Abstract: An inverter 6 that drives an electric motor 4 of the electric compressor 3 operates in a protection-against-overheat mode, in which the electric motor is driven at a rotational speed for protection against heat different from a rotational speed specifying value from an air conditioning control unit 20, in order to ensure the flow rate of the refrigerant and cool the inverter itself when the temperature detected by an inverter temperature sensor 22g exceeds a predetermined value. At this time, if the refrigerant pressure increases or the evaporator discharge temperature falls, the air conditioning control unit stops the protection-against-overheat mode operation of the inverter and directs the inverter to forcedly stop the electric motor. Due to this, an excessive increase in the refrigerant pressure and evaporator freezeing can be prevented, and thus the function of the refrigerating cycle can be protected.

Abstract: In an air conditioner for a vehicle, when a target rotation speed of an electric compressor calculated by a target rotation speed calculating means is higher than an upper limit set by an upper limit setting means and a noise level is reduced from a level equal to or higher than a predetermined noise level to a level lower than the predetermined noise level, an inverter controls the compressor to stop for a predetermined period of time and subsequently increase rotation speed to the upper limit. Since the compressor is stopped for the predetermined period of time, the rotation speed of the compressor is controlled without detecting a rotational position of the compressor. Therefore, when the target rotation speed is higher than the upper limit and the noise level is decreased lower than the predetermined noise level, an actual rotation speed of the compressor is immediately decreased.

Abstract: In a fluid heating apparatus, a heat protect temperature sensor indirectly detects temperature of fluid heated by an electric heater adjacent to the electric heater. Also, a heated fluid sensor detects the temperature of the fluid adjacent to a fluid inlet of a heat exchanger. When it is determined that the temperature difference between the detected temperatures exceeds a predetermined level, electric power supply to the electric heater is discontinued. Thus, boil-dry is restricted early with a simple means.

Abstract: In a hybrid vehicle air conditioning system in which coolant is supplied to a heater core from a vehicle running engine, for heating, a demand of the operation of the vehicle running engine is controlled to obtain respective set coolant temperatures TWS2 for target air-outlet temperature TAO of air sent out into a passenger compartment during a bilevel mode operation and TWS1 for the target air-outlet temperature TAO during a foot mode operation by setting the set coolant temperature TWS2 higher than the set coolant temperature TWS1.

Abstract: In a vehicle air conditioner, a controller calculates a first target post-evaporator temperature for defogging a windshield based on a detection humidity of a humidity sensor, and calculates a second target post-evaporator temperature for defogging the windshield regardless of the detection humidity of the humidity sensor. Then, the controller determines a smaller one between the first and second target post-evaporator temperatures, as a target post-evaporator temperature. Accordingly, even when the humidity sensor detects a humidity lower than an actual humidity of a passenger compartment when a blower operates by a low air-blowing amount, a windshield is prevented from fogging.

Abstract: In a battery cooling system that cools a battery by using conditioned air (inside air of a passenger compartment) of a vehicle air conditioner, a battery control unit controls a battery blower to increase an air amount supplied to the battery when a predetermined condition is satisfied. In contrast, an air-conditioning control unit decreases a compression capacity of a compression device after an air amount supplied to the battery is increased to a predetermined amount by the battery control unit. For example, the air-conditioning control unit decreases the compression capacity of the compression device after a predetermined time passes after the air amount supplied to the battery is increased to the predetermined amount. Accordingly, the temperature inside the passenger compartment and the compression device can be stably controlled.

Abstract: In an air conditioner, a target compressor rotation speed is determined based on a target air temperature, which represents an air conditioning load, when an electric compressor is started from a stop state. Thus, an evaporator air temperature can be approximated to a target evaporator air temperature, more quickly as compared with a control method where an incremental rotation speed is added to a present rotation speed of the electric compressor, that is, 0 rpm. Accordingly, a large cooling capacity can be obtained for a short time period. Thus, an air temperature in a compartment can be quickly reduced to a comfortable temperature, when the air conditioner is started, for example.

Abstract: In an air conditioner for a vehicle, when a target rotation speed of an electric compressor calculated by a target rotation speed calculating means is higher than an upper limit set by an upper limit setting means and a noise level is reduced from a level equal to or higher than a predetermined noise level to a level lower than the predetermined noise level, an inverter controls the compressor to stop for a predetermined period of time and subsequently increase rotation speed to the upper limit. Since the compressor is stopped for the predetermined period of time, the rotation speed of the compressor is controlled without detecting a rotational position of the compressor. Therefore, when the target rotation speed is higher than the upper limit and the noise level is decreased lower than the predetermined noise level, an actual rotation speed of the compressor is immediately decreased.

Abstract: In a compressor control system for a vehicle air conditioner, a hybrid ECU of the vehicle controls a rotation speed of a compressor electric motor. In this case, an output circuit, which outputs a driving signal for driving the compressor electric motor, only needs to be newly provided in the hybrid ECU when a hybrid vehicle or an electric vehicle is manufactured based on an engine vehicle. Therefore, a high cost is not caused even when the output circuit is provided in the hybrid ECU which should be newly designed and manufactured. In addition, because the output circuit does not need to be provided in an air-conditioning ECU which is an existing component of the engine vehicle, the air-conditioning ECU in the engine vehicle can be directly applied to that in the hybrid vehicle without a substantial hardware change. Therefore, design cost can be reduced.

Abstract: An air-conditioner is operated under one mode selected from among three modes, i.e., a cooling mode, a heating mode and an air-mixing mode. Conditioned air temperature is controlled by changing a cooling ability in the cooling mode, a heating ability in the heating mode, and a position of an air-mixing door in the air-mixing mode. When the operating mode is switched to the cooling mode or to the heating mode from another mode, the position of the air-mixing door is gradually changed to prevent an abrupt temperature drop or rise until a difference between a target temperature and an actual temperature becomes smaller than a predetermined value.

Abstract: In a fluid heating apparatus, a heat protect temperature sensor indirectly detects temperature of fluid heated by an electric heater adjacent to the electric heater. Also, a heated fluid sensor detects the temperature of the fluid adjacent to a fluid inlet of a heat exchanger. When it is determined that the temperature difference between the detected temperatures exceeds a predetermined level, electric power supply to the electric heater is discontinued. Thus, boil-dry is restricted early with a simple means.

Abstract: In a vehicle air-conditioning system, a supply of electric power to a first electric heater and a supply of electric power to a second electric heater are duty controlled at the same duty ratio in such a manner that the supply of the electric power to the second electric heater is phase shifted by one half of a period from the supply of the electric power to the first electric heater.

Abstract: A vehicle air-conditioning system limits electric power used by an electric motor for a compressor in a prescribed fashion that quickly removes fog from the windows when a defroster mode is selected. When the defroster mode is selected, the limit on the electric power used by the electric motor is lifted, and the number of revolutions of the compressor is set to a high level to raise the dehumidifying and cooling capability to quickly remove moisture from the windows.

Abstract: A power supply control apparatus is provided for a vehicle that includes air-conditioning electric devices and other electric devices. In the power supply control operation, current target power that is necessary for the specific electric device is calculated based on precedent target power calculated last time; allowed power that is allowed to be supplied to a specific electric device is calculated based on total power demand of the vehicle; power to be supplied to the specific device to the allowed power if the current target power is larger than the allowed power; and the precedent target power is replaced with the allowed power if actual power supplied to the specific electric device is limited to the allowed power.

Abstract: A vehicle air-conditioning system limits electric power used by an electric motor for a compressor in a prescribed fashion that quickly removes fog from the windows when a defroster mode is selected. When the defroster mode is selected, the limit on the electric power used by the electric motor is lifted, and the number of revolutions of the compressor is set to a high level to raise the dehumidifying and cooling capability to quickly remove moisture from the windows.

Abstract: In a vehicle air conditioner, a control unit includes determining means for determining a first start of a compressor for compressing refrigerant in a refrigerant cycle after being mounted on the vehicle, and control means for controlling operation of the compressor so that the compressor is operated for a predetermined time by a rotation speed equal to or lower than a predetermined rotation speed when the determining means determines the first start of the compressor. Accordingly, breaking-in operation of the compressor can be accurately performed for the predetermined time by an automatic control.

Abstract: In a vehicle air conditioner, a control unit includes determining means for determining a first start of a compressor for compressing refrigerant in a refrigerant cycle after being mounted on the vehicle, and control means for controlling operation of the compressor so that the compressor is operated for a predetermined time by a rotation speed equal to or lower than a predetermined rotation speed when the determining means determines the first start of the compressor. Accordingly, breaking-in operation of the compressor can be accurately performed for the predetermined time by an automatic control.

Abstract: In a hybrid vehicle including an engine and an electric motor both for running the vehicle, an air conditioner includes a compressor driven by the engine, and an engine controller controls the operation of the engine based on a condition of the air conditioner and a condition of the vehicle except the air conditioner. While the air conditioner performs a defrosting control for a windshield, the engine controller drives the engine irrespective of the condition of the vehicle except the air conditioner. On the other hand, when the defrosting control is not performed, the operation of the engine is controlled in accordance with the condition of the vehicle, for example.

Abstract: In a vehicle having a battery and a generator, when a residual charge amount of the battery is reduced to a first predetermined amount, a power-generation command is output to a generator, and the battery is charged by the generator driven by an engine. When the residual charge amount is reduced to a second predetermined amount lower than the first predetermined amount, plural air-conditioning electrical devices are stopped. Thereafter, when the residual charge amount of the battery is increased to be larger than the second predetermined amount, the electrical devices are started at different start times.

Abstract: In an air conditioner for a hybrid vehicle, when a residual charging degree of a battery becomes equal to or lower than a target degree, the electrical motor generator is driven by a vehicle engine so that the battery is charged through the electrical motor generator. When the engine is driven, the target degree of the battery is set higher than that when the engine is stopped so that a charging operation tends to be required while the engines driven. Accordingly, the frequency for starting the engine only for charging the battery is reduced.