CN112152543A

CN112152543A - Inverter device and vehicle control device

Info

Publication number: CN112152543A
Application number: CN202010573604.0A
Authority: CN
Inventors: 神田刚志
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2019-06-27
Filing date: 2020-06-22
Publication date: 2020-12-29
Also published as: JP2021005968A

Abstract

Provided are an inverter device and a vehicle control device, wherein the switching element can be protected from the aspect of thermal performance without increasing the size of the switching element to a necessary level or more, and sufficient torque can be ensured to cope with the situation such as an uphill slope or a step height difference. The inverter device (13) includes an inverter (31) and an inverter control unit (5) that controls the inverter (31). The inverter control unit (5) has a torque limiting unit (40), and the torque limiting unit (40) limits the torque of the motor (6) by a torque limiting value that includes: the number of revolutions determined by the number of revolutions of the motor (6) corresponds to a torque limit value; a short-time high-torque limit value for limiting the torque with a high torque that can be output by the motor (6) only for a short time. The torque limiting unit (40) uses, for the torque limitation, the larger one of the rotation number-corresponding torque limitation value and the short-time high torque limitation value at the time of starting the motor (6).

Description

Inverter device and vehicle control device

Technical Field

The present invention relates to an inverter device and a vehicle control device, which can protect a switching element and ensure sufficient torque to cope with an uphill slope, a step crossing, or the like.

Background

In a drive control device for controlling a drive motor of an electric vehicle or a hybrid vehicle, an alternating current is caused to flow through the motor by driving a plurality of switching elements. As shown in fig. 13, since the current flowing through the motor is changed for each phase according to the angle of the rotor, the direct current flows if the rotor is stopped. For example, in fig. 13, when a current is caused to flow in a state where the rotor is stopped at a phase angle of 90 °, a direct current as a peak current value of an alternating current flows in a line indicated by an arrow in fig. 14. When the motor is started at a place on an ascending slope or a step, when the electric vehicle or the like is not moving or starts traveling very slowly, a direct current is continuously passed through the motor, and a current is intensively passed through a specific switching element, so that there is a possibility that an abnormality occurs in the switching element.

In the conventional technique (1), when the number of rotations of the motor is equal to or less than a threshold value, the maximum torque of the motor is limited (patent document 1).

In the conventional technology (2), there is proposed a technology for protecting a switching element based on a temperature detected by a temperature sensor for detecting a temperature of the switching element and an estimated temperature limit torque estimated by a temperature estimating means for estimating the temperature of the switching element (patent document 2).

Documents of the prior art

Patent document

Patent document 1: JP 2007-331646A

Patent document 2: JP patent publication No. 2013-162732

Disclosure of Invention

Problems to be solved by the invention

In the conventional technique (1), since the maximum torque at the time of starting is limited, there is a possibility that it is impossible to climb a slope or to cross a step height difference. In a vehicle having a margin in the original output torque, this may not occur even when the torque is limited, but in many cases, this is not the case. In a vehicle having a small margin of output torque, since sufficient torque is generated at the time of starting, the size of the switching element which is not necessarily required during normal running is large, and the entire drive control device including the switching element is large in size and weight, and also high in cost.

In the conventional technique (2), although the estimated temperature of the switching element is accurate, when the estimated temperature is higher than the actual temperature of the switching element, there is a possibility that the torque for applying protection faster than the actual temperature is insufficient. When the estimated temperature is lower than the actual temperature of the switching element, the switching element cannot be protected even at the temperature at which the switching element is to be protected, and there is a possibility that an abnormality occurs in the switching element. In addition, the software becomes complicated.

In addition, in the case of the conventional technique (2), although the number of temperature sensors is smaller than that of the switching elements, when the temperature sensors are provided in all the switching elements and the torque is limited by the temperature, the torque is limited accurately, but the number of temperature sensors and detection circuits is increased, which increases the cost.

The present invention provides an inverter device and a vehicle control device, wherein the switching element is not increased to a degree larger than necessary size, the switching element can be protected from the aspect of thermal performance, and the torque enough to cope with the situations such as uphill slope or step height difference can be ensured.

Means for solving the problems

The inverter device 13 of the present invention includes: an inverter 31 for converting a direct current into an alternating current corresponding to the type of the motor 6 to be driven by opening and closing the switching element 4 made of a semiconductor of each phase; an inverter control unit (5), the inverter control unit (5) controlling the inverter (31),

the inverter control unit 5 includes a torque limiting unit 40, and the torque limiting unit 40 limits the torque of the motor 6 by a torque limit value;

the torque limit value includes:

the number of revolutions determined by the number of revolutions of the motor 6 corresponds to a torque limit value;

a short-time high-torque limit value that limits the torque with a high torque that can be output by the motor 6 only for a short time;

the torque limiter unit 40 uses, for the torque limitation, the larger one of the rotation number-corresponding torque limitation value and the short-time high torque limitation value at the time of starting the motor 6.

The "short time" and the "high torque" in the short-time high-torque limit value are short-time high torques at which abnormality of the switching element is not generated, for example, by one or both of a test and a simulation.

The above-mentioned "short time" takes, for example, several hundred ms. The "high torque" is a torque limit value that is greater than a torque limit value corresponding to the number of revolutions for a short time when a certain condition is satisfied.

The rotation number-corresponding torque limit value is set to be, for example, 0min even if the rotation number of the motor 6 is set to be^－1Even when the current is continuously supplied, the motor 6 and the switching element 4 do not generate a torque having an abnormal current value.

According to this configuration, when the rotation number corresponding torque limit value determined by the rotation number of the motor 6 is larger than the short-time high torque limit value that can be output only for a short time at the time of starting the motor 6, the rotation number corresponding torque limit value by selecting the rotation number of the motor 6 by the torque limiting section 40 is subjected to torque limitation corresponding to the motor rotation number, so that overload of the motor 6 can be suppressed, the switching element 4 is not increased to a degree larger than a necessary size, and the switching element 4 is protected from the thermal performance side.

When the short-time high torque limit value is larger than the rotation number corresponding torque limit value, the torque limiting unit 40 limits the torque by the high torque output only in the short time, and can secure a torque sufficient to cope with, for example, an uphill slope or a step height difference.

The torque limiter unit 40 may have a plurality of short-time high torque limit values. The plurality of short-time high-torque limit values may appear in sequence with the passage of time or may coincide with each other.

In the case where the plurality of short-time high-torque limit values appear sequentially with the lapse of time, for example, even when the first short-time high-torque limit value elapses by strongly or slowly depressing the accelerator pedal, the other short-time high-torque limit value appearing with the lapse of time can be used for the comparison with the torque limit value corresponding to the number of revolutions.

In the case where the plurality of short-time high-torque limit values have portions that overlap at the same time, the short-time high-torque limit value having the highest torque limit value may be used at the same time and compared with the torque limit value corresponding to the number of revolutions. For example, when the accelerator pedal is strongly depressed, a plurality of short-time high torque limit values are generated at substantially the same time, and the limit value with the lowest torque threshold value is the longest, so that high torque can be output at that time.

The inverter control unit 5 may have a function of calculating a torque control value for performing predetermined control on a torque command value input to the inverter control unit 5;

the torque limiter unit 40 sets TRQ2 as a short-TIME high torque limit for a permissible TIME (TIME _ ON1) from the TIME when the torque command value exceeds the threshold value when a set TIME elapses while the torque control value is equal to or less than the threshold value and the torque command value exceeds the threshold value. The short-TIME high torque limit value may be set to fall TIME Ts after the elapse of the allowable TIME (TIME _ ON1), and the torque limit value may be slowly decreased.

The threshold value is a threshold value arbitrarily determined by design or the like, and is determined by obtaining an appropriate time by one or both of a test and a simulation, for example.

The set time, the allowable time, and the fall time are each determined arbitrarily by design or the like, and are determined by obtaining an appropriate time by, for example, either or both of a test and a simulation. The fall time may be zero.

According to this aspect, by setting the condition that the short-time high-torque limit value is set to a state where the torque control value is equal to or less than the threshold value for a set time, even when the accelerator pedal is repeatedly depressed, the short-time high-torque limit value can be used for comparison of the torque limit value corresponding to the number of revolutions.

The torque limiter unit 40 may be provided so that the smaller the threshold value is, the longer the allowable time is. In other words, the larger the threshold value, the shorter the allowable time. The reason for this is that: since the temperature of the switching element 4 is also high if the torque limit value is high, the allowable time as the time during which high torque can be output is short.

The torque limiter unit 40 may include water temperature detection means 43 for detecting or estimating the temperature of the cooling water for cooling the inverter 31, and the torque limiter unit may be provided so as to increase the allowable time as the temperature of the cooling water detected or estimated by the water temperature detection means 43 decreases. By changing the length of the allowable time period in accordance with the temperature of the cooling water in this manner, it is possible to perform fine torque limitation.

The vehicle control device 16 according to the present invention is equipped with the inverter device 13 according to any one of the aspects of the present invention, and the motor 6 is a motor for driving the vehicle. According to this configuration, the inverter device 13 of the present invention achieves the aforementioned effects.

Any combination of at least 2 of the structures disclosed in the claims and/or the description and/or the drawings is encompassed by the present invention. In particular, any combination of 2 or more of the claims in the claims is also included in the present invention.

Drawings

The invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for illustrative and descriptive purposes only and should not be construed to limit the scope of the present invention. The scope of the invention is determined by the claims. In the drawings, like reference characters designate like or corresponding parts throughout the several views.

Fig. 1 is a block diagram showing a conceptual configuration of a vehicle in which a vehicle control device according to an embodiment of the present invention is mounted in a plan view;

fig. 2 is a block diagram showing a configuration example of an inverter device of the vehicle control device;

fig. 3 is a diagram showing a configuration example of an inverter in the inverter device;

fig. 4 is a diagram showing an example of a torque limit value corresponding to the number of revolutions set by the number of revolutions of the motor;

fig. 5 is a diagram showing an example of a short-time high torque limit value that can be output in a short time;

fig. 6 is a diagram showing an example of a condition for satisfying the short-time high-output limit value;

FIG. 7 is a diagram showing an example having a plurality of short-time high-output limit values;

FIG. 8 is a diagram showing another example having a plurality of short-time high-output limit values;

fig. 9 is a diagram showing an example of obtaining a final torque limit value;

fig. 10 is a diagram showing another example of determining the final torque limit value;

fig. 11 is a diagram showing still another example of obtaining the final torque limit value;

fig. 12A is a block diagram showing a conceptual configuration of a vehicle in which a vehicle control device according to another embodiment of the present invention is mounted in a plan view;

fig. 12B is a block diagram showing a conceptual configuration of a vehicle in which a vehicle control device according to still another embodiment of the present invention is mounted in a plan view;

FIG. 13 is a graph of a current waveform of a three-phase alternating current;

fig. 14 is a diagram showing an example of a line when a dc current flows.

Detailed Description

< embodiment 1 >

An embodiment of the present invention will be described with reference to fig. 1 to 11.

< concept of vehicle >

Fig. 1 is a block diagram showing a conceptual configuration of a vehicle in which a drive control device according to the present embodiment is mounted in a plan view. The vehicle is a 4-wheel electric vehicle in which wheels 2 constituting left and right rear wheels of a vehicle body 1 are driving wheels 2 and wheels 3 constituting left and right front wheels are driven wheels. The wheels 3 constituting the front wheels are steering wheels. The

wheels

2, 2 constituting the drive wheels are driven by a motor 6 for running that can be driven independently. Each motor 6 constitutes an in-wheel motor drive device IMM described later. A brake is provided on each

wheel

2, 3. The

wheels

3 and 3, which are steering wheels forming the left and right front wheels, can be steered by a steering mechanism not shown in the figure and steered by a steering mechanism 15 such as a steering wheel.

The motor 6 is a three-phase motor, for example, an embedded magnet type synchronous motor in which a permanent magnet is provided inside a core portion of a rotor. The motor 6 is a motor in which a radial gap is provided between a stator fixed to a housing and a rotor attached to a rotation output shaft.

< control System >

Fig. 2 is a block diagram showing a configuration example of an inverter device of the drive control device. As shown in fig. 1 and 2, the vehicle control device 16 includes a vehicle control ECU 14 as an electronic control unit, and the vehicle control ECU 14 performs control of the entire automobile; inverter devices 13, the inverter device 13 controlling the left and

right motors

6, 6 for driving in accordance with the torque command value of the vehicle control ECU 14; and (3) sensors. Where the vehicle is an electric vehicle, the vehicle control ECU is also referred to as a VCU (vehicle control unit).

As shown in fig. 1 and 2, the vehicle control ECU 14 includes a command torque calculation unit 14 a. The command torque calculation unit 14a is configured to set, as command torque values (command torques), acceleration and deceleration commands to be given to the left and

right motors

6 and 6, based on an acceleration command output from an acceleration sensor other than the illustrated one and a deceleration command output from a brake sensor other than the illustrated one. The acceleration sensor detects an operation amount of an acceleration operation mechanism 20 such as an accelerator pedal, and outputs an acceleration command in accordance with the detected operation amount. The brake sensor detects an operation amount of a brake operating mechanism 21 such as a brake pedal, and outputs a deceleration command in accordance with the detected operation amount. The command torque calculation unit 14a outputs the formed torque command value to each inverter device 13 so as to be distributed to the left and

right motors

6, 6.

As shown in fig. 2, each inverter device 13 includes a power supply circuit unit 28 and a motor control unit 29. The motor control unit 29 includes a motor drive control unit 30, a torque limiting unit 40, a rotation number detection means 41, and a water temperature detection means 43. The motor control unit 29 has a function of outputting information relating to detection values and control values of the in-wheel motor drive unit IWM (fig. 1) included in the motor control unit 29 to the vehicle control ECU 14.

Each power circuit unit 28 includes an inverter 31, and the inverter 31 converts direct current of the battery Bt (fig. 1) into three-phase alternating current for driving the motor 6; a PWM driver 32, the PWM driver 32 driving the inverter 31. As shown in fig. 2 and 3, the inverter 31 is a bridge circuit including upper and lower switching elements 4(UP, UN, VP, VN, WP, and WN) for each phase U, V, W, and converts direct current of the battery Bt (fig. 1) into analog sinusoidal three-phase alternating current by opening and closing the switching elements 4. The switching element 4 is a semiconductor switching element such as an IGBT or a MOS-FET. The output terminals of the respective phases of the inverter 31 are connected to the input terminals of the respective phases of the motor 6.

As shown in fig. 2, the motor control section 29 is constituted by a computer and programs and electronic circuits that operate therein, and the motor control section 29 includes a motor drive control section 30 as a control section constituting a basic configuration. The motor drive control unit 30 calculates a current command corresponding to a torque command value supplied from the vehicle control ECU 14 via the torque limiter unit 40, and performs current feedback control (the "predetermined control" in claim 3) for tracking the current command by obtaining the motor current detected by the current sensor 38. The motor drive control unit 30 calculates a voltage command corresponding to the torque control value by current feedback control, and supplies the voltage command to the PWM driver 32 of the power supply circuit unit 28. The motor control unit 29 and the PWM driver 32 constitute an inverter control unit 5 that controls the inverter 31.

The torque limiter 40 limits the torque of the motor 6 by the torque limit value. The torque limit value includes a torque limit value (fig. 4) corresponding to the number of revolutions determined by the number of revolutions of the motor 6 and a short-time high torque limit value (fig. 5) for limiting the torque by a high torque which can be output by the motor 6 only for a short time.

The torque limiter 40 uses the larger of the rotation number corresponding torque limit value and the short-time high torque limit value for the torque limitation at the time of starting the motor 6.

[ Torque limitation at Motor Start ]

< Torque limitation value corresponding to number of revolutions of Motor >

Fig. 4 is a diagram showing an example of the rotation number corresponding limit value set by the motor rotation number. Hereinafter, the description will be made with reference to fig. 2 as appropriate.

As shown in fig. 4 (a), when the rotation number of the motor 6 supplied from the rotation number detection means 41 is smaller than a threshold ROT1, the torque restriction unit 40 restricts the torque of the motor 6 to a torque restriction value TRQ1 equal to or smaller than the maximum torque.

Further, as shown in FIG. 4 (b), the number of revolutions of the motor 6 is 0min^－1The torque limit value TRQ1, whose torque limit value is equal to or less than the maximum torque, is increased as the number of revolutions of the motor 6 increases, and the maximum torque can be output at a certain number of revolutions ROT 2. In this case, since the torque smoothly rises, there is no phenomenon such as vibration. The rotation number detection means 41 obtains the rotation angle of the rotor of the motor 6 from the rotation angle detection means 33, and detects the rotation number of the motor 6 by, for example, performing a differentiation process or the like on the obtained rotation angle.

Even when the number of revolutions of the motor 6 is 0min^－1When the current is continuously supplied, torque limit value TRQ1 is set to a torque having a current value at which no abnormality occurs in both motor 6 and switching element 4 (fig. 3). Here, the number of revolutions of the motor 6 is used, but the torque limiter unit 40 may be controlled at a wheel speed corresponding to the number of revolutions ROT1 or ROT2 of the motor 6 by using a wheel speed.

< short-time high-torque limit value >

Fig. 5 is a diagram showing an example of a short-time high torque limit value.

As shown in fig. 2 and 5 (a), when a certain condition is satisfied, the torque limiter unit 40 sets TRQ2, which is greater than TRQ1 (fig. 4), as a torque limit value in a short TIME (allowable TIME) TIME _ ON 1. As shown in fig. 5 b, when the above condition is satisfied, the torque limit value is gradually decreased to 0 for the decrease TIME Ts after the elapse of the allowable TIME _ ON1 with TRQ2 larger than TRQ1 (fig. 4) as the torque limit value. In this case, after the elapse of the allowable TIME _ ON1, the torque limit value is gradually decreased, and the torque of the motor 6 is smoothly decreased, so that there is no vibration of the vehicle or the like.

Further, the short-TIME high torque limit value may be used for comparison with the torque limit value corresponding to the rotation number in accordance with the allowable TIME _ ON1 and the fall TIME Ts of the short-TIME high torque limit value extended from the allowable TIME _ ON 1.

< example of conditions for establishing short-time high-torque limit value >

Fig. 6 is a diagram showing an example of conditions for satisfying the short-time high torque limit value.

As shown in fig. 2 and 6, the torque limiter 40 sets TRQ2 to a short-TIME high torque limit value for an allowable TIME _ ON1 from the TIME when the torque limit value exceeds the threshold TRQThre1 when a set TIME (TIME _ OFF or more) elapses with the torque limit value being equal to or less than the threshold TRQThre1 as the above-described satisfaction condition and the torque command value exceeds the threshold TRQThre1 after the set TIME elapses.

At the allowable TIME _ ON1, the TIME at which the torque limit value is set to the over-threshold TRQThre1, the temperature is saturated, and the high torque TRQ2 is applied is set. When the inverter device 13 includes the water temperature detection means 43 for detecting or estimating the temperature of the cooling water for cooling the inverter 31, the torque limiter unit 40 may be configured to increase the temperature of the cooling water as the allowable TIME _ ON1 increases and decrease the allowable TIME _ ON1 as the temperature of the cooling water detected or estimated by the water temperature detection means 43 decreases.

For example, a water temperature sensor 42 is provided in a cooling water passage of the inverter 31, and the water temperature detection means 43 converts a measurement value, which is composed of a voltage or the like measured by the water temperature sensor 42, into a temperature. The temperature of the cooling water may be estimated from the temperature of the switching element 4 (fig. 3). The temperature of the cooling water may be estimated based on a temperature detection value when no current is applied to the switching element 4 (fig. 3) for detecting the temperature, or the temperature of the cooling water may be estimated based on a temperature increase value estimated based on a current applied to the switching element 4 (fig. 3) and the temperature detection value.

The set TIME equal to or longer than TIME _ OFF1 is set to a TIME when the switching element temperature falls to a predetermined temperature after the TIME _ ON1 elapses for the high torque TRQ 2. The TIME period longer than the TIME _ OFF1 is set to be a TIME period until the switching element temperature completely decreases, and thus may be a TIME period until the switching element temperature substantially decreases. The above-mentioned setting time is appropriately set by experiment or simulation.

< example of setting a plurality of short-time high-torque limit values >

Fig. 7 is a diagram showing an example having a plurality of short-time high-torque limit values.

As shown in fig. 2 and 7, it is also possible to form the torque limit value 40 with a plurality of short-time high torque limit values. When the torque limit value is increased slowly (gently), first, since the torque limit value exceeds the threshold TRQThre1, the high torque limit value 1 is TRQ2 for a short TIME and then gradually decreases during a period from TIME _ ON1 (for example, 500 ms).

In addition, since the torque limit value exceeds the threshold TRQThre2 if the torque limit value is raised, the short-TIME high torque limit value 2 is TRQ2 and then gradually decreases during the period from this TIME to TIME _ ON2 (e.g., 300 ms). In addition, since the torque command value exceeds the threshold TRQThre3 if the torque command value is increased, the short-TIME high torque limit value 3 is TRQ2 during the period from this TIME to TIME _ ON3 (e.g., 100 ms).

In the case where the short-TIME high-torque limit value is only 1 (short-TIME high-torque limit value 1), even in the case where the torque command value exceeds the threshold TRQThre1, the allowable TIME _ ON1 is ended before the maximum torque is generated if the torque command value itself is low, and thus the maximum torque is not applied even in the case where the torque command value is the maximum torque.

In contrast, when there are a plurality of short-time high torque limit values, the time for applying the maximum torque is set from when the threshold values TRQThre2 and TRQThre3 are exceeded, so that the maximum torque can be applied if the accelerator pedal is depressed.

By providing a plurality of short-time high-torque limit values in this manner, it is possible to cope with a case where the accelerator pedal is depressed slowly or a case where the accelerator pedal is depressed strongly. Further, if TRQThre1 < TRQThre2 < TRQThre3 is set, the TIME is set so as to be in the relationship of TIME _ ON1 > TIME _ ON2 > TIME _ ON 3. The reason for this is that: since the temperature of the switching element 4 (fig. 3) is also high if the torque limit value is high, the time for generating high torque by that amount is short.

Fig. 8 is a diagram of another example having a plurality of short-time high-torque limit values.

In fig. 8, the torque command value is abruptly increased. In this case, the 3 short-time high torque limit values are TRQ2 at substantially the same timing.

< example of obtaining Final Torque Limit value >

Fig. 9 is a diagram showing an example of obtaining the final torque limit value.

When the accelerator pedal is depressed, the short-time high torque limit value that is higher than the torque limit value by the number of revolutions of the motor is raised at time T1, and the final torque limit value is formed. After the lapse of time, the short-time high torque limit value is decreased, and conversely, the motor rotation number is increased, whereby the torque limit value by the rotation number is increased, and therefore, from the midway (time T2), the torque limit value by the rotation number becomes the final torque limit value.

Fig. 10 is a diagram showing another example of determining the final torque limit value when the motor rotation number does not increase. In this case, the short-time high torque limit value, which is higher than the torque limit value of the rotation number of the motor, is increased at the time point of time T1 when the accelerator pedal is depressed, and thus the final torque limit value is formed. Then, when the short-time high torque limit value is smaller than the rotation number-caused torque limit value TRQ1, the rotation number-caused torque limit value becomes the final torque limit value.

For example, when the torque command value is slowly increased and the motor is not rotated, as shown in fig. 11, the short-time high torque limit value is increased at time T3, which is higher than the torque limit value due to the number of rotations of the motor, and thus the final torque limit value is formed. Then, at time T4 to T5 when the short-time high torque limit value is smaller than the rotation number-based torque limit value TRQ1, the rotation number-based torque limit value becomes the final torque limit value. At the time T5, the short-time high torque limit value is higher than the torque limit value TRQ1 due to the number of revolutions, and therefore the short-time high torque limit value is the final torque limit value. Since the torque limit value by the number of revolutions is higher than the short-time high torque limit value at time T6 thereafter, the torque limit value by the number of revolutions is the final torque limit value.

< Effect >

According to the inverter device 13 described above, at the time of starting the motor 6, the switching element 4 can be protected by the torque limitation by the number of revolutions of the motor in the case where the switching element 4 is not larger than a necessary size. In addition, since a short-time high torque limit, for example, several hundred ms, is allowed to be output, the motor 6 can be started even at an uphill or a level difference. The case where there are a plurality of short-time high torque limit values can also correspond to the case where the accelerator pedal is depressed hard or slowly. The case where the torque limit value is continuously equal to or less than the threshold value is set as the condition for raising the torque limit value for a short time, and this can be handled also in the case where the accelerator pedal is repeatedly depressed.

< Another embodiment >

In the following description, the same reference numerals are used for parts corresponding to the items described earlier in each embodiment, and redundant description is omitted. When only a part of the structure is described, the other parts of the structure are the same as those described above unless otherwise specified. The same structure realizes the same effect. Not only the combinations of the parts specifically described by the modes of implementation may be made, but also the modes of implementation may be partially combined if not particularly hindered.

The in-wheel motor driving device may be a cycloidal type speed reducer, a planetary speed reducer, a 2-axis parallel speed reducer, or another speed reducer.

In the above-described embodiment, the example in which the vehicle control device is employed in the electric vehicle having the in-wheel motor drive device was described, but the vehicle control device may be provided in a 2-motor vehicle-mounted type vehicle in which 2

motors

6, 6 and

speed reducers

7, 7 corresponding to the motors 6 are provided in the vehicle body 1 and the

wheels

3, 3 as the left and right drive wheels are driven by the

motors

6, 6 as shown in fig. 12A.

As shown in fig. 12B, the vehicle control device may be provided in a 1-motor vehicle-mounted type vehicle in which the

wheels

2, 2 as left and right drive wheels are driven by 1 motor 6 mounted on the vehicle body 1.

In fig. 1, 12A, and 12B, the left and right driving wheels driven by the motor 6 may be either front or rear wheels. In addition, four-wheel drive is also possible. The motor 6 may be a direct motor that drives the drive wheels without interposing a reduction gear.

The inverter device according to the embodiment may be mounted not only on a vehicle but also on, for example, an equipment gallery, an industrial machine, or the like.

The embodiments for carrying out the invention according to the embodiments have been described above, and the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above description but by the claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Description of the reference numerals

Reference numeral 4 denotes a switching element;

reference numeral 5 denotes an inverter control section;

reference numeral 6 denotes a motor;

reference numeral 13 denotes an inverter device;

reference numeral 16 denotes a vehicle control device;

reference numeral 31 denotes an inverter;

reference numeral 40 denotes a torque limiter;

reference numeral 43 denotes a water temperature detection mechanism.

Claims

1. An inverter device, comprising: an inverter that converts a direct current into an alternating current corresponding to a form of a motor to be driven by opening and closing switching elements made of semiconductors of respective phases; an inverter control unit that controls the inverter;

the inverter control unit includes a torque limiting unit that limits a torque of the motor by a torque limit value,

the torque limit value includes:

a torque limit value corresponding to a rotation number determined by the rotation number of the motor;

a short-time high-torque limit value for limiting the torque with a high torque that can be output by the motor only for a short time,

the torque limiting unit uses, for the torque limitation, a larger one of the rotation number-corresponding torque limitation value and the short-time high torque limitation value at the time of starting the motor.

2. The inverter device according to claim 1, wherein the torque limiting unit has a plurality of short-time high torque limit values.

3. The inverter device according to claim 1 or 2, wherein the inverter control unit has a function of calculating a torque control value for performing predetermined control on a torque command value input to the inverter control unit;

the torque limiting unit sets the high torque as the short-time high torque limit value for an allowable time from a time point when the torque command value exceeds the threshold value when a set time elapses after the torque control value is equal to or less than the threshold value.

4. The inverter device according to claim 3, wherein the torque limiting unit is provided so that the smaller the threshold value is, the longer the allowable time is.

5. The inverter device according to claim 3, comprising water temperature detection means for detecting or estimating a temperature of the cooling water for cooling the inverter, wherein the torque limiter unit is provided so as to increase the allowable time as the temperature of the cooling water detected or estimated by the water temperature detection means is lower.

6. A vehicle control device on which the inverter device according to any one of claims 1 to 5 is mounted, wherein the motor is a motor for driving a vehicle.