JP2844110B2 - Air conditioning control device for electric vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electric vehicle which reduces the power consumption of an air conditioner when the battery voltage of the electric vehicle falls below a reference value, and helps the vehicle to run smoothly. The present invention relates to an air conditioning control device.

2. Description of the Related Art As disclosed in Japanese Patent Publication No. 54-5573, in a cooling device of a hybrid electric vehicle, a power generation system in which a power generation device directly connected to a rated operation internal combustion engine and a storage battery are connected in parallel. The vehicle drive motor is driven by the source,
In the steady operation of the vehicle, the refrigerant compressor is driven by the engine or the electric motor, and in the acceleration operation requiring large power, the refrigerant compressor is stopped, and the brain is cooled and stored by the refrigeration cycle including the refrigerant compressor, Brain flows through the indoor heat exchanger to cool the room.

According to the cooling device described above, even if the refrigerant compressor is operated intermittently so as not to impair the acceleration of the electric vehicle, a substantially uniform blow-out temperature can be obtained, but the configuration is complicated and the internal combustion engine is mounted. It cannot be applied to ordinary electric vehicles powered by batteries.

[Problems to be Solved by the Invention] The object of the present invention is simple in view of the above-mentioned problems, the configuration is simple, and when the battery voltage falls below the reference value, the power consumption of the air conditioner is reduced to make the vehicle smooth. An object of the present invention is to provide an air-conditioning control device for an electric vehicle that assists driving.

Means for Solving the Problems In order to achieve the above object, the configuration of the present invention provides a voltage sensor for detecting a battery voltage, and an electric vehicle powered by an electronic battery having a voltage detected by the voltage sensor as an input. , A voltage sensor for detecting the voltage of the battery, an electronic control device that receives the voltage detected by the voltage sensor as an input, and an electric motor that drives a refrigerant compressor using the battery as a power source, the electronic control device Is characterized in that when the detection voltage of the voltage sensor is lower than a reference value, the amount of power reduced according to the voltage difference between the detection voltage and the reference value is applied to the motor.

Also, in a configuration of the present invention, in an electric vehicle that uses a battery as a power source, a voltage sensor that detects a voltage of the battery, an electronic control device that receives a detection voltage of the voltage sensor as an input, and a refrigerant compressor that uses the battery as a power source. An electric motor for driving the motor, the electronic control unit, when the detected voltage of the voltage sensor is lower than a reference value, corresponding to the voltage difference between the detected voltage and the reference value, the set temperature during cooling. It is characterized in that the temperature is automatically set higher than the set temperature set during normal operation.

[Operation] When the battery voltage detected by the voltage sensor becomes lower than the reference value, the voltage applied from the electronic control unit to the air conditioner such as the electric motor driving the refrigerant compressor is reduced in accordance with the voltage drop. In addition, the power consumption of the air conditioner is reduced, excessive power consumption of the battery is suppressed, and a situation in which the vehicle cannot run due to a decrease in the acceleration of the vehicle or the consumption of the battery is avoided.

FIG. 1 is a block diagram of a control device of an electric vehicle including an air conditioner according to the present invention, FIG. 2 is a refrigeration cycle diagram of the air conditioner, and FIG. 3 is software of a program of the control device. It is a flowchart of.

As shown in FIG. 2, the heat pump type air conditioner has a four-way switching valve 6 at a discharge port of a refrigerant compressor C driven by an electric motor, an indoor heat exchanger 8 disposed in a vehicle compartment, a decompressor 9, an outdoor heat exchanger. The refrigeration cycle is formed by connecting the refrigerant compressor C via the exchanger 3, the four-way switching valve 6, and the accumulator A to the suction port of the refrigerant compressor C via pipes 12 to 17.

In the heating operation, the refrigerant is circulated in the arrow direction by the refrigerant compressor C, and the vehicle interior is heated by the indoor heat exchanger 8, while
In the cooling operation, the four-way switching valve 6 is switched as shown by a broken line, and the refrigerant is circulated in the direction opposite to the arrow, so that the indoor heat exchanger 8
To cool the passenger compartment. In the case of the heating operation, in order to prevent the connection of the outdoor heat exchanger 3, when the temperature of the outdoor heat exchanger 3 becomes lower than a predetermined value, the electromagnetic on-off valve 5 opens, and the high temperature discharged from the refrigerant compressor C becomes high. The high-pressure refrigerant is supplied to the outdoor heat exchanger 3
Flow through to

As shown in FIG. 2, a refrigerant compressor C, a blower 4 for blowing the heated air cooled by the indoor heat exchanger 8 to the vehicle interior, and a cooling and heating unit for cooling or heating the outdoor heat exchanger 3. Each electric motor that drives the blower 2 is driven by a battery 21, and the number of revolutions is controlled by an electronic control unit 23. The electric motor for driving the vehicle is also driven by the battery 21, and the number of revolutions is controlled by the control device 22.

The voltage of battery 21 is higher than the reference value immediately after charging,
It decreases with the traveling time and eventually falls below the reference value. Therefore, when the air conditioner 24 is continuously operated, the voltage supplied to the motor for driving the vehicle also becomes low, and sufficient acceleration performance cannot be exhibited particularly in acceleration operation with a large load. If the voltage applied to the motor for driving the vehicle becomes abnormally low, the vehicle may be unable to travel.

Therefore, the present invention provides a voltage applied to the air conditioner 24 when the voltage V of the battery 21 becomes lower than the reference value V2 by the electronic control device 23 composed of a microcomputer, that is, the electric motor or the blower 2 that drives the refrigerant compressor C. , 4 are reduced in accordance with the amount of voltage drop of the battery 21 to reduce the power consumption of the air conditioner 24.

When the battery voltage V is higher than the reference value V1 (for example, immediately after the battery is charged), when this voltage V is applied to the air conditioner 24, the cooling / heating capacity becomes excessive, power is wasted, and the reliability of the air conditioning control is also increased. Will be damaged. In this case the electronic control unit
23, the battery voltage V is reduced to the reference value V1 and the air conditioner
In addition to 24, maintain the normal operation of the air conditioner 24.

In order to reduce the power consumption of the air conditioner 24, for example, the duty ratio of the pulse current applied to the refrigerant compressor C or the electric motor of the blower or the frequency of the alternating current is adjusted to adjust the rotation speed of the refrigerant compressor C or the blower. In the case of a variable displacement type refrigerant compressor such as a basil type, the discharge amount variable mechanism is electrically controlled instead of directly adjusting the supply power. Further, for example, the set temperature (target value), which is a factor for controlling the output of the refrigerant compressor C, is changed to a value at which the load on the refrigerant compressor C becomes lighter than the optimum value in accordance with the battery voltage drop amount ( For example, if the set temperature during cooling is 22 ° C, change the set temperature to 25 ° C)
May be.

FIG. 3 is a flowchart of a program for performing the above control. In the figure, p11 to p19 represent each step of the program, and this program is repeatedly executed at predetermined time intervals. The operation is initialized and started at p11, and the battery voltage V is read by the voltage sensor 25 at p12. At p13, it is determined whether or not the battery voltage V is higher than the reference value V1.
If the battery voltage V is larger than the reference value V1, a coefficient Y described later is set to V1 / V in p14, and the process proceeds to p18. If the battery voltage V is smaller than the reference value V1 at p13, it is determined at p15 whether the battery voltage V is larger than the reference value V2 (a value smaller than the reference value V1). If the battery voltage V is larger than the reference value V2, the coefficient Y is set to 1 at p16, and the process proceeds to p18. If the battery voltage V is smaller than the reference value V2, the coefficient Y is set to 0.5 at p17, and the process proceeds to p18.

If the battery voltage V is the reference value V1 at p18, the air conditioner 24
A voltage Vc is obtained by multiplying the voltage X to be applied to the coefficient Y obtained by p14, p16 or p17. .

In the above-described embodiment, the voltage Vc applied to the electric motor or the like for driving the refrigerant compressor C is determined. However, as described above, the duty ratio and frequency of the current applied to the air conditioner 24 or the set temperature chamber of the air conditioner 24 may be used. .

[Effects of the Invention] As described above, the present invention relates to an electric vehicle that uses a battery as a power source, a voltage sensor that detects a voltage of the battery, an electronic control device that receives a voltage detected by the voltage sensor, and the battery. And a motor that drives the refrigerant compressor using the power source as a power source, wherein the electronic control unit reduces the detected voltage of the voltage sensor according to the voltage difference between the detected voltage and the reference value when the detected voltage is lower than the reference value. Since the electric power is applied to the motor, when the battery voltage becomes lower than the reference value, the electronic control unit drives the refrigerant compressor in a stepwise or proportional manner in accordance with the battery voltage decrease amount. Since the voltage or the like applied to the electric motor is reduced, the cooling capacity is reduced, but the deterioration of the vehicle's acceleration performance and climbing performance is suppressed.

 A state in which traveling is impossible due to excessive power consumption is avoided.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device of an electric vehicle including an air conditioner according to the present invention, FIG. 2 is a refrigeration cycle diagram of the air conditioner, and FIG. 3 is a software flow chart of a program of the control device. C: refrigerant compressor, 21: battery, 23: electronic control unit, 24: air conditioner, 25: voltage sensor

Claims (2)

(57) [Claims] 1. An electric vehicle using a battery as a power source, a voltage sensor for detecting a voltage of the battery, an electronic control device for receiving a voltage detected by the voltage sensor, and a refrigerant compressor using the battery as a power source. A driving motor, wherein the electronic control unit applies, to the motor, a power amount reduced according to a voltage difference between the detection voltage and the reference value when the detection voltage of the voltage sensor is lower than a reference value. An air-conditioning control device for an electric vehicle, characterized by: 2. An electric vehicle using a battery as a power source, a voltage sensor for detecting a voltage of the battery, an electronic control device receiving the voltage detected by the voltage sensor, and a refrigerant compressor using the battery as a power source. When the detected voltage of the voltage sensor is lower than a reference value, the electronic control device sets the set temperature during cooling in a normal state in accordance with the voltage difference between the detected voltage and the reference value. An air-conditioning control device for an electric vehicle, wherein the temperature is automatically set higher than a set temperature.