JP2019129577A - Refrigerant temperature estimation device - Google Patents

Abstract

To provide a refrigerant temperature estimation device of a motor generator capable of accurately acquiring refrigerant temperature of the motor generator by using no refrigerant temperature sensor.SOLUTION: A refrigerant temperature estimation device 1 estimates temperature of a refrigerant of a motor 21 in a vehicle including an engine 20 and a motor 21. The refrigerant temperature estimation device 1 comprises: a motor temperature sensor 11 for acquiring temperature of the motor 21; a water temperature sensor 12 for acquiring temperature of the engine 20; an intake air temperature sensor 13 for acquiring outside air temperature; a motor rotation speed sensor 14 and an inverter 25 for acquiring a parameter relating to a travel state of a vehicle V; and an ECU 10 for estimating temperature of the refrigerant of the motor 21 on the basis of temperature of the engine 20, temperature of the motor 21, the outside air temperature, and an estimation formula into which the above parameters are input.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a refrigerant temperature estimation device.

  Conventionally, there has been known a rotating electrical machine in which a refrigerant temperature sensor is disposed on the outer peripheral surface of a coil end in order to perform heat protection of the coil and the cooling oil (for example, Patent Document 1).

JP 2013-31822 A

  In the above-mentioned prior art, the refrigerant temperature of the rotating electrical machine is directly obtained by the refrigerant temperature sensor. In this case, the cost of the refrigerant temperature sensor is increased, and there is a risk of failure of the refrigerant temperature sensor. Therefore, in recent years, it has been studied to acquire the refrigerant temperature of the motor generator without using the refrigerant temperature sensor.

  An object of this invention is to provide the refrigerant | coolant temperature estimation apparatus which can estimate the refrigerant | coolant temperature of a motor generator, without using a refrigerant | coolant temperature sensor.

  In order to solve the above-mentioned problems, the present inventor has made extensive studies, and as a governing factor of the refrigerant temperature of the motor generator based on experimental data, the temperature of the motor generator, the temperature of the internal combustion engine, the outside air temperature, The inventors have found that the refrigerant temperature of the motor generator can be estimated based on an estimation formula that uses parameters related to the traveling state of the vehicle as input, and the present invention has been completed.

  A refrigerant temperature estimation device according to the present invention is a refrigerant temperature estimation device that estimates the temperature of a refrigerant of a motor generator in a vehicle including an internal combustion engine and a motor generator, and acquires the temperature of the motor generator. , A second acquisition unit for acquiring the temperature of the internal combustion engine, a third acquisition unit for acquiring the outside air temperature, a fourth acquisition unit for acquiring parameters related to the traveling state of the vehicle, a temperature of the motor generator, an internal combustion engine And an estimation unit that estimates the temperature of the refrigerant of the motor generator based on an estimation formula using the temperature, the outside air temperature, and the parameters as inputs.

  In the refrigerant temperature estimation device according to the present invention, the estimation unit estimates the temperature of the motor generator refrigerant based on an estimation formula that receives the motor generator temperature, the internal combustion engine temperature, the outside air temperature, and parameters. The Therefore, it is possible to estimate the refrigerant temperature of the motor generator without using the refrigerant temperature sensor using the above knowledge.

  In the refrigerant temperature estimation device according to the present invention, the estimation unit calculates time average values of the motor generator temperature, the internal combustion engine temperature, the outside air temperature, and the parameters, and inputs the calculated time average value to the estimation formula. As an alternative, the temperature of the refrigerant may be estimated. In this case, for example, the refrigerant temperature of the motor generator is appropriately estimated even when the time constant of the parameter relating to the running state of the vehicle is shorter than the time constants of the motor generator temperature, the internal combustion engine temperature, and the outside air temperature. It becomes possible to do.

  More specifically, as a case where the above-described effects are preferably achieved, the parameters may include the rotational speed of the motor generator and the torque of the motor generator.

As a case where the above-described effects are preferably achieved, specifically, the estimation unit uses k ₁ × T ₁ , k ₂ × T ₂ , k ₃ × N, k ₄ × TQ, and k ₅ × T as estimation equations. The temperature of the refrigerant may be estimated by a polynomial that is a sum of a plurality of terms including at least _three .
However,
T ₁ : Time average value of motor generator temperature
T ₂ : Time average value of the temperature of the internal combustion engine
T ₃ : Time average value of outside temperature
N: Time average value of motor generator speed
TQ: Time average value of absolute value of motor generator torque
k ₁ , k ₂ , k ₃ , k ₄ , k ₅ : predetermined coefficients

  According to the present invention, the refrigerant temperature of the motor generator can be estimated without using the refrigerant temperature sensor.

Drawing 1 is a schematic structure figure of vehicles provided with a refrigerant temperature estimating device of an embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of the motor generator of FIG. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a block diagram of the refrigerant temperature estimation device of FIG. FIG. 5 is a flowchart showing processing of the refrigerant temperature estimation device of FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements will be denoted by the same reference symbols, without redundant description.

  As shown in FIG. 1, the refrigerant temperature estimation device 1 is mounted on a vehicle V. The vehicle V is, for example, a hybrid vehicle that includes an engine (internal combustion engine) 20 and a motor (motor generator) 21 as driving power sources. The vehicle V is a commercial vehicle such as a bus or a truck. The vehicle V is not particularly limited, and may be a large vehicle, a medium vehicle, a small vehicle, or the like. Below, after demonstrating the structure of the vehicle V and the structure of the motor 21, the structure of the refrigerant | coolant temperature estimation apparatus 1 is demonstrated first.

[Configuration of Vehicle V]
The vehicle V includes an ECU (Electronic Control Unit) 10, an engine 20, a motor 21, an AMT (Automated Manual Transmission) 22, a battery 24, and an inverter 25. The AMT 22 includes a clutch 23, and the engine 20 and the motor 21 are disposed along the front-rear direction of the vehicle V in the vehicle V, and are connected to each other via the clutch 23. The motor 21 is disposed behind the vehicle V with respect to the engine 20. The Fr direction of the arrow in FIG. 1 corresponds to the forward direction of the vehicle V.

  The ECU 10 is an electronic control unit having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a controller area network (CAN) communication circuit, and the like. In the ECU 10, for example, various functions are realized by loading a program stored in the ROM into the RAM and executing the program loaded in the RAM by the CPU. The ECU 10 is communicably connected to the engine 20, the motor 21, the AMT 22, the clutch 23, the battery 24, and the inverter 25. As an example, the ECU 10 is integrally configured to perform comprehensive control for causing the vehicle V to function as a hybrid vehicle. The ECU 10 may be configured of a plurality of electronic units.

  The engine 20 is a diesel engine, for example. The operation of the engine 20 is controlled by the ECU 10. The engine 20 may be an internal combustion engine such as a gasoline engine or a natural gas engine.

  The motor 21 is a motor generator (motor generator) having both the function of a motor and the function of a generator. The motor 21 is driven by the electric power of the battery 24 and functions as a driving force source for the vehicle V. In addition, when the vehicle V decelerates, the regenerative braking force is applied to the wheels W of the vehicle V to generate electric power and charge the battery 24. It also functions as a generator. The configuration of the motor 21 will be described in detail later. The operation of the motor 21 is controlled by the ECU 10.

  The AMT 22 is configured as a mechanical automatic transmission, and automatically performs shift operations such as changing (shifting) the gear position (gear position) and controlling connection and disconnection of the clutch 23. The operation of the AMT 22 and the clutch 23 is controlled by the ECU 10.

  The AMT 22 transmits the driving force of the engine 20 and the motor 21 to the wheels W via a propeller shaft, a differential gear, a drive shaft, and the like. More specifically, when the clutch 23 is disengaged, only the driving force of the motor 21 is transmitted to the wheel W and used as a driving force for propelling the vehicle V. On the other hand, when the clutch 23 is connected, the driving force of the engine 20 and the motor 21 is transmitted to the wheel W and used as a driving force for propelling the vehicle V.

  The battery 24 is various secondary batteries such as a lithium ion battery. The battery 24 is charged with electric power supplied from the inverter 25. The state of the battery 24 is monitored by the ECU 10.

  The inverter 25 is electrically connected to the motor 21 and the battery 24. The inverter 25 converts the power input from the battery 24 into an alternating current, and outputs the converted power to the motor 21. The inverter 25 also converts the power input from the motor 21 into direct current, and outputs the converted power to the battery 24. The operation of the inverter 25 is controlled by the ECU 10.

[Configuration of motor 21]
Next, the configuration of the motor 21 will be described with reference to FIGS. 2 and 3. The motor 21 is an electric machine that functions as an electric motor and a generator. As shown in FIGS. 2 and 3, the motor 21 includes a housing 2, a rotating shaft 3, a rotor 4, and a stator 5.

  The housing 2 functions as a housing for the motor 21. The housing 2 penetrates the rotation shaft 3 and supports the rotation shaft 3 so as to be rotatable. In the housing 2, an accommodation space S for accommodating the rotor 4 and the stator 5 is formed. In the accommodation space S, oil FL for cooling the stator 5 and the like is stored.

  The housing 2 has an airtight structure in which the oil FL stored in the housing space S does not leak from the housing space S. The housing 2 is not provided with a circulation path for circulating the oil FL outside the housing 2, and the oil FL is accumulated only in the accommodation space S in the housing 2. The oil FL can be replaced by disassembling the housing 2 or the like.

  The oil FL functions as a lubricant such as an oil seal and a bearing (not shown) and also functions as a refrigerant for the motor 21. The oil FL is not particularly limited, and for example, ATF can be used. The amount of the oil FL stored in the housing space S of the housing 2 may be an amount that allows a part of the rotor 4 and the stator 5 to be immersed in the oil FL.

  The rotation shaft 3 is an output shaft that outputs rotational driving force when the motor 21 functions as a motor, and is an input shaft to which rotational driving force is input when the motor 21 functions as a generator.

  The rotor 4 is disposed in the accommodation space S and is rotatably provided in the housing 2 by being fixed to the rotating shaft 3. The rotation axis direction of the rotor 4 is the same as the rotation axis direction of the rotation shaft 3. The rotor 4 includes a disc-shaped rotation support 4 a fixed to the rotation shaft 3 and a plurality of permanent magnets 4 b arranged at the outer peripheral end of the rotation support 4 a. The permanent magnet 4b is, for example, a neodymium magnet.

  The rotation support portion 4 a is fixed to the rotation shaft 3 and extends outward in the radial direction of the rotation shaft 3 with the rotation shaft 3 as a center. On the outer peripheral surface of the rotation support portion 4a, permanent magnets 4b having an N polarity on the outer peripheral side and permanent magnets 4b having an S polarity on the outer peripheral side are alternately arranged. The permanent magnet 4b is fixed to the rotation support portion 4a by a bolt 4c and a pair of pressing plates 4d.

  The stator 5 is disposed in the accommodation space S. The stator 5 is fixed to the inner peripheral surface of the housing 2 forming the housing space S, and is disposed on the outer peripheral side of the permanent magnet 4 b (rotor 4). The stator 5 has an iron core (not shown) and a coil (not shown) of an electric wire wound around the iron core. When the motor 21 functions as an electric motor, the rotor 4 is rotated by switching the direction of the current flowing through the coil of the stator 5, and when the motor 21 functions as a generator, the rotor 4 rotates to the coil of the stator 5. Current is excited.

  In the motor 21, when the rotor 4 rotates, the oil FL stored in the accommodation space S is scraped up by the pressing plate 4d. As a result, oil FL is applied to the entire circumference of the stator 5 and the stator 5 is cooled. That is, the motor 21 is an oil cooling type.

  Then, with reference to FIGS. 1-4, the structure of the refrigerant | coolant temperature estimation apparatus 1 is demonstrated. The refrigerant temperature estimation device 1 is a device for estimating the temperature of the refrigerant of the motor 21 in the vehicle V. For example, the refrigerant temperature estimation device 1 estimates the temperature of the refrigerant of the motor 21 at least while the vehicle V is traveling.

[Configuration of Refrigerant Temperature Estimation Device 1]
As shown in FIG. 4, the refrigerant temperature estimation device 1 includes an ECU (estimation unit) 10, a motor temperature sensor (first acquisition unit) 11, a water temperature sensor (second acquisition unit) 12, and an intake air temperature sensor ( (3rd acquisition part) 13, The motor rotation speed sensor (4th acquisition part) 14, and the above-mentioned inverter (4th acquisition part) 25 are comprised. The water temperature sensor 12, the intake temperature sensor 13, and the motor rotational speed sensor 14 are communicably connected to the ECU 10. The motor temperature sensor 11 is communicably connected to the ECU 10 via the inverter 25.

  The motor temperature sensor 11 is a thermistor attached to the stator 5 of the motor 21, for example, and acquires the temperature of the stator 5 as the motor temperature (the temperature of the motor 21). The motor temperature sensor 11 transmits the acquired temperature signal of the stator 5 to the ECU 10. The water temperature sensor 12 is, for example, a thermistor provided in a cooling water channel of the engine 20 and acquires the water temperature of the engine 20 as the engine temperature (the temperature of the engine 20). The water temperature sensor 12 transmits a signal of the obtained water temperature to the ECU 10. The intake air temperature sensor 13 is a thermistor provided in an air cleaner of the engine 20, for example, and acquires the intake air temperature of the engine 20 as the outside air temperature. The intake air temperature sensor 13 transmits the acquired intake air temperature signal to the ECU 10.

  The motor rotation speed sensor 14 is, for example, a rotation angle sensor (so-called resolver) provided in the motor 21 and acquires the rotation speed of the rotating shaft 3 of the motor 21 as the motor rotation speed (rotation speed of the motor generator). . The motor rotation speed sensor 14 transmits the acquired signal of the rotation speed of the rotation shaft 3 of the motor 21 to the ECU 10 via the inverter 25.

  The inverter 25 calculates the torque of the motor 21 (motor torque) based on the power output to the motor 21 and the power input from the motor 21. When power is output to the motor 21, the inverter 25 may calculate the motor torque (raw value) with a positive sign. When power is output from the motor 21, the inverter 25 may calculate the motor torque (raw value) with a negative sign. The inverter 25 transmits the calculated torque signal of the motor 21 to the ECU 10.

[Estimation of Oil FL Temperature by ECU 10]
The estimation of the temperature of the oil FL (refrigerant temperature) will be described in detail. The ECU 10 estimates the temperature of the oil FL of the motor 21 based on an estimation formula that receives the engine temperature, the motor temperature, the motor rotation number, the motor torque, and the outside air temperature. First, various parameters that are input to the estimation formula will be described.

  In the above estimation formula, the engine temperature, the motor temperature, and the outside air temperature are temperature parameters representing the temperature. In particular, the engine temperature, the motor temperature, and the outside air temperature can be regarded as temperature parameters related to the heat source that causes the temperature change of the oil FL directly or indirectly in the vehicle V.

  For example, the engine 20 is a heat source that causes a temperature change of the oil FL in that heat can be transferred from the cylinder block (not shown) of the engine 20 to the housing 2 of the motor 21 to raise the temperature of the oil FL. It can be said.

  Further, for example, the temperature change of the oil FL occurs in that the temperature of the oil FL can be raised by the heat from the inner wall surface of the housing 2 of the motor 21 and the heat taken from the stator 5 of the motor 21 It can be said that it is a heat source to be generated.

  Further, for example, the outside air can be said to be a heat source that causes a temperature change of the oil FL in that the temperature of the oil FL can be lowered by taking heat from the surface of the housing 2 of the motor 21 through the running wind. .

  In the vehicle V, the engine 20 and the motor 21 are disposed along the front-rear direction of the vehicle V in the vehicle V, and the motor 21 is disposed rearward of the engine 20 with respect to the vehicle V. In this case, while the vehicle V is traveling, the outside air (running wind) flowing from the front to the rear of the vehicle V is heated from the surface of the cylinder block of the engine 20 before reaching the surface of the housing 2 of the motor 21. It is warmed by. That is, the temperature of the oil FL can be increased also in that the engine 20 can transfer heat from the surface of the cylinder block of the engine 20 or the like to the housing 2 of the motor 21 via traveling wind to raise or lower the temperature of the oil FL. It can be said that it is a heat source that causes change.

  In the above estimation formula, the motor rotation speed and the motor torque are parameters relating to the running state of the vehicle V. The parameters relating to the traveling state of the vehicle V include, for example, various measured values and control values related to the magnitude of the driving force for causing the vehicle V to travel (for example, motor torque, electric power supplied to the motor 21, motor 21 Actual measurement value or target value such as current supplied to the vehicle, and various measurement values and control values (for example, motor rotation speed, engine rotation speed, vehicle speed etc.) related to the speed of the traveling wind generated by the traveling of the vehicle V Actual measured value or target value).

  The motor rotational speed can be regarded as a parameter that can directly contribute to the temperature change of the oil FL. The temperature change of the oil FL is also caused by the heating of the oil FL due to the stirring resistance when the pressing plate 4d or the like scoops up the oil FL. The stirring resistance changes in accordance with the motor rotation number corresponding to the rotation number of the rotor 4. In this respect, the motor rotation speed can be regarded as a parameter that can directly contribute to the temperature change of the oil FL.

  Alternatively, the motor rotation speed and the motor torque can be regarded as parameters that can change the degree of contribution of the heat source to the temperature change of the oil FL.

  For example, in the vehicle V, the driving force (rotational speed) is not cut off between the rotating shaft 3 of the motor 21 and the wheel W, so the motor rotational speed is proportional to the vehicle speed of the vehicle V. The speed of the traveling wind varies depending on the motor rotation speed. Therefore, when the motor speed changes, the amount of heat transferred from the surface of the cylinder block of the engine 20 to the housing 2 of the motor 21 via the running wind changes. In this respect, the motor rotation speed can be regarded as a parameter that can change the degree of contribution of the engine 20 (heat source) to the temperature change of the oil FL.

  Further, for example, since the motor torque corresponds to the work amount of the motor 21, the amount of heat generated in the motor 21 changes according to the absolute value of the motor torque. As the motor torque (absolute value) increases and more heat is generated in the motor 21, the temperature gradient between the motor 21 and the oil FL increases. In this respect, the motor torque can be regarded as a parameter that changes the contribution of the motor 21 (heat source) to the temperature change of the oil FL. The absolute value of the motor torque is the magnitude of power input from the inverter 25 or the magnitude of power output to the inverter 25.

  For the various parameters described above, the ECU 10 calculates respective time average values of the engine temperature, the motor temperature, the motor rotation speed, the motor torque, and the outside air temperature. The time average value may be, for example, an integrated average value based on an integrated value of constant time of each of the engine temperature, the motor temperature, the motor rotation number, the motor torque, and the outside air temperature. The time average value may be a moving average value for a certain period of time of each of the engine temperature, the motor temperature, the motor rotation speed, the motor torque, and the outside air temperature.

  The fixed time may be determined based on respective time constants of the engine temperature, the motor temperature, the outside air temperature, the motor rotation speed, and the motor torque. The time constants of the motor rotational speed and the motor torque (parameter relating to the traveling state of the vehicle V) may be shorter than the time constants of the engine temperature, the motor temperature, and the outside air temperature (temperature parameter representing temperature). In such a case, the fixed time can be set, for example, to 3 minutes to 5 minutes so that the temperature change of the oil FL based on the motor rotational speed and the motor torque does not become sensitive. The fixed time is 5 minutes as an example.

The ECU 10 estimates the temperature of the oil FL, using each of the calculated time average values as an input of the estimation formula. The ECU 10 uses, as an estimation formula, the temperature of the refrigerant by a polynomial composed of a sum of a plurality of terms including at least k ₁ × T ₁ , k ₂ × T ₂ , k ₃ × N, k ₄ × TQ, and k ₅ × T _3. Estimate _TFL . As an example, the ECU 10 estimates the temperature T _{FL of the} oil FL by a polynomial expressed by the following expression (1) as an estimation expression.

T _FL = k ₁ × T ₁ + k ₂ × T ₂ + k ₃ × N + k ₄ × TQ + k ₅ × T ₃ + C (1)
However,
T ₁ : Time average value of motor temperature
T ₂ : Time average value of engine temperature
T ₃ : Time average value of outside air temperature
N: Time average value of motor rotational speed
TQ: Time average value of absolute value of motor torque
k ₁ , k ₂ , k ₃ , k ₄ , k ₅ : predetermined coefficients
C: predetermined constant

In the above equation (1), k ₁ is a weighting factor for T ₁ (time average value of motor temperature). k ₂ is a weighting factor for T ₂ (time average value of engine temperature). k ₃ is the weighting coefficient for N (time-averaged value of the motor speed). k ₄ is a weighting factor for TQ (time average value of absolute value of motor torque). k ₅ is a weighting factor for T ₃ (time average value of the outside air temperature). k ₁ , k ₂ , k ₃ , k ₄ , k ₅ , and C can be obtained, for example, by a technique such as a multiple regression analysis using the temperature of the oil FL measured by performing an actual vehicle test using the vehicle V. .

Further, in the vehicle V, the engine 20 and the motor 21 are arranged along the front-rear direction of the vehicle V in the vehicle V, and the motor 21 is arranged behind the vehicle V (that is, downstream of the traveling wind) from the engine 20. ing. Therefore, in the vehicle V, the influence of traveling wind on the transfer of heat from the surface of the cylinder block of the engine 20 to the housing 2 of the motor 21 is particularly significant. In this case, in the above equation (1), in the coefficients of T ₁ , T ₂ , N, TQ, and T ₃ , the weights are in the order of k ₁ , k ₂ , k ₃ , k ₄ , k ₅ . It becomes smaller and smaller. That is, k ₁ , k ₂ , k ₃ , k ₄ , and k ₅ satisfy the following equation (2). As an example, the ratio between k ₁ and k ₂ may be in the range of 2> k ₁ / k ₂ > 1.
k ₁ > k ₂ > k ₃ > k ₄ > k ₅ (2)

  Incidentally, the ECU 10 may limit the output of the motor 21 based on the temperature of the oil FL estimated as described above. Thereby, compared with the case where the output of the motor 21 is not limited, it can be suppressed that the temperature of the oil FL becomes excessively high. As a result, deterioration of the oil FL due to overheating is suppressed, and demagnetization of the permanent magnet 4b of the motor 21 is suppressed.

[Calculation processing of ECU 10]
Next, an example of the arithmetic processing by the refrigerant temperature estimation device 1 will be described with reference to FIG. The process of the flowchart shown in FIG. 5 is repeatedly performed, for example, while the vehicle V is traveling.

  As shown in FIG. 5, the ECU 10 of the refrigerant temperature estimation device 1 acquires the intake air temperature by the intake air temperature sensor 13 in S1. The ECU 10 acquires the water temperature by the water temperature sensor 12 in S2. In S <b> 3, the ECU 10 acquires the motor temperature by the motor temperature sensor 11.

  The ECU 10 acquires the motor rotational speed by the motor rotational speed sensor 14 in S4. The ECU 10 acquires the motor torque (raw value) calculated by the inverter 25 in S5. In S5, the ECU 10 acquires an absolute value of the motor torque from the acquired motor torque (raw value). In addition, the order of the process of S1-S5 may mutually be replaced.

In S6, the ECU 10 calculates the time average value of each of the engine temperature, the motor temperature, the motor rotation number, the motor torque, and the outside air temperature for each predetermined cycle (for example, a predetermined time for calculation of the time average value). In S7, the ECU 10 estimates the temperature of the oil FL for each predetermined period using each of the calculated time average values as an input of the estimation formula. The ECU 10 estimates the temperature T _{FL of the} oil FL according to a polynomial represented by the above equation (1) as an estimation equation. Thereafter, the ECU 10 ends the process of FIG.

[Action and effect]
As described above, as a result of intensive studies, the present inventors have determined that the temperature of the motor 21 (motor temperature) and the temperature of the engine 20 (engine temperature) are the controlling factors of the oil FL temperature of the motor 21 based on the experimental data. Further, the inventors have obtained knowledge that the temperature of the oil FL of the motor 21 can be estimated on the basis of an estimation expression that receives parameters related to the outside air temperature and the running state of the vehicle V. The inventor has also found that it is preferable that the parameters relating to the running state of the vehicle V include the motor rotation speed and the motor torque.

  Therefore, according to the refrigerant temperature estimation device 1, the ECU 10 generates the motor 21 based on the above equation (1), which is an estimation formula using the motor temperature, the engine temperature, the outside air temperature, the motor rotational speed and the motor torque as inputs. The temperature of the oil FL is estimated. Therefore, it is possible to estimate the temperature of the oil FL of the motor 21 (refrigerant temperature) without using the refrigerant temperature sensor by using the above knowledge.

  In the refrigerant temperature estimation device 1, the ECU 10 calculates time average values of the motor temperature, the engine temperature, the outside air temperature, the motor rotation speed, and the motor torque, and the calculated time average value is the above formula (1). The temperature of the oil FL is estimated. Thus, even if, for example, the motor rotational speed and the time constant of the motor torque are shorter than the time constants of the motor temperature, the engine temperature, and the outside air temperature, the temperature of the oil FL of the motor 21 can be estimated appropriately. It becomes.

  According to the experiment using the refrigerant temperature estimation device 1, the average value of the error between the temperature of the oil FL estimated by the refrigerant temperature estimation device 1 and the temperature of the oil FL actually measured for the experiment is about 2 ° C. The result can be obtained. The preferable condition may be, for example, a condition in which the engine 20 is sufficiently warmed up and the vehicle V is traveling at a certain vehicle speed or higher.

  In addition, according to the refrigerant | coolant temperature estimation apparatus 1, while the cost of a refrigerant | coolant temperature sensor is saved compared with the case where a refrigerant | coolant temperature sensor is used, for example, the risk by failure of a refrigerant | coolant temperature sensor is reduced.

[Modification]
As mentioned above, although embodiment concerning this invention was described, this invention is not limited to the said embodiment.

  For example, the first acquisition unit for acquiring the temperature of the motor 21 is not limited to the motor temperature sensor 11, and may be another detector, or may be acquired by estimating the temperature of the motor 21 by a known calculation You may do. The second acquisition unit for acquiring the temperature of the engine 20 is not limited to the water temperature sensor 12 and may be another detector, or may be acquired by estimating the temperature of the engine 20 by a known calculation There may be. The third acquisition unit that acquires the outside air temperature is not limited to the intake air temperature sensor 13, but may be another detector, or may be obtained by estimating the outside air temperature by a known calculation. Good.

The ECU 10 may estimate the temperature of the oil FL of the motor 21 based on an estimation formula different from the formula (1). For example, the parameter regarding the traveling state of the vehicle V is not limited to the form using both motor rotation speed and motor torque. The parameter related to the traveling state of the vehicle may be any one of the motor rotational speed and the motor torque, or may be a parameter other than the motor rotational speed and the motor torque. For example, as a parameter related to the traveling state of the vehicle V, an engine rotational speed, which is the rotational speed of the output shaft of the engine 20, a gear of the AMT 22, a motor torque (raw value) or the like may be used. When the engine speed is used as a parameter related to the traveling state of the vehicle V, for example, the engine speed when the clutch 23 is connected may be used instead of the motor speed, or the clutch 23 is separated. The engine speed of the case may be used. In addition, in the case where the arrangement of the engine 20 and the motor 21 is different in the vehicle V, k ₁ , k ₂ , k ₃ , k ₄ and k ₅ in the above equation (1) are The relationship 2) may not necessarily be satisfied.

  The ECU 10 calculates the time average value of each of the engine temperature, the motor temperature, the motor rotation number, the motor torque, and the outside air temperature, but the time average value may not necessarily be calculated. For example, the difference between the time constant of parameters relating to the traveling state of the vehicle V and the time constant of the engine temperature, the motor temperature, and the outside air temperature (temperature parameter representing temperature) is significant in the influence on the estimation of the temperature of the oil FL. If not, the ECU 10 does not calculate the time average value of each parameter, and estimates the temperature of the oil FL by using each parameter as it is (as a “raw value”) as an input of the estimation formula. Good.

  Although the oil FL is exemplified as the refrigerant of the motor 21, the refrigerant of the motor 21 is not limited to the oil FL. Moreover, although the motor 21 is an oil cooling type, the cooling system of the motor 21 is not limited to this. The oil FL may not be scooped up by the pressing plate 4 d rotating with the rotor 4.

Under conditions where the traveling wind of the vehicle V is weak, the ECU 10 may change the content of the temperature estimation of the oil FL, or may interrupt the estimation. As conditions under which the traveling wind of the vehicle V is weak, for example, the vehicle V is stopped, the vehicle V is traveling at low speed, the engine 20 is stopped, the engine 20 is idling, and the like. As a change in the content of the estimation of the temperature of the oil FL, the ECU 10 changes the coefficients and constants (k ₁ , k ₂ , k ₃ , k ₄ , k ₅ , and C) under the condition that the traveling wind of the vehicle V is weak. You may

  The ECU 10 may execute the estimation of the temperature of the oil FL under the condition that the temperature of the oil FL of the motor 21 can be increased. As conditions which the temperature of oil FL of the motor 21 may become high, when engine temperature is more than a predetermined | prescribed engine temperature threshold value, when outside temperature is more than a predetermined | prescribed outside temperature threshold value etc. are mentioned, for example. The engine temperature threshold may be 80 ° C., for example. The outside air temperature threshold may be 20 ° C., for example. In this case, the deterioration of the oil FL due to overheating can be effectively suppressed.

Although the ECU 10 estimates the temperature T _{FL of the} oil FL by the polynomial represented by the equation (1) described above as the estimation equation, the present invention is not limited to this. As an estimation formula, any polynomial can be used as long as it is a sum of a plurality of terms including at least k ₁ × T ₁ , k ₂ × T ₂ , k ₃ × N, k ₄ × TQ, and k ₅ × T ₃ . A term may be added. Other terms include, for example, a temperature parameter representing temperature, a temperature parameter related to a heat source that causes a temperature change of the oil FL directly or indirectly in the vehicle V, a parameter related to the running state of the vehicle V, and a temperature change of the oil FL. It may be a term including at least one of a parameter that can directly contribute, and a parameter that can change the degree of contribution of the heat source to the temperature change of the oil FL. These parameters may be multiplied by a predetermined coefficient.

  Reference Signs List 1: refrigerant temperature estimation device 10: ECU (estimation unit) 11: motor temperature sensor (first acquisition unit) 12: water temperature sensor (second acquisition unit) 13: intake air temperature sensor (third acquisition unit) 14 Motor rotational speed sensor (fourth acquisition unit) 20 engine (internal combustion engine) 21 motor (motor generator) 25 inverter (fourth acquisition unit) FL oil (refrigerant) V vehicle .

Claims (4)

A refrigerant temperature estimation device for estimating a temperature of a refrigerant of the motor generator in a vehicle including an internal combustion engine and a motor generator,
A first acquisition unit for acquiring the temperature of the motor generator;
A second acquisition unit for acquiring the temperature of the internal combustion engine;
A third acquisition unit for acquiring the outside air temperature;
A fourth acquisition unit for acquiring a parameter relating to the running state of the vehicle;
An estimation unit configured to estimate the temperature of the refrigerant of the motor generator based on an estimation formula using the temperature of the motor generator, the temperature of the internal combustion engine, the outside air temperature, and the parameter as inputs;
A refrigerant temperature estimation device comprising:   The estimation unit calculates a time average value of each of the temperature of the motor generator, the temperature of the internal combustion engine, the outside air temperature, and the parameter, and uses the calculated time average value as an input of the estimation formula. The refrigerant temperature estimation device according to claim 1, wherein the temperature of the refrigerant is estimated.   The refrigerant temperature estimation apparatus according to claim 1, wherein the parameter includes a rotation speed of the motor generator and a torque of the motor generator. The estimation unit uses a polynomial composed of a sum of a plurality of terms including at least k ₁ × T ₁ , k ₂ × T ₂ , k ₃ × N, k ₄ × TQ, and k ₅ × T ₃ as the estimation formula. The refrigerant temperature estimation device according to claim 3, wherein the refrigerant temperature is estimated.
However,
T ₁ : Time average value of the temperature of the motor generator
T ₂ : Time average value of the temperature of the internal combustion engine
T ₃ : Time average value of the outside air temperature
N: Time average value of the rotational speed of the motor generator
TQ: time average value of absolute value of torque of the motor generator
k ₁ , k ₂ , k ₃ , k ₄ , k ₅ : predetermined coefficients

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