JPH10184588A - Method for controlling fan motor and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct variation of rotation frequency caused by an individual difference of a fan motor without increasing a cost by previously correcting a current flowing in the fan motor in such a manner as that a deviation between current values obtained in comparison with current-rotation characteristics of a fan motor having no variation can be kept within an allowable range. SOLUTION: An initial adjuster 29 is adapted to correct variations of current- rotation characteristics caused by an individual difference of a fan motor 5 and previously keep deviation of the current-rotation characteristics caused by the individual difference of the fan motor within an allowable range of the current-rotation characteristics in which accurate control can be achieved. When a fan motor having ideal current-rotation characteristics is rotated in the state in which no resistance is exerted on an air blowing path, a standard current value flowing in a standard motor is compared with a detection current value flowing when the fan motor 5 to be actually incorporated and controlled is rotated in a standard state. Subsequently, a current flowing in the fan motor 5 is previously corrected in such a manner that a deviation between both the current values can be maintained within a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a fan motor for controlling the rotation of a fan.
In particular, the present invention relates to a technique for correcting variations in the number of revolutions of a fan motor due to individual differences in the fan motor.

[0002]

2. Description of the Related Art For example, a blower fan for forcibly sending combustion air to a combustion section (burner) in a hot water supply device or the like adjusts a blower amount according to a supply amount of fuel supplied to the burner. A motor control device is provided for controlling the number of revolutions of the fan motor such that complete combustion in the burner is always ensured.

[0003] In such a hot water supply apparatus, the air resistance (flow path resistance) in the combustion air passage (blast flow path) is changed by the air flowing into the ventilation flow path from the outside of the apparatus or in the ventilation flow path. Since the amount of air blown in the air flow path changes as the air flow changes under the influence of soot and the like adhering to the motor, this type of motor control device not only controls the amount of fuel that is conventionally supplied to the burner, but also The rotation control is performed in consideration of the flow path resistance.

[0004] That is, when there is a flow path resistance in the air flow path, for example, as shown in FIG. 10 (a), when the same current flows through the fan motor, there is no flow path resistance (standard state).
The number of rotations of the fan motor is lower than that of the fan motor. Moreover, the value of the flow path resistance does not always show a constant value due to its nature, but always changes depending on the amount of air flowing into the air flow path from the outside and the degree of adhesion of soot and the like, as described above. However, simply controlling the number of revolutions of the fan motor in accordance with the amount of supplied fuel does not ensure sufficient burner combustion.

[0005] Therefore, in the control of the rotation speed of the fan motor in the conventional hot water supply apparatus, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 36508, a wind speed sensor for detecting the amount of air flowing in the air flow passage is installed in the air flow passage, and based on a detection signal of the wind speed sensor, Or a device that directly detects the amount of air blown and controls the number of rotations of the fan motor based on the detection result so that a desired amount of air can be obtained.
As disclosed in JP-A-343, the flow rate is determined once, and based on the determined flow rate resistance, the number of rotations of the motor is controlled so that the amount of air flowing in the air flow path becomes a desired value. Has been proposed.

[0006]

However, as a motor actually incorporated in a water heater as a fan motor, for example, a fan motor (standard motor) having ideal characteristics as shown in FIG. In contrast to the current-rotation speed characteristics when used in a state, the fan motor actually used has a considerable variation in the current-rotation speed characteristics for each individual fan motor. Therefore, in order to accurately control the rotation speed of the motor as described above, fine adjustment means (specifically, correcting the motor characteristics so as to eliminate variations due to individual differences in current-rotation speed characteristics of each fan motor). Although it is necessary to improve, such as providing the V _R adjustment), its addition to the apparatus configuration becomes complicated when further increase in the number of parts leads to increased overall assembly process apparatus, so that the water heater There is a problem that the manufacturing cost of the device itself increases.

On the other hand, if it is attempted to control the number of rotations of the motor without correcting such motor characteristics, the flow path resistance cannot be detected properly due to variations in the motor. Therefore, in this case, due to the variation in the motor current, for example, a flow resistance that is out of actuality is detected, and the motor control device cannot appropriately control the blown air amount, and further, when it is determined that the blown air amount is insufficient or excessive. There is.
In this case, the desired air flow rate cannot be obtained, and the rotation speed of the motor is corrected to an erroneous one.Therefore, the combustion state may be deteriorated. Is a problem that cannot be ignored in device design. In particular, when the variation between the motors is larger than the required current-rotational speed margin of the motor, this becomes a very important problem.

[0008] In FIG. 10B, the range shown by hatching is the range of the characteristic variation due to the individual difference of the fan motor.

The present invention has been proposed in view of the above problems, and has as its main object to provide a motor control method and a motor control method capable of correcting variations in the number of revolutions due to individual differences of motors without increasing costs. And

In this connection, in the present invention, the cost of the power supply for driving the fan motor is reduced by performing PWM control on the fan motor using the obtained DC power obtained by rectifying and smoothing the commercial power. It is another object of the present invention to realize fan motor rotation control without being affected by fluctuations in power supply voltage.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the applicant of the present invention provides a hot water supply system in which the motor control device of the present invention is suitably used. Focusing on the rotation speed of the fan motor required to perform this operation, there is a fluctuation range of the rotation speed (combustion allowance range) which is somewhat allowable as shown in FIG. By suppressing the deviation of the current-rotation speed characteristic within the range of the combustion margin as described below, the rotation control of the fan motor can be realized without considering the variation due to the individual difference of the fan motor.

That is, in the fan motor control method according to the first aspect, in the fan motor control device for controlling the rotation speed of the blower fan, the rotation speed deviation of the blower fan due to the variation of the current-rotation speed characteristics of the fan motor. The fan-current characteristics of the fan motor without variation and the current-speed characteristics of the fan motor to be controlled.
The current flowing through the fan motor is corrected in advance so that the deviation between the two current values is determined by comparing the current value with the rotational speed characteristic so that the deviation falls within the range of the current-rotational speed characteristic that is allowed as the fan motor variation. It is characterized by the following.

Therefore, in the fan motor control method according to the first aspect, the current-
Since the current flowing through the fan motor is corrected in advance according to the variation in the rotational speed characteristics, the current of the fan motor
The rotation speed characteristic can be suppressed within a range allowed as the variation of the fan motor, and the rotation control of the fan motor can be realized without considering the individual difference of the fan motor.

According to a second aspect of the present invention, there is provided a method for controlling a fan motor, wherein the current-speed characteristic of the fan motor to be controlled is specified as a variation range of the current-speed characteristic of the fan motor to be controlled. Since the above-defined current-rotation speed characteristics are used, the current flowing through the fan motor can be uniformly corrected based on the motor specifications without checking the current-rotation speed characteristics of each motor to be controlled.

According to a third aspect of the present invention, there is provided a fan motor control device for implementing the above-described fan motor control method, comprising: voltage detection means for detecting information on a drive voltage on the fan motor side; Current detection means for detecting information on the drive current on the motor side; current calculation means for correcting and converting the current information detected by the current detection means based on the voltage information detected by the voltage detection means; and rotation of the fan motor. A rotation speed detecting means for detecting the number of rotations, and a flow path for judging a flow path resistance of a blowing flow path blown by a fan motor based on current information by the current calculating means and the rotation speed detected by the rotation speed detecting means. A resistance discriminating means and a fan motor control device for controlling the rotation of the fan motor based on the flow path resistance determined by the flow path resistance determining means. And an initial adjustment means for calculating a current correction amount for correcting the current flowing through the fan motor according to the variation of the current-rotational speed characteristic of the motor, and correcting the current flowing through the fan motor in advance based on the calculation result. It is characterized by the following.

According to a third aspect of the present invention, there is provided a fan motor control device comprising:
In a state in which the variation due to the individual difference of the fan motor is eliminated by the initial adjustment unit, a predetermined voltage (for example, AC100) is used based on the voltage detected by the voltage detection unit.
V or a voltage corresponding thereto), the current calculating means converts the current detected by the current detecting means into a current that would flow at the time. The flow path resistance determining means determines the flow path resistance of the air flow path based on the converted detection current and the rotation speed detected by the rotation speed detection means, and controls the rotation of the fan motor according to the flow path resistance. I do.

According to a fourth aspect of the present invention, there is provided a fan motor control device for performing the above-described method of controlling the fan motor for controlling the rotation of a fan motor for blowing air provided in a blowing channel. Rectifying and smoothing means for rectifying and smoothing power to output DC power, power control means for supplying DC power from the rectifying and smoothing means as drive power to the fan motor, and rotation for detecting a rotation speed of the fan motor. Number detecting means, voltage detecting means for detecting information on the driving voltage on the fan motor side, current detecting means for detecting information on the driving current on the fan motor side, and voltage information detected by the voltage detecting means. Current calculation means for converting the current information detected by the current detection means into current information that will flow when a predetermined voltage is applied to the motor side; Flow path resistance determining means for determining the flow resistance of the air flow path based on the current calculated by the current calculating means and the rotational speed detected by the rotational speed detecting means; and Means for judging an optimum air flow rate by the fan motor based on the optimum air flow rate judged by the optimum air flow rate judgment means and the flow path resistance judged by the flow path resistance judgment means. In a fan motor control device that determines the rotation speed and controls the rotation of the fan motor so that the rotation speed of the fan motor becomes an optimum rotation speed, the current flowing through the fan motor is corrected according to the variation in the current-rotation speed characteristics of the fan motor. And an initial adjusting means for calculating the amount of current correction to be performed and correcting the current flowing through the fan motor in advance based on the calculation result.

According to a fourth aspect of the present invention, a predetermined voltage (for example, 100 V AC, or 100 V AC) is determined based on the voltage detected by the voltage detecting means in a state where the variation due to the individual difference of the fan motor is eliminated by the initial adjusting means. The current calculation means converts the current detected by the current detection means into a current that would flow at the time of the corresponding voltage). The flow path resistance determining means determines the flow path resistance of the air flow path based on the converted detection current and the rotation speed detected by the rotation speed detection means, and controls the rotation of the fan motor according to the flow path resistance. I do. Further, the optimum air flow amount determining means determines the optimum air flow amount based on the combustion amount of the combustion section, and controls the rotation of the fan motor based on the optimum air flow amount and the determined flow path resistance.

Further, the fan motor control device according to a fifth aspect is characterized in that, in the initial adjustment means, the corrected current value is obtained by the following equation. I ₁ ′ = [n ₂ · (I _FF −I ₁ ) / (n ₁ + n ₂ )] +
I ₁ (where I ₁ ′ represents the corrected current value, I _FF represents the current value of the fan motor having no variation, I ₁ represents the current value of the fan motor to be controlled, and n ₁ represents the current value of the fan motor to be controlled. the amount in the range allowed for the _FF, also n ₂ indicates the amount exceeding the range of I ₁ is allowed. in addition, the current correction amount is n ₂ ·
(I _FF -I ₁ ) / (n ₁ + n ₂ ). )

Accordingly, when the current value of the fan motor to be controlled is within the allowable range, n ₂ becomes 0 and no correction is performed, while the value of n ₁ is appropriately changed to obtain a variation. The allowable width can be freely changed, and more precise current correction can be performed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a water heater provided with a motor control device according to the present invention, in which a burner 2 and a heat exchanger 3 are arranged inside a casing 1 of the water heater. A sirocco fan (blowing fan) 6 driven by a fan motor 5 is installed inside a fan case 4 that is continuous with a lower side of the casing 1, and an exhaust port 7 is formed at an upper portion of the casing 1. ing.

A fuel supply pipe 8 for supplying a fuel such as gas or oil is connected to the burner (combustion section) 2, and a water supply pipe 1 for supplying water to the heat exchanger 3.
0 is connected. Valves 11 and 12 are interposed in the fuel supply pipe 8 and the water supply pipe 10, and these valves 11 and 12 are controlled by a hot water supply control unit 13.

The motor control device controls the rotation of the fan motor 5 in accordance with the amount of fuel supplied to the burner 2 and the flow resistance of the air flow path so as to ensure sufficient combustion performance in the burner 2. Rectifying and smoothing means 1
6, power control means 17, rotation speed detection means 18, current detection means 19, voltage detection means 28, duty ratio control means 20, current calculation means 21, optimum air flow rate determination means 22, flow path resistance determination means 23, optimum rotation In addition to the number determination means 24, the abnormality determination means 25, and the abnormality processing means 26 as main parts, the present invention also provides an initial adjustment means 29 for eliminating variations in the number of rotations due to individual differences of the fan motor 5 used in particular. It has.

More specifically, the motor control device includes a rectifying / smoothing means 1 for rectifying and smoothing AC power from a commercial power supply 15 of, for example, 100 VAC and outputting DC power.
6, a power control unit 17 for switching the DC power from the rectifying and smoothing unit 16 based on the control pulse and supplying the driving power to the fan motor 5, and a rotation speed detection unit 18 for detecting the rotation speed of the fan motor 5. Rectifying and smoothing means 1
6, a voltage detecting means 28 for detecting the output voltage of the rectifying / smoothing means 16, a rotational speed command signal, the rotational speed detected by the rotational speed detecting device 18 and the fan motor 5 Duty ratio control means 20 for controlling the duty ratio of the control pulse based on the flowing current so that the rotation speed of fan motor 5 becomes the command rotation speed, output current and voltage detection means detected by current detection means 19 Current calculation means 21 for calculating the current flowing through the fan motor 5 based on the detected voltage of the fan motor 5 and the detection information of both the current detection means 19 and the voltage detection means 28
An optimum air flow amount determining means 22 for determining an optimum air flow amount based on the combustion amount of the burner 2; and a fan based on the current calculated by the current calculating means 21 and the rotational speed detected by the rotational speed detecting means 18. The flow path resistance determining means 23 for determining the flow resistance of the air flow path formed by the case 4 and the casing 1, and the optimum air flow rate determined by the optimum air flow rate determining means 22 and the flow resistance determination means 23 are determined. The optimum rotation speed of the fan motor 5 is determined based on the flow path resistance and the rotation speed command signal is supplied to the duty ratio control means 20 so that the rotation speed of the fan motor 5 becomes the optimum rotation speed. Means 24, an abnormality determining means 25 for determining an abnormality of combustion based on the flow path resistance determined by the flow path resistance determining means 23, and the abnormality determining means 25 determines that the combustion is abnormal. Together it outputs a stop signal to the water heater controller 13 and an abnormality processing unit 26 for stopping the combustion of the burner 2 to come, and a initial adjustment means 29 described above.

The duty ratio control means 20, the current calculation means 21, the optimum air flow rate determination means 22, the flow path resistance determination means 23, the optimum rotation speed determination means 24, the abnormality determination means 25, the abnormality processing Means 26 and initial adjustment means 29
Is realized by the microcomputer 27. The microcomputer 27 controls the entire combustion device.

FIG. 2 is a circuit block diagram of a drive unit of the fan motor 5, and the drive unit mainly includes a motor drive IC 3
1. This motor drive IC 31
Terminals 31a to 31e are provided, and power control means 17 and rotation speed detecting means 18 are mounted.

The power control means 17 includes: a motor driver 32 for supplying drive power to each coil of the fan motor 5;
A PWM variable speed circuit 33 for switching the drive power supplied to the fan motor 5 by the motor driver 32; The rotation number detecting means 18 is provided for the fan motor 5.
A rotation logic 35 for calculating the number of rotations of the fan motor 5 based on a detection signal from a Hall IC 34 including a plurality of Hall elements built in the motor, and a rotation number pulse corresponding to the number of rotations calculated by the rotation logic 35 are generated. And a rotation speed pulse generation circuit 36 that performs the rotation.

The driving power from the rectifying / smoothing means 16 is input to the terminal 31a.
Is supplied to the motor driver 32. DC power from the auxiliary power supply 37 is input to the terminal 31b, and this DC power is supplied to each part of the motor drive IC 31 as power. A control voltage is input to the terminal 31c from the duty ratio control unit 20, and the control voltage is
Is supplied to the PWM variable speed circuit 33. From the terminal 31d, a rotation speed pulse is output from the rotation speed pulse generating circuit 36 of the rotation speed detecting means 18, and this rotation speed pulse is supplied to the duty ratio control means 20. The terminal 31e is
This is a ground terminal.

The rectifying / smoothing means 16 is realized by, for example, a full-wave rectifier composed of a diode bridge and a smoothing circuit composed of a capacitor. Output power. The power control means 17 performs rectification / smoothing means 1 based on a control pulse whose duty ratio is controlled in accordance with a control voltage from the duty ratio control means 20.
6 by switching the DC power from the fan motor 5
As driving power.

That is, the DC drive power supplied to the fan motor 5 is PWM-controlled by the power control means 17. The rotation speed detecting means 18 detects the rotation of the fan motor 5 based on a detection signal from a rotation detection sensor including a Hall IC 34 including a plurality of Hall elements built in the fan motor 5.
The rotation number of the fan motor 5 is supplied to the duty ratio control means 20 and a rotation signal corresponding to the rotation of the rotation element of the fan motor 5 is supplied to the power control means 1.
7

The current detecting means 19 includes a current detecting element 29 such as a resistor or a current transformer, and detects the output current of the rectifying / smoothing means 16. Voltage detecting means 28
Detects the output voltage of the rectifying / smoothing means 16. The duty ratio control unit 20 adjusts the control voltage so that the rotation speed of the fan motor 5 becomes the command rotation speed, and supplies the control voltage to the power control unit 17.

The fan motor 5 is a three-phase brushless motor, more specifically, a permanent magnet type synchronous motor.
In this embodiment, it is used to drive the sirocco fan 6 of the combustion device.

FIG. 3 is a circuit block diagram of the power control means 17. This power control means 17 includes a triangular wave transmission circuit 41, a comparator 42, a three-phase distribution circuit 43, and transistors TR1 to TR6. ing. Components not directly related to the present invention, such as diodes for protecting the transistors TR1 to TR6 and circuits for detecting and protecting overcurrents flowing through the coils 5a to 5c of the fan motor 5, are illustrated and described. Is omitted.

The triangular wave oscillation circuit 41 has a frequency of, for example, 20 kHz.
Outputs a triangular wave with a period of. The comparator 42 is composed of an operational amplifier, and controls the voltage of the triangular wave from the triangular wave transmission circuit 41 and the control voltage V _S from the duty ratio control means 20.
Compared bets, control voltage V _S is turned on when it is equal to or higher than the voltage of the triangular wave, the control voltage V _S is turned off when less than the voltage of the triangular wave, and outputs a control pulse of the period 20 KHz.

That is, the duty ratio of the control pulse changes according to the control voltage V _S from the duty ratio control means 20. The three-phase distribution circuit 43 responds to the rotation signal from the rotation speed detecting means 18 by using the upper transistor T
R1 to TR3 and the lower transistor T
One of R4 to TR6 is selectively turned on.
For example, when the transistors TR1 and TR5 are on,
A drive current flows from the coil 5a of the fan motor 5 to the coil 5b.

Therefore, the rotation of the fan motor 5 is continued by sequentially switching the direction of the current and the coils 5a to 5c through which the current flows according to the rotational position of the rotor of the fan motor 5. Further, the three-phase distribution circuit 43 turns on / off a transistor to be turned on among the transistors TR <b> 4 to TR <b> 6 on the lower stage according to a control pulse from the comparator 42. That is, the three-phase distribution circuit 43
Changes the drive power supplied to the fan motor 5 to PWM according to the control voltage V _S from the duty ratio control means 20.
Control.

Here, the operation of the power control means 17 will be briefly summarized. The AC power from the commercial power supply 15 is rectified and smoothed by the rectification and smoothing means 16 and is supplied to the fan motor 5 via the power control means 17. It is supplied as drive power. At this time, the drive power supplied to the fan motor 5 is controlled so that the rotation speed of the fan motor 5 becomes the command rotation speed by performing the PWM control by the power control unit 17.

Now, as shown in FIG. 4, the maximum voltage of the triangular wave from the triangular wave transmission circuit 41 is V _H , the minimum voltage is V _L, and the control voltage from the duty ratio control means 20 is V _S
When the control pulse which is the output of the comparator 42, as shown in FIG. 5, the control voltage V _S is turned on when the above voltage of the triangular wave, the control voltage V _S is turned off when less than the voltage of the triangular wave , And a pulse train having the same cycle as the triangular wave.

Then, since the three-phase distribution circuit 43 applies the control pulse from the comparator 42 to the base of the transistor to be turned on among the lower transistors TR4 to TR6, the driving power of the fan motor 5 is reduced by the control pulse. And the driving power corresponding to the duty ratio of the control pulse is supplied to the fan motor 5.

Next, the initial adjusting means 29 will be described. The initial adjusting means 29 is for correcting the variation of the current-rotational speed characteristic due to the individual difference of the fan motor 5 and for controlling the rotation of the fan motor 5 without considering the individual difference. The deviation of the current-rotational speed characteristic due to the individual difference is suppressed in advance within the allowable range of the current-rotational speed characteristic that enables accurate control.

That is, in the initial adjusting means 29, as shown in FIG. 6 (a), for example, a fan motor (hereinafter referred to as a standard motor) 5 'having ideal current-rotational speed characteristics is supplied to the air flow path. A standard current value flowing through the standard motor 5 'when rotated in a state where there is no resistance (standard state), and a fan motor (hereinafter referred to as a control target motor) 5 "which is actually incorporated in the motor control device and controlled. Is compared with a detected current value flowing through the control target motor 5 ″ when the motor is rotated in the standard state, and a deviation between the two current values is obtained, and the fan is set in advance so that the deviation is within a predetermined value described later. This is for correcting the current flowing through the motor 5 ″.
The motor current required to control the motor with higher accuracy than the variation in the current-rotational speed characteristics of each motor
If the allowable range of the rotational speed characteristic is narrower, it is necessary to make a correction so that the current-rotational speed characteristic of the motor falls within the allowable range.

More specifically, when the present invention is used for controlling a fan motor of a hot water supply apparatus, in order to sufficiently maintain the combustion performance of the burner 2, it is necessary to control the combustion amount (fuel supply amount) of the burner 2. The rotation speed of the fan motor 5 is set in advance in advance. However, since the rotation speed of the fan motor 5 thus set has a fluctuation range that is allowed to some extent as shown in FIG. The value is set so as to correct the characteristics of the fan motor within the maximum allowable range for the set rotation speed of the fan motor 5.

Here, an example of the operation of correcting the detected current value I ₁ in the initial adjusting means 29 will be described with reference to FIG. In FIG. 6 (b), the current of the standard motor 5'-
The rotation speed characteristic is indicated by a solid line, and the motor 5 ″ to be controlled before the correction is performed.
Is shown by a two-dot chain line, and the corrected current-rotation speed characteristic (the maximum width of the current-rotation speed characteristic allowed while ensuring accuracy) of the controlled motor 5 ″ is shown by a one-dot chain line. The current rotation speed of the control target motor 5 ″ is set to N ₁
Assuming that the detected current value at this time is I ₁ and the standard current value is I _FF , the current value I ₁ ′ after the current correction by the initial adjustment means 29 is obtained by the following formula.

[0045]

(Equation 1)

However, in this equation (1), n ₁ is I
The amount of the acceptable range for the _FF Also n _2, indicates the amount exceeding the range of I ₁ is permitted. Therefore, here, n ₁ + n ₂ is a deviation between the standard current I _{FF at} the rotation speed N ₁ of the standard motor and the actual detected current I ₁ . Then
If the motor in question is within the allowable range of characteristics,
When n ₁ = 0 and I ₁ ′ = I ₁ , the variation is not actually corrected, and the motor is controlled based on the detected current.
On the other hand, if the characteristics of the motor in question exceeds the acceptable range, the current in the detection current I ₁ tolerance - characteristic such that the rotational speed characteristic has been converted. And
The correction of the variation by the initial adjustment means 29 is performed at the time of initial setting of the apparatus, preferably at the time of shipment of the apparatus.

Next, the operation of the fan motor control device of the present invention specifically used for a hot water supply device will be described with reference to the flowchart shown in FIG.

When an operation command is input from a remote controller (not shown), hot water supply control unit 13 controls valves 11, 12
And an igniter (not shown) to start the ignition operation, and outputs a signal corresponding to the combustion amount of the burner 2, that is, the valve opening amount of the valve 11 to the optimum air flow amount determining means 22. As a result, the optimum blowing amount determining means 22 calculates the optimum blowing amount according to the combustion amount of the burner 2 based on the signal from the hot water supply control unit 13 (step S1).

At this time, the fan motor 5 has not yet been rotated, and the result of the discrimination by the flow path resistance discriminating means 23 has not been supplied to the optimum air flow rate discriminating means 22, so that the optimum rotational speed discriminating means 24 is set in advance. Done for example 3 per minute
A rotation speed command signal corresponding to the initial rotation speed of about 000 rotations is output to the duty ratio control means 20 (step S).
2). Thus, the duty ratio control means 20 controls the control voltage V such that the fan motor 5 rotates at the initial rotation speed.
_S is supplied to the power control means 17. As a result, the power control unit 17 controls the driving power by the PWM method, and drives the fan motor 5 to rotate at the initial rotation speed.

Next, the abnormality determining means 25 starts a built-in timer (step S3).

Next, the current detecting means 19 is connected to the fan motor 5
And the supply voltage is detected by the voltage detection means 28 (step S4). The rotation speed detecting means 18 detects the rotation speed of the fan motor 5 based on the detection signal from the Hall IC 34 of the fan motor 5 (Step S5).

Next, the current calculating means 21 calculates the current flowing through the fan motor 5 for appropriately obtaining the flow path resistance from the output current of the rectifying / smoothing means 16 detected by the current detecting means 19 (step 6). .

That is, if there is no voltage fluctuation of the commercial power supply 15 and the output voltage of the rectifying / smoothing means 16 is always constant,
There is little need to correct the output current of the rectifying and smoothing means 16 detected by the current detecting means 19, but in reality, for example, in the case of a commercial power supply 15 of AC 100 volts, the current actually fluctuates to 75 to 120 volts. In order to correct the difference between the change in the output current of the rectifying / smoothing means 16 and the current flowing through the fan motor 5 due to the fluctuation, the current calculating means 21 calculates the fan motor 5 from the output current of the rectifying / smoothing means 16.
It is necessary to calculate the current flowing through the rectifier and correct the actually detected output current of the rectifying / smoothing means 16. Here, in order to make the description easier to understand, first, a description will be given of the flow path resistance determining operation when it is not necessary to correct the output current of the rectifying / smoothing means 16.

That is, as shown in FIG. 8, the relationship between the rotation speed N of the fan motor 5 and the current I flowing through the fan motor 5 is such that data relating to the flow path resistance is stored in a memory or the like in advance. Thus, the flow path resistance Φ can be determined from the rotation speed N and the current I. For example, if the current I becomes I ₀ when the rotation speed N is N ₁ , or if the current I becomes I ₁ when the rotation speed N is N ₂ , it can be determined that the flow path resistance Φ is Φ _1. If the current I becomes I ₀ when the rotational speed N is N ₀ , it can be determined that the flow path resistance Φ is Φ ₀ .

Note that Φ ₀ is smaller than Φ ₁ . The flow path resistance Φ can be experimentally obtained, for example, by the following equation 2, assuming that the rotation speed of the fan motor 5 is N and the current flowing through the fan motor 5 is I. Where g (N), f
(N) is a function of the rotation speed N. Alternatively, it can be obtained by the following equation 3 as another experimental equation.

[0056]

(Equation 2)

[0057]

(Equation 3)

Next, the operation in which the current calculating means 21 corrects the current detected by the current detecting means 19 will be described. As long as a constant voltage is always supplied from the commercial power supply 15, the flow path resistance can be determined by the above method. However, since the voltage of the commercial power supply 15 fluctuates in practice, it can be determined only by the above method. However, correction by the current calculation means 21 is required.

That is, when the voltage of the commercial power supply 15 fluctuates, the relationship between the rotational speed N of the flow path resistance Φ and the current I shown in FIG. 8 fluctuates, for example, as shown in FIG. In this case, a method is also conceivable in which the relationship data indicating the flow path resistance shown in FIG. 8 is stored in advance for each voltage value of the commercial power supply in consideration of the voltage fluctuation of the commercial power supply 15 in advance. However, in this case, since a very large memory capacity is required, the reference data of the flow path resistance as a reference as shown in FIG. The same effect can be obtained by performing the correction by reducing the memory.

Next, the correction performed by the current calculation means 21 will be described in detail. There are two types of correction: voltage correction and motor characteristic correction. The value of the output voltage of the rectifying / smoothing means 16 detected by the voltage detecting means 28 is V _0, and the value of the output current of the rectifying / smoothing means 16 detected by the current detecting means is I ₀ . Further, the voltage at the time of acquiring data indicating the relationship with the flow path resistance held in the memory as shown in FIG.
0 V), and I is a correction current that would correspond to the voltage V.

Here, when the electric / mechanical work conversion efficiency is considered to be 100% from the standpoint of the work load of the fan motor 5, the following equation 4 is established.

[0062]

(Equation 4)

Therefore, the correction current that will flow when the AC 100 V commercial current is supplied can be obtained by the following equation (5).

[0064]

(Equation 5)

As described above, in step S6, the current I flowing through the fan motor 5 is calculated by the current calculation means 21 to correct the output current I ₀ detected by the current calculation means 19, and in step S7, the correction is performed. Since the flow path resistance is calculated by the flow path resistance determining means 23 using the obtained current I, the flow path resistance can be accurately obtained regardless of the voltage fluctuation of the commercial power supply 15.

Next, correction is performed based on the motor characteristic variation correction means set by the initial adjustment means 29, that is, on the basis of the above equation (1). At this time, the corrected current I ₁ ′ = the detected current I (because n ₂ = 0) if the characteristics of the motor are within the allowable range of variation in advance.
, And are not substantially corrected. On the other hand, when the characteristics of the motor exceed the allowable range of the variation, the characteristics are set so as to be within the allowable range of the characteristics based on the equation (1) so that the blown air amount can be correctly detected based on the relationship of FIG. Will be corrected.

The flow path resistance determining means 23 determines whether the current corrected by the current calculating means 21 and the rotational speed detecting means 18
Then, the flow path resistance Φ of the blower flow path in the fan motor 5 and the casing 1 is determined based on the relationship shown in FIG.

Next, the abnormality determination means 25 determines whether or not the flow path resistance Φ determined by the flow path resistance determination means 23 falls between a predetermined lower limit value ΦL and a predetermined upper limit value ΦH. (Step S8). In other words, when the flow path resistance Φ is out of the range between the lower limit value ΦL and the upper limit value ΦH, it is not possible to secure an appropriate air flow even if the rotation speed of the fan motor 5 is controlled. Need to
If the flow path resistance Φ is between the lower limit value ΦL and the upper limit value ΦH, an appropriate amount of air can be secured by controlling the number of revolutions of the fan motor 5, so that it can be determined that the condition is normal. The first quadrant in FIG. 8 shows the relationship between the current I flowing through the fan motor 5, the number of revolutions N, and the flow path resistance Φ.
The fourth quadrant represents the relationship among the number of revolutions N of the fan motor 5, the air flow rate Q, and the flow path resistance Φ.

If the flow path resistance Φ is between the lower limit ΦL and the upper limit ΦH, the abnormality determining means 25 determines that the flow is normal and clears the built-in timer (step S).
9). As soon as this timer is cleared, it restarts and resumes timing operation.

Next, the optimum rotational speed determining means 24 determines the optimum rotational speed based on the flow path resistance Φ determined by the flow path resistance determining means 23 and the optimum air flow rate determined by the optimal air blowing determining means 22. The calculation is performed (step S10), and the rotation number command signal is output to the duty ratio control means 20. That is, as shown in FIG. 8, the relationship between the rotation speed N of the fan motor 5 and the air flow rate Q changes with the flow path resistance Φ.
The optimum rotation speed is determined according to the flow path resistance Φ so that the optimum air volume can be obtained. In addition to obtaining the optimum rotation speed Ns based on FIG. 8 itself, the optimum rotation speed is represented by Q _0, and the reference rotation speed determined based on the reference flow path resistance Φ ₀ and the combustion amount is _denoted by Ng. For example, it is obtained by an empirical formula of the following Expression 6. Alternatively, it can also be obtained by the following equation 7 as another experimental equation.

[0071]

(Equation 6)

[0072]

(Equation 7)

Thus, the duty ratio control means 20
The fan motor 5 is set to the optimum rotation speed based on the rotation speed command signal corresponding to the optimum rotation speed calculated by the optimum rotation speed determination unit 24 and the actual rotation speed from the rotation speed detection unit 18. and it outputs the control voltage V _S to the power control unit 17 (step S11).

Thus, the power control means 17 switches the DC power supplied to the fan motor 5 based on the control voltage from the duty ratio control means 20, and drives the fan motor 5 so that the fan motor 5 has the optimum rotation speed. .

Next, the optimum air blowing amount determining means 22 determines whether or not the combustion amount has been changed based on the signal from the hot water supply control unit 13 (step S12). It is determined whether or not an instruction to end the operation has been input from the remote controller (step S13), and if not, the process returns to step S5. If so, the routine ends.

If it is determined in step S12 that the optimum amount of air has been changed, the flow returns to step S1.

In step S8, the abnormality determining means 25
However, if it is determined that the flow path resistance Φ does not fall between the predetermined lower limit ΦL and the upper limit ΦH, the abnormality determination means 25 further determines whether the built-in timer has expired ( Step S14) If the time is not up, the process proceeds to step S10. If the time is up, an error is output to the abnormality processing means 26. That is,
Since the flow path resistance Φ may constantly change due to the influence of wind or the like, it is determined that the state is abnormal only when the flow path resistance Φ has an abnormal value for a predetermined time or more.

Next, the abnormality processing means 26 outputs a stop signal to the hot water supply control unit 13 to stop the combustion of the burner 2 by inputting a signal indicating the abnormality from the abnormality determination means 25, for example. (Step S1)
5) End the routine.

As described above, according to the present invention, the rectifying and smoothing means 16 for rectifying and smoothing the AC power to output the DC power, and the DC power from the rectifying and smoothing means 16 for switching the DC power from the fan based on the control pulse. 5, a power control unit 17 for supplying drive power to the motor 5, a rotation speed detection unit 18 for detecting the rotation speed of the fan motor 5, a current detection unit 19 for detecting the output current of the rectifying and smoothing unit 16, a rotation speed command signal, When a predetermined voltage is applied based on the output current detected by the current detection unit 19 and the information on the voltage detected by the voltage detection unit 28 based on the rotation speed detected by the rotation speed detection unit 18 And a current calculating means 21 for calculating the current flowing through the fan motor 5, so that the current flowing through the fan motor 5 is It can be known, therefore it is possible to properly determine the flow resistance.

The present invention is not limited to the above embodiment, but can be variously modified. (1) That is, the equation of the current correction in the initial adjustment unit 29 shown in the above embodiment is not necessarily the equation (1).
The present invention is not limited to this, and can be appropriately changed within the scope of the concept of the present invention. For example, in FIG. 6B and Expression (1), the current-rotational speed characteristics of the motor are adjusted to the characteristics having the largest variation in the allowable range, but may be adjusted with some margin. Specifically, it can be expressed by Equation 8 below.

[0081]

(Equation 8)

Where n ₁ ′ = n ₁ + α (margin value)

(2) In the above embodiment, the detection position of the current detection means 19 is arranged at the output position of the rectification and smoothing means 16, but the present invention is not limited to this position. It may be provided between the motors 5 or on the ground side of the motor 5. In addition, if possible, it is not necessary to consider the power consumption of the power control means 17, and therefore, it is also a desirable detection method that the detection is performed directly before and after the motor 5. In addition, any other position may be used as long as information on the current can be detected.

(3) In the above embodiment, the detection position of the voltage detection means 28 is arranged at the output position of the rectifying / smoothing means 16, but the voltage of the commercial power supply 15 is not limited to this position. Monitoring may be performed. Any other position may be used as long as information on the voltage can be detected. However, when the detection position by the current detection unit 19 and the detection position by the voltage detection unit 28 are set to different positions, the above equation (3) is not always applied as it is. Therefore, the correction of the current can be realized by a calculation formula or a relationship based on an experimental value.

(3) In the above embodiment, in the flowchart shown in FIG. 6, when the process is not finished in step S13, the process returns to step S5. However, the process may return to step S4. In this case, the operations of steps S4 to S15 are performed when the power supply 15 fluctuates even when there is no change in the blower amount.

(4) In the above embodiment, the PWM type fan motor control device has been mainly described. However, the PAM type fan motor control device or any other type of fan motor control device may be used. Of course, it can be applied.

(5) In the PWM method, the driving IC 3
If the current amount such as 1 is considered, more accurate calculation can be performed.

(6) In the above-described embodiment, an example in which the current calculating means 21 corrects and calculates the current detected by the current detecting means 19 using the equation (5) has been described. However, this is merely an example. Things. It goes without saying that other correction calculations may be used. Actually, the correction calculation method may be different depending on the characteristics of the motor used, the detection position of the current detection unit 19, and the detection position of the voltage detection unit 28.

(7) In addition, as shown in the above embodiment,
Equations (2), (3), (6) and (7) are examples,
Of course, it is not limited to this.

(8) In the above embodiment, for example, at the time of shipment, constants n ₁ and n ₂ for correcting variations in motors are obtained by the initial adjustment means 29, and the motors are individually corrected. However, the variation width of the current-rotational speed characteristic of the motor to be used is generally determined by the specification as the error width of the motor itself, and in such a case, the variation width corresponds to the required accuracy. It can be determined uniformly by the allowable width. That is,
The variation width of the motor specifications is n ₁ + n _2, and the variation width of the motor specifications exceeding the allowable width is n ₂ . In this manner, the current-rotational speed characteristic can be set within the margin of the required accuracy uniformly based on the specifications of the motor without individually inspecting and adjusting each motor. When the correction is performed by such a method, n ₁ and n ₂ determined from the above-mentioned variation width of the motor specification and the allowable width are uniformly stored in the initial adjustment means 29. As a result, there is an effect that the current-rotational speed characteristics of the motor can be uniformly corrected without detecting the individual current-rotational speed characteristics of the motor. Therefore, the initial adjustment unit 29 may be configured to store the correction constant uniformly as described above. Note that, in this case, the correction is performed even when the value is already within the allowable range, and the standard characteristics are brought closer.

(9) Further, in the above-described embodiment, the variation correction of the characteristics of the motor is performed in step S6. However, once the adjustment is performed by the initial adjustment unit 29, the same correction is performed. The correction may be performed simultaneously with the current detection, or the detected current may be corrected. Substantially, the correction may be made when the flow path resistance is calculated based on FIG. 8 or the actual air flow rate is calculated.

[0092]

As described above in detail, according to the fan motor control method of the present invention, the current-rotation speed characteristics of the fan motor having no variation and the current-rotation speed characteristics of the fan motor to be controlled are obtained. And by correcting the current flowing through the fan motor in advance based on the difference between the current values of the two, the variation due to the individual difference in the current-speed characteristics of the fan motor to be controlled is kept within an allowable range. Therefore, compared to the case where the current-speed characteristic itself of the fan motor is corrected by providing a volume for adjustment, it is possible to eliminate the variation due to individual differences with a simple configuration of the apparatus and without increasing the cost. it can.

At this time, the current-rotational speed characteristic of the fan motor to be controlled is determined by using the current-rotational speed characteristic defined in the specification as a variation range of the current-rotational speed characteristic of the fan motor. The current flowing through the fan motor can be uniformly corrected based on the motor specifications without checking the current-rotation speed characteristics of the individual motors to be controlled, thereby reducing the time and effort required for initial adjustment, thereby further reducing costs. Can be achieved.

Further, according to the fan motor control device of the present invention, it is possible not only to eliminate variations due to individual differences in fan motors without increasing the cost as described above,
Even when the power supply voltage fluctuates, the flow path resistance of the air flow path can be determined, so that appropriate rotation control can be performed according to the state of the flow path resistance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hot water supply device including a fan motor control device according to the present invention.

FIG. 2 is a circuit block diagram of a motor drive unit of the control device.

FIG. 3 is a circuit diagram of power control means provided in the control device.

FIG. 4 is a waveform diagram of a triangular wave obtained by a triangular wave oscillation circuit provided in the control device.

FIG. 5 is a waveform diagram of a drive voltage supplied to a fan motor controlled by the control device.

FIG. 6 is an explanatory view showing an outline of a control method of a fan motor according to the present invention. FIG. 6 (a) shows a relationship between a standard characteristic of the fan motor, a variation range, and an allowable range capable of securing detection accuracy. FIG. 6B shows a method of correcting the current flowing through the fan motor.

FIG. 7 is a flowchart illustrating the operation of the fan motor control device according to the present invention.

FIG. 8 is an explanatory diagram showing a relationship among a current flowing through a fan motor controlled by the control device, a rotation speed, and an air flow rate.

FIG. 9 is an explanatory diagram showing a relationship between a current detected by current detection means of the control device and a rotation speed of a fan motor.

10A and 10B are characteristic diagrams showing current-rotation speed characteristics of a fan motor. FIG. 10A shows a characteristic change when a blower flow path has a flow path resistance, and FIG. The range of variation is shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Burner (combustion part) 3 Heat exchanger 4 Fan case 5 Fan motor 6 Sirocco fan (Blower fan) 7 Exhaust port 8 Fuel supply pipe 10 Water supply pipe 11, 12 Valve 13 Hot water supply control part 15 Commercial power supply 16 Rectification smoothing Means 17 Power control means 18 Rotation speed detection means 19 Current detection means 20 Duty ratio control means 21 Current calculation means 22 Optimal air flow rate determination means 23 Flow resistance determination means 24 Optimal rotation number determination means 25 Abnormality determination means 26 Abnormality processing means 27 Microcomputer 28 voltage detecting means 29 initial adjusting means

Claims (5)

[Claims] 1. A fan motor control device for controlling the rotation speed of a blower fan, the method comprising reducing a rotation speed deviation of the blower fan due to a variation in a current-rotational speed characteristic of the fan motor. The current-rotational speed characteristics of the motor and the current-rotational speed characteristics of the fan motor to be controlled are compared to determine a difference between the current values of the two. A method for controlling a fan motor, wherein a current flowing through the fan motor is corrected in advance so as to fall within a characteristic range. 2. A method according to claim 1, wherein the current-rotational speed characteristic of the fan motor to be controlled is a current-rotational speed characteristic defined in specifications as a variation range of the current-rotational speed characteristic of the fan motor to be controlled. Claim 1 characterized by the following:
3. The method for controlling a fan motor according to claim 1. 3. An apparatus for implementing the method for controlling a fan motor according to claim 1 or 2, wherein voltage detection means for detecting information on a drive voltage on the fan motor side, and a drive current on the fan motor side. Current detecting means for detecting information about the fan motor, current calculating means for correcting and converting the current information detected by the current detecting means based on the voltage information detected by the voltage detecting means, and rotation for detecting the rotation speed of the fan motor. Number detection means, flow path resistance determination means for determining the flow resistance of the air flow path blown by a fan motor based on the current information by the current calculation means and the rotation speed detected by the rotation speed detection means, In the fan motor control device for controlling the rotation of the fan motor based on the flow path resistance determined by the flow path resistance determination means, A fan correcting means for calculating a current correction amount for correcting a current flowing through the fan motor according to the variation in the characteristics, and an initial adjusting means for correcting the current flowing through the fan motor in advance based on the calculation result. Motor control device. 4. An apparatus for implementing the method of controlling a fan motor according to claim 1 or 2 in the rotation control of a fan motor for blowing provided in a blowing channel, wherein the AC power is rectified and smoothed. Rectifying and smoothing means for outputting DC power to the DC motor, power control means for supplying DC power from the rectifying and smoothing means as drive power to the fan motor, and a rotational speed detecting means for detecting a rotational speed of the fan motor; Voltage detection means for detecting information on the drive voltage on the fan motor side, current detection means for detecting information on the drive current on the fan motor side, and the current detection means based on the voltage information detected by the voltage detection means Current calculation means for converting the detected current information into current information that will flow when a predetermined voltage is applied to the motor side; and Flow path resistance determining means for determining the flow path resistance of the air flow path based on the calculated current and the rotation speed detected by the rotation speed detection means; An optimal air flow rate determining means for determining an air volume, and an optimal rotation speed of the fan motor based on the optimal air flow rate determined by the optimal air flow rate determining means and the flow path resistance determined by the flow path resistance determining means. In a fan motor control device that determines and controls the rotation of the fan motor so that the rotation speed of the fan motor becomes an optimum rotation speed, a current correction that corrects a current flowing through the fan motor according to a variation in a current-rotation speed characteristic of the fan motor. A fan motor control device comprising: an initial adjusting unit that calculates an amount and corrects a current flowing through the fan motor in advance based on the calculation result. 5. The fan motor control device according to claim 3, wherein the corrected current value is obtained by the following equation using the initial adjustment means. I ₁ ′ = [n ₂ · (I _FF −I ₁ ) / (n ₁ + n ₂ )] +
I ₁ (where I ₁ ′ represents the corrected current value, I _FF represents the current value of the fan motor having no variation, I ₁ represents the current value of the fan motor to be controlled, and n ₁ represents the current value of the fan motor to be controlled. the amount in the range allowed for the _FF, also n ₂ indicates the amount exceeding the range of I ₁ is allowed. in addition, the current correction amount is n ₂ ·
(I _FF -I ₁ ) / (n ₁ + n ₂ ). )