CN105577037B - Fan starting control method and fan - Google Patents

Abstract

The present case discloses a fan startup control method and a fan. The fan startup control method is suitable for controlling a fan startup phase, and the fan startup phase includes a first time interval and a second time interval. The startup control method includes the following steps: continuously providing a first drive signal to drive the fan in the first time interval; and continuously providing a second drive signal to drive the fan in the second time interval. The signal value (drive energy) of the first drive signal gradually decreases in the first time interval until it is equal to the signal value of the second drive signal, and the initial value of the signal value of the first drive signal is greater than the signal value of the second drive signal. The present invention utilizes a first drive signal that gradually reduces energy, and controls the fan speed in an open-loop control phase in combination with a second drive signal, thereby reducing the phenomenon of fan speed overshoot, thereby effectively reducing startup noise, and can further adjust the startup capacity, without the need to continuously output higher energy, effectively saving electrical energy.

Description

Fan start control method and fan

technical field

The present invention relates to a start-up control method of a fan and the fan, in particular to a start-up control method of a three-phase fan in the start-up phase and the fan.

Background technique

In response to energy-saving requirements, the system of the notebook computer often switches between the sleep mode and the normal mode, so the fan will also frequently stop or restart corresponding to different working modes. However, when the fan restarts from a stopped state, it often produces obvious startup noise. The main reason for the startup noise is that when the fan restarts, it provides a fixed high-energy in the open loop (Open Loop) control stage. The driving signal is used to forcibly start the fan without using any sensor feedback signal to adjust the driving signal. However, the energy of the driving signal will affect the starting noise.

Please refer to Figure 1. Figure 1 is a schematic diagram of the driving signal, noise and rotational speed of the existing fan at the initial stage. The fan continues to increase the rotational speed according to the driving signal S, and the noise continues to increase. When the driving signal S drives the fan for a period of time Interval T _openloop , that is, after the impeller of the fan rotates smoothly and the fan speed reaches a threshold speed, the fan will switch to the closed loop (Close Loop) control stage, that is, in this stage, it will use a The feedback signal of the detection circuit adjusts the signal value of the drive signal (that is, the duty cycle (Duty Cycle) will be reduced from A to A'), and the fan is still running at a target speed, but it is often due to the change in the drive signal of the fan at the initial stage. If the energy is too large, the target speed of the fan is far lower than the threshold speed of the open-loop control stage, resulting in overshoot of the fan speed during the startup process, thus producing obvious startup noise.

Therefore, how to provide a fan startup control method and a fan that can effectively reduce the startup noise has become one of the important issues.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a fan startup control method and a fan that can effectively reduce the startup noise, so as to solve the problem of obvious noise in the initial stage of the fan.

According to the fan start-up control method of the present invention, it is applicable to the control of a fan start-up phase, and the fan start-up phase includes a first time interval and a second time interval. The startup control method includes the following steps: continuously providing a first driving signal to drive the fan in a first time interval; and continuously providing a second driving signal to drive the fan in a second time interval. Wherein, the signal value of the first driving signal decreases gradually until equal to the signal value of the second driving signal in the first time interval, and the initial value of the signal value of the first driving signal is greater than the signal value of the second driving signal.

In an embodiment, the signal value of the second driving signal is a fixed value.

In one embodiment, the fan includes an impeller, a motor, and a control circuit. The motor is respectively connected to the impeller and drives the impeller to run and is electrically connected to the control circuit. The control circuit includes a control unit and a detection unit, and the detection unit detects the current of the motor. Phase or counter electromotive force, and output a feedback signal to the control unit. The startup control method further includes: after reaching the fan startup phase, providing a third driving signal to drive the fan according to the feedback signal.

In one embodiment, the first driving signal, the second driving signal and the third driving signal are provided by the control unit.

In one embodiment, the first driving signal, the second driving signal and the third driving signal are pulse width modulation signals or DC voltage signals.

In an embodiment, the signal value of the first driving signal decreases linearly or decreases nonlinearly.

In an embodiment, the sum of the first time interval and the second time interval is a certain value.

A fan according to the present invention includes: an impeller, a motor and a control circuit; the motor is connected to the impeller and drives the impeller to run, and the motor is electrically connected to the control circuit. The control circuit includes a control unit, and the control unit provides a first drive signal and a second drive signal to drive the fan during the start-up phase of the fan; wherein, the start-up phase of the fan includes a first time interval and a second time interval, and the control unit The first driving signal is continuously provided to drive the fan in the first time interval, and the signal value of the first driving signal is gradually reduced in the first time interval; then until the signal value of the first driving signal is equal to the signal value of the second driving signal, The control unit continuously provides the second driving signal to drive the fan in the second time interval, and the initial value of the signal value of the first driving signal is greater than the signal value of the second driving signal.

In an embodiment, the signal value of the second driving signal is a fixed value.

In one embodiment, the control circuit further includes a detection unit, the detection unit detects the current phase of the motor or the counter electromotive force, and outputs a feedback signal to the control unit, and the control unit provides a The third driving signal is used to drive the fan.

To sum up, the start-up control method of the fan and the fan in the present invention use the first drive signal with gradually reduced energy and the second drive signal to control the fan speed in the open-loop control stage during the fan start-up stage, so as to reduce the excessive speed of the fan. The phenomenon of rushing can effectively reduce the starting noise, and the starting ability can be adjusted, and there is no need to continuously output high energy, which can effectively save electric energy.

Description of drawings

FIG. 1 is a schematic diagram of the working cycle, noise and rotating speed of the conventional fan at the initial stage.

FIG. 2 is a schematic block diagram of a fan according to a preferred embodiment of the present invention.

FIG. 3A is a schematic diagram of the duty cycle, noise and rotational speed of a preferred embodiment of the present invention.

3B to 3E are schematic diagrams of the first driving signal in FIG. 3A having different reduction modes.

Fig. 4 is a flow chart of the steps of the start-up control method of the preferred embodiment of the present invention.

Fig. 5 is a control flow chart of the startup control method of the preferred embodiment of the present invention.

Explanation of reference signs:

20: fan

21: impeller

22: motor

23: Control circuit

231: Control unit

232: detection unit

S: driving signal

S1: the first driving signal

S1A: Curve for linear reduction mode

S1B: Curve for Curved Lowering Mode

S1C: Curves for step-down mode

S1D: Curve combining curvilinear and linear reduction modes

S2: Second driving signal

S3, S3A, S3B: the third driving signal

S10, S20, S100, S200, S300, S400, S500: steps

T: Open loop time interval

T1: first time interval

T2: second time interval

T _openloop : time interval

Detailed ways

The fan start control method and the fan according to the preferred embodiments of the present invention will be described below with reference to the related drawings, wherein the same elements will be described with the same reference symbols.

Please refer to FIG. 2 , and FIG. 3A to FIG. 3E . FIG. 2 is a schematic block diagram of a fan according to a preferred embodiment of the present invention. FIG. 3A is a schematic diagram of the duty cycle, noise and rotational speed of a preferred embodiment of the present invention. 3B to 3E are schematic diagrams of different reduction modes of the first driving signal S1 of FIG. 3A .

Please refer to FIG. 2, the fan 20 includes an impeller 21, a motor 22 and a control circuit 23; wherein the motor 22 is a three-phase motor, and is respectively connected to the impeller 21 and the motor to be electrically connected to the control circuit 23, and according to the output of the control circuit 23 The driving signal drives the impeller 21 to run. In addition, the control circuit 23 includes a control unit 231 and a detection unit 232 . The control unit 231 provides a driving signal to drive the impeller 21 . The detection unit 232 detects the current phase or back electromotive force of the motor 22, and sends a feedback signal to the control unit 231, so that the control unit 231 adjusts the driving signal according to the feedback signal during the closed loop control stage. In addition, in other embodiments of the present invention, the control unit 231 and the detection unit 232 may jointly constitute the same component.

In order to reduce the starting noise and take into account the starting ability, the present invention adopts variable output control in the starting process of the open loop (Open Loop) control stage. Please refer to FIG. 2 and FIG. 3A , when the impeller 21 restarts from the state of stopping, the control unit 231 will continue to provide a first driving signal S1 in the first time interval T1 of the open-loop control stage. The driving motor 22 drives the impeller 21 to run. After the impeller 21 runs smoothly, the control unit 231 will continue to provide a second driving signal S2 to drive the impeller 21 in the second time interval T2 of the open-loop control stage. Wherein, the signal value of the first driving signal S1 is a relatively high output energy in the first time interval T1 and gradually reduces the output energy (the signal value decreases from B to B'), while the signal value of the second driving signal S2 is a constant output energy value (B'), and the initial value B of the signal value of the first driving signal S1 is greater than the signal value B' of the second driving signal S2, and the final value B' of the signal value of the first driving signal S1 is equal to the first The initial value B' of the signal value of the second drive signal S2; wherein, the initial value B of the signal value of the first drive signal S1 is the minimum startable duty cycle (Duty Cycle) of the fan 20, and the signal value of the second drive signal S2 The initial value B′ is the minimum work cycle of the fan 20 . In this embodiment, the first driving signal S1 and the second driving signal S2 can be PWM signals or DC voltage signals, and the signal value of the first driving signal S1 and the signal value of the second driving signal S2 can be preset Set in the control unit 231.

In addition, the sum of the above-mentioned first time interval T1 and the second time interval T2 is a constant value, that is, the open-loop time interval T of the open-loop control phase (ie, the fan startup phase), that is, between the first time interval T1 and the The second time interval T2 is in the open-loop control stage, and after the open-loop time interval T of the open-loop control stage, the closed-loop control stage is entered. Therefore, as shown in FIG. 3A, when the speed of the impeller 21 increases gradually until the time reaches the open-loop time interval T, the corresponding noise does not increase significantly, and because the signal value of the first driving signal S1 of the present invention is gradually reduced to The signal value of the second driving signal S2 (the signal value decreases from B to B′), therefore, the overshoot of the fan speed also disappears accordingly. In addition, the open-loop time interval T will vary with different types of fans, therefore, the designer must adjust the first time interval T1, the second time interval T2, and the first time interval T1 and the second time interval according to different types of fans. The sum of the interval T2 (the open-loop time interval T in the open-loop control stage) is used to make the fan 20 run stably and effectively reduce the start-up noise of the fan 20 during the fan start-up stage.

After the fan 20 runs stably, it enters the closed-loop control stage (i.e., the normal operation stage). At this time, the control unit 231 of the control circuit 23 starts to provide a third drive signal S3 to drive the motor 22 according to the feedback signal from the detection unit 232. The impeller 21 operates. In this embodiment, the signal value of the third drive signal S3 may be greater than the signal value of the second drive signal S2 (ie, the third drive signal S3A in FIG. 3A ), or equal to the signal value of the second drive signal S2 (ie, the signal value in FIG. 3A The third driving signal S3), or a signal value smaller than the second driving signal S2 (ie, the third driving signal S3B in FIG. 3A ), there is no other limitation in the present invention, and the designer can make adjustments according to actual needs. In other embodiments, after the end of the second time interval T2 (that is, the end of the open-loop control stage), the closed-loop control stage is entered, and the control unit 231 will provide the third drive signal S3 with the same magnitude as the second drive signal S2 to continuously drive The motor 22 drives the impeller 21 to run for a short period of time, and then the speed is adjusted according to the feedback signal output by the detection unit 232 . In other embodiments, the signal value of the second driving signal S2 (in the open-loop control phase) can be slightly higher or slightly lower than the signal value of the third driving signal S3 (in the closed-loop control phase), and the value of the second driving signal S2 can be changed at a small speed. Reduce switching noise when switching control modes.

In this embodiment, the signal value of the first driving signal S1 gradually decreases, and the mode of the gradual decrease can be a linear decrease mode or a nonlinear decrease mode, which is not limited in the present invention, and the designer can adjust it according to actual needs. The reduction mode of the above-mentioned first driving signal can refer to FIG. 3B to FIG. 3E , which can be the curve S1A (shown in FIG. 3B ) of the linear reduction mode, the curve S1B (shown in FIG. 3C ) of the curvilinear reduction mode, and the stepwise reduction mode. The curve S1C (shown in Figure 3D) of the lowering mode, or the curve S1D (shown in Figure 3E) of the combined curvilinear and linear lowering mode, the curves S1A-S1D of the above-mentioned various lowering modes can conform to parabola, double A curve, or any line segment in the form of a curve, so that the signal value of the first driving signal S1 decreases gradually within the first time interval T1.

Please refer to FIG. 4 . FIG. 4 is a flow chart of the steps of the start-up control method in a preferred embodiment of the present invention. The present invention is applicable to the control of the fan start-up stage, the fan start-up stage includes a first time interval and a second time interval, and the start-up control method at least includes the following steps: continuously providing a first driving signal in the first time interval to drive the fan ( Step S10); and, continuously provide a second driving signal to drive the fan in the second time interval; wherein, the signal value of the first driving signal gradually decreases until it is equal to the signal value of the second driving signal in the first time interval, the second The initial value of the signal value of a driving signal is greater than the signal value of the second driving signal (step S20).

In step S10, the signal value of the first driving signal S1 gradually decreases in the first time interval T1, and the mode of its gradual decrease may adopt a linear decrease mode or a non-linear decrease mode, which is not limited in the present invention, and the designer can according to Adjust to actual needs.

In addition, in step S20 of this embodiment, the signal value of the second driving signal S2 is a fixed value. In other embodiments, the signal value of the second driving signal S2 can gradually decrease or increase gradually, which is not intended to be used in the present invention. The designer can adjust it according to actual needs. In addition, the length of the second time interval T2 can be adjusted according to the stable running time of the fan, which is not limited in the present invention, and the designer can adjust it according to the stable running time of the fan.

In this embodiment, the first driving signal S1 and the second driving signal S2 can be PWM signals or DC voltage signals, which are not limited in the present invention, and designers can adjust them according to actual needs. In addition, the initial value B of the signal value of the first drive signal S1 is the minimum startable duty cycle (Duty Cycle) of the fan 20, that is, the torque provided by the first drive signal S1 to the fan must be greater than the maximum static friction of the fan 20, because Due to the difference in fan structure, the maximum static friction of the fan 20 will be different. In addition, the initial value B' of the signal value of the second driving signal S2 is the minimum operable duty cycle of the fan 20, that is, the torque provided by the second driving signal S2 to the fan must be greater than the dynamic friction force of the fan 20 during operation, so the first The first driving signal S1 and the second driving signal S2 must be adjusted according to different fan structures and motors, which is not limited by the present invention.

Please refer to FIG. 5 . FIG. 5 is a control flow chart of a start-up control method according to a preferred embodiment of the present invention. The present invention is applicable to the control of the fan start-up stage, and the control flow of the start-up control method includes at least the following steps: providing a first drive signal to drive the fan (step S100); judging whether the signal value of the first drive signal is equal to the signal of the second drive signal value (step S200). If not, decrease the signal value of the first driving signal (step S300); if yes, provide the second driving signal to drive the fan (step S400); then, determine whether the driving time reaches the open-loop time interval (step S500).

In step S100, a first drive signal is provided to drive the fan; after a predetermined time period, step S200 is executed, that is, after a predetermined time period, it is judged whether the signal value of the first drive signal is equal to The signal value of the second drive signal.

In step S200, if the signal value of the first driving signal is not equal to the signal value of the second driving signal, then perform step S300, that is, reduce the signal value of the first driving signal, and reduce the signal value of the first driving signal After the value is set, step S100 is then performed to drive the fan with the reduced first driving signal. In addition, in step S200, if the signal value of the first driving signal is equal to the signal value of the second driving signal, then execute step S400, that is, provide the second driving signal to drive the fan, and finally execute step S500.

In step S500, it is necessary to determine whether the driving time reaches the open-loop time interval T. If the driving time reaches the open-loop time interval T, the fan open-loop control stage is completed, and then enters the closed-loop control stage; if the driving time has not yet reached the open-loop time interval T, step S400 is executed.

In this embodiment, the signal value of the first driving signal S1 will gradually decrease in the first time interval T1, and the time required for the signal value of the first driving signal S1 to drop to the signal value of the second driving signal S2 is The aforementioned first time interval T1. In addition, since the sum of the aforementioned first time interval T1 and the second time interval T2 is a constant value, that is, the open-loop time interval T (the sum of the first time interval T1 and the second time interval T2) is a constant value. Since the open-loop time interval T is a constant value, the second time interval T2 is after the first time interval T1, and then continues to drive the fan with the second driving signal S2 until reaching the time interval of the open-loop time interval T.

To sum up, the start-up control method of the fan and the fan in the present invention use the first drive signal with gradually reduced energy and the second drive signal to control the fan speed in the open-loop control stage during the fan start-up stage, so as to reduce the excessive speed of the fan. The phenomenon of rushing can effectively reduce the starting noise, and the starting ability can be adjusted, and there is no need to continuously output high energy, which can effectively save electric energy.

The above descriptions are illustrative only, not restrictive. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the appended claims.

Claims (8)

1. A start-up control method of a fan, suitable for the control of a fan start-up phase, the fan start-up phase is an open-loop control phase, and the fan start-up phase is successively composed of a first time interval and a second time interval, wherein It is characterized in that the startup control method includes the following steps: Continuously providing a first driving signal to drive the fan during the first time interval of the open-loop control phase; and Continuously providing a second driving signal to drive the fan during a second time interval of the open-loop control phase; Wherein, the fan directly enters the first time interval of the fan starting phase from the stopped state, the signal value of the first driving signal gradually decreases until it is equal to the signal value of the second driving signal in the first time interval, the second The initial value of the signal value of a driving signal is greater than the signal value of the second driving signal, the signal value of the second driving signal is a fixed value, and the first driving signal and the second driving signal are pulse width modulation signals , or DC voltage signal. 2. The starting control method according to claim 1, wherein the fan comprises an impeller, a motor and a control circuit, the motor is connected to the impeller and drives the impeller to run, and the motor is electrically connected to the control circuit , the control circuit includes a control unit and a detection unit, the detection unit detects the current phase or counter electromotive force of the motor, and outputs a feedback signal to the control unit, and the start control method also includes: After reaching the fan starting stage, according to the feedback signal, a third driving signal is provided to drive the fan. 3. The startup control method according to claim 2, wherein the first driving signal, the second driving signal and the third driving signal are provided by the control unit. 4. The starting control method according to claim 2, wherein the third driving signal is a pulse width modulation signal or a DC voltage signal. 5. The starting control method according to claim 1, wherein the signal value of the first driving signal decreases linearly or decreases non-linearly. 6. The starting control method according to claim 1, wherein the sum of the first time interval and the second time interval is a certain value. 7. A fan, characterized in that it comprises: an impeller; a motor, connected to the impeller, and drives the impeller; and A control circuit electrically connected to the motor, including: A control unit provides a first driving signal and a second driving signal to drive the fan during a fan starting phase; Wherein, the fan start-up phase is an open-loop control phase, and the fan start-up phase is sequentially composed of a first time interval and a second time interval, and the control unit continues to provide the second time interval during the first time interval of the open-loop control phase. A drive signal to drive the fan, and the fan directly enters the first time interval of the fan starting phase from the stop state, and the signal value of the first drive signal gradually decreases in the first time interval until the first drive signal The signal value of the second drive signal is equal to the signal value of the second drive signal, the control unit continues to provide the second drive signal to drive the fan during the second time interval of the open-loop control stage, and the signal value of the first drive signal The initial value is greater than the signal value of the second driving signal, the signal value of the second driving signal is a fixed value, and the first driving signal and the second driving signal are pulse width modulation signals or DC voltage signals. 8. The fan according to claim 7, wherein the control circuit further comprises: A detection unit detects the current phase or counter electromotive force of the motor, and outputs a feedback signal to the control unit, and the control unit provides a third drive signal to drive the fan after reaching the start-up stage of the fan according to the feedback signal fan.