JP2006081270A - Torque control operating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive unit reduced in peak current at overloading when it is at low speed, prevented from the deterioration of drive efficiency, suppressed in the generation of heat, and having no step-out. <P>SOLUTION: The motor drive unit comprises a DC/AC conversion means 2 that outputs a pseudo-AC voltage to a brushless DC motor 1; an induction voltage detecting means 5 that detects an induction voltage of a three-phase armature winding; and a PWM control means 3 that controls a switching element of the DC/AC conversion means 2. The motor drive unit also comprises a torque gain setting means 12, that detects the ripple amount 11 of the DC voltage of the DC/AC conversion means 2 that drives the brushless DC motor 1, and sets a torque gain so that the peak current value of the motor is not higher than a prescribed value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to drive control of a one-piston rotary compressor.

  As motor control devices for controlling the rotational speed of a brushless DC motor, there are a conventional 120 ° energization control method (see Patent Document 1) and a sine wave 180 ° energization control (see Patent Document 2), which are shown in FIG. is there. In FIG. 3, the motor drive device converts DC voltage into pseudo AC voltage and outputs it to the brushless DC motor 1, and magnetic pole position information 7 that detects the rotor position of the brushless DC motor 1. Voltage control means 4 for outputting a predetermined voltage waveform. The PWM control means 3 outputs a duty signal for controlling the applied voltage, frequency, and phase for controlling the rotational speed of the brushless DC motor 1. The DC / AC converting means 2 is composed of six switching elements that open and close at high speed.

  As described above, in the motor driving apparatus configured as described above, the DC voltage is converted into a pseudo AC voltage having a variable frequency and phase by the DC / AC conversion means 2 and output to the brushless DC motor 1. The rotation speed of the brushless DC motor 1 is controlled by changing the frequency / phase (hereinafter referred to as “inverter frequency”) of the pseudo AC voltage output from the DC / AC converting means 2. This inverter frequency is controlled by the PWM control means 3. The PWM control means 3 outputs six base patterns for opening and closing the switching elements of the DC / AC conversion means 2. When the switching elements are opened / closed by these base patterns, the inverter frequency output from the DC / AC converter 2 is controlled.

  When changing the rotational speed of the brushless DC motor 1, the rotational speed of the brushless DC motor 1 is controlled while changing the inverter frequency of the DC / AC converting means 2 based on the rotational phase information of the PWM control means 3.

  Here, the phase detection characteristic of the magnetic pole position information 7 does not depend on the inverter frequency and voltage amplitude output from the DC / AC converter 2, and the induced voltage generated by the brushless DC motor 1 is directly detected by the induced voltage detector 5. The magnetic pole position of the brushless DC motor 1 is estimated and calculated.

  The PWM control means 3 outputs six base patterns based on the rotational phase information. The DC / AC converting means 2 has six switching elements, and includes one switching element in the upper arm and one switching element in the lower arm for each of the U phase, the V phase, and the W phase.

In the motor driving by the conventional brushless DC motor driving device, the brushless DC motor 1 exhibits the original torque performance under the condition that the load torque applied to the brushless DC motor 1 is a small torque, and has good speed control performance. Therefore, the speed followability is good even for a considerable speed pulsation, and sufficient high-speed response can be secured. Since the configuration of the control circuit and the motor operation program are simple, there is a great merit that the cost of the entire system including the control circuit can be reduced.
Japanese Patent No. 2642357 JP 7-245982 A Japanese Patent Laid-Open No. 7-337079

  However, when the brushless DC motor 1 is in a low speed region or when it is overloaded, the noise and vibration of the motor increase. Therefore, the torque gain is set to a large value to suppress the vibration. Will increase. Under such circumstances, drive efficiency deteriorates, heat is generated, power components burn out, and in the worst case, the motor steps out and leads to damage to the motor equipment.

  In order to solve the above-described conventional problems, the torque control operation device of the present invention adjusts the torque gain to reduce the noise and vibration that increase when the brushless DC motor is in a low speed region or an overload, thereby reducing the peak current. An object of the present invention is to provide a reliable one-piston rotary compressor torque control operation device that exhibits the original characteristics of a motor even in the use of a high load torque region.

  The DC voltage of the DC / AC converting means for driving the brushless DC motor is detected, the ripple amount of the detected DC voltage is calculated, and the target DC voltage ripple amount is calculated from the temperature life of the aluminum electrolytic capacitor for voltage doubler rectification. If it is set and the torque gain is appropriately adjusted so as to approach the target value, the peak current of the motor can be reduced, and a highly reliable torque control operation device for a one-piston rotary compressor can be provided.

  The present invention detects a DC voltage of a DC / AC converter that drives a brushless DC motor when the brushless DC motor is in a low speed region or an overload, and determines a target DC from a temperature life of an aluminum electrolytic capacitor for voltage doubler rectification. Set the voltage ripple value, adjust the torque gain to approach that value, prevent the peak current from increasing, suppress the vibration and heat of the motor, do not step out and use in the high load torque range Also, it is possible to provide a highly reliable torque-controlled operation device for a single-piston rotary compressor that exhibits the characteristics inherent in the motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a control block diagram of the present invention.

  A DC voltage detection means 8 for detecting the DC voltage of the DC / AC conversion means 2 is provided in the configuration of FIG. 3 of the conventional example, and a DC voltage ripple amount calculation means 10 for calculating a ripple amount from the detected DC voltage 9 is provided. And a torque gain setting means 12 for adjusting the torque gain based on the DC voltage ripple amount 11 output from the DC voltage ripple calculating means 10. The torque gain adjustment amount 13 is fed back to the voltage control means 4. Is done.

The torque gain setting means 12 sets the torque gain adjustment amount 13 as a target value with a DC voltage ripple amount A% determined from the temperature life of the aluminum electrolytic capacitor for the purpose of torque control and voltage doubler of the one-piston rotary compressor. And proportional control that adjusts so as to be proportional to the difference between the current DC voltage ripple amount obtained from the ripple voltage calculation means 10. At that time, the torque gain adjustment amount Gn is
Gn + 1 = Gn = Gmax (0 ≦ A <An)
Gn + 1 = Gn + K (Amax−An) (An ≦ A)
It is expressed. An is a current value obtained from the DC current detecting means 8.

  As shown in FIGS. 2A and 2B, the rise of the DC voltage ripple amount makes the torque gain adjustment amount constant at Gmax. Then, the DC voltage ripple amount increases with a certain slope An / T1 (T1> T> 0, An> A> 0). When An is reached, the torque gain adjustment amount is manipulated as shown in FIG. Then, the DC voltage ripple amount is adjusted according to the relationship of A = f (t), and at the time T2 (T2> T1> 0) which is a convergence point, the target DC voltage ripple amount Amax (Amax> An > 0, Amax = f (T2)) Proportional control to converge smoothly, preventing increase in peak current, suppressing motor vibration and heat, and stable one piston without causing step-out The torque control operation of the rotary compressor can be performed.

  The present invention relates to a rotation control technique of a DC brushless motor used for a compressor (compressor) or the like of an air conditioner, and in particular, can further reduce vibration and noise.

FIG. 3 is a control block diagram of the torque control operation device in Embodiment 1 of the present invention (A) The graph which shows the time change of the adjustment amount of the torque gain of the torque control driving device in Embodiment 1 of the present invention (b) The graph which shows the time change of the ripple amount of the DC voltage of the DC / AC conversion means Control block diagram of a conventional motor drive device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless DC motor 2 DC alternating current conversion means 3 PWM control means 4 Voltage control means 5 Inductive voltage detection means 6 1 Piston rotary compressor 7 Magnetic pole position information 8 DC voltage detection means 9 DC voltage value information 10 DC voltage ripple amount calculation means 11 DC Voltage ripple amount 12 Torque gain setting means 13 Torque gain adjustment amount

Claims (1)

A one-piston rotary compressor connected to a brushless DC motor; a DC / AC converter that includes a switching element; converts a DC voltage into an AC voltage based on a PWM signal by opening and closing the switching element; Inductive voltage detection means for detecting the induced voltage of the motor, voltage control means for outputting a voltage waveform based on magnetic pole position information output from the induced voltage detection means, and PWM control for converting the voltage waveform to the PWM signal And a torque gain of the brushless DC motor is set based on a DC voltage ripple amount of the DC / AC converting means detected by the DC voltage detecting means with respect to a rotational load torque fluctuation of the one-piston rotary compressor. , Make the peak current of the motor below the specified value Torque control operation apparatus characterized by having a Rukugein setting means.

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