JP6471192B2 - Temperature estimation system for cable members - Google Patents

Description

  According to the present invention, in a configuration in which a first device is connected to a first part of a cable member through which a current flows and a second device is connected to a second part of the cable member, the first part temperature of the first part The temperature estimation system of the cable member which estimates the 2nd site | part temperature of the said 2nd site | part based on this.

  Conventionally, for example, as shown in FIG. 1 of Patent Document 1, an electric motor (motor generator 18) that constitutes a drive source of a vehicle together with an engine (16), and a power control unit (inverter 20) that controls electric power of the electric motor. Are electrically connected by a cable member (an assembly of the high-voltage cable 30) ([0031], [0036] of Patent Document 1).

  In this specification, the cable member includes, in addition to the cable, a connector (terminal) that electrically connects one part of the cable to the phase wiring of the electric motor, and the cable to the phase wiring of the power control unit. Electrical connection means such as a connector (terminal) for electrically connecting the other part of the connector is included.

  The cable includes a conductor core wire and a covering portion of an insulating member that protects the core wire from a short circuit or the like.

  When a current flows through the cable core constituting the cable member, the cable core and the connector generate heat. If the amount of heat generation exceeds the allowable limit, the cable covering portion loses its insulating function. Therefore, it is necessary to use the cable member within an allowable temperature range.

JP 2012-244789 A

  Patent Document 1 discloses a technique for estimating the ambient temperature of a cable from an engine temperature, an outside air temperature, a cable current value, and a vehicle speed ([0042] of Patent Document 1).

  As described above, in Patent Literature 1, when the ambient temperature of the cable is estimated, the temperature and parameters closely related to the ambient temperature of the cable such as the engine temperature, the outside air temperature, and the cable current value are estimated.

  By the way, when estimating the temperature of the cable member, when the temperature of one part of the cable member is detected by the temperature sensor and the temperature of the other part is difficult to detect by the temperature sensor, the other part Patent Document 1 does not disclose a method for estimating the temperature.

  The present invention has been made in consideration of such a problem, and in the case where the temperature of one part of the cable member is acquired by a temperature sensor or the like, it is dedicated for detecting the temperature of the other part of the cable member. An object of the present invention is to provide a temperature estimation system for a cable member that makes it possible to estimate the temperature of the other part with a simple configuration without providing the temperature sensor.

The temperature estimation system for a cable member according to the present invention is:
A cable member electrically connecting the first device and the second device by connecting the first part to the first device and connecting the second part to the second device;
First part temperature acquisition means for acquiring a part temperature of the first part;
First part ambient temperature acquisition means for acquiring the ambient temperature of the first part;
Second part ambient temperature acquisition means for acquiring the ambient temperature of the second part;
A second part temperature estimation unit for estimating a part temperature of the second part,
The second part temperature estimator is
Calculating a temperature increase parameter of the first part based on the acquired part temperature of the first part and the ambient temperature of the first part;
Based on the temperature increase parameter of the first part and the acquired ambient temperature of the second part, the part temperature of the second part is estimated.

  According to this invention, when the temperature of one part of the cable member is acquired, the temperature of the other part of the cable member, which is a part where it is difficult to directly detect the temperature, is used as a dedicated temperature sensor. It is possible to estimate with a simple configuration without providing.

  That is, the characteristic (knowledge) that the temperature rise degree by each heat generating part of the part temperature and the ambient temperature of the first part of the cable member and the part temperature and the ambient temperature of the second part of the cable member are substantially equal. In consideration of the temperature of the second part of the cable member, for which it is difficult to directly acquire the temperature, the temperature can be easily estimated from the part temperature and the ambient temperature of the first part that can be obtained and the ambient temperature of the second part that can be obtained. Can do.

  Thus, according to the present invention, the temperature of the second part of the cable member is based on the ambient temperature of the second part and the temperature increase parameter of the first part located at a position away from the second part. Can be estimated.

  By this invention, the temperature estimation method of the site | part temperature of the cable member in the specific structure which connected two devices (1st and 2nd device) with one cable member was able to be established.

In this case, the second part temperature estimation unit is
Further, the first parameter that affects the heat conduction from the first part to the surroundings and the second parameter that affects the heat conduction from the second part to the surroundings are obtained, and the obtained first and The temperature of the second part may be estimated based on the second parameter.

  The temperature rise values of the first part and the second part of the cable member are determined by self-heating and heat conduction (heat radiation) to the surroundings. Therefore, the temperature of the second part is accurately obtained by reflecting the difference in heat conduction due to the difference in the surrounding environment between the first part and the second part using the first and second parameters that can be obtained by the sensor or the like. The accuracy of temperature estimation can be improved.

Here, the cable member is mounted on a vehicle,
The periphery of the first part is air, and the periphery of the second part is liquid,
The first parameter is a vehicle speed of the vehicle;
The second parameter may be a flow rate of the liquid around the second part or a physical quantity correlated with the flow rate.

  Thus, by using the physical quantity such as the vehicle speed of the vehicle and the flow velocity of the liquid around the second part, the influence of air and liquid in the vehicle can be accurately reflected.

The first device is a power control unit that controls electric power supplied from the in-vehicle capacitor to the electric motor,
The second device is the electric motor;
The cable member is a high voltage cable that supplies power from the power control unit to the electric motor,
The second portion of the cable member may be an electrical connection portion between a cable and the electric motor, and the liquid may be a lubricating oil that lubricates the electric motor.

  According to this configuration, it is possible to accurately estimate the temperature of the electrical connection portion between the cable and the motor, for which it is difficult to measure the temperature.

  According to the present invention, when the temperature of one part of the cable member is acquired by a temperature sensor or the like, the configuration can be simplified without providing a dedicated temperature sensor for detecting the temperature of the other part of the cable member. The temperature of the other part can be estimated.

It is a top view which shows schematic structure of the vehicle by which the temperature estimation system of the cable member which concerns on this embodiment is mounted. It is a principal part block diagram of the temperature estimation system of the said cable member. It is a schematic sectional drawing of the mounting state of the connector of a cable member. It is an actual measurement characteristic figure which shows the change of the connector temperature etc. with respect to a vehicle speed. It is a flowchart provided for description of the estimation method of a connector temperature. It is a map for acquiring the correction coefficient which corrects a temperature difference. It is a characteristic view with which it uses for description of the modification for calculating | requiring the ambient temperature by the side of a motor.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a temperature estimation system for a cable member according to the present invention will be described in detail with reference to the accompanying drawings.

[Constitution]
FIG. 1 is a plan view showing a schematic configuration of a vehicle 20 on which a cable member temperature estimation system 10 according to this embodiment is mounted.

  FIG. 2 is a configuration diagram of a main part of the temperature estimation system 10 for the cable member.

  The vehicle 20 is a hybrid vehicle, and includes a front wheel drive motor (motor / MOT) 12 and an engine (ENG) 14 disposed in the front hood, and a rear wheel drive motor disposed coaxially with the rear axle. (Motor / MOT) 16 and 18.

  The motors 12, 16, and 18 are driven and controlled by a power control unit (PCU) 22.

  The PCU 22 disposed under the passenger compartment includes a power drive unit (PDU) 24 that is an inverter and an ECU (Electronic Control Unit) 30 that is a controller. The ECU 30 includes a CPU and a memory, and functions as various functional units when the CPU reads and executes a program stored in the memory.

  High voltage DC power is supplied to the PDU 24 from a battery (BAT) 32.

  The PCU 22 (PDU 24) and the motors 12, 16, and 18 are electrically connected via cable members 42, 46, and 48, respectively.

  The cable member 42 will be described as a representative. The cable member 42 includes a high voltage cable (cable) 50 and connectors 51 and 52 provided at both ends of the high voltage cable 50.

  The detachable connectors 51 and 52 are attached to connectors provided on the PDU 24 side and the motor 12 side, respectively.

  FIG. 3 is a schematic cross-sectional view of the connector 52 in a mounted state. The cross section of the remaining connector 51 and the cross sections of the cable members 46 and 48 have the same configuration.

  As shown in FIG. 3, the crimp terminal 56 is attached to the core wire of the high-voltage cable 50 that is insulated by the covering member 54, and the motor-side terminal 58 is inserted into the hole of the crimp terminal 56 to be electrically connected. Has been. Since contact resistance is generated in the crimping portion 60 of the crimp terminal 56, when a current is passed through the core wire of the cable member 42, the crimping portion 60 in the cable member 42, in other words, the connector 52 is the hottest. become. Similarly, the connector 51 becomes hot.

  As shown in FIG. 1, the motor 12 is provided with a circulation path 73 for lubricating oil 72 for cooling and lubricating a rotor, a bearing, and the like of the motor 12. Exchanged.

  The engine 14 is provided with a circulation path 75 of a radiator liquid 74 for cooling the engine 14, and the radiator liquid 74 is heat-exchanged with the outside air by the radiator 64.

  A motor pump (not shown) for circulating the lubricating oil 72 and the radiator liquid 74 is inserted into the circulation paths 73 and 75, respectively.

  In accordance with the rotation speed (pump rotation speed) Np of a motor pump 78 (see FIG. 2) as an oil pump for circulating the lubricating oil 72, the ECU 30 causes the average flow velocity (referred to as the flow velocity Vf) of the lubricating oil 72 in the circulation path 73. Can be requested. Note that the flow velocity Vf, which is a physical quantity, may be obtained from the flow rate of the lubricating oil 72 that circulates in the circulation path 73 (the flow rate is also a physical quantity) in addition to the rotational speed Np, which is a physical quantity.

  In addition to the pump speed Np for obtaining the flow velocity Vf of the lubricating oil 72 and the vehicle speed Vv by the vehicle speed sensor 80, the ambient temperature Ta of the connector 51 detected by the ambient temperature sensor 91, the connector temperature Tc1 detected by the connector temperature sensor 81 The oil temperature Tf detected by the oil temperature sensor (lubricating oil temperature sensor) 92 is taken into the ECU 30.

  The ambient temperature sensor 91 is provided in the PCU 22 (the PDU 24) and detects the temperature of the air in the vicinity of the connector 51, and when the vehicle 20 is traveling, the PCU 22 detects the vehicle speed Vv. It is air-cooled by the air flow according to

  The connector temperature sensor 81 is provided at the terminal of the connector 51 on the PCU 22 side and detects the temperature of the terminal as the connector temperature Tc1.

  The lubricating oil temperature sensor 92 detects the oil temperature Tf, which is the temperature of the lubricating oil 72 in the oil pan in the motor 12, as the ambient temperature of the motor 12.

[Operation]
Next, the operation of the cable member temperature estimation system 10 according to the above-described embodiment will be described in detail.

  In this embodiment, the ECU 30 is detected by the connector temperature Tc1 detected by the connector temperature sensor 81 on the PCU 22 side, the ambient temperature Ta detected by the ambient temperature sensor 91 on the PCU 22 side, and the oil temperature sensor 92 on the motor 12 side. Based on the oil temperature Tf, the connector temperature Tc2 of the connector 52 on the motor 12 side (temperature of the caulking portion 60) is estimated.

  First, the temperature estimation principle will be described.

(1) Description of temperature estimation principle FIG. 4 shows the temperature characteristic 101 of the connector temperature Tc1 of the connector 51, the temperature characteristic 202 of the connector temperature Tc2 of the connector 52, the temperature characteristic 212 of the oil temperature Tf, and the connector with respect to the vehicle speed Vv. It is the characteristic view which measured the temperature characteristic 111 of 51 ambient temperature (connector ambient temperature) Ta.

  It can be understood from FIG. 4 that each temperature Tc1, Tc2, Tf, Ta decreases as the vehicle speed Vv increases.

  It can also be seen that the shape of the characteristics of the temperature characteristic 202 of the connector temperature Tc2 on the motor 12 side and the temperature characteristic 212 of the oil temperature Tf of the lubricating oil 72 that cools the motor 12, etc., indicated by solid lines, are approximate.

  Furthermore, it can be seen that the temperature characteristics 101 of the connector temperature Tc1 on the PCU 22 side and the temperature characteristics 111 of the ambient temperature Ta inside the PCU 22 shown by broken lines are similar in characteristic shape.

  Therefore, the temperature characteristic 101 of the connector temperature Tc1 on the PCU 22 side with respect to the temperature characteristic 111 of the ambient temperature Ta in the PCU 22 and the connector temperature Tc2 on the motor 12 side with respect to the temperature characteristic 212 of the oil temperature Tf of the lubricating oil 72 that cools the motor 12 or the like. It is estimated that each of the temperature characteristics 202 has a high correlation.

  Here, in the vehicle 20, the ambient temperature Ta in the PCU 22 and the connector temperature Tc1 on the PCU 22 side can be detected by the connector temperature sensor 81 and the ambient temperature sensor 91, respectively. The oil temperature Tf on the motor 12 side can be detected by the oil temperature sensor 92. On the other hand, the connector temperature Tc2 on the motor 12 side is unknown because it is difficult to detect and is unknown.

  Therefore, the correlation between the known ambient temperature Ta (temperature characteristic 111) in the PCU 22 and the connector temperature Tc1 (temperature characteristic 101) on the PCU 22 side is expressed by the known oil temperature Tf on the motor 12 side and the unknown connector on the motor 12 side. The unknown connector temperature Tc2 is calculated by applying to the relationship with the temperature Tc2.

(2) Description of Temperature Estimation Process (Temperature Estimation Method) An estimation method (calculation method) of the unknown connector temperature Tc2 on the motor 12 side will be described with reference to the flowchart of FIG. Note that the execution subject of the program according to the flowchart is the ECU 30. The flowchart is executed when the ignition of the vehicle 20 is ON.

  In step S1, connector temperature Tc1 and ambient temperature Ta of connector 51 on PCU 22 side are detected from connector temperature sensor 81 and ambient temperature sensor 91.

In step S2, a temperature difference ΔT1 between the connector temperature Tc1 on the PCU 22 side and the ambient temperature Ta is obtained by the following equation (1).
ΔT1 = Tc1-Ta (1)

Next, in step S3, the temperature difference ΔT1 on the PCU 22 side is multiplied by the correction coefficient K1 to obtain the following equation (2). The temperature difference ΔT1 on the PCU 22 side is corrected (applied) to the temperature difference ΔT2 between the connector temperature Tc2 of the connector 52 on the motor 12 side and the oil temperature Tf.
ΔT2 = K × ΔT1 = K × (Tc1-Ta) (2)

  FIG. 6 shows a correction coefficient map (correction coefficient characteristic) 250 for obtaining the correction coefficient K of equation (2).

  The correction coefficient K is obtained from the vehicle speed Vv and the flow velocity Vf, and the value of the correction coefficient K decreases as the vehicle speed Vv increases and the flow velocity Vf increases. The correction coefficient K takes a value between 0.8 and 1.1, but a value in between may be obtained by interpolation processing. Note that the flow velocity Vf may be replaced with a flow rate correlated with the flow velocity Vf or the pump rotation speed Np.

  Therefore, in step S3, the vehicle speed sensor 80 detects the vehicle speed Vv, detects the rotational speed Np of the motor pump 78, calculates the flow velocity Vf, and refers to the correction coefficient map 250 shown in FIG. And a temperature difference ΔT2 between the connector temperature Tc2 of the connector 52 on the motor 12 side and the oil temperature Tf is obtained from the equation (2).

Finally, in step S4, the oil temperature Tf is detected, and the connector temperature Tc2 on the motor 12 side is estimated (calculated) by adding the temperature difference ΔT2 to the detected oil temperature Tf as shown in the following equation (3). )
Tc2 = Tf + ΔT2 (3)

[Summary]
As described above, in the cable member temperature estimation system 10 according to the above-described embodiment, the connector 51 as the first part is connected to the PCU 22 (the PDU 24) as the first device (first heat generating device), By connecting the connector 52 as the second part to the motor 12 as the two devices (second heat generating device), the PCU 22 (the PDU 24) as the first device and the motor 12 as the second device are electrically connected. Connector member 81 as a first part temperature acquisition means (first part temperature sensor) for acquiring (detecting) a connector temperature Tc1 as a part temperature of the cable member 42 and the connector 51 as the first part. And first part ambient temperature acquisition means for acquiring (detecting) the ambient temperature Ta of the connector 51 as the first part ( A second part ambient temperature acquisition means (second part ambient temperature acquisition means) that acquires (detects) an ambient temperature sensor 91 as one part ambient temperature sensor) and an oil temperature Tf that is regarded as the ambient temperature of the connector 52 as the second part. A lubricating oil temperature sensor 92 as a temperature sensor) and an ECU 30 as a second part temperature estimating unit for estimating a connector temperature Tc2 as a part temperature of the connector 52 as the second part.

  In this case, the ECU 30 serving as the second part temperature estimation unit is configured based on the acquired (detected) connector temperature Tc1 that is the part temperature of the connector 51 serving as the first part and the ambient temperature Ta of the first part. A temperature difference ΔT1 (ΔT1 = Tc1−Ta) as a temperature increase parameter of the first part is calculated (step S2), and the temperature difference ΔT1 as the temperature increase parameter of the first part and the acquired (detected) second value. Based on the oil temperature Tf regarded as the ambient temperature of the connector 52 as a part, the connector temperature Tc2 that is the part temperature of the connector 52 as the second part is estimated (step S4).

  According to this embodiment, the temperature (connector temperature Tc1) of one part of the cable member 42 (in the above embodiment, the first connector 51) is acquired (detected) by the temperature sensor (connector temperature sensor 81). In addition, the temperature (connector temperature Tc2) of the other part (second connector 52) of the cable member 42, which is a part where it is difficult to directly detect the temperature, can be simplified without providing a dedicated temperature sensor such as a thermistor. It can be estimated by configuration.

  That is, the ambient temperature Ta of the first part (first connector 51) to which heat is transmitted from the first part (first connector 51) whose temperature rises by the PCU 22 as the first heat generating device, and the second heat generating device The ambient temperature of the second part (second connector 52) to which the heat from the second part (second connector 52) whose temperature rises by the motor 12 is transmitted (the oil temperature Tf of the lubricating oil 72 of the motor 12 considered as the ambient temperature). ) And the characteristic (knowledge) that the degree of temperature increase due to each heat generation is substantially equal, the temperature of the second part (second connector 52) of the cable member 42 where it is difficult to obtain the temperature directly (Second connector temperature Tc2) is simply estimated.

  That is, according to this embodiment, the temperature of the second portion (second connector 52) of the cable member 42 (second connector temperature Tc2) is used as the ambient temperature of the second portion (second connector 52). It can be estimated based on the temperature Tf and the temperature difference ΔT1 as a temperature increase parameter of the first part (first connector 51) located at a position away from the second part (second connector 52).

  As described above, according to this embodiment, the cable member 42 in a specific configuration in which two heat generating devices (the PCU 22 and the motor 12 as the first and second heat generating devices) are connected by the one cable member 42 is used. The temperature estimation method of the part temperature was established.

  Even if a dedicated temperature sensor such as the thermistor can be provided at the other part (second connector 52) of the cable member 42, the signal line of the temperature sensor is connected from the electric motor 12 in the front hood to the vehicle compartment. Wiring up to the PCU 22 is not preferable because the wiring length becomes long and the number of assembling steps increases. That is, the other part (second connector 52) of the cable member 42 is a part where it is difficult to measure the temperature.

  In this case, the ECU 30 as the second part temperature estimation unit further includes a vehicle speed Vv as a first parameter that affects heat conduction from the first part (first connector 51) to the surroundings, and the second part. The flow velocity Vf as a second parameter that affects the heat conduction from the (second connector 52) to the surroundings is acquired, and the temperature rise is based on the acquired first and second parameters (vehicle speed Vv and flow velocity Vf). Based on the temperature difference ΔT2 {ΔT2 = K × (Tc1-Ta)} obtained by correcting the temperature difference ΔT1 as a parameter, the temperature (connector temperature Tc2) of the second part (second connector 52) is estimated (step S4).

  According to this embodiment, the second part (second connector 52) is reflected by reflecting the difference in heat conduction due to the difference in the surrounding environment of the first part (first connector 51) and the second part (second connector 52). ) (Connector temperature Tc2) can be obtained with high accuracy, and the accuracy of temperature estimation is improved.

  In the above-described embodiment, the cable member 42 is mounted on the vehicle 20, and the periphery of the first part (first connector 51) is air (gas refrigerant) and the periphery of the second part (second connector 52). Is the liquid (liquid refrigerant), the first parameter is the vehicle speed Vv, and the second parameter is the flow velocity Vf of the liquid (lubricating oil 72) around the second part (second connector 52).

  Thus, by using the vehicle speed Vv of the vehicle 20 and the flow velocity Vf of the liquid (lubricating oil 72) around the second portion (second connector 52), the influence of air and liquid in the vehicle 20 can be accurately reflected. .

  More specifically, in the above-described embodiment, the first heat generating device is a PCU 22 that controls electric power supplied from the battery 32 as the on-vehicle capacitor to the motor 12 as the electric motor, and the second heat generating device is the electric motor. The cable member 42 is a high-voltage cable 50 that supplies power from the PCU 22 to the motor 12, and the second part of the cable member 42 is formed between the high-voltage cable 50 and the motor 12. It is an electrical connection part (second connector 52), and the liquid is lubricating oil 72 that lubricates the motor 12.

  According to this embodiment, the temperature (connector temperature Tc2) of the electrical connection portion (second connector 52) between the high-voltage cable 50 and the motor 12 in the vehicle 20 can be accurately estimated.

[Modification]
In the vehicle 20 according to this embodiment, since the motor 12 and the engine 14 are integrated, the ambient temperature of the connector 52 can be seen from the characteristic 252 of the radiator liquid 74 with respect to the ambient temperature Ta2 shown in FIG. Ta2 can be uniquely obtained from the liquid temperature Tw of the radiator liquid 74 and the oil temperature Tf of the lubricating oil 72 that lubricates and cools the motor 12.

  Further, the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification.

DESCRIPTION OF SYMBOLS 10 ... Cable member temperature estimation system 12, 16, 18 ... Electric motor (motor) 22 ... PCU
24 ... PDU 30 ... ECU
42, 46, 48 ... cable member 50 ... cable 51, 52 ... connector 81 ... connector temperature sensor 91 ... ambient temperature sensor 92 ... oil temperature sensor

Claims (4)

A cable member electrically connecting the first device and the second device by connecting the first part to the first device and connecting the second part to the second device;
First part temperature acquisition means for acquiring a part temperature of the first part;
First part ambient temperature acquisition means for acquiring the ambient temperature of the first part;
Second part ambient temperature acquisition means for acquiring the ambient temperature of the second part;
A second part temperature estimation unit for estimating a part temperature of the second part,
The second part temperature estimator is
Calculating a temperature increase parameter of the first part based on the acquired part temperature of the first part and the ambient temperature of the first part;
A temperature estimation system for a cable member, wherein the temperature of the second part is estimated based on the temperature increase parameter of the first part and the acquired ambient temperature of the second part. The temperature estimation system for a cable member according to claim 1,
The second part temperature estimator is
Further, the first parameter that affects the heat conduction from the first part to the surroundings and the second parameter that affects the heat conduction from the second part to the surroundings are obtained, and the obtained first and A temperature estimation system for a cable member, wherein the temperature of the second part is estimated based on a second parameter. In the temperature estimation system of the cable member according to claim 2,
The cable member is mounted on a vehicle,
The periphery of the first part is air, and the periphery of the second part is liquid,
The first parameter is a vehicle speed of the vehicle;
The cable member temperature estimation system, wherein the second parameter is a flow rate of the liquid around the second portion or a physical quantity correlated with the flow rate. In the temperature estimation system of the cable member according to claim 3,
The first device is a power control unit that controls electric power supplied from an in-vehicle capacitor to an electric motor,
The second device is the electric motor;
The cable member is a high voltage cable that supplies power from the power control unit to the electric motor,
The cable member temperature estimation system, wherein the second portion of the cable member is an electrical connection portion between the cable and the electric motor, and the liquid is a lubricating oil that lubricates the electric motor.

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