JP7181714B2 - Vehicle drive system controller - Google Patents

Description

The present invention relates to a control device applied to a vehicle drive system including a rotating electric machine and an inverter.

2. Description of the Related Art In recent years, in order to extend the cruising range of electric vehicles (EV vehicles) and improve their convenience, technology has been developed to reduce power loss in each component. As a technique for reducing the loss, there is rectangular wave control of the inverter. In the rectangular wave control, the switching loss is reduced by reducing the number of switching times of the inverter as compared with the PWM control. In addition, since the frequency and magnitude of the current ripple originating from the carrier are reduced, iron loss in the rotating electric machine is also reduced. Therefore, extending the period during which the rectangular wave control is performed is one means for extending the cruising distance.

JP 2010-220431 A

For example, Japanese Patent Laid-Open Publication No. 2002-300001 discloses a technique for extending the period of time during which rectangular wave control is performed. This extends the period in which rectangular wave control can be performed by controlling a boost converter (PAM control) that increases the voltage. This reduces switching losses in the inverter. However, there are losses in the boost converter. Also, increasing the voltage increases the loss in the reactor of the boost converter. Especially in the high power range, such an increase in loss becomes remarkable.

In addition, as another technique, there is a technique for expanding the area in which rectangular wave control is performed by performing field-strengthening control. This also reduces switching losses in the inverter. However, since the current effective value increases in the low torque region, there is a demerit that conduction loss in the rotary electric machine and conduction loss in the inverter increase.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce power loss in a vehicle drive system including a rotating electric machine and an inverter.

A control device according to the present invention includes a rotating electrical machine, an inverter for transmitting power between the rotating electrical machine and a DC power supply, a power transmission mechanism for transmitting power of the rotating electrical machine to drive wheels of a vehicle, and the power transmission mechanism. and a transmission provided in a vehicle drive system.

The control device includes an acquisition unit that acquires a first map parameter that is the running speed of the vehicle or a correlation value thereof and a second map parameter that is the driving torque of the drive wheels or the correlation value thereof; Overmodulation control or square wave control of the control mode of the inverter based on a map parameter, the second map parameter, and a map defining predetermined information associated with the first map parameter and the second map parameter. If it is determined that there is a gear ratio of the transmission that can be controlled, the current gear ratio is controlled to become a gear ratio that can be controlled by the overmodulation control or the rectangular wave control, and and a control unit that controls the inverter so that the control mode of is the overmodulation control or the rectangular wave control.

According to the present invention, when there is a gear ratio in which the control mode is overmodulation control or rectangular wave control, the gear ratio is controlled so as to be overmodulation control or rectangular wave control. The control period is extended. Therefore, the switching loss of the inverter is reduced. In addition, since the frequency and magnitude of the current ripple are reduced, iron loss in the rotating electric machine is also reduced. As described above, according to the present invention, it is possible to reduce the loss of the vehicle drive system.

Schematic diagram showing the control device and the like of the first embodiment Flowchart showing shift control by control device A diagram showing a map when the vehicle is accelerated with a constant driving torque command value A diagram showing a map when the vehicle is decelerated with a constant drive torque command value Diagram showing changes in each value when the vehicle is decelerated with a constant drive torque command value A diagram showing a map of the first embodiment and a conventional map Graph showing the effect of the first embodiment Flowchart showing shift control in the second embodiment A diagram showing a map when the vehicle is decelerated with a constant drive torque command value A diagram showing a map of the third embodiment The figure which shows the map of 4th Embodiment Flowchart showing gear shift control in the fifth embodiment A diagram showing a map when the vehicle is accelerated with a constant driving torque command value The figure which shows the map of 6th Embodiment

Next, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments, and can be modified as appropriate without departing from the gist of the invention.

[First embodiment]
As shown in FIG. 1, a control device 91 of the present embodiment is applied to a vehicle drive system 90, such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, which uses a rotating electrical machine as a driving power source for the vehicle. Vehicle drive system 90 includes battery 10 (DC power supply), inverter 20 , rotary electric machine 30 , power transmission mechanism, and drive wheels 50 .

Inverter 20 converts a direct current supplied from battery 10 into an alternating current and transmits the alternating current to rotating electric machine 30 . The rotating electrical machine 30 includes a stator winding and a rotor that is rotationally driven by the stator winding. A rotation speed N (rotation speed N of the rotor) of the rotary electric machine 30 is measured by a rotation speed sensor 32 .

The power transmission mechanism includes a first shaft 39 that rotates together with the rotor of the rotary electric machine 30, a second shaft 41 that rotates together with the driving wheels 50 of the vehicle, and a speed changer provided between the first shaft 39 and the second shaft 41. machine 40; The transmission 40 changes the gear ratio between the first shaft 39 and the second shaft 41 . Specifically, the transmission 40 of the present embodiment is a two-speed automatic transmission, and has a first gear ratio ρL and a second gear ratio ρH (<ρL) lower than the first gear ratio ρL. switch to When the rotational speed of the rotor of the rotary electric machine 30 and the first shaft 39 is N, the rotational speed of the second shaft 41 and the drive wheels 50 is Nt, and the gear ratio of the transmission 40 is ρ, in the present embodiment, " N=ρ×Nt” holds. Therefore, if the rotational speed Nt of the drive wheels 50 is the same, the rotational speed N of the rotor of the rotary electric machine 30 when the gear ratio ρ is set to the first gear ratio ρL is the gear ratio ρ to the second gear ratio ρH is higher than the rotational speed N of the rotor when . Also, in the present embodiment, the first and second gear ratios ρL and ρH are set to values greater than one. That is, the transmission 40 reduces the rotation speed N of the rotor and transmits it to the driving wheels 50 . The second gear ratio ρH is comparable to the gear ratio of a conventional constant gear ratio vehicle drive system, and the first gear ratio ρL is higher than the gear ratio of a conventional constant gear ratio vehicle drive system.

Next, the control device 91 will be explained. The control device 91 includes a driving force calculation section 15 , an inverter control section 25 and a transmission control section 45 . The driving force calculator 15 calculates a driving torque command value T for the drive wheels 50 from the opening degree of the accelerator 14 .

The inverter control unit 25 acquires the driving torque command value T from the driving force calculation unit 15, acquires the rotation speed N of the rotary electric machine 30 from the rotation speed sensor 32, and controls the inverter 20 based on these values. The inverter control unit 25 selects and executes PWM control (pulse width modulation control), overmodulation control, or rectangular wave control. Note that, in the present embodiment, maximum torque control is performed regardless of which of the above controls is selected. Maximum torque control is control that adjusts the current phase so that the output torque of the rotary electric machine is maximized with respect to the same current.

When the peak value of each phase voltage applied to the stator windings of rotating electric machine 30 is equal to or lower than the output voltage of battery 10, PWM control is performed so that each phase voltage applied to the stator windings has a PWM voltage waveform. This control drives the upper and lower arm switches of the inverter 20 by sine wave PWM control.

Overmodulation control is performed so that when the peak value of each phase voltage applied to the stator windings exceeds the output voltage of battery 10, the PWM voltage waveform has a higher voltage utilization factor m than the PWM waveform voltage obtained by PWM control. , and lower arm switches.

Rectangular wave control is control in which the upper and lower arm switches are turned on once each in one electrical angle cycle of the rotary electric machine 30 .

The transmission control unit 45 includes an acquisition unit 46 , a determination unit 47 and a gear ratio control unit 48 . The acquisition unit 46 acquires the vehicle speed V (vehicle running speed) from the vehicle speed sensor 52 and acquires the drive torque command value T from the drive force calculation unit 15 .

The determining unit 47 has a map M for obtaining the voltage utilization rate m from the vehicle speed V and the driving torque command value T. FIG. The voltage utilization factor m is represented by the following formula (eq1). Here, Vd is the d-axis voltage, Vq is the q-axis voltage, and Vdc is the voltage of the battery 10 . Note that the map M is stored in a storage unit such as a memory included in the control device 91, for example.

In this embodiment, the map M is information in which the voltage utilization rate m is defined in association with the vehicle speed V and the driving torque command value T, as shown in FIG. In FIG. 3, the horizontal axis is the vehicle speed V, the vertical axis is the drive torque command value T, and the axis perpendicular to the paper surface is the voltage utilization rate m. The map M is deformed by changing the aspect ratio when the gear ratio of the transmission 40 is changed. Specifically, when the gear ratio is shifted up from the first gear ratio ρL to the second gear ratio ρH, the gear is longitudinally compressed by ρH/ρL and laterally expanded by ρL/ρH. On the other hand, when downshifting from the second gear ratio ρH to the first gear ratio ρL, the gear is longitudinally expanded by ρL/ρH times and laterally compressed by ρH/ρL times.

Hereinafter, the map M at the first gear ratio ρL will be referred to as "first map M1", and the map M at the second gear ratio ρH will be referred to as "second map M2". The solid line in FIG. 3(a) and the broken line in FIG. 3(b) indicate the first map M1, and the solid line in FIG. 3(b) and the broken line in FIG. 3(a) indicate the second map M2. Within each map M1, M2, there is a PWM control area Ma, an overmodulation control area Mb, and a square wave control area Mc. When the operating point P (V, T) obtained from the vehicle speed V and the driving torque command value T exists within the PWM control area Ma, the voltage utilization factor m becomes a value less than the first specified value, and the control mode is PWM control is chosen. In this embodiment, the first specified value is 0.613. Further, when the operating point P (V, T) exists within the overmodulation control region Mb, the voltage utilization factor m becomes a value equal to or greater than the first specified value and less than the second specified value, and the overmodulation control is set as the control mode. To be elected. In this embodiment, the second specified value is 0.78. Further, when the operating point P(V, T) exists within the rectangular wave control region Mc, the voltage utilization factor m becomes the second specified value and the rectangular wave control is selected as the control mode.

Specifically, the determination unit 47 includes a utilization rate calculation unit 47a and a mode determination unit 47b. The utilization factor calculator 47a calculates the voltage utilization factor m based on the vehicle speed V, the drive torque command value T, and the map M. The mode determining unit 47b selects PWM control when the voltage utilization factor m is less than 0.613, and selects overmodulation control when the voltage utilization factor m is greater than or equal to 0.613 and less than 0.78. and square wave control is selected when the voltage utilization factor m is 0.78.

If there is a gear ratio that allows the control mode to be overmodulation control or rectangular wave control, the gear ratio control unit 48 shown in FIG. do.

Next, shift control by the control device 91 of the present invention will be described with reference to FIG.

First, the acquiring unit 46 acquires the driving torque command value T from the driving force calculating unit 15 and acquires the vehicle speed V from the vehicle speed sensor 52 (S101). Next, the utilization factor calculator 47a calculates the voltage utilization factor m from the drive torque command value T and the vehicle speed V that have been acquired, and the map M (S102).

Next, the mode determination unit 47b determines whether or not there is a gear ratio that allows the control mode to be overmodulation control or rectangular wave control (S103). Specifically, when the mode determination unit 47b determines that there is a gear ratio that makes the voltage utilization factor m 0.613 to 0.78, the mode determination unit 47b selects the overmodulation control or the rectangular wave control, so the process proceeds to S104. On the other hand, if it is determined that there is no gear ratio at which the voltage utilization factor m is 0.613 to 0.78 (S103: NO), in S108, the control mode of the inverter 20 is changed to PWM control while maintaining the current gear ratio. and

On the other hand, if there is a gear ratio that satisfies the condition (S103: YES), the gear ratio control unit 48 determines whether or not there are a plurality of gear ratios that satisfy the condition (S104). If there are not a plurality of gear ratios that satisfy the conditions (S104: NO), the gear ratio control unit 48 selects the only gear ratio that satisfies the conditions from among the first and second gear ratios ρL and ρH (S105). On the other hand, if there are multiple gear ratios that satisfy the condition (S104: YES), the gear ratio control unit 48 selects the gear ratio closest to the current gear ratio from among the first and second gear ratios ρL and ρH ( S106).

Next, in S107, the transmission control unit 45 controls the transmission 40 so as to achieve the gear ratio selected in S105 or S106, and the inverter control unit 25 sets the current control mode to S105 or S106. The inverter 20 is controlled so as to be in the control mode corresponding to the gear ratio selected in . At this time, the inverter control unit 25 controls the inverter 20 so as to suppress the driving torque applied from the rotary electric machine 30 to the driving wheels 50 from changing before and after the gear ratio is changed. Specifically, when shifting up from the first gear ratio ρL to the second gear ratio ρH, the rotation speed N of the rotating electric machine 30 is reduced by ρH/ρL, and the driving torque of the rotating electric machine 30 is reduced. The inverter 20 is controlled so as to increase ρL/ρH times. Further, when shifting down from the second gear ratio ρH to the first gear ratio ρL, the rotation speed N of the rotating electric machine 30 is increased by ρL/ρH times, and the drive torque of the rotating electric machine 30 is increased by ρH/ρL times. Inverter 20 is controlled so as to decrease as much as possible. As a result, the driving torque is substantially the same before and after the gear ratio is changed.

Next, as a specific example, a case in which the vehicle is accelerated while the drive torque command value T is kept constant will be described with reference to FIGS. In the initial state of V=0, the first gear ratio ρL is selected as the gear ratio of the transmission 40 . Even if the vehicle accelerates from that state, as shown in FIG. During the period t1 within the region M1a, the first gear ratio ρL continues to be selected. This is because it is determined in S103 that there is no gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: NO), and the process of S108 is executed.

After that, the first gear ratio ρL is maintained during a period t2 from when the operating point P enters the overmodulation control region M1b of the first map M1 to before it enters the overmodulation control region M2b of the second map M2. . This is because it is determined in S103 that there is a gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: YES), and it is determined in S104 that there are not a plurality of such gear ratios (S104: NO). , S106, the first gear ratio ρL, which is the current gear ratio, is selected as the only gear ratio.

Thereafter, the first gear ratio ρL is maintained during a period t3 from when the operating point P enters the overmodulation control region M2b of the second map M2 to when it exits the rectangular wave control region M1c of the first map M1. This is because it is determined in S103 that there is a gear ratio that satisfies the voltage utilization factor m of 0.613 to 0.78 (S103: YES), and in S104 it is determined that there are a plurality of gear ratios (S104: YES). , S106, the first gear ratio ρL, which is the current gear ratio, is selected as the gear ratio closest to the current gear ratio.

After that, as shown in FIG. 3(b), when the operating point P exits the rectangular wave control region M1c of the first map M1 (when the period t4 is entered), the gear ratio of the transmission 40 is changed to the second gear. Shift up to the ratio ρH. This is because it is determined in S103 that there is a gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: YES), and it is determined in S104 that there are not a plurality of such gear ratios (S104: NO). , S105, the second gear ratio ρH is selected as the only gear ratio. During this shift-up, the inverter control unit 25 reduces the rotation speed N of the rotating electric machine 30 by ρH/ρL times, and operates the inverter 20 so as to increase the drive torque of the rotating electric machine 30 by ρL/ρH times. Control.

Next, the case where the vehicle is decelerated while keeping the driving torque command value T constant will be described with reference to FIGS. 2 and 4. FIG. As shown in FIG. 4A, the operating point P is within the overmodulation control region M2b or the rectangular wave control region M2c of the second map M2 and outside the rectangular wave control region M1c of the first map M1. During the period t4', the second gear ratio ρH continues to be selected as in the period t4 described above.

Thereafter, the second gear ratio ρH continues to be selected during t3' from when the operating point P enters the rectangular wave control region M1c of the first map M1 until it exits the overmodulation control region M2b of the second map M2. This is because it is determined in S103 that there is a gear ratio that satisfies the voltage utilization factor m of 0.613 to 0.78 (S103: YES), and in S104 it is determined that there are a plurality of gear ratios (S104: YES). , S106, the second gear ratio ρH, which is the current gear ratio, is selected as the gear ratio closest to the current gear ratio.

When the operating point P enters the PWM control region M2a of the second map M2 (at t2), the gear shifts down to the first gear ratio ρL. This is because it is determined in S103 that there is a gear ratio that satisfies the condition that the voltage utilization factor m is 0.613 to 0.78 (S103: YES), and in S104 it is determined that there are not a plurality of gear ratios (S104: NO). , S105, the first gear ratio ρL is selected as the only gear ratio. During this shift down, the inverter control unit 25 controls the inverter 20 so as to increase the rotational speed N of the rotary electric machine 30 by ρL/ρH and decrease the drive torque by ρH/ρL. During the subsequent periods t2' and t1', the first gear ratio ρL continues to be selected as in the case of t2 or t1, even if the speed is decelerated.

In this manner, during acceleration, the upshift occurs between t3 and t4 shown in FIG. 3, and during deceleration, the downshift occurs between t3' and t2' shown in FIG. Even when the vehicle speed V comes and goes between t3' and t2', upshifting and downshifting are not continuously repeated.

FIG. 5 is a graph showing changes in each value when decelerating while keeping the driving torque command value T constant as shown in FIG. Specifically, FIG. 5A is a graph showing the relationship between vehicle speed V and elapsed time. FIG. 5(b) is a graph showing the relationship between the drive torque applied to the drive wheels 50 and the elapsed time. FIG. 5(c) is a graph showing the relationship between the voltage utilization rate m and elapsed time. FIG. 5(d) is a graph showing the relationship between the gear ratio ρ and the elapsed time. FIG. 5(e) is a graph showing the relationship between the rotational speed N of the rotary electric machine 30 and the elapsed time. FIG. 5(f) is a graph showing the relationship between the torque of the rotary electric machine 30 and the elapsed time.

According to the present embodiment, in the second map M2 shown in FIG. In the map M1, an overmodulation control region Mb (M1b) and a rectangular wave control region Mc (M1c) are formed on the lower speed side than in the conventional case where the gear ratio is constant. Therefore, when the second map M2 and the first map M1 are included, the overmodulation control regions M1b, M2b and the rectangular wave control regions M1c, M2c are enlarged. As a result, overmodulation control or rectangular wave control is performed even during periods (t2, t2', etc.) in which PWM control is performed conventionally. Therefore, during that period (t2, t2', etc.), the number of times of switching is reduced compared to the conventional case, and the switching loss of the inverter 20 is reduced. Also, during the above periods (t2, t2', etc.), the frequency and magnitude of the current ripple are smaller than in the conventional case, so the iron loss in the rotary electric machine 30 is also reduced. As described above, according to the present embodiment, it is possible to reduce the loss of the vehicle drive system.

FIG. 6 shows a second map M2 of this embodiment and a conventional map M'. In this embodiment, the second gear ratio ρH is about the same as the conventional gear ratio, and the first gear ratio ρL is used at low speeds to use the first map M1. The maximum torque can be reduced by the ratio of ρL, that is, the maximum torque can be reduced to ρH/ρL times. Therefore, the stacking thickness (the axial length of the rotating electric machine 30) can be reduced to ρH/ρL times the conventional one, and the size and cost of the rotating electric machine 30 can be reduced. Moreover, if the physical size remains the same, the magnetic flux can be reduced by ρH/ρL, that is, a magnet with less surface magnetic flux can be used, so the cost of the rotating electric machine 30 can be reduced.

FIG. 7 is a graph showing the effects of this embodiment. In this embodiment, by providing the transmission 40, a loss occurs in the transmission 40, which is not conventional. loss) is reduced, the overall loss is reduced.

[Second embodiment]
Next, a second embodiment of the invention will be described. In the second embodiment, members, steps, etc. that are the same as or corresponding to those in the first embodiment are denoted by the same reference numerals, and only points that differ from the first embodiment will be described.

In the second embodiment, as shown in FIG. 8, instead of selecting the gear ratio closest to the current gear ratio in S106, the gear ratio with the highest voltage utilization factor m is selected.

As a specific example, a case where the vehicle is decelerated while the drive torque command value T is kept constant will be described with reference to FIGS. 8 and 9. FIG. While the point P is within the overmodulation control region M2b or the rectangular wave control region M2c of the second map M2 and outside the rectangular wave control region M1c of the first map M1, t4' is the same as in the first embodiment. , the second gear ratio ρH is selected.

After that, when the point P enters the rectangular wave control region M1c of the first map M1 (at the time of entering the period t3'), the gear shifts down to the first gear ratio ρL. This is because it is determined in S103 that there is a gear ratio that satisfies the voltage utilization factor m of 0.613 to 0.78 (S106: YES), and in S104 it is determined that there are a plurality of gear ratios (S104: YES). , S106, the first gear ratio ρL is selected as the gear ratio with the highest voltage utilization rate m. After that, the first gear ratio ρL continues to be selected. Note that the upshift timing is the same as in the first embodiment.

According to this embodiment, it is possible to further reduce the power loss by selecting the gear ratio that maximizes the voltage utilization factor m in S103.

[Third embodiment]
Next, a third embodiment of the invention will be described with reference to FIG. In this embodiment, members that are the same as or correspond to those of the first embodiment are denoted by the same reference numerals, and only points that differ from the first embodiment will be described. The transmission 40 is a multi-stage transmission that switches gear ratios in three stages. Therefore, in addition to the first and second maps M1 and M2 corresponding to the first and second gear ratios ρL and ρH, there is a third map M3 corresponding to the third gear ratio. According to this embodiment, it is possible to further extend the period during which overmodulation control or rectangular wave control is performed. In this embodiment, the gear ratio is switched in three steps, but of course, it may be switched in four or more steps.

[Fourth embodiment]
Next, a fourth embodiment of the invention will be described with reference to FIG. In the fourth embodiment, members that are the same as or correspond to those of the first embodiment are denoted by the same reference numerals, and only points that differ from the first embodiment will be described. The transmission 40 is a continuously variable transmission that continuously switches gear ratios. Therefore, the map M has its aspect ratio changed continuously. In this embodiment, the same control as in the first embodiment is performed using the map M in each state in which the gear ratio is changed at predetermined intervals. According to the present embodiment as well, the period during which overmodulation control or rectangular wave control is performed can be extended, as in the third embodiment.

[Fifth embodiment]
Next, a fifth embodiment of the present invention will be described. In this embodiment, members, steps, and the like that are the same as or corresponding to those of the first embodiment are denoted by the same reference numerals, and only points that differ from the first embodiment will be described.

In this embodiment, as shown in FIG. 12, the acquiring unit 46 acquires the torque command value Tm of the rotating electrical machine 30 and the rotation speed N of the rotating electrical machine 30 in S101. Further, as shown in FIG. 13, the map M is different in that it is information in which the voltage utilization rate m is defined in association with the rotation speed N of the rotary electric machine 30 and the torque command value Tm. Specifically, in the map M, the horizontal axis is the rotation speed N of the rotating electrical machine 30 and the vertical axis is the torque command value Tm of the rotating electrical machine 30 . In this embodiment, the map M does not change even if the gear ratio changes.

The operating points are different in that there are a first operating point P1 and a second operating point P2. Specifically, the first operating point P1 indicates the rotation speed N and the torque command value Tm of the rotary electric machine 30 when the first gear ratio ρL is set. Also, the second operating point P2 indicates the rotation speed N and the torque command value Tm of the rotary electric machine 30 when the second gear ratio ρH is set. When the coordinates of the first operating point P1 in the map M are (N1, Tm1) and the coordinates of the second operating point P2 in the map M are (N2, Tm2), N2/N1=ρH/ρL, Tm2/Tm1=ρL/ρH. When shifting up from the first gear ratio ρ1 to the second gear ratio ρ2, the inverter control unit 25 controls the inverter 20 so that the rotation speed N of the rotary electric machine 30 is reduced by ρH/ρL times. Together with this, the torque command value Tm of the rotary electric machine 30 is increased by ρL/ρH times.

Next, as a specific example, a case where the vehicle is accelerated while keeping the drive torque constant will be described with reference to FIGS. 12 and 13. FIG. In FIG. 13(a), the trajectory of the first operating point P1 when the first speed ratio ρ1 is selected is indicated by a solid arrow, and the trajectory of the second operating point P2 in the same state is indicated by a broken arrow. is shown. In FIG. 13(b), the trajectory of the first operating point P1 in the state where the second gear ratio ρ2 is selected is indicated by a dashed arrow, and the trajectory of the second operating point P2 in the same state is indicated by a solid arrow. is shown.

In the initial state of V=0, the first gear ratio ρL is selected as the gear ratio of the transmission 40 . Even if the vehicle accelerates from that state, the first speed ratio ρL continues to be selected during the period t1 when the first operating point P1 is within the PWM control region Ma, as shown in FIG. 13(a). This is because it is determined in S103 that there is no gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: NO), and the process of S108 is executed.

Thereafter, the first gear ratio ρL is maintained during a period t2 from when the first operating point P1 enters the overmodulation control region Mb until before the second operating point P2 enters the overmodulation control region Mb. This is because it is determined in S103 that there is a gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: YES), and it is determined in S104 that there are not a plurality of such gear ratios (S104: NO). , S106, the first gear ratio ρL, which is the current gear ratio, is selected as the only gear ratio.

Thereafter, the first gear ratio ρL is maintained during a period t3 from when the second operating point P2 enters the overmodulation control region Mb to when the first operating point P1 exits the rectangular wave control region Mc. This is because it is determined in S103 that there is a gear ratio that satisfies the voltage utilization factor m of 0.613 to 0.78 (S103: YES), and in S104 it is determined that there are a plurality of gear ratios (S104: YES). , S106, the first gear ratio ρL, which is the current gear ratio, is selected as the gear ratio closest to the current gear ratio.

After that, as shown in FIG. 13(b), when the first operating point P exits the rectangular wave control region Mc (when the period t4 begins), the gear ratio of the transmission 40 changes to the second gear ratio ρH. shift up. This is because it is determined in S103 that there is a gear ratio that satisfies the condition that the voltage utilization rate m is 0.613 to 0.78 (S103: YES), and it is determined in S104 that there are not a plurality of such gear ratios (S104: NO). , S105, the second gear ratio ρH is selected as the only gear ratio.

During this shift up, inverter control unit 25 controls inverter 20 so as to reduce rotational speed N of rotating electrical machine 30 to ρH/ρL times, thereby reducing rotational speed N of rotating electrical machine 30 to the first The rotation speed at the operating point P1 is decreased to the rotation speed at the second operating point P2. Further, inverter control unit 25 increases torque command value Tm for rotary electric machine 30 by ρL/ρH times, thereby increasing torque command value Tm for rotary electric machine 30 from the torque command value at first operating point P1 to the torque command value at the second operation point P1. Increase to the torque command value at point P2.

According to this embodiment, the present invention can be implemented with one map M without deforming the map M. FIG.

[Sixth embodiment]
Next, a sixth embodiment of the present invention will be described. In this embodiment, members, steps, and the like that are the same as or corresponding to those of the first embodiment are denoted by the same reference numerals, and only points that differ from the first embodiment will be described.

FIG. 14 shows the map M of this embodiment. In this embodiment, when the rectangular wave control is performed, the control can be performed up to a higher rotation range, that is, in the map M, the rectangular wave control region Mc extends to a range in which the vehicle speed V becomes higher. Then, field-weakening control is performed. Field weakening control is control that adjusts the current phase so as to weaken the field magnetic flux of the rotating electrical machine 30 compared to maximum torque control. In the field weakening control, a current is passed through the d-axis in order to weaken the back electromotive force of the rotating electric machine 30 . Therefore, more current is consumed than in maximum torque control, and torque output is reduced. Therefore, the upper limit of the drive torque command value T that can be realized also becomes small. As a result, the maximum torque line Tmax in the rectangular wave control region Mc becomes smaller as the vehicle speed V becomes higher than in the first embodiment. Therefore, a region that is not included in the first map M1 but included only in the second map M2 is located on the side where the driving torque command value T is higher than the end of the first map M1 where the vehicle speed V is the highest. R is formed. When the operating point P is within the region R, only the second gear ratio ρ2 can be selected as the gear ratio ρ.

Therefore, for example, in a state in which the operating point P is within the rectangular wave control region M1c of the first map M1 and the first gear ratio ρ1 is selected as the gear ratio ρ, the driving torque command value T increases to When the point P moves into the region R, the gear ratio ρ switches from the first gear ratio ρ1 to the second gear ratio ρ2. This is because in S103 shown in FIG. 2, it is determined that there is a gear ratio that satisfies the condition that the voltage utilization factor m is 0.613 to 0.78 (S103: YES), and in S104 there is not a plurality of gear ratios (S104: NO). ), and the second gear ratio ρH is selected as the only gear ratio in S105. Further, according to the same flow, when the operating point P is maintained within the region R in a state where the second gear ratio ρ2 is selected as the gear ratio ρ, the second gear ratio ρ2 is set as the gear ratio ρ. continue to be selected.

According to the present embodiment, the field-weakening control is performed to widen the rectangular wave control region Mc to a range in which the vehicle speed V becomes higher. In this embodiment, field-weakening control is performed only when rectangular wave control is performed, but field-weakening control may also be performed when overmodulation control is performed.

[Other embodiments]
For example, this embodiment can be implemented with the following modifications. Instead of the vehicle speed V, the horizontal axis of the map M can be represented by its correlation value. As this correlation value, for example, the rotational speed of the driving wheels 50 can be used. Also, the vertical axis of the map M can be replaced with the drive torque command value T and its correlation value. As this correlation value, for example, the driving force of the driving wheels 50 can be used.

Further, instead of calculating the voltage utilization rate based on the vehicle speed V, the drive torque command value T, etc., and determining the control mode based on the calculated voltage utilization rate, etc., the vehicle speed V, the drive torque command value T, etc. It is also possible to determine the control mode directly based on Specifically, for example, information that defines each control mode of PWM control, overmodulation control, and rectangular wave control in association with the vehicle speed V and the driving torque command value T is used as the predetermined information. Then, the control mode can be determined based on the predetermined information.

Further, instead of obtaining the voltage utilization rate m based on the map M, it is also possible to obtain other predetermined information. The predetermined information includes, for example, a voltage standard value obtained by normalizing the effective value of the fundamental wave component included in the voltage applied to each phase winding of the rotary electric machine 30 by the voltage of the battery 10 .

DESCRIPTION OF SYMBOLS 10... Battery, 20... Inverter, 25... Inverter control part, 30... Rotary electric machine, 40... Transmission, 46... Acquisition part, 47... Determination part, 48... Gear ratio control part, 50... Drive wheel, 90... Vehicle drive system, 91... control unit, M... map.

Claims (5)

a rotating electrical machine (30), an inverter (20) for transmitting power between the rotating electrical machine and a DC power supply (10), and a power transmission mechanism for transmitting power of the rotating electrical machine to drive wheels (50) of a vehicle. , a transmission (40) provided in the power transmission mechanism, and a control device (91) applied to a vehicle drive system comprising:
an acquisition unit (46) that acquires a first map parameter that is the traveling speed (V) of the vehicle or its correlation value and a second map parameter that is the driving torque (T) of the drive wheels or its correlation value;
a control unit (25, 47, 48);
with
A voltage standard value is a value obtained by normalizing the effective value of the fundamental wave component contained in the applied voltage to the winding of each phase of the rotating electric machine by the voltage of the DC power supply,
The control unit
Based on the obtained first map parameter and second map parameter, and a map (M) defining the voltage standard value in association with the first map parameter and the second map parameter, the inverter Determining whether there is a gear ratio of the transmission that allows the control mode of to be overmodulation control or rectangular wave control,
When it is determined that there is a gear ratio of the transmission that allows the control mode to be the overmodulation control or the rectangular wave control, the current gear ratio is the gear ratio that allows the overmodulation control or the rectangular wave control. and controlling the inverter so that the current control mode is the overmodulation control or the square wave control ,
When it is determined that there is no transmission gear ratio for which the control mode can be the overmodulation control or the rectangular wave control, the transmission is controlled to maintain the current transmission gear ratio, and A controller for controlling the inverter so that the control mode of is PWM control . A setting range is a range that the voltage standard value can take when the control mode is the overmodulation control or the rectangular wave control,
The control unit
calculating the voltage standard value based on the acquired first map parameter and second map parameter , and the map ;
If the calculated voltage standard value is within the set range, it is determined that there is a gear ratio that allows the control mode to be the overmodulation control or the rectangular wave control ,
2. The control device according to claim 1, wherein when the calculated voltage standard value is below the set range, it is determined that there is no gear ratio that allows the control mode to be the overmodulation control or the rectangular wave control. When the control unit determines that there are a plurality of candidates for the gear ratio that can set the control mode to the overmodulation control or the rectangular wave control, the controller selects the current gear ratio from among the plurality of candidates for the gear ratio. selecting a gear ratio closest to the gear ratio, controlling the transmission so that the current gear ratio becomes the selected gear ratio, and the current control mode being one of the overmodulation control and the square wave control. 3. The control device according to claim 1, wherein the inverter is controlled so as to be in a control mode corresponding to the selected gear ratio. a rotating electrical machine (30), an inverter (20) for transmitting power between the rotating electrical machine and a DC power supply (10), and a power transmission mechanism for transmitting power of the rotating electrical machine to drive wheels (50) of a vehicle. , a transmission (40) provided in the power transmission mechanism, and a control device (91) applied to a vehicle drive system comprising:
an acquisition unit (46) that acquires a first map parameter that is the traveling speed (V) of the vehicle or its correlation value and a second map parameter that is the driving torque (T) of the drive wheels or its correlation value;
a control unit (25, 47, 48);
with
A voltage standard value is a value obtained by normalizing the effective value of the fundamental wave component contained in the applied voltage to the winding of each phase of the rotating electric machine by the voltage of the DC power supply,
A setting range is a range that the voltage standard value can take when the control mode of the inverter is overmodulation control or rectangular wave control,
The control unit
Based on the obtained first map parameter and second map parameter, and a map (M) in which the voltage standard value is defined in association with the first map parameter and the second map parameter, the voltage Calculate the standard value,
If the calculated voltage standard value is within the set range, it is determined that there is a gear ratio of the transmission that allows the control mode to be the overmodulation control or the rectangular wave control, and the current gear ratio is The transmission is controlled to achieve a gear ratio that allows the overmodulation control or the rectangular wave control, and the inverter is controlled so that the current control mode is the overmodulation control or the rectangular wave control. ,
When the control unit determines that there are a plurality of gear ratios that allow the control mode to be the overmodulation control or the rectangular wave control, the voltage standard value is the highest among the plurality of gear ratios. selecting a transmission gear ratio, controlling the transmission so that the current transmission gear ratio becomes the selected transmission gear ratio, and the current control mode being the transmission selected from the overmodulation control and the square wave control; A control device for controlling the inverter to be in a control mode corresponding to the ratio. The control device according to any one of claims 1 to 4, wherein the control unit controls the inverter so as to suppress the torque applied to the drive wheels from changing before and after changing the gear ratio. .

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