JP2008072777A - Controller for single-piston rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply an inverter controller performing stabilized torque control that will not cause step-outs for rapid variation of DC voltage in a brushless DC motor controller. <P>SOLUTION: The amount of ripples for a DC voltage is detected by a detection means 11 for detecting the amount of ripple of a DC voltage; and when the amount of ripple reaches some level calculated from the temperature lifetime of an electrolytic capacitor, an alteration designating/transmitting means 13 issues instructions to a microcomputer 4 to shorten the resampling period of DC voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inverter control device aimed at stabilizing 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 Documents 2 and 3).

In the motor drive by the conventional brushless DC motor driving device shown in FIG. 3, the brushless DC motor exhibits its original torque performance and good speed control when the load torque applied to the brushless DC motor is a small torque. The performance and the speed followability are good even for a considerable speed pulsation, and it is possible to ensure sufficient high speed response. 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 is in a low speed region or overloaded, the noise and vibration of the motor will increase, so torque gain is set to a large value and vibration suppression is performed. Will increase. In addition, although a constant gain amount is determined for each rotation frequency of the brushless DC motor, it cannot be varied depending on the driving load and environment at that time, so that there may be insufficient torque or excessive torque. When excessive torque, that is, when the torque ON / OFF difference is large, ripples occur in the DC voltage. If the amount of ripple is large, the difference between the maximum and minimum MIN of the DC voltage is large, and in such a situation, the worst case will result in step-out and lead to breakage of the motor device.

  The present invention solves the above-described conventional problem, and detects the DC voltage ripple amount of the DC / AC conversion means detected by the DC voltage detection means, and sets the sampling period of the DC voltage based on the detected ripple amount. It is an object of the present invention to provide a highly reliable control device for a one-piston rotary compressor that can be shortened to improve voltage withstand capability and avoid step-out.

  In order to solve the above-described conventional problems, the present invention is provided with a means for detecting a ripple amount of a DC voltage, and an attempt is made to adjust the sampling period of the DC voltage from the detected value.

  As a result, even when the brushless DC motor has an excessive torque gain amount that suppresses noise and vibration that increases when the brushless DC motor is in a low speed region or an overload, and the amount of change in the DC voltage increases, the DC voltage change resistance can be improved. Therefore, it is possible to provide a highly reliable control device for a one-piston rotary compressor that can avoid step-out.

DC voltage ripple amount detection means is provided, and the DC voltage sampling period is adjusted based on the detected value to improve the DC voltage change tolerance, and step out can be avoided.
A highly reliable control device for a one-piston rotary compressor can be provided.

  According to the first aspect of the present invention, the brushless DC motor is in a low speed region or is overloaded, and the DC voltage sampling period is adjusted based on the detected DC voltage ripple amount to be resistant to step-out and reliable. A control device for a high one-piston rotary compressor can be provided.

  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)
FIG. 1 is a control block diagram of the present invention, and FIG. 2 is a graph showing its characteristics. A first embodiment of the present invention will be described with reference to FIGS.

  In addition to the configuration of the conventional example, a DC voltage detecting unit 11 for detecting the DC voltage of the DC / AC converting unit 2 is provided, and a DC voltage ripple amount calculating unit 12 for calculating a ripple amount from the detected DC voltage is provided. And an instruction transmission means 13 for transmitting an instruction to change the sampling cycle of the DC voltage to the microcomputer based on the DC voltage ripple amount output from the DC voltage ripple calculation means 12.

  When the DC voltage ripple amount exceeds a certain value A% determined from the step-out tolerance and the temperature rise of the electrolytic capacitor, the DC voltage resample period is changed from R1 to R2 (R1> R2). The step-out tolerance (DC voltage change rate) σ is a well-known technique for torque control of a one-piston rotary compressor. Σ ≦ RCV * DCMin / TRCV RCV = regenerative voltage judgment constant, TRCV = DC voltage resample period It will become stronger.

  However, the following adverse effect that shortens the resample time of the DC voltage occurs. The brushless DC motor is in the high-speed rotation region when the DC voltage resample used to detect whether it is in the regenerative voltage interval is small, and the induced voltage for positioning the motor even in the regenerative voltage interval when the motor regenerative voltage is large. Start detecting. In that case, since the regenerative voltage is detected, an erroneous detection of the induced voltage zero-crossing point occurs, causing a step-out phenomenon. Therefore, when the rotation speed of the brushless DC motor changes and the DC voltage ripple amount becomes a certain value A% or less, the DC voltage resample period is changed to R1.

  As a result, even if the brushless DC motor 1 has an excessive torque gain amount that suppresses noise / vibration that increases when the brushless DC motor 1 is in a low speed region or an overload, and the amount of change in the DC voltage increases, the DC voltage change tolerance is improved. And step-out can be avoided.

  The present invention relates to a rotation control technology of a motor (for example, a DC brushless motor) used for a compressor (compressor) of an air conditioner, and more particularly, it becomes stronger against a change amount of a DC voltage and avoids step-out. can do.

Control block diagram of one-piston rotary compressor according to Embodiment 1 of the present invention (A) The graph which shows the time change of the DC voltage ripple amount of the control apparatus of 1 piston rotary compressor as described in Embodiment 1 of this invention (b) The resampling period of DC voltage as described in Embodiment 1 of this invention Graph showing changes in Drive control block diagram of a conventional one-piston rotary compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Reactor 3 Diode bridge 4 Microcomputer 5 DC alternating current conversion means to convert DC voltage into pseudo AC voltage 6 1 piston rotary compressor 7 Brushless DC motor 8 Induced voltage detection means 9 Voltage control means 10 PWM control means 11 DC voltage detection Means 12 DC voltage ripple amount computing means 13 Sampling cycle change instruction

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, and supplies the AC voltage to the brushless DC motor; 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 DC voltage ripple of the DC / AC converting means detected by the DC voltage detecting means with respect to fluctuations in rotational load torque of the one-piston rotary compressor. Specially set based on volume Control device 1 piston rotary compressor for a.

Images