Patent Application
20150303860
The present invention relates to a motor drive device for a vehicle driving motor including a stator equipped with a coil and a rotor equipped with a magnet.
Regarding a vehicle driving motor for an electric vehicle, there is a known motor drive device that prevents an excessive temperature rise of the motor to avoid burnout of a coil or heat demagnetization of a magnet. For example, an invention described in PTL 1 is designed to reduce the temperature of a coil or a magnet by reducing torque of a motor when the temperature of the coil or the magnet rises.
Regarding a motor including a stator equipped with a coil and a rotor equipped with a magnet, heat generation by the coil is caused by electrical resistance and its heating value varies depending on size of motor torque. On the other hand, heat generation by the magnet is caused by changes of a magnetic flux piercing through the magnet and its heating value varies depending on the size of the motor torque and rotational frequency of the motor. Therefore, in a case of the coil, as the size of the motor torque becomes larger, the heating value increases and a coil temperature becomes high. Furthermore, in a case of a magnet 21, when the size of the motor torque becomes larger or the rotational frequency of the motor becomes higher, the heating value increases and a magnet temperature becomes high.
Accordingly, the cause of heat generation and the operation are different between the coil and the magnet. So, it is impossible to accurately detect the temperature of a rotor equipped with the magnet and prevent an excessive increase of the temperature only by measuring the coil temperature.
Furthermore, the magnet is embedded in the rotor which is a rotary part, so that it is impossible to measure the temperature by directly attaching a temperature sensor to the rotor.
The present invention solves the above-described problem and its object is to enable the high-accuracy detection of the temperature of the rotor which has been conventionally difficult.
In order to solve the above-described problem, for example, structures described in claims are adopted. The present application includes a plurality of means for solving the above-described problem; and as one example of such means, the present invention is characterized by “including a stator equipped with a coil, a case that secures the stator, a rotor supported by the case via bearings, and an internal air temperature detection unit that detects a temperature of internal air which is air filling the inside of the case.”
According to the present invention, the temperature of the rotor can be detected with a high degree of accuracy. Structures and advantageous effects other than those described above will be made clear by a description of embodiments below.
Embodiments for carrying out the present invention will be explained below with reference to drawings. The embodiments described below explain the present invention by taking, as an example, a case where the present invention is applied to a drive system of an electric car that uses an electric motor as a sole drive source for the car; however, the present invention can also be applied to a control device for electric motor vehicles such as railway vehicles or construction vehicles, and electric motor vehicles using engines, which are internal-combustion engines, and electric motors as vehicle drive sources, that are hybrid cars (passenger cars), freight vehicles such as hybrid trucks, omni-buses such as hybrid buses and the like, for example.
Furthermore, the following embodiments explain the present invention by taking, as an example, a case where the present invention is applied to a motor including a rotor equipped with a magnet; however, the invention is not limited to this example and the present invention can also be applied to a motor including a rotor which is not equipped with a magnet like an induction motor.
The inverter power source 3 converts direct-current power, which is supplied from the battery 1, into three-phase-alternating-current power by means of pulse width modulation (PWM) and supplies the three-phase-alternating-current power to the motor 2. The motor 2 converts electric energy, which is supplied as the three-phase-alternating-current power from the inverter power source 3, into kinetic energy. Kinetic power generated as the kinetic energy by the motor 2 is transmitted to a reduction gear 4, the speed is reduced by a gear-type speed reduction mechanism inside this reduction gear 4, and the kinetic power is then transmitted to right and left drive wheels 6 via a differential mechanism 5 and becomes a driving force to drive the vehicle.
The braking device 7 that puts brakes on the vehicle is provided near the drive wheels 6. The braking device 7 includes a hydraulic booster and a hydraulic control force generated by this hydraulic booster presses the drive wheels 6 to generate a frictional force. As a result, the kinetic energy is converted into thermal energy to put the brakes on the vehicle. The braking device 7 can reduce a rotational frequency of the motor 2 by putting the brakes on the vehicle.
Referring to
Referring to
The motor 2 generates heat according to an operational status. Accordingly, when the temperature of the motor rises excessively due to the heat generation, there is a possibility that varnish which is applied to the coil 24 may deteriorate. Additionally, the magnet 21 (such as a magnet using rare earth metal) has the property of being irreversibly demagnetized when becoming subject to a large reverse magnetic field at high temperature. Therefore, it is necessary to protect the coil 24 and the magnet 21 against an excessive temperature rise.
Cooling water 26 flows in the case 22 in order to cool the motor 2. The temperature of the motor 2 is reduced by transmitting the heat of the case 22 to this cooling water 26. A coil temperature sensor 16 is attached to the coil 24 in order to monitor the temperature of the coil 24.
Furthermore, an internal air temperature sensor 17 is attached via an internal-air-temperature-detection-point support member 18, which is composed of, for example, a ceramic structure, to the inner surface of the case 22 in order to measure the temperature of internal air 27, which is air filling the inside of the case 22, and have a magnet temperature estimation unit 32, which is included in the control calculation unit 8 described later, refer to the measured temperature. The internal air temperature sensor 17 does not directly contact the case 22 by interposing this internal-air-temperature-detection-point support member 18 between them.
Incidentally, the ceramic structure is used as the internal-air-temperature-detection-point support member 18 in this embodiment; however, instead of this, the internal-air-temperature-detection-point support member 18 may be a signal line for transmitting measurement information of the internal air temperature sensor 17 and this signal line may be extended to separate the internal air temperature sensor 17 from the inner surface of the case 22 for a certain distance, thereby attaching the internal air temperature sensor 17 to the inner surface of the case 22 in a manner such that the internal air temperature sensor 17 does not directly contact the case 22.
When the alternating current is applied to the coil 24, the coil 24 generates heat due to electrical resistance.
Each line L11 to L14 which represents the heat generating tendency is a curved line connecting operating points of the same heating value (heat generation amount). The alternating current applied to the coil 24 changes generally according to size (absolute value) of the motor torque. Accordingly, the heating value of the coil 24 increases according to the size of the motor torque and becomes larger in the order of L11<L12<L13<L14. If the motor torque is the same, there is little change in the heating value even if the rotational frequency changes, as can be seen in
On the other hand, the magnet 21 generates heat according to changes of a magnetic flux piercing through the magnet 21.
The heating value of the coil 24 changes according to the size of the motor torque (
In this way, the operating points of heavy heat generation are different between the coil 24 and the magnet 21 and an excessive temperature rise of the magnet 21 cannot be prevented only by measuring the temperature of the coil 24 by using the coil temperature sensor 16. Furthermore, since the coil 24 is provided on the stator 26 which is a non-rotary part, the coil temperature sensor 16 can be easily attached; however, since the magnet 21 is embedded in the rotor 20 which is a rotary part, it is difficult to directly attach the temperature sensor. Therefore, a means for estimating the temperature with a high degree of accuracy without providing the temperature sensor directly on the magnet 21 is required in order to prevent the excessive temperature rise of the magnet 21.
So, in this embodiment, the control calculation unit 8 is designed to calculate the temperature of the magnet 21 based on the heat generation of the motor 2 calculated from the operational status of the motor 2. As a result, the temperature of the magnet 21 which is embedded in the rotary part can be estimated without providing the magnet 21 with the sensor for detecting the temperature. Furthermore, accuracy to estimate the temperature of the magnet 21 is enhanced by using values detected by the coil temperature sensor 16 and the internal air temperature sensor 17.
The internal air temperature sensor 17 is attached to the case 22 via the internal-air-temperature-detection-point support member 18 as described above. The temperature of the internal air 27 can be measured highly accurately and the temperatures of the rotor 20 and the magnet 21 can be estimated more highly accurately by providing a space between the internal air temperature sensor 17 and the case 22 without having them directly in contact with each other.
Regarding the bearings 23, flows of heat exist between the bearings 23 and the rotor 20 and the case 22, respectively. Regarding the stator 25, flows of heat exist between the stator 25 and the case 22, the coil 24, and the internal air 27, respectively. Regarding the coil 24, flows of heat exist between the coil 24 and the stator 25 and the internal air 27, respectively. Regarding the internal air 27, flows of heat exist between the internal air 27 and the rotor 20, the case 22, the coil 24, and the stator 25, respectively. Regarding the rotor 20, flows of heat exist between the rotor 20 and the magnet 21, the bearing 23, and the internal air 27, respectively. Regarding the magnet 21, a flow of heat exists between the magnet 21 and the rotor 20.
In this embodiment, the temperatures of the rotor 20 and the magnet 21 are calculated by calculating the heat flows of the motor 2 based on the heat generated by the motor 2, which is calculated from the operational status of the motor 2, the relationship of heat flows of the motor 2 as illustrated in
The temperature of each part of the motor 2 is determined by inputs and outputs of heat generation by each part of the motor 2, heat transfer at each part of the motor 2, heat radiation from the case 22 to the external air, and heat radiation from the case 22 to the cooling water 26. Under this circumstance, an amount of heat transfer between the respective parts of the motor 2 is determined by temperature differences between the respective parts. Furthermore, an amount of heat radiation from the case 22 to the external air is determined by a temperature difference between the case 22 and the external air. An amount of heat radiation from the case 22 to the cooling water 26 is determined by a temperature difference between the case 22 and the cooling water 26.
Therefore, the temperature of each part of the motor 2, that is, the rotor 20 and the magnet 21, can be calculated from the heating value of each part of the motor 2, the temperature of the external air, and the temperature of the cooling water according to the flows of heat in
Now, since heat capacity of the motor 2 is large, the temperature of the motor 2 changes slowly relative to driving time of a general vehicle. Therefore, if an error occurs in the calculation process of heat flows, its influence continues for a long period of time, thereby degrading estimate accuracy of the temperatures of the rotor 20 and the magnet 21. So, in this embodiment, the estimate accuracy of the magnet temperature 21 is enhanced by using values detected by the coil temperature sensor 16 and the internal air temperature sensor 17.
Specifically speaking, in this embodiment, when the internal air temperature sensor 17 is used to measure the temperature of the internal air 27 and there is a difference between the calculated temperature of the internal air 27, which is calculated according to the flows of heat in
For example, when the calculated temperature of the internal air 27 is higher than the measured temperature, there is a high possibility that the calculated temperature of each part including the rotor 20 might be also calculated to be higher than its actual temperature. So, the calculated temperature of each part including the rotor 20 is corrected to a lower temperature. As a result, high accuracy of the estimated temperatures of the rotor 20 and the magnet 21 is achieved. Since the rotor 20 directly transmits and receives heat to and from the internal air 27 as shown in
Additionally, air has lower specific heat than that of metals and the temperature of the air easily changes. So, when the temperature of the rotor 20 changes, the temperature of the internal air 27 changes more quickly than, for example, the stator 25 and the case 22. Therefore, the temperatures of the rotor 20 and the magnet 21 can be corrected quickly by using the internal air temperature sensor 17 which measures the temperature of the internal air 27.
Furthermore, the temperature of the coil 24 tends to become the highest in the motor 2 and the temperature of the internal air 27 can be easily changed due to the temperature rise of the coil 24. Consequently, when the coil temperature sensor 16 is used to measure the temperature of the coil 24 and there is a difference between the calculated temperature of the coil 24 and the temperature measured by the coil temperature sensor 16, the temperature of each part including the internal air 27 is corrected according to this difference.
For example, when the calculated temperature of the coil 24 is higher than its measured temperature, there is a high possibility that the temperature of the internal air 27 is calculated to be higher than its actual temperature due to the influence of the coil 24. So, the calculated temperature of each part including the internal air 27 is corrected to a lower temperature. As a result, the influence of the coil 24 can be easily separated from among changes of the temperature of the internal air 27 and the temperatures of the rotor 20 and the magnet 21 can be estimated with a high degree of accuracy.
Then, when the thus-estimated temperature of the magnet 21 and the temperature detected by the coil temperature sensor 16 exceed a predetermined temperature, a command is issued to the inverter power source 3 to reduce the torque and rotational frequency of the motor 2 in this embodiment, thereby preventing an excessive temperature rise of the magnet 21 and the coil 24.
The operating points which tend to increase the temperature are different between the coil 24 and the magnet 21 as described above. Therefore, desired operations for the coil 24 and the magnet 21 to reduce the temperatures are different. So, in the first embodiment, the excessive temperature rise of the coil 24 and the magnet 21 is prevented by performing different protection operations between a case where the temperature of the coil 24 is high and a case where the temperature of the magnet 21 is high.
Specifically speaking, the heating value, that is, the motor torque may be limited according to the coil temperature in order to prevent the excessive temperature rise of the coil 24. When the coil temperature is comparatively low, permissible motor torque is comparatively large; and when the coil temperature is equal to or lower than a certain temperature, the motor torque up to the maximum torque in
Meanwhile, the heating value of the magnet 21 changes according to the size (absolute value) of the motor torque and the rotational frequency of the motor and a line having a constant heating value takes a form like each of the lines L21 to L24 shown in
The heat generated by the magnet 21 increases according to the size (absolute value) of the motor torque and the rotational frequency of the motor as described above. Therefore, when the rotational frequency of the motor is high even if the motor torque is reduced, there is a possibility that temperature of the magnet 21 may increase. For example, when a vehicle is running on a downhill grade, that is, when a load to increase the rotational frequency of the motor is imposed on the rotor 20, a vehicle speed, that is, the rotational frequency of the motor increases even if the motor torque is limited to zero. Under this circumstance, the heat generated by the magnet 21 increases and the magnet temperature continues to increase. Also, if an attempt is made to reduce the rotational frequency of the motor by adjusting the motor torque in this case, it is necessary to increase the motor torque on the regeneration side. In this case as well, the heat generated by the magnet 21 increases.
In this embodiment, when the rotational frequency of the motor increases even if the control calculation unit 8 sends a command to the inverter power source 3 to make the motor torque zero, the control calculation unit 8 sends a command to the braking device 7 to reduce the vehicle speed, that is, the rotational frequency of the motor. As a result, it is possible to reduce the rotational frequency of the motor and avoid the excessive temperature rise of the magnet 21.
Furthermore, if the control calculation unit 8 detects a failure of the internal air temperature sensor 17, the control calculation unit 8 corrects the calculated temperature by using only the value detected by the coil temperature sensor 16 without using the value detected by the internal air temperature sensor 17. Firstly, the control calculation unit 8 calculates the temperatures of the rotor 20 and the magnet 21 by calculating the flows of heat at the motor 2 based on the heat generated by the motor 2 which is calculated from the operational status of the motor 2, the heat flow relationship of the motor 2 as show in
The control calculation unit 8 is provided with a torque request calculation unit 30, a braking force request calculation unit 31, a magnet temperature calculation unit 32, a torque limit calculation unit 33, a rotational frequency limit calculation unit 34, a torque command calculation unit 35, and a braking force command calculation unit 36, respectively. The operation of each unit will be explained below.
In step S01, the torque request calculation unit 30 calculates a torque request of the motor 2 based on a vehicle speed signal input from the vehicle speed sensor 9 and an accelerator operation amount signal (a signal according to a step-in quantity of an accelerator pedal) input from the accelerator sensor 10. Specifically speaking, since the accelerator operation amount of the accelerator pedal is proportionate to an output request as the vehicle, the accelerator operation amount is converted into the output request. Then, a driving force request of the vehicle, that is, the torque request of the motor 2 is calculated by dividing that output request by the vehicle speed.
In step S02, the braking force request calculation unit 31 calculates a braking force request of the braking device 7 based on a brake operation amount signal (a signal according to a step-in quantity of a brake pedal) input from the brake sensor 11. Since the brake operation amount of the brake pedal is proportionate to a braking force request as the vehicle, the brake operation amount is converted into the braking force request. Incidentally, the braking force request is converted into a value corresponding to the motor torque and operates to reduce the speed of the vehicle, so that it becomes a negative value.
In step S03, the magnet temperature calculation unit 32 calculates the estimated temperature of the magnet 21 based on a temperature signal of the coil 24 which is input from the coil temperature sensor 16, a temperature signal of the internal air 27 which is input from the internal air temperature sensor 17, a temperature signal of the external air which is input from the external air temperature sensor 12, a temperature signal of the cooling water 26 which is input from the cooling water temperature sensor 15, a torque signal of the motor 2 which is input from the torque sensor 13, and a rotational frequency signal of the motor 2 which is input from the rotational frequency sensor 14.
Now,
Referring to
In step S032, the temperature calculation unit 42 calculates a current temperature of each part of the motor 2 based on the external air temperature which is input from the external air temperature sensor 12, the cooling water temperature which is input from the cooling water temperature sensor 15, the heating value of each part of the motor 2 which is calculated by the heat generation calculation unit 41, and a corrected temperature of each part of the motor 2 in the previous step, which is calculated by the temperature correction unit 45 described later.
The temperature of each part of the motor 2 is determined as described earlier by inputs and outputs of heat generation by each part of the motor 2, heat transfer at each part of the motor 2, heat radiation from the case 22 to the external air, and heat radiation from the case 22 to the cooling water 26. Under this circumstance, an amount of heat transfer between the respective parts of the motor 2 is determined by temperature differences between the respective parts. Furthermore, an amount of heat radiation from the case 22 to the external air is determined by a temperature difference between the case 22 and the external air. An amount of heat radiation from the case 22 to the cooling water 26 is determined by a temperature difference between the case 22 and the cooling water 26. Therefore, the current temperature of each part of the motor 2 can be calculated from the heating value of each part of the motor 2, the external air temperature, the cooling water temperature, and the temperature of each part of the motor 2 in the previous step.
In step S033, the coil temperature sensor failure judgment unit 43 judges whether the coil temperature sensor 16 has failed or not. For example, a thermistor is used as the coil temperature sensor 16. When the thermistor is disconnected, electrical resistance increases rapidly. Therefore, a failure caused by the disconnection of the thermistor can be detected by monitoring the electrical resistance. In this way, whether the coil temperature sensor 16 has failed or not is judged. If it is determined that the coil temperature sensor 16 has not failed, NO is determined for the judgment in step S033 and the processing proceeds to step S034. On the other hand, if it is determined in step S033 that the coil temperature sensor 16 has failed, the processing proceeds to step S035.
In step S034, the temperature correction unit 45 compares the estimated temperature of the coil 24 with the measured temperature of the coil 24 which is input from the coil temperature sensor 16, among the temperatures of the respective parts of the motor 2, which are calculated by the temperature calculation unit 42. When the estimated temperature is higher than the measured temperature, it is determined that the temperature of each part of the motor 2 is calculated to be higher than its actual temperature, and the estimated temperature of each part of the motor 2 is corrected to a lower temperature. If the estimated temperature is lower than the measured temperature, it is determined that the temperature of each part of the motor 2 is calculated to be lower than its actual temperature, and the estimated temperature of each part of the motor 2 is corrected to a higher temperature.
In step S035, the internal air temperature sensor failure judgment unit 44 judges whether the internal air temperature sensor 17 has failed or not. The failure judgment of the internal air temperature sensor 17 is also performed in the same manner as the aforementioned failure judgment of the coil temperature sensor 16. Specifically speaking, when a thermistor is used as the internal air temperature sensor 17, its electrical resistance is monitored and a failure caused by disconnection of the thermistor is detected. If it is determined that the internal air temperature sensor 17 has not failed, NO is determined for the judgment in step S035 and the processing proceeds to step S036. On the other hand, if it is determined in step S035 that the internal air temperature sensor 17 has failed, the processing proceeds to step S037.
In step S036, the temperature correction unit 45 compares the estimated temperature of the internal air 27 with the measured temperature of the internal air 27 which is input from the internal air temperature sensor 17, among the estimated temperatures of the respective parts of the motor 2. When the estimated temperature is higher than the measured temperature, it is determined that the temperature of each part of the motor 2 is calculated to be higher than its actual temperature, and the estimated temperature of each part of the motor 2 is corrected to a lower temperature. If the estimated temperature is lower than the measured temperature, it is determined that the temperature of each part of the motor 2 is calculated to be lower than its actual temperature, and the estimated temperature of each part of the motor 2 is corrected to a higher temperature.
In step S037, the magnet temperature selection unit 46: selects the temperature of the magnet 21 from the estimated corrected temperatures of the respected parts of the motor 2, which are calculated by the temperature calculation unit 42 when the coil temperature sensor 16 and the internal air temperature sensor 17 have not failed; and outputs the selected temperature to the torque limit calculation unit 33 and the rotational frequency limit calculation unit 34 described later.
Referring back to
In step S05, the rotational frequency limit calculation unit 34 calculates a rotational frequency limit for protecting the magnet 21 against the excessive temperature rise based on the estimated temperature of the magnet 21 which is input from the magnet temperature calculation unit 32. Incidentally, the correspondence relationship between the temperature of the magnet 21 and the rotational frequency limit is stored as a numerical map in the memory included in the control calculation unit 8. In step S05, the rotational frequency limit is calculated by searching this numerical map.
In step S06, the torque command calculation unit 35 calculates a torque command to be sent to the inverter power source 3 based on requested torque of the motor 2, which is input from the torque request calculation unit 30, and a torque limit of the motor 2 which is input from the torque limit calculation unit 33. The torque limit is a positive number, limits the torque request to the value equal to or less than the torque limit at power running, and limits the torque request to the value equal to or more than a positive/negative inverted value of the torque limit at regenerating. When the torque request is equal to or less than the torque limit at power running, the torque request is set as the torque command. If the torque request is equal to or more than the torque limit at power running, the torque limit is set as the torque command. When the torque request is equal to or more than the torque limit at regenerating, the torque request is set as the torque command. When the torque request is equal to or less than the torque limit at regenerating, the torque limit is set as the torque command.
In step S07, the braking force command calculation unit 36 calculates a braking force command to be sent to the braking device 7 based on a braking force request for the braking device 7 which is input from the braking force request calculation unit 31, the torque limit of the motor 2 which is input from the torque limit calculation unit 33, the rotational frequency signal of the motor 2 which is input from the rotational frequency sensor 14, and the rotational frequency limit of the motor 2 which is input from the rotational frequency limit calculation unit 34. When the rotational frequency of the motor increases even though the torque limit is zero, a command value that makes the rotational frequency of the motor equal to or less than the rotational frequency limit is set as the braking force command. In cases other than above, the braking force request is set as the braking force command. As a result, it is possible to reduce the rotational frequency of the motor and avoid the excessive temperature rise of the magnet 21.
The first embodiment is designed as described above so that the magnet temperature calculation unit 32, the torque limit calculation unit 33, and the rotational frequency limit calculation unit 34 are provided as shown in
Furthermore, even if the internal air temperature sensor 17 has failed, temperature information of each part of the motor can be calculated based on the temperature detected by the coil temperature sensor 16 and the drive status of the motor, that is, the external air temperature signal, the cooling water temperature signal, the torque signal, and the rotational frequency signal.
In the second embodiment, regarding the motor 2 in the first embodiment as shown in
In the third embodiment, regarding the motor 2 in the first embodiment as shown in
Furthermore, a coil temperature sensor signal line 51 which is a signal line of the coil temperature sensor 16 and an internal air temperature sensor signal line 52 which is a signal line of the internal air temperature sensor 17 can be integrated by attaching the internal air temperature sensor 17 to the stator 25, thereby making it possible to enhance assemblability of the motor 2.
Incidentally, in this embodiment, a ceramic structure is used as the internal-air-temperature-detection-point support member 18; however, instead of using this ceramic structure, the internal-air-temperature-detection-point support member 18 may be used as a signal line for transmitting measurement information of the internal air temperature sensor 17 and this signal line may be extended to attach the internal air temperature sensor 17 to the case 22 so that the internal air temperature sensor 17 will not directly contact the case 22.
The control calculation unit 8 according to the fourth embodiment is composed of: a first control calculation unit 61 that calculates the size of an electric current applied to the motor 2 and a frequency of the alternating current; and a second control calculation unit 62 that calculates a torque command of the motor 2. The first control calculation unit 61 and the second control calculation unit 62 have separate CPUs and memories, respectively, and signals can be sent and received between the first control calculation unit 61 and the second control calculation unit 62.
The second control calculation unit 62 mainly performs calculations which do not depend on the motor 2. The second control calculation unit 62 is connected to the vehicle speed sensor 9, the accelerator sensor 10, the brake sensor 11, and so on. The second control calculation unit 62 calculates the torque command of the motor 2 and sends it to the first control calculation unit 61, and calculates the braking force command and sends it to the braking device 7.
The first control calculation unit 61 mainly executes calculations specific to the motor 2. The first control calculation unit 61 is connected to the external air temperature sensor 12, the torque sensor 13, the rotational frequency sensor 14, the cooling water temperature sensor 15, the coil temperature sensor 16, the internal air temperature sensor 17, and so on. The first control calculation unit 61 calculates the size of the electric current applied to the motor 2 and the frequency of the alternating current based on the torque command sent from the second control calculation unit 62 and sends a command to the inverter power source 3, and also calculates the temperatures of the rotor 20 and the magnet 21 and sends them to the second control calculation unit 62.
Therefore, the first control calculation unit 61 has the functions of the magnet temperature calculation unit 32 in
Accordingly, program maintenability can be enhanced by employing the configuration in which execution parts are provided separately for the calculations specific to the motor 2 and for the calculations which do not depend on the motor 2. For example, when specifications of the vehicle are changed and properties of the motor 2 change, it is only necessary to modify only the first control calculation unit 61.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-259290 | Nov 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/078409 | 10/21/2013 | WO | 00 |
