JP2012051532A - Hybrid vehicle control device - Google Patents

Abstract

A control device for a hybrid vehicle capable of switching a rotating magnetic field control and a fixed magnetic field control at an appropriate timing and locking a rotating electric machine without generating a shock or the like.
A control device for a hybrid vehicle is mounted on a vehicle and includes an internal combustion engine, a rotating electrical machine, a differential mechanism, a lock unit, and a control unit. The locking means locks the rotating electrical machine. The control means controls the rotating electric machine from rotating magnetic field control to fixed magnetic field control when the rotating electric machine is locked to the locking means and the rotating electric machine is controlled so that the rotational speed of the rotating electric machine becomes substantially zero. Switch.
[Selection] Figure 8

Description

  The present invention relates to a control device suitable for a hybrid vehicle.

  Conventionally, in addition to an internal combustion engine (engine), a hybrid vehicle including a rotating electric machine (motor generator) that functions as an electric motor or a generator is known. For example, Patent Document 1 discloses a configuration in which the vehicle can be switched between a non-generator mode in which the generator is fixed (locked) by a brake and a power generation mode in which the brake is released, and the brake is applied after the generator rotational speed approaches zero. A hybrid vehicle is disclosed that is capable of reducing shock during engagement by engaging. Patent Document 2 discloses that the motor is switched from rotating magnetic field control to fixed magnetic field control when the vehicle is stopped. Furthermore, Patent Document 3 discloses that a larger current is supplied to the motor as the rotation limiting torque of the motor is larger, thereby forming a fixed magnetic field of the stator.

JP 09-156387 A JP2008-259328 JP2008-143467

  In a hybrid vehicle having first and second motor generators and locking the first motor generator according to the travel mode, the motor generator is locked by bringing the rotation speed of the first motor generator close to 0 Therefore, it is necessary to accurately grasp the reaction torque of the engine. However, the reaction torque may not be accurately grasped due to disturbance or the like. In this case, it takes time to converge the rotation speed of the first motor generator to zero. As another example, even when the fixed motor control is executed during the change in the rotation speed to lock the first motor generator, the torque applied to the first motor generator during the change is grasped. Since this is not possible, the driving force cannot be compensated for by the second motor generator, and a shock may occur.

  The present invention has been made to solve the above-described problems, and is a hybrid vehicle that can switch between rotating magnetic field control and fixed magnetic field control at an appropriate timing and can lock the rotating electric machine without generating a shock or the like. An object of the present invention is to provide a control device.

  In one aspect of the present invention, an internal combustion engine, a rotating electrical machine capable of rotating the rotor by a rotating magnetic field of a stator and transmitting power to a rotating shaft, a first rotating element coupled to the internal combustion engine, A differential mechanism having a plurality of rotational elements capable of differentially rotating with each other, including a second rotating element coupled to the rotating electrical machine and a third rotating element coupled to a drive shaft; and rotation of the rotating electrical machine. A locking means for locking, and when the rotational speed of the rotating electrical machine becomes substantially 0 by controlling the rotating electrical machine when the locking means is locked to the rotating electrical machine, From the rotating magnetic field control that controls the rotating electric machine so that the rotor is rotationally driven by the rotating magnetic field of the stator, the rotating electric machine is configured such that the rotation of the rotor is restricted by fixing the direction of the magnetic field of the stator. To control the fixed magnetic field And a control means for switching control to a.

  The control apparatus for a hybrid vehicle is mounted on a vehicle and includes an internal combustion engine, a rotating electrical machine, a differential mechanism, a lock unit, and a control unit. The lock means is, for example, an electromagnetic dog clutch mechanism, a cam lock mechanism, or a brake mechanism, and locks the rotating electrical machine. The control means is, for example, an ECU (Electronic Control Unit), and controls the rotating electrical machine when the rotational speed of the rotating electrical machine becomes substantially zero by controlling the rotating electrical machine when the rotating electrical machine is locked by the locking means. Switch from rotating magnetic field control to fixed magnetic field control. Here, “the rotational speed of the rotating electrical machine is approximately 0” is 0 or a value corresponding to 0, and is determined in advance based on experiments or the like in a range where the same effect as in the case of 0 is obtained. By doing in this way, the control apparatus of a hybrid vehicle can make the rotation speed of a rotary electric machine zero even if it does not grasp | ascertain an engine reaction force correctly. Moreover, the control apparatus of a hybrid vehicle can prevent the rotation speed of a rotary electric machine from hunting after switching to fixed magnetic field control, and can suppress the shock based on the fluctuation | variation of an inertia torque.

  In one aspect of the control apparatus for a hybrid vehicle, when the locking unit locks the rotating electrical machine by the locking unit, the control unit sets a target value for the rotational speed of the rotating electrical machine to a value that crosses 0 from the rotational speed of the rotating electrical machine. Set to. In other words, the control means sets the target rotational speed of the rotating electrical machine to a positive value when the rotational speed of the rotating electrical machine is negative, and sets the target rotational speed of the rotating electrical machine when the rotational speed of the rotating electrical machine is positive. Is set to a negative value, so that the rotational speed of the rotating electrical machine is reduced to zero. By doing in this way, the control apparatus of a hybrid vehicle can suppress that the timing of switching to fixed magnetic field control is delayed.

  In another aspect of the control apparatus for a hybrid vehicle described above, the hybrid vehicle further includes power storage means capable of supplying electric power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine, wherein the control means is When the rotating electrical machine is locked and the allowable discharge power of the power storage means is a predetermined value or less, the control of the rotating electrical machine is not switched to the fixed magnetic field control, and the rotation of the rotating electrical machine is stopped by the rotating magnetic field control. Let The “predetermined value” may be a dynamically determined variation value or a predetermined fixed value. In addition, the “discharge allowable power of the power storage means” is the upper limit value of the power that can be output from the power storage means. By doing in this way, the control apparatus of a hybrid vehicle can prevent that it becomes impossible to generate a fixed magnetic field when switching from rotating magnetic field control to fixed magnetic field control.

  In another aspect of the control apparatus for a hybrid vehicle described above, the hybrid vehicle further includes power storage means capable of supplying electric power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine, wherein the control means is When the rotating electrical machine is locked and the state quantity corresponding to the storage state of the power storage means is equal to or less than a predetermined value, the rotation of the rotating electrical machine is stopped by the rotating magnetic field control without switching to the fixed magnetic field control. The “predetermined value” may be a dynamically determined variation value or a predetermined fixed value. By doing in this way, the control apparatus of a hybrid vehicle can prevent that it becomes impossible to generate a fixed magnetic field when switching from rotating magnetic field control to fixed magnetic field control.

  In another aspect of the control apparatus for a hybrid vehicle described above, the hybrid vehicle further includes power storage means capable of supplying electric power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine, wherein the control means is When the rotating electrical machine is locked and the limit value of the current flowing through the rotating electrical machine is equal to or less than a predetermined value, the rotation of the rotating electrical machine is stopped by the rotating magnetic field control without switching to the fixed magnetic field control. The “predetermined value” may be a dynamically determined variation value or a predetermined fixed value. By doing in this way, the control apparatus of a hybrid vehicle can prevent that it becomes impossible to generate a fixed magnetic field when switching from rotating magnetic field control to fixed magnetic field control.

  In another aspect of the control apparatus for a hybrid vehicle, the control means may control the torque applied to the rotating shaft before switching the magnetic field strength of the stator in the fixed magnetic field control to the fixed magnetic field control. Set weaker as the fluctuation range is smaller. By doing in this way, the control apparatus of a hybrid vehicle can set appropriately the magnetic field intensity of a rotary electric machine.

An example of the schematic block diagram of the hybrid vehicle which concerns on each embodiment of this invention is shown. It is an example of the schematic block diagram of a hybrid drive device. (A) Operation | movement alignment chart in the case of continuously variable transmission mode is shown. (B) An operation alignment chart in the case of the fixed gear ratio mode is shown. An example of the time chart of MG1 rotation speed and MG1 torque in 1st Embodiment is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in the time of the period tw1, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in the time t2, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in time t3, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. It is an example of the flowchart which shows the process sequence of 1st Embodiment. An example of the time chart in a 1st comparative example is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in the time of the period tw2, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in a certain time of period tw3, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in a certain time of period tw4, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. An example of the time chart in a 2nd comparative example is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in the time t3 of a 2nd comparative example, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) It is the figure which showed the positional relationship of the stator magnetic pole and rotor magnet in a certain time of period tw12, and the direction of various torques. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to a rotor magnet phase is shown. (A) The graph of the time change of MG1 rotation speed when MG1 rotation speed is negative at the time of lock transition control, and target rotation speed is set to "0" is shown. (B) A graph of the time change of the MG1 rotational speed when the MG1 rotational speed is a negative value during lock transition control and the target rotational speed is set to a predetermined positive value. It is an example of the flowchart which shows the process sequence of 2nd Embodiment. (A) The graph of the torque which generate | occur | produces in motor MG1 corresponding to each rotor magnet phase in a fixed magnetic field is shown. (B) The graph of the torque which generate | occur | produces in motor MG1 corresponding to each rotor magnet phase in a fixed magnetic field in case a torque fluctuation range is small is shown. It is a table which shows the relationship between the intensity of the fixed magnetic field after control switching, and a torque fluctuation range. (A) It is an example of the correction table at the time of high rotation change. (B) It is an example of the low rotation change correction table. It is an example of the flowchart which shows the process sequence of 3rd Embodiment. It is an example of the flowchart which shows the procedure of the acquisition process of the torque fluctuation width of 3rd Embodiment. It is an example of the flowchart which shows the process sequence of 4th Embodiment. It is an example of the flowchart which shows the procedure of a control switching feasibility determination process. It is an example of the flowchart which shows the process sequence concerning the other example of control switching feasibility determination processing.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Constitution]
First, an example of the configuration of a hybrid vehicle 1 to which the hybrid vehicle control device according to the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a hybrid vehicle 1. The hybrid vehicle 1 includes an ECU 100, a PCU (Power Control Unit) 11, a battery 12, an accelerator opening sensor 13, a vehicle speed sensor 14, and a hybrid drive device 10.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an A / D (Analog to Digital) converter, an input / output interface, and the like. It is an electronic control unit for controlling. The ECU 100 executes control described later according to a control program stored in the ROM. The ECU 100 functions as a “control unit” in the present invention. The physical, mechanical, and electrical configurations of the respective means according to the present invention are not limited to this, and for example, each means includes various computers such as a plurality of ECUs, various processing units, various controllers, or a microcomputer device. It may be a system or the like.

  The hybrid drive device 10 drives the hybrid vehicle 1 by supplying driving torque as driving force to the left axle SFL (corresponding to the left front wheel FL) and the right axle SFR (corresponding to the right front wheel FR), which are the axles of the hybrid vehicle 1. Drive unit. The detailed configuration of the hybrid drive device 10 will be described later.

  The PCU 11 includes an inverter (not shown), and is a control unit that controls power input / output between the battery 12 and each motor generator described later, or power input / output between the motor generators not via the battery 12. is there. Specifically, the PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to each motor generator, and converts the AC power generated by each motor generator into DC power and supplies it to the battery 12. To do. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 is a battery unit that has a configuration in which a plurality of unit battery cells are connected in series and functions as a power supply source related to power for powering each motor generator. The battery 12 is an example of the “storage unit” in the present invention.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening “Ta” as an operation amount of an accelerator pedal (not shown) of the hybrid vehicle 1. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period.

  The vehicle speed sensor 14 is a sensor that detects the vehicle speed “V” of the hybrid vehicle 1. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

  Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the hybrid drive device 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof is omitted as appropriate.

  In FIG. 2, the hybrid drive device 10 is abbreviated as an engine 200, a power split mechanism 300, a motor generator MG1 (hereinafter abbreviated as “motor MG1” as appropriate), and a motor generator MG2 (hereinafter abbreviated as “motor MG2” as appropriate). ), An input shaft 400, a lock mechanism 500, an MG2 reduction mechanism 600, and a speed reduction mechanism 700.

  The engine 200 is an inline four-cylinder gasoline engine that functions as a main power source of the hybrid vehicle 1. The engine 200 is an example of the “internal combustion engine” in the present invention. The engine 200 is a known gasoline engine, and a detailed configuration thereof is omitted here. However, the engine torque “Te” as the output power of the engine 200 is input to the hybrid drive device 10 via a crankshaft (not shown). The shaft 400 is connected. Here, “connected” includes a structure that directly transmits power (rotation), and also includes a structure that indirectly transmits power via one or more members.

  The motor MG1 is a motor generator having a power running function that converts electrical energy into kinetic energy and a regenerative function that converts kinetic energy into electrical energy. The motor MG1 is an example of the “rotary electric machine” in the present invention.

  The motor MG2 is a motor generator having a larger physique than the motor MG1, and includes a power running function that converts electrical energy into kinetic energy and a regenerative function that converts kinetic energy into electrical energy, similar to the motor MG1.

  Motor MG1 and motor MG2 function as a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. Hereinafter, the rotor of the motor MG1 is referred to as “rotor RO”, and the stator of the motor MG1 is referred to as “stator ST”. The rotor RO is an example of the “rotor” of the present invention, and the stator ST is an example of the “stator” of the present invention.

  Power split device 300 is a planetary gear mechanism, and is arranged between sun gear S1 provided at the center, ring gear R1 provided concentrically on the outer periphery of sun gear S1, and between sun gear S1 and ring gear R1. A plurality of pinion gears (not shown) that revolve while rotating on the outer periphery of S1, and a carrier C1 that supports the rotation shaft of each pinion gear. The power split mechanism 300 is an example of the “differential mechanism” in the present invention.

  Here, the sun gear S1 is coupled to the rotor RO of the motor MG1 so as to share the rotation axis thereof, and the rotation speed is referred to as the rotation speed of the motor MG1 (hereinafter referred to as “MG1 rotation speed Nmg1”). Is equivalent. The sun gear S1 is an example of the “second rotating element” in the present invention. The ring gear R1 is connected to a ring gear R2 (described later) of the speed reduction mechanism 700 and the MG2 reduction mechanism 600, and the rotation speed thereof is the rotation speed of the drive shaft OUT (hereinafter referred to as “output rotation speed Nout”). Is equivalent. The ring gear R1 is an example of the “third rotating element” in the present invention. Further, the carrier C1 is connected to an input shaft 400 that is connected to the crankshaft of the engine 200, and the rotational speed thereof is equivalent to the rotational speed of the engine 200 (hereinafter referred to as “engine rotational speed Ne”). is there. The carrier C1 is an example of the “first rotating element” in the present invention.

  The MG2 reduction mechanism 600 is a planetary gear mechanism similar to the power split mechanism 300. MG2 reduction mechanism 600 is disposed between sun gear S2 provided at the center, ring gear R2 provided concentrically on the outer periphery of sun gear S2, and between sun gear S2 and ring gear R2, and rotates on the outer periphery of sun gear S2. A plurality of pinion gears (not shown) that revolve while revolving, and a carrier C2 that supports the rotation shaft of each pinion gear. Further, the rotor of motor MG2 is coupled to sun gear S2.

  Here, the ring gear R2 of the MG2 reduction mechanism 600 is connected to the ring gear R1 of the power split mechanism 300 as described above, and exhibits an unambiguous rotational state with respect to the axle. The carrier C2 is fixed so as not to rotate by a fixing element. Therefore, the motor MG2 fixed to the sun gear S2 which is the remaining one rotation element has a form in which the rotation of the drive shaft OUT is decelerated according to the reduction ratio determined according to the gear ratio of each gear constituting the MG2 reduction mechanism 600. Communicated in Thus, MG2 reduction mechanism 600 functions as a reduction gear mechanism. The composite planetary gear mechanism defined by the MG2 reduction mechanism 600 and the power split mechanism 300 is a differential mechanism with two degrees of rotation. Therefore, the rotational speed of motor MG2 (hereinafter referred to as “MG2 rotational speed Nmg2”) is uniquely determined according to vehicle speed V.

  The speed reduction mechanism 700 is a gear mechanism that includes a drive shaft OUT that exhibits a rotational state that is unambiguous with the axle, a reduction gear (reference number omitted) connected to the drive shaft OUT, and a differential (reference number omitted). The rotational speed of each axle is transmitted to the drive shaft OUT while being decelerated by the reduction mechanism 700 according to a predetermined gear ratio. As described above, the ring gear R1 and the ring gear R2 are connected to the drive shaft OUT, and each ring gear has a structure that uniquely rotates with the vehicle speed V.

  Unlike motor MG1 and engine 200, motor MG2 can apply an output torque (hereinafter referred to as “MG2 torque Tmg2”) to drive shaft OUT. Therefore, the motor MG2 can assist the traveling of the hybrid vehicle 1 by applying torque to the drive shaft OUT, and can also perform power regeneration by inputting torque from the drive shaft OUT. The MG2 torque Tmg2 is controlled by the ECU 100 via the PCU 11 together with the input / output torque of the motor MG1 (hereinafter referred to as “MG1 torque Tmg1”).

  The hybrid drive device 10 is provided with a rotation sensor such as a resolver in a portion corresponding to the illustrated broken line frames A1 and A2. These rotation sensors are in a state of being electrically connected to the ECU 100, and the detected rotation speed (rotational angular velocity) is sent to the ECU 100 at a constant or indefinite period. Supplementally, the rotational speed of the part corresponding to the illustrated broken line frame A1 is MG2 rotational speed Nmg2, and the rotational speed of the part corresponding to the illustrated broken line frame A2 is MG1 rotational speed Nmg1.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the input shaft 400 under the above-described configuration is applied to the sun gear S1 and the ring gear R1 by the carrier C1 at a predetermined ratio, specifically, between the gears. Distribute at a ratio according to the gear ratio. In other words, the power split mechanism 300 can split the power of the engine 200 into two systems. At this time, when the gear ratio “P” as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, when the engine torque Te is applied to the carrier C1 from the engine 200, the torque “Tes” applied to the sun gear S1. "Is expressed by the following equation (1), and torque appearing on the drive shaft OUT (hereinafter referred to as" engine direct torque Tor ") is expressed by the following equation (2).

Tes = −Te × P / (1 + P) (1)
Ter = Te × 1 / (1 + P) (2)
The lock mechanism 500 is an engagement device configured to be able to selectively switch the state of the sun gear S1 between a non-rotatable locked state and a rotatable released state, and is an example of the “locking unit” in the present invention. It is. Here, the sun gear S1 is connected to the motor MG1 as described above, and when the sun gear S1 is in a locked state, the motor MG1 is also in a locked state where it cannot rotate. Hereinafter, the fact that the sun gear S1 is in the locked state is appropriately expressed as “the motor MG1 is in the locked state”. The locking mechanism 500 may be, for example, a meshing engagement device such as an electromagnetic dog clutch that engages the engagement elements by meshing the tooth-like members formed on each of the pair of engagement elements. However, a so-called electromagnetic cam lock type engagement device may be used. In another example, the lock mechanism 500 includes a plurality of engagement elements configured to be able to engage and disengage with each other according to a control hydraulic pressure supplied by a hydraulic control mechanism (not shown). It may be.

[Control method]
Below, the control method which ECU100 performs is demonstrated concretely.

(Basic control in each speed change mode)
The hybrid vehicle 1 can select the fixed gear ratio mode and the continuously variable transmission mode according to the state of the sun gear S1 of the power split mechanism 300 to be locked. Hereinafter, basic control in each shift mode will be described.

  FIGS. 3A and 3B are operation collinear diagrams illustrating one operation state of the hybrid drive device 10. Specifically, FIG. 3A shows an operation alignment chart in the case of the continuously variable transmission mode. FIG. 3B shows an operation alignment chart in the case of the fixed gear ratio mode. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof is omitted as appropriate.

  In FIG. 3A, the vertical axis represents the rotational speed, and the horizontal axis represents the motor MG1 (uniquely the sun gear S1), the engine 200 (uniquely the carrier C1), and the motor MG2 (uniquely) in order from the left. Drive axis OUT).

  Here, the power split mechanism 300 is a planetary gear mechanism having a plurality of rotational elements having a differential relationship with each other, and has two rotational degrees of freedom, and the rotational speed of two elements of the sun gear S1, the carrier C1, and the ring gear R1 is When determined, the number of rotations of the remaining one rotation element is inevitably determined. That is, on the operation collinear diagram, the operation state of each rotating element is represented by one operation collinear line corresponding to one operation state of the hybrid drive device 10 on a one-to-one basis.

  In FIG. 3A, it is assumed that the operating point of the motor MG2 that is uniquely related to the vehicle speed V and the output rotational speed Nout is the operating point “m1”. In this case, if the operating point of the motor MG1 is the operating point “g1”, the operating point of the engine 200 connected to the carrier C1 which is the remaining rotating element is the operating point “e1”. At this time, if the ECU 100 changes the operating point of the motor MG1 to the operating point “g2” and the operating point “g3” while maintaining the output rotation speed Nout, the operating point of the engine 200 is the operating point “e2”. And the operating point changes to “e3”.

  That is, in this case, the ECU 100 causes the engine 200 to operate at a desired operating point by causing the motor MG1 to function as a rotation speed control mechanism. The speed change mode corresponding to this state is the continuously variable speed change mode. In the continuously variable transmission mode, the operating point of the engine 200 (hereinafter referred to as “engine operating point”) is basically the engine operating point at which the fuel consumption rate of the engine 200 is minimized (hereinafter referred to as “optimum fuel consumption operating point”). Is called). The engine operating point in this case means one operating condition of the engine 200 defined by the combination of the engine speed Ne and the engine torque Te.

  Here, in the continuously variable transmission mode, the MG1 rotation speed Nmg1 needs to be variable. Therefore, when selecting the continuously variable transmission mode, the ECU 100 controls the lock mechanism 500 so that the sun gear S1 is in the unlocked state.

  In addition, in order to supply the engine direct torque Ter to the drive shaft OUT, the ECU 100 has the same magnitude as the torque Tes appearing on the sun gear shaft 310 that is the rotation shaft of the sun gear S1 and the sign is inverted according to the engine torque Te. A reaction torque (that is, a negative torque) is supplied from the motor MG1 to the sun gear shaft 310. In this case, at the operating point in the positive rotation region such as the operating point g1 or the operating point g2, the motor MG1 enters a power regeneration state (ie, a power generation state) with a positive rotating negative torque. In this way, in the continuously variable transmission mode, the ECU 100 causes the motor MG1 to function as a reaction force element, thereby supplying a part of the engine torque Te to the drive shaft OUT and the engine torque Te distributed to the sun gear shaft 310. Power regeneration (power generation) is performed in a part of When the torque required for the drive shaft OUT is insufficient in the engine direct torque Tor, the ECU 100 uses the regenerative power or appropriately takes out power from the battery 12 and appropriately takes the power from the motor MG2 to the drive shaft OUT. MG2 torque Tmg2 is supplied as assist torque.

  On the other hand, for example, when driving at a high speed and a light load, for example, under an operating condition where the engine speed Ne is low for a high output speed Nout, the motor MG1 becomes an operating point in a negative rotational range such as the operating point g3. . Since the motor MG1 outputs a negative torque as a reaction torque of the engine torque Te, in this case, the motor MG1 enters a state of negative rotation negative torque and enters a power running state. That is, in this case, the MG1 torque Tmg1 that is the input / output torque of the motor MG1 is transmitted to the drive shaft OUT as the drive torque of the hybrid vehicle 1. On the other hand, the ECU 100 controls the engine 200, the motor MG1, and the motor MG2 cooperatively so that the sum of the engine direct torque Ter and the MG2 torque Tmg2 matches the torque required by the driver. Therefore, when the motor MG1 falls into the power running state in this way, the motor MG2 is in a negative torque state because it absorbs excessive torque with respect to the required torque supplied to the drive shaft OUT. In this case, the motor MG2 enters a state of positive rotation and negative torque and enters a power regeneration state. In such a state, an inefficient electric path called so-called power circulation occurs in which the driving force from the motor MG1 is used for power regeneration in the motor MG2 and the motor MG1 is driven by this regenerative power. It will be. In the state where the power circulation occurs, the system efficiency of the hybrid drive device 10 decreases.

  Therefore, the ECU 100 controls the sun gear S1 to the locked state by the lock mechanism 500 in an operation region that is determined in advance as the possibility of such power circulation. Hereinafter, control in which the ECU 100 causes the sun gear S1 to transition from the unlocked state to the locked state is also referred to as “lock transition control”. This is shown in FIG. When the sun gear S1 shifts to the locked state by the lock mechanism 500, the operating point of the motor MG1 is fixed to the illustrated operating point “g4” corresponding to the rotational speed “0”.

  In this case, the remaining engine rotation speed Ne is uniquely fixed by the output rotation speed Nout and the 0 rotation, and the operation point becomes the illustrated operation point “e4”. That is, when the sun gear S1 is locked, the engine speed Ne is uniquely determined by the vehicle speed V and the unambiguous MG2 speed Nmg2. That is, in this case, the gear ratio is constant. The transmission mode corresponding to this state is the fixed transmission ratio mode.

  In the fixed gear ratio mode, the ECU 100 substitutes the reaction torque of the engine torque Te that should be borne by the motor MG1 by the physical engagement force of the lock mechanism 500. That is, in this case, the ECU 100 stops the motor MG1 because it is not necessary to control the motor MG1 in either the power regeneration state or the power running state. Therefore, basically, there is no need to operate the motor MG2, and the motor MG2 is in an idling state. Eventually, in the fixed gear ratio mode, the drive torque that appears on the drive shaft OUT is only the direct torque Ter that is divided on the drive shaft OUT side by the power split mechanism 300 out of the engine torque Te. Only the power transmission is performed, and the transmission efficiency is improved.

  In the fixed gear ratio mode, the ECU 100 does not necessarily stop the motor MG2. For example, the hybrid vehicle 1 is provided with various electric auxiliary devices, and appropriate electric power is required to drive the electric auxiliary devices. The motor MG2 may perform small-scale power regeneration in order to supply the battery 12 with power corresponding to the driving power. In this case, ECU 100 controls engine torque Te so that the directly achieved amount of engine torque Te is surplus with respect to the torque required to drive hybrid vehicle 1, and regenerates the surplus torque with motor MG2. In addition, when the driving torque is insufficient with only the engine direct torque Tor, the ECU 100 power-drives the motor MG2 and assists the driving torque with the MG2 torque Tmg2 as appropriate.

(Rotation control of motor MG1)
Next, a method for controlling the MG1 rotation speed Nmg1 performed by the ECU 100 when the motor MG1 is brought into the locked state will be specifically described. The ECU 100 fixes the MG1 rotation speed Nmg1 to 0 rpm by executing at least one of the following first to fourth embodiments during the lock transition control. Then, after that, the ECU 100 engages the lock mechanism 500 to place the motor MG1 in the locked state.

  Hereinafter, “rotating magnetic field control” refers to controlling the motor MG1 so that the rotor RO is rotationally driven by the rotating magnetic field of the stator ST, and “fixed magnetic field control” refers to the magnetic field of the stator ST. It means that the motor MG1 is controlled such that the rotation is restricted and the rotation of the rotor RO is restricted.

<First Embodiment>
First, control of the ECU 100 according to the first embodiment will be described. Schematically, in the first embodiment, the ECU 100 performs switching from rotating magnetic field control to fixed magnetic field control (also simply referred to as “control switching”) based on the timing when the MG1 rotation speed Nmg1 becomes 0 rpm. Thus, ECU 100 quickly shifts motor MG1 to the locked state even if the reaction force of engine 200 cannot be accurately grasped, and suppresses the occurrence of a shock due to the fluctuation of the inertia torque.

1. Time Chart FIG. 4 shows an example of a time chart of the MG1 rotation speed Nmg1 and the MG1 torque Tmg1 in the first embodiment. In FIG. 4, a graph “A1” indicates a time change of the MG1 rotation speed Nmg1 in the first embodiment, and a graph “A2” indicates the first comparative example, specifically, the MG1 rotation speed while continuing the rotating magnetic field control. The time change of MG1 rotation speed Nmg1 when the motor MG1 is brought into a locked state by feedback control of Nmg1 is shown. Further, the graph “A3” indicates the time change of the MG1 torque Tmg1 in the first embodiment. Details of the first comparative example corresponding to the graph A2 will be described in detail in a section “3. Effect” described later.

  First, the state of the motor MG1 at one point in the period “tw1” from the start of the lock transition control to the time “t2” will be described with reference to FIGS. FIG. 5A is a diagram showing the positional relationship between the magnetic pole (stator magnetic pole) Lst of the stator ST and the permanent magnet (rotor magnet) Lro of the rotor RO and the direction of various torques at one point in time tw1. FIG. 5B shows a graph of MG1 torque Tmg1 generated in the motor MG1 corresponding to the phase of the rotor magnet Lro (also referred to as “rotor magnet phase”) with respect to the stator magnetic pole Lst. The operating point “P1” indicates the MG1 torque Tmg1 generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  In the period tw1, the ECU 100 brings the MG1 rotation speed Nmg1 closer to “0” while executing the rotating magnetic field control. Specifically, as shown in FIG. 5 (a), the ECU 100 determines the torque Tes ("engine reaction force torque Tes") that is the reaction force torque of the engine 200 acting in the positive rotation direction indicated by the arrow "Y3". MG1 torque Tmg1 acting in the negative rotation direction indicated by the arrow “Y2” is made smaller than As a result, the torques corresponding to the arrows Y2 and Y3 cancel each other, and as a result, the predetermined torque indicated by the arrow “Y4” acts on the rotor RO in the forward rotation direction. The torque corresponding to the arrow Y4 is the width indicated by the arrow “Y5” in FIG.

  In addition, in the period tw1, inertia energy is generated in the negative rotation direction. Therefore, in the period tw1, the rotor RO is rotated in the negative rotation direction by the inertial energy while the inertial energy is decreased by the torque indicated by the arrow Y4 (see the arrow Y1).

  Next, the state of the motor MG1 at time “t2” corresponding to the time zone immediately before execution of control switching will be described with reference to FIGS. FIG. 6A is a diagram showing the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the directions of various torques at time t2. FIG. 6B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The operating point “P2” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  At time t2, the ECU 100 continues the rotating magnetic field control. In this case, the torque in the positive rotation direction acts on the rotor RO by a torque difference between the MG1 torque Tmg1 generated by the rotating magnetic field and the engine reaction force torque Tes (see arrows Y6 and Y7). At time t2, since the MG1 rotation speed Nmg1 is near 0, there is no inertial energy or it can be ignored.

  Next, the state of the motor MG1 at time “t3” corresponding to the time immediately after execution of control switching will be described with reference to FIGS. FIG. 7A shows the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the directions of various torques at time t3. FIG. 7B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The MG1 torque Tmg1 is a torque generated in the motor MG1 by a fixed magnetic field. The operating point “P3” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  ECU 100 detects that MG1 rotation speed Nmg1 has become “0” at time t3. In this case, the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control, and fixes the stator magnetic pole Lst. Thereby, MG1 torque Tmg1 and engine reaction force torque Tes balance and rotor RO stops. Specifically, the MG1 torque Tmg1 acts in the negative rotation direction, in other words, the direction in which the N pole or S pole of the rotor magnet Lro faces the S pole of the stator magnetic pole Lst (see arrow Y8). On the other hand, the engine reaction torque Tes is generated in the forward rotation direction of the rotor RO (see arrow Y9). As shown in FIG. 7B, the torques indicated by the arrows Y8 and Y9 are balanced.

  Further, at time t3, since the MG1 rotation speed Nmg1 is “0”, there is no inertial energy. After time t3, the MG1 torque Tmg1 and the engine reaction torque Tors continue to balance, and the MG1 rotation speed Nmg1 does not hunt and the inertia torque does not change. In this way, the ECU 100 switches the rotating magnetic field control to the fixed magnetic field control when the MG1 rotational speed Nmg1 becomes “0”, so that the motor MG1 can be quickly activated without accurately grasping the engine reaction force torque Tes. While being able to be in a locked state, the shock by the fluctuation | variation of the inertia torque after control switching can be suppressed.

  In the description of the time chart described above, the ECU 100 performs control switching when the MG1 rotation speed Nmg1 is converged from a negative value toward “0”. Not limited to this, the ECU 100 similarly performs control switching at the timing when the MG1 rotational speed Nmg1 becomes “0” even when the MG1 rotational speed Nmg1 converges from a positive value toward “0”.

2. Processing Flow Next, the processing procedure of the first embodiment will be described with reference to FIG. FIG. 8 is an example of a flowchart showing a processing procedure executed by the ECU 100 in the first embodiment. ECU 100 repeatedly executes the process of the flowchart shown in FIG. 8 according to a predetermined cycle.

  First, the ECU 100 acquires the MG1 rotation speed Nmg1 (step S101). Specifically, ECU 100 acquires MG1 rotation speed Nmg1 based on the detection signal of the rotation sensor corresponding to broken line frame A2 shown in FIG.

  Next, ECU 100 determines whether or not MG1 rotation speed Nmg1 is “0” (step S102). If the ECU 100 determines that the MG1 rotation speed Nmg1 is “0” (step S102; Yes), the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control (step S103). As a result, the ECU 100 limits the rotation of the rotor RO by fixing the direction of the magnetic field of the stator ST, and can quickly converge the MG1 rotation speed Nmg1 to 0 without accurately grasping the engine reaction torque Tors. it can.

  On the other hand, when it is determined that the MG1 rotation speed Nmg1 is not 0 (step S102; No), the MG1 torque Tmg1 is changed so as to change the MG1 rotation speed Nmg1 to 0 (step S104). In this case, the ECU 100 continues the rotating magnetic field control.

3. Effects Next, effects of the first embodiment will be described with reference to the first comparative example and the second comparative example.

  FIG. 9 shows an example of a time chart of the MG1 rotation speed Nmg1 and the MG1 torque Tmg1 in the first comparative example. In the first comparative example, during the lock transition control, the ECU 100 performs feedback control based on the deviation between the target value and the actual value of the MG1 rotation speed Nmg1 while continuing the rotating magnetic field control. Here, the ECU 100 estimates the engine reaction force torque Tes, and determines that the MG1 torque Tmg1 is smaller than the engine reaction force torque Tes when the MG1 rotation speed Nmg1 increases. On the other hand, when MG1 rotation speed Nmg1 decreases, ECU 100 determines that MG1 torque Tmg1 is larger than engine reaction force torque Tes.

  First, in the period “tw1” until the MG1 rotation speed Nmg1 reaches 0 after the control for locking the motor MG1 is started, the ECU 100 sets the MG1 rotation speed Nmg1 to “0” as in FIG. 5 of the first embodiment. Therefore, the MG1 torque Tmg1 acting in the negative rotation direction is made smaller than the engine reaction force torque Tes acting in the positive rotation direction. As a result, the rotor RO rotates in the negative rotation direction, and a predetermined torque is applied in the positive rotation direction. On the other hand, in the period tw1, inertial energy is generated in the negative rotation direction.

  Next, FIGS. 10A and 10B show the state of the motor MG1 during the period “tw2” from when the MG1 rotation speed Nmg1 passes “0” to when the MG1 torque Tmg1 passes the engine reaction torque Tes. It explains using. FIG. 10A is a diagram showing the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the direction of various torques at a certain point in the period tw2. FIG. 10B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The operating point “P4” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  As shown in FIG. 10B, in the period tw2, the force in the positive rotation direction due to the engine reaction force torque Tes is stronger than the force in the negative rotation direction due to the MG1 torque Tmg1. Therefore, as shown in FIGS. 10A and 10B, a force that increases the MG1 rotation speed Nmg1 corresponding to the torque difference (see arrow Y12) in the forward rotation direction acts on the rotor RO (see arrow Y10). . As a result, in the period tw2, the rotor RO rotates in the forward rotation direction (see arrow Y11), and inertia energy is generated in the forward rotation direction.

  Next, after the MG1 torque Tmg1 passes the engine reaction force torque Tes, the state of the motor MG1 in the period “tw3” in which the MG1 torque Tmg1 in the negative rotation direction is greater than the engine reaction force torque Tes in the positive rotation direction is shown in FIG. ) And (b). FIG. 11A is a diagram showing the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the directions of various torques at a certain point in the period tw3. FIG. 11B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The operating point “P5” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  As shown in FIG. 11B, in the period tw3, the force in the negative rotation direction by the MG1 torque Tmg1 is stronger than the force in the positive rotation direction by the engine reaction force torque Tes. As a result, as shown in FIGS. 11A and 11B, a force that causes the MG1 rotation speed Nmg1 corresponding to the torque difference (see arrow Y15) to transition in the negative rotation direction acts on the rotor RO (see arrow Y13). ). Further, in the period tw3, inertial energy in the forward rotation direction continues to exist from the period tw2, and thereby the rotor RO rotates in the forward rotation direction while gradually decreasing (see arrow Y14).

  Next, the state of the motor MG1 in the period “tw4” after the MG1 rotation speed Nmg1 converges to “0” will be described with reference to FIGS. FIG. 12A is a diagram showing the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the direction of various torques at a certain point in the period tw4. FIG. 12B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The operating point “P6” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  As shown in FIG. 12B, in the period tw4, the force in the positive rotation direction (see arrow Y16) by the engine reaction force torque Tes balances the force in the negative rotation direction by the MG1 torque Tmg1 (see arrow Y17). The torque difference is “0”. In the period tw4, the MG1 rotation speed Nmg1 is “0”, and the motor MG1 is locked.

  Thus, in the first comparative example, the ECU 100 controls the motor MG1 based on the change in the MG1 rotation speed Nmg1 while estimating the engine reaction force torque Tes. However, in the first comparative example, when the change width of the MG1 rotation speed Nmg1 is large, it takes time for the MG1 rotation speed Nmg1 to converge to “0”. Similarly, when the deviation between the command value and the actual value of the engine torque Te is large, it takes time to accurately estimate the engine reaction force torque Tes. Therefore, it takes time for the MG1 rotation speed Nmg1 to converge to “0”. Cost.

  Considering the above, in the first embodiment, the ECU 100 switches the rotating magnetic field control to the fixed magnetic field control at the timing when the MG1 rotational speed Nmg1 becomes “0”, thereby converging the MG1 rotational speed Nmg1 to “0”. Therefore, the ECU 100 does not depend on the change width of the MG1 rotation speed Nmg1 and does not depend on the deviation between the command value and the actual value of the engine torque Te, that is, without accurately grasping the engine reaction force torque Tes. The rotational speed Nmg1 can be quickly converged to “0”.

  Next, a second comparative example will be described with reference to FIGS.

  FIG. 13 shows an example of a time chart of the MG1 rotation speed Nmg1 and the MG1 torque Tmg1 in the second comparative example. In FIG. 13, the graph “A5” corresponds to the time change of the MG1 rotation speed Nmg1 in the second comparative example, and the graph “A6” corresponds to the time change of the MG1 torque Tmg1 in the second comparative example. In the second comparative example, the ECU 100 performs control switching at a timing when the MG1 rotation speed Nmg1 is not “0”.

  First, in the period “tw11” from the start of the control for locking the motor MG1 to just before the control switching, the ECU 100 approaches the MG1 rotation speed Nmg1 to “0” as in the period tw1 of the first comparative example. The MG1 torque Tmg1 acting in the negative rotation direction is made smaller than the engine reaction force torque Tes acting in the positive rotation direction. In addition, in the period tw11, inertial energy is generated in the negative rotation direction. As a result, the rotor RO rotates in the negative rotation direction, and a predetermined torque is applied in the positive rotation direction.

  Next, the state of the motor MG1 at time “t4” corresponding to immediately after execution of control switching will be described with reference to FIGS. FIG. 14A is a diagram showing the positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and the directions of various torques at time t4. FIG. 14B shows a graph of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase. The operating point “P7” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  As shown in FIG. 14B, at time t4, the engine reaction force torque Tes and the MG1 torque Tmg1 become equal. On the other hand, as shown in FIG. 14A, the MG1 rotation speed Nmg1 is negative (see arrow Y21), and inertia energy is generated in the negative rotation direction.

  The state of the motor MG1 in the period “tw12” after time t4 will be described with reference to FIGS. FIG. 15A is a diagram showing a positional relationship between the stator magnetic pole Lst and the rotor magnet Lro and directions of various torques at an initial time point in the period tw12. FIG. 15B shows a graph of MG1 torque Tmg1 generated in motor MG1 corresponding to each rotor magnet phase. The operating point “P8” indicates the torque generated in the motor MG1 in the case of the rotor magnet phase shown in FIG.

  As shown in FIG. 15A, at the initial stage of the period tw12, the MG1 rotation speed Nmg1 is negative (see arrow Y23). Therefore, as shown in FIG. 15B, the rotor RO rotates to the negative side due to the inertial energy in the negative rotation direction, and the MG1 torque Tmg1 applied to the rotor RO is reduced by the fixed magnetic field control. As a result, as shown in FIG. 15 (a), the rotor RO is subjected to a torque in the forward rotation direction (see arrow Y22). Thereafter, the MG1 rotation speed Nmg1 becomes positive, and further hunting is continued until the period tw12 ends.

  In the period tw12, as shown in FIG. 13, ECU 100 controls MG1 rotation speed Nmg1 in a state where the magnetic field direction of stator ST is fixed, and therefore cannot grasp MG1 torque Tmg1 generated in motor MG1. Therefore, during this period, the ECU 100 cannot calculate the engine direct delivery torque Ter based on the MG1 torque Tmg1 and cannot identify the shortage of the driving force. Therefore, the ECU 100 cannot compensate for the driving force using the motor MG2 during this period, and cannot suppress fluctuations in the driving force.

  In consideration of the above, in the first embodiment, the ECU 100 can not grasp the MG1 torque Tmg1 during the lock transition control by switching from the rotating magnetic field control to the fixed magnetic field control when the MG1 rotation speed Nmg1 becomes “0”. And the compensation of the driving force by the motor MG2 can be executed with high accuracy. Further, ECU 100 prevents hunting of engine speed Ne and MG1 rotation speed Nmg1 after control switching, and suppresses fluctuations of inertia torque based on the rotation speed fluctuations.

Second Embodiment
In the second embodiment, in addition to the first embodiment, when changing the MG1 rotation speed Nmg1 to “0” during the lock transition control, the ECU 100 changes the current MG1 rotation speed Nmg1 to a value that crosses “0”. A target value of MG1 rotation speed Nmg1 (hereinafter referred to as “target rotation speed Nmg1 *”) is set. Thereby, ECU 100 shortens the time required from the start of the lock transition control to the control switching, and quickly sets motor MG1 in the locked state.

  FIG. 16A shows a graph of the time change of the MG1 rotation speed Nmg1 when the MG1 rotation speed Nmg1 is negative during the lock transition control and the target rotation speed Nmg1 * is set to “0”. FIG. 16B shows the time change of the MG1 rotation speed Nmg1 when the MG1 rotation speed Nmg1 is a negative value during the lock transition control and the target rotation speed Nmg1 * is set to a predetermined positive value (for example, 50 rpm). The graph of is shown.

  As shown in FIG. 16 (a), when the target rotational speed Nmg1 * is set to a value that does not cross “0” from the actual value of the MG1 rotational speed Nmg1, the MG1 rotational speed Nmg1 gradually becomes “0”. Head. At time “t5”, the MG1 rotation speed Nmg1 becomes “0”, and the ECU 100 performs control switching.

  On the other hand, in the second embodiment, ECU 100 sets target rotational speed Nmg1 * to a value that crosses “0” from the actual value of MG1 rotational speed Nmg1. As a result, as shown in FIG. 16B, the MG1 rotation speed Nmg1 increases more rapidly toward “0”. In this case, MG1 rotation speed Nmg1 becomes “0” at time “t6” earlier than time t5, and ECU 100 performs control switching at time t6.

  Thus, ECU 100 sets target rotational speed Nmg1 * to a value that crosses “0” from the actual value of MG1 rotational speed Nmg1. The specific value of the target rotation speed Nmg1 * is determined by, for example, experiments and stored in the memory of the ECU 100 in advance. By doing in this way, ECU100 can shorten the time which lock transition control requires, and can make motor MG1 into a locked state rapidly.

  Further, even when the MG1 rotation speed Nmg1 is a positive value at the time of lock transition control, the ECU 100 is a value that crosses “0” from the actual value of the MG1 rotation speed Nmg1 (for example, −50 rpm), as in the case of the negative value described above. ) Is set to the target rotational speed Nmg1 *. Thus, ECU 100 can shorten the time required for the lock transition control and promptly put motor MG1 in the locked state even when MG1 rotation speed Nmg1 goes from a positive value to “0”.

  Next, a processing flow in the second embodiment will be described with reference to FIG. FIG. 17 is an example of a flowchart showing a processing procedure executed by the ECU 100 in the second embodiment. ECU 100 repeatedly executes the process of the flowchart shown in FIG. 17 according to a predetermined cycle.

  First, the ECU 100 acquires the MG1 rotation speed Nmg1 (step S201). Specifically, ECU 100 acquires MG1 rotation speed Nmg1 based on the detection signal of the rotation sensor corresponding to broken line frame A2 shown in FIG. Next, ECU 100 determines whether or not MG1 rotation speed Nmg1 is “0” (step S202). If the ECU 100 determines that the MG1 rotation speed Nmg1 is “0” (step S202; Yes), the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control (step S203). As a result, the ECU 100 limits the rotation of the rotor RO by fixing the direction of the magnetic field of the stator ST, and can quickly converge the MG1 rotation speed Nmg1 to 0 without accurately grasping the engine reaction torque Tors. it can.

  On the other hand, when ECU 100 determines that MG1 rotation speed Nmg1 is not “0” (step S202; No), ECU 100 determines whether MG1 rotation speed Nmg1 is greater than 0 (step S204). When ECU 100 determines that MG1 rotation speed Nmg1 is greater than 0 (step S204; Yes), ECU 100 sets target rotation speed Nmg1 * to a negative value (step S205). In other words, ECU 100 changes MG1 torque Tmg1 so as to change MG1 rotation speed Nmg1 to a negative value. On the other hand, when ECU 100 determines that MG1 rotation speed Nmg1 is not greater than 0 (step S204; No), that is, when it is determined that MG1 rotation speed Nmg1 is less than 0, target rotation speed Nmg1 * is set to a positive value. (Step S206). In this way, the ECU 100 sets the target rotation speed Nmg1 * to a value that crosses “0” from the actual value of the MG1 rotation speed Nmg1, thereby preventing the control switching timing from being delayed and promptly locking the motor MG1. Can be.

<Third Embodiment>
In the third embodiment, in addition to the first and second embodiments, the ECU 100 uses the torque applied to the rotation shaft of the motor MG1 such as the engine reaction force torque Tes (“ And MG1 axis torque ”) and the fluctuation range of the torque immediately before the control switching (hereinafter referred to as“ torque fluctuation range Tw ”). Specifically, the ECU 100 sets the magnetic field strength of the stator ST in the fixed magnetic field control to be weaker as the MG1 axis torque just before the control switching is smaller, and to be weaker as the torque fluctuation width Tw is smaller. Thus, ECU 100 appropriately sets the magnetic field after the control switching to stop MG1 rotation speed Nmg1 at “0” and suppresses a loss caused by unnecessarily increasing the magnetic field.

  This will be specifically described with reference to FIG. 18A and 18B show graphs of the MG1 torque Tmg1 generated in the motor MG1 corresponding to each rotor magnet phase in the fixed magnetic field. FIG. 18B corresponds to the case where the torque fluctuation width Tw in the predetermined time width immediately before the control switching is smaller than in the case of FIG. The operating points “P10” and “P11” indicate the operating point of each MG1 torque Tmg1 at the time of control switching (immediately before).

  The ECU 100 sets the strength of the fixed magnetic field set in the case of FIG. 18B to be weaker than the fixed magnetic field set in the case of FIG. In other words, the ECU 100 sets the magnetic field of the stator ST after the control switching to be weaker as the torque fluctuation range Tw is smaller.

  FIG. 19 is an example of a table showing the relationship between the strength of the fixed magnetic field and the torque fluctuation range Tw after the ECU 100 switches control. As shown in FIG. 19, the strength of the fixed magnetic field after the control switching is set to be weaker as the torque fluctuation range Tw is smaller and stronger as the torque fluctuation range Tw is larger. In addition to the torque fluctuation range Tw, the strength of the fixed magnetic field is set to be weaker as the MG1 axis torque immediately before the control switching is smaller and to be stronger as the MG1 axis torque is larger.

  Considering the above, the ECU 100 stores in advance a map of the MG1 axis torque immediately before the control switching, the torque fluctuation range Tw, the strength of the fixed magnetic field, and the like in a memory. The above-described map and the like are created in advance based on experiments and the like. Then, ECU 100 refers to the above-described map and the like, and sets the strength of the fixed magnetic field based on the MG1 axis torque and the torque fluctuation range Tw immediately before the control switching. Thus, ECU 100 can stably stop motor MG1 at 0 rpm without excessively increasing the strength of the magnetic field after control switching. In addition, the ECU 100 can suppress energy loss caused by setting a fixed magnetic field strongly unnecessarily.

  Here, a method for obtaining the torque fluctuation range Tw will be specifically described. For example, ECU 100 shakes (varies) with respect to the average (simply referred to as “average rotational speed change rate AdN”) of the change rate (simply referred to as “rotational speed change rate dN”) of MG1 rotational speed Nmg1 immediately before the control switching. The torque fluctuation range Tw is estimated based on the width (also simply referred to as “rotational speed fluctuation range dNw”). Specifically, ECU 100 obtains torque fluctuation range Tw by referring to equation (4) obtained by modifying equation (3), which is an equation representing MG1 axis torque. Here, “Ig” indicates the moment of inertia of the motor MG1, and “Tx” indicates the torque excluding the torque that is consumed for the change in the engine speed Ne among the engine torque Te. Expression (4) corresponds to the difference of Expression (3).

Ig × dN = Tmg1 + P / (1 + P) × Tx Formula (3)
Tw = P / (1 + P) × (variation width of Tx) = Ig × dNw Formula (4)
In this way, the ECU 100 obtains the torque fluctuation range Tw from the inertia moment Ig and the rotational speed fluctuation range dNw with reference to the equation (4). The moment of inertia Ig is determined in advance based on, for example, experiments, and is stored in the memory of the ECU 100.

  Next, an example of a method for calculating the rotation speed fluctuation range dNw will be described. First, the ECU 100 calculates the average speed change rate dN during a period including at least one compression / expansion process of the engine 200, for example, if the engine 200 is a general in-line four-cylinder engine, the period of ½ engine rotation or more. The average of the rotational speed change rate dN is calculated as the average rotational speed change rate AdN. Then, the ECU 100 determines the rotation speed fluctuation range dNw as the difference between the maximum and minimum values of the rotation speed change rate dN and the average rotation speed change rate AdN in a period including one or more compression / expansion steps of the engine 200, that is, The difference between the maximum value and the minimum value of the rotational speed change rate dN used for calculating the average rotational speed change rate AdN and the average rotational speed change rate AdN is determined. Specifically, the rotational speed fluctuation range dNw is either the difference between the above-mentioned maximum value and the average rotational speed change rate AdN, the difference between the above-mentioned minimum value and the average rotational speed change rate AdN, or these Is set to the sum of

  In addition to the above processing, the ECU 100 preferably takes into consideration that the torque fluctuation range Tw becomes larger at low engine revolutions Ne than at high revolutions due to the design of the engine 200 and the damper. The width Tw may be corrected based on the engine speed Ne. In this case, assuming that the correction rate multiplied by the torque fluctuation range Tw is “correction rate Ra”, the ECU 100 calculates the torque fluctuation range Tw with reference to the following formula (5) instead of the formula (4).

Tw = Ig × dNw × Ra Formula (5)
FIGS. 20A and 20B show tables of the correction rate Ra by which the torque fluctuation range Tw corresponding to the engine speed Ne is multiplied. Specifically, FIG. 20A corresponds to a table (also referred to as a “high rotation change correction table”) used when the MG1 rotation speed Nmg1 is shifted from a negative value to “0” during lock transition control. FIG. 20B corresponds to a table (also referred to as a “low rotation change correction table”) used when the MG1 rotation speed Nmg1 is shifted from a positive value to “0” during lock transition control. The tables shown in FIGS. 20A and 20B are created in advance based on, for example, experiments and stored in the memory of the ECU 100 in advance.

  When the MG1 rotation speed Nmg1 is a negative value during the lock transition control, the ECU 100 refers to the high rotation change correction table shown in FIG. 20A, and the correction rate Ra is decreased as the engine rotation speed Ne is lower. The correction rate Ra is set to be larger as the engine speed Ne is higher. In this case, the correction rate Ra is set to a value of approximately 1 or less.

  On the other hand, when the MG1 rotation speed Nmg1 is a positive value during the lock transition control, the ECU 100 refers to the low rotation change correction table shown in FIG. 20B, and increases the correction rate Ra as the engine rotation speed Ne decreases. The correction rate Ra is set to be smaller as the engine speed Ne is higher. In this case, the correction rate Ra is set to a value of approximately 1 or more.

  Thus, the ECU 100 sets the correction factor Ra based on the engine speed Ne. The ECU 100 determines the correction factor Ra so that the torque fluctuation range Tw is reduced when increasing the MG1 rotation speed Nmg1 from a negative value to “0” during the lock transition control, and sets the MG1 rotation speed Nmg1 during the lock transition control. When the value is decreased from the positive value to “0”, the correction factor Ra is determined so that the torque fluctuation range Tw is increased.

  Next, the processing flow of the third embodiment will be described with reference to FIGS. FIG. 21 is an example of a flowchart showing a processing procedure executed by the ECU 100 in the third embodiment. ECU 100 repeatedly executes the process of the flowchart shown in FIG. 21 according to a predetermined cycle.

  First, the ECU 100 acquires the MG1 rotation speed Nmg1 (step S301). Next, ECU 100 determines whether or not MG1 rotation speed Nmg1 is “0” (step S302).

  If the ECU 100 determines that the MG1 rotation speed Nmg1 is “0” (step S302; Yes), the ECU 100 determines the strength of the rotating magnetic field (step S303). Specifically, the ECU 100 sets the magnetic field of the stator ST at the time of fixed magnetic field control to be weaker as the torque fluctuation range Tw obtained in step S305 described later is smaller. Then, ECU 100 switches from rotating magnetic field control to fixed magnetic field control (step S304). Thereby, the ECU 100 can stably stop the motor MG1 at 0 rpm without excessively increasing the strength of the magnetic field after the control switching, and suppresses energy loss caused by setting a strong fixed magnetic field unnecessarily. be able to.

  On the other hand, when the ECU 100 determines that the MG1 rotation speed Nmg1 is not “0” (step S302; No), the ECU 100 performs a process of acquiring the torque fluctuation range Tw (step S305). The specific processing contents will be described with reference to the flowchart of FIG. Then, ECU 100 changes MG1 torque Tmg1 so as to change MG1 rotation speed Nmg1 to 0 (step S306).

  FIG. 22 is an example of a flowchart illustrating a processing procedure for obtaining the torque fluctuation range Tw in step S305. The ECU 100 executes the flowchart shown in FIG. 22 when the process proceeds to step S305.

  First, ECU 100 calculates a rotational speed change rate dN of MG1 rotational speed Nmg1 (step S401). Specifically, ECU 100 calculates rotation speed change rate dN by calculating a difference between MG1 rotation speeds Nmg1 acquired at regular intervals.

  Then, the ECU 100 calculates an average rotational speed change rate AdN of the rotational speed change rate dN (step S402). For example, the ECU 100 determines the average value of the rotational speed change rate dN within a period including at least one compression / expansion process of the engine 200 as the average rotational speed change rate AdN.

  Next, the ECU 100 calculates a rotational speed fluctuation range dNw based on the average rotational speed change rate AdN (step S403). Specifically, the ECU 100 determines the fluctuation range of the rotational speed change rate dN relative to the average rotational speed change rate AdN in the period for which the average rotational speed change rate AdN is obtained as the rotational speed fluctuation range dNw. Then, the ECU 100 acquires the engine speed Ne (step S404).

  Next, ECU 100 determines whether or not MG1 rotation speed Nmg1 is less than 0 (step S405). When the ECU 100 determines that the MG1 rotation speed Nmg1 is less than 0 (step S405; Yes), that is, when the MG1 rotation speed Nmg1 is changed from a negative value to “0” during the lock transition control, the high rotation speed change is performed. The correction rate Ra is calculated with reference to the hour correction table (step S406). For example, in this case, the ECU 100 refers to the table shown in FIG. 20A and specifies the correction factor Ra based on the engine speed Ne. On the other hand, when the ECU 100 determines that the MG1 rotation speed Nmg1 is not less than 0 (step S405; No), that is, when the MG1 rotation speed Nmg1 transitions from a positive value to “0” during the lock transition control, the low rotation change The correction rate Ra is calculated with reference to the hour correction table (step S407). Specifically, in this case, the ECU 100 refers to the table shown in FIG. 20B and specifies the correction factor Ra based on the engine speed Ne.

  Then, after executing step S406 or step S407, the ECU 100 calculates a torque fluctuation range Tw (step S408). Specifically, the ECU 100 refers to the equation (5), and determines a value obtained by multiplying the moment of inertia Ig, the rotational speed fluctuation range dNw, and the correction factor Ra as the torque fluctuation range Tw. As a result, the ECU 100 can accurately estimate the torque fluctuation range Tw, and can accurately set the strength of the rotating magnetic field in step S303 in FIG.

<Fourth embodiment>
In the fourth embodiment, in addition to the first to third embodiments, the ECU 100 performs control switching when changing the MG1 rotation speed Nmg1 to “0” in accordance with a request from the driver, a vehicle state, and the like. Judge whether or not. The ECU 100 does not perform control switching when there is a possibility that the fixed magnetic field after the control switching cannot be generated with sufficient strength. Thus, ECU 100 determines in advance whether lock transition control by control switching is possible, prevents a fixed magnetic field from being generated after control switching, prevents MG1 rotation speed Nmg1 from being set to “0”, and lock transition control. Is restrained from prolonging.

  This will be described in more detail with two specific examples.

  In the first example, the ECU 100 performs the rotating magnetic field control when the upper limit value of the output of the battery 12 (also referred to as “discharge allowable power Wout”), which is the power that can be taken out by the battery 12, is lower than a predetermined value. Continue to perform lock transition control. Thereby, the ECU 100 prevents the fixed magnetic field from being generated after the control is switched.

  Here, the ECU 100 preferably determines the above-described predetermined value as a predicted value of power consumption during fixed magnetic field control. Then, ECU 100 determines that there is a high possibility that electric power sufficient to generate a strong fixed magnetic field in motor MG1 cannot be taken out from battery 12 when discharge allowable power Wout is lower than an expected value of power consumption during fixed magnetic field control. To do.

  Next, a method for calculating a predicted value of power consumption during fixed magnetic field control will be described. As will be described later, the ECU 100 predicts the power consumption of the motor MG2 at the time of fixed magnetic field control (hereinafter referred to as “expected motor power consumption Wm”) and the power consumption of the motor MG1 at the time of fixed magnetic field control (hereinafter referred to as “predicted power consumption Wm”) , Called “expected generator power consumption Wg”) as a predicted value of power consumption during fixed magnetic field control.

  Here, in order to calculate the expected motor power consumption Wm, the ECU 100 first refers to a predetermined map or the like based on the vehicle speed V and the accelerator opening degree Ta, and calculates the required power (driver required power) based on the operation of the driver. Ask. Next, the ECU 100 refers to a predetermined map or the like and obtains the output power of the engine 200 based on the engine speed Ne and the driver required power when the MG1 speed Nmg1 determined by the vehicle speed V is “0”. Then, ECU 100 refers to a predetermined map or the like and obtains the output power of motor MG2 based on the driver requested power and the output power of engine 200. Then, the ECU 100 refers to a predetermined map or the like and obtains an expected motor power consumption Wm based on the motor output power. The above-described map or the like is created in advance based on, for example, experiments and stored in the memory of the ECU 100.

  ECU 100 also calculates predicted generator power consumption Wg based on the strength of the fixed magnetic field required by motor MG1. Here, the ECU 100 refers to a predetermined map or the like in order to determine the required fixed magnetic field strength, and the engine speed Ne when the MG1 speed Nmg1 determined by the vehicle speed V is “0”, and the output of the engine 200 Based on the power, the engine torque Te is obtained. Then, the ECU 100 refers to a predetermined map or the like, determines the required fixed magnetic field strength based on the engine torque Te, and obtains the expected generator power consumption Wg based on the fixed magnetic field strength. The above-described map or the like is created in advance based on, for example, experiments and stored in the memory of the ECU 100.

  In the second example, the ECU 100 switches the control when the predicted value of the limit value of the current allowable by the motor MG1 (hereinafter referred to as “predicted generator limit current Iglim”) is smaller than a predetermined value. Without the rotation, the rotating magnetic field control is continued and the lock transition control is performed. Specifically, the ECU 100 refers to a predetermined map or the like, obtains an expected generator limit current Iglim based on the temperature of the motor MG1, the inverter temperature, and the inverter cooling water temperature acquired from various sensors, and this is smaller than a predetermined value. It is determined whether or not.

  In general, when the temperature of the motor MG1, the inverter temperature, the inverter cooling water temperature, etc. are high, the allowable current of the motor MG1 is small, and the possibility that the current necessary for generating the fixed magnetic field cannot be supplied to the motor MG1 increases. . In consideration of the above, when the expected generator limit current Iglim is smaller than a predetermined value, the ECU 100 does not generate a fixed magnetic field after control switching by continuing the rotating magnetic field control and performing the lock transition control. Suppress.

  Preferably, ECU 100 sets the above-mentioned predetermined value to a predicted value of a current that flows to motor MG1 necessary for generating a fixed magnetic field (hereinafter referred to as “predicted generator required current Ig *”). To do. That is, in this case, when the expected generator limit current Iglim is lower than the expected generator required current Ig *, the ECU 100 continues the rotating magnetic field control and performs the lock transition control.

  Here, a method of calculating the expected generator required current Ig * will be described. First, the ECU 100 calculates the driver required power based on the vehicle speed V and the accelerator opening degree Ta. In addition, ECU 100 obtains the output power of engine 200 from the engine speed Ne and the driver required power when MG1 speed Nmg1 determined by vehicle speed V is “0”. Then, ECU 100 obtains engine torque Te from the engine speed Ne and the output power of engine 200 when MG1 speed Nmg1 determined by vehicle speed V is “0”. Then, the ECU 100 obtains the required fixed magnetic field strength from the engine torque Te described above, and determines the expected generator required current Ig * based on the fixed magnetic field strength.

  Next, the processing flow of the fourth embodiment will be described with reference to FIGS.

  FIG. 23 is an example of a flowchart illustrating a processing procedure executed by the ECU 100 in the fourth embodiment. ECU 100 repeatedly executes the processing of the flowchart shown in FIG. 23 according to a predetermined cycle.

  First, the ECU 100 acquires the MG1 rotation speed Nmg1 (step S501). Next, the ECU 100 determines whether control switching can be performed (step S502). Specifically, in this case, ECU 100 executes either the process of the flowchart shown in FIG. 24 or the process of the flowchart shown in FIG. These specific processing procedures will be described later.

  Then, ECU 100 determines whether or not control switching is possible based on the determination that control switching can be performed (step S503). If ECU 100 determines that control switching is possible (step S503; Yes), the process proceeds to step S504. On the other hand, when ECU 100 determines that control switching is not possible (step S503; No), it changes MG1 torque Tmg1 so as to change MG1 rotation speed Nmg1 to “0” (step S506). Therefore, in this case, the ECU 100 does not perform control switching during the lock transition control, and continues the rotating magnetic field control.

  Next, the ECU 100 determines whether or not the MG1 rotation speed Nmg1 is “0” in step S504 (step S504). If the ECU 100 determines that the MG1 rotation speed Nmg1 is “0” (step S504; Yes), the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control (step S505). On the other hand, when ECU 100 determines that MG1 rotation speed Nmg1 is not “0” (step S504; No), it changes MG1 torque Tmg1 to change MG1 rotation speed Nmg1 to “0” (step S506).

  FIG. 24 is a flowchart illustrating an example of a processing procedure for determining whether control switching can be performed in step S502 of FIG. ECU 100 executes the process of the flowchart shown in FIG. 24 when the process proceeds to step S502.

  First, the ECU 100 acquires discharge allowable power Wout (step S601). For example, the ECU 100 specifies the discharge allowable power Wout based on, for example, a detection signal of a temperature sensor attached to the battery 12 or a SOC (State Of Charge) sensor. Then, ECU 100 calculates expected motor power consumption Wm (step S602). Next, the ECU 100 calculates the expected generator power consumption Wg (step S603).

  Next, ECU 100 determines whether discharge allowable power Wout is equal to or greater than the sum of expected motor power consumption Wm and expected generator power consumption Wg (step S604). Thereby, ECU100 determines whether the power consumption at the time of changing to fixed magnetic field control does not exceed discharge allowable power Wout. When ECU 100 determines that discharge allowable power Wout is equal to or greater than the sum of expected motor power consumption Wm and expected generator power consumption Wg (step S604; Yes), ECU 100 determines that control switching is possible (step). S605). Then, as shown in the flowchart of FIG. 23, when the MG1 rotation speed Nmg1 becomes “0” (step S504; Yes), the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control (step S505). Thereby, the ECU 100 can execute the lock transition control promptly and reliably.

  On the other hand, when ECU 100 determines that discharge allowable power Wout is less than the sum of expected motor power consumption Wm and expected generator power consumption Wg (step S604; No), CPU 100 determines that control switching is impossible (step S604). Step S605). That is, in this case, the ECU 100 determines that there is a possibility that the electric power for generating the fixed magnetic field necessary for the motor MG1 is insufficient after the control is switched. In this case, ECU 100 continues the rotating magnetic field control in step S506 of FIG. 23, and feedback-controls MG1 rotation speed Nmg1.

  FIG. 25 is a flowchart showing another example of the processing procedure for determining whether control switching can be performed in step S502 of FIG. ECU 100 executes the process of the flowchart shown in FIG. 24 when the process proceeds to step S502.

  First, the ECU 100 calculates the expected generator limit current Iglim (step S701). Next, the ECU 100 calculates the expected generator required current Ig * (step S702). Then, the ECU 100 determines whether or not the predicted generator limit current Iglim is equal to or greater than the predicted generator required current Ig * (step S703). Thereby, ECU 100 determines whether or not a sufficient current can be supplied to motor MG1 when transitioning to fixed magnetic field control. If the ECU 100 determines that the expected generator limit current Iglim is equal to or greater than the expected generator required current Ig * (step S703; Yes), the ECU 100 determines that control switching is possible (step S704). Then, as shown in the flowchart of FIG. 23, when the MG1 rotation speed Nmg1 becomes “0” (step S504; Yes), the ECU 100 switches from the rotating magnetic field control to the fixed magnetic field control (step S505). Thereby, the ECU 100 can execute the lock transition control promptly and reliably.

  On the other hand, when the ECU 100 determines that the expected generator limit current Iglim is less than the expected generator required current Ig * (step S703; No), the ECU 100 determines that control switching is impossible (step S705). That is, in this case, ECU 100 determines that there is a possibility that a current sufficient to generate a fixed magnetic field necessary for motor MG1 may not be set after control switching. In this case, ECU 100 continues the rotating magnetic field control in step S506 of FIG. 23, and feedback-controls MG1 rotation speed Nmg1.

[Modification]
Next, modified examples of the first to fourth embodiments will be described. The modifications shown below may be arbitrarily combined and applied to the above-described embodiment.

(Modification 1)
In the first embodiment, the ECU 100 performs control switching at a timing when the MG1 rotation speed Nmg1 becomes “0”. However, the method to which the present invention is applicable is not limited to this. Instead of this, the ECU 100 may execute control switching at a timing when the MG1 rotation speed Nmg1 becomes substantially zero. Specifically, in this case, the ECU 100, for example, when the MG1 rotation speed Nmg1 is 0 or a value corresponding to 0, that is, the MG1 rotation speed Nmg1 falls within a range of values that exhibit the same effects as the first embodiment. Switch control to. The above-described range is determined in advance based on experiments or the like, for example, and stored in the memory of the ECU 100. And ECU100 makes motor MG1 a locked state by engaging the lock mechanism 500 after performing control switching. This also allows ECU 100 to quickly lock motor MG1 even if the reaction force of engine 200 cannot be accurately grasped.

(Modification 2)
In the second embodiment, the ECU 100 sets the target rotational speed Nmg1 * so that the MG1 rotational speed Nmg1 crosses “0” during the lock transition control. In addition to this control, the ECU 100 determines whether the MG1 rotation speed Nmg1 does not cross “0” based on the change in the rotation speed change rate (rotation speed change rate dN) during the change of the MG1 rotation speed Nmg1. You may judge. Then, ECU 100 sets target rotation speed Nmg1 * such that MG1 rotation speed Nmg1 crosses “0” only when it is determined that MG1 rotation speed Nmg1 does not cross “0”.

  For example, the ECU 100 monitors the rotation speed change rate dN in a predetermined time width immediately before the lock transition control, and only when the change in the rotation speed change rate dN is equal to or less than a predetermined value, from the actual value of the MG1 rotation speed Nmg1 The target rotational speed Nmg1 * is set to a value that crosses “0”. The predetermined time width and the predetermined value described above are determined in advance based on experiments or the like, for example, and are stored in the memory of the ECU 100.

(Modification 3)
In the third embodiment, the ECU 100 calculates the torque fluctuation range Tw based on the fluctuation width (rotation speed fluctuation width dNw) with respect to the average rotation speed change rate AdN. Instead of this, the ECU 100 may calculate the torque fluctuation range Tw based on a change in the engine speed Ne. In this case, for example, the ECU 100 calculates the rate of change of the engine speed Ne in the torque fluctuation range acquisition process of step S305 of FIG. 21, and specifies the torque fluctuation range Tw with reference to a predetermined map or the like from the change rate. . The above-described map or the like is determined based on, for example, experiments in advance and stored in the memory of the ECU 100.

(Modification 4)
In the fourth embodiment, the ECU 100 performs the lock transition control by continuing the rotating magnetic field control for performing the control switching when the discharge allowable power Wout is equal to or less than a predetermined value. Instead of this, when the state of charge (SOC) of the battery 12 is equal to or less than a predetermined value, the ECU 100 may continue the rotating magnetic field control for performing the control switching and perform the lock transition control. The predetermined value described above may be either a predetermined value based on an experiment or the like or a dynamically determined value. In the latter case, the predetermined value is determined, for example, as the SOC required to execute the fixed magnetic field control and set the MG1 rotation speed Nmg1 to “0”. The SOC is an example of the “state quantity corresponding to the storage state” according to the present invention, and is quantified assuming that the fully discharged state is 0 (%) and the fully charged state is 100 (%). This also preferably prevents the ECU 100 from generating a fixed magnetic field after switching the control, and prevents the MG1 rotation speed Nmg1 from being set to “0” and the lock transition control from being prolonged.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 10 Hybrid drive device 12 Battery 100 ECU
200 Engine 300 Power split mechanism 400 Input shaft 500 Lock mechanism 600 MG2 reduction mechanism

Claims (6)

An internal combustion engine;
A rotating electric machine capable of rotating the rotor by a rotating magnetic field of the stator and transmitting power to the rotating shaft;
A plurality of rotational elements capable of differentially rotating with each other, including a first rotational element coupled to the internal combustion engine, a second rotational element coupled to the rotating electrical machine, and a third rotational element coupled to a drive shaft A differential mechanism having
Locking means for locking the rotation of the rotating electrical machine;
In the case where the rotating electrical machine is locked by the locking means, and the rotational speed of the rotating electrical machine becomes substantially 0 by controlling the rotating electrical machine, the control of the rotating electrical machine is controlled by the rotating magnetic field of the stator. Fixed magnetic field control for controlling the rotating electric machine so as to limit the rotation of the rotor by fixing the direction of the magnetic field of the stator from rotating magnetic field control for controlling the rotating electric machine so that the rotor is driven to rotate. Control means for switching to,
A control apparatus for a hybrid vehicle, comprising:   2. The hybrid vehicle according to claim 1, wherein, when the rotating electrical machine is locked by the locking unit, the control unit sets a target value of the rotational speed of the rotating electrical machine to a value that crosses 0 from the rotational speed of the rotating electrical machine. Control device. The battery further comprises power storage means capable of supplying power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine,
In the case where the rotating electrical machine is locked by the locking unit, and the discharge allowable power of the power storage unit is equal to or less than a predetermined value, the control unit does not switch the control of the rotating electrical machine to the fixed magnetic field control, and the rotation The hybrid vehicle control device according to claim 1, wherein rotation of the rotating electrical machine is stopped by magnetic field control. The battery further comprises power storage means capable of supplying power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine,
The control means switches the control of the rotating electrical machine to the fixed magnetic field control when the rotating electrical machine is locked by the locking means and the state quantity corresponding to the power storage state of the power storage means is a predetermined value or less. The hybrid vehicle control device according to claim 1, wherein the rotation of the rotating electrical machine is stopped by the rotating magnetic field control. The battery further comprises power storage means capable of supplying power to the rotating electrical machine and capable of being charged by regenerative power of the rotating electrical machine,
The control means is a case where the rotating electrical machine is locked by the locking means, and when the limit value of the current flowing through the rotating electrical machine is a predetermined value or less, the control of the rotating electrical machine is not switched to the fixed magnetic field control, The hybrid vehicle control device according to claim 1, wherein the rotation of the rotating electrical machine is stopped by the rotating magnetic field control.   6. The control unit according to claim 1, wherein the control unit sets the magnetic field strength of the stator in the fixed magnetic field control to be weaker as a fluctuation range of the torque applied to the rotating shaft before switching to the fixed magnetic field control is smaller. The control apparatus of the hybrid vehicle as described in any one.

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