JP6183180B2 - Hybrid vehicle and control method thereof - Google Patents

Description

  The present invention relates to a hybrid vehicle and a control method therefor, and more particularly to a hybrid vehicle and a control method therefor that can cool high-power components in a hybrid system without degrading the running performance of the vehicle.

  In recent years, hybrid vehicles equipped with a hybrid system that replaces a part of the driving force generated by the engine with a motor generator that is supplied with electric power from a high-voltage battery through an inverter have attracted attention from the viewpoint of improving fuel efficiency and environmental measures. Has been.

  Since all of the batteries, inverters, and motor generators, which are high-power components in this hybrid system, generate heat during traveling, the hybrid vehicle is provided with a dedicated cooling system. Specifically, air cooling by an electric fan is generally performed for a battery, and water cooling using a cooling water circuit is generally performed for an inverter and a motor generator (see, for example, Patent Documents 1 and 2).

  Usually, in such a cooling system, when the body temperature of any of the battery, inverter and motor generator exceeds a preset threshold value, the battery and motor generator are protected in order to protect the parts. Control is performed to limit the torque of the motor generator by suppressing the current flowing between the motor and the machine.

  This threshold value is set to have a large margin with respect to the temperature limit for use specified for the part. Therefore, depending on the state of the cooling system, the torque is limited more than necessary, and the traveling performance of the hybrid vehicle may be reduced.

JP 2002-166728 A Japanese Patent Laid-Open No. 11-117744

  An object of the present invention is to provide a hybrid vehicle and a control method thereof that can cool high-power components in a hybrid system without degrading the running performance of the vehicle.

  The hybrid vehicle of the present invention that achieves the above object can replace at least a part of the driving force generated by the engine with the driving force of a motor generator driven by electric power supplied from a battery through an inverter, An electric fan that cools the battery, a water cooling device that cools the inverter and the motor generator with cooling water, three component temperature sensors that respectively measure the temperature of the battery, the inverter, and the motor generator, and a control means. And the control means is configured such that when a measured value of at least one of the three component temperature sensors exceeds a first threshold value preset for each of the battery, the inverter, and the motor generator. In a hybrid vehicle that performs control to limit the torque generated by the motor generator, cooling for measuring the temperature of the cooling water A temperature sensor and an outside air temperature sensor for measuring the outside air temperature of the hybrid vehicle are provided, and the control means is configured to reduce any of the measured values of the three component temperature sensors to the first threshold value or less corresponding to each of them. And the measured value of at least one of the cooling water temperature sensor and the outside air temperature sensor exceeds a second threshold value preset for each of the cooling water and the outside air temperature. In this case, the first threshold value is newly set based on a measured value exceeding the second threshold value and preset map data.

  In the hybrid vehicle control method of the present invention that achieves the above object, at least a part of the driving force generated by the engine can be replaced by the driving force of a motor generator driven by electric power supplied from a battery through an inverter. In the hybrid vehicle control method comprising an electric fan that cools the battery and a water cooling device that cools the inverter and the motor generator with cooling water, the temperature of the battery, the inverter, and the motor generator is preset. Each of the measured first threshold values, and when at least one of the three temperatures exceeds the corresponding first threshold value, the torque generated by the motor generator is limited while When all of the three measured values are not more than the first threshold value corresponding to each of the three measured values, When the outside temperature of the hybrid vehicle is compared with each preset second threshold value, and at least one of the two temperatures exceeds the corresponding second threshold value Each of the first threshold values is newly set based on a temperature exceeding the second threshold value and preset map data.

  According to the hybrid vehicle and the control method thereof of the present invention, the torque of the motor generator is adjusted according to the cooling performance of the electric fan and the water cooling device that cools the high-power components including the motor generator, the inverter, and the battery. Since the restriction is made, the high-power components can be cooled without deteriorating the running performance of the hybrid vehicle.

It is a block diagram of the hybrid vehicle which consists of embodiment of this invention. It is a side view of a hybrid vehicle. It is a flowchart explaining the control method of the hybrid vehicle which consists of the 1st Embodiment of this invention. It is a flowchart explaining the control method of the hybrid vehicle which consists of the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a hybrid vehicle according to a first embodiment of the present invention.

  A hybrid vehicle (hereinafter referred to as “HEV”) 1 is a truck that is a large vehicle, and is a diesel that is connected to an output shaft 3 that transmits a driving force to a pair of left and right drive wheels 2 and 2 via a transmission 4. A hybrid system 9 having an engine 5 and a motor generator 6 and a battery 8 electrically connected to the motor generator 6 through an inverter 7 is provided. Further, a wet multi-plate clutch 10 and a fluid coupling 11 are interposed between the transmission 4 and the diesel engine 5 in this order.

  The hybrid system 9 is not limited to the above-described configuration. For example, a configuration in which the diesel engine 5 and the motor generator 6 are connected in series, or the motor generator 6 is connected to the pair of drive wheels 2 and 2, respectively. A directly connected configuration may be used.

  The motor generator 6, the inverter 7, and the battery 8 correspond to the high-power component 12 of the hybrid system 9. As shown in FIG. 2, for example, the battery 8 and the inverter 7 among the high-power components 12 are disposed in a substantially rectangular parallelepiped unit box 14 that is disposed on the side of the lower surface of the vehicle body 13 of the HEV 1 and extends in the longitudinal direction of the vehicle body 13. It is stored.

  Since the high-voltage component 12 generates heat during traveling, the HEV 1 is equipped with a dedicated cooling system. Specifically, the battery 8 is air-cooled by the electric fan 15 installed in the unit box 14 toward the vehicle front side (traveling direction side). In addition, the motor generator 6 and the inverter 7 are cooled by a water cooling device 18 through which a cooling water 17 that circulates in turn in the radiator 16, the inverter 7 and the motor generator 6 installed in the unit box 14 toward the vehicle side. Is done. In this water cooling device 18, the cooling water 17 is sent out by a pump 19, and bubbles are removed from the catch tank 20.

  The ECU 21 that is a control means of the HEV 1 performs control for assisting the driving force of the diesel engine 5 by the motor generator 6 according to a load applied to the output shaft 3 when the HEV 1 travels. Further, surplus energy during normal driving of the HEV 1 and regenerative energy during braking are collected as electric power by using the motor generator 6 as a generator, and the battery 8 is charged through the inverter 7.

Further, ECU 21 includes an electric power generator 6, exceeds the inverter 7 and the component temperature sensor 22A which is mounted respectively to the battery 8, 22B, the first threshold value T ₁ at least one previously set out of a measured value of 22C In this case, the magnitude of the current flowing between the motor generator 6 and the battery 8 is suppressed using the inverter 7, and control for limiting the torque of the motor generator 6 is performed.

Examples of the first threshold value T ₁ include values in the range of 60 to 90 ° C. for the motor generator 6, 50 to 70 ° C. for the inverter 7, and 30 to 50 ° C. for the battery 8. .

  A cooling water temperature sensor 23 for measuring the temperature of the cooling water 17 is attached to the HEV 1 in the vicinity of the inlet of the radiator 16 in the water cooling device 18, and an outside air temperature sensor 24 for measuring the outside air temperature of the HEV 1 is provided. ing. These temperature sensors 23 and 24 are connected to the ECU 21 through signal lines (indicated by a one-dot chain line).

  A first control method related to the cooling of the high-power component 12 in the HEV 1 will be described below with reference to FIG.

ECU21 determines component temperature sensor 22A, 22B, 22C of the measurement value inputted (S10), whether the first threshold value T ₁ than that corresponding to each measured value (S20).

When at least one of the three measured values is greater than the corresponding first threshold value T ₁ , the magnitude of the current flowing between the motor generator 6 and the battery 8 through the inverter 7 is suppressed. Thus, the torque of the motor generator 6 is limited (S30).

On the other hand, when all of the three measured values are equal to or less than the first threshold value T ₁ corresponding to each of them, the measured values of the cooling water temperature sensor 23 and the outside air temperature sensor 24 are input (S40). ), It is determined whether or not each measured value exceeds a preset second threshold value T ₂ corresponding to the measured value (S50).

As for the second threshold value T ₂ , values in the range of 40 to 60 ° C. for the cooling water 17 and 30 to 40 ° C. for the outside air temperature are exemplified.

When at least one of the two measured values is greater than the corresponding second threshold value T ₂ , the measured value that is greater than the second threshold value T ₂ is set as map data set in advance. matching to (S60), after the respective first threshold value T ₁ of the newly set low (S70), the flow returns to step 10.

This map data is obtained by previously setting the correlation between the first threshold value T ₁ of each of the motor generator 6, the inverter 7 and the battery 8 and the temperature of the cooling water 17 or the outside air temperature by experiment or calculation. is there. In the map data, the first threshold value T ₁ of each component basically has a negative correlation with the temperature of the cooling water 17 and the outside air temperature.

On the other hand, when both of the two measured values are equal to or less than the second threshold value T ₂ corresponding to each of the two measured values, the process directly returns to step S10.

  By performing such control, the torque of the motor generator 6 can be limited according to the cooling performance margin of the electric fan 15 and the water cooling device 18 that cool the high-power components 12 in the hybrid system 9. Thus, the high-power component 12 can be cooled without degrading the running performance of the HEV 1.

Each newly set first threshold value T ₁ must not exceed the temperature limit for use (for example, 60 ° C.) defined for each high-power component 12. .

  A second control method relating to cooling of the high-power component 12 in the HEV 1 will be described below with reference to FIG. In addition, the same control number as FIG. 2 is attached | subjected to the same step number, and the description is abbreviate | omitted.

After performing the control of Steps 10 to 40, the ECU 21 further determines each measurement value when both of the two measurement values are equal to or smaller than the corresponding second threshold value T ₂ in Step 50. determines whether or not the third threshold T ₃ than the corresponding for (S80).

The third threshold value T ₃ is a value lower than the second threshold value T _{2 described} above. The cooling water 17 has a value in the range of 20 to 40 ° C., and the outside air temperature has a value in the range of 0 to 30 ° C. , Respectively.

When at least one of the two measured values exceeds the corresponding third threshold value T ₃ , the rate of increase in the measured values of the component temperature sensors 22A, 22B, and 22C input in step 10 is calculated. (S90), it determines whether the fourth threshold T ₄ than the corresponding for each increase rate (S100).

On the other hand, if both of the two measured values are equal to or less than the third threshold value T ₃ corresponding to each of the two measured values, the process directly returns to step S10.

The fourth threshold T ₄ described above are intended to show the rate of increase in the measured value in a predetermined period of time, 0.5 to 1.0 ° C. / sec for the motor generator 6, the inverter 7 0.5 The values in the range of -1.0 ° C / second and the battery 8 in the range of 0.5-1.0 ° C / second are exemplified.

When at least one of the calculated three increasing rates is greater than the corresponding fourth threshold value T ₄ , the magnitude of the current flowing between the motor generator 6 and the battery 8 through the inverter 7 is determined. By suppressing, the torque of the motor generator 6 is limited (S30). As a result, the increase rate of the corresponding high-power components 12 is reduced, so that the margin of cooling performance of the electric fan 15 and / or the water cooling device 18 is increased, while any of the three increase rates corresponds to each. to when the fourth is the threshold T ₄ or less, the process returns to step S10.

  By performing such control, the torque of the motor generator 6 can be limited according to the heating state of the high-power system parts 12 in addition to the margin of cooling performance of the electric fan 15 and the water cooling device 18. Thus, the high-power component 12 can be efficiently cooled without further degrading the running performance of the HEV 1.

1 HEV
5 Diesel Engine 6 Motor Generator 8 Battery 12 High Power System Parts 14 Radiator 15 Electric Fan 17 Cooling Water 18 Water Cooling Device 21 ECU
22A, 22B, 22C Component temperature sensor 23 Cooling water temperature sensor 24 Outside air temperature sensor

Claims (5)

At least a part of the driving force generated by the engine can be replaced by the driving force of a motor generator driven by electric power supplied from a battery through an inverter,
An electric fan that cools the battery, a water cooling device that cools the inverter and the motor generator with cooling water, three component temperature sensors that respectively measure temperatures of the battery, the inverter, and the motor generator, and control means; With
The control means, when the measured value of at least one of the three component temperature sensors exceeds a first threshold value preset for each of the battery, inverter and motor generator, In a hybrid vehicle that performs control to limit the torque generated by the motor generator,
A cooling water temperature sensor for measuring the temperature of the cooling water, and an outside air temperature sensor for measuring the outside air temperature of the hybrid vehicle,
The control means is a case where all measured values of the three component temperature sensors are equal to or less than the first threshold value corresponding to each of the three component temperature sensors, and among the cooling water temperature sensor and the outside air temperature sensor. If at least one of the measured values exceeds the second threshold value preset for each of the cooling water and the outside air temperature, the measured value exceeding the second threshold value is preset. Each of the first threshold values is newly set based on map data.   The control means is configured such that each of the measured values of the cooling water temperature sensor and the outside air temperature sensor is equal to or less than the second threshold value corresponding to each, and is set in advance for each of the cooling water and the outside air temperature. If the third threshold value is exceeded, the increase rate of the measured value of at least one of the three component temperature sensors is preset for each of the battery, the inverter, and the motor generator. The hybrid vehicle according to claim 1, wherein when the fourth threshold value is exceeded, control is performed to limit a torque generated by the motor generator.   The hybrid vehicle according to claim 1, wherein the hybrid vehicle is a large vehicle including a truck or a bus. At least part of the driving force generated by the engine can be replaced by the driving force of a motor generator driven by electric power supplied from a battery through an inverter, and the electric fan for cooling the battery, the inverter and the motor generator In a control method of a hybrid vehicle comprising a water cooling device for cooling a machine with cooling water,
Comparing the temperature of the battery, inverter and motor generator with a respective preset first threshold;
Limiting the torque generated by the motor generator when at least one of the three temperatures exceeds the corresponding first threshold,
If any of these three measured values is equal to or less than the corresponding first threshold value, the temperature of the cooling water and the outside air temperature of the hybrid vehicle are set to respective second preset values. Compared to the threshold,
If at least one of the two temperatures exceeds the corresponding second threshold, based on the temperature exceeding the second threshold and preset map data A method for controlling a hybrid vehicle, wherein each of the first threshold values is newly set. When both the temperature of the cooling water and the outside air temperature of the hybrid vehicle are equal to or lower than the second threshold value corresponding to each of them, those temperatures are set to respective preset third threshold values. Compared to
If at least one of the two temperatures exceeds the corresponding third threshold value, the rate of increase of the temperature of the battery, inverter and motor generator is set to each preset second value. 4 Compare with threshold,
The method for controlling a hybrid vehicle according to claim 4, wherein when at least one of the three increasing rates exceeds the corresponding fourth threshold value, the torque generated by the motor generator is limited.

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