JP2809182B2 - Compressor motor controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for a compressor, and more particularly to a motor for a compressor in which power consumption and vibration of the compressor are reduced by controlling the rotation speed and output torque of the motor. In the control unit.

[0002]

2. Description of the Related Art A conventional motor control device will be described with reference to FIG. 2 showing a schematic structure of a hermetic compressor. Reference numeral 1 denotes a case, which houses an electric element (hereinafter, referred to as a motor) and a compression element. Reference numeral 2 denotes a stator, which is fixed to the case 1. 3 is a rotor and 4 is a shaft, and the rotor 3 and the shaft 4 are press-fitted and fixed. 5 is a main bearing, 6 is an end bearing, which supports the shaft 4, and the main bearing 5 is fixed to the case 1 . Reference numeral 7 denotes a cylinder block which is fastened together with the main bearing 5 and the end bearing 6. 8 is a roller, are fitted to a crank portion of the shaft 4. 9 is a vane, and partitions the cylinder chamber and the suction chamber 10 into the compression chamber 11. Above axis
Receiver 5, end bearing 6, cylinder block 7, roller 8,
The compression element is constituted by a shaft 9. Numeral 12 denotes a vibration isolator, which supports the compressor.

In the conventional hermetic compressor having such a structure, the force of the high-pressure gas in the compression chamber 11 causes the load torque -TG to push back the shaft 4 counterclockwise.
The same torque TG acts on the cylinder block 7 as a reaction force in the clockwise direction.

Here, in the rotating shaft system of the rotor 3 and the shaft 4, as a torque for balancing with the load torque -TG, a motor output torque TM driven from the stator 2 and a rotational inertia torque JR (d ^{2) of the} rotating shaft system. φ / dt ² ) acts.
(Where JR is the mass moment of inertia of the rotating body, d ² φ / d
t ² is the angular acceleration of the rotating body speed variation). The balance of these torques is expressed as JR (d ² φ / dt ² ) + TM = TG, and this relationship is shown in FIG. 3 for one rotation of the compressor.

That is, in the rotation angle region where TG> TM where the load torque TG is large, the rotation shaft system determines the torque difference of TG−TM by d ^2.
By decelerating at an angular acceleration of φ / dt ² , JR (d ²
φ / dt ² ) to release and compensate for the load torque TG
In the rotation angle region where TG is smaller than TG <TM, the torque difference of TM−TG is stored by increasing the rotational axis system with an angular acceleration of d ² φ / dt ² . Therefore, in the rotating shaft system, the rotation speed increases / decreases during one rotation, that is, vibration occurs.

On the other hand, on the non-rotating body side such as the stator 2, the cylinder block 7, the main bearing 5, and the end bearing 6 fixed to the case 1, the load torque TG and the motor output torque −TM are opposite to each other. Acting as a force, a torque difference of TG-TM occurs as in the rotating shaft system. On the non-rotating body side, the inertia torque JST (d ² φ / dt ² ) when the mass inertia moment JST of the non-rotating body fluctuates at an angular acceleration of d ² θ / dt ² with respect to this torque difference (TG−TM). ) And the restoring torque Kθ when the vibration isolating member 12 having the spring constant K is rotationally displaced by θ. These balances are expressed as JST (d ² φ / dt ² ) + Kθ = TG−TM. FIG. 4 shows this relationship for one rotation of the compressor. That is, the torque difference of TG-TM changes to a positive or negative value during one rotation, and this acts as an exciting force, so that the entire non-rotating body side has a rotational displacement (vibration) of θ.
It gives rise to

[0007]

As described above, in the conventional hermetic compressor, the TG-TM as a vibration source is provided on the non-rotating body side.
This fundamental difference in torque has been a major cause of the occurrence of vibrations even if various anti-vibration structures are applied.

[0008] A hermetic seal which forms a part of the refrigeration cycle.
Type compressors have the refrigerating capacity necessary for the refrigeration cycle.
When controlling the rotation speed in accordance with
Movement was a problem.

An object of the present invention is to provide a refrigeration cycle which requires refrigeration.
Controls the number of revolutions according to the capacity to save power and
Controlled so that the actual load torque and motor output torque which varies during one rotation of the over motor is substantially equal, due to this
Of the compression element, which fluctuates momentarily during one revolution
It is an object of the present invention to provide a motor control device for a compressor in which the vibration caused by the difference between the load torque and the motor output torque is reduced.

[0010]

Above object In order to achieve the above, the compression element and this magnitude of the load torque is momentarily fluctuates in one rotation
It is composed of a motor connected to the compression element and frozen
A motor control apparatus for use in a compressor that constitutes a part of the cycle, a position detecting means for detecting a rotational position in one rotation of the rotor of the upper SL motor, rotation position output from the upper Symbol position detecting means Calculating means for calculating the magnitude of the load torque of the compression element during one rotation of the rotor based on information; and at least one of a current and a voltage supplied to the motor based on an output of the calculating means. means for controlling so that the output torque of the load torque and the motor of the compression element the magnitude of the load torque momentarily fluctuates in one rotation is equal control to, the frozen
Required refrigeration capacity detection method to detect the refrigeration capacity required for the vehicle
Based on the information from the step and the required refrigeration capacity detecting means.
The motor is controlled to a rotation speed according to the required refrigeration capacity.
This is achieved by providing a motor control device for a compressor including inverter means for the compressor.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG . 13 compressor, 14 a condenser, 15 key <br/> Yapirarichubu, 16 is an evaporator, the refrigeration cycle <br/> Te by the these is constructed. 17-1, 17-2
Is a load information detector that detects load information applied to the compressor 13. 17-3 is a required refrigeration capacity detector, for example
For example, it detects the ambient temperature of the evaporator 16 and the like.
13 information on required refrigeration capacity is provided. Reference numeral 18 denotes a position detector which detects rotational position information of the compressor 13. 19
Denotes a signal conversion unit, which performs signal processing from each detector, A / D
Performs conversion and the like. Reference numeral 20 denotes a control unit which includes a microcomputer or the like and performs signal processing. Reference numeral 21 denotes a power supply drive unit which adjusts the power supply to the compressor 13 according to a command signal from the control unit 20. 22 is an inverter drive unit, and 23 is an inverter drive unit.
Data, and these constitute the inverter means.
You.

[0012] In hermetic compressors 13 for explaining the above embodiment, for example, as shown in the figure the load information applied to the compressor 13 for detecting the temperature of the condenser 14 of the refrigeration cycle load information detector 17- 1 and a load information detector 17-2 that detects the temperature of the evaporator 16 detect the magnitude of the load that changes with the elapse of the operation time, and the position detector 18 detects the magnitude of the load of the compressor 13 motor during one rotation. The rotation position (rotation angle φ) is detected, and the detected load information and rotation position information signals are output to the control unit 20 via the signal conversion unit 19.

When the load information signal is input, the control section 20 knows the magnitude of the pressure of the refrigerant gas in proportion to the magnitude of the temperature, and thereby determines the magnitude of the load torque during a certain operating time of the compressor. Is determined, and a command signal for controlling the motor so as to drive the compressor with an output torque corresponding to the magnitude of the load torque is output to the power supply drive unit 21.
The control unit 20 to which the position signal has been input calculates and determines the magnitude and timing of the load torque applied to the compressor 13 during one rotation every moment based on the position signal.

This calculates the magnitude of the rotor rotation angle φ at each time interval (period) during one rotation from the position signal,
The magnitude change of the load torque TG can be understood from the magnitude change of the rotation angle φ of the rotor. That is, when the load torque TG changes in a direction to increase, the rotation speed of the rotor decreases, and the rotation angle per unit time decreases. Conversely, when the load torque decreases, the rotation speed of the rotor increases, and the rotation angle per unit time increases. Thereby, the magnitude fluctuation of the load torque can be understood.

The load torque can be calculated by the following equation as described above. If the load torque fluctuating during one rotation is TG, the output torque of the motor is TM, and the rotational inertia torque of the rotating shaft system is JR (d ² φ / dt ² ), the load torque TG
Can be calculated by TG = JR (d ² φ / dt ² ) + TM. Therefore, the output torque TM of the motor is given by: TM = TG−JR (d ² φ
/ Dt ² ).

Based on the calculated load torque TG fluctuating during one rotation and the output torque TM of the motor, the control unit 2
A value of 0 sends a signal to the power supply drive unit 21 to increase the motor output torque TM when the load torque TG is large. In accordance with this signal, the power supply drive section 21 acts to increase the supply voltage (or current) to the motor in the compressor 13 to increase the motor output torque TM, and conversely, the load torque decreases. Control unit 20, the output torque T
It acts to reduce the supply voltage to the motor so as to reduce M.

By performing the control based on the above positional information, the output torque TM of the motor becomes substantially equal to the load torque TG fluctuating during one rotation, so that the fluctuation of the rotation speed of the rotor due to the fluctuation of the load torque is eliminated. Acting on
Reduce vibration. As described above, control is performed such that the motor output torque is adjusted to the magnitude of the load torque in a certain time range of the compressor operating time based on the load information.

In this control, the supply voltage (or current) to the compressor 13 is controlled every moment by determining the fluctuation of the load torque during one rotation based on the position information. that period can be constantly follow to control substantially like correct motor output torque to the magnitude of the load torque (time per interval). That is, in the hermetic compressor 13 of the above embodiment, since the same motor output torque TM is output which is completely synchronized with the waveform change of the load torque TG during one rotation, the two motors are completely balanced, and in the rotating shaft system of the compressor 13, Also, on the non-rotating body side, the excitation torque TG-TM becomes zero, and the vibration excitation source is basically removed, thereby enabling a non-vibration hermetic compressor.

Further, the required refrigerating capacity detector 17-3 detects , for example , the ambient temperature of the evaporator 16 and the like, and performs a refrigerating cycle.
The information signal of the required refrigerating capacity is given to the signal conversion unit 19.
The signal converter 19 performs A / D conversion on the given signal and controls the signal.
Output to the unit 20. The control unit 20 performs the arithmetic processing of this signal.
And issues a command to the inverter 23, controls the inverter 23, motor of the compressor 13 via the inverter drive unit 23
Control the rotation speed of the motor . This allows freezing when detected
It is possible to the rotational speed of the motor <br/> compressor 13 in accordance with the refrigerating capacity required for the cycle, FIG Rukoto power saving
Can be done. The number of rotations of the motor of the compressor 13 is controlled.
Also has the above-mentioned motor output torque control
Therefore, it is possible to control the number of rotations and the load torque in accordance with the load capacity, and it is possible to realize an excellent hermetic compressor with low power consumption and low vibration.

[0020]

The motor control apparatus of a compressor of the present invention according to the present invention calculates the magnitude of the load torque of the compression element during one rotation of the motor <br/> Tarota is supplied to the motor based on the calculated results that current and the actual load torque and the output torque of the motor at least one of the control to the compressor of the voltages
Properly controlled so as to be like a substantially, thereby, the compression element to momentarily vary during the output torque and rotation of the motor
Vibration caused by the difference from the actual load torque can be reduced , and based on the required refrigeration capacity information.
Control the inverter means based on the rotation of the compressor motor.
To control the number of rotations to the number of rotations that matches the required refrigeration capacity
Power savings.
Speed and load torque control according to the load capacity.
Therefore, it is possible to reduce power consumption and vibration .

[Brief description of the drawings]

FIG. 1 is a block diagram of torque control of a hermetic compressor according to the present embodiment.

FIG. 2 is a sectional view showing the structure of a conventional hermetic compressor.

FIG. 3 is a torque curve acting on a rotating shaft system of a conventional hermetic compressor.
Diagram

FIG. 4 shows a torque acting on a non-rotating body side of a conventional hermetic compressor.
Curve diagram

[Description of Signs] 1 ... Case, 2 ... Stator, 3 ... Rotor, 4 ... Shaft, 5 ...
Main bearing, 6: End bearing, 7: Cylinder block, 8: Roller, 9: Vane, 10: Suction chamber, 11: Compression chamber, 12
... vibration isolator, 13 ... compressor, 14 ... condenser, 15 ... capillary tube, 16 ... evaporator, 17-1, 17-2,
17-3: detector, 18: position detector, 19: signal converter, 20: controller, 21: power supply driver, 22: inverter driver, 23: inverter.

Claims (1)

(57) [Claims] The size of the load torque is momentarily fluctuates in one rotation
Composed of connected to the compression element and the compression element motor
Used in the compressor that is part of the refrigeration cycle
A motor control device, position detecting means for detecting a rotational position in one rotation of the rotor of the upper SL motor, during one rotation of the rotor based on the rotation position information outputted from the upper Symbol position detecting means Calculating means for calculating the magnitude of the load torque of the compression element ; and controlling at least one of the current and the voltage supplied to the motor every moment based on the output of the calculating means so that the magnitude of the load torque is 1 means for load torque of the compression element to momentarily vary in rotation and the output torque of the motor is controlled to <br/> equal, necessary to detect the refrigeration capacity required for the refrigeration cycle refrigeration
Based on the information from the capacity detecting means and the necessary refrigeration capacity detecting means.
The motor that controls the motor at a speed corresponding to the required refrigeration capacity
A motor control device for a compressor, comprising: a barter means .