JP2014108682A - Vehicular air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular air conditioning system that can effectively use exhaust heat of a motor device for heating while suppressing cost increase.SOLUTION: In an air conditioning device 4, exhaust heat of a motor device 3 is used for heating inside a cabin. During heating, a heating request corresponding to heat quantity required for the heating is made from an air conditioner ECU 6 to a motor ECU 5. While generation torque of the motor device 3 is held, the motor device 3 is controlled by the motor ECU 5 so that heat quantity of the motor device 3 reaches the heat quantity corresponding to the heating request. Thus, while an effect on traveling of a vehicle 1 is suppressed, the heat quantity of the motor device 3 is made to be the heat quantity required for the heating, so as to enable effective use of the exhaust heat of the motor device 3 for the heating.

Description

  The present invention relates to a vehicle air conditioning system, and more particularly to a vehicle air conditioning system suitable for an electric vehicle.

  In an automobile using an engine as a drive source, engine cooling water is supplied to a heater core for warming air blown by a blower, so that exhaust heat of the engine is used for heating. In contrast, in an electric vehicle not equipped with an engine, the exhaust heat of the engine cannot be used for heating.

  Therefore, for example, a PTC heater is mounted in an air conditioning system of an electric vehicle as a heat source for heating. Hot water is generated by the heat generated from the PTC heater, and the hot water is supplied to the heater core. Thereby, a heater core is heated and it warms when the ventilation by a blower passes a heater core.

  However, the air conditioning system is expensive because it requires a PTC heater and a high-voltage relay for supplying power to the PTC heater. In addition, a space for mounting a PTC heater or the like must be secured. Furthermore, since the PTC heater consumes battery power, the power consumption (power consumed for 1 km of travel) is deteriorated, and the travelable distance is reduced before the remaining battery level becomes zero.

  Thus, it has been proposed to use a motor for traveling and an inverter for driving the motor as a heat source for heating. That is, it has been proposed to supply cooling water circulating between the motor and the inverter and the radiator to the heater core, and to heat the heater core with the exhaust heat of the motor and the inverter. In addition, in order to effectively use the exhaust heat of the motor and the inverter for heating, it has been proposed to provide a shutter that adjusts the introduction of running air to the radiator.

JP 2011-229284 A

  However, providing a shutter increases the cost of the vehicle.

  An object of the present invention is to provide a vehicle air conditioning system that can effectively use the exhaust heat of a motor device for heating while suppressing an increase in cost.

  In order to achieve the above object, a vehicle air conditioning system according to the present invention controls a motor device that generates torque, an air conditioner that uses exhaust heat of the motor device for heating a vehicle interior, and the motor device. Motor control means and air conditioning control means for controlling the air conditioner, wherein the air conditioning control means outputs a heating request according to the amount of heat required for heating, and the motor control means generates torque generated by the motor device. The drive of the motor device is controlled so that the amount of heat of the motor device becomes the amount of heat corresponding to the heating request from the air conditioning control means.

  According to this configuration, in the air conditioner, the exhaust heat of the motor device is used for heating the passenger compartment. Therefore, compared with the structure provided with a PTC heater as a heat source for heating, the cost and space of the vehicle can be reduced, and the power consumption of the vehicle can be improved.

  During heating, a heating request corresponding to the amount of heat required for heating is given from the air conditioning control means to the motor control means. Then, the motor control unit controls the motor device so that the heat amount of the motor device becomes the heat amount corresponding to the heating request while the generated torque of the motor device is held. Thereby, the amount of heat of the motor device can be made the amount of heat necessary for heating while suppressing the influence on the operation using the output torque of the motor device.

  Therefore, the exhaust heat of the motor device can be effectively used for heating. Further, unlike the prior art, it is not necessary to provide a shutter for adjusting the amount of heat of the motor device, so that an increase in cost can be suppressed.

  The motor device includes at least a motor, and includes, for example, a motor and an inverter connected to the motor.

  The motor is, for example, a traveling motor that generates torque for traveling the vehicle. In this case, the amount of heat of the motor device can be set to the amount of heat necessary for heating while suppressing the influence on the running of the vehicle, and the exhaust heat of the motor device can be effectively used for heating.

  The motor control means is more efficient when the heat amount of the motor device is less than the heat amount according to the heating request from the air conditioning control means than when the heat amount of the motor device is equal to or more than the heat amount according to the heating request from the air conditioning control means. It is preferable to control the motor device so as to be worse.

  Thereby, when the heat quantity of a motor apparatus is less than the heat quantity according to the heating request | requirement from an air-conditioning control means, the heat quantity of a motor apparatus can be increased.

  The motor control means controls the motor apparatus so that the greater the difference is, the lower the efficiency is when the difference between the amount of heat corresponding to the heating request from the air conditioning control means and the loss of the motor apparatus is a predetermined value or less. Also good.

  Thereby, with respect to a heating request | requirement, the calorie | heat amount of a motor apparatus can increase rapidly and favorable heating performance can be exhibited.

  ADVANTAGE OF THE INVENTION According to this invention, the waste heat of a motor apparatus can be effectively utilized for heating, suppressing a cost increase.

FIG. 1 is a diagram schematically showing the configuration of a vehicle equipped with a vehicle air conditioning system according to an embodiment of the present invention. FIG. 2 is a flowchart showing the contents of processing by the motor ECU. FIG. 3 is a diagram illustrating an example of a loss-d-axis current map. FIG. 4 is a diagram illustrating an example of a d-axis-q-axis current map. FIG. 5 is a diagram illustrating an example of the ratio map.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram schematically showing the configuration of a vehicle equipped with a vehicle air conditioning system according to an embodiment of the present invention.

  The vehicle 1 is an electric vehicle. The vehicle 1 includes a driving battery 2, a motor device 3, and an air conditioner 4.

  The driving battery 2 is an assembled battery in which a plurality of secondary batteries are combined.

  The driving battery 2 can be charged with electric power (electric energy) supplied from the external power supply 11. For this charging, the vehicle 1 includes a charging receptacle 12 and a charger 13.

  The external power supply 11 is, for example, a household power supply (single-phase 100V or single-phase 200V AC power supply). One end of a charging cable 14 is connected to the external power source 11. A charging plug 15 is provided at the other end of the charging cable 14.

  The charging receptacle 12 is configured so that the charging plug 15 can be connected (coupled). By connecting the charging plug 15 to the charging receptacle 12, the external power supply 11 and the charging receptacle 12 are electrically connected.

  The charger 13 is electrically connected to the charging receptacle 12. With the charging plug 15 connected to the charging receptacle 12, AC power can be supplied from the external power supply 11 to the charger 13 through the charging cable 14. The charger 13 is electrically connected to the terminal of the driving battery 2. The charger 13 converts AC power from the external power source 11 into DC power that can charge the driving battery 2, and the driving battery 2 is charged with the DC power.

  The motor device 3 includes a drive motor 21 and an inverter 22.

  The drive motor 21 generates a driving force for traveling the vehicle 1. The driving force of the drive motor 21 is transmitted to the left and right drive wheels 24L and 24R via the drive shafts 23L and 23R, respectively.

  The inverter 22 receives supply of DC power from the drive battery 2, converts the DC power into AC power, and supplies the AC power to the drive motor 21.

  The air conditioner 4 includes an air conditioning duct 31, a heater core 32, a radiator 33, a cooling water circulation path 34, a water pump 35, and a three-way valve 36.

  The air conditioning duct 31 communicates with an air outlet (not shown) provided in the passenger compartment. In the air conditioning duct 31, air blown by a blower (not shown) flows toward the outlet.

  The heater core 32 is disposed in the air conditioning duct 31.

  The radiator 33 is disposed at a position where the traveling wind can be received in the front portion of the vehicle 1.

  The cooling water circulation path 34 passes through the motor device 3, the heater core 32, and the radiator 33. The cooling water circulation path 34 is filled with cooling water.

  The water pump 35 is interposed in the middle of the cooling water circulation path 34. When the water pump 35 is driven, the cooling water circulates through the cooling water circulation path 34. The cooling water circulating in the cooling water circulation path 34 absorbs heat from the motor device 3 to cool the motor device 3. The cooling water heated by the heat absorption from the motor device 3 passes through the heater core 32 and heats the heater core 32. When the blower blows air through the heater core 32, the blown air becomes warm air, and the warm air blows out from the air outlet into the vehicle interior. The cooling water that has passed through the heater core 32 flows through the cooling water circulation path 34 toward the radiator 33.

  The three-way valve 36 is interposed in the cooling water circulation path 34 on the downstream side of the cooling water flow direction with respect to the heater core 32 (hereinafter simply referred to as “flow direction”) and on the upstream side of the flow direction with respect to the radiator 33. One end of a bypass passage 37 is connected to the three-way valve 36. The other end of the bypass passage 37 is connected to a portion of the cooling water circulation passage 34 on the downstream side in the flow direction with respect to the radiator 33 and on the upstream side in the flow direction with respect to the motor device 3. With the three-way valve 36, the supply destination of the cooling water flowing through the cooling water circulation path 34 from the heater core 32 toward the radiator 33 is switched between the radiator 33 and the bypass path 37.

  The vehicle 1 also includes a motor ECU (electronic control unit) 5 and an air conditioner ECU 6.

  Motor ECU 5 includes a CPU and a memory. The motor ECU 5 is connected to a water temperature sensor 41 that detects the temperature of the cooling water flowing through the cooling water circulation path 34. The motor ECU 5 controls the inverter 22. Further, the motor ECU 5 controls the water pump 35 and the three-way valve 36 based on the water temperature detected by the water temperature sensor 41 for cooling the motor device 3.

  The air conditioner ECU 6 includes a CPU and a memory. The air conditioner ECU 6 controls the air conditioner 4 to adjust the room temperature in the passenger compartment.

The motor ECU 5 and the air conditioner ECU 6 are connected to a CAN (Controller Area).
Network) communication protocol can be mutually performed. The air conditioner ECU 6 outputs a heating request according to the amount of heat necessary for heating to the motor ECU 5 based on the target room temperature in the vehicle interior and the current room temperature.

  FIG. 2 is a flowchart showing the contents of processing by the motor ECU.

  While the ignition key switch (start switch) of the vehicle 1 is turned on, the process shown in FIG. 2 is repeatedly executed by the motor ECU 5.

  First, in order to set a threshold value for switching the three-way valve 36, it is determined whether or not a heating request is output from the air conditioner ECU 6 (step S1).

  When the heating request is output (YES in step S1), the threshold is set to a predetermined relatively high threshold H (step S2).

  When the heating request is not output (NO in step S1), the threshold is set to a predetermined relatively low threshold L (step S3).

  Next, with reference to the detection signal of the water temperature sensor 41, it is determined whether or not the temperature of the cooling water flowing through the cooling water circulation path 34 is higher than the previously set threshold values L and H (step S4).

  When the coolant temperature is higher than the threshold values L and H (YES in step S4), the port on the radiator 33 side of the three-way valve 36 is opened, and the port on the bypass path 37 side is closed (step S5). At this time, the cooling water flows through the radiator 33 and is cooled by the traveling air received by the radiator 33.

  When the coolant temperature is below the threshold values L and H (NO in step S4), the port on the bypass path 37 side of the three-way valve 36 is opened, and the port on the radiator 33 side is closed (step S5). At this time, the cooling water flows through the bypass passage 37 and bypasses the radiator 33.

  Further, an average loss X that is an average value of the losses of the motor device 3 in the latest predetermined time is obtained. Then, it is determined whether the amount of heat corresponding to the heating request output from the air conditioner ECU 6, that is, the amount of heat necessary for heating (hereinafter simply referred to as “heating request”) is greater than the average loss X (step S7). ).

  When the heating request is larger than the average loss X (YES in step S7), it is determined whether or not the heating request is larger than the current loss Y that is the current loss of the motor device 3 (step S8).

  When the heating request is larger than the average loss X and the current loss Y (YES in step S8), it is determined that the amount of heat for heating is insufficient, and the d-axis for heating is used as the current command value of the drive motor 21. A current command value and a q-axis current command value are set (step S9).

  The d-axis current command value and the q-axis current command value for heating are based on a heating request and a torque command value that is a torque necessary for traveling of the vehicle 1. It is set with reference to the q-axis current map. The loss-d-axis current map and the d-axis-q-axis current map are stored in the memory (ROM) of the motor ECU 5.

  An example of a loss-d-axis current map is shown in FIG. The loss-d-axis current map is created for each torque command value T1, T2, T3,... And is a map that defines the relationship between the loss of the motor device 3 and the d-axis current command value Id (Id <0). is there.

  An example of the d-axis-q-axis current map is shown in FIG. A d-axis-q-axis current map is created for each torque command value T1, T2, T3,..., and the torque command values T1, T2, T3,. It is the map which defined d axis current command value and q axis current command value which can be done.

  When setting the d-axis current command value and the q-axis current command value for heating, a loss-d-axis current map and a d-axis-q-axis current map corresponding to the torque command value are selected. The torque command value is set by the motor ECU 5 based on an operation amount of an accelerator pedal (not shown) of the vehicle 1. Then, the loss-d-axis current map is referred to, and a d-axis current command value that provides a loss equal to the heating request is set. Thereafter, the d-axis-q-axis current map is referred to, and the q-axis current command value corresponding to the d-axis current command value is set.

  When the d-axis current command value and the q-axis current command value for heating are set, the d-axis voltage command value and the q-axis voltage command value are obtained based on the d-axis current command value and the q-axis current command value. . Then, the d-axis voltage command value and the q-axis voltage command value are subjected to dq / three-phase AC coordinate conversion, and based on the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value obtained by this conversion. The inverter 22 is controlled by PWM (Pulse Width Modulation) (step S10). As a result, torque corresponding to the torque command value is output from the drive motor 21, a loss corresponding to the heating request is generated in the motor device 3, and the heat amount of the motor device 3 becomes the heat amount corresponding to the heating request.

  On the other hand, when the heating request is equal to or less than the average loss X or the current loss Y (NO in steps S7 and S8), it is determined that the amount of heat for heating is sufficient, and the current command value of the drive motor 21 is used as a normal command value. D-axis current command value and q-axis current command value are set (step S11). The normal d-axis current command value and the q-axis current command value are set so that the efficiency of the motor device 3 is maximized while the torque corresponding to the torque command value can be output from the drive motor 21.

  In addition, when the heating request is equal to or less than the average loss X or the current loss Y, the case where the heating request is not output is included.

  When the normal d-axis current command value and the q-axis current command value are set, the d-axis voltage command value and the q-axis voltage command value are obtained based on the d-axis current command value and the q-axis current command value. . Then, the d-axis voltage command value and the q-axis voltage command value are subjected to dq / three-phase AC coordinate conversion, and based on the U-phase voltage command value, the V-phase voltage command value, and the W-phase voltage command value obtained by this conversion. The inverter 22 is PWM-controlled (Step S10). As a result, torque corresponding to the torque command value is output from the drive motor 21 and the motor device 3 is driven at the most efficient operating point.

  As described above, in the air conditioner 4, the exhaust heat of the motor device 3 is used for heating the passenger compartment. Therefore, the cost and space of the vehicle 1 can be reduced as compared with the configuration in which the PTC heater is provided as a heat source for heating, and a necessary amount can be obtained while using the waste heat of the conventional motor device 3. Since the calorific value is increased only, the power consumption of the vehicle 1 can be improved.

  At the time of heating, a heating request corresponding to the amount of heat necessary for heating is given from the air conditioner ECU 6 to the motor ECU 5. The motor ECU 3 controls the motor device 3 so that the amount of heat of the motor device 3 becomes the amount of heat corresponding to the heating request while the generated torque of the motor device 3 is maintained. Thereby, while suppressing the influence on driving | running | working of the vehicle 1, the calorie | heat amount of the motor apparatus 3 can be made into the calorie | heat amount required for heating, and the waste heat of the motor apparatus 3 can be utilized effectively for heating.

  When the average loss X and the current loss Y corresponding to the heat amount of the motor device 3 are less than the heat amount corresponding to the heating request from the air conditioner ECU 6, the heat amount of the motor device 3 is equal to or more than the heat amount corresponding to the heating request from the air conditioner ECU 6. The motor ECU 3 is controlled by the motor ECU 5 so that the efficiency is worse than that in the case of the above, that is, the loss of the motor apparatus 3 is increased. Thereby, when the calorie | heat amount of the motor apparatus 3 is less than the calorie | heat amount according to the heating request | requirement from air-conditioner ECU6, the calorie | heat amount of the motor apparatus 3 can be increased.

  Note that the predetermined period, which is a period for obtaining the loss of the motor device 3 in order to obtain the average loss X, may be a preset fixed value or may be variable based on the difference between the heating request and the average loss X. May be set. For example, the larger the difference between the heating request and the average loss X, the shorter the predetermined period may be set, and the set predetermined period may be used the next time the average loss X is obtained.

  Thereby, when the difference between the heating request and the average loss X is large, the average loss X can be brought close to the current loss of the motor device 3, and the heat amount of the motor device 3 can be made to follow the heating request well. .

  As mentioned above, although embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-described embodiment, the loss-d-axis current map is referred to and the d-axis current command value that provides a loss equal to the heating request is set. Not limited to this, when the difference between the heating request and the average loss X is small, a ratio corresponding to the difference is multiplied by the heating request, and a d-axis current command value is set to obtain a loss equal to the multiplied value. Also good.

  In this case, the ratio multiplied by the heating request may be set with reference to the ratio map shown in FIG.

  In the ratio map, a relationship between a loss difference and a ratio, which is a difference between the heating request and the average loss X, is defined. The ratio map is determined such that, for a loss difference smaller than the predetermined value D, the ratio is set to a smaller value as the loss difference is smaller. The ratio map is created so that the ratio is set to 100% for a loss difference equal to or greater than a predetermined value D.

  When the ratio set with reference to the ratio map is multiplied by the heating request and the d-axis current command value is set to obtain a loss equal to the multiplied value, the loss of the motor device 3 is reduced. Reduction in efficiency can be suppressed. Moreover, the greater the loss difference, the lower the efficiency of the motor device 3 and the greater the amount of heat of the motor device 3. Therefore, the amount of heat of the motor device can be quickly increased in response to the heating request, and good heating performance can be exhibited.

  Moreover, although the electric vehicle is taken up as an example of the vehicle 1, the present invention can be widely applied to vehicles including a motor device such as a range extended electric vehicle and a hybrid car.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

3 Motor device 4 Air conditioning device 5 Motor ECU (motor control means)
6 Air conditioner ECU (air conditioning control means)

Claims (3)

A motor device for generating torque;
An air conditioner that uses the exhaust heat of the motor device to heat the passenger compartment; and
Motor control means for controlling the motor device;
Air conditioning control means for controlling the air conditioning device,
The air conditioning control means outputs a heating request corresponding to the amount of heat required for heating,
The motor control means controls the drive of the motor device so that the amount of heat of the motor device becomes the amount of heat corresponding to the heating request from the air conditioning control means while maintaining the torque generated by the motor device. Air conditioning system.   When the amount of heat of the motor device is less than the amount of heat according to the heating request from the air conditioning control unit, the amount of heat of the motor device is equal to or greater than the amount of heat according to the heating request from the air conditioning control unit. The vehicle air conditioning system according to claim 1, wherein the motor device is controlled so as to be less efficient than the case.   In the range where the difference between the amount of heat corresponding to the heating request from the air conditioning control unit and the loss of the motor device is less than or equal to a predetermined value, the motor control unit is configured such that the greater the difference, the worse the efficiency. The air conditioning system for vehicles according to claim 1 or 2 which controls.

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