JP2011151880A - Temperature abnormality decision device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine that there is temperature abnormality in any reactor among a plurality of reactors connected in parallel with one another. <P>SOLUTION: A motor drive control device 42 for a compressor includes a rectifier 51, an inverter part 55, two reactors 52 and 53, thermistors 52a and 53a, and a control part 56. A rectifier 51 rectifies an AC voltage. The inverter part 55 generates a drive voltage for driving a motor 41a for a compressor by using a DC voltage after rectification, and outputs it to the motor 41a. The two reactors 52 and 53 are connected in parallel with each other between the rectifier 51 and the inverter part 55. The thermistors 52a and 53a detect the temperature of each reactor 52 and 53. The control part 56, which functions as an abnormality determining part 56a, determines the temperature abnormality of the reactors 52 and 53 based on a reactor relative temperature ΔTd which shows a difference in temperature of reactors 52 and 53. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a temperature abnormality determination device, and more particularly to a device for determining whether or not a reactor temperature is abnormal.

  2. Description of the Related Art Conventionally, as a device for driving a motor which is a drive source such as a compressor or a fan in an air conditioner, a motor driving device as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 5-15169) is known. It has been. This motor drive device includes a rectification unit that rectifies an AC power supply, one reactor connected to the rectification unit, and an inverter unit that is connected to the subsequent stage of the reactor and drives the motor.

  When the motor driving device described above drives a motor for a compressor, the reactor needs to have a large capacity as the capacity of the compressor increases. Therefore, when the capacity of the compressor is so large that one reactor cannot cope with it, a method of connecting the reactors in parallel with each other can be considered. However, when this method is used, for example, if the wiring of one of the reactors is in a disconnected state, there is a possibility that current concentrates on another reactor. Since this phenomenon causes an accident or failure, the temperature abnormality of the reactor needs to be detected promptly.

  Therefore, an object of the present invention is to quickly determine that a temperature abnormality has occurred in any reactor.

  A temperature abnormality determination device according to a first aspect of the present invention includes a rectification unit, an inverter unit, a plurality of reactors, a temperature detection unit, and an abnormality determination unit. The rectification unit rectifies the AC power supply. An inverter part produces | generates the drive voltage for driving a motor using the power supply after rectification, and outputs this voltage to a motor. The plurality of reactors are connected in parallel to each other between the rectification unit and the inverter unit. The temperature detector detects the temperature of each reactor. The abnormality determination unit determines the temperature abnormality of the reactor based on the reactor relative temperature indicating the temperature difference between the reactors.

  In this temperature abnormality determination device, a reactor temperature abnormality is determined based on the relative temperature of the reactor in a state where a plurality of reactors are connected in parallel to each other. For example, if the relative temperature of the reactor is greater than or equal to a predetermined difference, it is determined that the temperature is abnormal in any reactor. Thus, by using the relative temperature of the reactor, it is possible to quickly determine that a temperature abnormality has occurred in any of the reactors. Therefore, it is possible to prevent an accident or failure from occurring due to a temperature abnormality in any of the reactors.

  The temperature abnormality determination device according to a second aspect of the present invention is the temperature abnormality determination device according to the first aspect, further comprising a first control unit. When the abnormality determination unit determines that a temperature abnormality has occurred in the reactor, the first control unit controls the inverter unit so that the inverter unit stops outputting the drive voltage.

  In this temperature abnormality determination device, when it is determined that the temperature is abnormal in any of the reactors, the output of the drive voltage to the motor by the inverter unit is stopped. That is, when there is a temperature abnormality in any reactor, the motor stops rotating, so that it is possible to prevent a failure and an accident from occurring in parts other than the reactor due to current concentration, and to ensure safety. .

  A temperature abnormality determination device according to a third aspect of the present invention is the temperature abnormality determination device according to the first aspect, wherein the motor is a compressor motor that is a drive source of a variable capacity compressor. The temperature abnormality determination device further includes a second control unit. When the abnormality determination unit determines that a temperature abnormality has occurred in the reactor, the second control unit controls the inverter unit such that the capacity of the compressor is reduced.

  In this temperature abnormality determination device, when it is determined that the temperature is abnormal in any of the reactors, the inverter unit reduces the rotation speed of the compressor motor so that the capacity of the compressor is reduced. Drive voltage is output. Therefore, it is possible to prevent a failure and an accident from occurring in parts other than the reactor due to current concentration, and to ensure safety.

  The temperature abnormality determination device according to a fourth aspect of the present invention is the temperature abnormality determination device according to any one of the first to third aspects, wherein the abnormality determination unit further includes a reactor based on the absolute value of the temperature of each reactor. It is possible to determine an abnormal temperature. Then, the abnormality determination unit determines that there is a reactor in which a temperature abnormality has occurred when the reactor relative temperature is equal to or greater than a predetermined difference, or when at least one of the absolute values of the temperatures of each reactor is equal to or greater than a predetermined value. To do.

  In this temperature abnormality determination device, if the reactor relative temperature is greater than or equal to a predetermined difference, or if at least one of the absolute values of the temperatures of each reactor is greater than or equal to a predetermined value, a temperature abnormality has occurred in any of the reactors To be judged. Thereby, temperature abnormality in a reactor can be judged more reliably.

  The temperature abnormality determination device according to the fifth aspect of the present invention is the temperature abnormality determination device according to any one of the first aspect to the fourth aspect, so that the temperature detection unit can detect the temperature of the core of each reactor. It is attached to the core of each reactor via an attachment member.

  In this temperature abnormality determination device, the temperature of the core of the reactor is used to determine the temperature abnormality of the reactor. Therefore, the reactor temperature abnormality can be accurately determined using the accurate reactor temperature.

  As described above, according to the present invention, the following effects can be obtained.

  According to the temperature abnormality determination device according to the first aspect of the present invention, it is possible to quickly determine that a temperature abnormality has occurred in any of the reactors, so that the abnormality causes an accident or failure. Can be prevented.

  According to the temperature abnormality determination device according to the second and third aspects of the present invention, it is possible to prevent a failure and an accident from occurring in a portion other than the reactor due to current concentration, and to ensure safety.

  According to the temperature abnormality determination device according to the fourth aspect of the present invention, it is possible to more reliably determine the temperature abnormality in the reactor.

  According to the temperature abnormality determination device according to the fifth aspect of the present invention, the reactor temperature abnormality can be accurately determined using the accurate reactor temperature.

The structure schematic of the air conditioning apparatus which concerns on this embodiment. 1 is a schematic configuration diagram of a compressor motor drive control device in which a temperature abnormality determination device according to an embodiment is employed. (A) The figure which shows schematically the side surface of the reactor to which the thermistor was attached. (B) The figure which shows schematically the upper surface of the reactor to which the thermistor was attached. The block diagram of the thermistor attachment member which concerns on this embodiment. The flowchart which shows the whole operation | movement of the motor drive control apparatus for compressors which concerns on this embodiment. The flowchart which shows the whole operation | movement of the motor drive control apparatus for compressors which concerns on a modification (A).

  Hereinafter, an embodiment of a temperature abnormality determination device according to the present invention will be described based on the drawings.

<Configuration>
-Air conditioner-
FIG. 1 is a schematic configuration diagram of an air conditioner 1 equipped with a compressor motor drive control device 42 in which a temperature abnormality determination device according to an embodiment of the present invention is employed. The air conditioner 1 in FIG. 1 is a so-called separate type air conditioner, and includes an indoor unit 3 and an outdoor unit 4. The indoor unit 3 and the outdoor unit 4 are connected by a refrigerant communication pipe, thereby forming a vapor compression refrigerant circuit 2 as shown in FIG. The refrigerant circuit 2 is filled with a CFC refrigerant such as R12, an HCFC refrigerant such as R22, an HFC refrigerant such as R410A, an HC refrigerant such as propane, carbon dioxide, ammonia, or the like.

  The indoor unit 3 is installed on the indoor ceiling, ceiling, wall surface, and the like, and mainly includes an indoor heat exchanger 31 and an indoor fan 32.

  The indoor heat exchanger 31 is an element constituting the refrigerant circuit 2. The indoor heat exchanger 31 functions as a refrigerant heater during the cooling operation to cool the indoor air RA, and functions as a refrigerant cooler during the heating operation to heat the indoor air RA. Specifically, the indoor heat exchanger 31 includes, for example, a fin-and-tube heat exchanger configured by a heat transfer tube through which a refrigerant flows and a large number of fins.

  The indoor fan 32 is a fan for sucking the indoor air RA into the indoor unit 3 and supplying the air (air supply SA in FIG. 1) after being sucked and heat-exchanged into the room. The indoor fan 32 is rotationally driven by an indoor fan motor (not shown).

  The outdoor unit 4 is installed outdoors, and mainly includes a compressor 41, a compressor motor drive control device 42, a four-way switching valve 43, an outdoor heat exchanger 44, an outdoor fan 45, and an expansion mechanism 46. The compressor 41, the four-way switching valve 43, the outdoor heat exchanger 44, and the expansion mechanism 46 are elements that constitute the refrigerant circuit 2, similarly to the indoor heat exchanger 31.

  The compressor 41 is a mechanism for compressing the refrigerant, and is a variable capacity compressor. Specifically, the compressor 41 is a so-called hermetic compressor in which a compressor motor 41a as a drive source is built. That is, in the compressor 41, the capacity of the compressor 41 can be varied by varying the rotation speed (that is, the operating frequency) of the compressor motor 41a. In this embodiment, the compressor 41 is a three-phase brushless DC motor.

  In particular, in the present embodiment, as the compressor 41, a compressor that is driven with a capacity equal to or greater than a predetermined capacity when the air conditioner 1 is operated is employed. That is, the capacity of the compressor 41 during operation is larger than that of the conventional compressor.

  The compressor motor drive control device 42 (that is, equivalent to a temperature abnormality determination device) is a device for driving and controlling the compressor motor 41a. The compressor motor drive control device 42 is electrically connected to the compressor motor 41a via wiring, and can output a drive voltage to the compressor motor 41a. The details of the compressor motor drive control device 42 will be described later.

  The four-way switching valve 43 is for switching the flow direction of the refrigerant. The four-way switching valve 43 causes the outdoor heat exchanger 44 to function as a cooler for the refrigerant compressed by the compressor 41 during the cooling operation, and the indoor heat exchanger 31 is used for the refrigerant cooled in the outdoor heat exchanger 44. In order to function as a heater, the discharge side of the compressor 41 and one end of the outdoor heat exchanger 44 are connected, and the suction side of the compressor 41 and one end of the indoor heat exchanger 31 are connected (four paths in FIG. 1). (Refer to the solid line of the switching valve 43). In addition, the four-way switching valve 43 causes the indoor heat exchanger 31 to function as a refrigerant cooler compressed by the compressor 41 and the outdoor heat exchanger 44 is cooled in the indoor heat exchanger 31 during the heating operation. In order to function as a refrigerant heater, the discharge side of the compressor 41 and one end of the indoor heat exchanger 31 are connected, and the suction side of the compressor 41 and one end of the outdoor heat exchanger 44 are connected (FIG. 1). (Refer to the broken line of the four-way selector valve 43).

  One end of the outdoor heat exchanger 44 is connected to the four-way switching valve 43, and the other end is connected to the expansion mechanism 46. The outdoor heat exchanger 44 functions as a refrigerant cooler using outdoor air as a heat source during cooling operation, and functions as a refrigerant heater using outdoor air as a heat source during heating operation. Specifically, as the outdoor heat exchanger 44, as with the indoor heat exchanger 31, for example, a fin-and-tube heat exchanger can be cited.

  The outdoor fan 45 is a fan for sucking the outdoor air OA into the outdoor unit 4 and exhausting the air (exhaust EA in FIG. 1) after being sucked and subjected to heat exchange. The outdoor fan 45 is rotationally driven by an outdoor fan motor (not shown).

  The expansion mechanism 46 is for depressurizing the high-pressure refrigerant. Examples of the expansion mechanism 46 include an electric expansion valve that depressurizes high-pressure refrigerant during cooling operation and heating operation.

-Motor drive controller for compressor-
Next, the configuration of the above-described compressor motor drive control device 42 (that is, equivalent to a temperature abnormality determination device) will be described in detail with reference to FIGS.

  The compressor motor drive control device 42 can control the drive of the compressor motor 41a, and determines temperature abnormalities in two reactors 52 and 53 (described later) provided in the control device 42. It is a device that can. Such a compressor motor drive control device 42 mainly includes a rectification unit 51, two reactors 52 and 53, two thermistors (corresponding to a temperature detection unit) 52a and 53a, a smoothing capacitor 54, and an inverter unit. 55 and a control unit 56.

  These functional units constituting the compressor motor drive control device 42 are mounted on one printed circuit board P1. The printed circuit board P1 is electrically connected to the three-phase commercial power supply 9 via the interfaces IF1, IF2, and IF3, and is electrically connected to the compressor motor 41a via the interfaces IF4, IF5, and IF6. Yes.

  The rectifying unit 51 is connected to the commercial power supply 9 via the interfaces IF1 to IF3, and is configured by connecting a plurality of diodes D1a, D1b, D1c, D1d, D1e, and D1f in a bridge shape. The rectification unit 51 rectifies an AC voltage from the commercial power supply 9 when input via the input units s1, s2, and s3.

  One end of each of the reactors 52 and 53 is connected to the cathode terminal side of the diodes D 1 a, D 1 c, and D 1 e of the rectifying unit 51, and the other end is connected to the plus side terminal pa of the smoothing capacitor 54. That is, the reactors 52 and 53 are connected to the rectifying unit 51 in parallel with each other on the power supply line L 1, connected to the subsequent stage of the rectifying unit 51 and the preceding stage of the smoothing capacitor 54.

  The thermistors 52a and 53a are for detecting the temperatures of the reactors 52 and 53, respectively, and are attached to the reactors 52 and 53 one by one. In particular, the thermistors 52a and 53a according to the present embodiment are connected to the reactors via the thermistor mounting members 7a and 7b (corresponding to the mounting members) so that the core temperatures Th1 and Th2 of the reactors 52 and 53 can be detected. It is attached to the cores 52 and 53 (see FIGS. 3A and 3B).

  Here, FIG. 3A is a schematic view when the reactors 52 and 53 to which the thermistors 52a and 53a are attached via the thermistor attachment members 7a and 7b are viewed from the side, and FIG. ) Shows a schematic diagram when the reactors 52 and 53 of FIG. As shown in FIGS. 3A and 3B, the thermistors 52a and 53a have the thermistor attachment members 7a and 7b attached to the side surfaces of the reactors 52 and 53, respectively. Specifically, the thermistor mounting members 7a and 7b are welded to the cores of the reactors 52 and 53 on the side surfaces of the reactors 52 and 53. The thermistors 52a and 53a are connected to the thermistor mounting members 7a and 7b with screws 8a, Screwed and fixed by 8b. In FIGS. 3A and 3B, the reference numerals of the thermistor 53a, the reactor 53, the thermistor mounting member 7b, and the screw 8b are shown in parentheses.

  The detailed structure of the thermistor mounting members 7a and 7b described above will be described later.

  The smoothing capacitor 54 is positioned after the rectifying unit 51 and the reactors 52 and 53, and the positive terminal pa is connected to the power supply line L1 and the negative terminal pb is connected to the GND line L2. The smoothing capacitor 54 smoothes the DC voltage that has been rectified by the rectifying unit 51. Such a smoothing capacitor 54 is composed of, for example, an electrolytic capacitor.

  The inverter unit 55 is connected to the subsequent stage of each of the reactors 52 and 53 and the smoothing capacitor 54 and is electrically connected to the compressor motor 41a via the interfaces IF4 to IF6. The inverter unit 55 generates a drive voltage for driving the compressor motor 41a using the rectified and smoothed DC voltage and outputs the drive voltage to the motor 41a. Such an inverter unit 55 includes a plurality of switching elements Q5a, Q5b, Q5c, Q5d, Q5e, Q5f and a plurality of freewheeling diodes D5a, D5b, D5c, D5d, D5e, D5f. It consists of and. The switching elements Q5a and Q5b, Q5c and Q5d, Q5e and Q5f are connected in series between the power supply line L1 and the GND line L2, and each connection of the switching elements Q5a and Q5b, Q5c and Q5d, Q5e and Q5f The points PU, PV, and PW are connected to the compressor motor 41a via the interfaces IF4 to IF6 on the printed circuit board P1. The free-wheeling diodes D5a to D5f have a characteristic of conducting when a reverse voltage is applied to the transistors Q5a to Q5f, and are connected in parallel to the transistors Q5a to Q5f.

  The control unit 56 is a microcomputer including a CPU and a memory, and is electrically connected to gate terminals of the switching elements Q5a to Q5f in the inverter unit 55. The control unit 56 controls the inverter unit 55, that is, controls on and off of the switching elements Q 5 a to Q 5 f in the inverter unit 55. In particular, the control unit 56 according to the present embodiment is also electrically connected to the thermistors 52a and 53a, and grasps the state of each reactor 52 and 53 and controls the inverter unit 55 based on the state. In order to perform such an operation, the control unit 56 functions as an abnormality determination unit 56a and an operation control unit 56b (corresponding to a first control unit).

-Abnormality judgment part-
The abnormality determination unit 56a subtracts the detection results of the thermistors 52a and 53a from each other to indicate the difference between the temperatures Th1 and Th2 of the reactors 52 and 53 (specifically, the temperatures of the cores of the reactors 52 and 53). The relative temperature ΔTd is calculated, and the temperature abnormality of the reactors 52 and 53 is determined based on the calculated reactor relative temperature ΔTd. Specifically, when the calculated reactor relative temperature ΔTd is equal to or greater than a predetermined difference ΔTx (ΔTd ≧ ΔTx), the abnormality determining unit 56a abnormally increases the temperature of one of the reactors 52 and 53. Judge that As described above, since the difference ΔTd between the core temperatures Th1 and Th2 of the reactors 52 and 53 is large, it is determined that current concentration occurs in one of the reactors 52 and 53 for some reason such as disconnection. Is possible.

  However, conversely, when the calculated reactor relative temperature ΔTd is smaller than the predetermined difference ΔTx (ΔTd <ΔTx), not only when the core temperatures of both reactors 52 and 53 are both normal, It is not unimaginable that the temperatures of the 53 cores are both abnormal. Therefore, the abnormality determination unit 56a further determines the temperature abnormality of the reactors 52 and 53 based on the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53, respectively. Specifically, the abnormality determination unit 56a monitors the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53, and if at least one of the absolute values is equal to or greater than the predetermined value Ty (| Th1 | ≧ Ty or | Th2 | ≧ Ty), it is determined that a temperature abnormality has occurred in the corresponding reactors 52 and 53. Conversely, when the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53 are both smaller than the predetermined value Ty (| Th1 | <Ty and | Th2 | <Ty), the core temperatures of the reactors 52 and 53 Is determined to be normal.

  Note that the above-described temperature abnormality determination is performed at predetermined time intervals determined in advance by, for example, desktop calculation, simulation, experiment, or the like. Further, the predetermined difference ΔTx and the predetermined value Ty are determined in advance by desktop calculations, simulations, experiments, etc., depending on the number of windings of the reactors 52 and 53 used, temperature characteristics based on the properties of the magnetic material, and the like.

  Here, in the present embodiment, the reason why the thermistors 52a and 53a detect the core temperatures Th1 and Th2 of the reactors 52 and 53 will be briefly described. The reactors 52 and 53 are constituted by a core and a winding wound around the core a plurality of times. When a current flows, the temperature of the winding increases in proportion to the square of the amount of current that flows. On the other hand, although the temperature of the core also rises due to the flowing current, the temperature rise rate is smaller than the temperature rise rate of the winding, so that there is a temperature difference between the winding and the core. Therefore, in the present embodiment, in order to accurately determine the temperature abnormality of the reactors 52 and 53, the core temperatures Th1 and Th2 of the reactors 52 and 53 are used instead of the winding temperature where the temperature rises rapidly. Therefore, the thermistors 52a and 53a detect the core temperatures Th1 and Th2 of the reactors 52 and 53, respectively.

-Operation control unit-
The operation control unit 56b controls the operation of the inverter unit 55 based on the result determined by the abnormality determination unit 56a. Specifically, when it is determined that a temperature abnormality has occurred in reactors 52 and 53, operation control unit 56b causes inverter unit 55 to turn off all switching elements Q5a to Q5f in inverter unit 55. Control. Thereby, the output of the drive voltage from the inverter unit 55 to the compressor motor 41a is stopped, and the compressor motor 41a stops rotating. Therefore, the compressor 41 stops operating.

  On the other hand, when it is determined that the reactors 52 and 53 are normal with no temperature abnormality, the operation control unit 56b causes the switching elements Q5a˜ to operate the compressor 41 at a desired capacity. Q5f is turned on and off. As a result, when there is no temperature abnormality in both reactors 52 and 53, the drive voltage is output from the inverter section 55 to the compressor motor 41a, and the compressor motor 41a rotates. Continues to work.

-Thermistor mounting member-
Next, the structure of the thermistor attachment members 7a and 7b (that is, attachment members) will be specifically described. FIG. 4 is a top view of the thermistor mounting members 7a and 7b and a side view seen from two directions. The thermistor mounting member 7a and the thermistor mounting member 7b have the same configuration, and in FIG. 4, the reference numerals for the thermistor mounting member 7b are shown in parentheses.

  The thermistor attachment members 7a and 7b are components for attaching the thermistors 52a and 53a, which are fixed to the thermistors 52a and 53a, to the reactors 52 and 53. The thermistor attachment members 7a and 7b include attachment member main bodies 71a and 71b and rotation stoppers 75a and 75b. Prepare.

  The attachment member main bodies 71a and 71b are fixed to the cores of the reactors 52 and 53 by welding. The attachment member main bodies 71a and 71b are plate-like members extending in a plate shape along the side surfaces of the reactors 52 and 53, and include first holes 72a and 72b and second holes (corresponding to screw holes) 73a and 73b. Is formed. The first holes 72a and 72b are holes for fixing the attachment member main bodies 71a and 71b to the cores of the reactors 52 and 53 by welding. The second holes 73a and 73b are screw holes for attaching the thermistors 52a and 53a to the attachment member main bodies 71a and 71b with the screws 8a and 8b shown in FIG. As an example of such attachment member main bodies 71a and 71b, the vertical width Wl can be about 10 mm, the horizontal width Wh can be about 30 mm, which is about three times the horizontal width Wl, and the material is a metal such as Fe or Al. Can be mentioned. In this case, the reactors 52 and 53 have a core width of about 10 mm or more, a temperature detection portion (hereinafter referred to as a head) of the thermistors 52a and 53a has a vertical width of about 5 mm, and a horizontal width of about 4 mm.

  The anti-rotation portions 75a and 75b are members for preventing the thermistors 52a and 53a from rotating with respect to the attachment member main bodies 71a and 71b, and in a direction crossing the surfaces from the surfaces of the attachment member main bodies 71a and 71b, specifically Is a protruding member protruding toward the thermistors 52a, 53a. Specifically, the rotation preventing portions 75a and 75b have a width of 3 mm and protrude from the attachment member main bodies 71a and 71b vertically by about 5 mm. The anti-rotation portions 75a and 75b are integrally formed with the attachment member main bodies 71a and 71b by a metal such as Fe or Al similar to the attachment member main bodies 71a and 71b. Such rotation stoppers 75a and 75b are wound around the thermistors 52a and 53a when the thermistors 52a and 53a are screwed to the attachment member bodies 71a and 71b fixed to the cores of the reactors 52 and 53, respectively. That is, when the thermistors 52a and 53a are screwed to the attachment member main bodies 71a and 71b, the rotation preventing portions 75a and 75b are arranged around the second holes 73a and 73b (specifically, the thermistors 52a and 53a are screw holes). The thermistors 52a and 53a are supported so as not to rotate in the direction of arrow A in FIG.

  The rotation preventing portions 75a and 75b allow the thermistors 52a and 53a to be securely attached at desired positions without being displaced from the core positions of the reactors 52 and 53 when the thermistors 52a and 53a are attached. In particular, as described above, if the vertical and horizontal widths of the heads of the thermistors 52a and 53a are about 5 mm and about 4 mm, respectively, and the core width of the reactors 52 and 53 is about 10 mm or more, the detent portion If the thermistors 52a and 53a are screwed without 75a and 75b, if the thermistors 52a and 53a rotate, for example, 45 degrees, the heads of the thermistors 52a and 53a may come off the core of the reactors 52 and 53 in some cases. . However, in the present embodiment, the thermistors 52a and 53a are prevented from rotating with respect to the mounting member main bodies 71a and 71b by the rotation preventing portions 75a and 75b, so that the thermistor corresponding to the core size of the reactors 52 and 53 is already described. Even if the heads 52a and 53a have a relatively small size, the thermistors 52a and 53a are surely attached near the cores of the reactors 52 and 53. Therefore, the thermistors 52a and 53a can reliably detect the core temperatures Th1 and Th2 of the reactors 52 and 53.

  The thermistors 52a and 53a are attached to the reactors 52 and 53. First, the thermistor attachment member bodies 71a and 71b to which the thermistors 52a and 53a are not attached are connected to the reactors 52 and 53 through the first holes 72a and 72b. The thermistor attachment members 7a and 7b are attached to the cores of the reactors 52 and 53. Next, when the thermistors 52a and 53a are aligned so as to be in a predetermined position, the thermistors 52a and 53a are prevented from rotating by the rotation preventing portions 75a and 75b, and then the screws 8a and 73a through the second holes 73a and 73b. It is screwed to the attachment member main bodies 71a and 71b by 8b.

  Temperatures Th1 and Th2 of the cores of the reactors 52 and 53 are transmitted to the thermistors 52a and 53a attached in this way in the order of the cores of the reactors 52 and 53, the thermistor attachment members 7a and 7b, and the thermistors 52a and 53a. Become.

  Further, as described above, in the present embodiment, the thermistor attachment members main bodies 71a and 71b are welded and attached to the cores of the reactors 52 and 53 via the first holes 72a and 72b. Can be easily joined to general reactors. Furthermore, by using welding as the joining means, it is possible to ensure the reliability of joining the thermistor mounting members 7a and 7b to the reactors 52 and 53.

<Operation>
FIG. 5 is a flowchart showing an overall operation flow of the compressor motor drive control device 42 according to the present embodiment.

  Steps S1 to S2: When the user gives an instruction to start operation of the air conditioner 1 via a remote controller (not shown) (Yes in S1), the various devices of the air conditioner 1 start operation. Specifically, the compressor motor drive control device 42 starts outputting the drive voltage to the compressor motor 41a (S2).

  Step S3: The thermistors 52a and 53a attached to the reactors 52 and 53 detect core temperatures Th1 and Th2 of the reactors 52 and 53, respectively. Then, the control unit 56 functioning as the abnormality determination unit 56a calculates the reactor relative temperature ΔTd from the core temperatures Th1 and Th2 of the reactors 52 and 53.

  Steps S4 to S6: When the reactor relative temperature ΔTd is greater than or equal to the predetermined difference ΔTx (Yes in S4, ΔTd ≧ ΔTx), or at least one of the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53 is the predetermined value Ty When the above is true (Yes in S5, | Th1 | ≧ Ty or | Th2 | ≧ Ty), the control unit 56 controls the inverter unit 55 to stop the output of the drive voltage to the compressor motor 41a. . Thereby, the compressor motor 41a stops rotating, and the operation of the compressor 41 stops (S6).

  When the reactor relative temperature ΔTd is smaller than the predetermined difference ΔTx (No in S4, ΔTd <ΔTx), and the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53 are both smaller than the predetermined value Ty (S5 No, | Th1 | <Ty and | Th2 | <Ty), since no temperature abnormality has occurred in the reactors 52 and 53, the inverter unit 55 continues to output the drive voltage to the compressor motor 41a.

  Step S7: Until the end of the operation of the air conditioner 1 is instructed (No in S7), the operations after Step S3 are repeated. When the end of the operation of the air conditioner 1 is instructed via a remote controller (not shown) (Yes in S7), the compressor motor drive control unit 42 ends the above-described series of operations, and the air conditioner The device 1 ends the operation.

<Features>
The compressor motor drive control device 42 according to the present embodiment has the following characteristics.

(1)
In the compressor motor drive control device 42, in the state where the plurality of reactors 52 and 53 are connected in parallel to each other, the temperature abnormality of the reactors 52 and 53 is determined based on the relative temperature ΔTd of the reactors 52 and 53. For example, when the relative temperature ΔTd of the reactors 52 and 53 is equal to or greater than a predetermined difference ΔTx, it is determined that the temperature in any of the reactors 52 and 53 is abnormal. Thus, by using the relative temperature ΔTd of the reactors 52 and 53, it is possible to quickly determine that a temperature abnormality has occurred in any of the reactors 52 and 53. Therefore, it is possible to prevent an accident or failure from occurring due to a temperature abnormality in one of the reactors 52 and 53.

(2)
In the compressor motor drive control device 42, when the temperature is determined to be abnormal in any of the reactors 52 and 53, the output of the drive voltage to the compressor motor 41a by the inverter unit 55 is stopped. The That is, when there is a temperature abnormality in one of the reactors 52 and 53, the compressor motor 41a stops rotating, and therefore, it is possible to prevent a failure and an accident from occurring in parts other than the reactors 52 and 53 due to current concentration. Can be secured.

(3)
In the compressor motor drive control device 42, the reactor relative temperature ΔTd is equal to or greater than a predetermined difference ΔTx (ΔTd ≧ ΔTx), or at least one of the absolute values of the core temperatures Th1 and Th2 of the reactors 52 and 53 is predetermined. If the value is equal to or greater than the value Ty (| Th1 | ≧ Ty, | Th2 | ≧ Ty), it is determined that a temperature abnormality has occurred in any of the reactors 52 and 53. Thereby, the temperature abnormality in the reactors 52 and 53 can be determined more reliably.

(4)
In particular, in the present embodiment, the core temperatures Th1 and Th2 of the reactors 52 and 53 are used for determining the temperature abnormality of the reactors 52 and 53. Therefore, the temperature abnormality of the reactors 52 and 53 can be accurately determined using the accurate temperatures of the reactors 52 and 53.

  In the present embodiment, a compressor 41 having a relatively large capacity is used, and the compressor motor drive control device 42 is used for driving a compressor motor 41a that is a drive source of the compressor 41. Yes. Thus, if the capacity of the compressor 41 is relatively large, the capacity becomes insufficient with one reactor. Therefore, in the compressor motor drive controller 42, a plurality of reactors 52 and 53 are connected in parallel. Then, current concentration occurs in any of the reactors 52 and 53, and there is a possibility that an abnormal temperature rise may occur. However, in this compressor motor drive control device 42, since the temperature abnormality of the reactors 52 and 53 is detected based on the relative temperature ΔTd of each reactor 52 and 53, a plurality of reactors 52 and 53 must be connected in parallel. In the case where it cannot be obtained, the temperature abnormality of the reactors 52 and 53 can be quickly determined.

  In the present embodiment, the thermistors 52a and 53a are fixed to the reactors 52 and 53 via the thermistor mounting members 7a and 7b. Specifically, the thermistors 52a and 53a are screwed to the reactors 52 and 53 in a state where the thermistors 52a and 53a are fixed to the attachment member main bodies 71a and 71b by the rotation preventing portions 75a and 75b. Therefore, when the thermistors 52a and 53a are screwed to the attachment member main bodies 71a and 71b fixed to the reactors 52 and 53, the thermistors 52a and 53a are not displaced from the cores of the reactors 52 and 53, and are desired. Attach to position. Accordingly, the thermistors 52a and 53a can accurately measure the core temperatures Th1 and Th2 of the reactors 52 and 53.

<Modification of Compressor Motor Drive Control Device According to this Embodiment>
(A)
In the above description, the operation of the compressor 41 is stopped when it is determined that a temperature abnormality has occurred in the reactors 52 and 53 as shown in step S6 of FIG. However, when it is determined that a temperature abnormality has occurred in the reactors 52 and 53, the operation of the compressor 41 is not stopped, but the capacity of the compressor 41 is low as shown in step S16 of FIG. Inverter part 55 may be controlled so that it may become. That is, in this case, the control unit 56 (corresponding to the second control unit) functioning as the operation control unit 56b is a drive voltage for reducing the rotational speed of the compressor motor 41a so that the capacity of the compressor 41 is reduced. Is output from the inverter unit 55 to the compressor motor 41a. Thereby, it can prevent that a failure and an accident arise in parts other than the reactors 52 and 53 by current concentration, and can ensure safety.

  6 is the same as FIG. 5 except that the content of step S16 is different from the content of step S6 of FIG. That is, steps S11 to S15 and S17 in FIG. 6 are the same as steps S1 to 5 and S7 in FIG. Therefore, description of steps other than step S16 according to FIG. 6 is omitted.

(B)
In the above description, the case where the number of the reactors 52 and 53 connected in parallel with each other in the compressor motor drive control device 42 is two has been described. However, in the present invention, the number of reactors connected in parallel to each other only needs to be two or more, and is not limited to two.

(C)
In the above description, the thermistor attachment members 7a and 7b have been described as being used as members for attaching the thermistors 52a and 53a to the reactors 52 and 53. However, the use of the thermistor mounting members 7a and 7b is not limited to the reactor. The thermistor attachment member can be used when attaching a thermistor that detects the temperature of the core to a coil having the core. Therefore, if the core is provided, the thermistor mounting member according to the present invention can be applied to a transformer for mounting a thermistor for detecting the temperature of the core.

  By using the present invention, in an inverter circuit in which a plurality of reactors are connected in parallel, it is possible to quickly determine that a temperature abnormality has occurred in any one of the reactors. Accidents and breakdowns can be prevented.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Refrigerant circuit 3 Indoor unit 4 Outdoor unit 7a, 7b Thermistor attachment member 41 Compressor 41a Compressor motor 42 Compressor motor drive control device 51 Rectifier 52, 53 Reactor 52a, 53a Thermistor 54 Smoothing capacitor 55 Inverter Part 56 control part 56a abnormality judgment part 56b operation control part 71a, 71b attachment member main body 73a, 73b second hole 75a, 75b detent part

Japanese Patent Laid-Open No. 5-15169

Claims (5)

A rectifying unit (51) for rectifying an AC power supply;
An inverter unit (55) for generating a drive voltage for driving the motor (41a) using the power supply after rectification and outputting the drive voltage to the motor;
A plurality of reactors (52, 53) connected in parallel between the rectifying unit (51) and the inverter unit (55);
A temperature detector (52a, 53a) for detecting the temperature of each of the reactors;
An abnormality determination unit (56a) for determining an abnormality in the temperature of the reactor based on a reactor relative temperature indicating a difference in temperature between the reactors;
A temperature abnormality determination device (42). A first control unit (56b) for controlling the inverter unit so that the inverter unit stops outputting the drive voltage when the abnormality determination unit determines that a temperature abnormality has occurred in the reactor;
The temperature abnormality determination device (42) according to claim 1, further comprising: The motor (41a) is a compressor motor which is a drive source of a variable capacity compressor,
A second control unit (56b) for controlling the inverter unit such that the capacity of the compressor is reduced when the abnormality determination unit determines that a temperature abnormality has occurred in the reactor;
The temperature abnormality determination device (42) according to claim 1, further comprising: The abnormality determination unit (56a)
Furthermore, it is possible to determine the temperature abnormality of the reactor based on the absolute value of the temperature of each reactor,
When the reactor relative temperature is greater than or equal to a predetermined difference, or when at least one of the absolute values of the temperature of each of the reactors is greater than or equal to a predetermined value, it is determined that there is the reactor having a temperature abnormality.
The temperature abnormality determination apparatus (42) according to any one of claims 1 to 3. The temperature detectors (52a, 53a) are attached to the cores of the reactors via attachment members (7a, 7b) so that the temperature of the cores of the reactors can be detected.
The temperature abnormality determination apparatus (42) according to any one of claims 1 to 4.

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