JP2016124318A - Control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle capable of improving further stability of power generation amount by a power generator.SOLUTION: When a series mode is executed according to a travel state of a vehicle, second torque required for changing a rotational speed of a power generator following up a change in target rotational speed is added to first torque required for setting the rotational speed of the power generator to the target rotational speed so as to calculate target torque. Torque is requested to an engine on the basis of the target torque.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device for a hybrid vehicle including a motor for driving and a generator driven by an engine.

  In recent years, hybrid vehicles in which a driving motor and an engine are combined to obtain a driving force of the vehicle have been developed and put into practical use. As a hybrid vehicle, not only a vehicle (PHV) that charges a battery that drives a generator by an engine to generate electricity and supplies power to a traveling motor but also a battery (PHEV) that can be charged by an external commercial power source is also used. Development and practical use are progressing.

  In such a hybrid vehicle, an EV mode in which driving wheels are driven by using only a traveling motor as a power source, and a generator is driven by an engine while the traveling motor is used as a power source, and electric power is supplied to the battery and the traveling motor. There is a mode in which a series mode to be supplied or a parallel mode in which both an engine and a traveling motor are used as power sources are switched depending on the driving situation (see, for example, Patent Document 1).

JP 2010-083394 A

  By the way, some hybrid vehicles include a feedback control of the rotational speed by the generator, that is, a feedback control so that the rotational speed of the generator becomes a predetermined target rotational speed during the series mode. Thereby, the stability of the amount of power generated by the generator and the rotational speed can be improved.

  However, the stability of the amount of power generated by the generator cannot be said to be sufficient simply by feedback control of the rotational speed of the generator. For example, when the rotational speed of the generator is greatly changed in accordance with the change in the target rotational speed, a desired power generation amount may not be obtained.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a control device for a hybrid vehicle that can further improve the stability of the amount of power generated by a generator.

  A first aspect of the present invention that solves the above problems includes a traveling motor, a battery that supplies electric power to the traveling motor, and a generator that is driven by an engine and generates at least electric power to be supplied to the battery. A hybrid vehicle control device having a travel mode control means for executing a series mode in which power is generated by the generator while traveling by the driving force of the travel motor according to a travel state of the hybrid vehicle; Calculation means for calculating a target rotational speed and target torque of the generator based on a required power generation amount required for the generator during the series mode; engine control means for controlling the engine based on the target torque; The calculation means has a first torque required to set the rotational speed of the generator to the target rotational speed, and Lying in the control apparatus for a hybrid vehicle according to claim that following the change in the target rotational speed by adding the second torque required to change the rotational speed of the generator calculates the target torque.

  According to a second aspect of the present invention, in the hybrid vehicle control device according to the first aspect, the calculation means calculates a change rate of the target rotation speed at a predetermined interval, and the change rate of the target rotation speed and the power generation The second torque is calculated based on the machine and the inertia of the engine.

  According to a third aspect of the present invention, in the hybrid vehicle control device according to the first or second aspect, the calculation means adds the second torque when the target rotational speed is increasing. In a control device for a hybrid vehicle.

  In the hybrid vehicle control apparatus of the present invention, the stability of the amount of power generated by the generator can be further improved. For example, even when the target rotational speed of the generator increases with a decrease in the state of charge (SOC) of the battery, a desired power generation amount can be stably obtained.

It is the schematic which shows an example of the hybrid vehicle which concerns on this invention. 1 is a block diagram illustrating a control device for a hybrid vehicle according to an embodiment of the present invention. It is a figure explaining the calculation method of the required electric power generation in the control apparatus of the hybrid vehicle which concerns on one Embodiment of this invention. It is a graph which shows an example of a change in rotation speed and torque of a generator.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, an example of the configuration of the hybrid vehicle according to the present embodiment will be described.
As shown in FIG. 1, a hybrid vehicle (hereinafter also simply referred to as “vehicle”) 10 according to the present embodiment includes a front motor 11, a rear motor 12, and an engine 13 as a driving source for traveling. The driving force of the front motor 11 is transmitted to the front wheels 15 via the front drive transmission mechanism 14. The driving force of the rear motor 12 is transmitted to the rear wheel 17 via the rear drive transmission mechanism 16. A battery 19 is connected to the front motor 11 via a front (Fr) motor inverter 18, and a battery 19 is connected to the rear motor 12 via a rear (Re) motor inverter 20. Electric power corresponding to the passenger's pedal operation is supplied from the battery 19 to the motors 11 and 12 via the inverters 18 and 20.

  The engine 13 is driven by burning the fuel supplied from the fuel tank 24. A generator (generator) 26 is connected to the engine 13 via an output system 25. The generator 26 is connected to the battery 19 (and the front motor 11) via a generator inverter 27. The output system 25 is connected to the generator 26, and is also connected to the front drive transmission mechanism 14 via the clutch 28.

  When the engine 13 is driven according to the driving state of the vehicle 10, the driving force of the engine 13 is first transmitted to the generator 26 via the output system 25. The generator 26 is rotated by the driving force of the engine 13, and the electric power generated by the generator 26 is appropriately supplied to the battery 19 and the front motor 11 as necessary. When the output system 25 and the front drive transmission mechanism 14 are connected by the clutch 28 according to the driving state of the vehicle 10, the driving force of the engine 13 is transmitted to the generator 26 and also to the front wheels 15.

  Thus, in the vehicle 10 according to the present embodiment, the EV mode using the front motor 11 and the rear motor 12 as power sources for vehicle travel, and the power for vehicle travel according to the driving state of the vehicle 10. A series mode in which the engine 13 is used as a power source for the generator 26 and a parallel mode in which each of the front motor 11, the rear motor 12, and the engine 13 is a power source for vehicle travel are appropriately selected. It has become.

  Further, the vehicle 10 is provided with a control device 30 that comprehensively controls various devices mounted on the vehicle 10. The control device 30 grasps the driving state of the vehicle 10 based on signals from various sensors provided in the vehicle 10, and comprehensively controls various devices based on the grasped state.

  As described below, the present invention is characterized by the power generation amount control of the generator 26 in the series mode executed by the control device 30.

  As shown in FIG. 2, the control device 30 includes a motor control unit 31 that controls the driving of the front motor 11 and the rear motor 12 and an engine control unit 32 that controls the driving of the engine 13. Mode control means 34 and calculation means 35 are provided.

  The travel mode control unit 34 appropriately switches the above-described three travel modes of the EV mode, the series mode, and the parallel mode based on the driving state of the vehicle 10. Specifically, based on the vehicle speed detected by the vehicle speed sensor 41, the accelerator opening of the vehicle 10 detected by the accelerator position sensor (APS) 42, the state of charge (SOC) of the battery 19 detected by the battery sensor 43, and the like. Thus, the travel mode control means 34 appropriately switches between the three travel modes. In addition, since the switching method of driving modes is an existing technique, detailed description here is abbreviate | omitted.

  The calculating means 35 functions when the traveling mode is switched to the series mode by the traveling mode control means 34, and based on the required power generation amount PW0 required for the generator 26, which is a generator, the target rotational speed Nm0 of the generator 26 and A target torque Tq0 is calculated.

  The required power generation amount PW0 is obtained as follows. As shown in FIG. 3, the power (charging power) supplied to the battery 19 is calculated based on the state of charge (SOC) of the battery 19 detected by the battery sensor 43. When the electric power generated by the generator 26 is supplied to the front motor 11, based on the vehicle speed detected by the vehicle speed sensor 41 and the accelerator opening of the vehicle 10 detected by the accelerator position sensor (APS) 42, Electric power (traveling power) that needs to be supplied to the front motor 11 is calculated. Then, the required power generation amount PW0 is calculated by adding the charging power and the traveling power.

  Then, the calculating means 35 calculates the target rotational speed Nm0 based on the required power generation amount PW0, and calculates the target torque Tq0 from the required power generation amount PW0 and the target rotational speed Nm0. The calculation method of the target rotation speed Nm0 and the target torque Tq0 is not particularly limited, but can be obtained by referring to a predetermined map, for example.

  Here, the target rotational speed Nm0 is calculated at a predetermined calculation interval Tc, and is appropriately changed according to changes in the traveling state of the vehicle 10 and the charging state of the battery 19. For example, in the example shown in FIG. 4A, the target rotational speed Nm0 is set to the first rotational speed Nm1 in the period from time T1 to T2, and the target rotational speed Nm0 in the period from time T3 to T4 is the first. Is set to a second rotation speed Nm2 that is greater than the rotation speed Nm1. In the period from time T2 to T3, the target rotational speed Nm0 is set to gradually increase (change) from the first rotational speed Nm1 to the second rotational speed Nm2.

  The target torque Tq0 is also appropriately changed according to the change in the target rotational speed Nm0. For example, in the example shown in FIG. 4B, the target torque Tq0 is set to the first target torque Tq01 in the period from time T1 to T2, and the target torque Tq0 in the period from time T3 to T4 is the first target torque. The second target torque Tq02 is set to be larger than the torque Tq01. In the period from time T2 to T3, the target torque Tq0 is set to gradually increase (change) from the first target torque Tq01 to the second target torque Tq02.

  Then, the engine control unit 32 controls the engine 13 based on the calculation result of the calculation unit 35 such that the output torque Tq of the generator 26 becomes the target torque Tq0.

  On the other hand, as shown in FIG. 4B, the output torque Tq actually output from the generator 26 is equal to the target torque Tq0 during the periods T1-T2 and T3-T4 where the target torque Tq0 is substantially constant. It is controlled to become. However, in the period T2-T3 in which the target torque Tq0 changes (increases), the output torque Tq of the generator 26 has a low value that deviates from the target torque Tq0. This is considered to be caused by changing the rotational speed of the generator 26 in the period T2-T3 shown in FIG.

  Thus, if the output torque Tq deviates from the target torque Tq0, the required power generation amount PW0 cannot be obtained, and the battery 19 may not be charged properly. Further, when electric power is supplied from the generator 26 to the front motor 11, the vehicle 10 may not be accelerated sufficiently.

Therefore, in the present invention, the calculation means 35 calculates the target torque Tq0 as follows. Specifically, the calculating unit 35 follows the change in the target rotational speed Nm0 to the first torque Tqn1 required to set the actual rotational speed Nm of the generator 26 to the target rotational speed Nm0, and the rotational speed Nm of the generator 26. The target torque Tq0 is calculated by adding the second torque Tqn2 necessary for changing the torque. That is, the target torque Tq0 is obtained from the following formula (1).
Tq0 = Tqn1 + Tqn2 (1)

Here, the second torque (inertia torque) Tqn2 is a torque required to rotate the rotor of the generator 26 (and the crankshaft of the engine 13). The second torque Tqn2 is calculated from the inherent inertia (moment of inertia) Ie determined by the structure of the generator 26 (and the engine 13) and the rate of change dNm0 of the target rotational speed Nm0. That is, the second torque Tqn2 is obtained from the following equation (2). In the formula, k is a coefficient.
Tqn2 = Ie × dNm0 × k (2)

The change rate dNm0 of the target rotation speed Nm0 is calculated as follows. The target rotation speed Nm0 is calculated at the predetermined calculation interval Tc as described above, and the rate of change dNm0 is calculated using the target rotation speed Nm0 (n) calculated this time and the target rotation speed Nm0 (n−1) calculated last time. ) And the calculation interval Tc. That is, the change rate dNm0 is obtained from the following equation (3).
dNm0 = (Nm0 (n) −Nm0 (n−1)) / Tc (3)

  By calculating the second torque (inertia torque) Tqn2 in this way, the second torque Tqn2 is calculated only when the target rotational speed Nm0 is changing. For example, in the example shown in FIG. 4B, the target torque Tq0 is obtained by adding the second torque Tqn2 to the first torque Tqn1 during the period from time T2 to T3 when the target torque Tq0 changes. . Thereby, also in the period from time T2 to T3, the output torque Tq of the generator 26 approaches the target torque Tq0.

  On the other hand, in the period T1-T2 and the period T3-T4 in which the target torque Tq0 is a substantially constant value, the change rate dNm0 of the target rotational speed Nm0 is zero, and the second torque Tqn2 is also zero. That is, the target torque Tq0 is the first torque Tqn1. Therefore, the output torque Tq of the generator 26 does not depart from the target torque Tq0 also in the periods T1-T2 and T3-T4.

  As described above, in the present invention, when the series mode is selected as the travel mode of the vehicle 10 and the target rotational speed Nm0 is changing (increasing), the rotational speed Nm of the generator 26 is set to the target rotational speed Nm0. The target torque Tq0 is calculated by adding the second torque Tqn2 necessary for changing the rotational speed of the generator 26 to follow the change in the target rotational speed Nm0. did.

  Thereby, even if it is the period when the target rotational speed Nm0 is changing (increasing), the output torque Tq of the generator 26 can be made into the target torque Tq0. That is, the required power generation amount PW0 can be reliably generated by the generator 26 regardless of the change in the target rotational speed Nm0. Therefore, the battery 19 can be appropriately charged regardless of the traveling state of the vehicle 10, and a desired acceleration feeling can be obtained when electric power is supplied from the generator 26 to the front motor 11.

  In the above-described embodiment, the target torque Tq0 is obtained by adding the second torque Tqn2 to the first torque Tqn1 even during the period in which the target rotation speed Nm0 decreases. However, the difference between the target torque Tq0 and the output torque Tq actually output from the generator 26 is small during the period when the target rotational speed Nm0 decreases. For this reason, it is preferable that the target torque Tq0 be the first torque Tqn1 during the period in which the target rotational speed Nm0 decreases.

  As mentioned above, although one Embodiment of this invention was described, of course, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning, it can change suitably.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Front motor 12 Rear motor 13 Engine 14 Front drive transmission mechanism 15 Front wheel 16 Rear drive transmission mechanism 17 Rear wheel 18 Front motor inverter 19 Battery 20 Rear motor inverter 24 Fuel tank 25 Output system 26 Generator 27 Generator inverter 28 Clutch 30 Control device 31 motor control means 32 engine control means 34 travel mode control means 35 calculation means 41 vehicle speed sensor 42 accelerator position sensor (APS)
43 Battery sensor

Claims (3)

A control device for a hybrid vehicle, comprising: a traveling motor; a battery that supplies electric power to the traveling motor; and a generator that is driven by an engine and generates electric power supplied to at least the battery,
Travel mode control means for executing a series mode in which power is generated by driving the generator by the engine and driving by the engine according to the driving state of the vehicle,
A calculation means for calculating a target rotational speed and a target torque of the generator based on a required power generation amount required for the generator during the series mode;
Engine control means for controlling the engine based on the target torque,
The calculation means is necessary to change the rotation speed of the generator to follow the change in the target rotation speed to the first torque required to set the rotation speed of the generator to the target rotation speed. A control device for a hybrid vehicle, wherein the target torque is calculated by adding a second torque. In the hybrid vehicle control device according to claim 1,
The calculating means calculates a change rate of the target rotation speed at a predetermined interval, and calculates the second torque based on the change rate of the target rotation speed and inertia of the generator and the engine. A control device for a hybrid vehicle. In the control apparatus of the hybrid vehicle according to claim 1 or 2,
The control means for a hybrid vehicle, wherein the calculating means adds the second torque when the target rotational speed is increasing.