JP5958633B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device equipped with a drive motor and an inverter.

  An electric vehicle or a hybrid vehicle equipped with an electric motor as a drive source is equipped with an inverter that supplies AC power to the electric motor as a power source of the electric motor. The inverter is electrically connected to the driving battery, converts the DC power stored in the battery into AC power, and supplies the AC power to the electric motor. The inverter includes a plurality of switching elements such as transistors and thyristors that can withstand high voltages and large currents called IGBTs, and AC power is generated by switching control (switching control) of the plurality of elements.

Since the inverter always generates AC power during operation of the electric motor, the built-in switching element generates heat and becomes high temperature. In particular, the larger the motor output, the larger the current flows through the switching element, so that the inverter has a higher temperature.
Therefore, conventionally, the vehicle has been provided with a cooling device for cooling the inverter. For example, in the technique described in Patent Document 1, a cooling water circulation path for cooling the inverter is provided around the inverter as a cooling device. A water pump and a radiator are interposed in the circulation path, and the cooling water cooled by the radiator is circulated by the water pump, thereby preventing overheating of the inverter. As described above, the cooling device is indispensable for protecting the inverter, and in particular, the water pump is very important for always flowing the flow rate of the cooling water necessary for cooling the inverter through the cooling passage. Device.

JP 2009-112136 A

  However, always operating a pump for sending a cooling medium (for example, cooling water or cooling oil) for cooling the inverter to the cooling passage will shorten the pump life, and therefore, ensure the life. From the viewpoint, it is desirable to suppress unnecessary operations as much as possible. On the other hand, if the pump is started again after being stopped, a certain amount of time is required until the flow rate necessary for cooling the inverter can be fed. For this reason, if a large current flows through the inverter in a state where the flow rate is not sufficient, the switching element in the inverter may be burned out due to overheating, and the pump cannot be stopped unnecessarily. As described above, there is a problem that it is difficult to ensure both the life of the pump and the protection of the inverter.

The present invention has been devised in view of such problems, and an object of the present invention is to provide a vehicle control device that can achieve both the life of the pump and the protection of the inverter.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

  (1) A vehicle control device disclosed herein includes an inverter that generates AC power for driving a motor for driving a vehicle mounted on a vehicle, a pump that sends a cooling medium to a cooling passage that cools the inverter, A shift position sensor for detecting a shift position selected by a shift device for switching the operating state of the motor, and a pump control means for starting the pump when the shift position detected by the shift position sensor switches to a travel range. And, when the shift position is switched to the travel range, motor control means for limiting the vehicle output torque of the motor until a predetermined time elapses from the switching time. .

That is, the pump control means stops the pump before the shift position detected by the shift position sensor is switched to the travel range, and starts the operation of the pump with the switch to the travel range. .
The shift device includes a shift lever, a shift button, and the like, and the cooling medium includes cooling water, cooling oil, and the like. Further, the “vehicle output torque” here means the magnitude of torque output by the motor.

(2) It is preferable that the motor control means reduce the limit of the vehicle output torque of the motor as time elapses from the switching time.
(3) In addition, a temperature acquisition unit that acquires the temperature of the inverter is provided, and the motor control unit increases the limit of the vehicle output torque of the motor as the temperature of the inverter acquired by the temperature acquisition unit increases. It is preferable to correct so that it becomes.

  (4) In addition, a rotation speed sensor for detecting the rotation speed of the pump is provided, and the motor control means limits the vehicle output torque of the motor as the rotation speed detected by the rotation speed sensor increases. It is preferable to make corrections so as to be smaller.

  According to the disclosed vehicle control apparatus, since the pump is stopped before the shift position is switched to the travel range, unnecessary operation of the pump can be suppressed as much as possible to ensure the life of the pump. In this case, since the motor does not generate torque, there is no possibility that the inverter will overheat even if the pump is stopped.

  Further, since the pump is started when the shift position is switched to the travel range, the cooling medium can be fed into the cooling passage while the motor is operating, and the inverter can be cooled. However, it takes a certain amount of time for the pump to flow the flow rate (required flow rate) required for cooling the inverter through the cooling passage. Therefore, in this control device, when the shift position is switched to the travel range, the vehicle output torque of the motor is limited until the predetermined time elapses from the time of switching, and this predetermined time is the amount of heat generated by the inverter. Suppress.

  That is, until the shift position is switched to the travel range and the pump can feed the required flow rate, the motor output torque of the motor can be suppressed to prevent overheating of the inverter. . Therefore, according to the present control device, it is possible to achieve both the life of the pump and the protection of the inverter.

1 is a block diagram illustrating a configuration of a vehicle to which a vehicle control device according to an embodiment is applied. It is the figure which modeled the cooling device of the inverter. For explaining the motor control, (a) is a correction rate map representing the correction rate A of the output torque T over time, and (b) is a limit representing the limiting rate R of the output torque T over time. It is a rate filter. It is a flowchart explaining the control content by the vehicle control apparatus which concerns on one Embodiment, (a) is the flow P regarding pump control, (b) is the flow M regarding motor control. It is for demonstrating the other example of motor control, (a) is a map for acquiring the correction rate B according to the inverter temperature H, (b) is the correction rate C according to the pump rotation speed Np. (C) is a map showing the maximum value T _MAX of the motor output torque T over time.

Hereinafter, embodiments will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment.
[1. Device configuration]
The configuration of the vehicle control device according to the present embodiment will be described with reference to FIG. Here, the case where this control apparatus is provided in the electric vehicle is demonstrated.

  As shown in FIG. 1, an electric vehicle (vehicle) 10 includes a driving electric motor (vehicle power motor) 11 (hereinafter referred to as a motor 11), a battery 12 that stores electric power, and an inverter 13 that generates AC power. , A cooling water pump (pump) 14, a shift lever (including a selector; shift device) 15, and an accelerator pedal 16 are provided.

  The motor 11 is, for example, a high-output permanent magnet synchronous motor, and is an electric motor that receives AC power supplied from the inverter 13 and rotates a rotor (rotor) to convert electrical energy into mechanical energy. The motor 11 is mechanically connected to driving wheels (not shown), and the driving force of the motor 11 is transmitted to the driving wheels to cause the vehicle 10 to travel. The rotation speed Nm [rpm] of the motor 11 is proportional to the frequency of the AC power converted by the inverter 13, and the torque T [Nm] of the motor 11 is proportional to the magnitude of the current supplied to the motor 11. Therefore, the rotational speed Nm and the torque T of the motor 11 can be adjusted by controlling the inverter 13.

The battery 12 is, for example, a lithium ion battery or a nickel hydride battery, and is supplied to the motor 11 after the high-voltage direct current is converted into alternating current by the inverter 13.
The inverter 13 is a power conversion device that is electrically connected to the battery 12, converts a direct current supplied from the battery 12 into a three-phase alternating current, and supplies the three-phase alternating current to the motor 11. The inverter 13 includes a plurality of (for example, three) switching elements, and generates a three-phase alternating current by switching the plurality of elements based on a command from a motor control unit 4 described later. . In addition, the frequency of the alternating current can be changed by changing the switching cycle for switching these switching elements (the time during which current flows through each switching element).

  The switching element is, for example, an IGBT (Insulated Gate Bipolar Transistor), a thyristor, or the like. Here, an IGBT more suitable for high withstand voltage and large current is used. The IGBT is controlled to be switched whenever the motor 11 is operating to generate AC power. At this time, since a relatively large current flows through the IGBT, the IGBT generates heat and becomes high temperature. In particular, when a large current flows through the IGBT, the amount of heat generation is the largest, and thus the temperature H of the inverter 13 also becomes high. In order to cool this, a cooling device is provided around the inverter 13.

  The cooling device includes a water pump 14, a cooling passage 17, and a radiator 18. The water pump 14 is an electric pump (electric pressure feeding device) that circulates (feeds) a cooling medium (for example, cooling water) through the cooling passage 17 (see FIG. 2), and operates with electric power supplied from the battery 12. Although an example in which cooling water is used as the cooling medium will be described here, cooling oil may be used as the cooling medium.

  As shown in FIG. 2, a cooling passage 17 is provided around the inverter 13, and the cooling medium flows through the cooling passage 17 to absorb heat of the inverter 13, thereby cooling the inverter 13. The cooling passage 17 is a circulation circuit through which a cooling medium flows in one direction, and a water pump 14 and a radiator 18 are interposed on the cooling passage 17. The radiator 18 is a device for radiating the heat of the cooling medium. Here, the water pump 14 and the cooling passage 17 are configured as a pump and cooling passage dedicated to the inverter 13, but may be used in combination with a configuration for cooling other devices (for example, a battery, a motor, and the like).

The operation / non-operation (stop) of the water pump 14 is controlled by a pump control unit 3 described later. The discharge amount of the water pump 14 (the flow rate of the cooling medium that can be fed into the cooling passage 17) is determined according to the rotational speed. Here, the water pump 14, the operation is started, automatically increases the pump speed Np to the predetermined rotational speed Np _Q can be discharged a predetermined flow rate (flow rate required) Q, was raised to a predetermined rotational speed Np _Q after maintaining a predetermined rotational speed Np _Q. That is, the water pump 14 is only operated / stopped (ON / OFF) by the pump control unit 3. The predetermined flow rate Q is a flow rate of a cooling medium that can sufficiently cool the inverter 13.

  The shift lever 15 is a switching device (shift device) for selecting and switching the traveling state of the vehicle 10 by a driver's operation, and is provided in the vicinity of the driver's seat. Here, the shift lever 15 is configured to be switched to each range of parking (P range), neutral (N range), drive (D range), and reverse (R range). The driver selects the traveling state by switching the shift lever 15. The shift device is not limited to a lever, and may be a button type, for example.

  The shift lever 15 is provided with a shift position sensor 25 that detects the current shift position (operation position) SP selected by the shift lever 15. The shift position sensor 25 outputs a position signal (position information) corresponding to the operation position of the shift lever 15, for example. Position information detected by the shift position sensor 25 is transmitted to a vehicle ECU 1 described later as needed.

  That is, the switching operation of the shift lever 15 and the operation of the motor 11 are interlocked. For example, when the shift lever 15 is switched to the P range or the N range, the motor 11 is stopped and enters a no-load state. Further, when the shift lever 15 is switched to the D range or the R range, the motor 11 is operated. Hereinafter, ranges other than the P range and the N range (here, the D range and the R range) are referred to as “traveling ranges”. That is, the traveling range means a state in which the motor 11 is working (a load is applied to the motor 11).

An accelerator opening sensor (APS) 26 that detects the opening θ of the accelerator pedal 16 is provided in the vicinity of the accelerator pedal 16. The accelerator opening sensor 26 outputs, for example, an opening signal (opening information) corresponding to the amount of depression of the accelerator pedal 16 by the driver. The accelerator opening information detected by the accelerator opening sensor 26 is transmitted to the vehicle ECU 1 as needed.
The vehicle speed sensor 27 provided at an arbitrary position of the vehicle 10 detects the vehicle speed V of the host vehicle, and outputs a vehicle speed signal (vehicle speed information) corresponding to the rotational speed of the drive wheels, for example. Vehicle speed information detected by the vehicle speed sensor 27 is transmitted to the vehicle ECU 1 as needed.

  In addition, the vehicle 10 is provided with an electronic control unit (hereinafter referred to as ECU) that controls these devices. Here, an inverter ECU 2 that controls the inverter 13 and the water pump 14 and a vehicle ECU (EV-ECU) 1 that integrally controls the vehicle 10 are provided. The inverter ECU 2 and the vehicle ECU 1 are computers each composed of a memory (ROM, RAM) and a CPU. In addition to these, the vehicle 10 is provided with various ECUs such as a battery ECU, an air conditioning ECU, and a brake ECU (not shown).

  The vehicle ECU 1 is connected to various ECUs so that information can be transmitted. The vehicle ECU 1 is connected to a shift position sensor 25, an accelerator opening sensor 26, and a vehicle speed sensor 27 on its input side, monitors the intention (request) from the driver, the traveling state of the vehicle, etc., and transmits information to various ECUs. . Further, the inverter ECU 2 has an inverter 13 and a water pump 14 connected to the output side thereof. The present control device is realized mainly by functions provided in the inverter ECU 2.

[2. Control configuration]
The inverter ECU 2 has a functional element as the pump control unit 3 and a functional element as the motor control unit 4 for vehicle power.

  The pump control unit (pump control means) 3 controls the operation / non-operation of the water pump 14 according to the operation state of the motor 11. Specifically, the pump control unit 3 acquires position information detected by the shift position sensor 25 from the vehicle ECU 1, and when the shift position SP is not in the travel range (that is, when the motor 11 is in a no-load state), The water pump 14 is stopped. On the other hand, the pump control unit 3 operates the water pump 14 when the shift position SP is in the travel range (that is, when a load is applied to the motor 11).

  That is, when the motor 11 is stopped based on the position information acquired from the vehicle ECU 1, the pump control unit 3 stops the water pump 14 and suppresses unnecessary operations. On the other hand, when the shift position SP is switched to the travel range and the motor 11 performs work, the water pump 14 is started and the cooling medium is circulated through the cooling passage 17 to cool the inverter 13.

  The motor control unit (motor control means) 4 controls the inverter 13 to control the operation of the motor 11 based on the output request from the driver and the current running state, and serves as a target torque setting unit 4a. And a functional element as the output torque control unit 4b.

The target torque setting unit 4a determines the torque required by the driver from the shift position SP detected by the shift position sensor 25, the accelerator opening θ detected by the accelerator opening sensor 26, and the vehicle speed V detected by the vehicle speed sensor 27 ( Target torque) T _TGT is calculated and set. Specifically, the target torque setting unit 4a first acquires position information from the vehicle ECU 1, and sets the target torque _TTGT to 0 if the shift position SP is in the P range or the N range.

On the other hand, if the shift position SP is the travel range, the target torque setting unit 4a continuously acquires the opening degree information and the vehicle speed information, and sets the target torque T _TGT from the accelerator opening degree θ and the vehicle speed V. The method for setting the target torque T _TGT is arbitrary. For example, the relationship between the accelerator opening θ, the vehicle speed V, and the target torque T _TGT is mapped in advance for each shift position SP (here, for each D range and R range). The target torque T _TGT is set using these maps.

The output torque control unit 4b sets a command torque (torque command value) T _C from the target torque T _TGT set by the target torque setting unit 4a, and causes the motor 11 to output a torque corresponding to the command torque T _C. The inverter 13 is controlled. Output torque control section 4b, and a filter set the command torque T _C to the target torque T _TGT using a map shown in FIG. 3 (a). FIG. 3A is a correction rate map showing the correction rate A of the output torque (vehicle output torque) T with respect to the elapsed time from time t ₀ . Here, “output torque T” means torque that is actually output by the motor 11 and may be regarded as the same as the instruction torque T _C set by the output torque control unit 4b.

The output torque control unit 4b sets a value obtained by multiplying the target torque T _TGT set by the target torque setting unit 4a by the correction factor A (0 <A ≦ 1) as the instruction torque T _C (that is, T _C = A × T _TGT ). That is, this correction factor A is a correction coefficient used to determine the output torque T that is actually output to the motor 11. As shown in FIG. 3A, the correction factor A is set to the initial correction factor A ₀ (A ₀ <1) at time t _{0 and} is set to gradually (smoothly) increase with time. Has been. The correction rate A is set to 1 at time t ₁ , and the correction rate A is always set to ₁ after time t ₁ .

Here, time t ₀ is “when switching” when the shift position SP is switched from the P range or the N range to the travel range. Time t ₁ is the time when the rotation speed Np of the water pump 14 reaches the predetermined rotation speed Np _Q. Further, the time from the switching time t ₀ to the time t ₁ is the time required for the pump rotational speed Np to rise to the predetermined rotational speed Np ₀ from the start of the operation of the water pump 14, and this is the predetermined time Z (Z = t ₁ −t ₀ ). Here, the water pump 14 is because it is intended to be performed only on-off control, the predetermined time Z required to rise to the predetermined rotational speed Np _Q, it is previously predetermined value set.

That is, when the shift position SP is switched from the P range or the N range to the travel range, the output torque control unit 4b sets the target torque T _TGT to 1 for the predetermined time Z from the switching time t _0. set the command torque T _C is multiplied by a small correction rate a than. In other words, the output torque control unit 4b limits the output torque T of the motor 11 by setting the instruction torque T _C smaller than the target torque T _TG during the predetermined time Z. Since the correction rate A is gradually increased from the switching time t ₀ , the limit of the output torque T with respect to the target torque T _TGT gradually decreases.

The reason why the output torque control unit 4b limits the output torque T of the motor 11 during the predetermined time Z will be described. When the shift position SP is in the P range or the N range, the pump control unit 3 stops the water pump 14, and starts the operation of the water pump 14 when the shift position SP is switched to the travel range. However, the pump speed Np of the water pump 14, to rise up to a predetermined rotational speed Np _Q for gradually increases from the start operation (start-up) requires a predetermined time Z.

That is, during the predetermined time Z, the cooling of the inverter 13 by the water pump 14 may be insufficient. For example, if a request for maximizing the output torque T of the motor 11 is input from the driver during the predetermined time Z, the inverter 13 needs to flow a large current to the motor 11 and overheats (overheats). There is a risk that. Therefore, the output torque control section 4b, the pump speed Np of water pump 14 during a predetermined time Z until the rise to a predetermined rotational speed Np _Q, to limit the output torque T of the motor 11 to protect the inverter 13 .

If the correction rate A is expressed in another way, it can also be expressed as the limiting rate R of the output torque T of the motor 11. FIG. 3B is a limiting rate filter showing the limiting rate R of the output torque T with respect to the passage of time from the switching time t ₀ . The limiting rate R is a value obtained by subtracting the correction rate A from 1 (that is, R = 1−A). As shown in FIG. 3 (b), limit ratio R is set to an initial limit ratio R ₀ at time t _0, at the time t ₁ after being set to 0. Further, during the period from time t ₀ to time t ₁ (during a predetermined time Z), the limiting rate R is set to be gradually (smoothly) small.

That is, the output torque T of the motor 11 is most limited at the time t ₀ when the shift position SP is switched to the travel range, and thereafter the limit gradually decreases. In other words, the output torque control unit 4b performs a filtering process on the target torque T _{TGT by} using a limiting rate filter, sets the instruction torque T _C , and limits the output torque T.

The output torque control section 4b, because when the time from the time t ₀ of more than a predetermined time Z switching has elapsed, the correction factor A is always 1 (limit ratio R is always 0) is set to the target torque T set _TGT as indicated torque T _C, controls the inverter 13 to output the command torque T _C a motor 11 which is set. That is, after the rotational speed Np of the water pump 14 is increased to a predetermined speed Np _Q does not perform the torque limit T. Here, the correction rate map of FIG. 3A is stored in the inverter EUC2 in advance, and the output torque control unit 4b controls the output torque T of the motor 11 using this. In other words, the correction factor A is determined to a certain value by the time that has elapsed from the switching time t _0. Note that the limiting rate filter of FIG. 3B may be stored instead of the correction rate map.

[3. flowchart]
Next, an example of a control procedure executed by the inverter ECU 2 will be described with reference to FIGS. 4 (a) and 4 (b). 4A is a control flow P executed by the pump control unit 3, and FIG. 4B is a control flow M executed by the motor control unit 4. The flow P and the flow M operate independently of each other at a predetermined control cycle, and flag information of the flow P is transmitted to the flow M. Each of the following steps is performed by each function (means) assigned to the hardware of the computer being operated by software (computer program). When the power switch (power switch) is turned on, the vehicle control device starts flow P and flow M shown in FIGS. 4 (a) and 4 (b).

  As shown in FIG. 4A, in step P10 of the flow P, the shift position SP detected by the shift position sensor 25 is acquired from the vehicle ECU 1. In Step P20, it is determined whether or not the acquired shift position SP is in the P range or the N range. When the shift position SP is the P range or the N range, the process proceeds to step P30, the flag F is set to F = 0, the water pump (WP) 14 is stopped (step P40), and the flow P is returned. . That is, the life of the water pump 14 is ensured by stopping the water pump 14 when the motor 11 is stopped.

  On the other hand, when the shift position SP is not in the P range or the N range, the process proceeds to step P35, the flag F is set to F = 1, the water pump 14 is operated (step P45), and the flow P is returned. As a result, the inverter 13 is cooled by the water pump 14 while the motor 11 is in operation, so that overheating of the inverter 13 is suppressed. Here, the flag F is a variable for checking whether or not the shift position SP is in the travel range. When the flag F is F = 0, it means that the shift position SP is other than the travel range (P range or N range), and when the flag F is F = 1, the shift position SP is the travel range. Means. This flag F is used in the flow M.

  As shown in FIG. 4B, in step M10 of the flow M, it is determined whether or not the flag F is F = 1. In this step, it is determined whether or not the shift position SP is in the travel range, that is, whether or not the motor 11 is operating. If the flag F is set to F = 1 in step P35 of the flow P, it is determined in step M20 whether or not the flag G is G = 0. If the flag F is set to F = 0 in step P30 of the flow P, the process proceeds to step M100, and the flag G is set to G = 0.

Here, the flag G is a variable for checking whether or not the measurement by the timer is started, the flag G = 0 means that the timer measurement is not performed, and the flag G = 1 indicates that the timer is Means that measurement is in progress. When it is determined in step M10 that the flag F is F = 1, and in the subsequent step M20 that the flag G is determined to be G = 0, the shift position SP is switched from the P range or the N range to the traveling range. Since it is t ₀ at the time of switching, measurement by the timer is started in step M30. Thereby, the time on the horizontal axis of the correction factor map shown in FIG.

In the subsequent step M40, the flag G is set to G = 1, and in step M50, various information such as position information, opening degree information, and vehicle speed information is acquired from the vehicle ECU 1. In step M60, the target torque T _TGT is set from these various _{pieces of} information. Next, at step M70, the correction rate A at the timer measurement time t is obtained from the correction rate map. In step M80, the command torque T _C is set from the target torque T _TGT and the correction factor A, subsequent step M90, the set command torque T _C is transmitted to the inverter 13 is controlled motor 11 is flow M Is returned.

In the next control cycle, if the flag F is F = 1 (if the shift position SP remains in the travel range), the determination in step M20 proceeds from the NO route to step M50. Then, various information in this control cycle is acquired, and the target torque T _TGT is set again (step M60). Then, correction factor A corresponding to the counting time t of the timer in the control period is newly acquired (step M70), the command torque T _C at the time t is set (step M80). In step M90, motor control is executed, and these steps are executed repeatedly.

Further, when the shift position SP is switched from the travel range to the P range or the N range due to parking or waiting for a signal, in the flow P, the flag F is set to F = 0 in step P30 and the water pump 14 is stopped. The In the flow M, the process proceeds from the NO route to the steps M100 and M110 in step M10, the timer is stopped, and the measurement time t counted so far is reset. That is, when the shift position SP is switched to the P range or the N range, the time on the horizontal axis of the correction factor map is reset to zero. Next, when the shift position SP is switched to the travel range, the correction factor A corresponding to the elapsed time (timed time t of the timer) from the switching time t ₀ is acquired.

[4. effect]
Therefore, according to the vehicle control apparatus according to the present embodiment, since the water pump 14 is stopped before the shift position SP is switched to the travel range, unnecessary operation of the water pump 14 is suppressed as much as possible. Can ensure the service life. In this case, since the motor 11 does not generate torque, the inverter 13 is not likely to be overheated even if the water pump 14 is stopped.

Further, the water pump 14 is started when the shift position SP is switched to the travel range. However, it takes a certain amount of time for the water pump 14 to pass the flow rate (required flow rate) required for cooling the inverter 13 through the cooling passage 17. Therefore, in the present control device, when the shift position SP is switched to the travel range, the output torque T of the motor 11 is limited until the predetermined time Z elapses from the switching time t ₀ , thereby the predetermined time. Z suppresses the amount of heat generated by the inverter 13.

  That is, the inverter 13 is prevented from overheating by suppressing the output torque T of the motor 11 until the shift position SP is switched to the travel range and the water pump 14 can feed the necessary flow rate. And the inverter 13 can be protected. Therefore, according to this control device, it is possible to achieve both the life of the water pump 14 and the protection of the inverter 13.

Moreover, in order to restrict | limit the output torque T of the motor 11, the output torque T of the motor 11 can be restrict | limited with a simple control structure by using the correction factor map shown to Fig.3 (a). At this time, with the lapse of time from when switching t ₀ to the travel range of the gearshift position SP, since the limitation of the output torque T of the motor 11 is set to be smaller, the predetermined time from the switching time t ₀ Z When the time elapses, the output torque T does not suddenly increase, so that safety can be improved and drivability can be improved.

[5. Modified example]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above embodiment, when the output torque T of the motor 11 is limited, the correction rate map shown in FIG. 3A is used, and the correction is performed according to the passage of time from t ₀ when the shift position SP is switched to the travel range. Although the rate A is acquired, the method for limiting the output torque T of the motor 11 is not limited to the above.

For example, during the switching time t ₀ until a predetermined time Z has elapsed, in addition to the correction factor map in FIG. 3 (a), in a configuration that further restrict the output torque T of the motor 11 while monitoring the temperature H of the inverter 13 There may be. In this case, the vehicle 10 is provided with a temperature sensor (temperature acquisition means) 23 for detecting the temperature H of the inverter 13 as shown by a two-dot chain line in FIG. The temperature sensor 23 is provided, for example, in the vicinity of the switching element that easily generates heat inside the inverter 13, and outputs the temperature of the switching element as the representative temperature H of the inverter 13. The inverter temperature H detected by the temperature sensor 23 is transmitted to the inverter ECU 2 as needed.

Output torque control unit 4b, as in the above embodiment, the correction factor map shown in FIG. 3 (a), to obtain the correction factor A in accordance with the elapsed time from when switching t _0. Further, the correction rate B according to the temperature H of the inverter 13 is acquired from the map shown in FIG. 5A until the predetermined time Z elapses from the switching time t ₀ . Here, FIG. 5A shows a correction rate B for correcting the correction rate A (or the limit rate R) of the output torque T so that the limit of the output torque T increases as the temperature H of the inverter 13 increases. It is the map shown. That is, the correction rate B is set higher as the inverter temperature H is lower, and the correction rate B is set lower as the inverter temperature H is higher. The correction rate B is corrected to a lower value as the value is lower (that is, the correction rate B is corrected to increase the limit of the output torque T).

For example, when the correction factor A is A = 0.8 at a certain time t _X (t ₀ <t <t ₁ ), in the above embodiment, the command torque T _C is set to 0.8 times the target torque T _TGT. Here, the correction rate B corresponding to the inverter temperature H at this time t _X is further acquired, and a value obtained by multiplying the correction rate A by the correction rate B is further multiplied by the target torque T _TGT to obtain the command torque T _C. The correction rate B is a value such that the value of A × B is greater than 0 and 1 or less (0 <A × B ≦ 1). The limit of the output torque T is corrected by transmitting the command torque T _C thus set to the inverter 13 and controlling the motor 11.

  That is, the output torque control unit 4b corrects the output torque T of the motor 11 so that the limit is increased as the temperature H of the inverter 13 increases. As a result, the limit of the output torque T can be corrected while constantly monitoring the temperature H of the inverter 13, so that overheating of the inverter 13 can be reliably prevented. Furthermore, since the limitation of the excessive output torque T is suppressed, drivability can be improved.

  The means for obtaining the temperature H of the inverter 13 is not limited to the temperature sensor 23. For example, an outside air temperature sensor that detects the outside air temperature is provided, the inverter ECU 2 estimates the temperature rise of the inverter 13 based on the operation time of the inverter 13 and the magnitude of the current, and the temperature rise estimated to the temperature detected by the outside air temperature sensor May be added to obtain the temperature H of the inverter 13.

Further, as another example, between the switching time t ₀ until a predetermined time Z has elapsed, in addition to the correction factor map in FIG. 3 (a), the output torque of the motor 11 while monitoring the rotation speed Np of the water pump 14 The structure which restrict | limits T may be sufficient. That is, in the above-described embodiment, the water pump 14 is only subjected to on / off control by the pump control unit 3, but the flow rate discharged to the cooling passage 17 by controlling the rotation speed (rotational speed) Np of the water pump 14. It may be possible to control. In this case, the vehicle 10 is provided with a rotational speed sensor 24 for detecting the rotational speed Np of the water pump 14 as indicated by a two-dot chain line in FIG. 1, and the pump rotational speed Np detected by the rotational speed sensor 24. Is transmitted to the inverter ECU 2 as needed.

Output torque control unit 4b, as in the above embodiment, the correction factor map shown in FIG. 3 (a), to obtain the correction factor A in accordance with the elapsed time from when switching t _0. Further, the correction rate C corresponding to the rotational speed Np of the water pump 14 is acquired from the map shown in FIG. 5B until the predetermined time Z elapses from the switching time t ₀ . Here, FIG. 5B shows a correction rate for correcting the correction rate A (or the limit rate R) of the output torque T so that the limit of the output torque T becomes smaller as the rotational speed Np of the water pump 14 increases. It is the map which showed C. That is, the correction rate C is set lower as the pump speed Np is lower, and the correction rate C is set higher as the pump speed Np is higher. The correction rate C is corrected to a higher value as the value is higher (that is, the correction rate C is corrected to reduce the limit of the output torque T).

For example, when the correction factor A is A = 0.8 at a certain time t _X (t ₀ <t <t ₁ ), in the above embodiment, the command torque T _C is set to 0.8 times the target torque T _TGT. Here, the correction rate C corresponding to the pump rotational speed Np at this time t _X is further acquired, and a value obtained by multiplying the correction rate A by the correction rate C is further multiplied by the target torque T _TGT to obtain the command torque T _C. . The correction rate C is a value such that the value of A × C is greater than 0 and 1 or less (0 <A × C ≦ 1). The limit of the output torque T is corrected by transmitting the command torque T _C thus set to the inverter 13 and controlling the motor 11.

  That is, the output torque control unit 4b corrects so that the limit of the output torque T of the motor 11 becomes smaller as the rotation speed Np of the water pump 14 increases. Thereby, since it is possible to correct the output torque T while monitoring the cooling performance of the water pump 14, overheating of the inverter 13 can be reliably prevented. Furthermore, since the limitation of the excessive output torque T is suppressed, drivability can be improved.

Note that the output torque control unit 4b may correct the limit of the output torque T of the motor 11 using both the maps shown in FIGS. 5 (a) and 5 (b). That is, the command torque T _C may be set by multiplying the target torque T _TGT by the correction rate A and the correction rates B and C.

As still another example, the output torque T may be limited using a map as shown in FIG. 5C instead of the correction rate map shown in FIG. The map of FIG. 5C is stored in the inverter ECU 2 in advance, and an upper limit value _TUL of the output torque T is set. As shown in FIG. 5C, the upper limit value T _UL of the output torque T is set to be the lowest at the switching time t ₀ , and is gradually increased until the predetermined time Z is reached. Thereafter, the maximum torque T _MAX of the motor 11 is set.

When the set target torque T _TGT is equal to or higher than the upper limit value T _{UL at} that time, the output torque control unit 4b sets the upper limit value T _UL as the instruction torque T _C. On the other hand, when the target torque T _TGT is smaller than the upper limit value T _{UL at} that time, the target torque T _TGT is set as the command torque T _C. That is, the output torque control section 4b, when only the command torque T _C is clipped to the target torque T _TGT at the upper limit T _UL target torque T _TGT, which is set is equal to or higher than a preset upper limit T _UL To do. With such a configuration, the output torque T is limited only when it is really necessary, and drivability can be improved.

Further, the initial correction rate A ₀ in the correction rate map shown in FIG. 3A may be modified according to the inverter temperature H or the pump rotational speed Np. For example, the initial correction factor A ₀ is corrected to be higher as the inverter temperature H at the switching time t ₀ is lower, so that the torque limitation at the switching time t ₀ at which the output torque T is most limited is reduced and the drivability is improved. Can do.

  Further, the predetermined time Z in the correction factor map of FIG. 3A may be modified according to the pump rotation speed Np or the inverter temperature H. For example, in the above embodiment, the predetermined time Z is a fixed value set in advance. However, if the pump controller 3 can control the rotation speed Np of the water pump 14, the predetermined time Z is set to the pump rotation speed Np. The time during which the output torque T is limited can be changed by correcting according to the above. Thereby, in addition to ensuring the life of the water pump 14 and protecting the inverter 13, appropriate control in consideration of drivability can be performed.

The motor control method described here is an exemplification, and the output torque T of the motor 11 may be limited by a method other than these. In addition, although the maps described above have been exemplified as those that change gradually (smoothly), for example, a map that changes stepwise (stepwise) may be used.
Further, the shift position SP described above is an example, and ranges other than the above four ranges, such as an L range (low speed mode) and a B range (a mode in which the engine braking effect is enhanced in a hybrid vehicle or an electric vehicle), for example. May be provided. Further, the operating state of the motor 11 may be finely classified as in the MT vehicle. In such a case, the range in which the motor 11 is not in a no-load state (that is, the motor 11 is not stopped) is a travel range in which the motor 11 operates.

  Moreover, although the said embodiment demonstrated the example to which this control apparatus was applied to the electric vehicle 10, it is naturally possible to apply this control apparatus to the hybrid vehicle which uses an electric motor and an engine as a motive power source. The water pump is not limited to an electric pump as long as it is a hybrid vehicle, and may be driven by an engine.

1 Vehicle ECU
2 Inverter ECU
3 Pump control unit (pump control means)
4 Motor controller (motor control means)
4a Target torque setting unit 4b Output torque limiting unit 10 Electric vehicle (vehicle)
11 Motor (motor for vehicle power, electric motor)
12 Battery 13 Inverter 14 Water pump (pump)
15 Shift lever (shift device)
16 Accelerator pedal 17 Cooling passage 18 Radiator 23 Temperature sensor (temperature acquisition means)
24 Rotational speed sensor 25 Shift position sensor 26 Accelerator position sensor (APS)
27 Vehicle speed sensor t ₀ switching Z Predetermined time

Claims (4)

An inverter that generates AC power for driving a motor for vehicle power mounted on the vehicle;
A pump for feeding a cooling medium into a cooling passage for cooling the inverter;
A shift position sensor for detecting a shift position selected by a shift device for switching the operating state of the motor;
Pump control means for starting the pump when the shift position detected by the shift position sensor is switched to a travel range;
An upper limit value map set such that the upper limit value of the vehicle output torque of the motor is gradually increased from the time when the shift position is switched to the travel range;
A vehicle control device comprising: motor control means for setting the vehicle output torque of the motor based on the upper limit map when the shift position is switched to the travel range. The motor control means sets the upper limit value as the vehicle output torque from the upper limit map when the target torque requested by the driver is equal to or higher than the upper limit value at the time, and the target torque is the upper limit at the time. 2. The vehicle control device according to claim 1, wherein when the value is smaller than the value, the target torque is set to the vehicle output torque. 3. The vehicle control device according to claim 1, wherein the upper limit value is set to a maximum torque of the motor after a predetermined time from the time of the switching in the upper limit value map. 4. The vehicle according to claim 3, wherein the predetermined time is a time required for the rotation speed of the pump to increase to a rotation speed at which a predetermined flow rate required for cooling the inverter can be discharged from the time of the switching. Control device.

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