JP2001119981A - Compressor drive-control device and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress vibration and noise by fully maximizing torque pulsation correction within the allowed value of an inverter input current and to surely prevent burning or the like of equipment and circuit components. SOLUTION: A compressor drive-controlling device 10 is provided with a brushless DC motor 20 for rotating a compressor 26, drive means 18, 42, and 32 for driving the motor 20 in PWM(pulse width modulation) system, and means 28, 30, and 32 for correcting conduction duty factor during a rotation to the brushless DC motor when the operating frequency of the compressor 26 is equal to or less than a fixed value, The device is provided with a means 32 for reducing the amount of correction of the torque pulsation correction, as the operating frequency of the compressor 26 increases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor driving device which suppresses pulsation of torque generated during operation of a compressor, and an air conditioner equipped with this device.

[0002]

2. Description of the Related Art Conventionally, in air conditioners, for example, Japanese Patent Publication No. Hei 4-36000, Japanese Patent Publication No. Hei 6-48916, Japanese Patent Laid-Open No. 10-174488, and Japanese Patent Laid-Open No. 11-46493.
As seen in the above publication, a compressor drive control device that drives a compressor by rotating a brushless DC motor (a non-commutator DC motor) is often used.

As a compressor, there is a compressor having a rotary compression mechanism of a one-cylinder structure or a two-cylinder structure, and a rotary shaft of a brushless DC motor is directly connected to the compression mechanism of the compressor. This motor is
Since the motor is driven to rotate by a PWM (pulse width modulation) method by an inverter forming a motor driving device, the compressor also rotates integrally with the rotation of the motor.

[0004] This compressor, particularly a compressor having a one-cylinder structure, has large torque pulsation accompanying its operation. Since this pulsation causes vibration and noise from the outdoor unit, the torque pulsation correction for suppressing the pulsation of the torque is usually performed by varying the duty ratio (duty) of the voltage in a specific phase section during one rotation of the motor. .

In correcting the torque pulsation, a determination is made of the torque pulsation phase angle. The compressor is connected to a four-way valve as an electromagnetic control valve for switching the refrigerant flow path. When the motor is started, the energization of the four-way valve is switched, and the torque pulsation phase angle is determined immediately after the motor is started.

[0006]

However, in the above-described conventional torque pulsation correction, when this correction is performed, the motor winding current pulsates greatly, and the input current of the motor drive device, that is, the inverter input current also pulsates. And the peak value tends to increase. Therefore, such a peak value may exceed the allowable range of the inverter depending on the indoor / outdoor temperature, the set temperature, and other environmental conditions. If such a deviation occurs, there arises a problem that the device and the circuit component are burned out and the life resistance is reduced.

Further, according to the above-described timing relationship between the start of the motor, the energization of the four-way valve, and the determination of the torque pulsation phase angle, the four-way valve may operate during the determination. In such a situation, the torque fluctuation during one rotation is disturbed,
The speed difference between the rotation phase having a large torque and the rotation phase having a small torque cannot be accurately obtained. That is, there is a problem in that the torque phase angle is not accurately determined, resulting in an erroneous determination.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has the effect of reducing vibration and noise by maximizing torque pulsation correction within an allowable value of an input current of an inverter (motor driving device). It is a first object of the present invention to suppress power consumption and to reliably prevent burnout of devices and circuit components.

It is a second object of the present invention to prevent erroneous determination of the torque pulsation phase angle, obtain a more accurate determination result of the torque pulsation phase angle, and perform accurate torque pulsation correction accordingly. .

Further, even if the torque pulsation phase angle is erroneously determined for some reason, as a next best measure, it is ensured that the erroneous determination is made from the torque pulsation state during the torque pulsation correction. It is a third object of the present invention to control the operation so that the torque pulsation correction is interrupted or the normal torque pulsation correction can be performed, and to reliably eliminate the transition to a control state in which vibration and noise are accelerated.

[0011]

According to the first aspect of the present invention, there is provided a brushless DC motor for rotating a compressor, and a brushless DC motor for rotating the compressor.
Driving means for driving the C motor by a PWM (pulse width modulation) method; and torque for correcting the energization duty during one rotation to the brushless DC motor for each predetermined electrical angle when the operating frequency of the compressor is equal to or lower than a predetermined value. A compressor drive control device including a pulsation correction unit, wherein a correction amount adjustment unit that adjusts a correction amount of the torque pulsation correction performed by the torque pulsation correction unit in accordance with the operating frequency.

For this reason, the vibration and noise in the low operating frequency range due to the operation of the compressor are suppressed by the torque pulsation correcting means. At the same time, unlike the case where a constant pulsation correction amount is maintained even when the operating frequency of the compressor changes, the correction amount is adjusted to the correction amount according to the operating frequency by the correction amount adjusting means. Circuit elements can be reliably protected from overcurrent. A part of this specific mode can be developed and provided as follows.

Preferably, the correction amount adjusting means is means for reducing the correction amount as the operating frequency increases. For example, claim 3
It is preferable that the correction amount adjusting means is means for reducing the correction amount at a constant rate as the operating frequency increases.

According to a fourth aspect of the present invention, while the driving means includes an inverter, the correction amount adjusting means detects a peak value of a ripple of a current flowing through the inverter; Adjusting means for adjusting the correction amount according to the peak value of the current ripple detected by the means.

On the other hand, in order to achieve the first object, according to a fifth aspect of the present invention, there is provided an air conditioner including a compressor drive control device similar to the first aspect. In the air conditioner, the compressor drive control device may include a current value detection unit that detects a value of an alternating current supplied to the air conditioner, and a correction amount of a torque pulsation correction performed by the torque pulsation correction unit. Correction amount adjusting means for adjusting according to the AC current value detected by the current value detecting means.

[0016] In particular, according to the air conditioner of the present invention, while the driving means includes an inverter,
A ripple peak value detecting means for detecting a peak value of a ripple of a current flowing through the inverter; and reducing the torque correction amount when the peak value detected by the ripple peak value detecting means reaches a predetermined upper limit value. Operation control means for judging whether or not the peak value has decreased by a certain value from the predetermined value, and driving the brushless motor so that the operation frequency increases when it is determined that the peak value has decreased; And

According to the air conditioner of the present invention, the driving means includes an inverter, and the ripple peak value detecting means for detecting a peak value of a ripple of a current flowing through the inverter; First determining means for determining whether the ripple peak value detected by the ripple peak value detecting means has decreased when the torque pulsation is corrected by reducing the correction amount by the torque pulsation correcting means, Interruption command means for interrupting the torque pulsation correction by the torque pulsation correction means when it is determined by the first determination means that the current ripple peak value does not decrease; and after the correction interruption, the ripple peak value detection means A second determining means for determining whether or not the current ripple peak value detected by
Operating control means for driving the brushless DC motor so that the operating frequency is increased to a value exceeding the predetermined value when the current ripple peak value is determined to have decreased by the determining means.

Further, according to the air conditioner of the present invention, when the second judging means judges that the current ripple peak value does not decrease, the brushless motor is operated to interrupt the operation of the compressor. An interrupt command unit for interrupting the rotation of the DC motor is provided. According to a ninth aspect of the present invention, the operation control unit includes a prohibition unit that prohibits operation of the compressor at a predetermined value or less until the next operation start of the compressor.

With this configuration, for example, when the input current of the driving means (for example, an inverter), the input current of the air conditioner (air conditioner set current), and the motor rotation speed (operating frequency) increase, the torque pulsation correction is performed. The correction amount is reduced. Accordingly, the torque pulsation correction can be maximized within the allowable value of the input current of the driving means, thereby effectively suppressing vibration and noise, and reliably preventing burnout of devices and circuit components. In addition, the life of the device can be extended.

On the other hand, in order to achieve the second object of the present invention, according to the tenth aspect of the present invention, there is provided a brushless DC motor directly connected to a compressor connected to a four-way valve and driving the compressor at a variable speed. An air conditioner equipped with a compressor drive control device including: a drive unit that drives the brushless DC motor in a PWM (pulse width modulation) system; and a phase detection unit that detects a pulsating phase of the load torque of the compressor. The compressor drive control device includes an energization prohibition unit that prohibits a change in the energization state of the four-way valve during a period in which the phase detection unit detects the pulsating phase of the load torque.

For example, according to the eleventh aspect of the present invention, the compressor drive control device energizes the four-way valve and stabilizes the position of the four-way valve. The brushless DC motor is provided with start-up means for starting, and after this start-up, an operation command means for operating the phase detection means.

Thus, the switching of energization to the four-way valve and the determination of the torque pulsation phase angle can be prevented from being performed at the same time. Therefore, a more reliable torque pulsation phase angle determination result can be provided, and accurate torque pulsation correction can be performed by reflecting this determination result.

Further, according to the twelfth aspect of the present invention, in order to achieve the third object of the present invention, even if torque pulsation correction is performed in a compressor drive control device having the same configuration as described above, torque pulsation is corrected. If does not decrease, the operation control means for interrupting the torque pulsation correction and controlling the drive of the brushless DC motor so that the compressor is prohibited from operating at the operating frequency equal to or lower than the predetermined value until the next operation. It is characterized by having.

As a result, even if the torque pulsation phase angle is erroneously determined for some reason, it is reliably grasped as a next best measure from the state of the torque pulsation during the torque pulsation correction. You. For this reason, the operation is controlled so that the torque pulsation correction is interrupted or the normal torque pulsation correction can be performed, and the transition to a control state in which vibration and noise are accelerated is reliably eliminated.

As an example, in the invention of claim 13, the compressor is a rotary type compressor having a one-cylinder structure. As a result, even in a compressor having a large torque pulsation, the pulsation is accurately corrected, the generation of vibration and noise is suppressed, and the circuit element can be protected from overcurrent.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. <First Embodiment> An air conditioner according to a first embodiment will be described with reference to FIGS. explain. This air conditioner is implemented by applying the compressor drive control device according to the present invention.

FIG. 1 is a block diagram showing a partial configuration of a compressor drive control device 10 of an air conditioner.

The compressor drive control device 10 includes a rectifier circuit 14 to which AC power is supplied from an AC power supply 12. The smoothing capacitor 1 is connected to the output terminal of the rectifier circuit 14.
6 are connected in parallel, and an inverter 18 as driving means is connected. The inverter 18 includes a semiconductor switch group including six transistors and six diodes connected in anti-parallel to the respective transistors. The base voltage of each transistor is controlled by a PWM driver (to be described later) in a PWM (pulse width modulation) system.

The three output terminals of the inverter 18 are connected to a brushless DC motor 20. This brushless D
The C motor 20 has three armature windings 22 connected in three phases.
And a magnet rotor 24. While three armature windings 22 are respectively connected to the output terminal of the inverter 13 described above,
The magnet rotor 4 is mechanically directly connected to the shaft of the compressor 26.

In this embodiment, the compressor 26 includes:
A one-cylinder rotary type is employed.

Each of the three armature windings 22 of the brushless DC motor 20 is also electrically connected to a rotor position detector 28, and the voltage induced in each armature winding 22 is detected by this detector. 28. Rotor position detector 28
Converts the voltage signal into a rotor position pulse signal and outputs it to the counter 30 at the subsequent stage. The counter 30 counts, for example, an edge of the rotor position pulse signal, and outputs a count signal corresponding to the count value to the controller 32.

The controller 32 includes an interface circuit 34 for transferring signals and matching the signal levels, a CPU 36 for controlling the compressor drive control function, a ROM 38 for storing programs and initial values, etc. in advance.
And a microcomputer provided with a RAM 40 capable of writing and reading data.

The controller 32 includes the CPU 3
A driver 42 that changes the energization state of the inverter 18 based on the drive signal and the PWM signal supplied from the controller 6
Is connected.

Further, the compressor drive control device 1
0 is provided with two current detectors 44 and 46 for non-contact current detection, one of which is arranged on the input line of the inverter 18 and the other is arranged on the output line of the AC power supply 12. I have. The current detection signals from the two current detectors 44 and 46 are supplied to the controller 32 via A / D converters 48 and 50, respectively.

Further, the controller 32 is also connected via another driver 52 to the coil of the four-way valve 52 forming the structure of the electromagnetic control valve. Thereby, the four-way valve 52 can be energized to change its connection path to one of the cooling cycle and the heating cycle. This four-way valve 52
Is inserted into a circulation system constituting a refrigeration cycle of the refrigerant, and is also connected to the compressor 26 described above.

The programs stored in the ROM 38 of the controller 32 include routines described later with reference to FIGS. Through these routines,
Functions such as speed control of the brushless DC motor 20 by the PWM method (that is, operation control of the compressor 26), correction of torque pulsation of the compressor 26, and adjustment of the correction amount of torque pulsation correction, which is a feature of the present invention, are implemented by software. It is realized by hardware.

Therefore, the brushless DC motor 20 and the compressor 2 are included in the constituent requirements described in the claims.
6 and the components other than the four-way valve 54 are the CPU 36
The function is realized by the partial or full involvement of the microcomputer centered on, and is shown in the flowchart (the same applies to the second and third embodiments described later). The ROM 38 also serves as a recording medium for executing the present invention.

Returning to the first embodiment, FIGS. 2 and 3 both show the outline of the compressor drive control executed by the CPU 36. Among them, the main processing of FIG. 2 is started in response to power-on, and outlines the main processing repeatedly executed until power-off. The other processing of FIG.
The outline of a timer interrupt process executed at regular small time intervals Δt during execution of the main process of FIG.

The outline of the main processing of FIG. 2 will be described. CP
After the activation, the U36 performs a predetermined initialization process (step S1). Next, the CPU 36 reads the count signal output from the counter 30, and based on the count signal, the current motor rotation speed, that is, the compressor 2
6 is detected (step S2).

Next, the CPU 36 reads a speed command signal commanded from the outside, calculates the difference (speed difference) between the operating frequency corresponding to this signal and the current operating frequency n, and responds to this difference value. A rotation speed command value _VP is calculated (step S3).

Thereafter, the CPU 36 determines whether or not n ≦ N with respect to the current operating frequency n and the preset torque pulsation correction upper limit frequency N (step S4). Generally, when the compressor 26 is operated at a low frequency, vibration and noise increase due to the pulsation of the torque.
A torque pulsation correction upper limit frequency N is set to suppress the vibration and noise suppression range. That is, the torque pulsation correction upper limit frequency N is the maximum frequency (maximum rotational speed) at which the torque pulsation correction is performed, and specifies that the torque pulsation correction is performed in a frequency range lower than this value.

If the determination in step S4 is NO, that is, n
If> N, the process of the next step S5 is skipped, while this determination is YES, that is, n
When ≤N is satisfied, it is recognized that the frequency is within the predetermined low frequency range, and the process proceeds to step S5. In this step, the CPU 36 determines the current torque pulsation correction amount S _C that has been updated substantially in real time by the processing of FIG.
From a predetermined storage area in the RAM 40.

Next, the rotational speed command value _VP and the torque pulsation correction amount S calculated and read out in the above two steps.
_A total rotation speed command value V based on _C is calculated (step S6). Then, the CPU 36 outputs a drive signal and a PWM signal according to the total command value V to the driver 42, thereby instructing the driver 42 to control the rotation speed of the brushless DC motor 20 (step S7). As a result, the driver 42 performs PWM control on the duty ratio of energization in the inverter 18 in accordance with the command value V, so that the rotation speed of the motor 20, that is, the operating frequency of the compressor 26 is controlled to a value corresponding to the command value V.

When the command of the rotation speed control is completed, CP
U36 performs stop control (step S8). That is,
It is determined whether or not a predetermined stop condition is satisfied. If such a condition is satisfied, a command required to stop the rotation of the brushless DC motor 20 is issued to the driver 42. If the stop condition is not satisfied, the process returns to step S2. The above-described processing is repeated.

On the other hand, the timer interrupt processing of FIG. 3 is executed at regular time intervals Δt while the main processing of FIG. 2 is being executed. When the interrupt process is started, the CPU 36 detects the current rotation speed of the brushless motor 20 (that is, the current operating frequency n of the compressor) from the count signal of the counter 30 (step S11). Next, it is determined whether or not n ≦ N (N: torque pulsation correction upper limit frequency) for the operating frequency n (step S12). If NO in this determination, that is, if n> N, the process returns to the main process without doing anything.

[0046] However, YES determination, namely satisfied the condition of n ≦ N is, when the operation frequency n is in the lower region, then adjust the torque pulsation correction amount S _C depending on the operating frequency n, and stores Perform processing (step S1)
3). Update of the correction amount _{S C} is, for example, ROM 3
8 is executed with reference to a table stored in advance in a predetermined storage area.

FIGS. 4 and 5 show examples of this table.
Both figures together, the horizontal axis represents the operating frequency n, the vertical axis takes the torque pulsation correction amount S _C, data corresponding to the graph is previously stored as a table. According to the graph of the torque correction amount S _C of FIG. 4, when the operation frequency n reaches a predetermined value rising to a maximum correction amount, then it decreases linearly to the torque ripple correction upper limit frequency N. In contrast, the graph of the torque correction amount S _C of Figure 5, the operation frequency n reaches a predetermined value rising to a maximum correction amount, then stepwise decreased to the torque ripple correction upper limit frequency N.

Which correction amount curve of FIG. 4 or FIG. 5 is adopted is arbitrary. Moreover, it is not necessary to take the configuration determined by necessarily table references updating of the correction amount S _C, for example, each time, may be obtained by solving an equation of the operating frequency n and function.

[0049] Therefore, even by the one of the correction amount curve of FIG. 4 or FIG. 5, becomes smaller correction amount S _C as the current operation frequency n becomes higher point by point, it is updated and set. Naturally, when the operation frequency n is low, the correction amount S _C is updated set to a higher value.

[0050] When updating of the correction amount S _C end, then processing returns to the main process. Accordingly, the correction amount S _C that are called in the main processing described above is always a value reflecting the height of the operation frequency n at that time is set in near real time.

For this reason, in the rotation speed control at the time of n ≦ N executed through step S7 in FIG. 2, the PWM duty based on the difference between the speed command signal supplied from the outside and the current operation frequency is used. The torque pulsation correction amount S _C whose ratio is adjusted as described above at a specific phase during one rotation of the rotor.
Only a rate equivalent is up to, or is down by a rate equivalent at a specific phase adjustment torque pulsation correction amount S _C as described above.

In general, when the motor rotation speed (compressor operation frequency) increases, the input current of the inverter increases. Therefore, if the torque pulsation is always corrected with the same correction amount as in the related art, the increase in the operation frequency is conventionally required. As the operating frequency increases, a current that exceeds the allowable value of the inverter easily flows.

However, in this embodiment, the control method of always increasing or decreasing the duty ratio at the same constant rate even when the operating frequency is changed as in the prior art is not employed, and the operating frequency is increased as described above. As a result, the torque pulsation correction amount is reduced continuously (see FIG. 4) or stepwise (see FIG. 5).

For this reason, even if the load torque increases due to environmental changes such as the ambient temperature at which the compressor 26 is operating and the current pulsation of the winding of the motor 20 increases, the input current of the inverter 18 increases. A situation in which the allowable current value is instantaneously exceeded can be almost certainly prevented. Therefore, it is possible to almost surely prevent the circuit elements of the inverter 18 from being burned or damaged due to the instantaneous current, and to thereby prolong the life of the inverter itself.

Although the vibration and noise of the compressor 26 appear more remarkably as the operating frequency is lower, in the present embodiment, although the operating frequency is in the low operating frequency range where n.ltoreq.N, the correction is focused on the higher operating frequency in that range. Since the amount is reduced, the effect of the torque pulsation correction as a whole is hardly affected. Therefore, in parallel with the above-described suppression of the inverter current, the same accurate torque pulsation correction as that of the related art can be effectively exerted, and the vibration and noise caused by the compressor can be reliably suppressed.

<Second Embodiment> An air conditioner according to a second embodiment will be described with reference to FIGS. The air conditioner according to this embodiment includes the compressor drive control device 10 having the configuration shown in FIG. 1 described above, and the hardware configuration is the same as that of the first embodiment.

According to the second embodiment, the CPU 36 of the controller 32 performs the above-described processing shown in FIGS. 2 and 3 as its main processing. Operation control
It is additionally executed by the timer interrupt processing shown in FIG. That is, in the second embodiment, in addition to the function exhibited in the first embodiment, a function by the processing shown in FIG. 6 is obtained.

The timer interrupt process shown in FIG. 6 is executed at regular time intervals Δt. When the process of FIG. 6 is started, the CPU 36 reads the current detection signal from the current detector 44 and
Input current i of the inverter 18 are detected, the peak value _{i p} is calculated (step S20, S21).

[0059] Then, with respect to the threshold _{i th} that corresponds to the allowable current value of the inverter 18 is set in advance, the peak value _{i p} is determined whether or not _{i p} ≧ _{i th} (step S22). In this step, the CPU 36
O, that is, when it is determined that the _i p _{<i th} is
The processing is returned to the main processing as it is.

[0060] However, YES, i.e. _{when i p} ≧ _{i th} is recognized as established, performs processing of reducing the torque pulsation correction amount _{S C} depending on the amount of increase in the inverter input current i (step S23). This process is performed by referring to a storage table in the ROM 38 which is set in advance as shown in FIG. 7, for example. According characteristics of the torque pulsation correction amount S _C of the figure, while the correction amount S _C with increasing as in the first embodiment the operating frequency n decreases, the larger the inverter input current, the correction amount S The value of the whole _C is reduced. Therefore, even with the same operation frequency n, the inverter input current i is increased, is updated set corresponding value by the torque ripple correction amount S _C which was reduced to its increase.

[0061] Incidentally, the data referred to in this step S23, among the characteristics shown in FIG. 7, only the relationship of the inverter input current i and the torque ripple correction amount S _C (operation frequency n and the torque ripple correction amount S _C The relationship is already referred to in the above-described processing of FIG. 3).

[0062] After the update setting, CPU 36 again detects the inverter input current i, computes the peak value i _p, further peak value i _p is determined whether decreased by more than a predetermined value (step S24 To S26). This judgment is YE
S When the (peak value i _p is decreased by more than a predetermined value) becomes, in its time, smaller correction amount than the torque ripple correction amount in the operating frequency before performing the process of reducing the correction amount in accordance with the inverter input current The CPU 36 issues a command to increase the operating frequency by an amount corresponding to the decrease in the correction amount (that is, increase the rotational speed of the motor by an amount corresponding to the decrease in the correction amount). . Thereby, as shown in FIG. 8, for example, the operating frequency is increased, and the vibration and noise of the compressor 26 are suppressed.

In general, considering that such a situation is not instantaneously improved, CPU 36 then
Until the next compressor startup, operation at a value equal to or lower than the lowest frequency at which operation can be performed with the torque pulsation correction amount at that time is prohibited (step S28: see FIG. 8).
As a result, "the operating frequency decreases, the current pulsation increases,
It is possible to avoid a hunting phenomenon of "decrease in torque pulsation correction amount, increase in operating frequency, and decrease in pulsation current". After step S28, the process returns to the main process.

On the other hand, if NO in step S26 described above, that is, if it is determined that the peak value of the inverter input current does not decrease even if the torque pulsation correction amount is reduced in accordance with the increase in the inverter input current, the CPU 36 sets the torque A pulsation correction interruption command is issued (step S29). Then
Detecting the inverter input current i, it computes the peak value i _p, further peak value i _p is determined whether decreased by more than a predetermined value (step S30 to S32). This judgment is Y
When the ES (peak value i _p is lowered than a predetermined value), in order to suppress the vibration and noise from the compressor is increased due to the interruption of the torque pulsation correction, as illustrated in FIG. 9, the operating frequency Is the torque pulsation control upper limit frequency N
(Step S33). Thereafter, the process returns to the main processing.

On the other hand, if NO in step S32, that is, if the inverter input current does not decrease as expected even if the torque pulsation correction is interrupted, the CPU 36 issues a command to interrupt the operation of the compressor itself (step S3).
4). Thereafter, the process returns to the main processing.

The increase in the operating frequency in steps S27 and S33 described above is dealt with by updating the command value V used in the processing of FIG.
9. The operation control command in S34 is dealt with by updating a parameter reflected in the rotation speed control in step S7 in FIG.

As described above, according to the present embodiment, when the load of the brushless DC motor 20 is large, the torque pulsation correction in which the correction amount changes according to the operating frequency n according to the first embodiment is performed. However, it is still possible to detect a situation where the input current of the inverter 18 is likely to exceed its allowable value beforehand and prevent it.
That is, when the inverter input current becomes large, the torque pulsation correction amount is reduced, so that the inverter 18 can be almost surely prevented from being destroyed due to an excessive current.

In addition, if the inverter input current does not drop below the desired value even after the correction amount is reduced in accordance with the increase in the inverter input current for some reason, the interruption of the torque pulsation correction or Since operation control such as operation interruption of the compressor is performed, double and triple protection functions can be provided. As a result, the inverter 18 and its peripheral circuits can be more reliably protected from destruction due to excessive current.

In the second embodiment, FIG.
The target signal when the correction amount is reduced in step S23 is not limited to the inverter input current, and may be, for example, the operating current (set current) of the air conditioner.
This operating current is supplied to the current detector 4 on the AC power supply side shown in FIG.
6 from the current detection signal in the same manner as described above. In accordance with this operating current increases, for example as shown in FIG. 10, by obtaining the torque pulsation correction amount S _C by the table lookup method and operation, you can perform the same control.

<Third Embodiment> An air conditioner according to a third embodiment will be described with reference to FIGS. The air conditioner according to this embodiment includes the compressor drive control device 10 having the configuration shown in FIG. 1 described above, and the hardware configuration is the same as that of the first embodiment.

The compressor drive control device according to the third embodiment controls the start of the brushless DC motor 20, the energization switching of the four-way valve 54, and the timing for determining the torque pulsation phase angle, and the operation related thereto. Features control.

Specifically, the CPU 3 of the controller 32
6, the process partially shown in FIG. 11 is executed as part of the initial setting process related to step S1 in FIG. 1, and the timer interrupt process for each minute time Δt shown in FIG. 12 is executed as operation control. .

According to the processing of FIG. 11, the CPU 36 first switches the energization of the four-way valve 54 to move the four-way valve 54 to a stable flow path position as an example (see (a) of FIG. 13: Step S1a, S1b). Next, the brushless DC motor 20 is started (steps S1c and S1d). Thereafter, a phase angle determination for torque pulsation correction is performed (step S1e). In general, the phase angle determination is performed immediately after the start of the motor, and thus the sequence is also in accordance with this.

As a result, as shown in FIG. 13, the energization of the four-way valve is first switched and, after stabilization, the brushless DC motor 20 is started. After a lapse of a predetermined time, determination of the torque pulsation phase angle is started. Therefore, the four-way valve 26 is actuated during the phase angle determination of the torque pulsation correction as in the related art, and the torque fluctuation during one rotation is disturbed, and the rotation phase between the large torque rotation phase and the small torque rotation phase is changed. A situation in which the speed difference cannot be accurately determined can be prevented.

After the determination of the phase angle for the torque pulsation correction, the energization for switching the position of the four-way valve 54 may be performed (see (b) in FIG. 13).

On the other hand, FIG.
According to the process described in No. 2, the CPU 36 detects the current operating frequency n and determines whether n ≦ N (step S).
41, S42). When the determination is NO (n> N), the process returns to the main process, but when the determination is YES (n ≦ N), the processes of steps S43 to S46 are subsequently performed.

That is, when the torque pulsation correction is started, the time passing through the phase section where the torque pulsation correction is performed is detected, and the average state of the time is obtained (steps S43 to S46).

Next, it is determined whether or not the torque pulsation has been reduced by executing the torque pulsation correction based on the calculated average state (step S47). If the time passing through this phase section is dispersed without being averaged (NO in step S47), the determination of the phase angle of the torque pulsation correction is incorrect, so the parameters are set to interrupt the torque pulsation correction ( Step S48). The operation at the torque pulsation correction upper limit frequency N or lower is prohibited, and the upper limit frequency N
The parameters are controlled so as to operate at a frequency exceeding (step S49). In place of the process of step S49, a process of re-determining the phase angle of the torque pulsation correction may be performed.

As described above, the timing of the phase pulsation correction for the torque pulsation correction can be optimized, and further, the pass / fail judgment of the phase pulsation determination can be checked, and an operation control method in the case of an inadequacy can be provided. In addition to the function and effect, an effect is obtained that torque pulsation correction can be performed stably and more accurately.

In the embodiments shown in FIGS. 4, 7, and 10, the torque pulsation correction amount adjusted with an increase in the operating frequency of the compressor always changes at a constant rate regardless of the change in the operating frequency. Yes (the slope of the correction amount is constant)
However, the relationship between the change in the operating frequency and the torque pulsation correction amount according to the present invention is not necessarily limited to this, and for example, the change as shown in FIGS. May be. The relationship shown in FIG. 7A is obtained by exponentially decreasing the decrease rate of the torque pulsation correction amount as the operating frequency increases, and the relationship shown in FIG. 7B shows the decrease rate of the torque pulsation correction amount. The relationship shown in FIG. 3C shows that the decrease rate of the torque pulsation correction amount is increased in the vicinity of the beginning and end of the increase in the operating frequency. Things. These characteristics can be appropriately selected according to the frequency characteristics of the vibration of the compressor and the like, thereby increasing design flexibility.

Further, in the above-described embodiment, the controller 32 is constituted by a microcomputer as its main element. However, this controller has a digital circuit, a relay, and a switch element so as to have the same functions as those described above. And other sequence circuits.

The above-described embodiments and their modifications are merely examples, and are not intended to limit the scope of the present invention. The scope of the present invention is determined according to the description of the claims, and various modes of the compressor drive control device, the air conditioner, and the recording medium can be implemented without departing from the scope of the present invention.

[0083]

As described above, according to the compressor drive control device and the air conditioner according to the present invention, the torque pulsation correction is maximized within the allowable value of the input current of the drive means such as the inverter. Vibration and noise can be effectively suppressed, and devices and circuit components due to overcurrent can be reliably prevented from being burned, so that a device having a long life and stable performance can be provided. In addition, since an operation control unit for suppressing a current input to the driving unit and the like is provided in addition thereto, a highly reliable device can be provided.

Further, it is possible to prevent erroneous determination of the torque pulsation phase angle, obtain a more accurate determination result of the torque pulsation phase angle, and perform accurate torque pulsation correction accordingly.
Further, even if the torque pulsation phase angle is erroneously determined for some reason, as a next best measure, it is possible to reliably eliminate the transition to a control state in which vibration and noise are accelerated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical schematic configuration of a compressor drive control device of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a schematic flowchart illustrating main processing executed by a CPU according to the first embodiment.

FIG. 3 is a schematic flowchart of a timer interrupt process showing a torque pulsation correction amount update process executed by a CPU according to the first embodiment;

FIG. 4 is a graph showing an example of a relationship between an operating frequency and a torque pulsation correction amount.

FIG. 5 is a graph showing another example of the relationship between the operating frequency and the torque pulsation correction amount.

FIG. 6 is a schematic flowchart of a timer interrupt process mainly showing an update process of a torque pulsation correction amount executed by a CPU in a second embodiment.

FIG. 7 is a graph showing an example of a relationship among an operation frequency, an inverter input current, and a torque pulsation correction amount.

FIG. 8 is a diagram illustrating an example of a temporal change of a torque pulsation correction amount.

FIG. 9 is a diagram showing another example of a temporal change of the torque pulsation correction amount.

FIG. 10 is a graph showing an example of a relationship among an operation frequency, a set operation current, and a torque pulsation correction amount according to a modification.

FIG. 11 is a schematic flowchart of a process executed as a part of an initial setting process by a CPU in a third embodiment.

FIG. 12 is a schematic flowchart of a timer interrupt process showing an operation control executed by a CPU in a third embodiment.

FIG. 13 is a diagram illustrating an example of a time change from a start to a torque pulsation correction.

FIG. 14 is a graph showing another example of the relationship between the operating frequency and the torque pulsation correction amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Compressor drive control device 18 Inverter 20 Brushless DC motor 26 Compressor 28 Rotor position detector 30 Counter 32 Controller 36 CPU 38 ROM 40 RAM 42 PWM driver 44, 46 Current detector 48, 50 A / D converter 52 Driver 54 Four sides valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02P 7/63 302 H02P 6/02 351J (72) Inventor Nariki Ikeda 336 Tatehara, Fuji City, Shizuoka Prefecture Toshiba Carrier (72) Inventor Toshiyuki Morimoto 336 Tatehara, Fuji-shi, Shizuoka Toshiba Carrier Co., Ltd. (72) Inventor Akihiro Oda 336 Tatehara, Fuji-shi, Shizuoka Toshiba Carrier F-term (reference) 3H045 AA09 AA12 AA27 BA38 BA42 CA21 CA29 DA08 EA38 3L060 AA01 CC10 CC19 DD02 DD05 EE04 5H560 AA02 BB12 DA13 DA19 DC03 DC12 EB01 GG04 RR01 SS07 SS10 TT02 TT12 TT13 UA02 XA12 5H576 AA10 BB04 CC05 DD02 DD07 EJ11 GG17 GG04 LL41

Claims (13)

[Claims] 1. A brushless D for rotating a compressor
C motor, driving means for driving the brushless DC motor in a PWM (pulse width modulation) system, and the brushless DC motor when the operating frequency of the compressor is equal to or lower than a predetermined value.
And a torque pulsation correction means for correcting the energization duty during one rotation of the C motor for each predetermined electrical angle. A compressor drive control device comprising a correction amount adjusting means for adjusting according to a frequency. 2. The compressor drive control device according to claim 1, wherein said correction amount adjusting means is means for reducing said correction amount as said operating frequency increases. 3. The compressor drive control device according to claim 2, wherein said correction amount adjusting means is means for reducing said correction amount at a constant rate as said operating frequency increases. 4. The driving unit includes an inverter, the correction amount adjusting unit includes a detecting unit configured to detect a peak value of a ripple of a current flowing through the inverter, and a peak of a current ripple detected by the detecting unit. 2. The compressor drive control device according to claim 1, further comprising adjusting means for adjusting the correction amount according to the value. 5. A brushless D for rotating a compressor
C motor, driving means for driving the brushless DC motor in a PWM (Pull Number Width Modulation) system, and the brushless DC motor when the operating frequency of the compressor is lower than a predetermined value.
An air conditioner equipped with a compressor drive control device including torque pulsation correction means for correcting an energization duty during one rotation of the C motor for each predetermined electrical angle, wherein the compressor drive control device is Current value detecting means for detecting a value of an AC current to be supplied; and correction for adjusting a correction amount of torque pulsation correction performed by the torque pulsation correcting means in accordance with the AC current value detected by the current value detecting means. An air conditioner comprising an amount adjusting means. 6. The driving means includes an inverter, a ripple peak value detecting means for detecting a peak value of a ripple of a current flowing through the inverter, and a peak value detected by the ripple peak value detecting means having an upper limit. When reaching a predetermined value, the torque correction amount is reduced, and it is determined whether or not this peak value is a reduced state in which the peak value is reduced by a certain value from the predetermined value. The air conditioner according to claim 5, further comprising: operation control means for driving the brushless motor so as to increase a frequency. 7. The driving means includes an inverter, a ripple peak value detecting means for detecting a peak value of a ripple of a current flowing through the inverter, and a torque pulsation by reducing the correction amount by the torque pulsation correcting means. First determining means for determining whether or not the ripple peak value detected by the ripple peak value detecting means has decreased when the correction has been made; and the first determining means reduces the current ripple peak value. Interruption command means for interrupting the torque pulsation correction by the torque pulsation correction means when it is determined not to be performed; and, after the correction interruption, whether or not the current ripple peak value detected by the ripple peak value detection means has decreased. And a second determining means for determining that the current ripple peak value has decreased. The brushless D so that the by increasing the operating frequency becomes a value exceeding the predetermined value when the
The air conditioner according to claim 5, further comprising operation control means for driving the C motor. 8. An interruption command means for interrupting the rotation of the brushless DC motor to interrupt the operation of the compressor when the second judgment means judges that the current ripple peak value does not decrease. The air conditioner according to claim 7, wherein: 9. The air conditioner according to claim 7, wherein the operation control unit includes a prohibition unit that prohibits operation of the compressor at or below the predetermined value until the next operation start of the compressor. 10. A brushless DC motor which is directly connected to a compressor connected to a four-way valve and drives the compressor at a variable speed.
(Pulse Width Modulation) An air conditioner equipped with a compressor drive control device including a drive unit driven by a method and a phase detection unit for detecting a pulsating phase of the load torque of the compressor, wherein the compressor drive control device includes: An air conditioner comprising an energization inhibiting means for inhibiting a change in an energized state of the four-way valve during a period in which the phase detecting means detects a pulsating phase of the load torque. 11. The compressor drive control device includes: an energizing unit that energizes the four-way valve to stabilize the position of the four-way valve; and an activation unit that activates the brushless DC motor after the position is stabilized by energizing the energizing unit. The air conditioner according to claim 10, further comprising: an operation command unit that activates the phase detection unit after the start. 12. A brushless DC motor which is directly connected to a compressor and drives the compressor at a variable speed, and driving means for driving the brushless DC motor by a PWM (pulse width modulation) method, wherein an operating frequency of the compressor is constant. When the torque pulsation is not reduced even when the torque pulsation correction is performed, the compressor drive control device is configured to correct the energization duty during one rotation to the brushless DC motor for each predetermined electrical angle when the torque pulsation is equal to or less than the value. Operating control means for controlling the driving of the brushless DC motor such that the torque pulsation correction is interrupted and the compressor is prohibited from operating at an operating frequency equal to or lower than the predetermined value until the next operation. Compressor drive control device. 13. The compressor drive control device according to claim 1, wherein the compressor is a rotary compressor having a one-cylinder structure.