JP2011061909A - Electric vehicle - Google Patents

Abstract

In an electric vehicle, by correcting a power consumption calculation value of an electric air conditioner according to the remaining amount of the battery, a deviation between the generated power and the actual power consumption due to a sensor error is eliminated, and the battery is overcharged. And suppresses overdischarge.
A hybrid vehicle includes a battery, a motor that receives power supply from the battery and outputs driving power, an electric air conditioner that is driven by the power from the battery, and an SOC of the battery. A controller 26 that controls within a target range and a motor 24 that generates power in response to a command from the controller 26 are provided. Controller 26, when SOC of the battery 16 is larger than the target range upper limit value P _UL performs correction to reduce the power consumption calculation value of the electric air conditioner 49, when SOC of the battery 16 is smaller than the target range lower limit P _LL is Correction for increasing the power consumption calculation value of the electric air conditioner 49 is executed.
[Selection] Figure 3

Description

  The present invention relates to an electric vehicle, and more particularly to an electric vehicle equipped with an electric air conditioner.

  2. Description of the Related Art Conventionally, an electric vehicle that drives a motor with electric power discharged from a battery to output traveling power is known, and hybrid vehicles that use an engine and a motor together as a traveling power source are widely used.

  In the hybrid vehicle described above, the motor is a motor generator that functions as an electric motor and outputs motive power for driving, and also functions as a generator that generates electric power by receiving power input from wheels and engine power during regenerative braking. Yes, the electric power generated by the motor is charged in the battery. For the battery, a secondary battery such as a lithium ion battery capable of repeatedly charging and discharging high voltage power is preferably used, so that the remaining capacity (SOC) of the battery is maintained within a predetermined target range. Managed and controlled by the controller.

  The high-voltage power discharged from the battery is not only used as driving power for the driving motor, but is also consumed as driving power for various auxiliary devices mounted on the vehicle, such as electric air conditioners, cooling fans, and fuel pumps. The The driving power of these auxiliary machines is supplied by stepping down the high voltage power from the battery to a low voltage of, for example, 12V by the DC / DC converter.

  When the battery needs to be charged, the controller drives the motor with the engine power to generate power. At that time, the controller generates power by adding the battery required charge (kW) to the power consumption (kW) of the auxiliary equipment. It may be generated as a power command. The power consumption of the auxiliary equipment includes the power consumption calculation value of the refrigerant compressor motor of the electric air conditioner. The power consumption calculation value is detected by each of the voltage sensor and the current sensor provided in the power supply path of the refrigerant compressor motor. Calculated based on the value.

  However, the detection accuracy by the voltage sensor and current sensor may be poor. In such a case, the calculated power consumption value of the refrigerant compressor motor calculated from the voltage value and current value detected by these sensors deviates from the actual power consumption. When the generated power command value is generated including such a power calculation value that is inaccurate, i.e., deviated from the actual power consumption, the power generated by the generator is in an excessive state or a short state, and as a result The balance of power balance may be lost, leading to battery overcharge or overdischarge.

  For example, Patent Documents 1 and 2 below describe that control for suppressing power consumption by an electric air conditioner is executed when the remaining capacity of the battery is reduced.

JP 2004-66847 A Japanese Patent Laid-Open No. 9-315139

  However, even if the control for suppressing the power consumption of the electric air conditioner is performed as described in Patent Documents 1 and 2, the calculated power consumption value of the electric air conditioner due to the sensor error is calculated from the actual power consumption as described above. If it is deviated, there may still be a situation where the remaining battery level is out of the target range.

  The object of the present invention is to correct the calculated power consumption value of the electric air conditioner according to the remaining amount of the battery, thereby eliminating the deviation between the generated power and the actual power consumption due to the sensor error, and overcharging the battery. The object is to provide an electric vehicle that suppresses overdischarge.

  An electric vehicle according to the present invention includes a chargeable / dischargeable battery, a motor that receives power supply from the battery and outputs driving power, an electric air conditioner that is driven by the power from the battery, and a remaining capacity of the battery in a target range. An electric vehicle comprising: a controller for controlling the power supply and a generator for generating electric power in response to a command from the controller, wherein the controller calculates the power consumption of the electric air conditioner when the remaining battery capacity is greater than a target range upper limit value Correction for decreasing the value is executed, and correction for increasing the power consumption calculation value of the electric air conditioner is executed when the remaining battery capacity is smaller than the target range lower limit value.

  In the electric vehicle according to the present invention, the controller that controls the remaining capacity of the battery to the target range executes correction to decrease the calculated power consumption value of the electric air conditioner when the remaining capacity of the battery is larger than the upper limit value of the target range, When the remaining capacity is smaller than the target range lower limit value, a correction for increasing the power consumption calculation value of the electric air conditioner is executed. As a result, the overcharge and overdischarge of the battery caused by the calculated power consumption of the electric air conditioner deviating from the actual power consumption due to the sensor error can be suppressed to prevent the battery performance from being lowered or shortened. it can.

1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is a schematic block diagram of the electric air conditioner which is one of the vehicle-mounted auxiliary machines. It is a flowchart which shows the process sequence which correct | amends the power consumption calculation value of an electric air-conditioner based on the remaining capacity of a battery.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  In the following, as an example of the electric vehicle according to the present invention, a hybrid vehicle equipped with two motors, a motor that mainly functions as an electric motor and outputs driving power and a motor that mainly functions as a generator will be described. The invention may be applied to a hybrid vehicle in which only one motor used as a driving power source and a generator is mounted, or a hybrid vehicle in which a battery charging port or a battery charging device is mounted in the vehicle. Further, the present invention may be applied to an electric vehicle in which only a motor is mounted as a traveling power source. In this case, the motor that is the traveling power source functions as a generator during regenerative braking of the vehicle.

  FIG. 1 shows a schematic configuration of a hybrid vehicle 10 according to an embodiment of the present invention. In FIG. 1, the power transmission system is illustrated as a round bar-shaped shaft element, the power system is illustrated by a solid line, and the signal system is illustrated by a broken line.

  The hybrid vehicle 10 includes a power to which an engine 12 as a driving power source, a second motor (indicated as “MG2” in the drawing) 14 as another driving power source, and an output shaft 18 of the engine 12 are coupled. A first motor 24 (shown as “MG1” in the figure) to which the rotary shaft 22 is connected via the distribution mechanism 20, a battery 16 capable of supplying drive power to the first and second motors 24, 14; A controller (indicated as “ECU (Electronic Control Unit)” in FIG. 1) that comprehensively controls the operation of the engine 12 and the motors 24, 12 is provided.

  The engine 12 is an internal combustion engine that uses gasoline or the like as fuel, and is controlled to start, operate, stop, and the like based on a command from the controller 26. Further, an engine speed sensor 28 for detecting the engine speed Ne is provided in the vicinity of the output shaft 18 extending from the engine 12 to the power distribution mechanism 20, and the engine speed Ne detected by the sensor 28 is determined. The data is input to the controller 26.

  The power distribution mechanism 20 can be suitably configured by, for example, a planetary gear mechanism. The power input from the engine 12 to the power distribution mechanism 20 via the output shaft 18 is transmitted to the drive wheels 34 via the speed reducer 30 and the axle 32, so that the hybrid vehicle 10 can travel with the engine power.

  Further, the power distribution mechanism 20 can input a part or all of the power of the engine 12 input via the output shaft 18 to the first motor 24 via the rotation shaft 22. At this time, for example, the first motor 24 suitably configured by a three-phase synchronous AC motor functions as a generator, and after the generated three-phase AC voltage is converted into a DC voltage by the inverter 36, Can be charged.

  Further, the first motor 24 can also function as an electric motor that is rotationally driven by the electric power supplied from the battery 16 via the inverter, and the first motor 24 is rotationally driven and output to the rotating shaft 22. The motive power is input to the engine 12 through the power distribution mechanism 20 and the output shaft 18, and the engine 12 is cracked when the engine 12 is started. That is, the first motor 24 functions as a cell motor.

  The second motor 14 that mainly functions as an electric motor can be suitably configured by, for example, a three-phase synchronous AC motor, and the DC voltage supplied from the battery 16 is converted into a three-phase AC voltage by the inverter 38 and driven. It is rotationally driven by being applied as a voltage. The power output by driving the second motor 14 to the rotary shaft 15 is transmitted to the drive wheels 34 via the speed reducer 30 and the axle 32, thereby enabling electric traveling or EV traveling. The second motor 14 also has a function of assisting the engine output by outputting the driving power when there is a sudden acceleration request to the hybrid vehicle 10 by the user's accelerator operation.

  Further, the second motor 14 can function as a power generator during regenerative braking of the vehicle, and generates AC power by power input from the drive wheels 34 via the speed reducer 30 and the rotating shaft 15. The three-phase AC voltage generated and output by the second motor 14 can be charged into the battery 16 after being converted into a DC voltage by the inverter 38.

  As the inverters 36 and 38, those having a known configuration having a bidirectional AC / DC conversion function can be used as described above. Further, the electric power generated by the first motor 24 can be directly supplied from the inverter 36 to the inverter 38 and used as the driving electric power for the second motor 14.

  As the battery 16, a chargeable / dischargeable secondary battery such as a lithium ion battery or a nickel metal hydride battery can be suitably used. The battery 16 is provided with a voltage sensor 40 that detects the battery voltage Vb, a current sensor 42 that detects the battery current Ib that enters and leaves the battery 16, and a temperature sensor 44 that detects the temperature Tb of the battery 16. Detection values from the sensors 40, 42, and 44 are input to the controller 26 and used to manage and control the SOC (State Of Charge) of the battery 16.

  A DC / DC converter 46 is connected to a pair of power lines connected to the battery 16. The DC / DC converter 46 is a voltage converter having a function of stepping down a high-voltage power of, for example, 200 V discharged from the battery 16 to a low-voltage power of, for example, 12 V, and includes a power switching element (for example, an IGBT). The well-known structure can be used. The DC / DC converter 46 is controlled in response to a signal from the controller 26.

  A vehicle-mounted auxiliary device 48 is connected to the output terminal of the DC / DC converter 46. The in-vehicle auxiliary equipment 48 is driven by the low-voltage power stepped down by the DC / DC converter 46. However, in order to stably supply power to the in-vehicle auxiliary equipment 48, an auxiliary battery (for example, a lead battery (rated voltage 12V) that can be charged / discharged between the DC / DC converter 46 and the in-vehicle auxiliary equipment 48). (Not shown) may be electrically connected, and a part of the in-vehicle auxiliary equipment 48 may be driven by electric power supplied from the auxiliary battery. Here, the in-vehicle auxiliary equipment 48 includes an electric air conditioner 49 (see FIG. 2), a cooling fan, a fuel pump, switches, sensors, a control computer, and the like.

  The electric air conditioner 49 is an electric air conditioner that performs an air conditioning operation by driving a motor or the like included therein by reducing the DC power discharged from the battery 16 by the DC / DC converter 46 and supplying it. The operation of the electric air conditioner 49 is controlled in response to a signal from the controller 26, and a signal indicating a setting state by a user operation, specifically, an on / off setting, a temperature setting, an air volume setting, and the like is transmitted to the controller 26. It is like that.

  The controller 26 is preferably configured as a microcomputer including a CPU for executing various control programs, a ROM for storing control programs in advance, a RAM for temporarily storing detection values of the sensors 40, 42, and 44, and the like. Can. The controller 26 includes an input port for inputting an engine speed Ne, a battery current Ib, a battery voltage Vb, a battery temperature Tb, an accelerator opening signal Acc, a vehicle speed Sv, and the like, as well as the engine 12, inverters 36 and 38, DC / DC. An input / output interface including an output port for outputting a control signal for controlling the operation of the converter 46 and the electric air conditioner 49 is provided. The ROM stores in advance a correction coefficient used for correcting a power consumption calculation value of an electric air conditioner 49 described later in the form of a table or a map.

  In the hybrid vehicle 10 of the present embodiment, the controller 26 is described as controlling the entire vehicle in a lump. However, the engine 12, the motors 14, 24, the battery 16, and the like are each a separate controller (an engine ECU, a motor). For example, an ECU for the battery, an ECU for the battery, etc.), and the controller 26 may communicate with each of the individual controllers to control the whole.

  FIG. 2 schematically shows the configuration of the electric air conditioner 49. The electric air conditioner 49 includes a fan 52 that is rotationally driven by a blower motor 51, an evaporator 54 that forms part of the refrigerant system 60, an electric heater 56 that generates heat when supplied with power, and a servo (not shown). A switching door member 58 that is rotated by a motor to switch the air intake passage to the outside of the vehicle or the passenger compartment is configured.

  The refrigerant system 60 is configured by connecting a evaporator 66, a compressor 66 driven by a compressor motor 64, a radiator 68, and an expansion valve 70 in a loop shape with a refrigerant pipe 72. The refrigerant is compressed by the compressor 66 to become a high-temperature and high-pressure gaseous refrigerant and sent to the radiator 68. When passing through the radiator 68, the refrigerant dissipates heat to the outside to become a high-temperature and high-pressure liquid refrigerant. Then, when the expansion valve 70 is opened and closed at a predetermined timing, the refrigerant becomes a low-temperature and low-pressure mist refrigerant and is sent to the evaporator 54. In the evaporator 54, the low-temperature and low-pressure refrigerant flowing through the interior absorbs heat from the air flowing through the evaporator 54 to generate cold air. The refrigerant that has passed through the evaporator 54 returns to the compressor 66. In this way, when the electric air conditioner 49 is operated in the cooling mode, the cold air whose temperature is adjusted to a predetermined set temperature is sent to the vehicle interior air passage 63. The cold air temperature during cooling can be set to a desired temperature by adjusting the rotation speed of the compressor motor 64, the opening / closing timing of the expansion valve 70, and the like. The power supply path to the compressor motor 64 is provided with a voltage sensor and a current sensor (both not shown), and the controller 64 multiplies each detection value of the voltage sensor and the current sensor to consume power of the compressor motor 64. A calculated value can be calculated.

  Further, the rotational speed of the blower motor 51 included in the electric air conditioner 49 changes according to three steps of air volume setting selected by user operation or automatically, for example, air volume low, medium, and strong, and the controller 26 at that time Electric power is supplied to the blower motor 51 so that the number of rotations of the blower motor 51 corresponds to the air volume setting.

  On the other hand, when the electric air conditioner 49 is operated in the heating mode, electric power is supplied to the electric heater 56 to generate heat, and warm air is generated by heating the air flowing around the heater. The temperature of the hot air is set to a desired temperature by adjusting the amount of heat generated by the electric power supplied to the electric heater 56.

  The blower motor 51 and the electric heater 56 included in the electric air conditioner 49 are driven by being supplied with electric power from the auxiliary battery. The auxiliary battery is appropriately charged by the output voltage from the DC / DC converter 46.

  Next, the operation of the hybrid vehicle 10 having the above configuration will be briefly described. When a start switch (not shown) is turned on by the user, electric power is supplied from the battery 16 to the first motor 24 via the inverter 36 and driven, whereby the engine 12 is cranked and started. Thereafter, when the vehicle travels EV at the start, the engine 12 is stopped when the warm-up operation ends.

  When the vehicle speed Sv is from a low speed range to a medium speed range, if the vehicle acceleration corresponding to the accelerator depression amount by the user is relatively moderate, the battery 16 is connected to the inverter 38 on the condition that the output is not limited. Then, the second motor 14 is driven by the power supply via the power supply, and thus EV traveling is performed. On the other hand, when the vehicle speed Sv changes from the medium speed range to the high speed range, or when there is a relatively large vehicle acceleration request due to the user's accelerator operation, the engine 12 is driven to output the driving power. If necessary, the driving power is also output from the second motor 14.

  The controller 26 constantly monitors and controls so that the SOC of the battery 16 is maintained within a target range (for example, 40 to 80%). The controller 26 generates a generated power command when the battery 16 needs to be charged. When this generated power command is issued, the first motor 24 is driven by the engine power to generate power, and the generated power command value at that time is the battery charge amount (kW) and the in-vehicle accessories 48. Is generated as a value obtained by adding the power consumption (kW). The power consumption of the in-vehicle auxiliary equipment 48 includes a power consumption calculation value of the compressor motor 64 of the electric air conditioner 49, and this power consumption calculation value is a voltage sensor and a current sensor provided in the power supply path of the compressor motor 64. Calculated based on the detected value.

  However, the detection accuracy by the voltage sensor and current sensor may be poor. At such time, the calculated power consumption value of the compressor motor 64 calculated from the voltage value and current value detected by these sensors will deviate from the actual power consumption. If the generated power command value is generated including such a power calculation value that is inaccurate, that is, deviated from the actual power consumption, the power generated by the first motor 24 becomes excessive or insufficient. As a result, the balance of power balance may be lost, leading to overcharge or overdischarge of the battery 16.

  Therefore, in the hybrid vehicle 10 of the present embodiment, the controller 26 performs control as shown in FIG. The control shown in FIG. 3 is executed every predetermined time (for example, several milliseconds) when the electric air conditioner 49 is driven by the compressor motor 64.

First, in step S10, whether or not SOC of battery 16 is greater than the upper limit value P _UL of the target range is determined. When this determination is affirmative, in a subsequent step S12, correction for reducing the calculated power consumption value of the electric air conditioner 49, more specifically, the calculated power consumption value of the compressor motor 64 is executed.

If the determination in step S10 is negative, the process proceeds to step S14. In step S14, it is determined whether or not the SOC of the battery 16 is smaller than the lower limit value _{PLL of the} target range. When this determination is negative, since the SOC of the battery 16 is within the target range, the processing is ended as it is. On the other hand, when the determination in step S14 is affirmative, a correction for increasing the power consumption calculation value of the electric air conditioner 49, more specifically, the power consumption calculation value of the compressor motor 64, is executed, and the series of processing ends. .

  In the above, correction of the power consumption calculation value of the compressor motor 64 is obtained by referring to a table or the like stored in the ROM for the gain of at least one sensor for detecting the voltage and current applied to the compressor motor 64. This is done by multiplying the coefficients. For example, when the calculated power consumption value is decreased in step S12, the correction coefficient is set to 0.95, for example. On the other hand, when the calculated power consumption value is increased in step S16, the correction coefficient is set to 1 for example. .05 is set.

  By correcting the power consumption calculation value of the compressor motor 64 in this way, the generated power command value generated by the controller 26 becomes appropriate, and the power generated by the first motor 24 is excessive or insufficient. Is resolved. Thereby, the overcharge and overdischarge of the battery 16 caused by the calculated power consumption value of the compressor motor 64 deviating from the actual power consumption due to the sensor error can be suppressed. Shortening of life can be prevented.

  In the above description, the calculated power consumption value of the electric air conditioner 49 is only related to the compressor motor 64. However, the blower motor 51 and the electric heater 56 which are other power consumption elements included in the electric air conditioner 49 are also DC / When driven by the output voltage of the DC converter 46, the calculated power consumption values of the compressor motor 64, the blower motor 51, and the electric heater 56 may be summed to obtain the total power consumption value of the electric air conditioner 49.

  In addition, the correction coefficient used for correcting the power consumption calculation value of the electric air conditioner 49 in the above is stored in advance in a plurality of values in each case of the increase or decrease of the power consumption calculation value, and the sensor gain You may make it select suitably according to the correction | amendment degree.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 12 Engine, 14 2nd motor, 15 Rotating shaft, 16 Battery, 18 Output shaft, 20 Power distribution mechanism, 22 Rotating shaft, 24 1st motor, 26 Controller, 28 Engine speed sensor, 30 Deceleration Machine, 32 axles, 34 drive wheels, 36, 38 inverter, 40 voltage sensor, 42 current sensor, 44 temperature sensor, 46 DC / DC converter, 48 in-vehicle accessories, 49 electric air conditioner, 50 air passage forming member, 51 blower motor , 52 Fan, 54 Evaporator, 56 Electric heater, 58, 62 Switching door member, 60 Refrigerant system, 63 Car interior ventilation passage, 64 Compressor motor, 66 Compressor, 68 Radiator, 70 Expansion valve, 72 Refrigerant piping.

Claims (1)

A chargeable / dischargeable battery, a motor that receives power supply from the battery and outputs driving power, an electric air conditioner driven by the power from the battery, a controller that controls the remaining capacity of the battery within a target range, and a controller An electric vehicle including a generator that generates power in response to a command from
The controller performs correction to decrease the calculated power consumption value of the electric air conditioner when the remaining battery capacity is greater than the target range upper limit value, and calculates the power consumption of the electric air conditioner when the remaining battery capacity is less than the target range lower limit value. An electric vehicle characterized by executing correction for increasing the value.

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