JPH10201281A - Air conditioner - Google Patents

Abstract

(57) [Summary] [Problem] In an air conditioner using a compressor, even if the compressor motor current is shifted in phase and controlled, it hardly contributes to shortening of a heating start-up time, and comfort during a heating operation. Further measures were needed to improve the quality. SOLUTION: One cycle is divided into six steps in an inverter control unit, and in a certain cycle, in a first step, any one of second to sixth steps of a normal six-step 120-degree conduction method energization pattern is used. The energization pattern of the step is output, and in another step, the energization pattern of the 6-step 120-degree energization method is output. In the next cycle, the 6-step 1 is applied in the second step.
The energization pattern of the next step of any one of the second to sixth steps of the energization pattern of the 20-degree energization method is output, and the energization pattern of the six-step 120-degree energization method is output in the other steps. Arm driving signal generating means for generating an arm driving signal by sequentially repeating this procedure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using a compressor, and more particularly to a control method for shortening a heating start-up time.

[0002]

2. Description of the Related Art As a method of increasing the heating capacity of an air conditioner using a compressor, for example, Japanese Patent Application Laid-Open No. 5-27282
There is one disclosed in Japanese Unexamined Patent Publication No. 3 (KOKAI). Hereinafter, a configuration and a control method of this conventional technique will be described with reference to the drawings. FIG. 6 is a configuration diagram of a conventional brushless DC motor driving device disclosed in Japanese Patent Application Laid-Open No. 5-272823. In the figure, reference numeral 1 denotes a commercial AC power supply. The commercial AC power supply 1 is rectified by a rectifier circuit 2 composed of a diode bridge, and is smoothed by a smoothing capacitor 3 to generate a DC voltage VDC. Reference numeral 4 denotes an inverter circuit, which converts a DC voltage VDC into a three-phase AC that drives a three-phase DC brushless motor 5 in response to a control command from the control unit 6.

FIG. 7 shows operation waveforms of various parts of the circuit configured as shown in FIG. 6, wherein the motor back electromotive voltage (phase voltage) VU, phase current iU, effective value current iU (rms) and current phase are advanced. The relationship between the phase current iU ■ and the effective value current iU ■ (rms) at this time is shown. As described above, in the conventional control method, the motor current is increased by shifting the phase of the motor current, and the heat generated by the motor coil due to the increased current is absorbed by the refrigerant as shown in the sectional configuration diagram of the compressor in FIG. This increases the heating capacity.

[0004]

Since the conventional method of controlling an air conditioner is performed as described above, the temperature of the lubricating oil and the refrigerant at the start of heating is low and the temperature of the lubricating oil rises due to the heat generated by the compressor. When the compressor is forced to operate at low capacity, even if the compressor motor current is shifted in phase and controlled, the current increase is small and the heating capacity is hardly improved.

[0005] Even during a defrosting operation with a light load, even if the compressor motor current is shifted in phase and controlled, the amount of increase in the current is small and the heating capacity, that is, the defrosting capacity is hardly improved.

That is, in these sections, the above-mentioned Japanese Patent Application Laid-Open
Even if the control method disclosed in Japanese Patent No. 272823 is used, it is not so effective in shortening the heating start-up time, and further measures are required to improve comfort during the heating operation.

[0007]

An air conditioner according to a first aspect of the present invention is a combination of a compressor for compressing a refrigerant, a three-phase motor housed in the compressor and driving the compressor, and a switching element. An inverter unit that outputs pseudo three-phase AC power and drives the three-phase motor; an inverter control unit that controls the inverter unit;
The cycle is divided into six steps, and in some cycles the first
In the step, the energization pattern of any of the second to sixth steps of the normal 6-step 120-degree energization energization pattern is output, and in the other steps, the 6-step 120-degree energization energization pattern is output. In the next cycle, in the second step, the energization pattern of the step following the one of the second to sixth steps of the energization pattern of the six-step 120-degree energization method is output and the other steps are performed. Includes an arm drive signal generation means for outputting an energization pattern of the 6-step 120-degree energization method and generating an arm drive signal by sequentially repeating this procedure.

The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the three-phase motor is constituted by a DC brushless motor.

According to a third aspect of the present invention, in the air conditioner according to the first aspect, the arm drive signal generating means is configured to perform the energization of the 6-step 120-degree energizing method in a first step in a certain cycle. The energization pattern of the second step in the pattern is output, and the energization pattern of the 6-step 120-degree energization method is output in another step, and the energization pattern of the 6-step 120-degree energization method is output in the second step in the next cycle. The energization pattern of the third step in the pattern is output, and in the other steps, the energization pattern of the six-step 120-degree energization method is output, and this procedure is sequentially repeated to generate the arm drive signal.

According to a fourth aspect of the present invention, in the air conditioner of the first aspect, a voltage value of an energization pattern different from the energization pattern of the six-step 120-degree energization method in the arm drive signal is applied to the six-step 120. This is configured so that the voltage value differs from the voltage value of the current-carrying pattern.

According to a fifth aspect of the present invention, in the air conditioner of the first aspect, the width of the energization pattern different from the energization pattern of the six-step 120-degree energization method in the arm drive signal is set to six steps of 120 degrees. The width is different from the width of the energization pattern of the energization method.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an air conditioner according to Embodiment 1 of the present invention. In the figure, reference numeral 7 denotes a compressor which compresses and circulates a refrigerant into a high-temperature and high-pressure gas state. Reference numeral 8 denotes a four-way valve, which plays a role in changing the circulation direction of the refrigerant. 9 is an outdoor heat exchanger, 10 is an expansion valve,
11 is an indoor heat exchanger and 12 is a thermistor, which detects the temperature of the outdoor heat exchanger 9.

During the cooling operation, the refrigerant flows in the order of the compressor 7, the four-way valve 8, the outdoor heat exchanger 9, the expansion valve 10, the indoor heat exchanger 11, and the compressor 7, as indicated by the solid arrows in FIG. Flows.
During the heating operation, the refrigerant flows in the compressor 7 → the four-way valve 8 → the indoor heat exchanger 11 → the expansion valve 1 as shown by the dotted arrow in FIG.
0 → outdoor heat exchanger 9 → compressor 7

During the cooling operation, the refrigerant compressed to a high-temperature and high-pressure gas state by the compressor 7 is cooled by the outdoor heat exchanger 9 to be in a liquid state. Then, the refrigerant that has been decompressed by the expansion valve 10 and made into a low-temperature and low-pressure liquid state evaporates by absorbing heat from around the indoor heat exchanger 11, becomes a gas state, and is returned to the compressor 7 again. By repeating this cycle, the outdoor side emits heat by blowing outside air to the outdoor heat exchanger 9 with a fan (not shown), and the indoor side sends a fan (not shown) to the indoor heat exchanger 11. It is cooled by blowing air.

During the heating operation, the roles of the outdoor heat exchanger 9 and the indoor heat exchanger 11 during the cooling operation are reversed. In other words, the outdoor side absorbs heat by blowing outside air to the outdoor heat exchanger 9 with a fan (not shown), and the indoor side absorbs heat.
The air is heated by a fan (not shown).

During the heating operation, if the temperature detected by the thermistor 12 is, for example, -5.degree. C. or less, it is determined that the outdoor heat exchanger 9 has much frost, and the four-way valve 8 is switched to perform the cooling operation. 9 (hereinafter, referred to as “frost removing operation”). When the temperature detected by the thermistor 12 becomes, for example, 5 ° C. or higher, it is determined that frost has been removed from the outdoor heat exchanger 9, and the four-way valve 8 is switched to return to the heating operation.

FIG. 2 is a block diagram of a compressor driving device of the air conditioner according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a commercial AC power supply,
Is converted to DC power. Reference numeral 4 denotes an inverter circuit serving as an inverter unit, which converts the DC power into a three-phase AC that drives a three-phase DC brushless motor 5 that is a three-phase motor. The inverter circuit 4 has a configuration in which transistors serving as six switching elements are connected in a three-phase bridge, and a diode (not shown) is connected to each transistor in an anti-parallel manner. Reference numeral 14 denotes a magnetic pole position detection circuit that detects a magnetic pole position of a permanent magnet rotor (not shown) of the DC brushless motor 5. This magnetic pole position detection circuit 14
May be either a sensor type position detection method using a sensor such as a Hall element or a sensorless position detection method that detects a magnetic pole position by an induced voltage or the like. An inverter control circuit 15 is an inverter control unit that outputs arm drive signals UP to WN for controlling the inverter circuit 4 based on the magnetic pole position signal of the magnetic pole position detection circuit 14 from the arm drive signal generation means. The compressor 7 is a DC brushless motor 5
Operating as a drive source.

FIG. 3 is a diagram showing a relationship between energization patterns of arm drive signals UP to WN of the compressor drive unit of the air conditioner according to Embodiment 1 of the present invention and phase currents iU, iV, iW. In the figure, the dotted line indicates the operation waveform during normal operation, and is a case where the DC brushless motor 5 is controlled in an energizing pattern of a 6-step 120-degree energizing method. The solid line shows the DC brushless motor 5 so that the motor efficiency becomes worse.
, The operation waveform of step 4 in the first cycle is output in step (1) of the first cycle, and the energization pattern of step 5 in normal operation is output in step (2) of the next cycle. Then, the DC brushless motor 5 is controlled so that the motor efficiency is deteriorated by partially applying a torque opposite to the rotation direction of the motor. Although not shown in the drawing, in the next cycle, the currents are sequentially shifted such that the energization pattern of step 6 during normal operation is output to step (3).

As described above, by controlling the DC brushless motor 5 with an energization pattern that is not similar to that during normal operation, the motor current can be increased as a whole when the motor speed is not reduced. And
If the position of the energization pattern different from that during normal operation is output as in this case, the motor current can be increased evenly in each phase, and it is also effective as a measure for preventing resonance of sound and vibration.

Further, by changing the amount of voltage when outputting an energizing pattern different from the energizing pattern during normal operation to the amount of voltage when outputting the energizing pattern during normal operation, the current of the compressor motor is increased. Minutes can be adjusted. The heating capacity can be increased by absorbing the motor heat generated by the increased motor current into the refrigerant.

This control method uses the compressor 7 at the start of heating.
This is an effective means even when the vehicle is forced to operate at low capacity or during a defrosting operation with a light load, and shortening the heating start-up time improves the comfort during the heating operation.

In the above-described embodiment, the output of the energization pattern of step 4 during normal operation in step (1) of the first cycle has been described. The same effect can be obtained by outputting a pattern. However, step (1) of the first cycle
The output of the energization pattern in step 2 during normal operation will be described in the following second embodiment.

In the above-described embodiment, the case where the brushless DC motor is used as the drive source of the compressor drive device has been described. Needless to say, the same effect can be obtained.

Embodiment 2 FIG. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 shows energization patterns of arm drive signals UP to WN of a compressor drive device of an air conditioner according to Embodiment 2 of the present invention and phase currents iU, iV,
It is a figure which shows the relationship of iW. In the figure, the dotted line indicates the operation waveform during normal operation, and is a case where the DC brushless motor 5 is controlled in an energizing pattern of a 6-step 120-degree energizing method. The solid line in the first cycle is step (1)
Then, the energization pattern of step 2 during normal operation is output, and the energization pattern of step 3 during normal operation is output in step (2) of the next cycle, and a torque reverse to the rotation direction of the motor is partially applied. 9 is an operation waveform when the DC brushless motor 5 is controlled so that the motor efficiency is deteriorated. Although not shown, in the next cycle, the energization pattern of step 4 in the normal operation is output in step (3) so as to be sequentially shifted.

As described above, by controlling the DC brushless motor 5 with an energization pattern formed by skipping the energization pattern during normal operation, control software can be simplified. Then, as in the first embodiment, the motor current can be increased as a whole when the motor rotation speed is not reduced. When the position of the energization pattern different from that in the normal operation is shifted and output as in this case, the motor current can be increased evenly in each phase, and is also effective as a measure for preventing resonance of sound and vibration. .

Further, by changing the amount of voltage when outputting an energization pattern different from the energization pattern during normal operation to the amount of voltage when outputting the energization pattern during normal operation, the current of the compressor motor is increased. Minutes can be adjusted. The heating capability can be increased by absorbing the motor heat generated by the increase in the motor current into the refrigerant, and the heating start-up time can be reduced, and the comfort during the heating operation can be improved. This is the same as in the first embodiment.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows energization patterns of arm drive signals UP to WN of the compressor drive device of the air conditioner according to Embodiment 3 of the present invention and phase currents iU, iV,
It is a figure which shows the relationship of iW. In the figure, the dotted line indicates the operation waveform during normal operation, and is a case where the compressor motor is controlled by an energization pattern of a 6-step 120-degree energization method.

In the solid line, in step (1), the width of the energization pattern in step 1 during normal operation is shortened, and in step (2), the width of the energization pattern in step 2 during normal operation is output short, and the motor is partially driven. This is an operation waveform when the DC brushless motor 5 is controlled such that the motor efficiency is deteriorated by applying a torque opposite to the rotation direction.

With this configuration, short-circuiting of the transistors in each phase of the inverter circuit 4 can be suppressed.

By controlling the DC brushless motor 5 with an energization pattern that varies the width of the energization pattern during normal operation, the motor current is increased as a whole when the motor rotation speed is not reduced. Can be. When the position of the energization pattern different from that in the normal operation is shifted and output as in this case, the motor current can be increased evenly in each phase, and is also effective as a measure for preventing resonance of sound and vibration. .

Further, by changing the amount of voltage when outputting an energization pattern different from the energization pattern during normal operation to the amount of voltage when outputting the energization pattern during normal operation, the current of the DC brushless motor 5 is changed. The increment can be adjusted. The heating capability can be increased by absorbing the motor heat generated by the increase in the motor current into the refrigerant, and the heating start-up time can be reduced, and the comfort during the heating operation can be improved.

[0032]

The air conditioner according to the first and second aspects of the present invention can reduce the motor current even when the compressor is forced to operate at a low capacity at the start of heating or during a defrosting operation with a light load. The heating capacity is increased by absorbing the motor heat generated by the increase in the current into the refrigerant, thereby shortening the heating start-up time. This makes it possible to improve comfort during the heating operation.

The air conditioner according to the third aspect of the invention has an effect that control software can be simplified in addition to the effect of the first aspect.

In the air conditioner according to the fourth aspect of the present invention, the amount of increase in the current of the compressor motor can be adjusted.
The heating capability can be increased by absorbing the motor heat generated by the increased motor current into the refrigerant.

The air conditioner according to the fifth aspect of the present invention can prevent a short circuit of the switching element of the inverter unit.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram of a compressor driving device of the air conditioner according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a relation between a conduction pattern and a phase current of an arm drive signal of the compressor drive device of the air-conditioning apparatus according to Embodiment 1 of the present invention.

FIG. 4 is a diagram illustrating a relationship between a conduction pattern and a phase current of an arm drive signal of a compressor drive device of an air conditioner according to Embodiment 2 of the present invention.

FIG. 5 is a diagram illustrating a relationship between a conduction pattern and a phase current of an arm drive signal of a compressor drive device of an air conditioner according to Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram of a conventional brushless DC motor driving device.

FIG. 7 is a relationship diagram of a motor back electromotive voltage, a phase current, and an effective value current of a conventional brushless DC motor driving device.

FIG. 8 is a cross-sectional configuration diagram of a conventional compressor.

[Explanation of symbols]

1 commercial AC power supply, 2 rectifier circuit, 3 smoothing capacitor, 4 inverter circuit, 5 brushless DC motor,
6 control unit, 7 compressor, 8 four-way valve, 9 outdoor heat exchanger, 10 expansion valve, 11 indoor heat exchanger, 12 thermistor, 13 converter circuit, 14 magnetic pole position detection circuit, 15 inverter control circuit.

Claims (5)

[Claims] A compressor for compressing a refrigerant; a three-phase motor housed in the compressor for driving the compressor; and a switching element for outputting three-phase AC power to drive the three-phase motor. An inverter unit that controls the inverter unit; and an inverter control unit that controls the inverter unit. The inverter control unit divides one cycle into six steps. The energization pattern of any one of the second to sixth steps of the energization pattern is output, and the energization pattern of the 6-step 120-degree energization method is output in another step, and the second step is performed in the next cycle. In the above 6 step 12
The energization pattern of the step following the one of the second to sixth steps of the energization pattern of the 0-degree energization method is output, and the energization pattern of the 120-degree energization method is output in the other steps in the other steps. An arm drive signal generating means for generating an arm drive signal by sequentially repeating this procedure. 2. The air conditioner according to claim 1, wherein the three-phase motor is constituted by a DC brushless motor. 3. In a certain cycle, the arm drive signal generating means performs the six step 12 in the first step.
The energization pattern of the second step in the energization pattern of the 0-degree energization method is output, and in another step, the energization pattern of the 120-degree energization method is output in the other six steps. In the next cycle, the six steps are performed in the second step. In the energization pattern of the 120-degree energization method, the energization pattern of the third step is output, and in the other steps, the energization pattern of the six-step 120-degree energization method is output, and this procedure is sequentially repeated to generate the arm drive signal. The air conditioner according to claim 1, wherein 4. A configuration in which a voltage value of an energization pattern different from the energization pattern of the 6-step 120-degree energization method in the arm drive signal is different from a voltage value of an energization pattern of the 6-step 120-degree energization method. The air conditioner according to claim 1, characterized in that: 5. A configuration in which the width of an energization pattern different from the energization pattern of the 6-step 120-degree energization method in the arm drive signal is different from the width of an energization pattern of the 6-step 120-degree energization method. The air conditioner according to claim 1, wherein