JP2009201288A - Rotating electrical machine control system and vehicle drive system equipped with the rotating elecrical machine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electrical machine control system, capable of changing the torque of a rotating electrical machine, at a rate of change of the torque which is required for AMD control in ABS operation. <P>SOLUTION: The rotating electrical machine control system comprises a DC power supply; the rotating electrical machine in order to drive a vehicle; a frequency conversion part that is interposed between the DC power supply and the rotating electric machine; a voltage conversion part that is interposed between the DC power supply and the frequency conversion part and boosts the output of the DC power supply, based on a boosting demand value set according to a target toque of the rotating electric machine; and a control part that controls the rotating electric machine by normal field control or field-weakening control via the frequency conversion part and the voltage conversion part and performs active motor damping control, when an antilock brake system of a vehicle is operated. During execution of the active motor damping control, the control part sets a boosting demand value with a lower-limit boosting demand value VL as a lower-limit value during AMD control that enables the rotating electric machine to generate the target torque by normal field 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. By performing field-weakening control, it is possible to expand the practical rotation range of the electric motor to a higher rotation range.

  As another method, a technique has been proposed in which the voltage of a battery that supplies driving power to an electric motor is boosted to expand the practical rotation range of the electric motor to a higher rotation range (for example, Patent Document 1). ). 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. In patent document 1, the area | region which performs field-weakening control is shifted to the high output side (high rotation speed side) by this method. Thus, the movable region of the electric motor can be expanded by combining the boosting of the battery voltage and the field weakening control.

  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)

  Incidentally, in order to improve the efficiency of the electric motor, motor control using boosting and field weakening control by a converter (boosting circuit) as described in Patent Document 1 and AMD control described in Patent Document 2 are used in combination. There is a case. As described above, the value of the boosted voltage by the converter and the region where field weakening control is performed are set so that the electric motor can be efficiently driven 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. At this time, the target operating point often fluctuates beyond the boundary between field weakening control and normal field control. The field weakening control is control for weakening the field force in order to suppress the counter electromotive force as described above. Therefore, the torque change rate for changing the torque per unit time is lower than that in the normal field control. At the time of AMD control, it is necessary to change the torque at a high torque change rate in order to actively attenuate the intense vibration at the time of ABS operation. However, in the field weakening control, there is a possibility that the torque cannot be changed at the required torque change rate.

  The present invention was devised in view of the above problems, and an object thereof is to provide a rotating electrical machine control system capable of changing the torque of a rotating electrical machine at a torque change rate required for AMD control during ABS operation. And

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;
A frequency converter that is interposed between the DC power source and the rotating electrical machine, and converts the output of the DC power source into AC when at least the rotating electrical machine is powered;
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;
Via the frequency converter and the voltage converter, the rotating electric machine is controlled by normal field control or field weakening control, and vibration of the vehicle drive system that occurs when the antilock brake system of the vehicle is operated is suppressed. A rotating electrical machine control system comprising: a control unit that performs active motor damping control that generates torque in a direction in the rotating electrical machine,
The control unit sets the boost command value by setting the lower limit boost command value at AMD that allows the rotating electrical machine to generate the target torque by the normal field control as a lower limit value when executing the active motor damping control. is there.

  According to this characteristic configuration, when the active motor damping control is executed, the boost command value is set with the AMD lower limit boost command value at which the rotating electrical machine can generate the target torque by the normal field control as the lower limit value. Therefore, the target torque required for active motor damping control is achieved by the normal field control, so that the torque generated by the rotating electrical machine can follow the target torque that changes frequently with a high torque change rate. Become. As a result, appropriate active motor damping control can be implemented.

Moreover, the rotary electric control system according to the present invention includes:
The control unit obtains a normal boost command value during normal driving of the vehicle and an AMD lower limit boost command value, and when executing the active motor damping control, the normal boost command value, It is preferable to set the larger one of the lower limit boost command values for AMD as the boost command value.

  When the normal voltage boost command value is greater than the AMD lower limit voltage boost command value, if the voltage converter performs voltage boost based on the normal voltage boost command value, the torque required for active motor damping control is reliably obtained. It can be generated in a rotating electric machine. Even if the output of the voltage converter includes an extra boost as a result of boosting by the normal boost command value, the period during which the active motor damping control is performed is compared with the time during which the vehicle normally travels. Short enough. Therefore, there is almost no waste of electric power, and it is preferable that the active motor damping control can be reliably performed. Note that the control unit may calculate and acquire the normal boost command value and the AMD lower limit boost command value by calculating by itself, or by reading from a table stored in a memory or the like. Also good.

  The AMD lower limit boost command value of the rotating electrical machine control system according to the present invention is preferably acquired based on the target torque and the rotational speed of the rotating electrical machine.

  The value of the boosted voltage that is the output of the voltage converter is determined according to the rotation speed and torque of the rotating electrical machine, and the boost command value that boosts the output of the DC power supply to the boosted voltage is determined. Therefore, the boost command value for outputting the torque (target torque) necessary for the active motor damping control at a certain rotational speed is determined according to the rotational speed and torque of the rotating electrical machine. When the AMD lower limit boost command value is acquired by the control unit based on the torque and rotation speed required for active motor damping control, the control unit sets the boost command value that can suppress excessive boosting. Can be set. The control unit may calculate and acquire the AMD lower limit boost command value by calculating itself with the rotation speed and the torque as variables, or may calculate the rotation speed and torque from a table stored in a memory or the like. May be obtained by reading as an argument.

  The AMD lower limit boost command value of the rotating electrical machine control system according to the present invention is preferably a constant value regardless of the torque and the rotational speed of the rotating electrical machine.

  According to this configuration, during active motor damping control that requires high-speed processing, the AMD lower limit boost command value is set to a constant value, so that the AMD lower limit boost command value is sequentially acquired according to the torque and the rotational speed. There is no need. As a result, the calculation load of the control unit is reduced, and active motor damping control can be performed more reliably.

  The AMD lower limit boost command value of the rotating electrical machine control system according to the present invention is AMD which is the maximum torque output by the rotating electrical machine by the normal field control when the active motor damping control is performed. It is preferable to set a value lower than the boost command value at which the maximum torque can be output.

  The maximum torque during AMD is not a torque that is always required during active motor damping control. Therefore, it is preferable that the boost command value is set separately for a case where the maximum torque during AMD is required and a case where a torque equal to or less than a predetermined torque smaller than the maximum torque during AMD is required. According to the above configuration, the AMD maximum torque is realized when a boost command value higher than the AMD lower limit boost command value is set. That is, if necessary, a boost command value that is higher than the lower limit boost command value for AMD is set, and energy saving can be realized.

The AMD lower limit boost command value of the rotating electrical machine control system according to the present invention is such that the rotating electrical machine operates in the entire range within the maximum rotational speed of the rotating electrical machine when the active motor damping control is performed. A step-up command capable of outputting a predetermined maximum torque at AMD for the active motor damping control by field control;
The controller may fix the boost command value to the AMD lower limit boost command value when the active motor damping control is executed.

  A boost command that allows the rotating electrical machine to output a predetermined maximum torque at the time of AMD by normal field control over the entire range within the maximum rotational speed of the rotating electrical machine when the active motor damping control is performed. If there is, a voltage command value larger than the AMD lower limit boost command value is not necessary. Therefore, the control unit may fix the boost command value to the AMD lower limit boost command value when executing the active motor damping control. Since the control unit does not need to sequentially acquire the boost command value when executing the active motor damping control, the processing load can be greatly reduced.

  Further, the rotating electrical machine control system according to the present invention is based on the difference between the wheel speed converted by the control unit in the common shaft of the drive system of the vehicle and the rotational speed of the rotating electrical machine. 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 rotating electrical machine control system according to the present invention includes:
The rotating electrical machine includes a first rotating electrical machine and a second rotating electrical machine,
The first rotating electrical machine distributes a driving force generated from a driving source other than the first rotating electrical machine and the second rotating electrical machine, and transmits the other driving force to the wheels. The driving force is transmitted,
In the second rotating electrical machine, the driving force generated by the second rotating electrical machine is transmitted to the wheels,
The normal boost command value is acquired based on a first normal boost command value acquired based on the torque and the rotational speed of the first rotating electrical machine and a torque and rotational speed of the second rotating electrical machine. It is preferable that the larger one of the two normal time boost command values is acquired as the normal boost command value.

  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. Each of the pair of rotating electrical machines operates almost complementarily as a motor and a generator. In particular, when the voltage converter is used in common for a pair of rotating electrical machines, the boost command value can be set with priority given to rotating electrical machines that require a larger boosted voltage.

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. In this embodiment, the voltage of the battery B is boosted to V3 and V1 from the lower side. FIG. 4 shows the correlation between the rotational speed and the torque and the relationship between the boost command value. In the drawing, a line V3 indicates a boundary where the voltage converted by the voltage converter 4 needs to be V3. That is, the boundary where V3 is set as the boost command value is shown. In the present embodiment, the region on the left side of the V3 line indicates a case where the output of the voltage conversion unit 4 is V5 lower than V3 (for example, equivalent to the voltage of the battery B). Similarly, the line V1 indicates a boundary where the voltage converted by the voltage converter 4 needs to be set to V1. 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 diagram showing the relationship between the boost command value and the control method in the correlation diagram between the rotational speed and torque of the rotating electrical machine. When the boost command value is V5 (without boost), the rotating electrical machine is controlled by the normal field control when the rotational speed of the rotating electrical machine is lower than the line S5, and weak when the rotational speed is high around the line S5. The rotating electrical machine is controlled by field control. Similarly, when the boost command value is V3, the rotating electrical machine is controlled by the normal field control when the rotational speed of the rotating electrical machine is lower than the line S3, and is rotated by the field weakening control when the rotational speed is high at the line S3. The electric machine is controlled. Similarly, when the boost command value is V1, the rotating electrical machine is controlled by the normal field control when the rotational speed of the rotating electrical machine is lower than that of the line S1, and is rotated by the field weakening control when the rotational speed is high around the line S1. The electric machine is controlled.

  FIG. 6 is a timing chart schematically showing the transition of the boost command value. As apparent from FIGS. 4, 5, and 6 (a), the target torque at the time of AMD control is largely switched in a short time and frequently exceeds the boundary of the boost command value to the voltage conversion unit 4. The boost command value is also frequently switched. Further, as shown in FIG. 5, not only the boundary of the boost command value is exceeded, but the boundary between the normal field control and the weak field control is frequently exceeded. In the case of AMD control, for example, it is necessary to control the torque of the rotating electrical machine at a torque change rate of about 6000 Nm / s. However, in the field-weakening control in which the torque change rate is low compared to the normal field control, such a torque change rate is Cannot be achieved.

  Therefore, as shown in FIG. 6B, when executing the AMD control, the TCU 10 sets the boost command value with the lower limit boost command value VL during AMD at which the rotating electrical machine can generate the target torque by the normal field control as the lower limit value. . Specifically, the TCU 10 acquires the normal boost command value VN (VN: V1, V3, V5) and the AMD lower limit boost command value VL during normal driving of the vehicle (during normal control of the rotating electrical machine). When executing the AMD control, the larger one of the normal boost command value VN and the AMD lower limit boost command value VL is set as the boost command value. In FIG. 6B, the normal boost command value VN indicated by the wavy line is lower than the AMD lower limit boost command value VL, and thus is not set as the boost command value. In the example shown in FIG. 6B, the AMD lower limit boost command value VL is a constant value regardless of the torque and the rotational speed of the rotating electrical machine.

  FIG. 7 is a flowchart showing a procedure for setting the boost command value. First, the TCU 10 acquires the boost command value VN during normal control, that is, the normal boost command value VN based on the rotation speed of the rotating electrical machine and the target torque (# 1). In this example, one of a plurality of boost command values V1, V3, and V5 as shown in FIG. 4 is acquired as the normal boost command value VN. 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. Alternatively, 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). If it is determined that the AMD control is not in operation, that is, if the rotating electrical machine is in normal control, the normal time boost command value VN acquired in step # 1 is set as the boost command value (# 6).

  On the other hand, if it is determined in step # 2 that the AMD control is in operation, the magnitudes of the normal time boost command value VN acquired in step # 1 and the predetermined AMD lower limit boost command value VL are Compared (# 3). If it is determined that the normal boost command value VN acquired in step # 1 exceeds the AMD lower limit boost command value VL, the normal boost command value VN acquired in step # 1 is set as the boost command value. (# 5). On the other hand, if the normal boost command value VN acquired in step # 1 is equal to or lower than the AMD lower limit boost command value VL, the AMD lower limit boost command value VL is set as the boost command value (# 4).

  The lower limit boost command value VL at AMD is set to a value lower than the boost command value at which the maximum torque at AMD, which is the maximum torque output by the rotating electrical machine by normal field control when AMD control is performed, can be output. Is preferred. In the example shown in FIGS. 4 to 6, the boost command value that can output the maximum torque during AMD, which is the maximum torque output by the rotating electrical machine by the normal field control, is V1. Therefore, when the maximum torque at AMD is required, the boost command value is set to the maximum value V1, and the torque achievable at a voltage lower than V1 is set to a value lower than the maximum value V1. When the command value VL is used, AMD control can be executed efficiently.

  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 normal time boost command value VN suitable for each operation is set. In the above description, in order to facilitate understanding, an example in which the normal time boost command value VN is obtained mainly based on the torque and the rotational 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. Accordingly, the first normal time boost command value acquired by the TCU 10 based on the torque and the rotational speed of the first rotating electrical machine MG1 and the second normal time acquired based on the torque and the rotational speed of the second rotating electrical machine MG2. It is preferable to acquire the larger one of the boost command values as the normal boost command value VN.

[Another embodiment]
(1) In the above-described procedure described with reference to FIG. 7, the AMD lower limit boost command value VL is set to a constant value regardless of the torque and the rotational speed of the rotating electrical machine. However, the present invention is not limited to this, and the AMD lower limit boost command value VL may be obtained each time based on the target torque and the rotational speed of the rotating electrical machine, and may vary. Specifically, based on the target torque and the rotation speed, a value capable of generating the target torque by the normal field control is acquired as the AMD lower limit boost command value VL. The normal boost command value VN is acquired in the same manner, but the normal boost command value VN may be a boost voltage command value that can generate the target torque by field weakening control. However, the AMD lower limit boost command value VL as the fluctuation value is acquired as a value capable of generating the target torque by the normal field control. Therefore, even if the values are acquired based on the same target torque and rotation speed, different values are acquired, and for example, an appropriate value is selected as the boost command value in step # 3 shown in FIG.

  In this way, when the AMD lower limit boost command value VL becomes a fluctuation value, a step is added before Step # 3 of the flowchart shown in FIG. 7, and the AMD lower limit boost command value VL is set to the torque and rotation of the rotating electrical machine. It may be acquired based on the number. Note that the TCU 10 itself may perform calculation using the rotation speed and the target torque as variables to obtain the AMD lower limit boost command value VL, or from a table stored in a storage medium such as a memory, The AMD lower limit boost command value VL may be read and acquired using the rotation speed and the target torque as arguments.

(2) When the normal time boost command value VN is read from a table stored in a storage medium such as a memory using the rotation speed and the target torque as arguments, the boost command value at the time of AMD control is also the same. It may be configured to be stored in a storage medium such as a memory and to be read out using the rotation speed and target torque during AMD control as arguments. In this case, it is preferable that the boost command value at the time of AMD control is stored not as a lower limit value but as a final determined value. In other words, a table from which, for example, V1 or VL is read as a boost command value corresponding to the rotation speed and target torque at the time of execution of AMD control may be stored in a storage medium such as a memory. In this case, the TCU 10 is configured to be able to refer to the two tables in which the boost command values are stored. Similar to step # 2 in FIG. 7, the TCU 10 determines whether or not “AMD control is in operation”, and the determination result. Depending on the table, the table to be referred to may be different. That is, the boost command value at the time of AMD control can be set without executing the step of comparing the normal boost command value VN and the AMD lower limit boost command value VL as in step 3 shown in FIG. .

(3) The lower limit boost command value at AMD is a boost command that allows the rotating electrical machine to output a predetermined maximum torque at AMD by normal field control over the entire range within the maximum rotational speed of the rotating electrical machine when AMD control is performed. It may be set as a value (AMD boost command value VF). In this case, a boost command value exceeding the lower limit boost command value at AMD (AM boost command value VF), for example, a boost command value V1 shown in FIG. 8 is not necessary. Therefore, from the viewpoint of energy efficiency, the TCU 10 may fix the boost command value to the AMD boost command value VF when executing the AMD control. In this case, as shown in FIG. 9, the procedure for setting the boost command value is simpler than the procedure shown in FIG. First, the TCU 10 acquires the normal time boost command value VN (# 10) and determines whether the AMD control is in operation (# 20), which is the same as in the above embodiment. Similarly, when it is determined that the AMD control is not in operation, the normal boost command value VN acquired in step # 10 is set as the boost command value (# 60). On the other hand, if it is determined that the AMD control is in operation, the magnitude of the normal boost command value VN acquired in step # 10 and the predetermined AMD boost command value VF are not compared. The boost command value VF at AMD is set as the boost command value (# 40).

Here, the fact that the rotating electrical machine can output a predetermined maximum torque during AMD in both positive and negative directions in the entire region within the maximum rotational speed of the rotating electrical machine when AMD control is performed will be specifically described with reference to FIG. Explained. “The maximum number of rotations of the rotating electrical machine when AMD control is performed” corresponds to “the number of rotations S” in FIG. 5. Therefore, “the entire region within the maximum number of revolutions” corresponds to the region of the number of revolutions 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 torque region S _{VF in} which the torque of ± T1 can be generated at the rotation speed S is the AMD boost command value VF. As shown in FIG. 5, the lower limit boost command value VL at AMD is not capable of outputting the maximum torque ± T1 at AMD by the rotating electrical machine in the region below the rotational speed S of the rotating electrical machine (see the _SVL region). In addition, V1, which is one of the normal time boost command values, can output the maximum torque ± T1 during AMD in the region where the rotational speed is S or more (see the S1 region). Therefore, the AMD boost command value VF is set to a value larger than the AMD lower limit boost command value VL and smaller than V1, which is one of the normal boost command values.

(4) In the above-described embodiment, an example in which the vehicle is a hybrid vehicle including a rotating electric machine as a driving source and a driving source (engine) other than the rotating electric machine has been described. 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 rotary electric machine, and the present invention can be applied to an electric vehicle using a so-called rotary electric machine as a drive source as a vehicle.

(5) In the above embodiment, an example has been described in which the hybrid vehicle includes a pair of rotating electric machines, one rotating electric machine serving as a motor, and the other rotating electric machine serving as a generator. However, the present invention can be applied to any hybrid vehicle including a single rotating electric machine and 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 A diagram showing the relationship between the boost command value and the control method in the correlation diagram between the rotational speed and torque of the rotating electrical machine Timing chart schematically showing the transition of boost command value Flow chart showing the procedure for setting the boost command value Timing chart schematically showing a transition of a boost command value according to another embodiment The flowchart which shows the procedure which sets the pressure | voltage rise command value which concerns on another embodiment

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 boost command value VL: AMD lower limit boost command value VF: AMD boost command value

Claims (10)

DC power supply,
A rotating electric machine for driving the vehicle;
A frequency converter that is interposed between the DC power source and the rotating electrical machine, and converts the output of the DC power source into AC when at least the rotating electrical machine is powered;
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;
Via the frequency converter and the voltage converter, the rotating electric machine is controlled by normal field control or field weakening control, and vibration of the vehicle drive system that occurs when the antilock brake system of the vehicle is operated is suppressed. A rotating electrical machine control system comprising: a control unit that performs active motor damping control that generates torque in a direction in the rotating electrical machine,
The controller is configured to set the boost command value with the lower limit boost command value during AMD at which the rotary electrical machine can generate the target torque by the normal field control when the active motor damping control is executed. Control system.   The control unit obtains a normal boost command value during normal driving of the vehicle and an AMD lower limit boost command value, and when executing the active motor damping control, the normal boost command value, 2. The rotating electrical machine control system according to claim 1, wherein a larger one of AMD lower limit boost command values is set as the boost command value.   The rotating electrical machine control system according to claim 1, wherein the AMD lower limit boost command value is acquired based on a target torque and a rotational speed of the rotating electrical machine.   3. The rotating electrical machine control system according to claim 1, wherein the AMD lower limit boost command value is a constant value regardless of the torque and the rotational speed of the rotating electrical machine.   The lower limit boost command value at AMD is the boost command value at which the maximum torque at AMD, which is the maximum torque output from the rotating electrical machine by the normal field control when the active motor damping control is performed, can be output. The rotating electrical machine control system according to any one of claims 1 to 4, which is set to a lower value. The AMD lower limit boost command value is a predetermined value for the active motor damping control by the rotating electrical machine by the normal field control in the entire range within the maximum rotational speed of the rotating electrical machine that performs the active motor damping control. Is a boost command that can output the maximum torque during AMD,
The rotating electrical machine control system according to claim 1, wherein the control unit fixes the boost command value to the AMD lower limit boost command value when the active motor damping control is executed.   The control unit generates the rotating electrical machine when the active motor damping control is performed based on a difference between a wheel speed converted in a common shaft of the drive system of the vehicle and a rotational speed of the rotating electrical machine. The rotating electrical machine control system according to any one of claims 1 to 6, wherein a torque in a direction to reduce the difference is calculated as the target torque. The rotating electrical machine includes a first rotating electrical machine and a second rotating electrical machine,
The first rotating electrical machine distributes a driving force generated from a driving source other than the first rotating electrical machine and the second rotating electrical machine, and transmits the other driving force to the wheels. The driving force is transmitted,
In the second rotating electrical machine, the driving force generated by the second rotating electrical machine is transmitted to the wheels,
The control unit includes a first normal time boost command value acquired based on the torque and the rotational speed of the first rotating electrical machine, and a second normal time acquired based on the torque and the rotational speed of the second rotating electrical machine. The rotating electrical machine control system according to claim 2, wherein a larger one of the boost command values is acquired as the normal boost command value. While comprising the rotating electrical machine control system according to any one of claims 1 to 8,
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 9.

Images