JP2005192268A - Torque control driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable torque control driving device for a single-piston rotary compressor which restrains noise and vibration even in its use in a low-speed range with a high load torque, and restrains the deterioration of drive efficiency and increase in the heat generation, and prevents step out. <P>SOLUTION: This device is provided with a torque gain setting means 10, which sets the torque gain of a voltage control means 4 for the rotational torque ripples of the one-piston rotary compressor 6, based on a specified physical amount, thereby correcting it. Hereby, this can restrain deterioration of drive efficiency and increase in heat generation, even in its use at a low-speed range with high a load torque by optimally setting the torque gain and reducing the peak current. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to drive control of a one-piston rotary compressor for an air conditioner using a brushless DC motor.

  As motor driving 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).

  FIG. 8 is a conventional general control block diagram. In FIG. 8, the motor operating device is composed of six switching elements that open and close at high speed, converts DC voltage into pseudo AC voltage and drives brushless DC motor 1, and rotor position of brushless DC motor 1. The voltage control means 4 for controlling the output voltage based on the magnetic pole position information 7 which is the output of the induced voltage detection means 5 for detecting the voltage, and the applied voltage / frequency for controlling the rotation speed of the brushless DC motor 1 from the output of the voltage control means 4 A PWM control means 3 that outputs to the DC / AC conversion means 2 as a duty signal for controlling the phase.

  In the motor operating 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, and the rotational speed of the brushless DC motor 1 is It 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. The inverter frequency output from the DC / AC converting means 2 is controlled by opening and closing the switching elements by these base patterns.

  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 unit 3 outputs six types of 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 ensured. 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 Laid-Open No. 1-8890 JP 7-245982 A Japanese Patent Laid-Open No. 7-337079

  However, in the conventional configuration, since the noise and vibration of the brushless DC motor 1 increases when the rotation of the one-piston rotary compressor is in a low speed region or when it is overloaded, the torque gain is set to be large and vibration suppression is suppressed. However, if the gain is increased, the current flowing through the motor increases. Under such circumstances, there is a risk that drive efficiency will deteriorate, heat generation will increase, and in the worst case, step-out will occur, leading to destruction of power components and damage to motor equipment.

  The present invention solves the above-described conventional problems, and suppresses noise and vibration even in the use of a high load torque and low speed region, and also suppresses deterioration of driving efficiency and increase of heat generation, and prevents out-of-step. An object of the present invention is to provide a torque control operation device for a high-speed one-piston rotary compressor.

  In order to solve the above-described conventional problems, the torque control operation device of the present invention is provided with a torque gain setting means, and the torque gain of the voltage control means is set to a predetermined physical quantity with respect to the rotational load torque fluctuation of the one-piston rotary compressor. It is set and corrected based on this. Thus, by setting the torque gain optimally and reducing the peak current, it is possible to suppress deterioration in drive efficiency and increase in heat generation even in the use of a high load torque / low speed region.

  The torque control operation device of the present invention reduces the peak current of the motor and suppresses noise and vibration even in the use of a high load torque and low speed region, and suppresses deterioration of driving efficiency and increase of heat generation with high efficiency and high-efficiency. A highly reliable one-piston rotary compressor drive can be realized.

  According to a first aspect of the present invention, there is provided a DC / AC converter that converts a DC voltage into an AC voltage by opening and closing a switching element, an induced voltage detector that detects an induced voltage of a motor, and magnetic pole position information output from the induced voltage detector. A driving device for driving a brassless DC motor connected to a one-piston rotary compressor, comprising voltage control means for controlling an output voltage based on the PWM control means for converting the output voltage into a PWM signal. Installed to optimally set the torque gain of the voltage control means based on a predetermined physical quantity against the rotational load torque fluctuation of the 1-piston rotary compressor, thereby preventing increase in peak current, suppressing noise and vibration, and driving Reduces efficiency and heat generation, prevents out-of-step occurrence and increases reliability

  The second invention is particularly the first invention, and includes a current sensor for detecting a phase current of the brassless DC motor, and the predetermined physical quantity is a current value detected by the current sensor and a demagnetizing current of the motor to be used. By detecting the phase current flowing through the brushless DC motor by setting the output of the adjustment amount of proportional control performed from the difference, the target motor current value is set from the value of the demagnetizing current of the motor to be used, and approaches that value. Thus, the torque gain is adjusted to reduce the peak current and keep it within the demagnetizing current value of the motor. As a result, the above-described effects can be obtained.

  The third invention is the first invention in particular, and includes temperature detection means for detecting the outside air temperature and the temperature of the one-piston rotary compressor, and the predetermined physical quantity is a load state of the motor derived from the correlation between the two temperatures. The same effect can be obtained by setting the torque gain optimally in accordance with the output of the region identification value indicating.

  The fourth aspect of the invention is the first aspect of the invention in particular, comprising temperature detection means for detecting the temperature of the heat exchanger and the temperature of the one-piston rotary compressor, and the predetermined physical quantity of the motor derived from the correlation between the two temperatures. A similar effect can be obtained by optimally setting the torque gain in accordance with the value of the region identification indicating the load state.

  The fifth aspect of the invention is particularly the first aspect of the invention, wherein the predetermined physical quantity is an output indicating the load state of the motor derived from the vibration value information of the heat exchanger detected using a torque gauge. A similar effect can be obtained by optimally setting the gain.

  The sixth invention is particularly the first invention, wherein the predetermined physical quantity is an output value indicating the load state of the motor derived from vibration value information of the one-piston rotary compressor detected using an optical vibration sensor. A similar effect can be obtained by optimally setting the torque gain according to the above.

  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)
A torque control operation device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a control block diagram of the first embodiment.

  In the configuration of the conventional example, the phase current detection means 8 is provided on the connecting line connecting the circuit of the DC / AC conversion means 2 to the brushless DC motor 7 to detect the phase current of the motor, and the phase current output from the phase current detection means. Torque gain setting means 10 for adjusting the torque gain based on the value information 9 is provided, and the torque gain adjustment amount 11 is fed back to the voltage control means 4.

In the torque gain setting means 10, the torque gain adjustment amount 11 is adjusted so as to be proportional to the difference between the target value and the current value obtained from the phase current detection means 8 with the motor demagnetization current value I _MAX as a target. When the proportional control is used, the torque gain adjustment amount Gn is
G _{n + 1} = Gn = G _MAX (0 ≦ I <Ia)
G _{n + 1} = Gn + K (I _MAX −In) (Ia ≦ I)
It is expressed. Here, In is a current value obtained from the phase current detection means 8, and Ia is a current value at a point T1 at which the torque gain starts to be reduced from G _MAX .

Rise of current as in FIG. 2 (a) (b) causes the torque gain adjustment amount constant at G _MAX. Then, the current value increases with a certain slope Ia / T1 (T1>T> 0, Ia>I> 0), and when Ia is reached, the torque gain adjustment amount is manipulated as shown in FIG. The current value is adjusted according to the relationship of I = f (t), and at the time T2 (T2>T1> 0) which is a convergence point, the target current value I _MAX (I _MAX >Ia> 0, I _MAX = f (T2)) Proportional control so that it converges smoothly, prevents an increase in peak current, suppresses motor vibration and heat generation, and is stable without causing step-out. Torque control operation can be performed.

(Embodiment 2)
A torque control operation device according to Embodiment 2 of the present invention will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a control block diagram of the second embodiment.

The configuration of the conventional example is provided with the temperature detection means 13 and the outside air temperature detection means 14 of the 1-piston rotary compressor 6, and the outputs thereof are 1-piston rotary compressor temperature information 15 and outside air temperature information 16. The temperature detecting means 13 and the outside air temperature detecting means 14 of the present embodiment adopt a method using a known thermistor and a partial pressure of resistance.

As shown in FIG. 4 (a), the 1-piston rotary compressor temperature information 15 is Th and the outside air temperature information 16 is To, and the difference Th−To = Kn is obtained. Kn is outside the range of the overload regions K4 and K5. In some cases, the torque gain is increased. The increase is stepwise for each value of Kn. Here, Kn is represented by a relationship of K5>K4>K3>K2>K1> 0. Then, as shown in FIG. 4B, the torque gain Gn starts from the initial value G0. When Kn is up to K1, the gradient is (G1-G0) / K1, and further up to K2, (G2-G1) / Step control is performed with the gradient of (K2-K1) and with the gradient of (G3-G2) / (K3-K2), and the value is increased to G _MAX . Thereafter, when the temperature rises and reaches the range of the overload region K4, it is determined that the load of the brassless DC motor 1 is overloaded and the peak current is increased, the torque gain is adjusted, and the initial value G0 is reached. Until the peak current is decreased rapidly with a slope (G5-G4) / (K5-K4). When K5 is reached beyond K4, the torque gain amount is brought close to zero. At this time, Gn is represented by the relationship of G3 = G4>G2>G1> G0 = G5> 0, G3 = G4 = G MAX. As described above, the peak current can be reduced by lowering the torque gain stepwise, and a stable torque control operation of the one-piston rotary compressor can be performed without damaging the motor device.

  Further, as shown in FIG. 5, the temperature rise value of the one-piston rotary compressor 6 can be calculated by detecting the heat exchanger temperature instead of detecting the outside air temperature, and the torque gain can be calculated more accurately from the value. Can be adjusted.

(Embodiment 3)
A torque control operation apparatus according to Embodiment 3 of the present invention will be described with reference to FIGS.

  FIG. 6 is a control block diagram of the third embodiment.

  The configuration of the conventional example is provided with a torque gauge as the vibration detection means 19 for picking up the vibration of the heat exchanger 12, and the vibration information 20 is fed back to the torque gain setting means 10.

As already described, the brassless DC motor 1 suppresses vibration by increasing the torque gain when in a low speed region or in an overload state. In the present embodiment, as shown in FIG. 7, the vibration magnitude is set to A5>A4>A3>A2>A1> 0, and the vibration information 20 of the heat exchanger 12 is decreased from a certain value A5 during vibration suppression. If A4 is obtained, step control as in the second embodiment is used, and the torque gain is decreased with the gradient (G _MAX -G _A4 ) / (A5-A4). Similarly, if reduced to _A3, with a slope of _{(G A4 -G A3) / (} A4-A3), When it is reduced to _A2, the _{(G A3 -G A2) / (} A3-A2) the slope, and if it decreases to A1 by using a step control to reduce the torque gain with a slope of _{(G A2 -G A1) / (} A2-A1), to fine adjustment of the torque gain, peak current It is possible to perform a stable torque control operation of the one-piston rotary compressor that does not exceed.

  Further, by using an optical vibration sensor as the vibration detection means 19, vibration can be detected in the same manner, and the torque gain can be adjusted using the step control described above.

As described above, the torque control operation device according to the present invention can reduce vibration and noise even with a compressor having a large torque fluctuation, and thus can be widely applied to devices using a compressor such as an air conditioner or a refrigeration refrigerator. Can do.

FIG. 3 is a control block diagram of the torque control operation device according to Embodiment 1 of the present invention. (A) The graph which shows the time change of the torque gain adjustment amount of the torque control operation apparatus in Embodiment 1 of this invention (b) The graph which shows the time change of an electric current value similarly. Control block diagram of torque control operation device in Embodiment 2 of the present invention (A) The graph which shows the relationship between the difference of the compressor of the torque control operating apparatus in Embodiment 2 of this invention and external temperature, and a load area | region (b) Same as the above, The relationship between the difference of a compressor and external temperature and torque gain Graph showing Another control block diagram of the torque control operation device in Embodiment 2 of the present invention Control block diagram of torque control operation device in Embodiment 3 of the present invention The graph which shows the relationship between the vibration value of the heat exchanger of the torque control operation apparatus in Embodiment 3 of this invention, and a torque gain. Control block diagram of a conventional motor driving device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brassless DC motor 2 DC / AC conversion means 3 PWM control means 4 Voltage control means 5 Induced voltage detection means 6 1 Piston rotary compressor 7 Magnetic pole position information 8 Phase current detection means 9 Motor current value information 10 Torque gain setting means 11 Torque gain adjustment 11 Quantity 12 Heat exchanger 13 1-piston rotary compressor temperature detecting means 14 Outside air temperature detecting means 15 1-piston rotary compressor temperature information 16 Outside air temperature information 17 Heat exchanger temperature detecting means 18 Heat exchanger temperature information 19 Heat exchanger vibration detecting means 20 Heat exchanger vibration information

Claims (6)

DC / AC conversion means for converting DC voltage to AC voltage by opening and closing the switching element, induced voltage detection means for detecting the induced voltage of the motor, and output voltage based on magnetic pole position information output from the induced voltage detection means A driving device for driving a brassless DC motor connected to a one-piston rotary compressor, comprising a voltage control means for controlling and a PWM control means for converting an output voltage into a PWM signal. A torque control operation device characterized in that a torque gain of the voltage control means is set and corrected based on a predetermined physical quantity with respect to a rotational load torque fluctuation of a piston rotary compressor. A current sensor for detecting a phase current of a brassless DC motor is provided, and the predetermined physical quantity is an output of an adjustment amount of proportional control performed from a difference between a current value detected by the current sensor and a demagnetizing current of a motor to be used. The torque control operation device according to claim 1. The apparatus includes temperature detection means for detecting the outside air temperature and the temperature of the one-piston rotary compressor, wherein the predetermined physical quantity is an output of region identification indicating a motor load state derived from the correlation between the two temperatures. The torque control operation device according to claim 1. Temperature detecting means for detecting the temperature of the heat exchanger and the temperature of the one-piston rotary compressor; and the predetermined physical quantity is an output of region identification indicating a load state of the motor derived from the correlation between the two temperatures. The torque control operation device according to claim 1, wherein The torque control operation device according to claim 1, wherein the predetermined physical quantity is an output indicating a load state of a motor derived from vibration value information of a heat exchanger detected using a torque gauge. The torque control operation according to claim 1, wherein the predetermined physical quantity is an output indicating a load state of a motor derived from vibration value information of a one-piston rotary compressor detected using an optical vibration sensor. apparatus.

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