JP2001197788A - Air conditioning system for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning system for an automobile, capable of rapidly rotating a motor operated compressor even at low speed rotation of an engine. SOLUTION: The air conditioning system for the automobile comprises a rectifier for rectifying an AC output of a generator driven by the engine to obtain DC power, a DC voltage detector for detecting the voltage of a DC power line, a reversible chopper arranged parallel to the line and a battery changing and discharging, and an inverter for converting the DC power into an AC power having a predetermined frequency and voltage. The chopper charges the battery as a step-down chopper when the DC voltage detector detects the voltage in a predetermined range, and discharges the battery as a step-up chopper when the DC voltage detector detects the voltage in a predetermined range or lower. The battery is used as an auxiliary energy source when the rotating speed of the engine is abruptly decelerated or when the speed of the engine is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an all-electric vehicle, and more particularly to an air conditioner capable of exhibiting a sufficient cooling capacity even when an engine is running at a low speed.

[0002]

2. Description of the Related Art Conventionally, an all-electric vehicle air conditioner which operates by the power generated by a generator driven by an output shaft of an engine converts an output of a generator 2 into a direct current by a rectifier 3 as shown in FIG. The inverter 5 converts the voltage into alternating current of a predetermined frequency and voltage to supply the electric power required by the electric compressor 6.

[0003]

However, in the above-mentioned method, if the electric compressor operates at a high speed when the engine speed decreases and the power generation capacity of the generator decreases, the generator becomes overloaded. There was a problem of becoming.

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and is provided with a reversible chopper device and a battery in a DC line so that an electric compressor can be rotated at a high speed even at a low engine speed. It is intended to provide an air conditioner.

[0005]

According to the present invention, there is provided an air conditioner which operates on the power generated by a generator driven by an output shaft of an engine, wherein the AC output of the generator is rectified. A rectifier for obtaining DC power, a DC voltage detection unit for detecting a voltage of the DC power line, a reversible chopper device arranged in parallel with the DC power line, and an output side of the reversible chopper device, A battery that performs charging and discharging under the control of the reversible chopper device, an inverter that converts the DC power into AC power having a predetermined frequency and voltage, and an electric compressor driven by an output of the inverter. And a vehicle air conditioner.

According to a second aspect of the present invention, in the vehicle air conditioner according to the first aspect, the reversible chopper device is configured as a step-down chopper when the DC voltage detector detects a voltage higher than a predetermined range. The reversible chopper device performs an operation of charging a battery, and performs an operation of discharging the battery as a boost chopper when the DC voltage detection unit detects a voltage that is equal to or less than a predetermined range.

According to a third aspect of the present invention, in the vehicle air conditioner according to the first or second aspect, the battery is used as an auxiliary energy source when the rotational speed of the engine suddenly decreases. It is characterized by.

According to a fourth aspect of the present invention, in the vehicle air conditioner according to the first or second aspect, the battery is used as an auxiliary energy source when the rotation speed of the engine is low. It is characterized by.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an automotive air conditioner according to one embodiment of the present invention. In this figure, reference numeral 1 denotes an automobile engine, which is a power source for traveling and also drives a generator 2 for an air conditioner. Rectifier 3 converts AC output of generator 2
, And is converted into AC power of a predetermined frequency and voltage by the inverter 5 to drive the electric compressor 6.

Further, a reversible chopper device 7 is arranged in parallel with the line converted into a direct current by the rectifier 3, and a battery 8 is connected to the output side of the reversible chopper device 7. The reversible chopper device 7 switches between charging and discharging of the battery 8 and controls the amount of charge or discharge. The DC voltage detector 9 detects the voltage of the DC line, controls the reversible chopper device 7 based on the detection result, and controls charging or discharging of the battery 8.

The operation of the air conditioner for a vehicle having such a configuration will be described with reference to FIG. 1 and FIG. 2 showing the internal circuit of the reversible chopper device 7. First, when the rotation of the engine 1 is at high speed, the generated voltage of the generator 2 is high, and the outputable power is also large. Therefore, the DC voltage on the output side of the rectifier 3 also increases. At this time, the power required by the electric compressor 6 is supplied by the AC power obtained by converting the DC power into a predetermined frequency and voltage by the inverter 5.

If the DC line voltage is high and the battery 8
Is not fully charged, it detects that the battery 8 can be charged by the detection voltage of the DC voltage detection unit 9, switches the transistor 11 of the reversible chopper device 7, and charges the battery 8 via the reactor 15. The value of the charging current is controlled by controlling the ON period of the transistor 11, and the reversible chopper device 7 operates as a step-down chopper.

Next, the rotation of the engine 1 becomes slow,
When the DC voltage falls below the specified range, the power charged in the battery 8 by the reversible chopper device 7 is boosted and discharged and supplied to the DC line, which is used as the input power of the inverter 5. The operation at this time is as follows.
And the transistor 12 is turned on
N, the current of the battery 8 is
And discharge through the transistor 12, at which time energy is stored in the reactor 15. Transistor 12 is set to O
When the FF is performed, a voltage due to the back electromotive force is generated in the reactor 15, and the voltage of the battery 8 and the voltage due to the back electromotive force of the reactor 15 are added and applied to the DC line via the diode 13, thereby performing the operation of the boost chopper. .

As transistors 11 and 12, IG
BT or the like is preferably used. By interposing the reversible chopper device between the DC line and the battery as described above, the battery can be charged and discharged even when the DC line voltage and the battery voltage are different.

The operation of one embodiment of the present invention has been described above in detail with reference to the drawings. However, the present invention is not limited to this embodiment, and a design change or the like may be made without departing from the gist of the present invention. The present invention is also included in the present invention. For example, in the above embodiment, the generator and the rectifier have been described as being uncontrolled, but may be a generator and a rectifier that perform voltage control, respectively.

[0016]

As described above, according to the present invention, when the generated power is large, the battery is charged, and when the generated power is small, the battery is supplemented with the discharged power to input to the electric compressor. Since the power to be generated is controlled, an effect that a small generator can be used can be obtained. In addition, even when the engine speed suddenly drops, electric power is replenished from the battery, so that the electric compressor can be operated with a sufficient output, and the effect that the comfort in the company can be maintained can be obtained. Can be

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an automotive air conditioner according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of the reversible chopper device of FIG.

FIG. 3 is a block diagram showing a configuration of a vehicle air conditioner according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Generator 3 ... Rectifier 4 ... Smoothing capacitor 5 ... Inverter 6 ... Electric compressor 7 ... Reversible chopper device 8 ... Battery 9 ... DC voltage detection part 11, 12 ... Transistor 13, 14 ... Diode 15 ... Reactor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H590 AA03 CA07 CA23 CC01 CD01 CD03 CD10 CE05 CE10 EA07 EB02 EB07 FA08 FC12 FC23 FC26 GA02 GA09 HA02

Claims (4)

[Claims] 1. An air conditioner that operates on power generated by a generator driven by an output shaft of an engine, comprising: a rectifier that rectifies an AC output of the generator to obtain DC power; and a voltage of the DC power line. A reversible chopper device disposed in parallel with the DC power line, a battery connected to the output side of the reversible chopper device, and performing charging and discharging under the control of the reversible chopper device. An inverter that converts the DC power into AC power having a predetermined frequency and voltage; an electric compressor driven by an output of the inverter;
An air conditioner for a vehicle, comprising: 2. The reversible chopper device performs an operation of charging the battery as a step-down chopper when the DC voltage detector detects a voltage higher than a predetermined range. The vehicle air conditioner according to claim 1, wherein when detecting a condition, an operation of discharging the battery is performed as a step-up chopper. 3. The vehicle air conditioner according to claim 1, wherein the battery is used as an auxiliary energy source when the rotation speed of the engine suddenly decreases. 4. The vehicle air conditioner according to claim 1, wherein the battery is used as an auxiliary energy source when the rotation speed of the engine is low.