JP2015072088A - Compressor motor control device for cooling machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor motor control device for a cooling machine that effectively utilizes limited temperature information and can reflect the information to rotational frequency setting.SOLUTION: In rotational frequency setting processing R101 at a steady time, a plurality of pieces of threshold information is set. Consequently, a plurality of comparison results between a parameter tins (6) and a threshold are obtained. Then, when a measured total period tins (6) reaches either one (or both) of the thresholds, the rotational frequency setting processing is transitioned to processing S121, and a setting rotational frequency is shifted up by one stage. In this embodiment, by using threshold information having different natures, multiple analysis can be performed to one parameter, and an optimal setting of the setting rotational frequency can be attained.

Description

  The present invention relates to a compressor motor control device for a chiller, and is particularly suitable for use in setting the number of rotations of a compressor motor.

  In recent years, electronic thermostats have been used in the technical field of refrigerators and refrigerators in order to achieve fine control of the internal temperature. Here, the electronic thermostat can detect and notify more temperature information than two points, and is useful for a variable speed type apparatus using a DC brushless motor. On the other hand, the mechanical thermostat performs a simple operation to detect and notify only the upper limit temperature and the lower limit temperature in the cabinet, and is a device that determines the rotation speed of the compressor motor fixedly by AC input (not possible). Have been used for a long time.

  For example, in Japanese Patent Laid-Open No. 2013-060907 (Patent Document 1), a mismatch between a mechanical thermostat and a variable speed control device is pointed out. As a technique for improving this, a set rotation based on a load current is proposed. The number is rising.

JP 2013-060907 A

  However, according to the technique of Patent Document 1, since only one threshold value information is provided in order to obtain one determination result when setting the number of revolutions, a physical phenomenon is grasped from various directions and applied to the determination logic. I can't. In particular, when the rotational speed is set using a mechanical thermostat, the input temperature information is limited. Therefore, in the control device for setting the rotational speed, the limited temperature information is effectively utilized, An advanced operation for selecting the optimum set rotational speed is required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a compressor motor control device for a cooler that can effectively utilize limited temperature information and reflect it in the rotation speed setting.

In order to solve the above problems, the present invention has the following configuration of a compressor motor control device for a cooling machine. That is, in a compressor motor control device for a cooler comprising a rotation speed setting process for automatically changing the rotation speed of a compressor motor based on the passage of time,
The rotation speed setting process automatically changes the set rotation speed if the measured period has reached at least one of the comparison results with a plurality of threshold values that are determination criteria for the passage of the period. And

  Preferably, the plurality of threshold values include a first threshold value representing a fixed time or period and a second threshold value representing a variable time or period.

  Preferably, the second threshold value is a threshold value representing an ON operation period or an OFF operation period of the compressor motor.

  According to the compressor motor control device for a chiller according to the present invention, a plurality of threshold information is set for one parameter created based on limited temperature information. It is possible to realize the optimum setting of the set rotational speed.

The figure which shows the circuit structure of the compressor motor control apparatus for refrigerators which concerns on embodiment. The figure which shows the time chart of the various states which concern on embodiment. 3 is a time chart of an IPD operation period according to the first embodiment. The figure which shows the rotation speed setting process and mode selection process of an IPD driving | operation period which concern on Example 1. FIG. The figure which shows the rotation speed setting process of the IPD driving | operation period which concerns on Example 2. FIG. 10 is a time chart of an IPD operation period according to the second embodiment. The figure which shows the rotation speed setting process of the steady operation period which concerns on Example 3. FIG. The figure which shows the mode selection process of the steady operation period which concerns on Example 4. FIG. The figure which shows the mode selection process of the steady operation period which concerns on Example 4. FIG. FIG. 10 is a diagram illustrating priority selection result setting processing according to an eighth embodiment. 10 is a time chart of a steady operation period according to the fifth embodiment. The figure which shows the rotation speed setting process of the steady operation period which concerns on Example 5. FIG. The figure which shows the rotation speed setting process of the steady operation period which concerns on Example 6. FIG. The figure which shows the rotation speed setting process of the steady operation period which concerns on Example 6. FIG. The figure which shows the mode selection process of the steady operation period which concerns on Example 7. FIG. The figure which shows the mode selection process of the steady operation period which concerns on Example 7. FIG. FIG. 10 is a diagram illustrating priority selection result setting processing according to an eighth embodiment.

  Hereinafter, embodiments and the like (Examples 1 to 8) according to the present invention will be specifically described with reference to the drawings. Note that the embodiments and Examples 1 to 8 have contents related to each other, and the already described items are denoted by the same reference numerals in order to avoid redundant description, and description thereof is omitted.

  FIG. 1 shows a circuit configuration of a compressor motor control device for a cooler according to the present embodiment. Compressor compressor motor control device 100 (hereinafter referred to as a motor control device) includes a power conversion circuit 120 and a control circuit 150.

  Among these, the power conversion circuit 120 receives AC power from one side and supplies a three-phase current obtained by converting the AC power to the DC brushless motor 140 (hereinafter referred to as a compressor motor) on the other side. The power conversion circuit 120 includes a rectifier circuit, a PFC circuit, and an inverter circuit. A current pattern flowing through the compressor motor 140 is determined by the inverter circuit, and the rotor is driven by the current pattern.

  The compressor motor 140 forms a refrigerant circuit (not shown) together with the outdoor unit, capillary tube, and evaporator (not shown). By increasing or decreasing the number of rotations of the compressor motor 140, the endothermic effect on the internal heat load is increased. Let them adjust. Hereinafter, the rotational speed commanded by the control circuit 150 is referred to as a set rotational speed.

  The control circuit 150 is connected to the mechanical thermostat 170 via the signal line 180. Further, it is connected to a power transistor of the power conversion circuit 120 via a plurality of signal lines 160. This control circuit incorporates a CPU, an AD conversion circuit, a memory circuit, a clock circuit, etc., performs an appropriate operation based on predetermined information, and outputs the result information / signal to the memory circuit or the outside. .

  In particular, in the memory circuit, a control program, parameter information, and the like are recorded in an appropriate storage area, and the CPU appropriately acquires this information and executes processing operations in the sequence of the program. In the memory circuit according to the present embodiment, PWM signal generation processing, motor on / off determination processing, rotation speed setting processing R100, mode selection recording processing R200, program related to composite routine R300, time threshold information, and the like are recorded. Yes. In the control circuit 150, function construction is performed in cooperation with these programs, and appropriate processing is performed. For example, the motor on / off determination process determines whether to switch the compressor motor to an on operation or to an off operation based on a signal from a mechanical thermostat. The PWM signal generation process generates a DUTY PWM signal calculated based on the set rotational speed.

  The mechanical thermostat 170 detects the upper limit temperature Th1 and the lower limit temperature Th2 to be inspected, converts them into electrical signals, and outputs them. This mechanical thermostat 170 is installed in the refrigerator-freezer, and the internal temperature is a detection target. As described above, the mechanical thermostat 170 used in the present embodiment is a thermostat widely used in non-variable speed devices that operate an AC motor at a fixed rotational speed, and changes from an upper limit temperature Th1 to a lower limit temperature Th2. It is not possible to detect the temperature along the way. That is, this mechanical thermostat 170 is a simple one that reports temperature information at only two points.

  Therefore, since the motor control device 150 according to the present embodiment cannot obtain intermediate temperature information from the upper limit temperature Th1 to the lower limit temperature Th2, the set rotation speed of the compressor motor can be automatically changed during this period. The following measures are taken.

  FIG. 2 shows various states related to the operation of the compressor motor. First, the operating state of the compressor motor is determined by whether or not a current for driving the compressor motor 140 is flowing, and this is related to the output signal of the mechanical thermostat 170.

  That is, when the signal indicating that the mechanical thermostat 170 has reached the upper limit temperature Th1 (hereinafter referred to as the upper limit signal) is output, the control device 150 turns on the compressor motor 140 based on this signal and starts cooling the inside of the cabinet. Let On the other hand, when the mechanical thermostat 170 outputs a signal indicating that the lower limit temperature Th2 has been reached (hereinafter referred to as a lower limit signal), the control device 150 turns off the compressor motor 140 based on this signal. Therefore, in a scene where the change from “Th1 to Th2” occurs, the compressor motor 140 is in a driving state, which is referred to as an “on operation period”. Further, in a scene where “Th2 → Th1” is changed, the compressor motor 140 is stopped, which is referred to as an “off operation period”. A set of the first on-operation period and the off-operation period is referred to as STEP (1), and a set of the N-th on-operation period and the off-operation period is referred to as STEP (N).

  The set rotational speed ωp is implemented in the rotational speed setting process. In this process, a starting rotational speed ωa set to a constant rotational speed and a changed rotational speed ωb that sequentially changes the rotational speed are prepared. Has been. Among these, the starting rotational speed ωa is set by the starting rotational speed setting process. The changed rotational speed ωb is a rotational speed that is set after the start rotational speed ωa is up, and is set in the changed rotational speed setting process. For STEP (1), the IPD state detection rotational speed ωi is set prior to the starting rotational speed ωa.

  In the changed rotation speed setting process, an operation of increasing and decreasing in a stepwise and automatic manner is sequentially performed every time the specified rotation speed is increased. That is, the changed rotation speed setting process realizes an operation for shifting the set rotation speed for each specified period and an operation for performing the shift operation a plurality of times.

  An operation mode in which the changed rotational speed ωb increases with respect to the starting rotational speed ωa, or an operating mode in which the changed rotational speed ωb itself increases, and these are collectively referred to as a rising mode. On the other hand, an operation mode in which the changed rotational speed ωb decreases with respect to the starting rotational speed ωa, or an operating mode in which the changed rotational speed ωb itself decreases, these are collectively referred to as a descending mode. Such mode setting is performed by mode selection processing and selection result priority setting processing described later.

  Since the rotational speed setting process includes a starting rotational speed setting process and a changed rotational speed setting process, the set rotational speed of the compressor motor 140 is automatically changed over time. Accordingly, the set rotational speed ωp in the ON operation period is appropriately changed according to the arrival of the specified period, as shown in FIG. Here, the specified period refers to a period in which the engine is operated at one set rotational speed, and according to STEP (1) in the figure, each of t1 to t1v, t1v to t1w, t1w to t1x, t1x to t1c, Point to. More specifically, one set rotational speed is given to each of the IPD state detection rotational speed ωi and the starting rotational speed ωa. On the other hand, with respect to the changed rotation speed ωb, one set rotation speed is given in correspondence with one set period, and a plurality of set rotation speeds are prepared as a whole.

  Further, the specified period is set in advance by the rotation speed setting process. For example, in STEP (1), “t1 to t1v” is defined as a specified period corresponding to the starting rotational speed ωa, and is set to 30 [min] in the present embodiment. In STEP (1), each of “t1v to t1w, t1w to t1x, and t1x to t1c” is defined as a specified period corresponding to the changed rotational speed ωb. 15 [min]. Also, the above-mentioned specified period is specified in advance for STEP (N) to STEP (N + 2). However, in STEP (N + 1), since the internal temperature has reached the upper limit temperature Th1 before switching to the changed rotational speed, the operation at the prepared changed rotational speed ωb is not performed.

  As described above, in the rotation speed setting process according to the present embodiment, since a plurality of set rotation speeds are prepared for each specified period, the set rotation speed is changed a plurality of times every time this specified period arrives. . In other words, according to the motor control apparatus 100 according to the present embodiment, a plurality of set rotation speeds are prepared to enable stepwise rotation speed setting, and the internal temperature can be finely adjusted without using an electronic thermostat. Realization of low-cost control.

  Further, in the rotation speed setting process, since the determination logic for the set rotation speed is constructed only by the parameter of the specified period, the determination logic can be simplified. In addition, it is not necessary to provide a new circuit configuration for obtaining parameters during the specified period.

  Further, in the changed rotational speed setting process according to the present embodiment, the difference Δω before and after switching the set rotational speed is set as 500 [rpm] in the ascending mode, and set as 100 [rpm] in the descending mode. Has been. That is, the setting range for increasing the set rotational speed in steps (Δω in the ascending mode) is set to be larger than the setting range for decreasing the rotational speed in steps (Δω in the descending mode).

  As described above, in the present embodiment, since the mechanical thermostat 170 is used, an intermediate temperature other than the upper limit temperature and the lower limit temperature cannot be detected. For this reason, it is difficult to detect the fluctuation of the thermal load at the intermediate timing. In addition, in the system using the mechanical thermostat 170, only information on the upper limit temperature and the lower limit temperature can be obtained, so it is difficult to appropriately adjust the set rotational speed by grasping the circulation state of the cold air.

  Therefore, in this embodiment, by setting Δω in the ascending mode large, priority is given to the cooling action of the internal temperature, and the food group stored in the internal space is preserved. On the other hand, in the descending mode, since the fluctuation of the heat load or the like cannot be grasped, the set value Δω is made small so that the heat absorption amount due to the cooling action does not fall below the heat amount of the heat load.

  As described above, in the present embodiment, even if the state of the heat load / leakage cannot be grasped, a device that does not greatly deviate from the preferred setting rotational speed is provided by changing the changing speed of the setting rotational speed in accordance with each mode. ing.

  In the present embodiment, when the internal temperature reaches the lower limit temperature Th2, the lower limit signal is received from the mechanical thermostat 170, and the compressor motor 140 is stopped. In the off operation period, information related to the measured value of the driving operation period and the set rotational speed set immediately before the stop operation is recorded in the memory circuit. Further, a mode setting process described later is executed based on these pieces of information.

  Hereinafter, further features of the present embodiment will be described in detail with reference to Examples 1 to 7. As described above, the technique of each example uses the technique of the present embodiment, and the description of the overlapping part is omitted. Further, the relationship between the embodiments also includes matters common to each other except for the changed portions.

  In the present embodiment, the rotation speed setting during the IPD operation will be described with reference to FIGS. 3 and 4A. Here, the IPD operation (Initial Pull Down) is a control temperature (for example, “−15 ° C. to −18 ° C.” in a freezer room, “5 ° C. to 3 ° C.” in a refrigerator room). ), For example, a control process from when the internal temperature starts operation from the outside air temperature state to the steady operation. In addition, the steady operation refers to an operation in which the internal temperature is hysteresis controlled before and after the above-described scheduled control temperature.

  FIG. 3 shows the control state of the compressor motor during the IPD operation period, that is, STEP (1). As the rotation speed of the compressor motor in such a scene, first, the IPD state detection rotation speed ωi is set, and then the set rotation speed ωp that automatically increases stepwise is set. These set rotation speeds are set by the IPD operation rotation speed setting process.

  The IPD state detection rotational speed ωi is set by the inspection rotational speed setting process, and is set first among a series of set rotational speeds set in the IPD operation period. On the other hand, the set rotational speed ωp is set by the rotational speed setting process, and immediately after the IPD state detection rotational speed ωi, that is, immediately after the expiration of the specified period of the IPD state detection rotational speed ωi. The number of rotations to be set.

  Both the IPD state detection rotational speed ωi and the set rotational speed ωp belong to the set rotational speed given by the IPD operation rotational speed setting process. However, the latter setting is used so that the set rotational speed when the both are collectively referred to in the IPD operation rotational speed setting process and the set rotational speed ωp in the rotational speed setting process in the IPD operational rotational speed setting process can be distinguished and understood. Hereinafter, the rotational speed ωp will be referred to as a rising set rotational speed ωp. The process for setting the set rotational speed ωp is also referred to as a rising rotational speed setting process.

  FIG. 4A shows a flowchart regarding the IPD operation rotation speed setting process. The process R100 is activated by turning on the power to the refrigerator-freezer. According to the process R100, first, the inspection rotational speed setting process S101 is executed, and the operation of the compressor motor is started at the IPD state detection rotational speed ωi. Further, not limited to this, when there is no history of operation information remaining in the memory circuit, it is highly likely that it is immediately after the power is turned on. Therefore, the IPD operation rotation speed setting process R100 is performed based on this. Also good. Further, when the history of transition to steady operation is not left as the latest information, the IPD operation rotation speed setting process R100 may be performed based on this information.

  When the process S101 is completed, a change mode setting process S102 is executed, and a change mode for increasing the rotation speed at every change timing of the set rotation speed, that is, an increase mode is set. This is a mode given as a default for the IPD operation rotation speed setting process R100.

  Thereafter, in the first operation time measurement process S103, the total time tins (1) of the IPD operation setting rotational speed is measured, and it is determined at every predetermined time whether or not the specified period t (th1) has been exceeded. Is done. Then, when the total time tins (1) reaches the specified period t (th1), the process proceeds to processing S105. In this embodiment, the specified period t (th1) is set to 30 [min].

  At this time, in the temperature information monitoring process S104, while the process S103 measures the total time tins (1), it is determined whether or not the internal temperature has reached the lower limit temperature Th2 (the temperature that is the basis of the OFF command information). When monitoring and receiving this OFF command information, the operation of the compressor motor is stopped (S110), and the operation information during this period, that is, the ON operation period information Δtc1 and the final set rotational speed information ωrec1 are recorded in the memory circuit ( S111). Here, the final set rotation speed indicates the set rotation speed immediately before the operation is stopped.

  In general, when the compressor motor is quickly stopped at the IPD state detection rotational speed ωi, the chamber temperature is cooled to such an extent that the IPD operation is not required, or the state has already shifted to the steady operation. It is believed that there is. On the other hand, when the total period tins (1) of the IPD state detection rotational speed ωi exceeds the specified period t (th1), it has been confirmed that the IPD operation rotational speed setting process has been activated. Therefore, in this case, it is preferable to shift to the main IPD operation, that is, the ascending rotational speed setting process described below. In the present embodiment, this technical situation is utilized, and the specified period t (th1) is set as an appropriate value for distinguishing these.

  Therefore, according to the present embodiment, the motor control device 100 can determine whether or not the IPD operation is necessary based on the specified period t (th1) without grasping the temperature state above the upper limit temperature Th1. It becomes.

  As described above, when the total period tins (1) in the scene set to the IPD state detection rotational speed ωi is up, the ascending rotational speed setting process functions. Here, the ascending rotation speed setting process includes processes S105 to S108. Among these, the first switching rotation speed setting process S105 gives a set rotation speed immediately after the IPD state detection rotation speed ωi, and operates the compressor motor at the above-described start rotation speed ωa.

  The starting rotational speed ωa is determined in the second operation time measurement process S106 whether or not the total time tins (2) has reached the specified period t (th2). The specified period t (th2) given as the threshold value of the rotational speed ωa is set to 15 [min].

  While the process S106 is in progress, the time-up of the total period tins (2) is monitored, and at the same time, it is also monitored whether the internal temperature has reached the lower limit temperature Th2 (S107). If the internal temperature reaches the lower limit temperature Th2, the compressor motor is stopped S110, and predetermined operation information is recorded in the memory circuit (S111).

  On the other hand, when the total time tins (2) for the starting rotational speed ωa reaches the specified period t (th2), the changed rotational speed ωb is set by the second switching rotational speed setting process S108. When the time for the total period of the changed rotational speed ωb is up, the engine speed is switched to a higher rotational speed. In addition, as for starting rotation speed (omega) a and change rotation speed (omega) b which concerns on a present Example, the raise setting range (DELTA) omega is set to 500 [rpm].

  In the present embodiment, the stepwise increase in the changed rotational speed ωb is repeated with 4500 [rpm] as the upper limit. Hereinafter, the upper limit set rotational speed will be referred to as the maximum change rotational speed ωbh. Thus, according to the present embodiment, consideration is given to not deteriorating the COP value by setting the upper limit value for the changed rotational speed ωb.

  In this embodiment, the internal temperature reaches the lower limit temperature Th2 at some timing in the process so far, the compressor motor is stopped by this information (S110), and the operation information grasped in STEP (1) is obtained. Recording is performed (S111), and the IPD operation rotation speed setting process shifts to the sleep state.

  Here, the operation information may be provided with on-operation period information Δtc1, final set rotation speed information ωrec1, and history information on completion of IPD operation. Further, the final set rotational speed information ωrec1 in the present embodiment indicates the rotational speed that has been set until immediately before time t1c. Further, mode information described later is also included in this operation information.

  As described above, according to the IPD operation rotation speed setting process according to the present embodiment, the specified period t (th1) given to the IPD state detection rotation speed ωi is the regulation given to each of the automatically set rotation speeds ωp. The period is longer than the period t (th2). According to this, even if the cooling gradient of the internal temperature is somewhat slow, it becomes easy to obtain information that is valuable to the system (information that the lower limit temperature Th2 has been reached). Therefore, in the present system in which the rotation speed is set based on a small amount of temperature information, the rate of change in the internal temperature is grasped based on this information, and the necessity of IPD operation is properly determined.

  The IPD state detection rotational speed ωi is preferably set in a range of “1500 [rpm] ≦ ωi ≦ 3000 [rpm]”. According to this, the IPD state detection rotational speed ωi can avoid the redundancy of the IPD operation operation period compared to the case where the cooling action is extremely reduced, and STEP (1 ) To suppress the increase in COP value.

  In addition, the operation speed by the emergency setting rotation speed is provided for the setting rotation speed of a compressor motor as fail safe in an emergency. The emergency set rotational speed is set to a rotational speed at which the internal temperature cannot be sufficiently cooled, for example, about 1200 [rpm]. When such a rotational speed is set, the refrigerator / freezer cannot sufficiently exhibit the cooling action, and it is difficult to acquire valuable information indicating the cooling gradient (information indicating that the lower limit temperature Th2 has been reached). In addition, when the speed is increased step by step from the low speed, the number of increases in the set rotational speed must be increased. As a result, the IPD operation period is prolonged. Therefore, in this embodiment, the value is set to a value sufficiently larger than the emergency set rotational speed so that the IPD detection rotational speed ωi quickly reaches the appropriate rotational speed.

  The present embodiment is a technique relating to the rotational speed setting during the IPD operation, and is a modification of the first embodiment described above. Hereinafter, a description will be given with reference to FIGS. 5 and 6. First, FIG. 5 shows a flowchart of the IPD operation rotation speed setting process according to the present embodiment. The process R100 is additionally configured with a rotation speed increase possibility determination process S112 and a third switching rotation speed setting process S113.

  As a premise of the description, it is assumed that the ascending rotation speed setting process is performed in a scene where the maximum change rotation speed ωbh (4500 [rpm] in this embodiment) is set. In this scene, when it is confirmed that the total period tins (2) of the rotational speed ωbh has reached the specified period t (th2) (S106), the rotational speed increase possibility determination process S112 functions, and the further increase of the rotational speed is performed. Determine whether it is possible. However, in this scene, since the set rotational speed cannot be increased from this, the third switching rotational speed setting process S113 functions, and the set rotational speed is set to a lower rotational speed than the on-site surface.

  Usually, in a situation where the internal temperature is not cooled even if the set rotational speed is sufficiently increased, it is considered that the cause is a mismatch between the heat load and the cooling capacity, a lack of refrigerant, or the like. However, since there is a possibility that an unexpected and serious failure may be caused, in this embodiment, the set rotational speed is lowered as an operation to avoid this.

  The set rotational speed of such a scene is preferably set to be lower than the IPD state detection rotational speed ωi. In the first place, the IPD state detection rotational speed ωi is intended to “acquire information indicating that the lower limit temperature Th2 has been reached”, but is not familiar with the rotational speed provided as fail-safe. That is, the reason why the process S113 according to the present embodiment selects such a set rotational speed is to prevent deterioration of the failure part and give priority to avoiding the accident, and the compressor is within a range in which this can be protected. The idea is to drive the motor.

  For this reason, it is desirable that the rotation speed set in step S113 is 1500 [rpm] or less, and according to this embodiment, the set rotation speed is 1200 [rpm], that is, the emergency setting rotation speed. Set to According to this, it does not impose a significant load on the compressor motor and contributes to delaying the quality deterioration of the stored product by suppressing the rise of the internal temperature to some extent.

  In this embodiment, the setting of the number of rotations during steady operation will be described. FIG. 7 shows a rotational speed setting process according to this embodiment, that is, a steady-state rotational speed setting process R100. The constant rotation speed setting process R100 is started every time the ON operation is restarted, and this operation is repeated for a period controlled by steady operation.

  When the process R100 is activated, first, the first driving information recording process S111a is performed. In the processing S111a, information in which the immediately preceding off operation period is recorded (hereinafter referred to as off operation period information Δts) is recorded in the memory circuit. This “first driving information” is information belonging to the driving information described above, and is used when mode setting described later.

  When the process S111a is completed, a starting rotational speed setting process S101 is executed. This process S101 determines the starting rotational speed ωa of the set rotational speed ωp, and operates the compressor motor at the rotational speed ωa. In the process S101 in this embodiment, the latest final set speed information ωrec is extracted from the operation information recorded in the memory circuit, and the compressor motor is operated with this value as the set value of the start speed ωa. Therefore, in the process S101, if the immediately preceding final set rotational speed information ωrec is appropriate, the starting rotational speed ωa matches the rotational speed information ωrec.

  When the process S101 is completed, a change mode setting process S102 is executed. However, in the processing S102 according to the present embodiment, unlike the processing S102 in the IPD operation, it is determined by the predetermined determination logic whether the rising mode or the falling mode is set. The determination logic relating to mode setting will be described in detail later.

  In the present embodiment, after the process S102, the fourth operation time measurement process S114 is executed. In the process S114, the total period tins (4) for the starting rotational speed ωa or the changed rotational speed ωb is measured. In the process S114, a specified period t (th4) as a comparison reference is set, and the total period tins (4) and the specified period t (th4) are compared. Here, it is assumed that the reference period t (th4) is set to 15 [min].

  Here, when the total period t (th4) reaches the specified period t (th4), the predetermined setting width Δω is added or subtracted by the fourth switching rotation speed setting process S115, and the process S114 is executed again. More specifically, in step S115, when the ascending mode is set, a set width Δω1 (for example, Δω1 = 500 rpm) is added to the set rotation speed ωp. Further, when the descending mode is set, a set width Δω2 (for example, Δω2 = 100 rpm) is subtracted from the set rotation speed ωp. In other words, in this embodiment, operations such as shifting up or down the set rotational speed are repeated every 15 [min].

  Further, the temperature information monitoring process S107 determines whether the internal temperature has decreased to the lower limit temperature Tth2 in parallel with the time check in the process S114. In the process S107, if the internal temperature falls to the lower limit temperature Tth2 during the total period measurement at a certain set rotational speed ωp, the operation relating to the shift change described above is interrupted, and then the compressor motor is stopped (S110). ), The recording process related to the second driving information is performed (S111b).

  The second operation information includes on-operation period information Δtc, final set rotation speed information ωrec, information on mode change, and the like. In particular, these pieces of information are information acquired during the activation of the process R100. For example, in the last set rotation speed information ωrec, the last set rotation speed in the process R100 being activated, that is, the set rotation speed immediately before the compressor motor shifts to the off operation.

  As described above, according to the steady-state rotational speed setting process according to the present embodiment, the starting rotational speed ωa is controlled to coincide with the latest final set rotational speed. For this reason, in the steady state rotational speed setting process during startup, the state of the latest thermal load is reflected, and as the steady operation proceeds, the set value of the starting rotational speed ωa follows the state of the thermal load. . Further, by controlling the starting rotational speed ωa, it is possible to avoid a significant change in the changed rotational speed ωb set in the subsequent stage, and thus it is possible to avoid redundancy of the ON operation period in the steady operation.

  In this embodiment, the starting rotational speed ωa set in the process R100 is “starting rotational speed ωa = the latest final set rotational speed”. However, the present invention is not limited to this, and the starting rotational speed ωa set in the process R100 may be calculated based on the final set rotational speed. For example, the starting rotational speed ωa set in the process R100 may be a value obtained by offsetting the final set rotational speed by a predetermined value, or may be calculated by an appropriate function using the final set rotational speed.

  Here, paying attention to the set rotational speed in the descending mode, the set width Δω2 in the descending mode is set to 100 [rpm], but the set rotational speed Δω1 in the ascending mode (500 [rpm ]) Is set smaller. According to this, the automatic change of the set rotational speed in the descending mode is carefully advanced, and the degree of risk that the set rotational speed is deviated from the set rotational speed sufficient to cool the heat load is reduced. .

  In this case, it is preferable that the set width Δω2 is set to be smaller than all the set rotation speeds Δω1, but this is not necessarily protected. For example, a plurality of set values may be given for the set width Δω1 of the ascending mode, and if the set value of Δω2 is smaller than the main set width Δω1, among them, the above-described effect appears surely. That is, in order to produce such an effect, it is impossible to satisfy the absolute condition that the set width Δω2 is set to be smaller than all the set rotational speeds Δω1. However, if the set width Δω <b> 2 is smaller than any of the plurality of prepared Δω <b> 1, the above-described effect is exhibited in that range.

  In addition, the process in which the starting rotational speed ωa is determined by the immediately preceding final set rotational speed ωrec also gives an advantage to the operation that does not deviate from the set rotational speed sufficient to cool the heat load (this is called the ideal set rotational speed). ing. It is assumed that the starting rotational speed ωa set at the start (on restart) of the ON operation is set greatly deviating from the ideal set rotational speed to the low rotational side. Then, in the descending mode, the changed rotational speed ωb immediately thereafter decreases stepwise from the rotational speed ωa, so that the difference from the ideal set rotational speed is not shortened. On the other hand, in the present embodiment, since the starting rotational speed ωa follows the immediately preceding final set rotational speed ωrec, the difference from the ideal set rotational speed is suppressed. In addition, it can be easily understood that the difference from the ideal set rotational speed can be effectively suppressed if the set width Δω2 is set to be small.

  Further, in the present embodiment, when the set rotational speed is automatically changed in the descending mode, even if the condition for repeating this operation continues, when the set rotational speed reaches 1500 [rpm], this rotational speed (hereinafter referred to as critical rotational speed). Will be maintained). Such an operation is also one of the measures not to deviate from the ideal set rotational speed. This is because in the present embodiment, since the rotational speed is set based on a small amount of temperature information, it may happen that the correct mode setting cannot be selected. Therefore, when the operation of continuously reducing the set rotational speed continues, there is a high probability that the rotational speed being set deviates greatly from the ideal set rotational speed.

  For this reason, in this embodiment, a critical rotational speed is provided to prevent an increase in the difference between the rotational speed being set and the ideal set rotational speed. In addition, since the critical rotational speed is provided, it is allowed to provide the descending mode in the preceding stage. The critical rotational speed is preferably lower than the starting rotational speed and higher than the emergency set rotational speed. By setting it as such a rotation speed, descent | fall mode functions to the rotation range which suppresses power consumption, and it can also avoid that the cooling action in descent | fall mode is impaired remarkably.

  In this embodiment, although only a small amount of temperature information can be obtained, the descending mode can be adopted by the various devices described above. Therefore, in the present embodiment, the set rotational speed can be automatically changed in a downward direction in an appropriate scene, so that the power consumption of the compressor motor can be suppressed while the preservation state of the food stock is protected.

  Here, a mode selection process for determining whether the set rotational speed is automatically increased or decreased for the above-described first to third embodiments will be described. The phase of the cooling control indicates a cooling process in the cabinet, and the above-described IPD operation, steady operation operation, and the like correspond to this. In addition, the steady operation may be recognized as a different phase for each scene.

  First, the mode selection at the time of IPD operation | movement is demonstrated with reference to FIG.4 (b). In the figure, a change mode selection recording process R200 is shown. The change mode selection recording process R200 includes a third mode selection process S201 and mode information recording processes S202 to S203.

  The third mode selection process S201 automatically increases the set rotational speed ωp or the set rotational speed ωp automatically based on the final set rotational speed information ωrec set immediately before the compressor motor is turned off. Select the descent mode to descend. In particular, in this embodiment, the threshold information ωth for the final set rotational speed information ωrec is given as “ωth = 3500”, and if the actual final set rotational speed information ωrec is larger than the threshold information ωth, the heat load is large. Ascending mode information advantageous to the cooling action is selected and recorded (S202). If the actual final set rotational speed information ωrec is smaller than the threshold information ωth, descent mode information advantageous for power saving is selected and recorded on the assumption that the thermal load is small (S203).

  This mode information is reflected in the control of the on-operation period that comes next to the off-operation period because the mode selection process is performed after the off-operation period. If the mode selection process is in a BUSY state by other processes, it is only necessary that the selection result is obtained before the start of the changed rotation speed ωb. The same applies to the mode selection process during steady operation.

  In scenes (phases) related to the IPD operation, the information that can be obtained is very limited. Therefore, the mode is selected based only on the final set rotational speed information ωrec. Thus, in the present embodiment, a device is devised so that the mode can be selected using the simplest information during IPD operation.

  Next, mode selection during steady operation will be described with reference to FIG. In the figure, a change mode selection recording process R210 is shown. The change mode selection recording process R210 includes a second mode selection process S210 and mode information recording processes S213 to S215. Of the on operation periods that appear during steady operation, the previous on operation period is referred to as a first on operation period ton1, and the subsequent on operation period is referred to as a second on operation period ton2. However, this calling method only expresses a relative relationship between two predetermined on-operation periods, and the third on-operation period ton3 appears after the second on-operation period ton2. The second on-operation period corresponds to the first on-operation period in the claims, and the third on-operation period here corresponds to the second on-operation period in the claims.

  The second mode selection process S210 includes a process S211 and a process S212, each of which is based on a comparison value between the first on-operation period ton1 and the second on-operation period ton2, and the ascending mode or the descending mode. Either one is selected. In process S211, a threshold value Δth1 is given, and when “ton2 ≧ ton1 + Δth1”, the ascending mode is selected, and in process 213, mode information indicating that this information mode is selected is recorded. On the other hand, in the process S211, when “ton2 <ton1 + Δth1”, the subsequent selection process is left to the process S212.

  The process S212 is given a threshold value Δth2 and selects the descending mode when “ton2 <ton1-Δth2”. In process 214, mode information indicating that this information mode is selected is recorded. On the other hand, when “ton2 ≧ ton1−Δth2”, the process proceeds to step S215, where the mode information is not changed and the mode information is maintained as it is.

  As described above, in the second mode selection process S210 according to the present embodiment, the second on-operation period ton2 is somewhat longer than the first on-operation period ton1, that is, the on-operation time ton is If it changes in the increasing direction over time, the ascending mode is selected because the cooling of the heat load is insufficient. In addition, when the second on-operation period ton2 is somewhat reduced from the first on-operation period ton1, that is, when the on-operation time ton changes in a decreasing direction over time, the thermal load is sufficiently cooled. For example, the descending mode is selected. Further, when the change in the on-operation period ton is very small, it is determined that the change mode being set is appropriate, and the mode setting is maintained.

  As described above, in this embodiment, the mode is selected based on the comparison value during the ON operation period. However, the comparison value is not limited to the difference value as in the present embodiment, and may be a parameter indicating a change in period as a percentage such as “ton2 / ton1”.

  This process S210 can be operated in a scene (phase) in which two or more ON operation periods ton are recorded in the memory circuit. Further, it is also useful to use in a scene where recording information for an off operation period toff described later is not prepared. Further, in the mode selection process S210 according to the present embodiment, the selection result in the mode selection process becomes valid by effectively using the information of the two ON operation periods.

  In particular, it is preferable that both of the on operation periods ton1 and ton2 are continuous operation periods with the off operation period interposed therebetween. As a result, the mode selection process S210 selects a mode based on the most recent information, so the situation of the temperature change at that time can be accurately grasped, and the validity of the above selection result is more certain. Become.

  Next, another mode selection during steady operation will be described with reference to FIG. In the figure, a change mode selection recording process R220 is shown. The change mode selection recording process R220 includes a third mode selection process S220 and mode information recording processes S223 to S225. Of the off operation periods that appear during steady operation, the previous off operation period is referred to as a first off operation period toff1, and the off operation period after this is referred to as a second off operation period toff2.

  The first mode selection processing S220 includes processing S221 and processing S222, each of which performs mode selection based on a comparison value between the first off operation period toff1 and the second off operation period toff2. . In the process S221, a threshold value Δth4 is given, and when “toff2 <toff1−Δth4”, the ascending mode is selected, and the selected mode information is recorded in the process S223. On the other hand, when “toff2 ≧ toff1−Δth4”, the subsequent selection process is left to the process S222.

  In the process S222, the threshold value Δth3 is given, and when “toff2 ≧ toff1 + Δth3”, the descending mode is selected, and the selected mode information is recorded in the process S224. On the other hand, when “toff2 <toff1 + Δth3”, the mode information is not changed and is maintained as it is.

  As described above, in the first mode selection process S220 according to the present embodiment, if the off-operation time toff changes in the decreasing direction over time, the descending mode is selected as the thermal load is sufficiently cooled. To do. Also, if the off operation time toff changes in an increasing direction over time, the ascending mode is selected because the cooling of the heat load is insufficient. When the change in the off operation period toff is very small, the mode setting is maintained.

  The process S230 according to the present embodiment can function in a scene (phase) in which two or more off operation periods toff are recorded in the memory circuit. It is also useful to use it in a situation where the recording information about the on-operation period ton is not prepared. In particular, the off operation period toff represents the most recent thermal load state for the on operation period immediately after the period. For this reason, mode selection process S220 makes the selection result of mode information more appropriate.

  In particular, both of the off operation periods toff1 and toff2 are preferably operation periods that are continuous across the on operation period. As a result, the mode selection process S220 selects a mode based on the most recent information, so the temperature change status at that time can be accurately grasped, and the validity of the above selection result is more certain. Become.

  As described above, according to the motor control device 100 according to the present embodiment, the selection logic related to the mode selection corresponds to each phase of the cooling control, so even if only a small amount of information can be acquired, it is suitable for this situation. A mode selection process is applied, thereby enabling an appropriate mode setting. Further, when the information that can be obtained increases as the phase progresses, the mode selection is performed by effectively using the information, so the validity of the mode selection is assured.

  Usually, since the set rotational speed is provided assuming the heat amount and heat leak amount of the heat load, it is considered that the heat absorption amount of the cooling action does not fall below the heat amount of the heat load in the descending mode. However, there are rare cases where the heat load cannot be sufficiently cooled by the cooling action during the descent mode due to the timing of putting the heat load into the cabinet, the rise of heat leak due to deterioration of the packing, or the abnormal rise of the outside temperature. (See FIG. 11A). In the present embodiment, in order to solve such a problem, the following devices are taken for the operation of steady operation.

  Hereinafter, the rotational speed setting process according to the present embodiment will be described with reference to FIGS. This embodiment is a technique for solving the problem in the descending mode, and only the descending mode will be described. In the present embodiment, it is assumed that the changed rotation speed setting process is composed of processes S107 and S114 to S118.

  Similar to the previous embodiment related to the steady operation, in this embodiment, when the start time of the ON operation period of STEP (M) is reached, the immediately preceding OFF operation period is recorded (S111a), and is turned on at the starting rotational speed ωa. The operation is started (S101). In this embodiment, it is assumed that the starting rotational speed ωa is 3000 [rpm]. In the change mode setting process S102, it is assumed that the descending mode is set.

  Thereafter, the period tins (4) for the operation of the starting rotational speed ωa is measured (S114), and when the period expires (the specified period t (th4)), the starting rotational speed ωa is switched to the changed rotational speed ωb. (S115). Even in the present embodiment, the set width Δω for decreasing the changed rotational speed ωb is set to 100 [rpm]. In this scene, the speed decreases from 3000 [rpm] by 100 [rpm] every time the specified period is up. To do. The specified period t (th4) here is set to 15 [min].

  In the present embodiment, as shown in FIG. 12, a fifth operation time measuring process S116, a fifth switching rotation speed setting process S117, and a process S118 are newly added. Among these, the fifth operation time measurement process S116 is given a predetermined threshold value Δtσ5 for the period, counts the integration period Σtins starting from the start time t (m), and the integration period Σtins is the predetermined threshold value Δtσ5. It is determined whether or not (predetermined integration period) has been reached. That is, the fifth operation time measurement process S116 counts a period during which the set rotational speed is decreasing stepwise, and performs threshold determination for this period. In the present embodiment, the predetermined integration period Δtσ5 is set to 30 [min], and after the elapse of this time, the fifth switching rotation speed setting process S117 is performed.

  The process S117 is higher than the set rotational speed when the predetermined integration period Δtσ5 is reached. Hereinafter, the set rotational speed that is set to be increased in the process S117 will be referred to as a separation set rotational speed ωc. The separation set rotational speed ωc is given a setting range at the time of separation so that it increases by 500 [rpm] after this processing functions. Accordingly, the separation setting width which turns to the rising side is given larger than the setting width Δω (decreasing side setting width) when the set rotational speed is lowered in the descending mode, so that the cooling function does not function sufficiently. Even in the scene, this can be solved at once, and its cooling action can be quickly restored to an appropriate state.

  In setting the separation speed ωc, in addition to the above-described method, it is also useful to make the separation speed ωc coincide with the starting speed ωa. The starting rotational speed ωa is an appropriate temperature that has been cooled to the lower limit temperature Th2 in the immediately preceding ON operation period. As long as the thermal load does not change abruptly, the starting rotational speed ωa is returned to this set rotational speed ωa, This is because it can be predicted that will be exhibited. Further, according to this, by suppressing the amount of decrease in the set rotational speed until the rotational speed ωc at the time of separation is suppressed, it is possible to restore the sufficient cooling effect with the minimum necessary setting change.

  In this embodiment, a part of the rotation speed setting process during the steady operation described above is changed. The steady-state rotation speed setting process R100 according to the present embodiment is different in subsequent processes in accordance with the mode setting (S102) set at the beginning of the ON operation. Hereinafter, when the rising mode is set at the beginning of the on-operation, the rotation speed setting by the first steady-state rotation speed setting processing R101 is performed (see FIG. 13), and the descending mode is set at the beginning of the on-operation. In this case, it is assumed that the rotational speed is set by the second steady-state rotational speed setting process R102 (see FIG. 14).

  In the first steady-state rotation speed setting process R101, a sixth operation time measurement process S120 is provided instead of the fourth operation time measurement process S114, as compared with the third embodiment (FIG. 7). Further, a sixth switching rotation speed setting process S121 is provided instead of the fourth switching rotation speed setting process S115 (see FIG. 13).

  In the sixth operation time measurement process S120, the total period tins (6) for the operation at the starting rotational speed ωa is measured (S120), and a plurality of thresholds are set for parameters relating to this period. The plurality of threshold values are provided in consideration of differences in their properties. In the present embodiment, the plurality of threshold values include specified period information t (th6p) and variable period information t (th6q). These pieces of threshold information are prepared as a thermal load state analysis tool.

  The specified period information t (th6p) is information representing the first threshold value in the claims and is information representing a preset fixed time or period. On the other hand, the fluctuation period information t (th6q) is variable information determined according to the actual heat load, and is threshold information belonging to the second threshold in the claims. As described above, the threshold information of both is still information for analyzing the heat load state, but the difference in properties such as whether the threshold is given as an absolute value or the threshold is given as a relative value. There is.

  In the first steady-state rotation speed setting process R101, a plurality of comparison criteria, i.e., threshold information, for the above-described period elapsed parameters are set. For this reason, a plurality of comparison results between the parameter tins (6) and the threshold information are also acquired. If the measured total period tins (6) has reached either one (or both) of the above, the process proceeds to step S121, and the set rotational speed is shifted up by one step.

  As described above, the steady-state rotation speed setting process R101 according to the present embodiment includes a process for setting a plurality of threshold information for one parameter tins (6) created based on limited temperature information. Has been. Therefore, according to the present embodiment, by using threshold information having different properties, it is possible to perform multi-faceted analysis for one parameter, and realize the optimum setting of the set rotational speed.

  For example, in the present embodiment, the immediately preceding off operation period (first period parameter) is set as the variable period information t (th6q). On the other hand, the specified period information t (th6p) is set as 15 [min]. Therefore, in this embodiment, even if the immediately preceding off operation period (first period parameter) is significantly longer than 15 [min], the set rotational speed is shifted up by the specified period information t (th6). In addition, when the immediately preceding off operation period is shorter than 15 [min], it is possible to quickly change the rotational speed setting with the variable threshold information t (thq) without waiting for the determination result using the fixed threshold. . Such complementary complementing operation can prevent redundant operation of the compressor, which is advantageous for securing the defrost period.

  In this embodiment, the off-period of the compressor motor is used as the fluctuation period information t (th6q). This is because the rotational speed can be set using the latest information. However, when information on the immediately preceding off operation period cannot be obtained, the on operation period may be used.

  Next, in the second steady state rotation speed setting process R102, a sixth operation time measurement process S120 is provided instead of the fourth operation time measurement process S114 as compared with the fifth embodiment (FIG. 12). Yes. Further, a sixth switching rotation speed setting process S121 is provided instead of the fourth switching rotation speed setting process S115. Further, a seventh operation time measurement process S122 is provided instead of the fifth operation time measurement process S116. Further, in the process R102, the processes S117 to S118 in the fifth embodiment are removed, and a mode change confirmation process S123 and an ascending mode setting process S124 are added instead.

  In the sixth operation time measurement process S120, as in the process R101, the total period tins (6) for the operation at the starting rotational speed ωa is measured (S120), and a plurality of threshold values are set for parameters relating to this period. . In the present embodiment, specified period information t (th6r) and variable period information t (th6s) are set, and these values are appropriately given as a tool for analyzing the thermal load.

  In the present embodiment, ½ times the second off period (second period parameter) is set as the variable period information t (th6s). On the other hand, the specified period information t (th6r) is set as 10 [min]. Therefore, in this embodiment, even if the second period parameter is longer than 10 [min], the set rotational speed is shifted down based on the specified period information t (th6r). Further, when the period parameter of the immediately preceding information is shorter than 10 [min], the rotational speed setting can be quickly changed by the variable threshold information t (th6s) without waiting for the determination result using the fixed threshold information. .

  In the seventh operation time measurement process S122, a predetermined threshold value Δtσ7 related to the period is given, the integration period Σtins starting from the start time is counted, and the integration period Σtins reaches the predetermined threshold value Δtσ7 (predetermined integration period). It is determined whether or not. In the present embodiment, the predetermined integration period Δσ7 is “twice the first period parameter”.

  Therefore, in a series of cyclic processes in which “process S120 → process S121 → process S122” is repeated, an optimum setting of the set rotational speed is performed based on a multifaceted analysis result. Thereafter, in process S122, the integration period Σtins is set to a predetermined integration time. It is checked whether or not the period Δσ7 has been reached.

  When the integration period Σtins reaches the predetermined integration period Δσ7, the mode change confirmation process S123 is executed. At this time, if the mode setting is maintained in the descending mode, the second steady-state rotation speed setting process R102 returns to the process S120, and repeats the shift-down operation for every elapsed period until the predetermined integration period Δtσ7 is reached. On the other hand, when the predetermined integration period Δtσ7 is reached for the first time, the process R102 switches the mode setting to the ascending mode, shifts the set rotational speed one step, and measures the duration of the set rotational speed. Further, in the process R102, if the increase mode has already been set, the upshift operation of the set rotational speed is repeated every time the period elapses.

  As described above, according to the present embodiment, the rotational speed can be set by switching to the ascending mode during operation in the descending mode. Therefore, even if the setting mode already performed does not correspond to the current heat load, this mode switching It is possible to eliminate mode setting mistakes and optimize the set rotational speed. Since the set rotational speed is recovered as described above, the rise in the internal temperature is minimized, and the food stock is stored in a preferable state.

  Here, a more advanced mode setting process will be described. FIG. 15 shows change mode selection recording processing according to the present embodiment. As shown in the figure, the change mode selection recording process R240 includes a current mode determination process S230, a fourth mode selection process S240, and mode information recording processes S242 to S246. In the change mode selection recording process R240, the mode selection process is performed after entering the off operation period, and the mode information selected thereby is reflected in the control of the on operation period that comes after the off operation period. The

  The current mode discrimination process S230 accesses the memory circuit to grasp the selection mode (hereinafter referred to as the current selection mode or the current selection mode information) in the on-operation period ton immediately before the process S240 is activated. Get information. Thus, in the current mode determination process S230, it is determined whether the current mode setting is the ascending mode or the descending mode.

  The fourth mode selection process S240 includes a process S241 that functions when the current selection mode is the ascending mode and a process S244 that functions when the current selection mode is the descending mode. These mode selection processes S241 and S244 acquire the rotation speed change information recorded in the memory circuit and grasp how the latest set rotation speed has been changed. Specifically, it is determined whether it is automatically changed so as to increase the set rotational speed and reaches the present, or is automatically changed so as to decrease the set rotational speed and reaches the present.

  The rotation speed change information is not limited to information provided in addition to the set rotation speed. For example, if the history of the set rotation speed is left in the memory circuit, it is possible to grasp that the set rotation speed has been changed up to now by using the two consecutive rotation speeds that have been set recently. . The rotation speed change information described here may be any information that can grasp the changing process of the set rotation speed in this way. Further, the rotation speed change information and the current selection mode information belong to the “operation information” described above.

  In the mode information recording processes S242 to S246, mode selection information corresponding to the selection result is recorded in the memory circuit. Specifically, mode information corresponding to the ascending mode is recorded in steps S242 and S246, and mode information corresponding to the descending mode is recorded in steps S243 and S245.

  The fourth mode selection process S240 is performed on the basis of both the first condition on how the current selection mode is set and the second condition regarding the changing process of the set rotational speed. Determine the selection mode reflected in the operation. That is, in the fourth mode selection process S240, mode selection is performed based on both the current selection mode information and the rotation speed change information.

  According to this embodiment, for example, when the current selection mode is the ascending mode and the set operation speed is increased and the off operation period starts, it is recognized that further cooling is necessary. Prepare for the driving period. In addition, if the current selection mode is the ascending mode and the set operation speed is not increased (shifted up) and the system enters the off operation period, the descent mode is set and the next operation is performed because the heat load is sufficiently cooled. Prepare for the period. In addition, if the current selection mode is the descent mode and the set rotation speed is increased (shifted up) and then the off operation period starts, the heat load may have been put into the cabinet. To prepare for the next operation period. If the current selection mode is the descent mode and the set operation speed is lowered before entering the off operation period, it is considered that the heat load is sufficiently cooled to the inside, so the descent mode is set and the next operation Prepare for the period.

  As described above, according to the mode selection process R240 according to the present embodiment, different information is used effectively and the mode is set through a plurality of determination processes. Therefore, more detailed determination logic is introduced. Therefore, the validity of the mode selection is further ensured.

  Note that the above-described determination logic is not limited to the combination of the current mode determination process S230 and the fourth mode selection process S240, and appropriately combines various mode selection processes described in the fourth embodiment. The validity of the selection can be further confirmed.

  Further, the following “fifth mode selection process S250” may be combined with the various mode determination logics described above (see FIG. 16). The fifth mode selection process S250 measures the total period tins (f) from the start timing t0 for the off operation period. In the fifth mode selection process S250, the threshold value t (thf) is appropriately set, and this is compared with the total period tins (f) to determine the mode setting (S251, S252).

  In the present embodiment, the threshold value t (thf) is offset to the shorter period side by Δt than the previous off operation period tins (e), and based on this, whether the thermal load is large, that is, cooling of the thermal load. The state is determined. According to such a mode selection process S250, it can be determined whether or not a new thermal load has been applied during the off operation period. Therefore, it is very useful to set this as one of the above-described mode determination logics.

  The present embodiment is an application technique using the third embodiment (FIG. 7) and the fourth embodiment (FIG. 4B, FIG. 8, and FIG. 9). Hereinafter, based on these technologies, the present embodiment will be described with reference to FIG. FIG. 10 shows a composite routine according to the present embodiment. The composite routine R300 includes the mode selection recording processes R200, R210, and R220 described in the fourth embodiment, the rotation speed setting process R100 described in the third embodiment, and the priority that is a characteristic part of the present embodiment. And mode selection processing S310.

  The mode selection recording process R200 is a process for setting the mode based on the final set rotational speed ωrec, and this is called the third mode selection recording process R200. The mode selection process R210 is a process for setting the mode based on the increase / decrease change of the on-operation period ton, and this is called the second mode selection process R210. The mode selection recording process R220 is a process for setting the mode based on the increase / decrease change in the off operation period toff, and is referred to as the first mode selection recording process R210. The rotation speed setting process R100 shown in FIG. 7 will be described with reference to FIG. 7. However, the rotation speed setting process (FIGS. 12 to 14 and the like) described in other places is not limited to this. There may be.

  The composite routine R300 according to the present embodiment includes mode selection recording processes R200 to R220, and controls the compressor motor by using a mode setting such as an ascending mode or a descending mode. The composite routine R300 is prepared with a plurality of mode selection recording processes such as mode selection recording processes R200 to R220.

  The first mode selection recording process R220 includes a first mode selection process S220 for observing the off operation period toff (see FIG. 9). In the first mode selection process S220, mode information is selected based on a threshold value (selection criterion) related to the off operation period toff. The second mode selection recording process R210 includes a second mode selection process S210 for observing the ON operation period ton (see FIG. 8). In the second mode selection process S210, mode information is selected based on a threshold value (selection criterion) related to the on-operation period ton. The third mode selection recording process R200 includes a third mode selection process S200 for checking the final set rotational speed (see FIG. 4B). In the third mode selection process S200, mode information is selected according to a selection criterion related to the set rotational speed.

  Thus, the plurality of mode selection processes each have an individual selection criterion, and mode information is selected and created based on this. As described in the previous embodiment, these mode information are processing results each having a certain level of reliability related to mode setting. The creation of mode information means creation of data representing the mode information in a memory circuit or a CPU register.

  The priority mode selection process S310 includes processes S311 to 313 as illustrated. Among these, if the latest mode information (first mode information) by the first mode selection recording process R220 has been created, the process S311 sets the first mode information as priority mode information (S313). . In the process S312, when the latest mode information (second mode information) by the second mode selection recording process R210 is created, if the first mode information is not the priority mode information, the second mode information Is set as priority mode information (S313). Further, in the process 313, when neither the first mode information nor the second mode information can be acquired, the mode information (third mode information) created in the third mode selection recording process R200 is used as the priority mode information. Set.

  Since the third mode information is a determination result based on the set rotational speed, the reliability is somewhat lower than other mode information that can directly monitor the rate of change in temperature. On the other hand, since the first mode information conveys information that is more immediate in the off operation period than in the on operation period, it is considered that the first mode information is more reliable than the second mode information. Thus, the authenticity of the mode information is such that the first mode information is the highest, the second mode information is the next order, and the third mode information is the second order. It becomes. That is, the priority mode selection process S310 selects one mode information in descending order of reliability and sets this as the priority mode information.

  In the rotation speed setting process R100, as described in the third embodiment (FIG. 7), the mode information is confirmed by the change mode setting process S102, and based on the mode information (rising mode information, descending mode information). Determine the speed change mode. In particular, according to the present embodiment, the change mode setting process S102 extracts priority mode information from a plurality of recorded mode information and automatically changes the set rotational speed using this as the mode information. That is, in the rotation speed setting process R100, when the priority mode information is the increase mode information among the recorded mode information, the automatic change of the set rotation speed is shifted up in the increase mode. On the other hand, when the above-described priority mode information is the descending mode information, the automatic change of the set rotational speed is shifted down in the descending mode.

  As described above, according to the motor control device 100 according to the present embodiment, the mode information selected by the mode selection process with superior reliability is prioritized, so the mode setting based on this information matches the state of the thermal load. It contributes to the optimum setting of the rotation speed. Further, in this motor control device, mode information is created by a plurality of mode selection processes, and each mode information is a processing result having a certain level or more of reliability related to mode setting. . Therefore, when the result of the mode selection process with the most credibility is not obtained, the motor control device realizes control that matches the state of the heat load using the mode information prepared next.

  Further, according to the present embodiment, the mode selection process in which the mode information has the highest priority is given with a selection criterion for the off-operation period of the compressor motor. Since the mode information is information reflecting the latest information about the change state of the heat load, the setting rotation speed change mode implemented based on this, the increase mode is set to increase the cooling action, Setting that matches the heat load is performed reliably, such as setting the descending mode when the cooling action is sufficient.

  Furthermore, according to the present embodiment, since the mode setting is performed based on the set rotation speed or the period from Tth1 to Tth2, the motor control circuit 100 can perform the mode setting with a small amount of temperature information. Therefore, the motor control circuit 100 according to the present embodiment is useful in a system using a mechanical thermostat.

  In this embodiment, priority mode information is set by a combination of the first mode selection process S220, the second mode selection process R210, and the third mode selection process S201. However, the technical idea described in the scope of claims is not limited to this, and various modifications are possible. For example, as shown in FIG. 17, the fifth mode selection recording process R250 is used as the highest-priority mode selection process instead of the first mode selection recording process R220, and the fourth mode selection recording process R210 is replaced with the fourth mode selection recording process R210. The mode selection recording process R240 may be a subsequent mode selection process (see Example 4).

  Even in such a case, the mode selection process in which the mode information has the highest priority is given a selection criterion for the off-operation period of the compressor motor. Therefore, as described above, in the set rotation speed change mode, setting that matches the heat load is reliably performed.

  100 compressor motor control device, 120 power conversion circuit, 160 control circuit, 170 mechanical thermostat, R100 rotation speed setting process, R200 mode selection process.

Claims (3)

In a compressor motor control device for a cooler comprising a rotation speed setting process for automatically changing the rotation speed of a compressor motor based on the passage of time,
The rotation speed setting process automatically changes the set rotation speed if the measured period has reached at least one of the comparison results with a plurality of threshold values that are determination criteria for the passage of the period. A compressor motor control device for a cooling machine.   The plurality of threshold values include a first threshold value that represents a fixed time or period, and a second threshold value that represents a variable time or period. Compressor motor control device for cooling machine.   3. The compressor motor control device for a cooler according to claim 2, wherein the second threshold value is a threshold value representing an ON operation period or an OFF operation period of the compressor motor.

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