JP5291325B2 - Control device for motor connected to compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a motor connected to a compressor that can suppress vibrations, inexpensively. <P>SOLUTION: The torque controller of the motor 2 for the compressor includes a current sensor 10 for detecting the motor current, a speed/position estimating portion 11 for estimating motor rotation position from the motor current, a speed PI control portion 12 for computing the average load torque of the motor, and a load torque compensating portion 13 for storing a normalizing torque pattern. The controller calculates the compensating torque, by multiplying the average torque by the normalization torque pattern to correct a current command with respect to the motor 2. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention opens to a controller for a motor connected to a compressor for reducing rotational vibration based on an imbalance between the driving torque and load torque of the compressor.

  In the compressor, a steady load torque fluctuation occurs due to a change in refrigerant gas pressure in each stroke of suction, compression, and discharge during one rotation. On the other hand, since the drive motor connected to the compressor is operated so as to generate a constant drive torque during one rotation, a rotation speed fluctuation is caused due to an imbalance between the drive torque and the load torque. As a result, vibration is generated.

  In order to prevent such vibration, for example, Patent Document 1 discloses an electric motor that drives a load whose load torque changes with periodicity, and one cycle of fluctuation of the load torque is obtained by dividing it into n. Means for detecting the speed for each of the n regions, and a control device for adjusting and controlling the current or voltage applied to the motor so that the speed of the motor matches the command speed using the speed data detected by the means; In the speed control method, the speed detection is performed for each divided area, and at least one of the n data of voltage or current applied to the electric motor is corrected and controlled so as to reduce the rotational pulsation. In order to prevent the motor output torque from being inconsistent with the load torque, the average speed of the load torque fluctuation period or a longer period is detected. Average speed detection means, average deviation speed data creation means for creating average deviation speed data for each area from the average speed data and command speed obtained from the average speed detection means, and average deviation speed data creation means A speed control device for an electric motor having correction means for correcting current command data or voltage command data so as to reduce the average deviation speed of at least one of the divided areas based on the average deviation speed data created by It is disclosed.

  Further, Patent Document 2 corresponds to this rotation angle based on the storage means that stores in advance a coefficient that changes in a pattern corresponding to the load torque change pattern during one rotation of the compressor, and the rotation angle of the motor. An output means for outputting a coefficient from the storage means; a multiplication means for multiplying the average voltage command by the coefficient output from the storage means and forming a new voltage command; and driving the motor based on the new voltage command; A compressor motor control device is disclosed in which the torque of the motor is made to follow a change in load torque during one rotation.

  Furthermore, Patent Document 3 stores a torque pattern corresponding to fluctuations in load torque for a motor that drives a load whose load torque periodically changes during one rotation, and determines the torque according to the rotational position of the rotor. In the motor control device that performs control, if the torque pattern is always fixed regardless of the motor rotation speed, hunting occurs because sufficient vibration suppression capability cannot be exhibited in a wide rotation speed range. The average number of rotations in one rotation of the motor is detected, and this number of rotations is compared with the target number of rotations to determine whether the variation state of the number of rotations is a stable state or a transient state. Select a torque pattern, and if it is in a transient state, select the torque pattern according to the average speed to suppress frequent changes in the torque pattern and maintain the motor speed in a stable state. And so as not to generate Nchingu, motor control method and a motor control apparatus is disclosed.

Japanese Patent No. 1966999, Japanese Patent Publication No. 6-97868 JP 2001-295769 A JP 2003-70282 A

  However, the speed control device for an electric motor and the speed control method for the electric motor disclosed in Patent Document 1 need to detect the speed for each divided section, and need to individually control the voltage or current value for each section. In addition, it is necessary to correct the voltage or current value in at least one section, and the control device is required to have a large processing performance, thereby increasing the cost.

  In addition, since the compressor motor control device disclosed in Patent Document 2 causes the output torque of the motor to follow the change of the load torque, the relationship between the voltage applied to the motor and the torque of the motor is simulated in advance. It was necessary to calculate and development took time.

  Furthermore, in the motor control method and the motor control device disclosed in Patent Document 3, if the change of the average torque during one rotation of the motor is not taken into consideration when changing the torque pattern, the average torque compensation amount is changed by the change of the torque pattern. In order to prevent the occurrence of hunting when the average torque during one rotation of the motor increases and decreases, the fluctuation in the rotation speed occurs and the value is near the set rotation speed at which the torque pattern change is executed. It is necessary to prepare a lot of torque patterns according to the rotation speed.

  The present invention has been made on the basis of such a technical problem, and it is difficult to suppress vibration, such as at a low cost and at a high compression ratio, or when changing the torque pattern, the shock is reduced to ensure vibration. It aims at providing the control apparatus of the motor connected to the compressor which enabled it to suppress.

One aspect of the present invention made for this purpose is :
A motor control device that is connected to a compressor and controls the rotational speed of the motor by an AC power source and an inverter ,
A speed control unit for setting a current command value to be supplied to the motor via the inverter in order to rotate the motor at a target rotational speed;
A current sensor for detecting an actual current value supplied to the motor;
With estimates the rotational position of the motor from the actual current value, and the rotational position estimation unit having the actual rotation speed calculation function corresponding to the rotational position of the motor from the current value,
An average torque calculator that calculates the average load torque of the motor from the difference between the rotational speed command value and the actual motor rotational speed obtained via the rotational position estimating unit from the actual current value detected by the current sensor When,
A torque pattern storage unit that stores a normalized torque pattern that serves as a reference for varying the output torque of the motor according to the rotational position of the motor;
Torque for correcting a current value supplied to the motor by generating a compensation torque pattern for varying the output torque of the motor according to the rotational position of the motor by the product of the average load torque and the normalized torque pattern A control unit;
Characterized by comprising a.

Also , 2 of the present invention is
A motor control device that is connected to a compressor and controls the rotational speed of the motor by an AC power source and an inverter ,
A speed control unit for setting a current command value to be supplied to the motor via the inverter in order to rotate the motor at a target rotational speed;
A current sensor for detecting an actual current value supplied to the motor;
With estimates the rotational position of the motor from the actual current value, and the rotational position estimation unit having the actual rotation speed calculation function corresponding to the rotational position of the motor from the current value,
An average torque calculator that calculates the average load torque of the motor from the difference between the rotational speed command value and the actual motor rotational speed obtained via the rotational position estimating unit from the actual current value detected by the current sensor When,
A torque pattern storage unit storing a plurality of normalized torque patterns serving as a reference for varying the output torque of the motor according to the rotational position of the motor;
Based on the product of one normalized torque pattern selectively obtained from the torque pattern storage unit based on the operating state of the motor and the average load torque, the output torque of the motor is determined according to the rotational position of the motor. A torque control unit for generating a compensation torque pattern for changing according to a load and correcting a current value supplied to the motor;
It is provided with.

  Here, the normalized torque pattern is a coefficient for changing the output torque of the motor for each rotational position of the motor, and the angle during one rotation of the motor is divided into a plurality, and the coefficient is preliminarily set in each division. It is set. Since the average load torque of the rotating motor can be calculated by the average torque calculation unit from the current value detected by the current sensor, the product of the average load torque and the normalized torque pattern is calculated by the torque control unit. Then, it is possible to generate a compensation torque pattern in which the normalized torque pattern is increased or decreased according to the rotation state (load magnitude) of the motor at that time. Similar to the normalized torque pattern, this compensation torque pattern is obtained by classifying a plurality of angles during one rotation of the motor and setting coefficients in each class. By using this compensation torque pattern and correcting the current value supplied to the motor, the current supplied to the motor fluctuates based on the compensation torque pattern according to the rotational position of the motor, and corresponds to the compressor load state. It will be a thing.

  In such a configuration, a normalized torque pattern is stored in advance in the torque pacoon storage unit, and the current value supplied to the motor is corrected using this, so that torque control can be easily performed, and smooth control is possible. . Further, since the current supplied to the motor can be easily obtained from the relational expression between torque and current, the torque pattern can be set with the output torque value as it is by performing motor control with a current command. Therefore, it is not necessary to calculate the voltage value by simulation or the like, and development is easy.

  When a plurality of normalized torque patterns are used, the torque control unit is a normalized torque pattern corresponding to the magnitude of the average load torque of the motor calculated by the average torque calculation unit from the plurality of normalized torque patterns. And generating the compensation torque pattern, a normalization torque pattern that generates a large compensation torque when the average load torque is large and a small compensation torque when the average load torque is small can be employed. Thus, a speed close to the target speed can be obtained, and protection control such as driving avoidance can be performed.

  Similarly, when a plurality of normalized torque patterns are used, the position estimation unit has a rotation speed calculation function corresponding to the rotation position of the motor from the current value, and the torque control unit includes the plurality of normalization torque patterns. By selecting a normalized torque pattern corresponding to the rotation speed fluctuation range of the motor from the normalized torque pattern and generating the compensation torque pattern, as described above, by each process of suction, compression, and discharge during one rotation In a compressor where load torque fluctuations occur, the vibration is large where the pressure difference is large, and the vibration is small when the difference is small. Therefore, the vibration state of the compressor can be estimated by looking at the rotation speed fluctuation range. it can. Accordingly, by selecting a normalized torque pattern corresponding to the motor speed fluctuation range in this way, a target speed corresponding to the load state can be obtained, and protection control such as driving avoidance can be performed in the case of excessive vibration. .

  Further, similarly, when a plurality of normalized torque patterns are used, the torque control unit performs normalized torque corresponding to the rotation position and rotation speed of the motor estimated by the position estimation unit from the plurality of normalized torque patterns. By selecting the pattern and generating the compensation torque pattern, the rotation speed is accelerated / decelerated due to load fluctuations, but when the compression ratio is small, the load torque has a peak at a small rotation angle and the compression ratio is high. By the way, since a peak occurs at a large rotation angle, it is possible to see a pattern corresponding to the shape of the load torque with high and low pressure in the compressor, and since a normalized torque pattern that matches the load pattern can be selected directly, A highly accurate selection can be made.

  Similarly, when a plurality of normalized torque patterns are used, the torque control unit selects a normalized torque pattern corresponding to the motor current peak value detected by the current sensor from the plurality of normalized torque patterns, By generating the compensation torque pattern, in the compressor, the motor is always controlled to rotate at a constant speed. Therefore, the current increases as the load increases, and the current decreases as the load decreases. By selecting a corresponding normalized torque pattern from a plurality of normalized torque patterns depending on the magnitude of the motor current peak value, it is possible to easily select a normalized torque pattern that generates a compensation torque pattern.

When the normalized torque pattern is selected in this way, a switch is made from a specific normalized torque pattern to a new normalized torque pattern, and the torque control unit is configured to switch from one of the plurality of normalized torque patterns to another normalized torque pattern. By calculating the value of the torque difference between the two patterns in the state of switching to the torque pattern, and generating the compensation torque pattern while decreasing the value of the torque difference before switching at a constant rate, Switching is not performed all at once, and switching can be performed while preventing vibration due to a large increase / decrease in current value due to pattern switching, speed shock, and the like.

  Similarly, the torque control unit is configured to switch the load torque of both patterns at the rotational position of the motor estimated by the position estimation unit in a switching state from one of the plurality of normalized torque patterns to another normalized torque pattern. When the switching is performed at a small angle, the vibration occurs when the pattern is switched because the transient speed fluctuation, current vibration, etc. increase due to the switching at the position where the load torque is large. In this way, by switching at an angle where the load torque of both patterns at the rotational position of the motor is small, the current to the motor is small at the angle where the load torque is small, and therefore vibration due to it is less likely to occur. Shocks such as speed fluctuations and current vibrations can be reduced.

  The torque control unit sets a threshold value for selecting the other normalized torque pattern from one of the other normalized torque patterns in a switching state from one of the plurality of normalized torque patterns to another normalized torque pattern. The threshold value for selecting one normalized torque pattern is set to one normalized value when switching from one of the plurality of normalized torque patterns to one normalized torque pattern. By judging from the torque pattern to be smaller or larger than other normalized torque pattern switching, it is possible to more reliably switch from one normalized torque pattern to another pattern and vice versa. You can prevent the current from vibrating by going back and forth between other normalized torque patterns. .

  Furthermore, the torque control unit can adjust the compensation torque pattern by multiplying the compensation torque pattern by a predetermined modulation rate, thereby increasing or decreasing the compensation torque pattern over the entire rotation angle of the motor. Become.

  Further, the torque control unit increases / decreases the normalized torque pattern only in a partial section of the rotation angle of the motor, and adjusts the compensation torque pattern, for example, so that the output torque of the motor reaches a peak. By increasing / decreasing the normalized torque pattern in a part of the angle, the torque generated by the motor can be adjusted according to various ways of the torque.

  Here, the torque control unit performs increase / decrease of the normalized torque pattern as described above so that the range of the rotation speed of the motor becomes small, or selects an optimum normalized torque pattern, and supplies current to the motor. By correcting the value, the motor output torque can be matched with the load torque even in the overload region where the pressure ratio is larger, and the electric compressor can be operated under a wide range of pressure conditions.

  According to the present invention, by changing the torque of the motor following the load torque of the compressor using a pre-stored normalized torque pattern, the rotation fluctuation of the compressor based on the fluctuation of the load torque, that is, Rotational vibration generated due to an imbalance between the driving torque and load torque of the compressor can be reliably suppressed at low cost.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  First, the outline of the present invention will be described with reference to FIGS. First, FIG. 15A is a diagram showing the operating range 40 of the compressor that performs the respective steps of suction, compression, and discharge during one rotation as described above, and FIG. A diagram showing an example of a load torque in the vicinity of numbered (1) and an example of a normalized torque pattern used in the present invention, (C) is a load torque in the vicinity of (2) similarly numbered with 42, It is the figure which showed an example of the normalization torque pattern used by this invention. In FIG. 15A, the horizontal axis is the low pressure (Lp, unit: MPa) of the compressor, the vertical axis is the high pressure (Hp, unit: MPa), and (B) and (C) are the rotors in the motor. And the vertical axis represents torque (unit: Nm).

  The number 40 in FIG. 15A is an example of a design range of a high pressure during compression and a low pressure during suction in a compressor that performs each process of suction, compression, and discharge during one rotation. If the pressure is high outside this range 40, the compressor may be broken. If the pressure is low, the compression ratio is too high, and there is a risk that some part is excessively stressed.

  In FIG. 15A, the magnitude of the load torque in each of the suction, compression, and discharge strokes in the vicinity of (1) numbered 41 and the vicinity of (2) numbered 42. For example, in the vicinity of (1) numbered 41, the difference between the suction side and the compression side is small like the curve numbered 43 in the graph of (B), and numbered 42 ( In the vicinity of 2), the difference between the suction side and the compression side is large. This difference varies depending on, for example, the temperature condition of the outside air, the difference in heating and cooling, the rotational speed of the compressor, the difference in operation method, and the like.

  As described above, in the compressor, the drive motor connected to the compressor is operated so as to have a constant rotational speed during one rotation, and each process of suction, compression, and discharge that occurs during this one rotation. Due to the change in the refrigerant gas pressure at, a rotational speed fluctuation caused by an imbalance between the driving torque and the load torque is generated, thereby generating vibration. Therefore, in order to prevent the vibration, the vibration is surely prevented unless the difference in the magnitude of the load torque between the suction side and the compression side as shown in FIGS. 15B and 15C is taken into consideration. Can not do it. Therefore, in the present invention, a normalized torque pattern such as numbered 44 and 46 in FIGS. 15B and 15C is selected in correspondence with the magnitude of the load torque, and the driving torque of the motor is selected from the compressor. The vibration is prevented by balancing with the load torque generated by the driving.

  The normalized torque patterns 44 and 46 are coefficients for changing the output torque of the motor so as to match the estimated fluctuation torque of the load calculated in advance for every 30 degrees of rotation angle of the rotor of the motor, for example. In this manner, the rotation angle is divided into a plurality of 30 degrees and a pattern representing the relationship with the compensation torque coefficient in each division. By defining the normalized torque patterns 44 and 46 in this way, the normalized torque is set to the average torque for rotating the motor (for example, 38 in FIG. 15B and 39 in FIG. 15C). When the compensation torque pattern is generated by multiplying the pattern, a compensation torque pattern is generated in which the normalized torque pattern is greatly adjusted under conditions where the compressor load is large, and normalization is performed accordingly under conditions where the compressor load is small. A compensation torque pattern in which the torque pattern is adjusted to be small is generated.

In the present invention, as shown in FIGS. 1 and 2 , the motor is driven with the compensation torque pattern generated in this way ,
A motor control device that is connected to a compressor and controls the rotational speed of the motor 2 by an AC power source 3 and an inverter 4,
A speed control unit 20 for setting a current command value to be supplied to the motor 2 via the inverter 4 in order to rotate the motor 2 at a target rotational speed;
A current sensor 10 for detecting an actual current value supplied to the motor;
A rotational position estimation unit 11 having a rotational speed calculation function corresponding to the rotational position of the motor 2 from the actual current value, while estimating the rotational position of the motor 2 from the actual current value;
Average torque calculation for calculating the average load torque of the motor 2 from the difference between the rotational speed command value and the actual motor rotational speed obtained via the rotational position estimating unit from the actual current value detected by the current sensor. Part 12;
Torque pattern storage unit 13 that stores a normalized torque pattern that serves as a reference for varying the output torque of the motor according to the rotational position of the motor (select from the normal pattern selection unit 27 when there are multiple normalized torque patterns) And)
Torque for correcting a current value supplied to the motor by generating a compensation torque pattern for varying the output torque of the motor according to the rotational position of the motor by the product of the average load torque and the normalized torque pattern And a control unit 13.
In such a configuration,
First, due to the difference between the actual motor rotation speed calculated by the speed / position estimation unit 11 from the actual current value detected by the current sensor in the rotating motor and the rotation speed command value , FIG. The average load torque as indicated by 38 and 39 in C) is calculated. Then, a normalized torque pattern corresponding to the rotation state at that time is selected from the normalized torque patterns indicated by 44 and 46 in FIGS. 15B and 15C, and the normalized torque pattern and the average load torque are selected. Is used to generate a compensation torque pattern, and the current applied to the motor is controlled by the compensation torque pattern, so that driving corresponding to the compressor load state can be performed.

  By doing so, the current value supplied to the motor can be easily corrected, and smooth control is possible. The current supplied to the motor can be easily obtained from the relational expression between torque and current, and the torque pattern can be set with the output torque value as it is by performing motor control with a current command. Therefore, it is not necessary to calculate the voltage value by simulation or the like, and development is easy.

  In the following description, the case where the coefficient of the normalized torque pattern is given every 30 degrees will be described as an example, and the case where the normalized torque pattern is one and two will be described as an example. Obviously, this is not limited to 30 degrees, and the number of normalized torque patterns may be three or more.

  Of the normalized torque patterns indicated by 44 and 46 in FIGS. 15B and 15C, various methods are conceivable for selecting a normalized torque pattern corresponding to the rotation state at that time. FIG. 9 is a diagram for explaining the first method. 9, (A) shows the operating range 40 of the compressor, the position 51 of the load torque 53 shown in (C), and the position 52 of the load torque 54 shown in (B), as in FIG. (B) is a diagram showing a load torque 54 and an average torque 56 corresponding to 52, and (C) is a diagram showing a load torque 53 and an average torque 55 corresponding to 51. In FIG. 9A, the horizontal axis is the low pressure (Lp, unit: MPa) of the compressor, the vertical axis is the high pressure (Hp, unit: MPa), and (B) and (C) are the horizontal axes of the rotor in the motor. The rotation angle and the vertical axis are torque (unit: Nm).

  In the first method of selecting the normalized torque pattern shown in FIG. 9, it is determined whether the average load torques 55 and 56 for driving the motor are larger or smaller than a certain torque reference value 37, thereby (B), In (C), it is determined which of the load torques indicated by 53 and 54 should be used. That is, when the load torques indicated by 53 and 54 in (B) and (C) are averaged, a line indicated by 56 in (B) and 55 in (C) is obtained. By looking at whether the load torque is large or small, it can be understood which of the load torques (B) and (C) should be adopted, and the compensation torque is thereby created.

  The control flow for implementing the first method is shown in FIG. 10. In the figure, reference numeral 12 denotes PI control (proportional integral differential) for calculating the average torque, and reference numeral 14 denotes the rotational speed command and the actual Subtraction to obtain the difference from the rotational speed, 57 is the average of the load torque, 58 is a load judgment value consisting of the load torque averaged at 57, with the reference value as shown by 37 in FIG. Comparison 59 is a determination of which one to select when the torque patterns indicated by 53 and 54 in FIG.

  First, the difference between the rotational speed command input to the subtraction 14 and the actual rotational speed calculated from the current value flowing through the motor and the like is obtained, and the average torque is calculated by the PI control 12. Then, the plurality of calculated average torques are further averaged by averaging 57 to obtain a load determination value. Then, the obtained value is 58 and compared with a threshold value composed of a reference value as indicated by 37 in FIG. 9. When the average value is smaller than this threshold value, for example, when the torque pattern A in FIG. The torque pattern A ′ in FIG. 9B is selected at 59, and the compensation torque is calculated as described above.

  The second method of selecting the normalized torque pattern is a method using the fluctuation range of the rotational speed as shown in FIG. In FIG. 11A, the horizontal axis represents the rotation angle of the rotor in the motor, the vertical axis represents the number of rotations, and in (B), Lp represents the low pressure side (unit: Mpa), and Hp represents the high pressure. Pressure (unit: Mpa), the vertical axis is the fluctuation range of the rotation speed, and the rotation speed is large where the difference between high pressure and low pressure is large as shown in the solid graph of FIG. As shown in FIG. 11A, the amplitude becomes smaller depending on the load state.

  That is, the vibration is large where the difference between the high pressure and the low pressure is large, and the vibration is small where the difference is small. Therefore, the vibration state of the compressor can be estimated by looking at the amplitude of the rotational speed indicated by 60 in FIG. 11 (A), which corresponds to either load torque shown in FIGS. 15 (B) and 15 (C). Since it can be understood that the normalized torque pattern should be adopted, the compensation torque is created with the selected normalized torque pattern.

  FIG. 12 is a diagram for explaining a third method of selecting a normalized torque pattern. In FIG. 12, (A) is the compressor operating range 40 as in the case of FIG. 15, and in the operating range 40 at the position 66 where the motor current flows as shown in FIG. FIG. 12C shows a position 65 where the motor current flows as shown in FIG. 12C, FIG. 12B shows a motor current corresponding to the position indicated by 66 in FIG. FIG. 6 is a diagram showing a motor current corresponding to the position indicated by 65. In FIG. 12 (A), the horizontal axis is the low pressure (Lp, unit: MPa) of the compressor, the vertical axis is the high pressure (Hp, unit: MPa), and (B) and (C) are the horizontal axes of the rotor in the motor. A rotation angle and a vertical axis | shaft are an electric current (unit: A).

  In the third method, the load state is determined by calculating whether the peak current amount of the motor current is an overload region that is larger than a reference value or a normal region that is smaller than the reference value, and has been described with reference to FIG. ) And (C) to determine which normalized torque pattern is selected. In other words, the motor connected to the compressor is generally controlled so that the rotational speed is constant, but even if the load on the motor fluctuates, the rotational speed remains constant, so the current applied to the motor When the load is increased, the peak value is increased as shown in FIG. 12 (B), and when the load is reduced, the peak value is controlled as shown in FIG. 12 (C). . Therefore, the load state can be known by looking at the motor current value, and it can be determined whether the normalized torque pattern shown in (B) or (C) described in FIG. 15 should be selected.

  In the example shown here, only the peak value of the current, that is, the current value corresponding to the load on the high voltage side in the compressor has been described, but in this case, for example, the compressor is galling for some reason and the motor Since the same control is performed even when the current increases, for example, such a noise may be eliminated by simultaneously viewing the bottom peak value on the low voltage side.

  FIG. 13 is a diagram for explaining a fourth method for selecting a normalized torque pattern. In FIG. 13, (A) shows the operating range 40 of the compressor as in the case of FIG. 15, and the position 71 when the compression ratio in the compressor as shown in FIG. The figure which showed the position 72 in case the compression ratio in a compressor as shown in FIG.13 (C) in the operating range 40 is large, (B) is in the compressor corresponding to the position shown by 71 in (A). The figure which showed the peak position of the motor rotational speed when a compression ratio is small, (C) shows the peak position of the motor rotational speed when the compression ratio in the compressor corresponding to the position shown to 72 in (A) is large. It is a figure. In FIG. 13A, the horizontal axis is the low pressure (Lp, unit: MPa) of the compressor, the vertical axis is the high pressure (Hp, unit: MPa), and the graphs in (B) and (C) are for the motor. The rotation angle of the rotor, on the upper and lower graphs, the vertical axis represents the load, and in the lower graph, the vertical axis represents the rotational speed.

  In the fourth method, the periodic load torque fluctuation with respect to the rotation angle of the rotor in the motor differs depending on the load state in the compressor, and the number of rotations of the motor is accelerated / decelerated in accordance with the load torque fluctuation. The load state is determined by calculating whether the rotor angle at which the rotation speed of the motor reaches a peak is larger or smaller than a certain reference value, and as a result, either (B) or (C) described in FIG. It is determined whether the normalized torque pattern should be selected.

  That is, the fluctuation of the load torque during one rotation in the compressor has a characteristic with respect to the angle of the rotor of the motor, and the rotation speed of the motor is accelerated and decelerated by the fluctuation of the load. That is, in the case of the upper graph in FIG. 13B where the compression ratio in the compressor is small, the peak value of the load torque appears when the rotor angle is small (to the left in the figure), and is large in FIG. 13C. In such a case, the peak value of the load torque is when the rotor angle is large (rightward in the figure). Accordingly, as shown in the lower graphs of FIGS. 13B and 13C, when the rotor rotation speed peak is (B), the rotor angle is small, and in the case of (C) Appears when the rotor angle is large.

  For this reason, in the fourth method, it is detected that the peak of the rotational speed of the motor changes, and whether it is larger or smaller than the reference angle, either (B) or (C) described in FIG. It is determined whether or not the indicated normalized torque pattern should be selected. By doing this, the pressure in the compressor is high and low, that is, the pattern according to the shape of the load torque can be seen, and the normalized torque pattern that matches the load pattern can be selected directly, so the direct value is Obtained and highly accurate selection can be made.

  In this way, it is determined which of the normalized torque patterns 44 and 46 shown in FIGS. 15B and 15C is used. The normalized torque pattern 44 is changed to, for example, 46 patterns. In switching, if this switching is performed when the load is large, the current value changes greatly. As shown in the left diagram of FIG. 14D, from the normalized torque pattern 46 (2). As a result of switching to 44 (1), vibration due to overshoot as indicated by 86 occurs.

  FIGS. 14A, 14B, and 14C show a method for preventing this. First, FIG. 14A shows the first method, in which the horizontal axis represents the rotation angle of the rotor in the motor and the vertical axis represents the load torque. For example, the normalized torque pattern 44 shown in FIG. When the pattern of A with the number A and the normalized torque pattern 46 shown in (C) with the pattern A ′ with the number 82, the torque difference in each torque pattern is increased at a constant rate, or The compensation torque pattern is generated while decreasing.

That is, the normalized torque patterns 81 (A) and 82 (A ′) shown in FIG. 14A are stored as compensation torque coefficients for each rotation angle of the rotor of the motor as an example, as described above. Therefore, when switching between 81 (A) and 82 (A ′), the value of 81 (A) is not directly switched to the value of 82 (A ′), but both values are read every 30 degrees. , for example, 1/10 of the difference between generating a small Toe while the compensation torque pattern reduced for each round, and finally to the desired value. As a result, shocks such as transient speed fluctuations and current oscillations that occur when the normalized torque pattern 81 (A) is changed to 82 (A ′) or vice versa can be further reduced.

  FIG. 14B is a diagram for explaining a second method of switching the normalized torque pattern, in which the horizontal axis represents the rotation angle of the rotor in the motor, and the vertical axis represents the load torque. In FIG. It is the figure which showed the load torque 83 and the normalized torque pattern 84 which correspond. In the second method, switching from the normalized torque patterns 44 to 46 shown in FIGS. 15B and 15C or vice versa is performed at an angle where the load torque in the normalized torque patterns 44 and 46 is small. That is, it is performed at the position indicated by 85 in FIG.

  That is, the above-described method is used to determine which of the normalized torque patterns 44 and 46 shown in FIGS. 15B and 15C is used, and when a switching instruction is received, the instruction is received. Instead of switching immediately after that, as shown in 85 of FIG. 14B, the rotation angle of the motor at which the load torque becomes small is examined, and switching is performed at that angle. In this way, the current to the motor is small at an angle where the load torque is small, and therefore vibration due to it is less likely to occur, so that shocks such as transient speed fluctuations and current vibration can be reduced.

  FIG. 14C is a diagram for explaining a third method of switching the normalized torque pattern, and when selecting the normalized torque pattern corresponding to the rotation state of the motor described in FIGS. When the load torque applied to the motor is a value in the vicinity of the threshold value in each normalized torque pattern selection, for example, the normalized torque pattern of A with the number 81 described in FIG. This is to prevent the current from oscillating by going back and forth and selecting the pattern A ′.

  That is, in the case of FIG. 14C, when switching from the normalized torque pattern A to A ′, and conversely from A ′ to A, there are two threshold values for determining switching, for example, from the normalized torque pattern A When switching to A ′, switching is performed with a threshold value n closer to A ′, and conversely, when switching from the normalized torque pattern A ′ to A, switching is performed with a threshold value m closer to A. In this way, even when switching from the normalized torque pattern A to A ′, or conversely from A ′ to A, switching is performed more reliably in the state of the normalized torque pattern A or A ′. It is possible to prevent the current from oscillating by going back and forth between the normalized torque patterns A or A ′ and fluttering.

  The above is the outline of the motor control device connected to the compressor according to the present invention. Next, an embodiment of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a block diagram of a motor torque control apparatus 1A applicable to drive the compressor of the present invention.

The motor 2 in this embodiment is controlled by an AC power source 3 and an inverter 4. The torque control device 1A according to the present embodiment includes a current sensor 10 that detects a current value supplied to the motor 2, and a speed / position estimation unit that estimates a motor rotation position (rotation angle) of the motor 2 from the detected current value. ( Hereinafter referred to as a position estimation unit ) 11, a speed PI control unit (average torque calculation unit, PI control unit is proportional, integral, differential control: Proportional Integral Differential) 12 for calculating the average load torque of the motor, and FIG. A load torque compensator (torque control unit, torque pattern storage unit ) 13 for storing a predetermined normalized torque pattern described above and correcting a current supplied to the motor 2 according to the load state of the motor 2; , for rotating the motor 2 at the target rotation speed (rotation speed command value), the speed system for commanding the electric current supplied to the motor 2 Comprises a section 20, the.
That is, the speed control unit 20 converts the rotational speed command value for rotating the motor 2 at the target rotational speed into a current command value for controlling the rotational speed of the motor via the current conversion unit 16, the subtraction unit 17, and the current PI control unit 18. And supplied to the inverter 4.

The speed PI control unit 12 calculates the average of the load torque of the motor 2 that varies according to the rotation from the deviation (obtained by the subtraction unit 14) between the rotation speed command and the motor position estimated by the speed / position estimation unit 11. It is a proportional integral element that calculates the average torque that is a value.
That is, as shown in FIG. 1, the actual motor calculated by the speed / position estimation unit 11 from the rotation speed command value input to the subtraction unit 14 and the current value actually supplied to the motor by the current sensor 10. The rotation number is input to the subtraction unit 14, and the difference between the rotation number command value and the actual rotation number is obtained by the subtraction unit 14. Based on the rotational speed difference, the speed PI control unit 12 calculates the average load torque.

  The load torque compensator 13 stores a normalized torque pattern as described with reference to FIG. As described above, this normalized torque pattern is a coefficient for changing the output torque of the motor 2 for each rotational position of the motor 2, and the rotation angle of the motor 2 is divided into a plurality of parts, and the compensation torque in each of the divisions. It is a pattern showing the relationship with a coefficient. The load torque compensator 13 calculates an average torque × normalized torque pattern and generates a compensation torque pattern. That is, under a condition where the compressor load is large, the normalized torque pattern is adjusted to be large and a compensation torque pattern is generated. Under a condition where the compressor load is small, the normalized torque pattern is adjusted to be small and the compensation torque pattern is adjusted accordingly. A pattern is generated.

Further, the average torque and the compensation torque pattern are added by the adding unit 15 to obtain a motor output torque. This motor output torque indicates the relationship between the rotation angle of the motor 2 and the command value of the current supplied to the motor 2 (referred to as command current as appropriate). Further, this current is converted by the current converter 16 to obtain a d-axis command current i _d ^* and a q-axis command current i _q ^* . Deviations between these commands and the motor current are calculated by the subtracting unit 17, and command voltages v _d and v _q are further calculated by the current PI control unit 18 and given to the inverter 4 according to the rotation angle of the motor 2. Here, the speed PI control unit 12, the addition unit 15, the current conversion unit 16, the subtraction unit 17, and the current PI control unit 18 constitute a speed control unit 20.

  Thus, in the torque control device 1A of the present embodiment, torque control according to the compressor load is possible by sine wave (180 ° energization) vector control, and compared with intermittent drive waveforms (120 ° energization, etc.) Smooth control becomes possible. Further, since the control for the inverter 4 is a current command, the normalized torque pattern can be set as it is in the torque control device 1A as it is. Therefore, it is not necessary to calculate the voltage value by simulation or the like, and development is easy. Further, by using the normalized torque pattern for the load torque compensator 13, torque control can be performed with a simple control method.

  Furthermore, according to the torque control device 1A of the present embodiment, the torque of the motor is changed to follow the load torque of the compressor by using a pre-stored normalized torque pattern, thereby being based on the fluctuation of the load torque. It is possible to suppress the rotational fluctuation of the compressor, that is, the rotational vibration generated due to the imbalance between the driving torque and the load torque of the compressor at a low cost.

  Next, a second embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to the said 1st Embodiment, the same code | symbol is used and the description is abbreviate | omitted.

  In the torque control device 1B of the present embodiment shown in FIG. 2, the load torque compensator 13 uses a normalized torque pattern of compensation torque (average torque × normalized torque pacoon), for example, FIG. Two or more are stored as shown in (C). The torque control device 1B includes a normalization pattern selection unit 27 that selects an appropriate pattern from these normalized torque patterns.

  The normalization pattern selection unit 27 appropriately selects an optimum one from the plurality of normalization patterns so that the estimated rotational speed fluctuation range calculated from the motor current is a predetermined value or less. Also at this time, the selection of the normalization pattern in the normalization pattern selection unit 27 is performed by repeatedly detecting the motor current during the rotation of the motor 2 and setting a specific normalization pattern from a plurality of results. This is executed by so-called feedback control, which is performed by selecting a normalization pattern so that the estimated rotational speed fluctuation range is equal to or less than a predetermined value while determining whether or not has increased or decreased. As a result, even in an overload region where the pressure ratio is larger, the motor output torque can be matched with the load torque, and operation is possible under a wide range of pressure conditions.

  Next, a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is used about the structure similar to the said 1st Embodiment, and the description is abbreviate | omitted. The third embodiment of the present invention shown in FIG. 3 corresponds to the first method of FIG. 9 described in the outline of the present invention. In the first method shown in FIG. 9, as described above, it is determined whether the average load torques 55 and 56 for driving the motor are larger or smaller than a certain reference value 37 of torque, and thereby FIG. , (C), which of the load torques indicated by 53 and 54 is to be used is determined.

  The normalization pattern selection unit 27 in the torque control device 1C of the present embodiment shown in FIG. 3 is based on the rotation speed command and the motor rotation speed estimated by the speed / position estimation section (position estimation section) 11 from the motor current. The speed difference calculated by the subtracting unit 14 is received by the speed PI control unit (average torque calculating unit) 12 and the average value is calculated from the plurality of calculated average torques as described above with reference to FIG.

  This average value is the average load torque indicated by 55 and 56 in FIGS. 9B and 9C, and this is the reference value (threshold value) 37 indicated by 37 in FIGS. 9B and 9C. 9B, it is determined which of the torque patterns indicated by 53 and 54 in FIGS. 9B and 9C, whereby 44 in FIGS. 15B and 15C, Which of the normalized torque patterns indicated by 46 is used is selected.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is used about the structure similar to the said 1st Embodiment, and the description is abbreviate | omitted. The fourth embodiment of the present invention shown in FIG. 4 corresponds to the second method of FIG. 11 described in the outline of the present invention. In the second method shown in FIG. 11, selection is performed using the fluctuation range of the rotation speed as described above. As shown in the solid graph of FIG. When the difference in low pressure is large, the rotational speed is large, and when the difference is small, the rotational speed is also small. As indicated by 60 in FIG. Therefore, in the fourth embodiment, the vibration state of the compressor is estimated by looking at the amplitude of the rotational speed, and thereby the normalized torque corresponding to either load torque shown in FIGS. 15B and 15C. It is determined whether the pattern should be adopted.

  The normalization pattern selection unit 27 in the torque control device 1D of the present embodiment shown in FIG. 4 receives the motor rotation speed ωes estimated by the speed / position estimation unit (position estimation unit) 11 from the motor current, and FIG. As shown by 60 in (A), the vibration state of the compressor is estimated by calculating its amplitude from the number of rotations of the rotor 2 in the motor 2 for each rotation angle θes, whereby (B) and (B) in FIG. It is determined which normalized torque pattern corresponding to which load torque shown in C) should be adopted.

  FIG. 5 is a block diagram of the fifth embodiment of the present invention. The same reference numerals are used for the same components as in the first embodiment, and the description thereof is omitted. The fifth embodiment of the present invention shown in FIG. 5 corresponds to the third method of FIG. 12 described in the outline of the present invention, and in an overload region where the peak current amount of the motor current is larger than a certain reference value. A load state is determined by calculating whether there is a small normal region, and it is determined whether to select the normalized torque pattern shown in (B) or (C) described in FIG. It is.

  As described above, the motor connected to the compressor is controlled so that the rotation speed is constant. However, even if the load on the motor fluctuates, the rotation speed remains constant, so the current applied to the motor When the load is increased, the peak value is increased as shown in FIG. 12B, and when the load is reduced, the peak value is controlled as shown in FIG. 12C. . Therefore, it is possible to determine the load state by looking at the motor current value, and thereby determine which of the normalized torque patterns shown in (B) and (C) described in FIG. 15 should be selected. It is.

  Therefore, the normalization pattern selection unit 27 in the torque control device 1E of the present embodiment shown in FIG. 5 determines whether it corresponds to (B) or (C) in FIG. Thus, it is determined whether the normalized torque pattern shown in (B) or (C) described in FIG. 15 should be selected.

  In addition, as described in the war, in the example shown here, it has been described that only the peak value of the current, that is, the current value corresponding to the load on the high pressure side in the compressor is viewed, but in this case, for example, the compressor is Since the same control is performed even when the motor current increases due to such a situation, for example, the bottom peak value on the low-pressure side may be viewed simultaneously to eliminate such noise.

  FIG. 6 is a block diagram of the sixth embodiment of the present invention. The same reference numerals are used for the same components as in the first embodiment, and the description thereof is omitted. The sixth embodiment of the present invention shown in FIG. 6 corresponds to the fourth method of FIG. 13 described in the outline of the present invention, and the periodic load torque fluctuation with respect to the rotation angle of the rotor in the motor is a compressor. Calculates whether the rotor angle at which the motor speed reaches a peak is larger or smaller than a certain reference value, using the fact that the speed of the motor varies depending on the load state in the motor. Is used to determine the load state, thereby determining which of the normalized torque patterns shown in FIGS. 15B and 15C described above should be selected.

  For this reason, the normalization pattern selection unit 27 in the torque control device 1F of the present embodiment shown in FIG. 6 calculates the rotation angle θes and the rotation speed (rotation speed) of the rotor of the motor 2 calculated by the speed / position estimation unit (position estimation unit) 11. In response to the rotational speed (ωes), the rotor rotational angle θes at which the rotational speed (rotational speed) ωes peaks is calculated. Then, from the calculation result, it is determined whether the peak is shown in either (B) or (C) in FIG. 13, and thereby the normality shown in either (B) or (C) described in FIG. To select the torque torque pattern

  In this way, it is determined which of the normalized torque patterns 44 and 46 shown in FIGS. 15B and 15C is used. As described above, as shown in FIG. When switching from the normalized torque pattern 44 shown in (C) to, for example, 46, vibration due to overshoot accompanying switching shown in 86 in FIG. Therefore, control for preventing this vibration will be described.

The first method of control, the compensation torque patterns torque difference in the pattern of assigned thereto A '81 patterns and 82 number of A which are numbered, while Toe decline at a constant rate as shown in FIG. 14 This is because when the normalization pattern selection unit 27 instructs switching of the normalization torque pattern, the load torque compensation unit (torque control unit torque pattern storage unit) 13 and the pattern 81 of A calculating a torque difference in the pattern 82 of a ', for example, every 30 degrees compensation silk factor is provided, a tenth of the difference between small Toe while generating the compensation torque pattern reduced for each lap Therefore, the motor output torque is given to the adder 15. By doing so, it is possible to further reduce shocks such as transient speed fluctuations and current oscillations that occur when the normalized torque pattern 81 (A) is changed to 82 (A ′) or vice versa. .

  Also, the second method of pattern switching is to switch the normalized torque patterns 44 to 46 shown in FIGS. 15 (B) and 15 (C) or vice versa to the load in the normalized torque patterns 44 and 46. The torque is performed at a small angle.

  Therefore, the normalization pattern selection unit 27 receives the rotation angle θes and the rotation speed (number of rotations) ωes of the rotor of the motor 2 from the speed PI control unit (average torque calculation unit) 12, and further receives a load torque compensation unit (torque control). The angle at which the load torque is small is calculated from the compensation torque in the (part torque torque storage unit) 13 and switching is performed at that angle. By doing so, the current to the motor is small at an angle where the load torque is small, and therefore vibration due to the motor is less likely to occur, and shocks such as transient speed fluctuations and current vibration can be reduced.

  In addition, the third method shown in FIG. 14C is used to determine whether or not to switch from the normalized torque pattern A to A ′ shown in FIG. 14C and vice versa. For example, when switching from the normalized torque pattern A to A ′, the threshold value n is closer to A ′, and conversely, when switching from the normalized torque pattern A ′ to A, it is more A. Switching is performed at a close threshold value m.

  In the third method, in each of the embodiments 3 to 6 shown in FIGS. 3 to 6, the normalized torque pattern A shown in FIG. Each of the normalized pattern selection units 27 has two threshold values for determination in switching from 'to A. For example, in switching from the normalized torque pattern A to A', switching is performed with a threshold value n closer to A '. Conversely, switching from the normalized torque pattern A ′ to A is performed by switching at a threshold value m closer to A. In this way, even when switching from the normalized torque pattern A to A ′, or conversely from A ′ to A, switching is performed more reliably in the state of the normalized torque pattern A or A ′. It is possible to prevent the current from oscillating by going back and forth between the normalized torque patterns A or A ′ and fluttering.

  Next, a tenth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is used about the structure similar to the said 1st Embodiment, and the description is abbreviate | omitted. In the tenth embodiment shown in FIG. 7, in addition to the configuration in the torque control devices 1A and 1B of the first and second embodiments, the compensation torque for adjusting the compensation torque pattern by multiplying the compensation torque by the modulation factor Kn. An adjustment unit 25 is further included.

  The compensation torque adjustment unit 25 is provided with the estimated position of the motor from the speed / position estimation unit 11, and the estimated rotation speed fluctuation range of the motor calculated from the motor current (the maximum rotation number during one rotation of the motor 2) An appropriate modulation rate Kn is selected from among a plurality of preset modulation rates Kn so that the difference in the minimum rotation speed is not more than a predetermined value. The selection of the modulation rate Kn in the compensation torque adjustment unit 25 is performed by repeatedly detecting the motor current during the rotation of the motor 2 and setting the modulation rate Kn to determine whether the estimated rotation speed fluctuation range has increased or decreased. However, it is executed by so-called feedback control that is performed by increasing or decreasing the modulation rate Kn set in a plurality of stages so that the estimated rotational speed fluctuation range is equal to or less than a predetermined value.

  In this case, in the load torque compensator 13, the compensation torque pattern is calculated by average torque × normalized torque pacoon × modulation factor Kn. With the modulation factor Kn, the compensation torque coefficient can be increased or decreased in the entire compensation torque pacoon (the entire rotation angle of the motor 2), so that the applicability of torque control can be easily adjusted.

  Further, the modulation factor Kn can be set to zero. For example, when Kn = O, there is no torque control, and when Kn = 1.0, torque control is performed with a normalized torque pattern as designed. Thus, for example, torque control is performed in a low rotation range where vibration is likely to occur, torque control is not performed in a high rotation range, and torque control is gradually weakened in an intermediate rotation range (modulation rate Kn is decreased). Control). In the overload region where the pressure ratio is large, the motor output torque and the load torque can be matched by increasing the modulation factor Kn to 1.0 or more. In this way, it is possible to operate using torque control effectively under a wide range of pressure conditions.

  Next, an eleventh embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is used about the structure similar to the said 1st Embodiment, and the description is abbreviate | omitted. In the torque control device 1H according to the eleventh embodiment shown in FIG. 3, among the normalized torque pacoons stored in the load torque compensator 13 used for calculating the compensation torque (average torque × normalized torque pacoon), A normalization pattern adjustment unit 26 that increases or decreases the compensation torque coefficient only in a part of the rotation angle of the motor 2 is provided.

  The normalization pattern adjustment unit 26 increases or decreases the compensation torque coefficient, for example, in a section where the maximum value and the minimum value of the rotation speed are matched so that the estimated rotation speed fluctuation range calculated from the motor current is equal to or less than a predetermined value. Thereby, the torque peak can be increased or decreased. As a result, even in an overload region where the pressure ratio is larger, the motor output torque and the load torque can be matched, and the operation can be performed so as to suppress the vibration or to exhibit a larger torque.

  It should be noted that the adjustment or selection of the normalized torque pattern in the tenth and eleventh embodiments can be performed sequentially corresponding to pressure fluctuations and the like. In addition, the torque pattern is adjusted or selected so that the rotational speed fluctuation range is a predetermined value or less, but may be adjusted or selected so that the rotational speed fluctuation range is minimized. Thereby, the maximum vibration reduction effect can be obtained. In addition, by setting the rotational speed fluctuation range to a certain value or less, the current can be increased only by the required amount of vibration reduction, thereby increasing the efficiency.

  Furthermore, the above embodiments may be combined. For example, the compensation torque adjustment unit 25 and the normalization pattern selection unit 27 may be combined, and the modulation factor Kn may be further multiplied after the normalization torque pattern is selected. Alternatively, the compensation torque adjustment unit 25 and the normalization pattern adjustment unit 26 may be combined, and the modulation rate Kn may be applied to only a part of the torque pattern. In addition, the normalization pattern adjustment unit 26 and the normalization pattern selection unit 27 may be combined so that only a portion having the normalization torque pattern can be increased or decreased and the pattern can be changed. Furthermore, the compensation torque adjustment unit 25, the normalization pattern adjustment unit 26, and the normalization pattern selection unit 27 may all be combined.

  Moreover, although an example of the current detection method was shown in FIGS. 1 to 8, the method is not limited, such as using a Hall sensor, a CT (current transformer), a shunt resistor, etc. The detection may be performed not only by directly detecting the current value but also by estimating the current value with a low-cost one shunt resistor, for example. The number of detected currents may be two-current detection, one-current detection, or the like.

  In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

  According to the present invention, it is possible to control a motor connected to a compressor with a simple and inexpensive configuration without causing vibration and the like, and it is possible to provide a motor control device suitable for air conditioning.

It is a block diagram of the control apparatus of a moke connected to the air-conditioning rotary compressor in this Embodiment. It is the block diagram shown about 2nd Embodiment of the torque control apparatus. It is the block diagram shown about 3rd Embodiment of the torque control apparatus. It is the block diagram shown about 4th Embodiment of the torque control apparatus. It is the block diagram shown about 5th Embodiment of the torque control apparatus. It is the block diagram shown about 6th Embodiment of the torque control apparatus. It is the block diagram shown about 7th Embodiment of the torque control apparatus. It is the block diagram shown about 8th Embodiment of the torque control apparatus. It is a figure for demonstrating 2nd Embodiment of a torque control apparatus, (A) is the operating range 40 of a compressor, the position 51 of the load torque 53 shown to (C), and the load torque 54 shown to (B). (B) is a diagram showing a load torque 54 and an average torque 56 corresponding to 52, and (C) is a diagram showing a load torque 53 and an average torque 55 corresponding to 51. It is a figure showing the flow which implements 2nd Embodiment of a torque control apparatus. It is a figure for demonstrating 3rd Embodiment of a torque control apparatus, (A) is a graph with which the vertical axis | shaft with respect to the rotation angle of the rotor of a motor showed the rotation speed, (B) is a fluctuation range of compression pressure and rotation speed, and 3 is a three-dimensional graph showing the relationship. It is a figure for demonstrating 4th Embodiment of a torque control apparatus, (A) is the driving | operation range 40 of a compressor, the position 66 where a motor current flows as shown to (B), and as shown to (C). (B) shows the motor current corresponding to the position indicated by 66 in (A), and (C) corresponds to the position indicated by 65 in (A). It is the figure which showed the motor current which carried out. It is a figure for demonstrating 5th Embodiment of a torque control apparatus, (A) is the figure which showed the operation range 40 of the compressor, the position 71 when the compression ratio in a compressor is small, and the position 72 when large, (B) is a diagram showing the peak position of the motor speed when the compression ratio in the compressor corresponding to the position indicated by 71 in (A) is small, and (C) is the position indicated by 72 in (A). It is the figure which showed the peak position of the motor rotation speed when the compression ratio in the corresponding compressor is large. FIG. 6 is a diagram for explaining torque control devices according to sixth and seventh embodiments. When switching from one normalized torque pattern to another normalized torque pattern or when performing reverse switching, a rapid speed change or current It is a figure for demonstrating the method of preventing the vibration by a change, and going back and forth between one normalization torque pattern and another normalization torque pattern. (A) is a diagram showing the operating range on the high pressure side (Hp) and the low pressure side (Lp) in a compressor that performs each stroke of suction, compression, and discharge during one rotation, and (B) is a diagram of (A). The figure which showed an example of the load average torque in the position of (1), and the normalized torque pattern of this invention, (C) is the load average torque in the position of (2) of (A), and the normalized torque pattern of this invention. It is the figure which showed an example.

Explanation of symbols

1A to 1H Torque control device 2 Motor 3 AC power supply 4 Inverter 10 Current sensor 11 Speed / position estimation unit (position estimation unit)
12 Speed PI controller (average torque calculator)
13 Load torque compensator (torque controller torque pacoon storage unit)
14 subtraction unit 15 addition unit 16 current conversion unit 17 subtraction unit 18 current PI control unit 20 speed control unit 25 compensation torque adjustment unit 26 normalization pattern adjustment unit 27 normalization pattern selection unit

Claims (12)

A motor control device that is connected to a compressor and controls the rotational speed of the motor by an AC power source and an inverter ,
A speed control unit for setting a current command value to be supplied to the motor via the inverter in order to rotate the motor at a target rotational speed;
A current sensor for detecting an actual current value supplied to the motor;
With estimates the rotational position of the motor from the actual current value, and the rotational position estimation unit having the actual rotation speed calculation function corresponding to the rotational position of the motor from the current value,
An average torque calculator that calculates the average load torque of the motor from the difference between the rotational speed command value and the actual motor rotational speed obtained via the rotational position estimating unit from the actual current value detected by the current sensor When,
A torque pattern storage unit that stores a normalized torque pattern that serves as a reference for varying the output torque of the motor according to the rotational position of the motor;
Torque for correcting a current value supplied to the motor by generating a compensation torque pattern for varying the output torque of the motor according to the rotational position of the motor by the product of the average load torque and the normalized torque pattern A control unit;
The motor control apparatus that is connected to the compressor comprising the. A motor control device that is connected to a compressor and controls the rotational speed of the motor by an AC power source and an inverter ,
A speed control unit for setting a current command value to be supplied to the motor via the inverter in order to rotate the motor at a target rotational speed;
A current sensor for detecting an actual current value supplied to the motor;
With estimates the rotational position of the motor from the actual current value, and the rotational position estimation unit having the actual rotation speed calculation function corresponding to the rotational position of the motor from the current value,
An average torque calculator that calculates the average load torque of the motor from the difference between the rotational speed command value and the actual motor rotational speed obtained via the rotational position estimating unit from the actual current value detected by the current sensor When,
A torque pattern storage unit storing a plurality of normalized torque patterns serving as a reference for varying the output torque of the motor according to the rotational position of the motor;
Based on the product of one normalized torque pattern selectively obtained from the torque pattern storage unit based on the operating state of the motor and the average load torque, the output torque of the motor is determined according to the rotational position of the motor. A torque control unit for generating a compensation torque pattern for changing according to a load and correcting a current value supplied to the motor;
A motor control device connected to a compressor, comprising:   The torque control unit selects a normalized torque pattern corresponding to the magnitude of the average load torque of the motor calculated by the average torque calculation unit from the plurality of normalized torque patterns, and generates the compensation torque pattern. The control apparatus of the motor connected to the compressor of Claim 2 characterized by the above-mentioned. Prior Symbol torque control unit, according to claim 2 or 3, characterized in that to select the normalized torque pattern from said plurality of normalized torque patterns corresponding to the rotational speed fluctuation width of the motor, to generate the compensating torque pattern The control apparatus of the motor connected to the compressor of description. The torque control unit selects a normalized torque pattern corresponding to a rotation position and a rotation speed of the motor estimated by the position estimation unit from the plurality of normalized torque patterns, and generates the compensation torque pattern. a motor connected to the controller to the compressor according to any one of claims claim 2 to 4,. The torque control unit selects a normalized torque pattern corresponding to a motor current peak value detected by the current sensor from the plurality of normalized torque patterns, and generates the compensation torque pattern. or a motor connected to the controller to the compressor according to any one of the 5. The torque control unit calculates a torque difference value between the two normalized torque patterns in a switching state from one of the plurality of normalized torque patterns to the other normalized torque pattern, and calculates a torque difference value before switching. a motor connected to the controller to the compressor according to any one of claims 2 to 6, characterized in that generating said compensating torque pattern while reducing at a constant rate. In the switching state from one of the plurality of normalized torque patterns to another normalized torque pattern, the torque control unit is configured such that the load torque of both patterns at the rotational position of the motor estimated by the position estimation unit is a small angle. control apparatus for a motor connected to the compressor according to any one of claims 2 to 7, characterized in that the switching. The torque control unit normalizes a threshold value for selecting the other normalized torque pattern from another normalized torque pattern in a switching state from one of the plurality of normalized torque patterns to another normalized torque pattern. The threshold value for selecting one normalized torque pattern is set to one normalized torque pattern in a switching state from one of the plurality of normalized torque patterns to one normalized torque pattern larger or smaller than in the case of torque pattern switching. from other connected motor controller to the compressor according to any one of claims 2 to 8, characterized in that determining in larger or smaller than that of the normalized torque pattern switching. The torque control unit is connected to the compressor according to any one of claims 2 to 9, characterized in that adjusting the compensation torque pattern over a predetermined modulation factor to the compensation torque pattern Motor control device. The torque control section, at only a partial section of the rotation angle of the motor to increase or decrease the normalized torque pattern, according to any one of claims 1 to 9, characterized in that adjusting the compensation torque pattern Control device for motor connected to compressor.   The said torque control part correct | amends the electric current value supplied to the said motor so that the width | variety of the rotation speed of the said motor may become small, Control of the motor connected to the compressor of Claim 10 or 11 characterized by the above-mentioned. apparatus.

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