JP2007040281A - Reciprocating compressor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for reducing the power consumption of a reciprocating compressor in use for a refrigerator by performing simple control with a processor having low processing capability. <P>SOLUTION: One rotation cycle of a synchronous motor is divided into a section A for a time before the top dead center of the compressor and a section B for a time after the top dead center. The duty range of PWM control is changed so that a motor current less flows in the section A and the motor current more flows in the section B. This improves the volume efficiency of the reciprocating compressor to reduce power consumption. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inverter-driven reciprocating compressor mainly used in a refrigerator-freezer.

  Brushless motors have high efficiency, and in recent years, they have come to be used in many compressors used in refrigeration systems. For this reason, in the refrigerator-freezer, when the temperature in the refrigerator is stable, the rotational speed is reduced, the efficiency of the entire refrigeration system including the compressor is increased, and energy saving is realized.

  In a reciprocating compressor often used in a refrigerator-freezer, a piston reciprocates in a cylinder, half of one rotation is a refrigerant suction process, and the other half is a compression / discharge process. At the top dead center at the end of the discharge process, some high-pressure refrigerant remains, and the process proceeds to the suction process. For this reason, in the initial stage of the suction process, the expansion pressure of the residual gas is also applied, and almost no load torque is required, but a large load torque is required in the compression / discharge process.

  On the other hand, the motor torque of the brushless motor produces a substantially constant torque during one rotation. Therefore, a slight fluctuation in the number of rotations (that is, angular velocity) occurs during one rotation due to the relationship between the load torque and the motor torque. That is, the rotation speed decreases in the compression process, and the rotation speed increases in the suction process. This rotational speed fluctuation causes vibration. Since the moment of inertia of the compressor rotation system (rotor, shaft, piston, etc.) decreases as the rotation speed decreases, the vibration increases as the rotation speed decreases.

  Next, it considers from a viewpoint of refrigerant | coolant discharge amount. In the compression process, the discharge hole from the cylinder becomes a resistance, so the pressure inside the cylinder is higher than the pressure outside the cylinder. For this reason, the longer the time for which the piston is maintained near the top dead center, the greater the amount of refrigerant discharged from the cylinder, that is, the smaller the amount of refrigerant remaining, so-called volumetric efficiency is improved.

  On the other hand, if the passing time to the top dead center is short in the compression process, the volume efficiency is lowered.

  For the above-mentioned vibration phenomenon, conventionally, there has been an effort to suppress the vibration of the compressor by generating a motor torque that matches the load torque at a low speed rotation and suppressing a fluctuation in the rotation speed during one rotation. (For example, refer to Patent Document 1).

  A conventional compressor control device will be described below with reference to the drawings.

  FIG. 4 is a longitudinal sectional view of a conventional general reciprocating compressor. The rotor 22 is fitted with a brushless motor 2 including a stator 21 having a three-phase winding in a hermetic container 1 and a rotor 22 having a permanent magnet, a cylinder 5, a piston 6 and the like disposed on the bearing body 4. And a compression mechanism portion including a rotary shaft 3 and the like for converting the rotational motion into the reciprocating motion of the piston 6 by the eccentric portion 31. In general, an internal vibration isolation structure is used in a reciprocating compressor, that is, discharged from a support spring 8 that supports a structure composed of the brushless motor 2 and the compression mechanism, or from the compression mechanism. A method of attenuating the vibration of the structure due to torque fluctuation generated according to the load by the loop pipe 9 or the like for guiding the generated gas and controlling the vibration or noise is employed.

  In the reciprocating compressor, the rotor 22 and the rotating shaft 3 should have an appropriate moment of inertia, together with a structure that attenuates the vibration of the structure by the support spring 8 and the loop pipe 9. Therefore, it is devised so that vibration is not transmitted to the outside of the sealed container 1.

  However, when this reciprocating compressor is controlled to change the rotational speed using inverter control, vibration suppression by the moment of inertia has reached its limit, especially at the low rotational speed, and vibration suppression measures other than the moment of inertia Is required.

  In response to these phenomena, conventionally, efforts have been made to suppress the vibration of the compressor by generating a motor torque that matches the load torque at a low speed rotation and suppressing a fluctuation in the rotation speed during one rotation. (For example, refer to Patent Document 1).

  FIG. 5 shows a relationship diagram between load torque and motor torque of a conventional compressor.

In FIG. 5, as a method for controlling the motor torque, a method in which a position detecting element is installed in the motor, instantaneous torque is detected, and feedback to the motor output is most effective. In the case where the pressure condition for gas compression is determined by linking to a certain degree of temperature, the motor output torque pattern is set in advance according to the ambient temperature, the internal temperature, and the rotation speed, and the optimum pattern according to the change in the condition. It is also possible to select a method. The difference between the load torque and the motor output torque becomes zero or greatly reduced by applying torque to the motor whose absolute value is equal to or almost equal to the fluctuation pattern of the load torque. The vibration transmitted to is greatly reduced.
JP 2003-4352 A

  However, the conventional configuration has a problem that when the load torque and the motor torque are controlled so as to completely coincide with each other in order to completely stop the vibration, the input power becomes large. Further, since the decrease in the rotational speed in the compression process is reduced, the gas remaining in the cylinder is increased, the volumetric efficiency is also lowered, and the refrigeration system efficiency is lowered accordingly.

  In particular, when mounted on a refrigerator cooling system, most refrigerators are operated with the door closed, so most of the operations are performed at a low rotational speed. Therefore, although this control is performed to suppress vibration at a low rotational speed, as described above, there is a problem that input power increases and volume efficiency decreases and power consumption increases. It becomes.

  Further, since the motor torque, that is, the motor current is changed in accordance with the fluctuation of the load torque, it is necessary to control the current after detecting the motor current so as to coincide with the load torque. As a result, the control device has become larger, for example, a current sensor and peripheral circuits are required, and a processor (for example, a DSP or a 32-bit RISC microcomputer) capable of high-speed processing with high processing capability is also required. , Had the problem of higher prices.

  An object of the present invention is to solve the above-described conventional problems, and to provide a control device for a reciprocating compressor with low power consumption as a refrigerator by performing simple control using a processor with low processing capacity. And

  In order to solve the above conventional problems, the control device for the reciprocating compressor according to the present invention divides the section A from the time before the top dead center of the compression element during one rotation of the synchronous motor, and inputs the input in the section A. It comprises control means for controlling and making the motor rotation speed smaller than a predetermined motor rotation speed.

  As a result, the amount of refrigerant discharged from the cylinder increases, that is, the remaining amount of refrigerant decreases, so that so-called volumetric efficiency is improved.

  The control device for a reciprocating compressor according to the present invention divides one rotation of the reciprocating compressor into sections, changes the number of rotations during one rotation, and controls the motor current in each section, thereby providing a new Since it can be realized with a processor with low processing capability without requiring a sensor, the power consumption can be reduced with a simple system that can be realized with a very small size and low cost.

  The invention described in claim 1 is a reciprocating compressor having a reciprocating compression element, a synchronous motor having a permanent magnet for driving the compression element in a rotor, an alternating current flowing through the synchronous motor and a rotational speed. An inverter for making the compressor's refrigeration capacity variable by changing the speed, and dividing the section A from the time before the top dead center of the compressor during one rotation of the synchronous motor and controlling the input in the section A By having the control means for making the rotation speed smaller than the predetermined motor rotation speed, the amount of refrigerant discharged from the cylinder increases, that is, the remaining refrigerant amount decreases, so-called volume efficiency is improved. By controlling the motor current in each section, the power consumption can be reduced with a very simple system, and it can be realized in an easy way without using a current sensor, etc., so the device does not become large Therefore, it is not necessary to use a high-speed processor for the processing, and the cost can be reduced.

  According to a second aspect of the present invention, in the first aspect of the invention, the section B is divided from the time after the top dead center of the compressor, the input in the section B is controlled, and the motor rotational speed is set to a predetermined motor speed. By making the control means larger than the number, by making it lower than the predetermined motor rotation speed in the section A at the time before the top dead center, the slower rotation speed is compensated, and the average rotation speed of the entire motor rotation is determined by the predetermined motor rotation speed. It can be returned to the rotation speed. Thereby, the fall of the refrigerating capacity of a compressor can be prevented.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the number of cylinders of the reciprocating compressor is 1 (single cylinder). Since it can only be divided once and easily, control becomes easy.

  In the invention according to claim 4, in the invention according to any one of claims 1 to 3, the section A and the section B are separated and the input is a control method for changing the duty width of the PWM control of the inverter. Since it can be realized by an easy method without using a sensor or the like, the apparatus is not increased in size, it is not necessary to use a high-speed processor for the processing, and the cost can be reduced.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the reciprocating compressor is used in a refrigeration system of a refrigerator, and the effect of reducing power consumption is increased. .

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

(Embodiment 1)
FIG. 1 is a block diagram of a reciprocating compressor control apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, electric power necessary for driving is supplied from a commercial power source 100. For example, in the case of Japan, it is an AC power supply, and is a power supply of 100 V 50 Hz or 60 Hz.

  The rectifier circuit 101 converts the commercial power supply 100 into direct current. Here, the rectifier circuit 101 is shown as a full-wave rectifier circuit. A full-wave rectifier circuit is generally composed of four diodes and a smoothing capacitor connected in a bridge. With this circuit, a DC voltage of 140 V is obtained from the AC 100 V of the commercial power supply 100.

  The inverter 102 converts the DC voltage of the rectifier circuit 101 into three-phase AC again. The inverter 102 is generally composed of six switching elements (indicated by IGBT in the figure) connected in a three-phase bridge and six diodes connected in reverse to the switching elements in parallel. By controlling these six switching elements, a three-phase alternating current having an arbitrary voltage and an arbitrary frequency can be obtained.

  Synchronous motor 103 is driven by the three-phase AC output of inverter 102. It consists of a stator (not shown) with three-phase windings and a rotor (not shown) with permanent magnets. For example, the stator is a 9-slot tooth wound directly through insulating paper, and a 3-phase 6-pole winding is star-connected. The rotor has 6 permanent magnets on the surface side with N and S poles. And embedded magnet type rotors arranged alternately.

  The output from the inverter 102 can be set to an arbitrary voltage / arbitrary frequency, and the synchronous motor 103 has 6 poles. Therefore, the synchronous motor 103 is driven at a frequency (rotational speed) that is one third of the output frequency of the inverter 102. The For example, when the output frequency of the inverter 102 is 60 Hz, the synchronous motor 103 can be driven at a rotation speed of 20 r / s.

  The compression element 104 is driven by a synchronous motor 103 and performs compression work. Here, the compression element 104 is a reciprocating compression element whose load torque fluctuates during one rotation. In the case of a single-cylinder reciprocating type compression element, compression is performed by reciprocating movement of the piston. During one rotation, the half is completely separated from the suction process, and the half is completely separated from the compression process. Since the required load torque is concentrated on the compression process side, the load torque varies greatly.

  The compressor 105 stores the synchronous motor 103 and the compression element 104 in a sealed container. It goes without saying that any refrigerant gas may be used, and any refrigerant gas such as an alternative refrigerant (R-134a, etc.) or a natural refrigerant (R-600a, CO2, etc.) may be used.

  The compressor 105 has a discharge pipe (not shown) that discharges the compressed refrigerant and a suction pipe (not shown) that sucks the refrigerant. A condenser 106, a decompressor 107, an evaporator 108, and the like are connected in series to the discharge pipe, and finally the refrigerant gas returns from the suction pipe to the compressor 105. By assembling such a refrigerating and air-conditioning system, a heat dissipation action occurs on the condenser 106 side and a heat absorption action occurs on the evaporator 108 side, so that heating or cooling can be performed. In addition, a fan motor (not shown) is attached to the condenser 106 or the evaporator 108, and the efficiency of heat exchange is increased by sending air to efficiently heat or cool these heat. can do.

  The driving device 109 drives the inverter 102. The output drives the six switching elements of the inverter 102 via the drive means 110.

  In general, when driving a synchronous motor 103 having a permanent magnet as a rotor, the six switching elements of the inverter 102 are commutated at optimum positions while detecting the rotational position of the rotor, thereby synchronizing the rotor. The motor 103 is moved optimally. In general, a motor using this method is sometimes referred to as a brushless DC motor or a brushless motor.

  Further, the contents of the control device 109 will be described in detail.

  The position detector 111 detects the rotational position of the rotor of the synchronous motor 103. In general, a method of detecting a counter electromotive voltage generated in the stator winding of the synchronous motor 103 is well known. Recently, a synchronous motor such as a method of estimating a rotational position from a motor current or a current of a direct current section is used. Event information from 103 is often used. Of course, there is a method of directly detecting the position using a magnetic sensor such as a Hall element. However, since it is difficult to attach such a sensor to the compressor, the former method (position sensorless method) is often used. Yes.

  In such a position sensorless system, since position detection is impossible at the time of start-up, a predetermined phase (for example, between U and W) of the synchronous motor 103 called positioning is forcibly energized before start-up so that the rotor is predetermined. A control circuit such as a method of rotating to a position or a forcible drive system for forcibly applying an AC waveform of a predetermined frequency and a predetermined voltage to drive the rotor is also necessary, but is omitted here.

  The commutation means 112 determines the timing for energizing the six switching elements of the inverter 102 based on the output of the position detection means 111. In general, the timing is determined so that the phase of the counter electromotive voltage coincides with the phase. However, in the case of a magnet-embedded motor (generally called an IPM motor), the reluctance torque is also taken into consideration, and the motor current is slightly increased. There are also cases in which the operation is advanced with respect to the phase of the counter electromotive voltage. Although this phase advance varies depending on the type of motor (especially the amount of reluctance component used), it is common to have an advance angle of about 0 to 10 degrees.

  The rotational position determination means 113 detects the rotational position of the rotor of the synchronous motor 103, and the synchronous motor 103 is operated completely in synchronization with the output from the inverter 102. Therefore, by analyzing this signal, the mechanical rotational position of the rotor of the synchronous motor 103 can be determined.

  In the first PWM generating means 114, the duty of PWM (pulse width modulation) control (predetermined period, which refers to the ratio of the ON width in the carrier period) is adjusted in order to keep the rotation speed of the synchronous motor 103 constant. Output things.

  The second PWM generating means 115 generates a duty (for example, 10%) obtained by subtracting a predetermined amount of duty from the duty determined by the first PWM generating means 114. The third PWM generation means 118 generates a duty (for example, 10%) that is a predetermined duty increased from the duty determined by the first PWM generation means 114. Here, the increasing / decreasing duty is a fixed value, but may be changed depending on the rotational speed and load conditions.

  The selection means 116 always selects the PWM signal of the first PWM generation means 114 when the rotational speed is high. When the rotational speed is low, the rotational position signal of the rotational position determining means 113 is received and a predetermined section A and section B are determined. In the case of the section A, the PWM signal of the second PWM generating means 115 is selected. In the section B, the PWM of the third PWM generation means 118 is selected, and in the other sections, the PWM signal of the first PWM generation means 114 is selected.

  The commutation output of the commutation means 112 and the PWM signal of the selection means 116 are synthesized by the synthesis means 117 and output to the drive means 117 to control the inverter 102.

  The operation of the reciprocating compressor control apparatus configured as described above will be described in more detail with reference to FIGS. FIG. 2 is a control flowchart of the reciprocating compressor control apparatus according to Embodiment 1 of the present invention.

  In step 1, the rotational speed is detected. Since the motor used in the present invention is a synchronous motor, the electrical frequency output from the inverter 102 and the rotational operation of the synchronous motor 103 coincide with each other. Can be detected. Although the number of rotations is used here, it may be the same as the number of rotations, for example, a rotation cycle or an angular velocity.

  Next, in STEP2, it is determined whether the rotational speed is equal to or less than a predetermined value. The predetermined value here is set to a low rotational speed, and in a normal application, it is the rotational speed at which the compressor is stably operated, and is set to a rotational speed with a large energy saving effect (for example, 20 r / s). Has been.

  The rotation speed larger than the predetermined rotation speed is a normal operation because the refrigeration system is in an operation state during a cooling transition period such as a high load condition and the total operation time is short, and even if the control according to the present invention is performed, the energy saving effect is small. Therefore, in STEP3, the output of the first PWM generation means 114 is selected by the selection means 116, and the operation is performed at the first PWM. Of course, if it is applied even in the high rotation range, a little energy saving effect can be expected.

  Further, the predetermined value is determined by the configuration of the refrigeration air conditioning system, the type of the compressor, and the like, and is set based on the low speed rotation speed with a long operation time. Of course, a predetermined value that varies depending on the surrounding environment state (temperature, etc.) and the driving state may be determined.

  On the other hand, if it is equal to or lower than the predetermined rotation speed, the process proceeds to STEP 4 to determine whether or not the operation is stable. The determination of the stable operation may be made from the temperature condition of each part in the refrigeration air-conditioning system control device (not shown) or the elapsed time. When it is determined that the operation is not stable, that is, during the transition period, it is important that the operation is stable. Therefore, the process proceeds to STEP 3 and the operation is performed at the first PWM.

  If it is determined in STEP4 that the operation is stable, the process proceeds to STEP5. In STEP 5, the rotation position determination means 113 determines, and it is determined whether or not the rotation position is the section A. The rotational position determination means 113 is adapted to determine the mechanical rotational angle in advance, and the section of the mechanical angle of 120 degrees before the top dead center of the piston (not shown) of the compression element 104 is defined as section A. It is said. If it is determined in STEP 5 that the rotational position is section A, the process proceeds to STEP 6. In STEP 6, the output of the second PWM generation means 115 is selected by the selection means 116, and the operation is performed at the second PWM.

  If it is determined in STEP 5 that the rotational position is not the section A, the process proceeds to STEP 7 and it is determined whether or not the rotational position is the section B. The rotational position determining means 113 is adapted to know the mechanical rotational angle in advance, and the section of the mechanical angle of 120 degrees behind the piston (not shown) of the piston (not shown) of the compression element 104 is defined as section B. It is said. If it is determined in STEP5 that the rotational position is the section B, the process proceeds to STEP8. In STEP 8, the output of the third PWM generator 118 is selected by the selector 116, and the operation is performed at the third PWM.

  If it is determined in STEP 7 that the rotational position is not in the section B, the process proceeds to STEP 3 to operate at the first PWM.

  By operating as described above, when a stable operation is performed at a low rotational speed, the operation is performed at the second PWM in the section A, at the third PWM in the section B, and at the first PWM in the other sections. Since the duty of the second PWM is set to be smaller than the duty of the first PWM, the current in the section A is smaller than the current in the section B. Therefore, a small torque is generated in the section A. Since the section A is set before the top dead center of the compression element, the torque is reduced during compression, the rotation speed is reduced, and the time during which the refrigerant in the compressed cylinder is discharged is discharged. The so-called volumetric efficiency is improved by increasing the length and reducing the amount of refrigerant remaining in the cylinder.

  Next, the actual operation will be described with reference to FIG. FIG. 3 is a control timing chart of the control device for the reciprocating compressor according to the first embodiment of the present invention.

  In FIG. 3, the horizontal axis indicates the movement of the synchronous motor 103 during one rotation. A broken line written on the horizontal axis indicates the mechanical rotation state detected by the position detecting means 111, and one segment indicates 1 / 18th rotation. In this embodiment, since the synchronous motor 103 has six poles, the mechanical rotation state per one electrical angle cycle (1/3 rotation and 2/3 rotation) is further indicated by a one-dot chain line. Yes. The origin portion (0 rotation) indicates the top dead center portion of the piston of the compression element 104.

  As for torque, load torque and motor torque are shown. Since the compressor 105 is a single-cylinder reciprocating compressor, the load torque is used in the compression / discharge process after half of the mechanical rotation state. The load torque increases rapidly as shown. On the other hand, at the initial angle of the next mechanical rotation state, the load torque decreases due to re-expansion of the refrigerant remaining in the cylinder.

  On the other hand, the motor torque generates a substantially constant torque per rotation. Strictly speaking, the motor torque automatically changes as shown in Patent Document 1 when the inertial moment is small at a low rotation speed in accordance with the change of the load torque. The torque was constant.

  The angular velocity fluctuates during one rotation, and the angular velocity is accelerated when “motor torque> load torque”, while the angular velocity is decelerated when “motor torque <load torque”.

  The positions of the position signals X, Y, and Z change every 1 / 18th rotation (that is, every 20 degrees) of the mechanical rotation state. In normal control, the driving signals U (upper arm and lower arm), V (upper arm and lower arm), W (upper arm and lower arm) are determined according to a predetermined logical expression in accordance with the position signals X, Y, and Z. Is generated.

  Section A is 120 degrees (1/3 rotation) before the top dead center, and section B is 120 degrees (1/3 rotation) after the top dead center. As the PWM signal, the second PWM is selected in the section A, the third PWM is selected in the section B, and the first PWM is selected in the other sections.

  In FIG. 3, the U-phase current is also shown. In the section A, since the second PWM is operated, the duty is small and the current is small. In section B, since the operation is performed at the third PWM, the duty is large and the current is large.

  As described above, the reciprocating compressor control apparatus according to the first embodiment includes a reciprocating compressor 105 having a reciprocating compression element 104 and a synchronous rotor having a permanent magnet for driving the compression element 104 in a rotor. A motor 103, an inverter for supplying an alternating current to the synchronous motor and changing the number of rotations to change the refrigeration capacity of the compressor, and a time before the top dead center of the compressor during one rotation of the synchronous motor And the control means for controlling the input in the section A and making the motor rotation speed smaller than the predetermined motor rotation speed, the amount of refrigerant discharged from the cylinder increases, that is, the remaining refrigerant volume So that so-called volumetric efficiency is improved. By controlling the motor current in each section, the power consumption can be reduced with a very simple system, and it can be realized in an easy way without using a current sensor, etc. There is no need to use a high-speed processor for the processing, and the cost can be reduced.

  In addition, the time before the top dead center is obtained by the control means that divides the section B from the time after the top dead center of the compressor and controls the input in the section B to make the motor rotation speed larger than the predetermined motor rotation speed. By making it smaller than the predetermined motor rotational speed in the section A, it is possible to compensate for the slowed rotational speed and return the average rotational speed of the entire rotation of the motor to the predetermined rotational speed. Thereby, the fall of the refrigerating capacity of a compressor can be prevented.

  In addition, since the number of cylinders of the reciprocating compressor is 1 (single cylinder), there is only one suction process and one compression process in each rotation of the motor, and the control can be easily performed because it can be easily classified.

  In addition, since the section A and the section B are divided and input is a control method for changing the duty width of the PWM control of the inverter, it can be realized by an easy method without using a current sensor or the like, so that the apparatus becomes large. There is no need to use a high-speed processor for the processing, and the cost can be reduced.

  In addition, by using this technology especially for refrigerator cooling systems, it is possible to reduce power consumption particularly in refrigerator cooling systems that are often driven at low speeds by reciprocating compressors. It becomes.

  As described above, the reciprocating compressor control apparatus according to the present invention does not require a new sensor and can be realized with a processor with low processing capacity, so it is a simple system that can be realized with a very small size and low cost. Power consumption can be reduced. Although some control is complicated, it can also be applied to a multi-cylinder reciprocating compressor, and is effective for a compression device that improves volumetric efficiency by reducing the number of revolutions during the compression process. In addition to a compressor for refrigeration, it can be applied to uses such as an air compressor.

1 is a block diagram of a reciprocating compressor control apparatus according to Embodiment 1 of the present invention. Flowchart of control of control device for reciprocating compressor in embodiment 1 of the present invention Timing chart of control of control device for reciprocating compressor according to Embodiment 1 of the present invention Longitudinal sectional view of a conventional general compressor Relationship diagram between conventional compressor load torque and motor torque

Explanation of symbols

102 Inverter 103 Synchronous motor 104 Compression element 105 Compressor 109 Control device

Claims (5)

  A reciprocating compressor having a reciprocating compression element, a synchronous motor having a permanent magnet for driving the compression element in a rotor, an alternating current flowing through the synchronous motor and a variable number of rotations, and the compressor And an inverter for making the refrigerating capacity variable, and the synchronous motor is rotating once, and section A is divided from the time before the top dead center of the compressor, and the motor speed is controlled by controlling the input in section A A control device for a reciprocating compressor comprising control means for making the rotational speed smaller than a predetermined motor speed.   From the control means which divides the section B from the time after the top dead center of the compressor during one rotation of the synchronous motor, and controls the input in the section B to make the motor rotation speed larger than a predetermined motor rotation speed The reciprocating compressor control device according to claim 1.   The reciprocating compressor control device according to claim 1, wherein the reciprocating compressor is a single cylinder.   4. The control device for a reciprocating compressor according to claim 1, wherein the input of the section A and the section B changes a duty width of PWM control of the inverter. 5.   The reciprocating compressor control apparatus according to any one of claims 1 to 4, wherein the reciprocating compressor is used in a refrigerator refrigeration system.

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