JP2001286179A - Fan motor control method and its unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve controllability of outside loads and attain sufficient protection. SOLUTION: A fan motor control unit has a rotation speed arithmetic operator 5 which calculates an existing rotation speed referring to a cycle of a position signal, a current detection circuit 6 which detects Dc current in an inverter 2a, an overload detection/speed reduction control part 7 which calculates a rotation speed instruction by making overload detection and a speed reduction arithmetic operation with the existing speed, the speed instruction supplied from the outside and the detected current as the input, a rotation speed controller 8 which calculates a duty instruction by making speed control arithmetic operation with the existing speed and the rotation speed order as the input and a drive signal generator 9 which outputs a gate signal with the position signal and the duty instruction as the input.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan motor control method and apparatus, and more particularly, to a fan motor control method and apparatus suitably applied to an air conditioner.

[0002]

2. Description of the Related Art In recent years, brushless DC motors driven by inverters have been increasingly used in fan motors used in air conditioners from the viewpoint of reducing power consumption. A brushless DC motor used for a fan motor has a good installation environment compared to a brushless DC motor used for a compressor or the like. Therefore, an inexpensive Hall sensor is usually used as a position sensor. It is driven by adopting the power distribution method.

Further, since the inverter can control the number of revolutions of the brushless DC motor according to a command regardless of the magnitude of an external load, control performance can be improved from the viewpoint of speed control.

Further, from the viewpoint of protection, the fan motor or its driver is protected by an operation of stopping when an overcurrent occurs.

A further explanation will be given.

FIG. 14 is a schematic diagram showing a conventional fan motor control device for an air conditioner to which a 120-degree conduction method is applied.

This fan motor control device is configured to switch an upper arm transistor and a lower arm transistor of each phase of an inverter main circuit according to a gate drive signal from a gate drive circuit, from a voltage type PWM (pulse width modulation) inverter. Brushless D for each phase output
It is supplied to the stator windings of the corresponding phase of the C motor, and the fan is rotated by the rotor of the brushless DC motor.

Further, inside the brushless DC motor, Hall sensors Hu, Hv, Hw arranged at every 120 degrees having a fixed phase relationship with the back electromotive voltage are provided, and these Hall sensors Hu, Hv , Hw, a position signal for each electrical angle of 60 degrees can be obtained.
Refer to the middle (B).

[0009] These position signals are supplied to a rotation speed calculation unit, for example, the current rotation speed vm is calculated from the time interval between the position signals, and a rotation speed command v * given from outside is provided.
By supplying the calculated current rotation speed vm and the calculated current rotation speed vm to the rotation speed control calculation unit, a deviation between them is calculated, a duty command D * corresponding to the calculated difference is output, and a 120-degree energization pattern creation unit is output. To supply. Since the position signal is also supplied to the 120-degree conduction pattern control unit,
By performing pattern recognition or logical operation on the position signal, a drive signal G for performing 120-degree conduction is provided.
u, Gv, Gw, Gx, Gy, Gz can be created {see (C) in FIG. 15}.

Here, the pulse width of the drive signals Gu, Gv, Gw corresponding to the upper arm transistor can be adjusted by performing pulse width modulation on the duty command D *.

Therefore, the transistors of each phase of the inverter main circuit are turned on / off by these drive signals, and a voltage is supplied to the stator winding of the brushless DC motor. By applying a voltage synchronized with the rotor position to the stator winding as described above, the brushless DC motor can be driven and the fan can be rotated.

In addition, the DC current of the inverter is detected, and when the DC current is an overcurrent, the gate drive circuit is controlled by an overcurrent protection circuit to stop the gate signal, and thus the brushless DC motor is stopped. Protection of brushless DC motors and inverters can be achieved.

More specifically, as shown in the flowchart of FIG. 16, it is determined in step SP1 whether the duty command is 0, and if it is determined that the duty command is not 0, in step SP2, , The drive signal {see FIG. 15 (C)} is generated. On the other hand, if it is determined that the duty command is 0, the process proceeds to step S
In P3, a stop signal {see (C) in FIG. 17} is generated.

When the processing in step SP2 or the processing in step SP3 is performed, the generated drive signal or stop signal is supplied to the gate drive circuit.

Further, a method has been proposed in which an output signal of a voltage command is limited at a certain limit level to protect an inverter without outputting a voltage higher than a predetermined load level (see Japanese Patent Application Laid-Open No. 10-4694).

[0016]

When the fan motor control device for an air conditioner shown in FIG. 14 is employed, protection can be provided at the time of an overcurrent, but the controllability to an external load such as a backwind is not improved. Since no consideration is given, there is a disadvantage that the heat exchange airflow in such a case cannot be set to a sufficient airflow.

When the protection method disclosed in Japanese Patent Application Laid-Open No. 10-4694 is adopted, the protection level is determined by the output voltage, so that the DC voltage varies, the motor characteristics vary, and the temperature varies. However, there is an inconvenience that the actual protection level fluctuates.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a method and apparatus for controlling a fan motor capable of improving controllability with respect to an external load and achieving sufficient protection. It is intended to provide.

[0019]

According to a first aspect of the present invention, a method of controlling a fan motor includes detecting a load applied to the fan motor when driving the fan motor by the fan control means, and detecting the detected load to be equal to or greater than a predetermined load. In response to the command speed to be supplied to the fan control means, and in response to the detected load being smaller than the predetermined load, the command speed to be supplied to the fan control means is increased. is there.

In the fan motor control method of the present invention, when the fan motor is driven by the fan control means, a load on the fan motor is detected, and after the detected load exceeds a predetermined load, the detected load becomes lower than the predetermined load. This is a method in which the command rotation speed is kept decreasing until the load decreases, and after the detected load becomes smaller than the predetermined load, the command rotation speed is kept increasing.

According to a third aspect of the present invention, there is provided a method for detecting a load by using a DC current value of a fan control means or a fan motor current value and a rotation speed of the fan motor.

According to a fourth aspect of the present invention, there is provided a fan motor control method for detecting an overload state in response to a detected load being a predetermined load or more.

According to a fifth aspect of the present invention, the fan motor control method detects the overload state in response to the current value being equal to or greater than the overload determination value indicating the overload state, and the current value indicates the overload elimination state. This is a method of detecting an overload elimination state in response to the return determination value or less.

A sixth aspect of the present invention is a method of setting at least one of an overload determination value and a return determination value in accordance with a rotation speed.

According to a seventh aspect of the present invention, at least one of the overload judging value and the return judging value is set to be larger at a higher rotation speed and smaller at a lower rotation speed.

In the fan motor control method according to the present invention, at least one of the overload judgment value and the return judgment value is set to a value at the maximum use rotation speed in response to the rotation speed being higher than the maximum use rotation speed. How to

The fan motor control method according to the ninth aspect is a method in which the overload determination value is set to a current value at a higher load at a lower rotation speed.

A tenth aspect of the present invention is a method of setting the overload determination value to a current value at a higher load as the rotation speed increases.

An eleventh aspect of the present invention is a method of setting an overload determination value according to an operation range.

A fan motor control method according to a twelfth aspect is a method of setting the overload determination value at the maximum operating speed to a value larger than the current value corresponding to the maximum load at which the fan motor should be started.

A fan motor control method according to a thirteenth aspect is a method in which a peak hold value, an average value, or an effective value of a current is adopted as the DC current value or the fan motor current value.

A fourteenth aspect of the present invention is a method of setting the degree of change in the set value of the command rotation speed to be longer than the settling time of the speed control.

The fan motor control method according to claim 15 is a method of setting the degree of decrease in the set value of the command rotation speed so that the temperature rise is lower than the temperature rise at which the fan control means is destroyed.

A fan motor control method according to a sixteenth aspect is a method in which the determination value is set for each value coarser than the rotational speed resolution, and the value at the intermediate rotational speed is determined by interpolation processing.

In the fan motor control method of the present invention, the waveform output from the fan control means is stopped in response to the command rotation speed and the actual rotation speed being equal to or less than the waveform output stop rotation speed during the rotation speed reduction operation. Is the way.

The fan motor control method according to the eighteenth aspect is a method of setting the waveform output stop rotation number according to whether the apparatus is being started or is in normal operation.

A fan motor control method according to a nineteenth aspect is a method in which the waveform output stop rotation speed corresponding to the start is set to a value lower than the waveform output stop rotation speed corresponding to the normal operation.

According to a twentieth aspect of the present invention, there is provided a method of turning off all the switching elements included in the fan control means when the waveform output is stopped.

A fan motor control method according to claim 21 is a method that employs a fan motor that drives a fan included in an air conditioner.

A fan motor control method according to claim 22 is a method in which a brushless DC motor is adopted as the fan motor.

According to a twenty-third aspect of the present invention, the fan motor control device drives the fan motor by the fan control means. The load detection means for detecting a load applied to the fan motor, and the detected load is equal to or more than a predetermined load. In response to the command, the command rotation speed to be supplied to the fan control means is decreased, and the command rotation speed to be supplied to the fan control means is increased in response to the detected load being smaller than the predetermined load. Rotation speed control means.

According to a twenty-fourth aspect of the present invention, the fan motor control device drives the fan motor by the fan control means, wherein the load detection means for detecting the load applied to the fan motor and the detected load is equal to or more than a predetermined load. After that, until the load becomes smaller than the predetermined load, the command rotational speed is continuously reduced, and after the detected load becomes smaller than the predetermined load, the command rotational speed is continuously increased. Including.

According to a twenty-fifth aspect of the present invention, in the fan motor control apparatus, the load detection means detects a load by using a DC current value of the fan control means or a fan motor current value and a rotation speed of the fan motor. It is.

According to a twenty-sixth aspect, the fan motor control device employs, as the load detecting means, a device that detects an overload state in response to the detected load being equal to or greater than a predetermined load.

A fan motor control device according to claim 27, wherein said overload detecting means detects an overload state in response to a current value being equal to or greater than an overload determination value representing an overload state, and Detects the overload elimination state in response to the return determination value indicating the overload elimination state being equal to or less than the return determination value.

A fan motor control device according to a twenty-eighth aspect employs, as the overload detection means, one that includes determination value setting means for setting at least one of an overload determination value and a return determination value in accordance with the number of revolutions. It is.

A fan motor control device according to a twenty-ninth aspect employs, as the determination value setting means, one that sets at least one of an overload determination value and a return determination value as the rotation speed increases and decreases as the rotation speed decreases. Things.

According to a thirty-fifth aspect of the present invention, in the fan motor control device, at least one of the overload determination value and the return determination value is set to a maximum value in response to the rotation speed being equal to or higher than the maximum use rotation speed. What is set to the value at the used rotation speed is adopted.

A fan motor control device according to a thirty-first aspect of the present invention employs, as the determination value setting means, one that sets an overload determination value to a current value at a higher load as the rotational speed decreases.

A fan motor control device according to a thirty-second aspect employs, as the determination value setting means, one that sets an overload determination value to a current value at a higher load as the rotation speed increases.

A fan motor control device according to a thirty-third aspect employs, as the determination value setting means, one that sets an overload determination value in accordance with an operating region.

According to a thirty-fourth aspect of the present invention, as the overload detecting means, the overload determination value at the maximum operating speed is set to a value larger than the current value corresponding to the maximum load at which the fan motor should be started. It is what adopts what is done.

The fan motor control device according to claim 35 employs, as the overload detecting means, one that employs a peak hold value, an average value, or an effective value of a current as a DC current value or a fan motor current value. is there.

A fan motor control device according to a thirty-sixth aspect employs, as the command rotation speed control means, one that sets the degree of change in the set value of the command rotation speed to be longer than the settling time of the speed control.

In the fan motor control device according to the present invention, as the command speed control means, the degree of decrease in the set value of the command speed is set to be lower than the temperature rise at which the fan control means is destroyed. Is adopted.

The fan motor control device according to claim 38 employs, as the overload detecting means, one in which a judgment value is set for each value coarser than the rotational speed resolution and a value at the intermediate rotational speed is determined by interpolation processing. Is what you do.

According to a thirty-ninth aspect of the present invention, in the fan motor control means, the fan control means stops the waveform output in response to the command rotation speed and the actual rotation speed being equal to or less than the waveform output stop rotation speed during the rotation speed reduction operation. It is what adopts what is done.

The fan motor control device according to claim 40 employs, as the fan control means, one that sets the waveform output stop rotation number according to whether the apparatus is in the normal operation or during the startup.

The fan motor control device according to claim 41, wherein the fan control means sets the waveform output stop rotation speed corresponding to the starting operation to a value lower than the waveform output stop rotation speed corresponding to the normal operation. To adopt.

A fan motor control device according to claim 42 employs, as the fan control means, one that turns off all switching elements included in the fan control means when the waveform output is stopped.

A fan motor control apparatus according to claim 43 employs a fan motor for driving a fan included in an air conditioner.

A fan motor controller according to claim 44 employs a brushless DC motor as the fan motor.

[0063]

According to the fan motor control method of the present invention, when driving the fan motor by the fan control means, the load on the fan motor is detected, and in response to the detected load being equal to or more than the predetermined load. Since the command speed to be supplied to the fan control means is reduced and the command speed to be supplied to the fan control means is increased in response to the detected load being smaller than the predetermined load, The protection of the fan motor and the fan control means can be achieved, and a sufficient air volume can be secured.

According to the fan motor control method of the present invention, when driving the fan motor by the fan control means, the load on the fan motor is detected, and after the detected load exceeds a predetermined load, Until it becomes smaller, the command speed continues to decrease, and after the detected load becomes smaller than the predetermined load, the command speed continues to increase, so the current value increases more positively. And lowering, which in turn
The protection of the fan motor and the fan control means can be achieved, and a sufficient air volume can be secured.

According to the fan motor control method of claim 3, since the load detection is performed using the DC current value of the fan control means or the fan motor current value and the rotation speed of the fan motor, the load value is detected using the current value. Claim 1 or Claim 2
The same operation as described above can be achieved.

According to the fan motor control method of the present invention, the overload state is detected in response to the detected load being equal to or higher than the predetermined load. In addition to the operation described above, the overload state can be reliably detected.

According to the fan motor control method of the present invention, the overload state is detected in response to the current value being equal to or greater than the overload determination value indicating the overload state, and the current value is reduced to the overload elimination state. 2. The overload elimination state is detected in response to the return determination value indicating a value equal to or less than the return determination value indicating the value.
Accordingly, in addition to the function of any one of the fourth and fourth aspects, it is possible to appropriately reduce the rotation speed and increase the rotation speed, and to reduce the current.

According to the fan motor control method of claim 6, at least one of the overload judgment value and the return judgment value is set in accordance with the number of revolutions. Thus, overheating of the fan control means can be positively prevented.

According to the fan motor control method of the present invention, at least one of the overload judgment value and the return judgment value is set to be larger at a higher rotation speed and smaller at a lower rotation speed. In addition, more effective protection of the fan control means can be achieved.

According to the fan motor control method of the present invention, at least one of the overload judgment value and the return judgment value is set to a value at the maximum use rotation speed in response to the rotation speed being higher than the maximum use rotation speed. Therefore, in addition to the operation of claim 6 or claim 7, it is possible to reduce the number of revolutions higher than the maximum use number of revolutions to near the maximum use number of revolutions, thereby limiting the fan motor current and controlling the fan control means. Can be prevented from being thermally destroyed.

In the fan motor control method according to the ninth aspect, the overload determination value is set to a current value at a high load as the rotational speed decreases. In addition, the number of rotations can be settled according to the load.

In the fan motor control method according to the tenth aspect, the overload determination value is set to a current value at a higher load as the rotation speed increases. In addition, once it is determined that an overload has occurred, the vehicle can be quickly decelerated.

According to the fan motor control method of the eleventh aspect, since the overload judgment value is set according to the operating range, in addition to the operation of any of the sixth to eighth aspects, the control of the load is controlled. The degree of freedom can be increased.

According to the fan motor control method of the twelfth aspect, the overload judgment value at the maximum operating speed is set to a value larger than the current value corresponding to the maximum load at which the fan motor should be started. In addition to the function of any one of the first to eleventh aspects, it is possible to surely rotate at the maximum rotational speed in a steady state.

According to the fan motor control method of claim 13, the peak hold value, average value or effective value of the current is adopted as the DC current value or the fan motor current value. In addition to the effect of any one of the above, stabilization of the detection value and reduction of the microcomputer processing can be achieved.

According to the fan motor control method of the fourteenth aspect, the degree of change in the set value of the command rotation speed is set to be longer than the settling time of the speed control. In addition, operation stability can be ensured.

According to the fan motor control method of the fifteenth aspect, the degree of decrease in the set value of the command rotation speed is set to be lower than the temperature increase at which the fan control means is destroyed. In addition to the effect of any one of the thirteenth to thirteenth aspects, reliable protection of the fan control means can be achieved.

According to the fan motor control method of the present invention, the determination value is set for each value coarser than the rotational speed resolution, and the value at the intermediate rotational speed is determined by interpolation processing. In addition to the function of any one of claims 15,
The control software can be simplified and the memory capacity of the microcomputer can be reduced.

According to the fan motor control method of the present invention, the waveform output from the fan control means is provided in response to the command rotation speed and the actual rotation speed being equal to or less than the waveform output stop rotation speed during the rotation speed reduction operation. Since the operation is stopped, in addition to the function of any one of the first to sixteenth aspects, it is possible to achieve overheat protection and prevention of malfunction due to fluctuations in the rotation speed.

According to the fan motor control method of the eighteenth aspect, the waveform output stop rotation speed is set according to the start and the normal operation. Operational stability during normal operation can be ensured.

According to the fan motor control method of the nineteenth aspect, the waveform output stop rotation speed corresponding to the start is set to a value lower than the waveform output stop rotation speed corresponding to the normal operation. In addition to the effects of the eighteenth aspect, it is possible to achieve particularly prevention of malfunction at startup.

According to the twentieth aspect, when the waveform output is stopped, all the switching elements included in the fan control means are turned off.
In addition to the function of any one of the seventh to nineteenth aspects, it is possible to achieve a DC overvoltage prevention and a malfunction prevention under a high load when a strong wind is applied.

According to the fan motor control method of the present invention, since a fan motor for driving a fan included in an air conditioner is adopted as the fan motor, the present invention is applied to an air conditioner and is applied to the air conditioner. The same operation as any of the above 20 can be achieved.

According to the fan motor control method of claim 22, since a brushless DC motor is employed as the fan motor, energy saving can be achieved in addition to any of the functions of claims 1 to 21. .

According to the fan motor control device of claim 23, when driving the fan motor by the fan control means, the load is detected by the load detection means on the fan motor, and the load detected by the command rotation speed control means is detected. Is smaller than the predetermined load, the command speed to be supplied to the fan control means is reduced, and the command to be supplied to the fan control means is reduced in response to the detected load being smaller than the predetermined load. The rotation speed can be increased.

Therefore, protection of the fan motor and the fan control means can be surely achieved, and a sufficient air volume can be secured.

According to the fan motor control device of the present invention, when driving the fan motor by the fan control means, the load is detected by the load detection means on the fan motor, and the load detected by the command rotation speed control means is detected. After the load becomes equal to or more than the predetermined load, the command rotation speed is continuously reduced until the load becomes smaller than the predetermined load, and after the detected load becomes smaller than the predetermined load, the command rotation speed is continuously increased. Can be.

Therefore, it is possible to more positively increase and decrease the current value, thereby achieving protection of the fan motor and the fan control means and securing a sufficient air flow.

According to a twenty-fifth aspect of the present invention, the load detecting means employs a means for detecting a load using a DC current value of the fan controlling means or a fan motor current value and the number of revolutions of the fan motor. Therefore, the same operation as in claim 23 or claim 24 can be achieved using the current value.

According to the fan motor control device of the twenty-sixth aspect, since the load detection means detects an overload state in response to the detected load being equal to or more than a predetermined load, In addition to the function of any of claims 23 to 25, an overload state can be reliably detected.

In the fan motor control device according to claim 27, the overload detecting means detects an overload state in response to a current value being equal to or greater than an overload determination value indicating an overload state, A system for detecting the overload elimination state in response to the current value being equal to or less than the return determination value indicating the overload elimination state is employed. In addition, the rotation speed can be reduced and the rotation speed can be appropriately increased, and the current can be reduced.

According to the fan motor control device of the twenty-eighth aspect, as the overload detecting means, a means including a judgment value setting means for setting at least one of an overload judgment value and a return judgment value in accordance with the number of revolutions is adopted. Claim 2
In addition to the operation of 7, the overheating of the fan control means can be positively prevented in consideration of the air volume.

In the fan motor control device according to the present invention, as the determination value setting means, at least one of the overload determination value and the return determination value is set to be larger at a higher rotation speed and smaller at a lower rotation speed. Since this is adopted, more effective protection of the fan control means can be achieved in addition to the effect of claim 28.

According to the fan motor control device of the present invention, as the determination value setting means, at least one of the overload determination value and the return determination value is responded to the fact that the rotation speed is equal to or higher than the maximum use rotation speed. Since the value set to the value at the maximum operating speed is adopted, in addition to the effect of claim 28 or 29, it is possible to reduce the rotational speed higher than the maximum operating speed to near the maximum operating speed. Thus, the limitation of the fan motor current and the prevention of thermal destruction of the fan control means can be achieved.

According to the fan motor control device of claim 31, since the overload determination value is set to a current value at a high load as the number of revolutions decreases, the determination value setting means is adopted. In addition to the effect of any one of Claims 28 to 30, the number of rotations can be reduced to a value corresponding to the load.

In the fan motor control device according to claim 32, as the determination value setting means, an overload determination value is set to a current value at a higher load as the rotation speed increases. In addition to the effect of any one of Claims 28 to 30, in the case where the overload is once determined, the vehicle can be quickly decelerated.

According to the fan motor control apparatus of claim 33, since the means for setting the overload judgment value in accordance with the operating range is adopted as the judgment value setting means, the fan motor control apparatus of claim 28 to claim 30 In addition to any of the functions, the degree of freedom in controlling the load can be increased.

In the fan motor control device according to the thirty-fourth aspect, as the overload detecting means, the overload judgment value at the maximum operating speed is set to a value larger than the current value corresponding to the maximum load at which the fan motor should be started. Therefore, in addition to the operation according to any one of the twenty-third to thirty-third aspects, it is possible to surely rotate at the maximum rotational speed in a steady state.

In the fan motor control device according to claim 35, since the overload detecting means adopts a DC current value or a peak hold value or an average value of the fan motor current as the current value, In addition to the function of any of claims 23 to 34, stabilization of the detected value and reduction of the microcomputer processing can be achieved.

According to the fan motor control device of the present invention, since the command rotation speed control means sets the degree of change in the set value of the command rotation speed greater than the settling time of the speed control, In addition to the function of any of claims 23 to 35, stability of operation can be ensured.

In the fan motor control device according to claim 37, as the command rotation speed control means, the degree of decrease in the set value of the command rotation speed is set so as to be lower than the temperature rise at which the fan control means is destroyed. Therefore, in addition to the function of any one of claims 23 to 35, reliable protection of the fan control means can be achieved.

In the fan motor control device according to the thirty-eighth aspect, as the overload detecting means, the judgment value is set for each value coarser than the rotational speed resolution, and the value at the intermediate rotational speed is determined by interpolation processing. Therefore, in addition to the effects of any one of claims 23 to 37, simplification of control software and reduction of the memory capacity of the microcomputer can be achieved.

According to the fan motor control device of the present invention, the fan control means includes:
Since the output of the waveform is stopped in response to the command rotation speed and the actual rotation speed being equal to or lower than the waveform output stop rotation speed, in addition to the function of any one of claims 23 to 38, overheating is performed. Protection and malfunction prevention due to fluctuations in the number of revolutions can be achieved.

According to the fan motor control apparatus of claim 40, the fan control means for setting the waveform output stop rotation number according to whether the apparatus is operating during normal operation or during start-up is adopted. In addition to the operation, operational stability during acceleration after startup and during normal operation can be ensured.

According to the fan motor control device of the present invention, as the fan control means, the waveform output stop rotation speed corresponding to the start is set to a value lower than the waveform output stop rotation speed corresponding to the normal operation. Since this is adopted, in addition to the effect of claim 40, it is possible to achieve particularly prevention of malfunction at the time of startup.

According to the fan motor control device of the present invention, since the fan control means which turns off all the switching elements included in the fan control means at the time of stopping the waveform output is adopted. Accordingly, in addition to the function of any one of claims 41 to 41, DC overvoltage prevention and malfunction prevention during strong wind application can be achieved.

According to the fan motor control device of the present invention, since a fan motor for driving a fan included in an air conditioner is employed as the fan motor, the present invention is applied to an air conditioner. The same operation as any one of the items 42 can be achieved.

According to the fan motor control device of claim 44, since a brushless DC motor is employed as the fan motor, energy saving can be achieved in addition to the operation of any of claims 23 to 43. .

[0109]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a fan motor control method according to an embodiment of the present invention;

FIG. 1 is a block diagram showing one embodiment of the fan motor control device of the present invention.

This fan motor control device has an AC power source 1
To the rectifier circuit 1a to generate a DC voltage, apply this DC voltage to the inverter main circuit 2a, and supply the output waveform from the inverter main circuit 2a to the stator winding 3a of the brushless DC motor 3. . The fan 3c is rotated by the rotor 3b of the brushless DC motor 3.

The position signal H output from the three Hall sensors 4 incorporated in the brushless DC motor 3
u, Hv, and Hw as inputs, a rotation speed calculation unit 5 that calculates the current rotation speed based on the cycle of the position signal, a current detection circuit 6 that detects a current in the DC unit of the inverter main circuit 2a, An overload detection / rotational speed reduction control unit 7 that performs an overload detection and a rotational speed reduction operation to calculate a rotational speed command vs * by using the number, a rotational speed command v * supplied from the outside, and a detected current as inputs; A rotation speed control unit 8 that calculates a duty command D * by performing a rotation speed control operation with the current rotation speed and a rotation speed command vs * as inputs, and a gate signal with the position signals Hu, Hv, Hw and the duty command D * as inputs. Gu, Gv, Gw, Gx, Gy, Gz
, An overcurrent protection circuit 10 that performs overcurrent protection using the detected current as an input, and outputs an overcurrent protection signal, and gate signals Gu, Gv, Gw, Gx, and G.
a gate drive circuit 2b for inputting y and Gz as inputs and outputting a gate drive signal for controlling on / off of each switching element of the inverter main circuit 2a, and stopping the output of the gate drive signal with an overcurrent protection signal as input; have.

The operation of the fan motor control device having the above configuration is as follows.

The direct current is detected by the current detecting circuit 6. For example, when the microcomputer controls the motor,
Input from the input port.

The overload detection / rotational speed reduction control unit 7 determines whether or not an overload is present on the basis of the detected current value and the current rotational speed. The number command v * is reduced to create a new rotation speed command vs *.

In the rotation speed control unit 8, the rotation speed command v
Rotation speed control is performed based on s * and the current rotation speed. The operation of the other control units is the same as in the case where the rotation speed reduction control is not performed.

In the above embodiment, the DC current value of the inverter main circuit 2a is detected. However, it is possible to detect the motor current to detect the overload.

Further description will be given.

When a fan motor is driven in an air conditioner or the like, the amount of heat generated in the inverter main circuit 2a is determined by the value of the loss in the inverter main circuit 2a, and therefore largely depends on the current value. On the other hand, the cooling effect of the wind generated by the fan 3c depends on the rotation speed. Therefore,
When performing appropriate inverter overheat protection, it is preferable to detect the rotation speed and the current value to perform protection.

FIG. 2 shows the relationship between the DC current value, motor current value, and inverter temperature rise value (driver temperature rise value) when the load applied from the outside in the outdoor fan motor of the air conditioner is constant. FIG.

As can be seen from FIG. 2, the current value decreases as the rotation speed decreases, and the temperature rise value decreases due to the decrease in the amount of heat generated. Therefore, in order to protect the inverter from overheating, it is effective to detect the DC current or the motor current and, if an overload is detected, to reduce the current value by lowering the rotation speed command to lower the actual rotation speed. It is.

What is important here is to suppress the rise in the temperature of the inverter while continuing to rotate without immediately stopping the fan motor when an overload is detected. In this case, the amount of air passing through the heat exchanger can be secured, and refrigerant control can be performed stably.

That is, by employing the above-described embodiment, it is possible to achieve both the overheat protection of the inverter and the securing of the air volume.

FIG. 3 is a flowchart illustrating one embodiment of the fan motor control method according to the present invention.

In step SP1, it is determined whether or not the detected current value is equal to or greater than the overload determination current value. If it is determined that the detected current value is equal to or greater than the overload determination current value,
In step SP2, for example, vs * (n) = vs
* (N-1) -vdown is calculated to reduce the rotational speed command. Here, vs * (n) is the rotation speed command value obtained this time, vs * (n-1) is the rotation speed command value obtained last time,
vdown is a rotation speed command reduction value per control cycle.

If it is determined in step SP1 that the detected current value is not more than the overload determination current value, in step SP3, the rotational speed command is decreasing (vs * <v *).
It is determined whether or not the rotation speed command is not being reduced, and in step SP4, a process {vs * (n) = v *} of not changing the rotation speed command is performed.

If it is determined in step SP3 that the rotational speed command is decreasing, it is determined in step SP5 whether or not the detected current value is equal to or smaller than the return determination current value. If it is determined that the value is equal to or less than the value, in step SP6, for example, vs.
An operation of * (n) = vs * (n-1) + vup is performed to increase the rotational speed command. Conversely, if it is determined in step SP5 that the detected current value is not smaller than or equal to the return determination current value, in step SP7, the process of retaining the rotational speed command {vs * (n) = vs * (n-1)}. I do. Here, vup is a rotation speed command increase value per control cycle.

When the processing of step SP2, the processing of step SP4, the processing of step SP6, or the processing of step SP7 is performed, the obtained rotation speed command vs * (n) is sent to the rotation speed control unit. Supply.

Therefore, as shown in FIG.
If the detected current is equal to or larger than the overload determination current value, the operation for reducing the number of rotations starts immediately, and the operation stops at the number of rotations that is less than the overload determination current value. Then, the return operation is performed only when the load decreases and becomes equal to or less than the return determination current value.

Also, since there is a rotation speed reduction operation stop area,
If the load is equilibrated with the current value in the stop range once the operation has started to decrease, the rotation speed may not change at a rotation speed lower than the command rotation speed. In this case, if the load is constant even when the rotational speed decreases, the rotational speed fluctuation is small.

FIG. 4 is a flowchart illustrating another embodiment of the fan motor control method according to the present invention.

In step SP1, it is determined whether or not the detected current value is equal to or greater than the overload determination current value. If it is determined that the detected current value is not equal to or greater than the overload determination current value,
In step SP2, the rotational speed command is decreasing (vs * <
v *), and when it is determined that the rotation speed command is not decreasing, a process {vs * (n) = v *} of not changing the rotation speed command is performed in step SP3, and step SP4 is performed. , The lowering flag is set to 0.

If it is determined in step SP2 that the rotational speed command is decreasing, it is determined in step SP5 whether or not the detected current value is equal to or smaller than the return determination current value. If it is determined that it is not less than the value, it is determined in step SP6 whether or not the lowering operation flag is 1.

If it is determined in step SP5 that the detected current value is equal to or smaller than the return determination current value, or if it is determined in step SP6 that the in-operation flag is not 1, for example, in step SP7, The operation of vs * (n) = vs * (n-1) + vup is performed to increase the rotational speed command, and in step SP8, the flag during the lowering operation is set to 0.

If it is determined in step SP1 that the detected current value is equal to or greater than the overload determination current value, or if it is determined in step SP6 that the in-operation flag is 1, then in step SP9, for example, v
The rotation speed command is reduced by performing the calculation of s * (n) = vs * (n-1) -vdown, and the reduction flag is set to 1 in step SP10.

Therefore, as shown in FIG.
When the detected current becomes equal to or more than the overload determination current value and the operation starts to reduce the rotation speed, the rotation speed continues to decrease until the detected current becomes equal to or less than the return determination current value. Further, when the rotation speed returning operation is started due to the current decrease due to the rotation speed lowering operation or the current decrease due to the decrease in the load, the rotation speed continues to increase until it becomes equal to or more than the overload determination current value.

Therefore, even if the load is constant, the rotational speed fluctuation becomes large, but the response to the load fluctuation is good. It does not settle down at a rotation speed lower than the command rotation speed.

The embodiment shown in FIG. 3 or 4 will be further described.

In an application such as a fan motor for an air conditioner, which cools an inverter (or a radiating fin) by wind generated by itself, even if the current value is the same, that is, the heat generation amount is the same, the cooling capacity ( (Air volume) changes depending on the number of rotations of the fan, so that the inverter temperature also changes. Therefore, for inverter overheat protection,
It is desirable to set an overload determination current value according to the rotation speed. With this setting, the inverter can be protected at the same time while maintaining the heat exchanger passing airflow that varies according to the strength of the backwind load as much as possible.

At this time, since the cooling capacity is smaller as the rotation speed becomes lower, the inverter temperature becomes higher if the heat generation amount is the same. In other words, by reducing the amount of heat (that is, the current value) as the rotational speed decreases, more effective inverter overheat protection can be performed. In other words, more effective inverter protection can be performed by setting the overload determination current value set in accordance with the rotation speed to be higher at higher rotation speeds and smaller at lower rotation speeds.

The return determination current value also changes according to the number of revolutions when it is desired to perform the return operation promptly. In other words, the value may be set to a value corresponding to the overload determination current value. However, in the case where an operation of returning when the current value itself becomes equal to or less than the predetermined value is performed, a constant value may be set regardless of the rotation speed. .

Further, the region of the fan motor whose rotation speed is equal to or higher than the maximum number of rotations is the rotation speed which is not originally required, and the current value becomes larger. Since it is not desirable to rotate the fan motor in such a region, by setting the overload determination current value to a value at the maximum operating speed, in an area above the maximum operating speed, an externally applied load is reduced. Even when the rotation speed is small, it is possible to reduce the rotation speed to near the maximum use rotation speed by performing the rotation speed reduction operation. In particular, it is important to set such a set value from the viewpoint of motor current limitation and prevention of inverter thermal destruction.

In consideration of such points, as shown in FIG. 6, it is preferable to change the overload judging current value and the return judging current value according to the rotation speed.

In the case of performing protection by detecting overload, the protection of the inverter or fan motor is not significant if the inverter or the fan motor is thermally damaged before the protection is performed. It is necessary to set a current value that does not cause thermal damage to the fan motor.

Further, if the overload determination current value is smaller than the current value when there is no wind, it becomes impossible to drive the motor at the rotation speed when there is no wind, and such a set value is meaningless. Similarly, if the return determination current value is set to a value that does not enter the return operation when there is no wind, the operation required as a fan motor cannot be performed, and it is meaningless at all.

In general, there are variations in the DC current value and the motor current value, and a detection error occurs in the current detection. If the difference between the overload judgment current value and the return judgment current value is set to a value smaller than this variation or error, the originally expected operation cannot be performed, and appropriate inverter overheat protection must be performed. Can not be done. Therefore, both current values are set so that the difference between the overload determination current value and the return determination current value is larger than the variation or error.

Next, the setting of the overload determination current value will be specifically described.

(A) and (b) of FIG. 7 are diagrams showing examples of the DC current detection value and the overload judgment current setting value at the time of no wind and at the time of reverse wind.

As shown in FIG. 2, the current value increases as the rotation speed increases. In addition, when a reverse wind having a constant wind speed is applied, a change rate with respect to the number of revolutions changes, but a larger current flows than when there is no wind.

FIG. 7A shows a state in which the overload determination current value is set to a value corresponding to a higher load as the rotational speed decreases.

In this case, in order to withstand a higher load at a low rotational speed, when a reverse wind is applied to the overload determination current value, the rotational speed is set to a value corresponding to the reverse wind. And
If the strength of the headwind fluctuates, the calming speed also fluctuates. However, it has the advantage of good responsiveness to load fluctuations.

FIG. 7 (a) shows a state in which the overload determination current value is set to a value corresponding to a higher load as the engine speed increases.

In this case, in order to endure a higher load at a high rotation speed, the rotation speed is reduced steadily if a reverse wind that affects the overload determination current value continues to blow. Therefore, when a load equal to or more than a predetermined value is applied, the present invention is suitable for a case where the rotation speed is rapidly reduced to stop.

(B) in FIG. 7 is a combination of (a) in FIG.

FIG. 7 (b) shows a state in which at a certain rotational speed n1 or more, a lower rotational speed corresponds to a set value corresponding to a higher load, and when it is less than n1, a higher rotational speed corresponds to a set value corresponding to a higher load. ing.

In this case, when the speed is n1 or more, the load can be more endured at a low rotation speed, and when it is less than n1, the load can be endured at a high rotation speed.
In other words, when the rotation speed is higher than a certain rotation speed, the cooling effect is large due to the high wind speed. Therefore, the response value is set as an important value. What should I do?

FIG. 7B shows a set value corresponding to a higher load at a higher rotational speed than a certain rotational speed n2.
A value less than the value indicates a state in which a set value corresponding to a higher load is obtained at a low rotation speed.

In this case, when the speed is n2 or more, the load can be more endured at a high rotation speed, and when it is less than n2, the load can be endured at a low rotation speed.
In other words, if it is absolutely necessary to secure a certain air volume, or if the temperature rises to a minimum at a certain rotation speed, and if it is desired to decelerate to that rotation speed above a predetermined load, this setting is used. It should be a value.

In FIG. 7 (b), the number of rotations whose setting is changed is only one of n1 and n2. However, the inclination of the set value of the overload determination current is changed depending on the number of rotations. May be set so as to calm down at several points.

FIG. 8 is a block diagram showing another embodiment of the fan motor control device of the present invention.

This fan motor control device differs from the fan motor control device of FIG. 1 only in that a peak hold circuit 11 is provided between the current detection circuit 6 and the overload detection / rotation speed reduction control unit 7. is there.

When this fan motor control device is adopted, the instantaneous value of the DC current fluctuates, but the influence of such fluctuation can be eliminated by using the peak hold value (see FIG. 9). Stable control can be realized.

As can be seen from FIG. 9, the peak hold value and the average value are different from each other, but have similar changes. Therefore, an average value circuit should be used instead of the peak hold circuit. Can also. When a motor current is used as a current value for detecting an overload, similar control can be realized by using a peak hold value or an effective value.

It is preferable that the overload determination current value and the return determination current value are set for each rotation speed. However, if the set values are provided for each rotation speed resolution, a table on the microcomputer software becomes large. Squeeze memory capacity. FIG. 10 is a diagram for explaining a method for solving such a problem. The overload determination current value is set for each rotation speed coarser than the rotation speed resolution, and the overload determination current value at the rotation speed in between is the set value. Can be determined by an interpolation operation based on

More specifically, since the driving speed of the fan motor for an air conditioner is about 1200 m at the maximum, if the number of elements in the appropriate table is considered to be about 5 to 20, the setting of the overload judgment current value is performed. Interval is more than 50rpm and 200rpm
It may be set to the following level.

For example, an overload determination current value is set from 0 rpm to 1100 rpm every 100 rpm, and the value is set to I
If judge (0) to Ijudge (11), the overload determination current value at the current rotational speed Nrpm is dr ×
It can be calculated by performing the calculation of di / 100 + Ijudge (i). Here, i is an integer part of N / 100, and di = Ijudge (i + 1) -Ijudge.
(I), dr = N-100 × i.

FIG. 11 is a flowchart for explaining still another embodiment of the fan motor control method according to the present invention.

In step SP1, it is determined whether or not the motor has been started (whether it has once passed the waveform output stop rotation speed 1). If it is determined that the motor has been started, in step SP2, the waveform output stop rotation speed is determined. Is set to the waveform output stop rotation speed 1, and conversely, if it is determined in step SP1 that it is not the start time, the waveform output stop rotation speed is set to the waveform output stop rotation speed 2 in step SP3.

When the processing in step SP2 or the processing in step SP3 is performed, the processing in step SP
In 4, it is determined whether the command rotation speed is less than the waveform output stop rotation speed and the current rotation speed is less than the waveform output stop rotation speed, and at least one of the command rotation speed and the current rotation speed stops the waveform output stop. If it is determined that the rotation speed is not less than the rotation speed, the waveform output (rotation speed lowering operation) is continued in step SP5. Conversely, when it is determined in step SP4 that both the command rotation speed and the current rotation speed are less than the waveform output stop rotation speed, the waveform output is stopped in step SP6.

Therefore, during normal operation, as shown in FIG. 12A, the waveform output stop rotation speed 1 is adopted as the waveform output stop rotation speed when the rotation speed lowering operation is performed.
When both the current rotation speed and the command rotation speed are less than the waveform output stop rotation speed 1, the waveform output is stopped.

At the time of startup, the waveform output stop rotation speed 1 is used as the waveform output stop rotation speed when the rotation speed lowering operation is performed.
A lower waveform output stop rotation speed of 2 is adopted, and when both the current rotation speed and the command rotation speed are less than the waveform output stop rotation speed, the waveform output is stopped.

Further description will be given.

If the rotational speed is sufficiently reduced during the rotational speed lowering operation, the external load (backwind) is considered to be in a considerably strong state. Therefore, the fan motor is not intentionally driven, and the external load is left to the external load. It is preferable that the rotation be performed so as to obtain a larger air flow rate passing through the heat exchanger, and also from the viewpoint of protecting the inverter, the waveform output be stopped. That is, a waveform output stop rotation speed for performing the rotation speed lowering operation is provided, and the waveform output is stopped when both the command rotation speed and the actual rotation speed become lower values. If this determination is performed only with the actual rotation speed, for example, the waveform output is stopped even when the rotation speed is reduced even though the load is not increased due to a power supply voltage fluctuation or the like, and the original fan motor operation is performed. May not be possible.

In order to reliably perform the waveform output stop operation even near the minimum rotation speed during operation, set a certain margin for the waveform output stop rotation speed with respect to the minimum command rotation speed (minimum use rotation speed). Must be set. Also, if the same waveform output stop rotation speed is used during startup, the stability against overload will be reduced until the actual rotation speed has accelerated to the waveform output stop rotation speed. It is preferable to set the output stop rotation speed.

The processing of the flowchart of FIG. 11 takes these points into consideration, and a good waveform output stop can be performed at any of the start-up and the normal operation.

As one method of stopping the waveform output,
There is a method of turning off only the drive signal of the switching element of one arm that does not perform chopping of the inverter main circuit. An induced voltage is generated in the motor, and the inverter performs a role of a chopper to increase the DC voltage. Another method is to turn off the drive signals of all the switching elements of the inverter main circuit. This method is preferable to the former method because it does not involve the operation of boosting the DC voltage.

In each of the above embodiments, not only a brushless DC motor but also an AC motor such as an induction motor can be used as the fan motor. However, the motor efficiency between the induction motor and the brushless DC motor is shown in FIG.
Therefore, it is preferable to use a brushless DC motor as the fan motor.

[0178]

According to the first aspect of the present invention, the protection of the fan motor and the fan control means can be surely achieved, and a sufficient effect that a sufficient air volume can be secured can be obtained.

According to the second aspect of the present invention, it is possible to more positively increase and decrease the current value, thereby achieving the protection of the fan motor and the fan control means, and ensuring a sufficient air volume. It has the unique effect of being able to.

According to the third aspect of the invention, the same effects as those of the first or second aspect can be obtained by using the current value.

The invention according to claim 4 is the invention according to claims 1 to 3.
In addition to the effect of any one of the above, there is an effect that the overload state can be reliably detected.

The invention according to claim 5 is the invention according to claims 1 to 4.
In addition to the effect of any one of the above, a specific effect that the rotation speed can be reduced and the rotation speed increased appropriately and the current can be reduced can be achieved.

The invention of claim 6 has a unique effect that the overheating of the fan control means can be positively prevented in consideration of the air volume in addition to the effect of claim 5.

The invention of claim 7 has a unique effect that more effective protection of the fan control means can be achieved in addition to the effect of claim 6.

According to the eighth aspect of the present invention, in addition to the effects of the sixth and seventh aspects, it is possible to reduce the number of revolutions higher than the maximum use speed to near the maximum use speed, thereby limiting the fan motor current. This has the specific effect of preventing the thermal destruction of the fan control means.

The ninth aspect of the present invention relates to the sixth to eighth aspects.
In addition to the effect of any one of the above, a unique effect that the number of rotations can be settled according to the load can be obtained.

[0187] The invention of claim 10 has the specific effect of being able to quickly decelerate once the overload is determined, in addition to the effect of any of claims 6 to 8.

According to the eleventh aspect of the present invention, in addition to the effect of any one of the sixth to eighth aspects, there is a specific effect that the degree of freedom in controlling the load can be increased.

According to the twelfth aspect of the invention, in addition to the effect of any one of the first to eleventh aspects, a unique effect is obtained that the motor can be surely rotated at the maximum number of revolutions in a steady state.

According to the thirteenth aspect, in addition to the effects of any one of the first to twelfth aspects, there is a specific effect that the detection value can be stabilized and the microcomputer processing can be reduced.

The invention of claim 14 has a unique effect that operation stability can be ensured in addition to the effect of any of claims 1 to 13.

According to the fifteenth aspect of the present invention, in addition to the effects of any one of the first to thirteenth aspects, a special effect that the protection of the fan control means can be surely achieved can be achieved.

[0193] The invention of claim 16 has the specific effect that control software can be simplified and the memory capacity of the microcomputer can be reduced, in addition to the effects of any one of claims 1 to 15. .

In addition to the effect of any one of claims 1 to 16, the present invention has the unique effect that overheat protection and malfunction prevention due to rotation speed fluctuation can be achieved.

According to the eighteenth aspect of the invention, in addition to the effect of the seventeenth aspect, there is a special effect that operation stability during acceleration after startup and during normal operation can be ensured.

The nineteenth aspect of the present invention has a special effect that, in addition to the effect of the eighteenth aspect, malfunction can be prevented particularly during acceleration after startup.

According to the twentieth aspect of the present invention, in addition to the effects of the seventeenth to nineteenth aspects, a special effect that DC overvoltage prevention and malfunction prevention during strong wind application can be achieved.

The twenty-first aspect of the invention has the same effects as any of the first to twentieth aspects by being applied to an air conditioner.

According to the invention of claim 22, in addition to the effect of any one of claims 1 to 21, there is a special effect that energy saving can be achieved.

According to the twenty-third aspect of the present invention, it is possible to surely achieve the protection of the fan motor and the fan control means, and to achieve a specific effect that a sufficient air volume can be secured.

According to the twenty-fourth aspect of the present invention, it is possible to more positively increase and decrease the current value, thereby achieving protection of the fan motor and the fan control means, and ensuring a sufficient air volume. It has the unique effect of being able to.

According to the twenty-fifth aspect, the same effect as the twenty-third aspect or the twenty-fourth aspect can be obtained by using a current value.

According to the twenty-sixth aspect of the present invention, in addition to the effects of the twenty-third to twenty-fifth aspects, a special effect that an overload state can be reliably detected.

According to the twenty-seventh aspect, in addition to the effects of any one of the twenty-third to twenty-sixth aspects, it is possible to appropriately reduce the rotation speed and increase the rotation speed, and to reduce the current. Has a unique effect.

According to the twenty-eighth aspect of the present invention, in addition to the effect of the twenty-seventh aspect, a special effect that overheating of the fan control means can be positively prevented in consideration of the air volume.

According to the twenty-ninth aspect of the present invention, in addition to the effect of the twenty-eighth aspect, there is a specific effect that more effective protection of the fan control means can be achieved.

According to a thirtieth aspect of the present invention, in addition to the functions of the twenty-eighth and twenty-ninth aspects, the number of revolutions equal to or higher than the maximum number of revolutions can be reduced to near the maximum number of revolutions. This has the specific effect of preventing the thermal destruction of the fan control means.

The invention of claim 31 has a unique effect that the number of rotations can be reduced to a value corresponding to the load, in addition to the effect of any of claims 28 to 30.

[0209] The invention of claim 32 has the specific effect of being able to quickly decelerate once it is determined that an overload has occurred, in addition to the effect of any of claims 28 to 30.

The invention of claim 33 has a specific effect that the degree of freedom in controlling the load can be increased in addition to the effect of any of claims 28 to 30.

[0211] The invention of claim 34 has a unique effect that it is possible to surely rotate at the maximum rotational speed in a steady state, in addition to the effect of any of claims 23 to 33.

The invention of claim 35 has a specific effect that, in addition to the effect of any one of claims 23 to 34, stabilization of the detected value and reduction of the microcomputer processing can be achieved.

The invention of claim 36 has a unique effect that the stability of operation can be ensured in addition to the effect of any of claims 23 to 35.

The thirty-seventh aspect of the present invention has a unique effect that the protection of the fan control means can be surely achieved in addition to the effects of the twenty-third to thirty-fifth aspects.

The invention of claim 38 has the specific effect that the control software can be simplified and the memory capacity of the microcomputer can be reduced, in addition to the effect of any of claims 23 to 37. .

The invention of claim 39 has, in addition to the effects of any of claims 23 to 38, a special effect that overheat protection and malfunction prevention due to fluctuations in the number of revolutions can be achieved.

According to the invention of claim 40, in addition to the effect of claim 39, there is a special effect that operation stability during acceleration after startup and during normal operation can be ensured.

The invention of claim 41 has a unique effect that, in addition to the effect of claim 40, malfunction can be prevented particularly during acceleration after startup.

[0219] The invention of claim 42 has a specific effect that, in addition to the effect of any one of claims 39 to 41, it is possible to achieve prevention of DC overvoltage and prevention of malfunction when strong wind is applied.

When the invention of claim 43 is applied to an air conditioner, the same effect as any of claims 23 to 42 can be obtained.

The invention of claim 44 has a specific effect that energy saving can be achieved in addition to the effect of any of claims 23 to 43.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a fan motor control device of the present invention.

FIG. 2 is a diagram illustrating change characteristics of a DC current value, a motor current value, and a driver temperature rise value depending on the number of rotations.

FIG. 3 is a flowchart illustrating one embodiment of a fan motor control method according to the present invention.

FIG. 4 is a flowchart illustrating another embodiment of the fan motor control method of the present invention.

FIG. 5 is a diagram illustrating a rotation speed reduction operation and a rotation speed return operation.

FIG. 6 is a diagram illustrating change characteristics of the no-load current value, the overload determination current value, and the return determination current value depending on the rotation speed.

FIG. 7 is a diagram illustrating change characteristics of a current detection value and an overload determination current setting value depending on the number of rotations in the absence of wind and in the case of reverse wind.

FIG. 8 is a block diagram showing another embodiment of the fan motor control device of the present invention.

FIG. 9 is a diagram showing a temporal change of an instantaneous value, an average value, and a peak hold value of a direct current.

FIG. 10 is a diagram illustrating calculation of an overload determination current value set for each coarse rotation speed and an overload determination current value at the current rotation speed.

FIG. 11 is a flowchart illustrating still another embodiment of the fan motor control method of the present invention.

FIG. 12 is a diagram illustrating a waveform output stop rotation speed and an operation at the time of waveform output stop.

FIG. 13 is a diagram showing a change characteristic of the motor efficiency of the brushless DC motor and the induction motor depending on the rotation speed.

FIG. 14 is a block diagram showing a conventional fan motor control device.

FIG. 15 is a diagram illustrating creation of a 120-degree conduction drive signal.

FIG. 16 is a flowchart illustrating processing in a drive signal creation unit.

FIG. 17 is a diagram illustrating creation of a stop signal.

[Explanation of symbols]

2a Inverter main circuit 2b Gate drive circuit 3 Brushless DC motor 7 Overload detection / revolution speed reduction control unit 8 Revolution speed control unit 9 Drive signal generation unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Katsuhide Okamoto, Inventor, 1000 Oya, Okamoto-cho, Kusatsu-shi, Shiga 2nd Daikin Industries, Ltd. Shiga Works F-term (reference) 5H560 AA01 BB04 BB12 DA02 DA19 DC12 EB01 EC04 GG04 JJ02 JJ06 SS07 UA06 XA02 5H576 AA08 BB06 CC01 DD02 DD05 GG02 HA04 HB01 LL10 LL22 LL24 MM02 MM04 MM06 MM10

Claims (44)

[Claims] When a fan motor is driven by a fan control means, a load on the fan motor is detected, and a command rotation to be supplied to the fan control means in response to the detected load being equal to or greater than a predetermined load. A fan motor control method, comprising: decreasing the number of rotations and increasing a command rotation speed to be supplied to a fan control unit in response to a detected load being smaller than a predetermined load. In driving the fan motor by the fan control means, a load on the fan motor is detected, and after the detected load becomes equal to or more than a predetermined load, the command rotation is performed until the detected load becomes smaller than the predetermined load. A fan motor control method, wherein the command speed is continuously increased after the detected load becomes smaller than a predetermined load. 3. The fan motor control method according to claim 1, wherein the load detection is performed using a DC current value or a fan motor current value of the fan control means and a rotation speed of the fan motor. 4. The fan motor control method according to claim 1, wherein an overload state is detected in response to the detected load being equal to or greater than a predetermined load. 5. An overload state is detected in response to a current value being equal to or greater than an overload determination value indicating an overload state, and the current value is equal to or less than a return determination value indicating an overload cancellation state. The fan motor control method according to any one of claims 1 to 4, wherein the overload elimination state is detected in response to the following. 6. The fan motor control method according to claim 5, wherein at least one of the overload determination value and the return determination value is set according to the rotation speed. 7. The fan motor control method according to claim 6, wherein at least one of the overload determination value and the return determination value is set to be larger at a higher rotation speed and smaller at a lower rotation speed. 8. The system according to claim 6, wherein at least one of the overload judgment value and the return judgment value is set to a value at the maximum use rotation speed in response to the rotation speed being equal to or higher than the maximum use rotation speed. 3. The fan motor control method according to 1. 9. The fan motor control method according to claim 6, wherein the overload determination value is set to a current value at a higher load as the rotational speed decreases. 10. The fan motor control method according to claim 6, wherein the overload determination value is set to a current value at a higher load as the rotation speed increases. 11. The fan motor control method according to claim 6, wherein an overload determination value is set according to an operation region. 12. The overload determination value at the maximum operating speed is set to a value larger than a current value corresponding to a maximum load for starting the fan motor.
2. The fan motor control method according to claim 1, 13. The fan motor control method according to claim 1, wherein the DC current value or the fan motor current value is a peak hold value, an average value, or an effective value. 14. The fan motor control method according to claim 1, wherein the degree of change in the set value of the command rotation speed is set to be longer than the settling time of the speed control. 15. The fan motor control method according to claim 1, wherein the degree of decrease in the set value of the command rotation speed is set to be lower than the temperature increase at which the fan control means is destroyed. . 16. The fan motor control method according to claim 1, wherein the determination value is set for each value coarser than the rotational speed resolution, and the value at the intermediate rotational speed is determined by interpolation processing. 17. The waveform output from the fan control means is stopped in response to the command rotation speed and the actual rotation speed being equal to or less than the waveform output stop rotation speed during the rotation speed reduction operation.
The fan motor control method according to any one of claims 1 to 16. 18. The fan motor control method according to claim 17, wherein the waveform output stop rotation speed is set in accordance with the start-up and the normal operation. 19. The fan motor control method according to claim 18, wherein the waveform output stop rotation speed corresponding to the start is set to a value lower than the waveform output stop rotation speed corresponding to the normal operation. 20. When the waveform output is stopped, all the switching elements included in the fan control means are turned off.
The fan motor control method according to any one of claims 1 to 19. 21. The fan motor control method according to claim 1, wherein the fan motor drives a fan included in the air conditioner. 22. The fan motor control method according to claim 1, wherein the fan motor is a brushless DC motor. 23. Fan control means (2a) (2b)
(8) A drive means (7) for driving the fan motor (3) according to (9), wherein a load detection means (7) for detecting a load applied to the fan motor is provided. hand,
A command to decrease the command speed to be supplied to the fan control means (8) and increase the command speed to be supplied to the fan control means (8) in response to the detected load being smaller than the predetermined load. A fan motor control device comprising a rotation speed control means (7). 24. Fan control means (2a) (2b)
(8) A drive means (7) for driving the fan motor (3) according to (9), wherein a load detection means (7) for detecting a load applied to the fan motor is provided. Until it becomes smaller than the load, keep decreasing the command speed,
And a command speed control means (7) for continuously increasing the command speed after the detected load becomes smaller than the predetermined load. 25. The load detecting means (7) detects a load using a DC current value or a fan motor current value of a fan control means and a rotation speed of the fan motor. 3. The fan motor control method according to 1. 26. The fan motor according to claim 23, wherein the load detecting means detects an overload state in response to the detected load being equal to or more than a predetermined load. Control method. 27. The overload detecting means (7) detects an overload state in response to a current value being equal to or more than an overload determination value indicating an overload state, and detects a current value in an overload elimination state. 23. An overload elimination state is detected in response to a value having become equal to or less than a return determination value representing the following.
7. The fan motor control device according to any one of 6. 28. The fan according to claim 27, wherein the overload detection means includes a determination value setting means for setting at least one of an overload determination value and a return determination value according to a rotation speed. Motor control device. 29. The apparatus according to claim 28, wherein the determination value setting means (7) sets at least one of an overload determination value and a return determination value as the rotation speed increases and decreases as the rotation speed decreases. Fan motor control device. 30. The determination value setting means (7) sets at least one of an overload determination value and a return determination value to a value at the maximum use rotation speed in response to the rotation speed being equal to or higher than the maximum use rotation speed. 30. The fan motor control device according to claim 28, wherein: 31. The fan according to claim 28, wherein the determination value setting means (7) sets the overload determination value to a current value at a higher load as the rotational speed decreases. Motor control device. 32. The fan according to claim 28, wherein the determination value setting means (7) sets the overload determination value to a current value at a higher load as the rotation speed increases. Motor control device. 33. The judgment value setting means (7) sets an overload judgment value according to an operation range.
The fan motor control device according to any one of claims 8 to 30. 34. The overload detection means (7) determines an overload determination value at a maximum operating speed by a fan motor (3).
The fan motor control device according to any one of claims 23 to 33, wherein the fan motor control device is set to a value larger than a current value corresponding to a maximum load to be activated. 35. The apparatus according to claim 23, wherein the overload detecting means adopts a peak hold value, an average value, or an effective value as the DC current value or the fan motor current value. 3. The fan motor control device according to 1. 36. The command rotation speed control means (7) sets the degree of change in the set value of the command rotation speed to be longer than the settling time of speed control.
The fan motor control device according to any one of the above. 37. The command rotation speed control means (7) determines the degree of decrease in the set value of the command rotation speed by a fan control means (2a).
36. The fan motor control device according to claim 23, wherein the temperature rise is set to be lower than the temperature rise at which the fan breaks. 38. The overload detection means (7) sets a determination value for each value coarser than the rotational speed resolution, and determines a value at an intermediate rotational speed by an interpolation process.
The fan motor control device according to any one of claims 3 to 37. 39. The fan control means (8) stops the waveform output in response to the command rotation speed and the actual rotation speed being equal to or less than the waveform output stop rotation speed during the rotation speed reduction operation. 39. The fan motor control device according to claim 23. 40. The fan motor control device according to claim 39, wherein the fan control means (8) sets the waveform output stop rotation number according to whether the apparatus is being started or in normal operation. 41. The fan control means (8) for setting a waveform output stop rotation speed corresponding to during start-up to a value lower than a waveform output stop rotation speed corresponding to during normal operation. The fan motor control device according to the above. 42. The fan control means (9) for turning off all switching elements included in the fan control means (2a) when waveform output is stopped. Fan motor control device. 43. A fan motor (3) for driving a fan (3c) included in an air conditioner.
43. The fan motor control device according to claim 42. 44. The fan motor (3) is a brushless DC
The fan motor control device according to any one of claims 23 to 43, wherein the fan motor control device is a motor (3).