JP3441852B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an air conditioner that performs a defrost operation.

[0002]

2. Description of the Related Art Conventionally, in a heat pump type air conditioner that performs cooling and heating operation, during heating operation, as shown in the Mollier diagram of FIG. 13 , the outdoor heat exchanger used as an evaporator is at a low pressure side and The indoor heat exchanger used as a heat exchanger is on the high pressure side, and the heat taken from the outside by the outdoor heat exchanger is released into the room by the indoor heat exchanger for heating. During this heating operation, especially when the outside air temperature is low, frost adheres to the low temperature outdoor heat exchanger, and the heat exchange efficiency deteriorates,
Heating performance is significantly reduced. Therefore, in the above air conditioner, when frost adheres to the outdoor heat exchanger, the heating cycle is switched to the cooling cycle, the outdoor heat exchanger is set to the high pressure side as a condenser, and the temperature of the outdoor heat exchanger is increased. After defrosting and removing the attached frost, the heating cycle is switched to the heating cycle again to perform the heating operation.

[0003]

[SUMMARY OF THE INVENTION Incidentally, the air conditioner, since during the defrost operation is that the cold air stops the indoor fan so as not blown out from the indoor unit, as shown in FIG. 1 4, the indoor heat exchanger The cooling capacity of the (evaporator) becomes low, and the heat radiation amount of the outdoor heat exchanger, which is the condenser, also becomes small. Therefore, there is a drawback that the heat source for raising the temperature of the outdoor heat exchanger is insufficient and the defrost time becomes long. Therefore, the longer the defrost time, the lower the heating capacity, and the lower the room temperature, which is uncomfortable.

Therefore, an object of the present invention is to provide an air conditioner capable of shortening the defrost time by operating the compressor motor at low efficiency during the defrost operation.

[0005]

Means for Solving the Problems] To achieve the above object, an air conditioner according to claim 1, a motor for driving the compressors, and an inverter for switching the pattern of the voltage applied to the armature coil of the motor In the air conditioner equipped with the above, when the motor is operated with high efficiency based on the change in the voltage level at the neutral point of the armature coil,
The voltage level at the neutral point of the armature coil is at the high efficiency level.
The inverter output phase or output voltage
When controlling the pressure while operating the motor with low efficiency
Is when the voltage level at the neutral point of the armature coil is low
The control means for controlling the phase or output voltage of the output of the above-mentioned inverter is provided so that the level becomes .

According to the air conditioner of the first aspect, in the heating operation and the defrosting operation, for example, the control means controls the output of the inverter based on the change in the voltage level of the neutral point of the armature coil. Thus, the motor for driving the compressor is operated so as to have high efficiency during the heating operation and low efficiency during the defrost operation. In other words, when there is a correlation between the voltage at the neutral point of the armature coil of the motor and the motor efficiency, the voltage level at the neutral point of the armature coil during heating operation becomes the level at the time of high efficiency. In addition, by controlling the phase or output voltage of the output of the inverter, while operating the motor with high efficiency, during defrost operation, the voltage level of the neutral point of the armature coil becomes the level at the time of low efficiency, By controlling the output phase or output voltage of the inverter,
The motor operates at low efficiency. In the defrost operation, when the motor of the compressor is operated at low efficiency, the motor current increases and the armature coil of the motor generates heat, so the heat equivalent of the work of the compressor increases and the discharge of the compressor is increased. The temperature of the refrigerant rises.

Therefore, by operating the motor of the compressor with low efficiency, the amount of heat for defrosting increases and the defrosting time can be shortened.

The air conditioner of claim 2 is the same as that of claim 1.
In the air conditioner, the control means includes an operation mode selection means that selectively selects the high-efficiency operation mode and the low-efficiency operation mode and also selects the low-efficiency operation mode during defrost operation. I am trying.

According to the air conditioner of the second aspect , at the time of defrost operation, the operation mode selection means of the control means selects the low efficiency operation mode, so that the motor current increases and the armature coil generates heat, The heat equivalent of work of the compressor increases, and the temperature of the refrigerant discharged from the compressor rises.

Therefore, during defrost operation, the motor is operated at low efficiency to raise the temperature of the refrigerant discharged from the compressor to supplement the heat source for defrost, so that the defrost time can be shortened and the indoor comfort is improved. To do.

The air conditioner of claim 3 is the same as that of claim 1.
In the air conditioner, the control means includes an operation mode selection means that selectively selects the high-efficiency operation mode and the low-efficiency operation mode and also selects the low-efficiency operation mode when the heating operation is started. It is characterized by that.

According to the air conditioner of the third aspect, when the heating operation is started, the operation mode selection means of the control means selects the low efficiency operation, so that the motor current increases and the armature coil generates heat. Therefore, the heat equivalent of the work of the compressor increases, and the temperature of the discharged refrigerant rises.

Therefore, when the heating operation is started up, the temperature of the refrigerant discharged from the compressor is raised by operating the motor with low efficiency, and even when the compressor is at a low temperature due to the long stop time, the heating start-up is performed. The blowing temperature of the indoor unit at the time of raising the temperature can be quickly raised, and the indoor comfort is improved.

The air conditioner of claim 4 is the same as that of claim 1.
In the air conditioner according to any one of 1 to 3, the control means detects a relative rotational position between the rotor and the stator of the motor and outputs a position signal, and a rotational position detection means. Phase correction means for correcting the phase from the time when the position signal is switched to the time when the voltage pattern is switched is provided.

According to the air conditioner of the fourth aspect , the rotational position detecting means of the control means detects the relative rotational position between the rotor and the stator of the motor of the compressor,
Output position signal. When the rotational frequency is controlled by adjusting the output voltage of the inverter, the phase correction means of the control means controls the phase from the time when the position signal is switched to the time when the voltage pattern is switched so as to achieve high efficiency. While compensating for low efficiency,
The phase from the time when the position signal is switched to the time when the voltage pattern is switched is advanced and corrected to the phase side rather than when the efficiency is high.

Therefore, by correcting the phase of the output of the inverter by the rotational position detecting means and the phase correcting means, while smoothly rotating the motor of the compressor,
The motor can be operated with high efficiency or low efficiency.

The air conditioner of claim 5 is the same as that of claim 1.
The air conditioner according to any one of 1 to 3 is characterized in that the control means includes voltage correction means for correcting the output voltage of the inverter in order to control the output of the inverter.

According to the air conditioner of the fifth aspect , when the rotational frequency is controlled by adjusting the phase of the output of the inverter, the voltage correction means of the control means outputs the output of the inverter so as to have high efficiency. While correcting the voltage,
The output voltage of the inverter is corrected to a voltage lower than that at the time of high efficiency so that the efficiency becomes low.

Therefore, by correcting the output voltage of the inverter by the voltage correction means, it is possible to operate the motor of the compressor with high efficiency or low efficiency while smoothly rotating the motor of the compressor.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The air conditioner of the present invention will be described in detail below with reference to the embodiments shown in the drawings .

FIG. 1 shows the structure of the essential parts of an air conditioner according to an embodiment of the present invention , in which 1 is an armature coil 1a, 1a.
Rotor 1 in which b and 1c are Y-connected and have a plurality of permanent magnets
0 is rotated by a rotating magnetic field, 2 is the armature
Connected in parallel with the coils 1a, 1b, 1c, the resistors 2a, 2
Resistor circuit in which b and 2c are connected in Y
The voltage at the neutral point V _M and the voltage at the neutral point of the armature coils 1a, 1b, 1c
The potential difference signal V _MN representing the potential difference from the pressure V _N is detected,
Based on the potential difference signal V _MN , the relative rotation of the rotor 10
A position that detects the position and represents the relative position of the rotor 10.
Rotational position detection as rotational position detection means for outputting position signal
The output device 4 receives the position signal from the rotational position detector 3 described above.
As a control means for outputting a switching signal.
The controller 5 receives the switching signal from the microcomputer 4 described above.
The base drive circuit outputs a commutation control signal.
The commutation control signal from the base drive circuit 5 is converted into an inverter.
I am entering in 20 respectively. In addition, the stator 1 and the rotor
10 constitutes a brushless DC motor 11.

The rotational position detector 3 is composed of the amplifier IC1.
Input voltage V _M at the neutral point of the resistor circuit 2 to the non-inverting input terminal
In addition, the resistor R ₁ is connected to the inverting input terminal of the amplifier IC1.
Then connect the ground GND and connect to the output of amplifier IC1.
A differential amplifier 31 having a resistor R ₂ connected between it and the input terminal
And a resistor whose one end is connected to the output of the differential amplifier 31.
Connected between the other end of R ₃ and its resistor R ₃ and ground GND
Integrator 32 consisting of the generated capacitor C ₁ and the product
The other end of the resistor R ₃ of the divider 32 is connected to the non-inverting input terminal.
And an amplifier with ground GND connected to the inverting input terminal
It is equipped with a zero cross comparator 33 composed of IC2.
It And the neutral point of the armature coils 1a, 1b, 1c
Is the inverting input of the differential amplifier 31 via the ground GND.
Since the differential amplifier 31 is connected to the terminals,
In neutral voltage V _M of path 2 and in armature coils 1a, 1b, 1c
The potential difference signal V _MN representing the potential difference from the sex point voltage V _N is detected.
Put out.

The inverter 20 has an AC power source 9
A die for full-wave rectification of AC voltage connected to both output terminals of
Diode bridge 1 consisting of odes D ₁ , D ₂ , D ₃ and D ₄
2 and the positive output terminal of the diode bridge 12
The reactor L with one end connected, and the reactor L
The other end is connected to one end, and the other end is connected to the diode bridge 12
A capacitor C ₀ which is connected to the negative output terminal of con
Three collectors each having a collector connected to one end of the capacitor C ₀
Transistors 20a, 20b, and 20c, the other end of the capacitor C ₀
Three transistors 20d, each of which has an emitter connected to
It is composed of 20e and 20f. The transistor 2
The emitter of 0a and the collector of transistor 20d are connected to each other.
Connect to the emitter of transistor 20b and the transistor
The collectors of 20e are connected to each other,
Connect the emitter and collector of transistor 20f to each other
is doing. In addition, the transistors 20a and 20d are connected to each other.
Connect the U-phase armature coil 1a to the part connected to
V is connected to the connected parts of the transistors 20b and 20e.
Connect the armature coil 1b of the phase and connect the transistors 20c, 2
W-phase armature coil 1c is connected to the 0f
Connected. Then, each of the transistors 20a-2
Reverse the diode between the collector and emitter of 0f.
They are connected in parallel. In addition, the reactor L and the condenser
A smoothing circuit is constructed by C ₀ , and this smoothing circuit
Smooths the full-wave rectified pulsating voltage from the bridge 12.
The DC voltage is set to the specified value. Further, the air conditioner includes level detectors A and B that receive the integrated signal from the integrator 32 of the rotational position detector 3 and output the level detection signals to the microcomputer 14, respectively.

As shown in FIG. 2 , the level detector A has an integrated signal ∫V from the integrator 32 of the rotational position detector 3.
Connect _MN dt to the inverting input terminal of amplifier IC3,
The non-inverting input terminal of the amplifier IC3 is connected to the ground GND via the resistor R4, and the resistor R5 is connected between the output terminal of the amplifier IC3 and the non-inverting input terminal. The amplifier IC3 and the resistors R4 and R5 form a hysteresis comparator having a hysteresis characteristic. The level detector B connects the integrated signal ∫V _MN dt from the integrator 22 of the rotational position detector 3 to the inverting input terminal of the amplifier IC3, and also connects the non-inverting input terminal of the amplifier IC3 to the ground GN.
D is connected through a resistor R6, and the output terminal of the amplifier IC3 and the non-inverting input terminal are connected through a resistor R7. The amplifier IC3 and the resistors R6 and R7 form a hysteresis comparator having a hysteresis characteristic.

FIG. 3 is a block diagram of the microcomputer 14.
It is shown that this microcomputer 14 is the rotational position detector 3
The position signals from these are connected via an external interrupt terminal.
Upon receiving the positive timer T1 and the position signal, the armature coil
Period measurement to measure the period of 1a, 1b, 1c voltage pattern
The timer T2 and the measured time from the period measuring timer T2.
, The armature coils 1a, 1b,
Calculate the cycle of the voltage pattern of 1c, and
A period calculation unit 41 that outputs a period signal, and a period calculation unit 41
Corresponding to the phase correction angle from that period
Calculate the timer value to
And a timer value calculator 42 that outputs a value setting signal.
It Further, the microcomputer 4 is a phase correction timer T1
Outputs a voltage pattern signal in response to the interrupt signal IRQ from
The inverter mode selection unit 43 and the period calculation unit 41
It receives the periodic signal from the
From the speed calculation unit 44 that outputs the signal
By receiving the current speed signal and the speed command signal from the outside,
The speed controller 45 that outputs the pressure command signal and the inverter
Voltage pattern signal from the mode selector 43 and the speed controller 4
Receives voltage command signal from 5 and outputs switching signal
And a PWM (Pulse Width Modulation) unit 46 for inputting. Na
The above phase correction timer T1, cycle measurement timer T2, cycle performance
The phase correction means is configured by the calculation unit 41 and the timer value calculation unit 42.
Is made.

Further , the microcomputer 14 has a switch SW in which the level detection signal 1 from the level detector A is input to the input terminal 1 and the level detection signal 2 from the level detector B is input to the input terminal 2. The level determination unit 101 to which either one of the level detection signal 1 and the level detection signal 2 from the switch SW is input, and the switch SW.
And a driving mode command unit 102 that outputs a switching signal.

[0027] The brushless DC motor 11 is driven in accordance with the position signal, as shown in FIG. 4, level detector A
Signal ∫ input to the inverting input terminal of the amplifier IC3
When V _MN dt (shown in FIG. 4 (A)) exceeds the reference value E1, the output terminal of the amplifier IC3 becomes L level, and the integrated signal ∫V _MN dt
Becomes less than the reference value E2, the output terminal of the amplifier IC3 becomes H
It becomes a level. That is, the level detection signals (shown in FIG. 4 (C)) of the level detectors A and B are signals of the same cycle and different in phase from the position signal (shown in FIG. 4 (B)). However, when the level of the integrated signal ∫V _MN dt from the rotational position detector 3 decreases, the integrated signal ∫V _MN does not exceed the reference value E1 or the integrated signal ∫V _MN dt does not become less than the reference value E2. As a result, the level detection signal has a lower frequency and a different duty ratio than the position signal. That is, whether or not the integrated signal ∫V _MN is equal to or higher than a predetermined level can be detected by whether or not the level detection signal continues in a predetermined cycle. In the high-efficiency operation mode described later, the reference values E1 and E of the level detector A can be determined so that it can be determined whether the integrated signal ∫V _MN is equal to or more than the first predetermined value.
In addition to setting 2, the reference value of the level detector B is set so that it can be determined whether the integrated signal ∫V _MN is the second predetermined value or more in the low efficiency operation mode described later.

[0028] Hereinafter, FIGS an operation of the microcomputer 14,
It will be described according to the flowcharts 7 , 8 , and 9 . It should be noted that the interrupt process 21 is performed every time the position signal input to the external interrupt terminal of the microcomputer 14 rises or falls.

[0029] First, in FIG. 5, when the interrupt process 21 is started, the phase correction timer T1 (FIG. 5 in step S300
Then, it is determined whether the timer T1 is counting),
If it is determined that the timer T1 is counting, the process proceeds to step S331 and the timer T1 is stopped. That is, when the timer T1 is counting, in preparation for the next start,
The timer T1 is stopped. Next, the voltage pattern is output in step S332, and the process proceeds to step S301. On the other hand, if it is determined in step S300 that the timer T1 is not counting, the process proceeds to step S301.

Next, in step S301, it is determined whether or not a defrost operation command has been issued. If it is determined that a defrost operation command has been issued, the process proceeds to step S333 and the level detector B is detected.
After reading, the process proceeds to step S302. On the other hand, if it is determined in step S301 that the defrost operation command has not been issued, the process proceeds to step S334, the level detector A is read, and then the process proceeds to step S302. That is, during normal operation,
The switch SW is switched to the input 1 side by the switching signal of the operation mode command unit 102 to select the level detection signal 1 from the level detector A, while the defrost operation is performed.
Switch SW by the switching signal of the operation mode command unit 102
Is switched to the input 2 side, and the level detection signal 2 from the level detector B is selected.

Next, in step S302 shown in FIG. 6 ,
If it is determined whether the previous level detection signal is the H level and the previous level detection signal is the H level, step S32
In step 1, it is determined whether or not the current level detection signal is L level. Then, if it is determined in step S321 that the current level detection signal is L level, the process proceeds to step S322, and the counter CNT1 is incremented by 1, while if it is determined that the current level detection signal is not L level, the process proceeds to step S303.

On the other hand, if it is determined in step S302 that the previous level detection signal is not at the H level, the process proceeds to step S323 to determine whether the current level detection signal is at the H level.
When it is determined in step S323 that the current level detection signal is the H level, the process proceeds to step S324 and the counter CN
On the other hand, if it is determined that the current level detection signal is not at H level while T1 is incremented by 1, the process proceeds to step S303.

Next, in step S303, the counter C
NT2 is incremented by 1, and the process proceeds to step S304. Then, it is determined whether or not the counter CNT2 at the step S304 is 2, when it is determined that the counter CNT2 is 2, the process proceeds to step S325. In step S325, the counter CNT2 is 2 is not satisfied that, step S305 shown in FIG. 7 Proceed to. Next, in step S325, it is determined whether or not the counter CNT1 is 2, and when it is determined that the counter CNT1 is 2, the process proceeds to step S326, and the previous phase correction angle command is set to + 1d.
As eg (delay correction side), the process proceeds to step S329. on the other hand,
If it is determined in step S325 that the counter CNT1 is not 2, the process proceeds to step S327, and it is determined whether or not the counter CNT1 is 0. Then, when it is determined that the counter CNT1 is 0 in step S327, step S328 is performed.
In step S329, the previous phase correction angle command is set to −1 deg (advance correction side). On the other hand, if it is determined in step S327 that the counter CNT1 is not 0, step S32
Go to 9. Next, in step S329, the counter CNT1 is cleared, the process proceeds to step S330, the counter CNT2 is cleared, and the process proceeds to step S305. It should be noted that before the first interrupt processing 21 is started, an initial value is set in the phase correction angle command and the counters CNT1 and CNT2 are cleared.

Next, in step S305 shown in FIG. 7 ,
It is determined whether or not the correction angle (phase correction angle based on the phase correction command signal from the level determination unit 101) is 60 deg or more. If the correction angle is 60 deg or more, the process proceeds to step S341, and the correction angle is 120 deg. It is determined whether or not the above. Then, if the correction angle is 120 deg or more in step S341, the process proceeds to step S342, the phase correction E (correction E in FIG. 7 ) is made, and the process proceeds to step S343. Then, step S34
In 3, it is determined whether the previous time is the phase correction C (correction C in FIG. 7 ) or the phase correction D (correction D in FIG. 7 ), and it is determined that the previous time is the phase correction C or the phase correction D. Then,
After the correction switching request is made in step S344, the process proceeds to step S306. On the other hand, if it is determined in step S343 that the previous time is not the phase correction C or the phase correction D, the step S343
Proceed to 306.

On the other hand, in step S341, the correction angle is 120 deg.
If it is less than this, the process proceeds to step S345, the phase correction D is performed, and the process proceeds to step S346. Then, in step S346, it is determined whether the previous time is the phase correction C or the phase correction E, and if it is determined that the previous time is the phase correction C or the phase correction E,
After the correction switching request is made in step S347, the process proceeds to step S306. On the other hand, when it is determined in step S346 that the previous time is not the phase correction C or the phase correction E, step S346
Proceed to 306. If it is determined in step S305 that the correction angle is less than 60 deg, the process proceeds to step S351, the phase correction C is performed, and the process proceeds to step S352. Then, in step S352, it is determined whether or not the previous time is the phase correction D or the phase correction E, and if it is determined that the previous time is the phase correction D or the phase correction E, the process proceeds to step S353, and after the correction switching request is made, It proceeds to step S306. On the other hand, if the previous time is not the phase correction D or the phase correction E in step S352, the process proceeds to step S306.

Next, in step S306, the timer value TISO is set.
U is calculated for each of the phase corrections C, D and E. That is, in the phase correction C, the timer value according to the phase correction angle is set in the timer value TISOU, and in the phase correction D, the timer value TISOU is set.
A timer value corresponding to the phase angle obtained by subtracting 60 degrees from the phase correction angle is set in U, and in the phase correction E, the timer value TISO is set.
A timer value corresponding to the phase angle obtained by subtracting 120 deg from the phase correction angle is set in U. Then, the process proceeds to step S307, and the inverter mode is advanced by one step.

Next, the process proceeds to step S308 shown in FIG. 8,
It is determined whether or not there is a correction switching request, and if there is a correction switching request, the process proceeds to step S361, and correction switching is the phase correction C
It is determined whether or not to switch from (correction C in FIG. 8 ) to phase correction D (correction D in FIG. 8 ) or from phase correction D to phase correction E (correction E in FIG. 8 ), If it is determined that the correction switching is switched from the phase correction C to the phase correction D or from the phase correction D to the phase correction E, the process proceeds to step S362.
The correction switching request is canceled, the inverter mode is returned by one step in step S362-1, and the process proceeds to step S309.

On the other hand, when the correction switching does not switch from the phase correction C to the phase correction D or from the phase correction D to the phase correction E in step S361, that is, from the phase correction D to the phase correction C.
Alternatively, when switching from the phase correction E to the phase correction D, the process proceeds to step S363 and the voltage pattern is output. And
After proceeding to step S364 and setting the timer value TISOU calculated in step S306 to the timer T1, step S365
Start timer T1 with. Next, the process proceeds to step S366, the correction switching request is canceled, and the process proceeds to step S309.

If it is determined in step S308 that there is no correction switching request, the process proceeds to step S368 and step S306.
Set the timer value TISOU calculated in step 1 to timer T1,
In step S369, the timer T1 is started, and then step S
Continue to 309.

Next, in step S309, the cycle measuring timer T2
Is stopped, the timer value of the cycle measuring timer T2 is read, and the process proceeds to step S310. Next, in step S310, the period measurement timer T2 is set and started, and the next period measurement is started. Then, in step S311, the cycle calculator 4
1 performs the cycle calculation from the value of the cycle measurement timer T2,
The rotation speed of the motor is calculated by the speed calculation unit 44 from the calculation result. Next, in step S312, the speed control unit 45
Performs speed control based on the speed command signal from the outside,
Output voltage command signal.

Then, as shown in FIG. 9 , the interrupt processing 21
When the counting of the timer T1 started in 1 is finished and the interrupt signal IRQ is output from the timer T1, the interrupt process 22 starts, the voltage pattern is output in step S370, and the interrupt process 22 ends.

As described above, during normal operation, the operation mode instructing section 102 causes the switch SW to turn on the level detection signal 1.
The level determination unit 101 switches the integrated signal to the first
The phase correction angle is adjusted so that it becomes a predetermined value of. First above
The motor is operated at the maximum efficiency by setting the predetermined value of the above to the level of the integrated signal when the brushless DC motor 11 reaches the maximum efficiency. On the other hand, during defrost operation,
The operation mode command unit 102 switches the switch SW to the level detection signal 2, and the level determination unit 52 adjusts the phase correction angle so that the integrated signal becomes the second predetermined value. By setting the second predetermined value to a level higher than the level of the integrated signal when the maximum efficiency is achieved, the motor efficiency is lowered as compared with the normal operation, and the low efficiency operation is performed.
At this time, the motor current of the brushless DC motor 11 increases, the armature coils 1a, 1b, 1c generate heat due to copper loss, and the temperature of the refrigerant discharged from the compressor rises.

Therefore, during the defrosting operation, the brushless DC motor 11 is operated with low efficiency to supplement the heat source for the defrosting, so that the defrosting time can be shortened. In addition, not only defrost operation,
By operating the brushless DC motor at low efficiency at the time of starting the heating operation, it is possible to raise the temperature of the refrigerant discharged from the compressor and quickly raise the blowout temperature of the indoor unit at the time of starting the heating.

Further, the phase correction means consisting of the phase correction timer T1, the cycle measuring timer T2, the cycle calculating section 41 and the timer value calculating section 42 and the rotary position detector 3 switch the position signal from the rotary position detector 3. It is possible to correct the phase from the time of switching to the time when the pattern of the voltage applied to the armature coils 1a, 1b, 1c is switched, and operate the motor of the compressor with high efficiency or low efficiency.

Further, by advancing the phase of the output of the inverter 20 with respect to the induced voltage induced in each of the armature coils 1a, 1b, 1c of the brushless DC motor 11, the motor is operated with low efficiency. As in the case of inserting a pattern that causes reverse torque of the motor into the motor to reduce the motor efficiency, torque ripple etc. does not occur in the motor and vibration does not occur, and it is possible to rotate the motor smoothly. it can.

[0046] In the embodiments above Symbol embodiment, by controlling the rotation speed by adjusting the output voltage of the inverter 20, adjusts the phase of the voltage pattern of the output of the inverter 20, the optimal efficiency of operating the motor at the maximum efficiency Although the control is performed, the rotation speed is controlled by adjusting the phase of the voltage pattern of the output of the inverter, and the optimum efficiency control for operating the motor at maximum efficiency may be performed by adjusting the output voltage of the inverter. .

[0047] In addition, in the form of the above Symbol implementation, brushless D
Although the C motor is used, the motor is not limited to the DC motor, and it goes without saying that the present invention may be applied to an AC motor such as a reluctance motor or an induction machine.

[0048] In the embodiments above Symbol embodiment, so that the level of the integration signal becomes equal to or higher than the predetermined value has been adjusted phase correction angle, the level of the voltage difference signal may be equal to or greater than a predetermined value.

[0049] Further, in the embodiment above Symbol embodiment, the phase correction timer T1 as phase correcting means, the cycle measuring timer T2, but using periodic calculation unit 41 and the timer value calculating section 42, not a limited to the phase correction means Of course.

[0050] Further, in the embodiment above Symbol embodiment, the phase correction angle command is changed every 1 deg, phase correction angle command is not limited to each 1 deg, may be changed every appropriate value.

[0051] In addition, in the form of the above Symbol implementation, Maiko down 1 4
However, a logic circuit or the like may be used instead of the microcomputer .

Further, in the above embodiment , the rotational position detector 3 is used as the rotational position detecting means, but the circuit configuration of the rotational position detecting means is not limited to this, and other circuit configurations may of course be used. .

That is, as shown in FIG. 10 , the neutral point voltage V _M of the resistor circuit 2 is connected to the inverting input terminal, and the resistor R ₂₁ is connected between the non-inverting input terminal and the ground GND. , A resistor R ₂₂ is provided between the output terminal and the inverting input terminal.
An amplifier IC21 where the capacitor C ₂₁ is connected in parallel with,
Inverting input terminal to the output terminal of the amplifier IC21 is connected, the resistor R ₂₃ between the non-inverting input terminal and the ground GND
There is connected, or may be that having an amplifier IC22 are connected a resistor R ₂₄ between the output terminal and the non-inverting input terminal.

As shown in FIG. 11 , the neutral point voltage V _M of the resistor circuit 2 is connected to the inverting input terminal, and the resistor R ₃₁ is connected between the non-inverting input terminal and the ground GND. , the output terminal and the amplifier IC31 of resistance R ₃₂ is connected between the inverting input terminal, is connected to the inverting input terminal via the output terminal and the resistor R ₃₃ of the amplifier IC31, and a non-inverting input terminal and the ground GND A resistor R ₃₄ is connected between the amplifier IC 32 and a resistor R ₃₅ and a capacitor C ₃₁ are connected in parallel between the output terminal and the inverting input terminal, and an inverting input terminal is provided at the output terminal of the amplifier IC 32. A resistor R ₃₆ may be connected between the non-inverting input terminal and the ground GND, and an amplifier IC 33 having a resistor R ₃₇ connected between the output terminal and the non-inverting input terminal may be provided.

As shown in FIG. 12 , the armature coils 1a, 1b and 1c are Y-connected, and the stator 1 for rotating a rotor 10 having a plurality of permanent magnets by a rotating magnetic field and the armature coil 1a. , 1b, 1c are connected in parallel, and are composed of a resistor circuit 2 in which resistors 2a, 2b, 2c are Y-connected, and transistors 20a to 20f.
In the one provided with the inverter 20 in which the emitters of e and 20f are connected to the ground GND, the armature coils 1a and 1a
b, the voltage V _N at the neutral point of 1c is connected to the inverting input terminal via a resistor R _41, resistors 2a, 2b, together with the voltage V _M at the neutral point of 2c is connected to the non-inverting input terminal, An amplifier IC in which a resistor R ₄₂ is connected between the non-inverting input terminal and the ground GND and a resistor R ₄₃ is connected between the output terminal and the inverting input terminal.
41, the output terminal of the amplifier IC 41 and the inverting input terminal are connected via a resistor R ₄₄ , and the non-inverting input terminal and the ground G
A resistor R ₄₅ is connected between ND and an amplifier IC _{42 in} which a resistor R ₄₆ and a capacitor C ₄₁ are connected in parallel between an output terminal and an inverting input terminal, and the output terminal of the amplifier IC ₄₂ is inverted. An amplifier IC 43 having an input terminal connected thereto, a resistor R ₄₇ connected between the non-inverting input terminal and the ground GND, and a resistor R ₄₈ connected between the output terminal and the non-inverting input terminal is provided. It may be one.

[0056]

As apparent from the above, according to the present invention, an air conditioner of the first aspect of the present invention, comprises a motor for driving the compressors, and an inverter for switching the pattern of the voltage applied to the armature coil of the motor in the air conditioner, based on a change of the voltage level of the neutral point of the armature coils, the control unit, when operating the motor at high efficiency, electrical
The voltage level at the neutral point of the child coil becomes the level at the time of high efficiency.
The inverter output phase or output voltage.
On the other hand, when operating the motor with low efficiency,
The voltage level at the neutral point of the coil becomes the level at the time of low efficiency
Thus, the phase of the output of the inverter or the output voltage is controlled.

Therefore, according to the air conditioner of the first aspect of the present invention, for example, during the defrost operation, the output of the inverter is controlled based on the change in the voltage level of the neutral point of the armature coil of the motor, and the compressor is controlled. By operating the above motor with low efficiency, the motor current increases and the armature coil of the motor generates heat. Therefore, the heat equivalent of the work of the compressor is increased, and the temperature of the refrigerant discharged from the compressor is increased.
The defrost time can be shortened. Further, torque ripple or the like due to reverse torque does not occur in the motor, and vibration does not occur, and high efficiency operation or low efficiency operation can be performed while smoothly rotating the motor.

The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the operation mode selection means of the control means selectively selects a high efficiency operation mode and a low efficiency operation mode. However, the low-efficiency operation mode is selected during the defrost operation.

Therefore, according to the air conditioner of the second aspect of the present invention, by selecting the low-efficiency operation mode during the defrost operation, the motor current increases and the armature coil heats up, and the heat of the work of the compressor is generated. The equivalent amount increases and the temperature of the discharged refrigerant rises. Therefore, since the heat source for defrosting is supplemented by operating the motor at low efficiency during defrosting operation, the defrosting time can be shortened and the indoor comfort is improved.

The air conditioner according to a third aspect of the present invention is the air conditioner according to the first aspect, wherein the operation mode selection means of the control means selectively selects a high efficiency operation mode and a low efficiency operation mode. Then, the low efficiency operation mode is selected when the heating operation is started.

Therefore, according to the air conditioner of the third aspect of the invention, the motor current increases and the armature coil generates heat by selecting the low-efficiency operation when the heating operation is started up. The heat equivalent of work increases and the temperature of the discharged refrigerant rises. Therefore, when the heating operation is started up, even if the compressor is at a low temperature due to a long stop time, by operating the motor with low efficiency, the blowout temperature of the indoor unit at the time of heating start-up can be quickly raised. It is possible to improve indoor comfort.

An air conditioner according to a fourth aspect of the present invention is the air conditioner according to any one of the first to third aspects, wherein the rotational position detecting means of the control means includes a rotor and a stator of the motor. The relative rotation position between the two is detected and a position signal is output, and the phase correction means corrects the phase from the switching point of the position signal to the switching of the voltage pattern.

Therefore, according to the air conditioner of the fourth aspect of the present invention, the phase correction means corrects the phase from the time when the position signal is switched to the time when the voltage pattern is switched so that the efficiency becomes high. On the other hand, the phase from the switching point of the position signal to the switching of the voltage pattern is advanced and corrected to the phase side higher than that at the high efficiency so that the efficiency becomes low. Therefore, it is possible to operate the motor with high efficiency or low efficiency while smoothly rotating the motor of the compressor.

An air conditioner according to a fifth aspect of the present invention is the air conditioner according to any one of the first to third aspects, in which the voltage correcting means of the control means corrects the output voltage of the inverter. .

Therefore, according to the air conditioner of the fifth aspect of the present invention, the output voltage of the inverter is corrected to be low efficiency while the output voltage of the inverter is corrected to be high efficiency by the voltage correction means. Correct the voltage to a voltage lower than that at high efficiency. Therefore, it is possible to operate the motor with high efficiency or low efficiency while smoothly rotating the motor of the compressor.

[Brief description of drawings]

FIG . 1 is a configuration diagram of a brushless DC motor of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a level detector of the brushless DC motor.

FIG. 3 is a block diagram of a microcomputer of the brushless DC motor.

FIG. 4 is a diagram showing signals of respective parts when the level detector is used.

FIG. 5 is a flowchart showing an interrupt process 21 of the microcomputer.

FIG. 6 is a flowchart showing an interrupt process 21 of the microcomputer.

FIG. 7 is a flowchart showing an interrupt process 21 of the microcomputer.

FIG. 8 is a flowchart showing an interrupt process 21 of the microcomputer.

FIG. 9 is a flowchart showing an interrupt process 22 of the above microcomputer.

FIG. 10 is a circuit diagram of a rotation position detector of another example.

FIG. 11 is a circuit diagram of another example of a rotational position detector.

FIG. 12 is a circuit diagram of a rotation position detector of another example.

FIG. 13 is a Mollier diagram during heating operation.

[14] Figure 1 4 is a Mollier diagram during the defrost operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stator, 1a, 1b, 1c ... Armature coil, 2 ... Resistance circuit, 3 ... Rotation position detector , 14 ... Microcomputer , 5 ... Base drive circuit , 9 ... AC power supply, 10 ... Rotor, 12 ... Diode bridge 20 ... Inverter, 20a to 20f ... Transistor, 41 ... Period computing unit, 42 ... Timer value computing unit, 4
3 ... Inverter mode selection unit, 44 ... Speed calculation unit, 45
... speed control unit, 46 ... PWM unit , 101 ... level determination unit, 102 ... operation mode command unit T1 ... phase correction timer,
T2: Period measurement timer.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Tanaka, 1000 Otani, Okamoto-cho, Kusatsu-shi, Shiga 2 Daikin Industry Co., Ltd. Shiga Works (72) Inventor Kazunobu Oyama 1000 Otani, Okamoto-cho, Kusatsu-shi, Shiga No. 2 Daikin Industry Co., Ltd. Shiga Works (56) Reference JP-A-6-185835 (JP, A) JP-A-6-265244 (JP, A) JP-A-6-235547 (JP, A) JP-A-6-235547 (JP, A) 7-31186 (JP, A) JP-A-5-15190 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 1/00-47/02 H02P 6/02

Claims (5)

(57) [Claims] 1. An air conditioner comprising a motor (11) for driving a compressor and an inverter (20) for switching a pattern of voltage applied to armature coils (1a, 1b, 1c) of the motor (11). In the machine, the voltage level of the neutral point of the armature coil (1a, 1b, 1c)
The motor (11) is operated with high efficiency based on the change of
The armature coil (1a, 1b, 1c) of the neutral point
In order to keep the voltage level at the high efficiency level,
One for controlling the phase of the output of the burner (20) or the output voltage
On the other hand, when operating the motor (11) with low efficiency,
The voltage level of the neutral point of the armature coil (1a, 1b, 1c) is low.
An air conditioner comprising a control means (14) for controlling the phase or output voltage of the output of the inverter (20) so as to attain a level at the time of efficiency . 2. The air conditioner according to claim 1 ,
The control means (14 ) selectively selects the high-efficiency operation mode and the low-efficiency operation mode and also selects the low-efficiency operation mode during defrost operation.
An air conditioner comprising (102). 3. The air conditioner according to claim 1 ,
The control means (14 ) includes an operation mode selection means ( 102) for selectively selecting the high-efficiency operation mode and the low-efficiency operation mode and selecting the low-efficiency operation mode at the start of heating operation. An air conditioner characterized by being equipped. 4. The air conditioner according to any one of claims 1 to 3 , wherein the control means (14 ) includes a rotor (10) of the motor (11) and a stator (2). A rotational position detecting means (3) for detecting a relative rotational position between them and outputting a position signal, and a phase correcting means (3) for correcting the phase from the time when the position signal is switched to the time when the voltage pattern is switched ( T1, T2, 41, 42). 5. A one of the air conditioner according to claim 1 to 3, wherein the control means (1 4), in order to control the output of the inverter (20), the inverter
An air conditioner comprising voltage correction means for correcting the output voltage of (20).