to the input side of the differential device D.

  The first rotating electrical machine MG1 and the second rotating electrical machine MG2 are electrically connected to the battery B via the rotating electrical machine drive device (inverter device) In, as shown in FIG. Each of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 functions as a motor (electric motor) that generates power by receiving power supply and a generator (generator) that generates power by receiving power supply. It is configured to be able to perform functions.

  In the configuration example in the present embodiment, the first rotating electrical machine MG1 functions as a generator that generates power mainly by the driving force input via the sun gear s of the power distribution mechanism P1, and charges the battery B or the second Electric power for driving the rotating electrical machine MG2 is supplied. However, the first rotating electrical machine MG1 may function as a motor when the vehicle is traveling at high speed. On the other hand, the second rotating electrical machine MG2 mainly functions as a motor that assists the driving force for traveling the vehicle. Further, when the vehicle is decelerated, the second rotating electrical machine MG2 functions as a generator that regenerates the inertial force of the vehicle as electric energy. Such operations of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 are controlled by a TCU (trans-axle control unit) 10 (see FIG. 2). The TCU 10 functions as a control unit of the present invention, and controls the rotating electrical machines MG1 and MG2 via the rotating electrical machine drive device In including the voltage conversion unit 4 and the frequency conversion unit 5 as described later.

  As shown in FIG. 1, the power distribution mechanism P <b> 1 is configured by a single pinion type planetary gear mechanism disposed coaxially with the input shaft I. That is, the power distribution mechanism P1 includes a carrier ca that supports a plurality of pinion gears, and a sun gear s and a ring gear r that mesh with the pinion gears, respectively, as rotating elements. The sun gear s as the first rotating element is connected to rotate integrally with the rotor Ro1 of the first rotating electrical machine MG1. The carrier ca as the second rotating element is connected to rotate integrally with the input shaft I connected to the output rotating shaft of the engine E. The ring gear r as the third rotating element is connected to rotate integrally with the intermediate shaft M, and the ring gear r is connected to the differential device D via the intermediate shaft M.

  In the configuration shown in FIG. 1, the first rotating electrical machine MG1 is connected to the sun gear s as the first rotating element, and the engine E that is a driving source other than the rotating electrical machines MG1 and MG2 is connected to the carrier ca as the second rotating element. Has been. And the 2nd rotary electric machine MG2 and the ring gear r as a 3rd rotation element are connected to the wheel W through the differential apparatus D (refer FIG. 3). However, the configuration of the drive system is not limited to this configuration. The second rotating electrical machine MG2 may be configured to be directly connected to the differential device D, or connected to the third rotating element or other drive transmission element, and connected to the differential device D via those rotating elements or drive transmission elements. It may be a form.

  FIG. 2 is a block diagram schematically showing a configuration of a rotating electrical machine control system having the rotating electrical machine drive device In as a core. The rotating electrical machine control system includes a battery B, the rotating electrical machines MG1 and MG2, and a rotating electrical machine drive unit In interposed therebetween. The rotating electrical machine drive device In includes a voltage converter (converter) 4 and a frequency converter (inverter) 5 from the battery B side. As shown in FIG. 2, in this embodiment, frequency converters 51 and 52 are individually provided for the pair of rotating electrical machines MG <b> 1 and MG <b> 2 as the frequency converter 5. Between the frequency converter 5 and each of the rotating electrical machines MG1 and MG2, a current sensor 13 for measuring a current flowing through the rotating electrical machine is provided. In this example, a configuration is shown in which the current of all three phases is measured. However, since the three phases are in an equilibrium state and the sum of instantaneous values is zero, the current of only two phases is measured and the remaining in the TCU 10 May be obtained by calculation. The battery B can supply power to the rotating electrical machines MG1 and MG2, and can store electricity by receiving power from the rotating electrical machines MG1 and MG2.

  The voltage conversion unit 4 includes a reactor 4a, a filter capacitor 4b, a pair of upper and lower switching elements 4c and 4d, a discharging resistor 4e, and a smoothing capacitor 4f. As the switching elements 4c and 4d, it is preferable to apply an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET). In the present embodiment, a case where an IGBT is used will be described as an example.

  The source of the upper switching element 4c of the voltage converter 4 is connected to the drain of the lower switching element 4d, and is connected to the positive side of the battery B via the reactor 4a. The drain of the upper switching element 4 c is connected to the input plus side of the frequency converter 5. The source of the lower switching element 4d is connected to the negative side (ground) of the battery B. Since the input minus side of the frequency conversion unit 5 is also ground, the source of the lower switching element 4 d is connected to the input minus side of the frequency conversion unit 5.

  The gates of the upper switching element 4c and the lower switching element 4d are connected to the TCU 10 via the driver circuit 7 (7C). The switching elements 4 c and 4 d are controlled by the TCU 10 to boost the voltage from the battery B and supply it to the frequency conversion unit 5. The TCU 10 controls the switching elements 4c and 4d based on a boost command value set according to the target torque of the rotating electrical machine. Specifically, the TCU 10 turns the upper switching element 4c off and switches the lower switching element 4d on / off by, for example, PWM control to boost and output the voltage of the battery B. On the other hand, when the rotating electrical machine performs a regenerative operation, the voltage conversion unit 4 regenerates the electric power generated by the rotating electrical machine to the battery B. For example, the TCU 10 regenerates power via the voltage conversion unit 4 by turning the lower switching element 4d off and controlling the upper switching element 4c on. Note that when the electric power generated by the rotating electrical machine is stepped down and regenerated in the battery B, the upper switching element 4c may be PWM-controlled.

The frequency conversion unit 5 is configured by a bridge circuit. Two switching elements are connected in series between the input plus side and the input minus side of the frequency converter 5, and this series circuit is connected in parallel in three lines. That is, a bridge circuit in which a set of series circuits corresponds to each of the stator coils U-phase, V-phase, and W-phase of the rotating electrical machines MG1, MG2. In FIG.
Reference numeral 8a is a U-phase upper switching element,
Reference numeral 8b is a V-phase upper switching element.
Reference numeral 8c is a W-phase upper switching element,
Reference numeral 8d is a U-phase lower switching element,
Reference numeral 8e denotes a V-phase lower switching element,
Reference numeral 8f is a W-stage lower switching element. Note that it is preferable to apply IGBTs or MOSFETs to the switching elements 8a to 8f of the frequency converter 5. In this embodiment, the case where IGBT is used is illustrated.

  As shown in FIG. 2, the drains of the upper switching elements 8a, 8b, and 8c of each phase are connected to the output plus side of the voltage converter 4 (the input plus side of the frequency converter 5), and the sources are the lower stages of each phase. The side switching elements 8d, 8e, 8f are connected to the drains. The sources of the lower switching elements 8d, 8e, 8f of each phase are connected to the output minus side of the voltage converter 4 (input minus side of the frequency converter 5), that is, the minus side (ground) of the battery B. ing. The gates of the switching elements 8a to 8f are connected to the TCU 10 via the driver circuit 7 (7A, 7B), and are individually controlled for switching.

  The intermediate points (connection points of the switching elements) 9u, 9v, 9w of the series circuit by the switching elements (8a, 8d), (8b, 8e), (8c, 8f) of each phase are the rotating electrical machines MG1 and MG2. Are connected to the U-phase, V-phase, and W-phase stator windings. The drive current supplied to each winding is detected by the current sensor 13. The detected value by the current sensor 13 is received by the TCU 10 and used for feedback control.

  The rotating electrical machines MG1 and MG2 are provided with rotation detection sensors 11 and 12 such as a resolver that function as a part of the rotation detection unit, and detect the rotation angle (mechanical angle) of the rotor 70r. The rotation detection sensors 11 and 12 are set according to the number of poles (pole pair number) of the rotor 70r, convert the rotation angle of the rotor 70r into an electrical angle θ, and output a signal corresponding to the electrical angle θ. Is possible. The TCU 10 calculates the rotational speed (angular velocity ω) of the rotating electrical machines MG1 and MG2 and the control timing of the switching elements 8a to 8f of the frequency conversion unit 5 based on the rotation angle.

  The TCU 10 supplies the three-phase AC drive current to the rotary electric machines MG1 and MG2 by performing PWM control of the switching elements 8a to 8f based on the target torque and the rotation speed for the rotary electric machines MG1 and MG2. Thereby, each rotary electric machine MG1, MG2 performs powering according to the target rotational speed and the target torque. When the rotating electrical machines MG1 and MG2 function as generators and receive electric power from the rotating electrical machine side, the TCU 10 controls the frequency conversion unit 5 to convert alternating current of a predetermined frequency into direct current.

  In the present embodiment, the vehicle has a two-wheel drive configuration as shown in FIG. The wheels W1 and W2 are drive wheels, and the wheels W3 and W4 are non-drive wheels. As shown in FIG. 3, each wheel W1-W4 is provided with a mechanical friction brake such as a brake 30 (32, 34, 36, 38). These mechanical brakes 30 are operated by hydraulic pressure, gas, electricity or the like. In the case of a vehicle equipped with a hybrid drive system as in this embodiment, it is preferable that braking is electronically controlled so that regenerative braking and friction braking are applied at an appropriate ratio.

  In the present embodiment, the braking system includes an anti-lock brake system (ABS) that suppresses wheel locking during braking of the vehicle to maintain steering and control to an optimal braking distance. ing. Specifically, as shown in FIG. 3, an ABS controller 60 is provided, and the ABS controller 60 detects the initial lock of the wheel W and changes the action of the brake 30 on the wheel.

  When the brake pedal 20 is operated by an occupant, the operating force is transmitted to the master cylinder (MC) 22 and the ABS controller 60 via a brake booster (not shown). Each wheel W is provided with a rotation sensor 40 (42, 44, 46, 48), and the rotational speed and direction of each wheel are detected. The ABS controller 60 determines the necessity of the anti-lock / brake control operation such as the initial lock state of the wheels W based on the detection results of the rotation sensors 40, and executes the anti-lock / brake control. The detection result of the rotation sensor 40 is also transmitted to the TCU 10 via the ABS controller 60 or directly.

  Immediately before the anti-lock / brake control is performed, the vehicle is running and the wheels are rotating. At the time of braking, the rotation of the wheel is rapidly decelerated, so that the drive system, that is, the transformer / axle is moved by the reaction. In the anti-lock / brake control, the wheel 30 is repeatedly locked and released by the brake 30, so that the transformer / axle vibrates. In addition, as described with reference to FIG. 1, the second rotating electrical machine MG2 particularly functions as a motor that assists the driving force for traveling the vehicle, and thus rotates in synchronization with the wheels. Even if the wheel is suddenly decelerated from this state, the rotor Ro2 of the rotating electrical machine MG2 tends to rotate due to the inertial force, causing a twist in the shaft of the drive system, which also causes the transformer and axle to vibrate.

  Therefore, when the anti-lock brake control is executed, active motor damping (AMD) is used to attenuate the vibration of the transformer axle by outputting counter torque in the direction opposite to the vibration direction of the transformer axle to the rotating electrical machine MG2. Control is performed by the TCU 10. In the AMD control, the TCU 10 acquires a detection signal from the rotation sensor 40. This detection signal may be received directly from the rotation sensor 40 by the TCU 10 or may be received via the ABS controller 60. The TCU 10 calculates the wheel speed from the average rotational speed of the left and right wheels W, for example.

  Further, the TCU 10 acquires detection signals from the rotation detection sensors 11 and 12 of the rotating electrical machine, and calculates the rotational speed of the rotating electrical machine. In the AMD control of the present embodiment, counter torque is generated in the second rotating electrical machine MG2, so that the rotational speed of the second rotating electrical machine MG2 is calculated based on the detection result of the rotation detection sensor 12. Here, the wheel speed and the rotational speed of the rotating electrical machine are calculated as a converted speed which is speed information in terms of common shaft so that the two can be directly compared. For example, the conversion speed is calculated in consideration of the rotational speed of the second rotating electrical machine MG2 and the gear ratio of the drive system.

  Next, the TCU 10 obtains the difference between the wheel speed and the converted speed of the rotating electrical machine in terms of the common axis. This difference becomes the basis of the counter torque. The TCU 10 calculates a target torque which is a target value of the counter torque by multiplying the obtained difference by a predetermined torque gain, for example, a torque gain such as 5 Nm / rpm. The difference between the wheel speed and the converted speed of the rotating electrical machine is within a predetermined range such as ± 100 rpm. When a large difference deviates from the range, the maximum value or the minimum value is limited. Further, the target torque is within a predetermined range such as ± 100 Nm. When a large torque that deviates from the range is calculated as a result of the calculation, the torque is limited to the maximum value or the minimum value, respectively. These limitations are for preventing unrealistic counter torque from being calculated as the target torque when the difference is too large.

FIG. 4 is a correlation diagram between the rotation speed of the second rotating electrical machine MG2 and the torque. As described above, the rotating electrical machine drive device In includes the voltage conversion unit 4 and can boost the DC voltage of the battery B. That is, the voltage of the battery B that supplies driving power to the rotating electrical machine is boosted, and the rotational speed at which the field-weakening control is performed is shifted to a higher rotational speed. In the present embodiment, the voltage of the battery B is boosted from the lower side to V4, V3, V2, and V1. FIG. 4 shows the correlation between the rotational speed and the torque and the relationship between the boost command value. In the figure, the line V4 indicates a boundary where the voltage converted by the voltage converter 4 needs to be set to V4. That is, the boundary where V4 is set as the boost command value is shown. Similarly, the lines V3, V2, and V1 indicate boundaries at which the voltages that have been boosted by the voltage converter 4 need to be V3, V2, and V1, respectively. The line T _V1 indicates a torque region that can be output by the second rotating electrical machine MG2 including field-weakening control when the boosted voltage is V1.

In FIG. 4, the line indicated by T _AMD indicates the transition of the target torque during AMD control. In the initial stage of AMD control, the vibration of the transformer axle is large, and a large counter torque is required. Thereafter, the vibration of the transformer axle is gradually attenuated by the effect of the AMD control, and the required value of the counter torque is also reduced. As indicated by the arrow on the T _AMD line, the target torque during AMD control gradually decreases.

  FIG. 5 is a timing chart schematically showing the transition of the boost command value. As apparent from FIGS. 4 and 5 (a), the target torque during AMD control fluctuates greatly in a short time, and therefore frequently exceeds the boundary of the boost command value to the voltage converter 4. The output voltage of the voltage conversion unit 4 follows the circuit including the circuit delay of the voltage conversion unit 4 due to the fluctuation of the boost command value. Since the change in the target torque during the AMD control is high speed, the actual voltage after boosting may be too large or too small relative to the boost command value. If the actual voltage after boosting is excessive, there is a possibility that the allowable voltage Vmax of the rotating electrical machine drive device In is exceeded.

  The allowable voltage Vmax of the rotating electrical machine drive device In is, for example, the breakdown voltage of the switching elements 4c and 4d of the voltage conversion unit 4, particularly the breakdown voltage of the upper switching element 4c, and the switching elements 8a to 8f of the frequency conversion unit 5, particularly the upper stage switching. These are the withstand voltage of the elements 8a to 8c, the withstand voltage of the smoothing capacitor 4f on the output side of the voltage converter 4, and the like. The rotating electrical machine drive device In is normally configured as a wiring board or a unit in which the wiring board is stored, and the maximum voltage defined by the insulation distance in these boards and units is also an allowable voltage.

  In FIG. 5, the boost command value is indicated by a thick solid line, and the fluctuation element of the actual voltage after boosting, which is excessive or excessive, is schematically indicated by a dotted line. As shown in FIG. 5B, when the actual voltage becomes excessive, the allowable voltage Vmax may be exceeded.

  Moreover, since the target torque at the time of AMD control also fluctuates between positive and negative torques, the second rotating electrical machine MG2 frequently repeats power running and regeneration within a short time. In the case of the voltage conversion unit 4 having the configuration shown in FIG. 2, when boosting the voltage of the battery B, the switching element 4c is always controlled to be in an off state, and the switching element 4d is controlled to be switched by, for example, PWM according to the boost command value. Is done. On the other hand, when power is regenerated from the frequency converter 5 side to the battery B, the switching element 4d is always controlled to be in an off state, and the switching element 4c is controlled to be switched as necessary.

  Here, when the switching elements 4c and 4d are simultaneously turned on, the input plus side and the minus side of the frequency converter 5 are short-circuited. Therefore, when the voltage conversion unit 4 switches its operation mode from boosting to regeneration or from regeneration to boosting, a dead time during which the switching elements 4c and 4d are both turned off is provided. During the dead time period, power regeneration to the battery B cannot be performed, and thus the electric power generated by the rotating electrical machine is stored in the smoothing capacitor 4f. At this time, if the generated power is large, the allowable voltage Vmax of the rotating electrical machine drive device In may be exceeded as described above.

  Therefore, in the present invention, as shown in FIG. 5B, the TCU 10 sets the boost command value to a constant AMD boost command value VF regardless of the target torque when executing the AMD control. The AMD boost command value VF is preferably lower than the maximum boost command value. Even when an excessive voltage having the same magnitude as in the conventional case occurs, it is possible to prevent the allowable voltage Vmax of the rotating electrical machine drive device In from being exceeded. Specifically, the boost command value VF at AMD is preferably determined based on the difference between the allowable voltage Vmax of the rotating electrical machine drive device In (voltage converter 4 and frequency converter 5) and the boost command value at AMD. It is. The difference between the allowable voltage of the rotating electrical machine drive device In and the boost command value at AMD is substantially equal to the difference between the allowable voltage Vmax and the output voltage of the voltage converter 4 when the voltage converter 4 appropriately boosts the voltage. . If this difference is larger than the amplitude value of the voltage fluctuation that occurs on the DC side of the frequency converter 5 when the rotary electric machine is AMD-controlled, the voltage on the output side of the voltage converter 4 is the allowable voltage of the rotary electric machine drive device In. Vmax is not exceeded. Accordingly, the AMD boost command value VF is set so that the difference between the allowable voltage Vmax of the rotating electrical machine drive device In and the AMD boost command value VF is larger than the amplitude value of the voltage fluctuation generated on the DC side of the frequency converter 5. Preferably it is set.

Further, the boost command value VF at AMD is set to a value at which the rotating electrical machine can output a predetermined maximum torque at AMD in both positive and negative directions within the entire range within the maximum rotational speed of the rotating electrical machine when AMD control is performed. . Here, the case where the rotating electrical machine is the second rotating electrical machine MG2 will be specifically described with reference to FIG. The “maximum rotational speed of the rotating electrical machine when AMD control is performed” corresponds to “rotational speed S” in FIG. 4. Therefore, “the entire region within the maximum number of rotations” corresponds to the region of the number of rotations S or less in FIG. The “maximum torque during AMD in both positive and negative directions” corresponds to “± T1 torque” in FIG. Therefore, the boost command value corresponding to the generable torque region T _VF torque of ± T1 in rotational speed S becomes the AMD voltage step-up command value VF.

  FIG. 6 is a flowchart showing a procedure for setting the boost command value. The TCU 10 acquires a boost command value VN during normal control (during normal travel) based on the rotational speed of the rotating electrical machine and the target torque (# 1). In this example, one of the multiple steps of boost command values V1 to V4 as shown in FIG. 4 is acquired as the boost command value during normal control. Here, the TCU 10 may execute the calculation using the rotation speed and the target torque as variables to acquire the boost command value VN, or from the table stored in a storage medium such as a memory, the rotation speed. In addition, the boost command value may be read by using the target torque as an argument. Further, the boost command value can be set so as to gradually change with respect to the rotation speed of the rotating electrical machine and the target torque without being made into a plurality of stages.

  Next, the TCU 10 determines whether AMD control is in operation (# 2). When the AMD control is in operation, the boost command value VN during normal control acquired in step # 1 is not used, and the AMD boost command value VF, which is a constant value, is set as the boost command value (# 3 ). On the other hand, if it is determined in step # 2 that the AMD control is not in operation, that is, if the vehicle is traveling normally, the boost command value VN acquired in step # 1 is set as the boost command value (# 4). ).

  In the present embodiment, the first rotating electrical machine MG1 and the second rotating electrical machine MG2 are provided as the rotating electrical machines. Both the first rotating electrical machine MG1 and the second rotating electrical machine MG2 can operate as a motor and a generator, and a boost command value VN during normal control suitable for each operation is set. In the above description, in order to facilitate understanding, an example in which the boost command value VN during normal control is acquired mainly based on the torque and the rotation speed of the second rotating electrical machine MG2 has been shown. However, the boost command value of the second rotating electrical machine MG2 does not always exceed the boost command value of the first rotating electrical machine MG1. Therefore, the TCU 10 receives the boost command value at the time of normal control acquired based on the torque and the rotational speed of the first rotating electrical machine MG1, and the value at the time of normal control acquired based on the torque and the rotational speed of the second rotating electrical machine MG2. It is preferable to obtain the larger one of the boost command values as the boost command value VN during normal control.

[Another embodiment]
(1) In the above-described embodiment described with reference to FIG. 6, the normal control is performed based on the rotation speed and the target torque in step # 1 before determining whether the AMD control is operating in step # 2. The example which acquires the pressure | voltage rise command value VN at the time was shown. However, the TCU 10 may determine whether AMD control is in operation at the beginning of a series of processes. That is, if the AMD control is in operation, the boost command value is set to the AMD boost command value VF, which is a constant value. If not, the boost command value during normal control is set based on the rotation speed and the target torque. The value VN may be acquired and set as a boost command value.

(2) In the above embodiment, an example is shown in which the vehicle is a hybrid vehicle including a rotating electrical machine as a driving source and a driving source (engine) other than the rotating electrical machine. However, the object of the present application is a system including a rotating electrical machine that is driven and controlled by a rotating electrical machine drive device having a voltage conversion unit. Therefore, the drive source may be only a rotating electrical machine, and the present invention can be applied to an electric vehicle using the rotating electrical machine as a drive source.

(3) In the above embodiment, an example has been shown in which a hybrid vehicle is provided with a pair of rotating electrical machines, with one rotating electrical machine serving as a motor and the other rotating electrical machine serving as a generator. However, the present invention can also be applied to any hybrid vehicle that includes a single rotating electric machine and has a mode in which the rotating electric machine functions as a motor and a generator.

  The present invention can be applied to electric vehicles and hybrid vehicles that include a rotating electrical machine as a drive source.

Block diagram schematically showing the configuration of the drive system of the vehicle drive system Block diagram schematically showing the configuration of the rotating electrical machine control system Block diagram schematically showing the configuration of the drive system of the vehicle drive system Correlation diagram of rotating electrical machine speed and torque Timing chart schematically showing the transition of boost command value Flow chart showing the procedure for setting the boost command value

Explanation of symbols

4: Voltage converter 5: Frequency converter 10: TCU (control unit)
B: Battery (DC power supply)
E: Engine In: Rotary electric machine drive device MG1: First rotary electric machine MG2: Second rotary electric machine P1: Power distribution mechanism W: Wheel VN: Normal pressure increase command value VF: AMD pressure increase command value

Claims (7)

DC power supply,
A rotating electric machine for driving the vehicle;
It is interposed between the DC power supply and the rotating electrical machine, converts the output of the DC power supply to alternating current when the rotating electrical machine is powering, and converts the output from the rotating electrical machine to direct current when the rotating electrical machine is regenerated. A frequency converter to convert;
A voltage converter that is interposed between the DC power supply and the frequency converter and boosts the output of the DC power supply based on a boost command value set according to a target torque of the rotating electrical machine;
An active motor that controls the frequency conversion unit and the voltage conversion unit to generate torque in the rotating electrical machine in a direction that suppresses vibration of the drive system of the vehicle that is generated when the antilock brake system of the vehicle is operated. A rotating electrical machine control system including a control unit that performs damping control,
The control unit is a rotating electrical machine control system that sets the boost command value to a constant boost command value during AMD regardless of the target torque when the active motor damping control is executed.   The boost command value during AMD is a predetermined maximum torque during AMD for the active motor damping control by the rotating electrical machine over the entire range within the maximum rotational speed of the rotating electrical machine that performs the active motor damping control. The rotating electrical machine control system according to claim 1, wherein the value is set to a value that can be output in both positive and negative directions.   The step-up command value during AMD is such that the difference between the allowable voltage of the voltage conversion unit and the frequency conversion unit and the step-up command value during AMD is controlled when the rotary electric machine is controlled by the active motor damping. 3. The rotating electrical machine control system according to claim 1, wherein the rotating electrical machine control system is set to be larger than an amplitude value of a voltage fluctuation generated on a direct current side of the motor.   The rotating electrical machine control system according to any one of claims 1 to 3, wherein the AMD boost command value is set to a value lower than a maximum value of the boost command value set according to the target torque.   The control unit generates the rotating electrical machine when the active motor damping control is performed based on the difference between the speed of the wheel and the rotational speed of the rotating electrical machine, which is converted in the common shaft of the drive system of the vehicle. The rotating electrical machine control system according to any one of claims 1 to 4, wherein a torque in a direction to reduce the difference is calculated as the target torque. While comprising the rotating electrical machine control system according to any one of claims 1 to 5,
The rotating electrical machine includes a first rotating electrical machine and a second rotating electrical machine,
A power distribution mechanism that distributes a driving force generated from a driving source other than the first rotating electric machine and the second rotating electric machine, wherein one driving force distributed by the power distributing mechanism is applied to a wheel, and the other driving force; Is transmitted to the first rotating electrical machine, and the driving force generated by the second rotating electrical machine is transmitted to the wheels. The power distribution mechanism is configured to include a planetary gear mechanism having a first rotation element, a second rotation element, and a third rotation element in order of rotational speed,
The first rotating electrical machine is connected to the first rotating element, a drive source other than the rotating electrical machine is connected to the second rotating element, and the second rotating electrical machine and the third rotating element are connected to wheels. The vehicle drive system according to claim 6.

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