JP2019004592A - Compressor system - Google Patents

Abstract

Provided is a compressor system that can use a general-purpose electric compressor and can more reliably suppress an increase in casing temperature when the casing temperature rises. In the compressor system, a motor housing is provided for each of the casing in which the compression mechanism section and the motor section are housed, an inverter that supplies three-phase AC power to the motor section, and each phase of the three-phase AC power. Detected by the current detection means, the current detection means for detecting the current value of each of the two-phase power supply lines of the three-phase power supply lines, and the current detection means Based on the two-phase current value, the remaining one-phase current value of the three-phase AC power is obtained, and the control device that controls the inverter using the obtained three-phase current value and the current detection means detect the current value. Current blocking means that is provided on one of the two-phase power supply lines and that electrically disconnects the one power supply line when the temperature of the housing becomes equal to or higher than the first reference temperature. [Selection] Figure 1

Description

  The present invention relates to a compressor system.

  As a compressor system, a system in which a bimetal thermal overload protection device is provided at a neutral point of a three-phase winding of a three-phase motor of an electric compressor is known (for example, see Patent Document 1).

Japanese Utility Model Publication No. 63-007969

  However, in the compressor system as shown in Patent Document 1, the neutral point of the three-phase winding of the electric compressor is accommodated in a sealed container of the electric compressor. For this reason, even if it is going to use a general purpose electric compressor, it is difficult to attach an overload protection device to the neutral point of a three-phase winding, and a general purpose electric compressor cannot be used. On the other hand, when a temperature sensor such as a thermistor is attached to the outside of the casing of the electric compressor and the electric power supplied to the electric compressor is controlled according to the detection result of the temperature sensor, if some abnormality occurs on the control side, It becomes impossible to suppress the rise in the casing temperature.

  The present invention has been made to solve such problems. The purpose is to ensure that when a general-purpose electric compressor can be used and the housing temperature rises due to an abnormality such as a lock of the electric motor section that drives the compression mechanism section of the electric compressor. An object of the present invention is to obtain a compressor system capable of suppressing an increase in housing temperature.

  A compressor system according to the present invention includes a compression mechanism unit for compressing a gas and a housing in which an electric motor unit that drives the compression mechanism unit is housed, an inverter that supplies three-phase AC power to the electric motor unit, Provided for each phase of the three-phase AC power, a power supply line that electrically connects the stator coil of the motor unit and the inverter, and each of the two phases of the three-phase power supply lines Current detection means for detecting the current value of the feeder line, and the current value of the remaining one phase of the three-phase AC power based on the two-phase current value detected by the current detection means, A control device that controls the inverter using a current value, and a first that is provided in one of the two-phase power supply lines in which the current detection means detects the current value, and the temperature of the housing is preset. When the temperature exceeds the reference temperature And a current interruption means for electrically disconnecting said one of said feed line.

  According to the compressor system of the present invention, it is possible to use a general-purpose electric compressor, and the housing temperature rises due to an abnormality such as a lock of the electric motor unit that drives the compression mechanism unit of the electric compressor. When it does, there exists an effect that the raise of housing | casing temperature can be suppressed more reliably.

1 is a schematic diagram of an overall configuration of a compressor system according to Embodiment 1 of the present invention. It is the schematic diagram which looked at the housing | casing with which the compressor system which concerns on Embodiment 1 of this invention is provided from the upper surface side. It is a flowchart which shows operation | movement of the compressor system which concerns on Embodiment 1 of this invention.

  DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and overlapping descriptions are simplified or omitted as appropriate. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit of the present invention.

Embodiment 1 FIG.
FIGS. 1 to 3 relate to Embodiment 1 of the present invention. FIG. 1 is a schematic view of the overall configuration of the compressor system, and FIG. 2 is a schematic view of the casing of the compressor system as viewed from the top side. FIG. 3 is a flowchart showing the operation of the compressor system.

  The compressor system according to Embodiment 1 of the present invention includes a housing 1 as shown in FIG. The housing 1 accommodates a compression mechanism section and an electric motor section 100 (not shown) inside. The housing 1 is a hollow sealed container made of steel, for example. A compression mechanism part is for compressing gas. The compression mechanism part accommodated in the housing | casing 1 is a part or all of a known gas compression mechanism. Specific examples of known gas compression mechanisms include scroll-type and rotary-type gas compression mechanisms.

  The electric motor unit 100 is for driving the compression mechanism unit. The electric motor unit 100 is a synchronous motor. The electric motor unit 100 includes a stator, a rotor, a rotating shaft, and the like (not shown). A well-known thing can be employ | adopted for structures, such as a stator, a rotor, and a rotating shaft, with which the electric motor part 100 is provided. That is, as an example, it is configured as follows.

  A permanent magnet is embedded in the rotor. A rotating shaft is fixed at the center of the rotor. The rotating shaft of the electric motor unit 100 is connected to the compression mechanism unit. The stator is arranged so as to surround the rotor. The stator is for generating a magnetic force acting on the rotor. The stator has a stator core. The stator core is formed by laminating a plurality of iron plates. The stator is configured by winding a coil around the stator core.

  Specifically, the electric motor unit 100 includes a first stator coil 111, a second stator coil 112, and a third stator coil 113. Hereinafter, the first stator coil 111, the second stator coil 112, and the third stator coil 113 may be collectively referred to simply as “stator coils”. One end of the first stator coil 111, one end of the second stator coil 112, and one end of the third stator coil 113 are electrically connected to each other. This connection point forms a neutral point.

  The other end of the first stator coil 111 is connected to the first terminal 121 shown in FIG. The first power supply line 11 is electrically connected to the first terminal 121. The other end of the second stator coil 112 is connected to the second terminal 122 shown in FIG. The second power supply line 12 is electrically connected to the second terminal 122. The other end of the third stator coil 113 is connected to a third terminal 123 shown in FIG. The third power supply line 13 is electrically connected to the third terminal 123. Hereinafter, the first power supply line 11, the second power supply line 12, and the third power supply line 13 may be collectively referred to simply as “power supply lines”.

  These feeders electrically connect the stator coil of the motor unit 100 and the inverter 2. The inverter 2 supplies three-phase AC power to the electric motor unit 100. A power supply line is provided for each phase of the three-phase AC power. That is, the first power supply line 11, the second power supply line 12, and the third power supply line 13 correspond to the respective phases of the three-phase AC power.

  A first current transformer 21 is inserted in the first power supply line 11 that connects the inverter 2 and the first stator coil 111. A second current transformer 22 is inserted in the second feeder 12 that connects the inverter 2 and the second stator coil 112. The first current transformer 21 and the second current transformer 22 are both CT (Current Transformer). The current value of the first feeder 11 can be detected by the first current transformer 21. The current value of the second feeder 12 can be detected by the second current transformer 22. The first current transformer 21 and the second current transformer 22 constitute current detection means for detecting the current value of each of the two-phase feed lines among the three-phase feed lines.

  As shown in FIG. 1, the compressor system according to Embodiment 1 of the present invention includes a control device 3. The control device 3 controls the gas compression operation of the compressor system by mainly controlling the operation of the inverter 2. Specifically, the control device 3 is a control board on which a control circuit such as the inverter 2 is mounted.

  The control device 3 obtains the remaining one-phase current value of the three-phase AC power based on the two-phase current values detected by the first current transformer 21 and the second current transformer 22 which are current detection means. . More specifically, the sum of the three-phase current values of the three-phase AC power supplied from the inverter 2 to the motor unit 100 via the feeder line is zero. Therefore, the sign of the sum of the current value of the first feeder 11 detected by the first current transformer 21 and the current value of the second feeder 12 detected by the second current transformer 22 is reversed. Thus, the current value of the remaining third feeder 13 can be obtained.

  Then, the control device 3 controls the inverter 2 using the three-phase current values thus obtained. That is, the control device 3 detects the current value of the first feeder 11 detected by the first current transformer 21, the current value of the second feeder 12 detected by the second current transformer 22, and the The electric power supplied from the inverter 2 to the electric motor unit 100 is controlled using the current value of the third feeder 13 obtained by calculation from the current value.

  In the first embodiment, the control device 3 determines that the current value of any one of the three-phase feed lines, that is, the first feed line 11, the second feed line 12, and the third feed line 13 is a current reference. When it becomes more than the value, the power supply from the inverter 2 to the electric motor unit 100 is stopped. A specific value of the current reference value is set in advance.

  As shown in FIG. 1, the compressor system according to Embodiment 1 of the present invention includes a thermistor 4. Specifically, for example, the thermistor 4 is attached so as to contact the outer surface of the side portion of the housing 1. The thermistor 4 is temperature detection means for detecting the temperature of the housing 1. The thermistor 4 outputs an electrical signal corresponding to the temperature of the housing 1 from the detection.

  The control device 3 controls power supply to the electric motor unit 100 by the inverter 2 according to the electric signal output from the thermistor 4. Specifically, the control device 3 stops the power supply from the inverter 2 to the electric motor unit 100 when the temperature of the housing 1 detected by the thermistor 4 serving as the temperature detection means becomes equal to or higher than the temperature reference value. A specific value of the temperature reference value is set in advance.

  As shown in FIG. 1, the compressor system according to Embodiment 1 of the present invention includes an energization breaker 5. The energization breaker 5 is provided on one of the two-phase power supply lines for detecting the current value by the above-described current detection means. In the example described in the first embodiment, the two-phase power supply line whose current value is detected by the current detection means is the first power supply line 11 provided with the first current transformer 21 and the second power supply line. This is the second feeder 12 in which the current transformer 22 is provided. Accordingly, the energization breaker 5 is provided on one of the first power supply line 11 and the second power supply line 12. In the example described in the first embodiment, the energization breaker 5 is provided on the first power supply line 11.

  As shown in FIG. 2, the energization breaker 5 is attached so as to contact the upper surface of the housing 1, for example. Specifically, for example, a motor protector, a thermostat, a thermal fuse, or the like can be used as the energization breaker 5. When the temperature of the power breaker 5 reaches the operating temperature, the power breaker 5 electrically disconnects the first power supply line 11. A specific value of the operating temperature is set in advance. The operating temperature is specifically set to 110 ° C., for example. It may be considered that the temperature of the energization breaker 5 is the same as the temperature of the housing 1. Therefore, the fact that the temperature of the energizing circuit breaker 5 is equal to or higher than the operating temperature and the temperature of the housing 1 equal to or higher than the operating temperature can be regarded as the same.

  Thus, when the temperature of the housing 1 becomes equal to or higher than the operating temperature, the energizing circuit breaker 5 is a current interrupting means that electrically disconnects one of the power supply lines described above, here the first power supply line 11. Is configured. Here, the operating temperature is higher than the temperature reference value for the thermistor 4 described above. That is, in other words, the operating temperature is the first reference temperature, and the temperature reference value is the second reference temperature. The first reference temperature is higher than the second reference temperature.

  In addition, as shown in FIG. 2, the discharge pipe 6 is provided in the upper surface of the housing | casing 1 toward upper direction. The discharge pipe 6 is a pipe for sending the gas compressed by the compression mechanism part to the outside of the housing 1.

  Next, an operation flow of the compressor system configured as described above will be described with reference to FIG. During the gas compression operation of the compressor system, first, in step S1, the control device 3 determines whether or not there is an abnormality in the waveform of the current supplied from the inverter 2 to the electric motor unit 100. As described above, this determination is based on the current value of the first feeder 11 detected by the first current transformer 21 and the current value of the second feeder 12 detected by the second current transformer 22. The current value of the third feeder 13 obtained by calculation from these current values is used.

  If the current waveform is abnormal, the process proceeds to step S2. In step S2, the control device 3 outputs a compressor synchronization error. Then, when the process of step S2 is completed, the series of operation flow ends.

  On the other hand, if there is no abnormality in the current waveform in step S1, the process proceeds to step S3. In step S <b> 3, the control device 3 determines whether the current value of any of the three-phase power supply lines, that is, the first power supply line 11, the second power supply line 12, and the third power supply line 13 is equal to or greater than the current reference value. Determine whether or not.

  If the current value of any of the three-phase feeder lines is greater than or equal to the current reference value, the process proceeds to step S4. In step S4, the control device 3 outputs an overcurrent abnormality error. At this time, the control device 3 may stop the power supply from the inverter 2 to the electric motor unit 100. Then, when the process of step S4 is completed, a series of operation flows is completed.

  On the other hand, if none of the current values of the three-phase power supply lines is greater than or equal to the current reference value in step S3, the process proceeds to step S5. In step S5, the control device 3 determines whether or not the temperature of the casing 1 detected by the thermistor 4 is equal to or higher than a temperature reference value.

  If the temperature of the housing 1 detected by the thermistor 4 is equal to or higher than the temperature reference value, the process proceeds to step S6. In step S6, the control device 3 outputs a thermistor abnormality error. At this time, the control device 3 may stop the power supply from the inverter 2 to the electric motor unit 100. Then, when the process of step S6 is completed, a series of operation flow ends.

  On the other hand, if the temperature of the casing 1 detected by the thermistor 4 is not equal to or higher than the temperature reference value in step S5, the process proceeds to step S7. In step S7, the temperature of the energization breaker 5 becomes a problem. When the temperature of the energization breaker 5 reaches the operating temperature, the energization breaker 5 is activated, the first power supply line 11 is electrically interrupted (step S8), and the series of operation flow is completed. On the other hand, if the temperature of the energization breaker 5 does not reach the operating temperature, the series of operation flow is finished as it is. That is, when the temperature of the energization breaker 5 does not reach the operating temperature, the first power supply line 11 is maintained in an electrically connected state.

  In the compressor system configured as described above, when the electric motor unit 100 is locked, that is, even though electric power is supplied from the inverter 2 to the electric motor unit 100, the electric motor unit 100 has an abnormality due to some abnormality. Consider the case where the rotor stops rotating. When such a lock occurs, the power supply continues even though the electric motor unit 100 is not operating, so the temperatures of the electric motor unit 100 and the housing 1 rise abnormally.

  In this case, according to the flowchart of FIG. 3 described above, the control device 3 sequentially determines the current waveform, the current value, and the temperature of the casing 1 detected by the thermistor 4, and from the inverter 2 to the electric motor according to the determination result. The power supply to the unit 100 is stopped. However, since all the above determinations are performed by the control device 3, if an abnormality has occurred in the determination function portion of the control device 3, the power supply to the motor unit 100 cannot be stopped properly, There is a possibility that the temperature rise of the housing 1 cannot be stopped. Further, even when the thermistor 4 has an abnormality, the control device 3 cannot correctly stop the power supply to the electric motor unit 100 and the temperature of the housing 1 may continue to rise.

  On the other hand, the compressor system according to the first embodiment of the present invention includes the energization breaker 5 as described above. As described above, the operating temperature of the power breaker 5 is higher than the temperature reference value of the thermistor 4. Therefore, if the temperature of the housing 1 rises beyond the temperature reference value of the thermistor 4 due to an abnormality in the control device 3 or the like, the first power supply line 11 is not passed through the control device 3 but by the energization breaker 5. Can be electrically disconnected.

  When the first power supply line 11 is electrically disconnected, the electric motor unit 100 performs an operation in a state in which one phase of the three-phase alternating current is missing, that is, a so-called phase loss operation. Then, by causing the electric motor unit 100 to perform a phase loss operation, the amount of electric power supplied from the inverter 2 to the electric motor unit 100 can be suppressed, and the temperature rise of the housing 1 can be suppressed.

  Further, even when the temperature of the housing 1 rises due to a cause other than the lock of the electric motor unit 100, the temperature rise of the housing 1 can be suppressed by causing the electric motor unit 100 to perform a phase loss operation. At this time, it is also possible to suppress the generation of shocking sounds and vibrations by continuing the operation of the electric motor unit 100 in the phase loss operation without suddenly stopping the operation of the electric motor unit 100.

  Here, the energization breaker 5 is provided so that either the first power supply line 11 or the second power supply line 12 can be electrically disconnected instead of the third power supply line 13. The reason is as follows. First, as described above, with respect to the first feeder 11, the current value is directly detected by the first current transformer 21. Similarly, for the second feeder 12, the current value is directly detected by the second current transformer 22. On the other hand, for the third feeder 13, the first current transformer 21 and the second current transformer 22 do not directly detect the current value, and the first current transformer 21 and the second current transformer 21. The current value is obtained indirectly from the detected value of the current transformer 22 by calculation.

  Therefore, if the energization breaker 5 electrically disconnects the third feeder 13, even if the energization breaker 5 is activated and the current value of the third feeder 13 becomes zero, the first The current values of the first feeder line 11 and the second feeder line 12 do not become zero. For this reason, from the detection value by the 1st current transformer 21 and the 2nd current transformer 22, it cannot grasp | ascertain by the control apparatus 3 side that the electricity circuit breaker 5 act | operated. Therefore, despite the fact that the current breaker 5 is activated and the third power supply line 13 is electrically disconnected, the control device 3 causes the inverter to operate the motor unit 100 with normal three-phase AC power. 2 continues to be controlled, the motor unit 100 cannot be appropriately operated in a phase-opening manner, and rather than suppressing the temperature rise of the housing 1, the temperature of the housing 1 may be increased.

  On the other hand, when the energization breaker 5 is activated by causing the energization breaker 5 to electrically disconnect the first power supply line 11 or the second power supply line 12, the first current transformer The current value detected by 21 or the second current transformer 22 becomes zero. Therefore, from the detection value by the first current transformer 21 and the second current transformer 22, it can be grasped on the control device 3 side that the energization breaker 5 is activated. Therefore, the control device 3 appropriately controls the inverter 2 so as to cause the motor unit 100 to perform a phase-losing operation based on the detection values of the first current transformer 21 and the second current transformer 22 by the normal three-phase AC power. Can be controlled.

  The compressor system configured as described above has a motor protector, thermostat, or the like without depending on the control of the control device 3 when the casing temperature rises due to an abnormality such as a lock of the electric motor unit that drives the compression mechanism unit. By intentionally operating the motor unit in a phase-opening manner with the energization breaker 5 such as a thermal fuse, it is possible to more reliably suppress an increase in the housing temperature. At this time, the energization breaker 5 may be externally attached to the casing 1 of the electric compressor, and therefore can be easily applied to a general-purpose electric compressor.

DESCRIPTION OF SYMBOLS 1 Case 2 Inverter 3 Control apparatus 4 Thermistor 5 Power supply circuit breaker 6 Discharge pipe 11 1st electric power feeding line 12 2nd electric power feeding line 13 3rd electric power feeding line 21 1st current transformer 22 2nd current transformer 100 Electric motor unit 111 First stator coil 112 Second stator coil 113 Third stator coil 121 First terminal 122 Second terminal 123 Third terminal

Claims (3)

A housing that houses a compression mechanism section for compressing gas and an electric motor section that drives the compression mechanism section;
An inverter for supplying three-phase AC power to the motor unit;
A feed line that is provided for each phase of the three-phase AC power, and electrically connects the stator coil of the motor unit and the inverter;
Current detecting means for detecting a current value of each of the two-phase feed lines of the three-phase feed lines;
A control device for determining a current value of the remaining one phase of the three-phase AC power based on a two-phase current value detected by the current detection means, and controlling the inverter using the obtained three-phase current value; ,
When the current detection means is provided on one of the two-phase power supply lines for detecting a current value, and the temperature of the casing is equal to or higher than a first reference temperature set in advance, the one of the ones And a current interrupting means for electrically disconnecting the power supply line. Temperature detecting means for detecting the temperature of the housing;
When the temperature of the casing detected by the temperature detection unit is equal to or higher than a preset second reference temperature, the control device stops power supply from the inverter to the electric motor unit,
The compressor system according to claim 1, wherein the first reference temperature is higher than the second reference temperature.   The said control apparatus stops the electric power supply from the said inverter to the said motor part, when the electric current value of either of the said three-phase feeder line becomes more than the preset electric current reference value. Item 3. The compressor system according to Item 2.

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