JP4458156B2 - Signal correction device and air conditioner - Google Patents

Description

  The present invention relates to a signal correction apparatus. Moreover, this invention relates to the air conditioning apparatus provided with the signal correction apparatus.

  The air conditioner includes various devices such as a compressor and a fan. A motor is often used as a power source for these devices. The motor is connected to a motor driving unit (hereinafter referred to as a motor driver) composed of a plurality of switching elements, and can be rotated by a driving voltage output when each switching element in the motor driver is turned on and off. it can.

In addition, in order to operate various devices such as a compressor and a fan in an appropriate state, the rotational speed of the motor may be controlled. For such motor speed control, a motor current supplied to the motor is often used. Here, as a method for detecting the motor current, for example, as disclosed in Patent Document 1, a shunt resistor connected in series on the wiring through which the motor current flows, and an operational amplifier that amplifies the voltage across the shunt resistor are configured. A technique for detecting a motor current by a current detection unit is known.
JP 2005-192358 A

  However, since there are variations in the value of the shunt resistor and the gain of the operational amplifier constituting the current detection unit, the motor current detected by the current detection unit (that is, the detection result of the current detection unit) and the actual motor current There may be a difference between them. Furthermore, each component, such as a resistor and an operational amplifier, and a motor have characteristics that generate heat when a current flows, such as when the motor rotates. Therefore, the difference between the detected motor current and the actual motor current also changes depending on the heat generation degree of each component and the motor. Such a difference may affect the rotation speed control of the motor that is performed using the motor current that is the detection result of the current detection unit.

  In addition to the case where the motor and the motor driver are separately provided, the motor and the motor driver may be built in the motor device. However, in such a motor device, when the technique according to Patent Document 1 is applied to detect the motor current flowing in the motor portion, the configuration of the motor device causes the shunt resistor to be on the wiring connected in series. In addition to the motor current, the drive current flowing through the motor driver flows. Therefore, the process of calculating the motor current from the drive current and the motor current detected by the current detection unit is performed, but since the drive current changes with the change in the rotation speed of the motor, in order to calculate the motor current accurately, It is necessary to obtain an accurate driving current.

  Accordingly, the present invention has been made in view of the above-described points, and an object of the present invention is to provide a signal correction apparatus that can accurately acquire a signal related to a motor, such as a motor current, and an air equipped with the same. It is to provide a harmony device.

A signal correction apparatus according to a first aspect includes an A / D conversion unit, an offset update unit, and a correction unit. The A / D converter performs A / D conversion on a signal related to the motor. The offset update unit updates an offset value used for correcting the A / D converted signal based on the signal A / D converted by the A / D conversion unit during rotation of the motor. The correction unit corrects the A / D converted signal using the updated offset value. The offset updating unit captures the signal A / D converted by the A / D conversion unit a predetermined number of times, and counts the number of captured signals for each signal value. Next, the offset update unit determines the value of the signal having the largest number of counted signals as the offset value, or at least calculates the weighted average value of the signals acquired based on the value of the signal having the largest number of counted signals. This is calculated and determined as an offset value. In particular, the signal is the sum of motor current and drive current. Here, the motor current is a current supplied to the motor. The drive current is a current that is different from the motor current and is supplied to the motor drive unit for driving the motor. The drive current is determined as an offset value from the sum of the motor current and the drive current as the signal.

According to this signal correction apparatus, when the motor rotates, the offset value of the signal related to the motor is updated, and the signal related to the motor is corrected based on the updated offset value. In particular, the offset updating unit determines the value of the signal having the largest number among the signals captured a predetermined number of times as the offset value, or determines the weighted average value of the values of the signal having the largest number as the offset value. As a result, the offset value can be accurately obtained, so that an accurate signal is output from the signal correction device. Therefore, for example, various controls such as motor rotation speed control can be performed without problems.
In particular, this signal correction apparatus can be applied when the motor and the motor drive unit are built in the motor apparatus. When the motor and the motor drive unit are built in the motor device, due to the structure, the wiring through which the motor current after the motor is energized and the wiring through which the drive current after the motor drive unit is energized are separated. It is difficult to provide. However, when the signal correction apparatus is applied in such a case, the driving current is determined as an offset value out of the sum of the A / D converted motor current and the driving current, and this offset value is the sum of the motor current and the driving current. Used to correct Therefore, the signal correction apparatus can calculate the motor current with high accuracy by subtracting the offset value determined as the drive current from the sum of the motor current and the drive current, for example.

  A signal correction apparatus according to a second aspect of the present invention is the signal correction apparatus according to the first aspect of the present invention, wherein the offset update unit includes a value within a predetermined range of the signal that has been A / D converted by the A / D conversion unit. The offset value is updated using the signal.

  According to this signal correction apparatus, since the signal included in the predetermined range is used for updating the offset value, the number of signals used for updating the offset can be reduced. Therefore, when the offset update unit is constituted by a microcomputer, the load on the microcomputer can be reduced. Further, the calculation time of the offset value can be shortened.

A signal correction apparatus according to a third aspect is the signal correction apparatus according to the first or second aspect , wherein the correction unit subtracts the offset value from the sum of the A / D converted motor current and drive current, calculate.
According to this signal correction apparatus, the motor current can be obtained by subtracting the drive current as an offset value from the sum of the motor current and the drive current. Since the drive current as the offset value is obtained using the method of the first aspect, it can be said that the drive current is an accurate value. Therefore, the signal correction apparatus can obtain the motor current with high accuracy.

A signal correction apparatus according to a fourth aspect includes an A / D conversion unit, an offset update unit, and a correction unit. The A / D converter performs A / D conversion on a signal related to the motor. The offset update unit updates an offset value used for correcting the A / D converted signal based on the signal A / D converted by the A / D conversion unit during rotation of the motor. The correction unit corrects the A / D converted signal using the updated offset value. Then, the offset update unit takes in the signal A / D converted by the A / D conversion unit, and counts the number of taken-in signals for each signal value. When any of the number of signals counted for each signal value reaches the third predetermined number, the offset updating unit determines the value of the signal reaching the third predetermined number as the offset value. Alternatively, when any of the number of signals counted for each signal value reaches the fourth predetermined number, the offset update unit weights the signal acquired based on at least the value of the signal reaching the fourth predetermined number An average value is calculated and determined as an offset value. In particular, the signal is the sum of motor current and drive current. Here, the motor current is a current supplied to the motor. The drive current is a current that is different from the motor current and is supplied to the motor drive unit for driving the motor. Of the sum of the motor current and the drive current as the signal, the drive current is determined as an offset value.

According to this signal correction apparatus, the offset value is determined to be the value of the signal that has reached the third predetermined number earliest among the captured signals. Alternatively, according to this signal correction apparatus, the weighted average value of the values of the signals that have reached the fourth predetermined number earliest among the captured signals is determined as the offset value. In this way, the signal correction apparatus can determine the offset value more accurately.
In particular, this signal correction apparatus can be applied when the motor and the motor drive unit are built in the motor apparatus. When the motor and the motor drive unit are built in the motor device, due to the structure, the wiring through which the motor current after the motor is energized and the wiring through which the drive current after the motor drive unit is energized are separated. It is difficult to provide. However, when the signal correction apparatus is applied in such a case, the driving current is determined as an offset value out of the sum of the A / D converted motor current and the driving current, and this offset value is determined based on the motor current and the driving current. Used for sum correction. Therefore, the signal correction apparatus can calculate the motor current with high accuracy by subtracting the offset value determined as the drive current from the sum of the motor current and the drive current, for example.

A signal correction apparatus according to a fifth aspect of the present invention is the signal correction apparatus according to the fourth aspect of the present invention, wherein the offset update unit includes a value within a predetermined range of the signal that has been A / D converted by the A / D conversion unit. The offset value is updated using the signal.

  According to this signal correction apparatus, since the signal included in the predetermined range is used for updating the offset value, the number of signals used for updating the offset can be reduced. Therefore, when the offset update unit is constituted by a microcomputer, the load on the microcomputer can be reduced. Further, the calculation time of the offset value can be shortened.

A signal correction apparatus according to a sixth aspect of the present invention is the signal correction apparatus according to the fourth or fifth aspect , wherein the correction unit subtracts the offset value from the sum of the A / D converted motor current and drive current, and calculates the motor current. calculate.

According to this signal correction apparatus, the motor current can be obtained by subtracting the drive current as an offset value from the sum of the motor current and the drive current. Since the drive current as the offset value is obtained using the method of the invention 4 , it can be said that the drive current is an accurate value. Therefore, the signal correction apparatus can obtain the motor current with high accuracy.

An air conditioner according to a seventh aspect includes the signal correction device according to any one of the first to sixth aspects, a fan motor, a fan, and a control unit. The fan is driven to rotate by a fan motor. The control unit controls the amount of air sent from the fan to the room based on the signal corrected by the correction unit of the signal correction device.

For example , a case where the correction unit calculates the motor current by subtracting the drive current as an offset value from the sum of the A / D converted motor current and the drive current is taken as an example. In this case, the air conditioner can perform control such that, for example, the air volume sent into the room is constant, based on the accurate motor current calculated by the correction unit.

Since an accurate signal is output from the signal correction apparatus according to the first aspect of the invention, various controls such as motor rotation speed control can be performed without any problem. In particular, the signal correction apparatus according to the first aspect of the invention can calculate the motor current with high accuracy by subtracting the offset value determined as the drive current from, for example, the sum of the motor current and the drive current.

  According to the signal correction device according to the second aspect of the invention, the number of signals used for updating the offset value can be reduced. Therefore, when the offset update unit is configured by a microcomputer, the load on the microcomputer can be reduced. Further, the calculation time of the offset value can be shortened.

With the signal correction device according to the third aspect , the motor current can be obtained with high accuracy.
According to the signal correction apparatus according to the fourth aspect, the offset value can be obtained more accurately. In particular, according to the signal correction apparatus according to the fourth aspect of the invention, the motor current can be accurately calculated by subtracting the offset value determined as the drive current from the sum of the motor current and the drive current, for example.

According to the signal correction apparatus according to the fifth aspect of the present invention, when the offset update unit is configured by a microcomputer, the load on the microcomputer can be reduced. Further, the calculation time of the offset value can be shortened.
With the signal correction apparatus according to the sixth aspect , the motor current can be obtained with high accuracy.

According to the air conditioner pertaining to the seventh aspect of the invention, it is possible to perform control such that the amount of air sent into the room is constant, for example, based on the accurate motor current calculated by the correction unit.

  Hereinafter, a signal correction device according to the present invention and an air conditioning apparatus including the same will be described with reference to the drawings.

(1) Configuration FIG. 1 is a schematic plan view showing the configuration of an air conditioner 1 according to an embodiment of the present invention. An air conditioner 1 in FIG. 1 is a desiccant type external air conditioner in which an adsorbent such as silica gel is supported on the surface of a heat exchanger, and performs a cooling / dehumidifying operation or a heating / humidifying operation on air supplied to an indoor space. Do the driving.

  As shown in FIGS. 1 to 4 and 8, such an air conditioner 1 mainly includes a casing 2, first and second heat exchangers 3 a and 3 b, a compressor 4, a compressor motor 5, 1 and 2nd fan 6a, 6b, the 1st fan motor 7, the 2nd fan motor apparatus 8, the electric current detection apparatus 9, the signal correction apparatus 10, and the control part 11 are provided. And the 1st heat exchanger 3a, the 2nd heat exchanger 3b, and the compressor 4 comprise the refrigerant circuit as shown in FIG.

(1-1) Casing The casing 2 has a substantially rectangular parallelepiped shape, and the first and second heat exchangers 3a and 3b, the compressor 4, the first and second fans 6a and 6b, and the like are included therein. Is stored. In FIG. 1, a first suction port 22 for sucking outdoor air OA into the casing 2 and a second suction port 23 for sucking indoor air RA into the casing 2 are formed in the left side plate 21 a of the casing 2. Has been. On the other hand, the right side plate 21b of the casing 2 is formed with a first air outlet 24 for exhausting the exhaust air EA to the outside and a second air outlet 25 for supplying the air SA after humidity adjustment to the room. ing. Note that a pipe extending into the room is connected to the second air outlet 25, and the air SA after being conditioned is supplied to the room through this pipe.

  A partition plate 26 that partitions the inside of the casing 2 is provided inside the casing 2. By the partition plate 26, the inside of the casing 2 is divided into an air chamber S1 and a machine chamber S2. The air chamber S1 is provided with first and second heat exchangers 3a and 3b and partition members for the heat exchangers 3a and 3b. The machine chamber S2 includes first and second heat exchangers 3a. , 3b other devices (specifically, the compressor 4, the first and second fans 6a, 6b, etc.) are arranged.

(1-2) Heat Exchanger The first heat exchanger 3a and the second heat exchanger 3b are cross fin type fin-and-tube heat exchangers as shown in FIG. A large number of aluminum fins 31 formed in a plate shape and a copper heat transfer tube 32 penetrating the fins 31 are provided. On the outer surfaces of the fins 31 and the heat transfer tubes 32, an adsorbent that adsorbs moisture contained in the air passing through the heat exchangers 3a and 3b is supported by dip molding (dip molding) or the like. Here, examples of the adsorbent include zeolite, silica gel, activated carbon, hydrophilic or water-absorbing organic polymer material, ion-exchange resin material having carboxylic acid group or sulfonic acid group, and temperature-sensitive polymer. A functional polymer material or the like can be used.

  Such first and second heat exchangers 3a and 3b are connected to each other via an expansion valve 13, as shown in FIG. For example, the first heat exchanger 3a exchanges heat with the indoor air RA sucked from the second suction port 23, and the second heat exchanger 3b heats the outdoor air OA sucked from the first suction port 22 and heat Exchange. The indoor air RA after the heat exchange is discharged outside as the exhaust air EA, and the outdoor air OA after the heat exchange is supplied indoors as the air SA after humidity adjustment.

  The first and second heat exchangers 3a and 3b include a first state where the first heat exchanger 3a functions as a condenser and the second heat exchanger 3b functions as an evaporator, and the first heat exchanger 3a includes Control is performed by the control unit 11 so that the evaporator and the second heat exchanger 3b can take either the second state in which the evaporator or the second heat exchanger 3b functions as a condenser. In the first state, the adsorbent regeneration operation that desorbs moisture from the adsorbent when the first heat exchanger 3a functions as a condenser, and the adsorbent when the second heat exchanger 3b functions as an evaporator. An adsorbing operation for adsorbing moisture on the surface is performed. Further, in the second state, an adsorption operation for adsorbing moisture to the adsorbent when the first heat exchanger 3a functions as an evaporator, and moisture from the adsorbent when the second heat exchanger 3b functions as a condenser. An adsorbent regeneration operation for desorbing is performed. As described above, the adsorption operation and the regeneration operation are alternately performed, and the flow paths of the air EA and SA that pass through the heat exchangers 3a and 3b and are supplied indoors and outdoors are switched. Moisture adsorption and release (ie desorption) can be performed continuously. Therefore, the air conditioning apparatus 1 can perform various operations while maintaining the dehumidifying performance or the humidifying performance.

  Here, the flow path switching of the air EA, SA that passes through the heat exchangers 3a, 3b and is supplied indoors and outdoors is performed by a switching damper (not shown). The switching damper is blown out from the first outlet 24 or the first outlet 25 after the outdoor air OA and the indoor air RA have passed through either the first heat exchanger 3a or the second heat exchanger 3b. The air flow path is switched.

(1-3) Compressor and Compressor Motor The compressor 4 is connected to the first heat exchanger 3a and the second heat exchanger 3b via the four-way switching valve 12, as shown in FIG. . The compressor 4 compresses the refrigerant from the first heat exchanger 3a or the second heat exchanger 3b that functions as an evaporator. The compressor 4 that performs the compression operation is driven by a compressor motor 5.

  The compressor motor 5 is connected to the compressor 4. Such a compressor motor 5 is, for example, a brushless DC motor, and is rotationally driven by a driver 51 (FIG. 8) for the compressor motor 5.

(1-4) Fan and Fan Motor As shown in FIG. 1, the first fan 6 a is provided at a position corresponding to the first air outlet 24, and the exhaust air EA is casing through the first air outlet 24. 2 Send out outside (specifically, outdoors). The 2nd fan 6b is provided in the position corresponding to the 2nd blower outlet 25, and sends out the air SA after humidity control outside the casing 2 (specifically indoors) through the 2nd blower outlet 25. As shown in FIG. The first fan 6a is rotationally driven by a first fan motor 7 (FIG. 8), and the second fan 6b is rotationally driven by a second fan motor device 8 (FIG. 8).

  The first fan motor 7 is connected to the first fan 6a. The first fan motor 7 is a brushless DC motor, for example, similarly to the compressor motor 5, and the rotation of the first fan motor 7 is controlled by a first motor driver 71 for the first fan motor 7. The second fan motor device 8 is connected to the second fan 6b, and includes a second fan motor 81 and a second motor driver 82 (corresponding to a motor drive unit) as shown in FIGS. It is. The second fan motor 81 is, for example, a brushless DC motor, and specifically includes a rotor made of a permanent magnet having a plurality of magnetic poles and a stator having a drive coil. The second motor driver 82 is for rotationally driving the second fan motor 81, and includes a switching element for energizing the drive coil of the second fan motor 81. The second motor driver 82 having such a configuration outputs a drive voltage corresponding to the position of the rotor with respect to the stator to the second fan motor 81.

(1-5) Current Detection Device The current detection device 9 is for detecting the current output from the second fan motor device 8, and as shown in FIG. Has been implemented. Here, the printed circuit board P1 and the second fan motor device 8 are connected by three harnesses L1, L2, and L3 between the interface IF1 of the printed circuit board P1 and the interface IF2 of the second fan motor device 8. . Of these three harnesses L1 to L3, two harnesses L1 and L2 are power harnesses output from a motor power supply device 90a and a drive power supply device 90b, which will be described later, and the remaining one harness. The harness L <b> 3 is a GND harness for the second fan motor device 8.

  Such a current detection device 9 includes a motor power supply device 90a, a drive power supply device 90b, a motor power supply wiring 91, a drive power supply wiring 92, a current leveling unit 93, a GND wiring 94, a current detection unit 95, an instantaneous current. A detection unit 96 and an average current detection unit 97 are provided.

[Motor power supply and drive power supply]
The motor power supply device 90a generates a power supply for supplying the second fan motor 81 (hereinafter referred to as a motor power supply). The drive power supply device 90b generates a power supply for supplying the second motor driver 82 (hereinafter referred to as a drive power supply). Here, examples of the types of the motor power supply device 90a and the drive power supply device 90b include a dropper power supply and a switching power supply.

[Motor power supply wiring and drive power supply wiring]
The motor power supply wiring 91 is a wiring connecting the output of the motor power supply 90a and the interface IF1 of the printed circuit board P1, and the motor power output from the motor power supply 90a is applied. The motor power is applied to the second fan motor 81 of the second fan motor device 8 via the harness L1. Accordingly, the motor current Im that is passed through the second fan motor 81 flows on the motor power supply wiring 91.

  The drive power supply wiring 92 is a wiring connecting the output of the drive power supply 90b and the interface IF1 of the printed circuit board P1, and the drive power output from the drive power supply 90b is applied. The driving power is applied to the second motor driver 82 of the second fan motor device 8 via the harness L2. Therefore, the drive current Id that is energized to the second motor driver 82 flows on the drive power supply wiring 92.

[Current leveling section]
The current leveling unit 93 levels the driving current Id before flowing on the GND wiring 94, specifically, the driving current Id flowing on the driving power supply wiring 92. Such a current leveling unit 93 includes a filter circuit including a resistor R1 and a capacitor C1. The resistor R1 is connected in series on the drive power supply wiring 92, and the capacitor C1 is connected to the drive power supply wiring 92 in parallel with the resistor R1. More specifically, one end q1 of the capacitor C1 is connected to the downstream side of the driving current Id with respect to the resistor R1 in the driving power supply wiring 92, and the other end q2 is connected to the GND wiring 94.

  Here, the resistance value of the resistor R1 and the capacitance value of the capacitor C1 are determined as follows, for example. First, in the drive current Id ′ during rotation of the second fan motor 81 when the current leveling unit 93 is not provided, the frequency f of the portion to be leveled is measured because the drive current Id ′ changes particularly. (FIG. 5). Then, the resistance value of the resistor R1 and the capacitance value of the capacitor C1 are obtained so that the frequency f becomes substantially equal to the time constant of the resistor R1 and the capacitor C1. The drive current Id ′ is leveled as shown in FIG. 6 by the filter circuit constituted by the resistor R1 and the capacitor C1 thus determined.

[GND wiring]
The GND wiring 94 is a wiring that connects the GND of the various power supply devices 90a and 90b and the interface IF1 of the printed circuit board P1, and is connected to the GND of the second fan motor device 8 via the harness L3. Accordingly, the motor current Im energized to the second fan motor 81 and the drive current Id leveled by the current leveling unit 93 and energized to the second motor driver 82 flow on the GND wiring 94. Hereinafter, for convenience of explanation, the current flowing on the GND wiring 94 (that is, the motor current Im and the leveled drive current Id) is referred to as a GND current Ig.

[Current detector]
The current detection unit 95 detects the GND current Ig flowing on the GND wiring 94, that is, the sum of the motor current Im and the leveled drive current Id. Such a current detection unit 95 is mainly composed of a shunt resistor Rs, an operational amplifier OP1, and the like. The shunt resistor Rs is connected in series with the GND wiring 94. More specifically, the shunt resistor Rs is connected to the downstream side of the GND current Ig from the other end q2 of the capacitor C1 in the current leveling unit 93 on the GND wiring 94. The two input terminals of the operational amplifier OP1 are connected to both ends of the shunt resistor Rs, respectively, and the output terminals are connected to the instantaneous current detector 96 and the average current detector 97. When the operational amplifier OP1 amplifies the voltage input from the input terminal with a predetermined gain, the operational amplifier OP1 outputs the amplified voltage to the instantaneous current detection unit 96 and the average current detection unit 97.

[Instantaneous current detector and average current detector]
The instantaneous current detector 96 detects the instantaneous value SA of the GND current Ig on the GND wiring 94 detected by the current detector 95, that is, the instantaneous value SA of the sum of the motor current Im and the drive current Id. The instantaneous current detection unit 96 includes two resistors R2 and R3 and one capacitor C2. The two resistors R2 and R3 are connected in series between the current detection unit 95 and the instantaneous current transmission line 98. The capacitor C2 is connected in parallel with the resistors R2 and R3. More specifically, one end of the capacitor C2 is connected between the two resistors R2 and R3, and the other end is connected to GND.

  The average current detector 97 detects the average value SB of the GND current Ig on the GND wiring 94 detected by the current detector 95, that is, the average value SB of the sum of the motor current Im and the drive current Id. The average current detection unit 97 includes two resistors R4 and R5 and two capacitors C3 and C4. The two resistors R4 and R5 are connected in series between the current detection unit 95 and the average current transmission line 99. The two capacitors C3 and C4 are connected in parallel to the resistors R4 and R5, respectively. More specifically, one end of the capacitor C3 is connected between the two resistors R4 and R5, and the other end is connected to GND. One end of the capacitor C4 is connected between the resistor R5 and the average current transmission line 99, and the other end is connected to GND.

  Here, the resistance values of the resistors R2 and R3 and the capacitance value of the capacitor C2 of the instantaneous current detection unit 96, the resistance values of the resistors R4 and R5 of the average current detection unit 97, and the capacitance values of the capacitors C3 and C4 are GND. The instantaneous value SA and the average value SB of the current Ig are determined to be detectable values. For example, the values of the resistors R2 to R5 and the capacitors C2 to C4 are the same as those of the resistors R2 and R3 and the capacitor C2 in the instantaneous current detector 96, and the resistors R4 and R5 and the capacitors C3 and C4 in the average current detector 97. Is determined to be smaller than the second time constant.

  As shown in FIG. 7, the instantaneous value SA of the GND current Ig is equal to or less than the average value SB of the GND current Ig and close to 0A (section A), or more than the average value SB of the GND current Ig. There is a certain section (section B). This is because, while the motor current Im is periodically supplied to the second fan motor 81, the drive current Id is leveled by the current leveling unit 93 to maintain a substantially constant state (that is, a state close to 0A). (FIG. 6).

(1-6) Signal Correction Device The signal correction device 10 is for correcting the output result from the current detection device 9, and is composed of a microcomputer including a memory such as a RAM and a ROM and a CPU, for example. . Such a signal correction apparatus 10 includes an A / D conversion unit 10a, an offset update unit 10b, and a correction unit 10c.

[A / D converter]
The A / D conversion unit 10a takes in a signal related to the second fan motor 81 output from the current detection device 9, samples the signal at a predetermined time interval, and performs A / D conversion. Here, the signal related to the second fan motor 81 is a signal output from the current detection device 9 when the second fan motor 81 rotates. Specifically, the motor current Im, the instantaneous value SA of the GND current Ig, and Examples include the average value SB (that is, the instantaneous value SA and the average value SB of the sum of the motor current Im and the drive current Id). The predetermined time interval at the time of sampling is appropriately determined according to the frequency of the signal captured by the A / D converter 10a.

[Offset update section]
The offset updating unit 10b updates the offset value of the instantaneous value SA based on the instantaneous value SA of the GND current Ig after A / D conversion. The offset value is a value used when the correction unit 10c corrects the average value SB of the A / D converted GND current Ig. In particular, the offset update unit 10b according to the present embodiment determines whether or not the instantaneous value SA of the A / D converted GND current Ig is included in a predetermined range X as illustrated in FIG. The offset value is updated using the instantaneous value SA of the GND current Ig determined to be included in the range X. Here, the predetermined range X is determined so as to have a predetermined width around the drive current Id to be supplied to the second motor driver 82. As described above, since the drive current Id is substantially constant at a value close to 0 A, the predetermined range X according to the present embodiment has an instantaneous value SA of the GND current Ig as shown in FIG. The range is determined to be close to 0A (FIG. 7).

  Therefore, the offset updating unit 10b according to the present embodiment is the drive current Id among the instantaneous values SA of the GND current Ig (that is, the sum of the motor current Im and the drive current Id) when the second fan motor 81 is rotating. It can be said that the determined instantaneous value SA is determined as the offset value (value Y2 in FIG. 7). The offset value determined in this way is stored in a memory (not shown) in the signal correction apparatus 10.

  Note that how the offset updating unit 10b according to the present embodiment updates the offset value will be described in detail in “(2) Offset value updating method”.

[Correction section]
The correcting unit 10c corrects the A / D converted signal related to the second fan motor 81 using the offset value updated by the offset updating unit 10b. More specifically, the correction unit 10c calculates the offset value (that is, the value in FIG. 7) from the average value SB (that is, the value Y1 in FIG. 7) of the GND current Ig A / D converted by the A / D conversion unit 10a. Y2) is subtracted. In this way, the correction unit 10c can calculate the motor current Im by correcting the average value SB of the A / D converted GND current Ig using the offset value (Im = Y2-Y1).

  Note that the signal correction apparatus 10 is connected to the control unit 11, and the motor current Im calculated by the correction unit 10c is output to the control unit 11 (FIG. 4).

(1-7) Control Unit The control unit 11 is a microcomputer including a memory such as a RAM or a ROM and a CPU. In the present embodiment, a case where the control unit 11 is provided separately from the signal correction apparatus 10 configured by a microcomputer is taken as an example. As shown in FIG. 8, the control unit 11 is connected to the four-way switching valve 12, the expansion valve 13, the compressor driver 51, and the first motor driver 71, and controls each connected device. For example, the control unit 11 performs path switching control of the four-way switching valve 12, driving control of the compressor driver 51 and the first motor driver 71, and the like.

  In particular, the control unit 11 according to the present embodiment is also connected to the second fan motor device 8 and the signal correction device 10 and controls these devices. Specifically, the control unit 11 controls the rotational speed of the second fan motor 81 based on the motor current Im output from the signal correction device 10, thereby controlling the amount of air sent from the second fan 6b to the room. I do. For example, the control unit 11 generates a control signal for turning on / off each switching element in the second motor driver 82 based on the motor current Im so that the air flow into the room is substantially constant, and the generated control signal Is output to the second fan motor device 8. Thereby, the drive voltage based on the control signal from the control unit 11 is output from the second motor driver 82 of the second fan motor device 8 to the second fan motor 81, and the second fan motor 81 rotates.

  As described above, the control unit 11 controls the rotational speed of the second fan motor 81 using the motor current Im, and controls the air volume into the room, so that, for example, the length of the pipe extending from the second air outlet 25 into the room. It is possible to keep the air volume that is easily affected by the atmospheric pressure or the like that changes depending on the size of the indoor space.

(2) Offset Value Update Method Hereinafter, a method in which the offset update unit 10b of the signal correction apparatus 10 updates the offset value will be described with reference to FIGS. As the offset value update method according to the present embodiment, the following four methods may be mentioned. Hereinafter, for convenience of explanation, the instantaneous value SA of the GND current Ig after A / D conversion captured by the offset update unit 10b is simply referred to as “signal”. 9 to 12 are flowcharts showing the flow of each of the offset value updating methods 1 to 4. FIG. 13 shows the number of signals taken by the offset updating unit 10b as the signal value (A / D value) is a distribution graph showing the horizontal axis and the number of signals at each value as the vertical axis. A solid line graph in FIG. 13 shows signals in the update methods 1 and 2, and a dotted line graph shows signals in the update methods 3 and 4.

(2-1) Offset value update method 1
Steps S1 to S3: When the second fan motor 81 is rotating (YES in S1), the offset update unit 10b starts capturing signals and starts counting the number of signal captures (S2). Then, the offset update unit 10b counts the number of captured signals for each value (S3).

  Steps S4 to S6: When the number of signal captures reaches the first predetermined number (YES in S4), the offset update unit 10b offsets the value of the largest number of signals among the number of signals counted for each value. The value is determined (S5. Specifically, the values “a0” and “b0” in FIGS. 13A and 13B) are temporarily stored in the memory. Next, the offset updating unit 10b resets the number of signal acquisitions and the number of signals for each value (S6). In step S4, when the number of signal captures is less than the first predetermined number (NO in S4), the operations after step S3 are repeated.

  Step S7: When the second fan motor 81 is rotating, the operations after Step S2 are repeated.

(2-2) Offset value update method 2
Steps S11 to S13: Steps S11 to S13 are the same as steps S1 to S3 related to the offset update method 1 described above, and thus the description thereof is omitted.

  Steps S14 to S16: When the number of signal captures reaches the second predetermined number (YES in S14), the offset update unit 10b determines at least the value of the largest number of signals among the number of signals counted for each value. The weighted average value of the signal is calculated using this and determined as an offset value (S15). For example, as shown in FIG. 13A, when the vertex of the graph (that is, the most number of signals) is located near the center of the predetermined range X, the offset update unit 10b With the A / D value “a0” as the center, the weighted average value is calculated using the A / D values “a1” and “a2” on both sides thereof and the number of these signals. Further, as shown in FIG. 13B, when the vertex of the graph is located at the end of the predetermined range X, the offset updating unit 10b determines the A / D value “b0” of the vertex of the graph and the signal The weighted average value is calculated using the number, the A / D values “b1” and “b2” near the vertex and within the predetermined range X, the number of these signals, and the like. Next, the offset updating unit 10b stores the determined offset value in the memory, and resets the number of signal captures and the number of signals for each value (S16). In step S14, when the number of signal captures is less than the second predetermined number (NO in S14), the operations after step S13 are repeated.

  Step S17: When the second fan motor 81 is rotating, the operations after step S12 are repeated.

(2-3) Offset value update method 3
Steps S21 to S23: When the second fan motor 81 is rotating (YES in S21), the offset update unit 10b starts to capture a signal (S22). Then, the offset update unit 10b counts the number of captured signals for each value (S23).

  Steps S24 to S27: When any of the number of signals counted for each value reaches the third predetermined number (YES in S24), the offset updating unit 10b sets the value of the signal that has reached the third predetermined number as an offset value. (S25. Specifically, the values “a0” and “b0” in FIGS. 13A and 13B) are temporarily stored in the memory. Next, the offset updating unit 10b resets the number of signals (S26). In step S24, when the number of signals counted for each value is less than the third predetermined number (NO in S24), the operations after step S23 are repeated. In step S27, when the second fan motor 81 is rotating, the operations after step S22 are repeated.

(2-4) Offset value update method 4
Steps S31 to S33: Steps S31 to S33 are the same as steps S21 to S23 related to the offset update method 3 described above, and thus the description thereof is omitted.

  Steps S34 to S37: When any of the number of signals counted for each value reaches the fourth predetermined number (YES in S34), the offset update unit 10b uses at least the value of the signal that has reached the fourth predetermined number. Then, a weighted average value of the signal is calculated and determined as an offset value (S35). Next, the offset updating unit 10b resets the number of signals (S36). In step S34, when the number of signals counted for each value is less than the fourth predetermined number (NO in S34), the operations after step S33 are repeated. In step S37, when the second fan motor 81 is rotating, the operations after step S32 are repeated. The calculation example of the weighted average value in the update method 4 is the same as the example described in steps S14 to S16 of the offset value update method 2, and thus the description thereof is omitted.

  The first and second predetermined numbers and the third and fourth predetermined numbers described above correspond to the time intervals at which the A / D conversion unit 10a performs sampling, such as “512 times” and “256”, for example. It is determined appropriately.

(3) Effect (A)
According to the signal correction apparatus 10 according to the present embodiment, when the second fan motor 81 rotates, the offset value is updated based on the instantaneous value SA of the A / D-converted GND current Ig that is a signal related to the motor. Based on the offset value, the GND current Ig average value SB is corrected. In the present embodiment, the motor current Im is calculated by correcting the average value SB of the GND current Ig based on the offset value. Therefore, since the correct motor current Im is output from the signal correction device 10, various controls such as the rotational speed control of the second fan motor 81 can be performed without any problem.

(B)
In the signal correction apparatus 10, since the instantaneous value SA of the GND current Ig included in the predetermined range X is used for updating the offset value, the number of instantaneous values SA used for updating the offset can be reduced. Therefore, it is possible to reduce the load on the microcomputer that functions as the offset update unit 10b. Further, the calculation time of the offset value can be shortened.

(C)
The offset update unit 10b according to the signal correction apparatus 10 can update the offset value by the offset value update method 1 described above. Specifically, the offset updating unit 10b takes in the signal (that is, the instantaneous value SA of the A / D converted GND current Ig) for the first predetermined number of times. The offset updating unit 10b counts the number of each signal value, and determines the value of the signal having the largest counted number as the offset value. Thereby, the offset value can be obtained more accurately.

(D)
Further, the offset updating unit 10b according to the signal correction apparatus 10 can update the offset value by the offset value updating method 2 described above. Specifically, the offset updating unit 10b takes in the signal (that is, the instantaneous value SA of the A / D converted GND current Ig) for the second predetermined number of times. The offset updating unit 10b counts the number for each value of this signal. Then, the offset update unit 10b calculates a weighted average value of the signal using at least the value of the signal having the largest number of counts, and determines this as an offset value. Thereby, the offset value can be obtained more accurately.

(E)
Further, the offset update unit 10b according to the signal correction apparatus 10 can update the offset value by the offset value update method 3 described above. Specifically, the offset updating unit 10b takes in a signal (that is, the instantaneous value SA of the A / D-converted GND current Ig) and counts the number of taken-in signals for each signal value. When any of the number of signals counted for each signal value reaches the third predetermined number, the offset updating unit 10b determines the value of the signal as an offset value. Thereby, the offset value can be obtained more accurately.

(F)
Further, the offset update unit 10b according to the signal correction apparatus 10 can update the offset value by the offset value update method 4 described above. Specifically, the offset updating unit 10b takes in a signal (that is, the instantaneous value SA of the A / D-converted GND current Ig) and counts the number of taken-in signals for each signal value. When any of the number of signals counted for each signal value reaches the fourth predetermined number, the offset update unit 10b calculates a weighted average value of the signal using at least the value of the signal, and offsets it. Determine as value. Thereby, the offset value can be obtained more accurately.

(G)
The signal correction device 10 can be applied as a signal correction device when the second fan motor 81 and the second motor driver 82 are built in the second fan motor device 8. When the second fan motor 81 and the second motor driver 82 are built in the second fan motor device 8, due to the structure, wiring through which the motor current Im after the second fan motor 81 is energized flows and the second motor. It is difficult to separately provide wiring through which the drive current Id after the driver 82 is energized flows. However, when the signal correction apparatus 10 according to the present invention is applied in such a case, the driving current out of the instantaneous value of the GND current Ig after A / D conversion (that is, the sum of the motor current Im and the driving current Id). Id is determined as an offset value, and this offset value is used for instantaneous value correction of the GND current Ig after A / D conversion. Therefore, the signal correction apparatus 10 can calculate the motor current Im with high accuracy by subtracting the offset value determined as the drive current Id from the instantaneous value that is the sum of the motor current Im and the drive current Id, for example. .

(H)
Further, according to the signal correction device 10, as described in (G), the motor current Im can be obtained by subtracting the drive current Id that is an offset value from the sum of the motor current Im and the drive current Id. The drive current Id that is an offset value is obtained using the offset value update methods 1 to 4 described above, and thus can be said to be an accurate value. Therefore, the signal correction apparatus 10 can obtain the motor current Im with high accuracy.

(I)
In addition, the air conditioner 1 can perform control such that the amount of air sent to the room is constant, for example, using the accurate motor current Im calculated based on the offset value by the signal correction device 10 described above. .

<Other embodiments>
(A)
In the above embodiment, the case where the offset value is updated using the instantaneous value SA included in the predetermined range X among the instantaneous values SA of the A / D converted GND current Ig has been described. However, the offset updating unit 10b may update the offset value by using all the captured instantaneous values SA without determining whether or not the instantaneous value SA is included in the predetermined range X. Also in this case, the offset value is calculated by the offset value updating methods 1 to 4 according to the above embodiment.

(B)
In the above embodiment, the case where the signal correction device 10 obtains the motor current Im of the second fan motor 81 included in the second fan motor device 8 together with the second motor driver 82 has been described. However, the signal correction apparatus according to the present invention can be applied to the case where the second fan motor 181 and the second motor driver 182 are individually provided as shown in FIG.

  In this case, the GND harness for the second fan motor 181 and the GND harness for the second motor driver 182 are often provided separately (L103a and L103b in FIG. 14). Therefore, the GND wiring in the current detection device 109 is also preferably divided into a GND wiring 194b for the second fan motor 181 and a GND wiring 194a for the second motor driver 182. Since only the motor current Im flows through the GND wiring 194b, the current detection unit 195 is provided so as to be able to detect the motor current Im flowing on the wiring 194b. Further, the current detection device 109 does not include a current leveling unit for leveling the drive current Id and a function unit for detecting the instantaneous value and average value of the GND current Ig as in the above embodiment. It has become.

  The signal correction apparatus 100 includes an A / D conversion unit 100a, an offset update unit 100b, and a correction unit 100c. The A / D conversion unit 100a performs A / D conversion on a signal related to the second fan motor 181, specifically, the motor current Im detected by the current detection unit 195. The offset update unit 100b updates the offset value based on the detection result of the current detection unit 195 after A / D conversion, and the correction unit 100c performs A / D conversion based on the updated offset value. The detection result signal of the subsequent current detection unit 195 is corrected. That is, it can be said that the offset value is a value for correcting a hardware variation related to the current detection device 109 such as the shunt resistor Rs and the operational amplifier OP1 in the current detection unit 195 with respect to the detection result of the current detection unit 195. Therefore, the correction unit 100 c can perform hardware variation correction on the detection result of the current detection unit 195, so that the signal correction device 100 can output the motor current Im with high accuracy to the control unit 11.

(C)
In the above embodiment, when the second fan motor 81 is included in the second fan motor device 8 together with the second motor driver 82, the current detection device 9 includes the current leveling unit 93, the instantaneous current detection unit 96, and the average current. The case where the detection unit 97 is provided has been described. However, the current detection unit may not include these function units. In particular, when the current detection device 9 does not include the instantaneous current detection unit 96 and the average current detection unit 97, the signal correction device 10 detects the GND current Ig itself detected by the current detection unit 95, that is, the motor current Im and the drive. The sum of the current Id is acquired. In this case, the offset update unit 10b of the signal correction device 10 determines the drive current Id as an offset value out of the sum of the motor current Im and the drive current Id, and the correction unit 10c determines the sum of the motor current Im and the drive current Id. The motor current Im is calculated by subtracting the offset value from.

(D)
In the above embodiment, as shown in steps S2 to S4 in FIG. 9 and steps S12 to S14 in FIG. 10, the signal is captured in parallel with the signal capture until the number of signal capture reaches the first or second predetermined number of times. The case where the process of counting the number of signals for each value is performed by the offset updating unit 10b has been described. However, the order of these processes is not limited to the above embodiment. For example, after the number of signal captures reaches the first or second predetermined number (S4, S14), processing for counting the number of captured signals for each value may be performed (S3, S13).

(E)
In the said embodiment, the case where the air conditioning apparatus 1 was a desiccant type external air conditioner which equips an inside with a heat exchanger was demonstrated and demonstrated to the example. However, the air conditioner according to the present invention can be applied to a desiccant air conditioner of a type in which a heat exchanger is provided separately from the air conditioner, or an air conditioner employing a system other than the desiccant.

(F)
In the above embodiment, the case where the signal correction apparatus 10 is configured by a microcomputer different from the microcomputer configuring the control unit 11 has been described. However, the signal correction apparatus 10 and the control unit 11 may be configured by a single microcomputer. In this case, it is assumed that a drive current determination program, a motor current calculation program, and various device control programs are stored in the memory of one microcomputer. Such a microcomputer functions as the signal correction device 10 or the control unit 11 by reading and executing any one of the drive current determination program, the motor current calculation program, and the various device control programs in the memory. Can do.

(G)
In the above embodiment, in order to control the air volume of the air SA after humidity adjustment sent to the room, the current detection device 9 detects the GND current Ig including the motor current Im that has passed through the second fan motor 81, and performs signal correction. The case where the apparatus 10 calculates the motor current Im from the GND current Ig has been described. However, the calculation target of the motor current Im according to the present invention may be the first fan motor 7, the compressor motor 5 or the like instead of the second fan motor 81. For example, the calculation target of the motor current Im may be both the first fan motor 7 and the second fan motor 81.

  Further, the first fan motor 7 may be included in the fan motor device together with the first motor driver 71, similarly to the second fan motor 81.

  The signal correction apparatus according to the present invention can output an accurate signal by updating the offset value of the signal related to the motor during rotation of the motor and correcting the signal related to the motor based on the updated offset value. It has the effect. Such a signal correction device can be applied to an air conditioner.

1 is a schematic plan view showing the configuration of an air conditioner according to an embodiment. The refrigerant circuit figure of the air conditioning apparatus in this embodiment. The perspective view of the 1st and 2nd heat exchanger with which an air harmony device is provided. The figure which shows the circuit structure inside the printed circuit board in which the signal correction apparatus and current detection apparatus which concern on this embodiment were mounted, and the schematic structure of the 2nd fan motor apparatus connected to this printed circuit board. The graph which shows the time-dependent change of drive current Id ', motor current Im, and GND current Ig when the current leveling part is not provided. The graph which shows the time-dependent change of the drive current Id leveled using the current leveling part, the motor current Im, and the GND current Ig. The graph which shows the time-dependent change of each of the instantaneous value and average value of GND electric current Ig. The block diagram which shows typically the structure of the air conditioning apparatus which concerns on this embodiment. The flowchart of the update method 1 of the offset value which concerns on this embodiment. The flowchart of the update method 2 of the offset value which concerns on this embodiment. The flowchart of the update method 3 of the offset value which concerns on this embodiment. The flowchart of the update method 4 of the offset value which concerns on this embodiment. (A) A distribution graph representing signals taken by the offset updating unit with the horizontal axis and vertical axis representing the A / D value and the number of signals at each value, respectively, and the vertex of the graph is near the center of the predetermined range X The graph which shows the case where it is located. (B) A distribution graph that represents the A / D value and the number of signals at each value on the horizontal axis and the signal taken by the offset update unit, respectively, with the vertex of the graph being near the lower end of the predetermined range X The graph which shows the case where it is located. The circuit configuration inside the printed circuit board on which the signal correction device and the current detection device according to other embodiment (b) are mounted, and the schematic configuration of the second motor driver and the second fan motor connected to the printed circuit board are shown. Figure.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Casing 3a 1st heat exchanger 3b 2nd heat exchanger 4 Compressor 5 Compressor motor 6a 1st fan 6b 2nd fan 7 1st fan motor 8 2nd fan motor apparatus 9 Current detection apparatus 10 Signal correction device 10a A / D conversion unit 10b Offset update unit 10c Correction unit 11 Control unit 71 First motor driver 81 Second fan motor 82 Second motor driver 90a Motor power supply device 90b Drive power supply device 91 Motor power supply wiring 92 Driving power supply wiring 93 Current leveling unit 94 GND wiring 95 Current detecting unit 96 Instantaneous current detecting unit 97 Average current detecting units R1 to R5 Resistors C1 to C4 Capacitor Rs Shunt resistor OP1 Operational amplifier Im Motor current Id Driving current Ig GND current SA GND Instantaneous value of current SB GND Average value of current

Claims (7)

A / D converters (10a, 100a) for A / D converting signals relating to the motors (81, 181);
An offset value used for correcting the A / D converted signal based on the A / D converted signal by the A / D converter (10a, 100a) when the motor (81, 181) rotates. Offset updating unit (10b, 100b) for updating
A correction unit (10c, 100c) that corrects the A / D-converted signal using the updated offset value;
With
The offset update unit (10b, 100b)
Capturing the signal A / D converted by the A / D converter (10a, 100a) a predetermined number of times,
Count the number of captured signals for each value of the signal,
The value of the signal having the largest number of counted signals is determined as the offset value, or at least the weighted average value of the captured signals is calculated based on the value of the signals having the largest number of counted signals and determines it as the offset value,
The signal is a motor current supplied to the motor (81) and a drive current supplied to a motor drive unit (82) for driving the motor (81), which is different from the motor current. And the sum
Of the sum of the motor current and the drive current as the signal, the drive current is determined as the offset value.
Signal correction device (10, 100). The offset update unit (10b, 100b)
The offset value is updated using the signal whose value is included in a predetermined range among the signals A / D converted by the A / D converter (10a, 100a).
The signal correction device (10, 100) according to claim 1. The correction unit (10c) calculates the motor current by subtracting the offset value from the sum of the A / D converted motor current and the drive current.
The signal correction device (10) according to claim 1 or 2 . A / D converters (10a, 100a) for A / D converting signals relating to the motors (81, 181);
An offset value used for correcting the A / D converted signal based on the A / D converted signal by the A / D converter (10a, 100a) when the motor (81, 181) rotates. Offset updating unit (10b, 100b) for updating
A correction unit (10c, 100c) that corrects the A / D-converted signal using the updated offset value;
With
The offset update unit (10b, 100b)
Capture the A / D converted signal by the A / D converter (10a, 100a),
Count the number of captured signals for each value of the signal,
If any of the number of signals counted for each signal value reaches a third predetermined number, the value of the signal reaching the third predetermined number is determined as an offset value, or When any of the number of signals counted for each value reaches a fourth predetermined number, a weighted average value of the captured signals is calculated based on at least the value of the signal reaching the fourth predetermined number. , determines this as the offset value,
The signal is a motor current supplied to the motor (81) and a drive current supplied to a motor drive unit (82) for driving the motor (81), which is different from the motor current. And the sum
Of the sum of the motor current and the drive current as the signal, the drive current is determined as the offset value.
Signal correction device (10, 100). The offset update unit (10b, 100b)
The offset value is updated using the signal whose value is included in a predetermined range among the signals A / D converted by the A / D converter (10a, 100a).
The signal correction device (10, 100) according to claim 4 . The correction unit (10c) calculates the motor current by subtracting the offset value from the sum of the A / D converted motor current and the drive current.
The signal correction device (10) according to claim 4 or 5 . The signal correction device (10, 100) according to any one of claims 1 to 6 ,
A fan motor (81, 181);
A fan (6b) driven to rotate by the fan motor (81, 181);
A control unit (11) for controlling the amount of air sent from the fan (6b) to the room based on the signal corrected by the correction unit (10c, 100c) of the signal correction device (10, 100);
An air conditioner (1) comprising:

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