KR20100002783A - Sensorless blushless motor high-speed startup algorithm with smart align process - Google Patents

Abstract

PURPOSE: A method for starting a sensorless brushless motor is provided to prevent start vibration or delay by compensating for the phase of a stator according to a rotation direction and a stop/rotation state of a rotor. CONSTITUTION: A position of a rotor is detected and a rotation timer is operated(S1). The phase of a stator is changed according to the position of a rotor(S2). If the rotor stops, the stop state is compensated(S4). If the rotor rotates, the rotation direction is determined(S5). If the rotor rotates reversely, the reverse rotation is compensated(S6). If the rotor rotates forward, the rotation is tried using the counter electromotive force(S7). The rotation using the reverse electromotive force and the speed are controlled(S10).

Description

Sensorless Blushless Motor High-speed Startup Algorithm with Smart Align Process

The present invention relates to a high-speed start method of a sensorless brushless motor using intelligent alignment, detecting the position of the rotor and operating the rotation timer (S1), and changing the phase of the stator according to the detected position of the rotor. After that, the step of starting the rotation (S2) and whether it is in the stationary state or the rotation state is determined (S3), if the stop state is compensated (S4) to change the phase of the stator accordingly (S2) Returning to the step and, if the rotation state is determined in the direction of rotation (S5), if the reverse rotation state is compensated for the reverse rotation (S5) and accordingly changes to the phase of the stator (S2), if In the case of the forward rotation step (S7) and attempts to rotate using the counter electromotive force, and attempts to rotate using the counter electromotive force (S7) and then determine the direction of rotation (S8) when the reverse rotation compensation step (S6) Stone The method relates to a high-speed start method of a brushless motor using intelligent alignment, characterized in that it comprises a step and controlling the rotational duration and speed using the counter electromotive force (S10).

Unlike brushless DC motors, brushless motors have no commutator, so the position and rotation of the rotor are unknown. Therefore, brushless motors generally use sensors to sense and control the position and rotation of the rotor. However, in recent years, brushless motors have been generally used without sensors (sensorless) for reliable operation even in environments where price competition and sensors are difficult to use. The start of the sensorless brushless motor may be applied and used in various ways according to its technical characteristics. In one embodiment, there is a method of storing (memory) the memory based on the previous driving and starting it. However, this method is not applicable to a method in which the power is switched at every startup. There is a problem that the maneuver may fail if it is moved to a different position from the memorized position (EX. Pump: reverse rotation due to pressure, wind and flow rate).

On the other hand, as another embodiment of the conventional method for starting the sensorless brushless motor, there is a method of sequentially performing the following control methods when starting as shown in FIG.

① Position detection of rotor

② Forced alignment of the rotor and forced rotation in the target direction

③ Forced rotation repetition and speed increase until detection of available back EMF

④ Repeated counter electromotive force calculation and forced rotation repetition

⑤ Rotation check using counter electromotive force

⑥ Rotation duration and speed control using counter electromotive force

After the forced alignment of the sensorless brushless motor, the open-loop rotation is repeated, and the starting method of detecting and starting the counter electromotive force is used by a simple open loop or a complex closed loop depending on the control characteristics and the purpose of use. In this conventional method, the initial driving can be made simply by the open-loop control, and the advantage can be achieved by the simple control of the product having a constant starting load. However, such a conventional method may cause forced alignment to fail when the starting load is large, and if the starting load is not fluidly deterministic, the necessary maneuvering force cannot be determined after the forced alignment, and thus the starting failure after the alignment is often caused. When small, the vibration caused by the forced alignment is large, there is a problem that the time delay of the open loop section (rotation start point) is severe depending on the starting load.

In order to solve the above problems of the existing technology, the present invention eliminates the occurrence of starting failure or starting vibration that may occur in the process of forcibly aligning the rotor at the beginning of the start, the start in a closed loop method at a faster time The task is to make it possible to perform a quick and accurate operation by compensating for various problems which may be caused by a start time delay.

In order to achieve the above object, the high-speed start method of the sensorless brushless motor using the intelligent alignment of the present invention is to detect the position of the rotor and to operate the rotation timer (S1) and to the detected position of the rotor According to the step of changing the phase of the stator to start the rotation (S2), and it is determined whether the stationary state or the rotation state (S3), if the stop state is compensated for the stop state (S4) accordingly The step of returning to the step of changing (S2) and, if the rotation state is determined in the rotation direction (S5), if the reverse rotation state in the reverse rotation to compensate (S5) accordingly to change the phase of the stator (S2) Returning to the step, if the forward rotation (S7) attempts to rotate using the counter electromotive force, and attempts to rotate using the counter electromotive force (S7) and then determine the rotation direction (S8) if the reverse rotation state Reverse It is characterized in that it comprises a step of returning to the previous compensation step (S6), and a step (S10) for controlling the rotation duration and speed using the counter electromotive force.

In addition, after the step (S7) of attempting to rotate using the counter electromotive force and then determining the direction of rotation (S8), after the attempt to rotate using the counter electromotive force (S7), when the rotation direction is the forward rotation, the counter electromotive force is used. In the case of reverse rotation by verifying the rotation direction (S9), the method may further include returning to the reverse rotation compensation step (S6).

In addition, when the time of the timer specified in the operation of the rotation timer (S1) has elapsed, detecting the position of the initial rotor again and returning to the operation of the rotation timer (S1) and attempting to drive again. It is characterized in that it further comprises.

In addition, the stationary state compensating step (S4) is characterized in that it comprises a step of compensating the electric angle of the electrical signal transmitted to the stator to change the phase of the stator in the direction that can be rotated forward when the rotor is stopped. .

In addition, the reverse rotation compensation step (S6) is characterized in that it comprises a step of compensating the electric angle of the electrical signal transmitted to the stator to change the phase of the stator so that when the rotor rotates in reverse rotation It is done.

In addition, in the case of the three-phase two-excitation type brushless motor, the stationary state compensating step (S4) sets an electric angle of 60 degrees to an image of an electrical signal to be applied to the stator in a direction capable of forward rotation when the rotor is stopped. It is characterized by the compensation for each.

In addition, in the case of the brushless motor of the three-phase two-excited type, the reverse rotation compensating step (S6) is 60 degrees of the image of the electrical signal to be applied to the stator in the direction that the rotor can be rotated when the rotor is reversed Compensation for each electric angle.

According to the present invention, by simply combining the existing sensorless brushless motor driving circuit or simply changing the program of the processor in the driving circuit, even if the power is switched at every startup, the rotor position is not forcedly aligned with the mechanical rotor. And counter electromotive force is given priority, and the actual position of the rotor is estimated to change the phase of the stator so that even if the rotor is rotating in reverse when not in use (position change), starting is performed according to rotor position detection and counter electromotive force judgment. Therefore, there is less starting failure, and starting position is less likely to be changed regardless of starting load (closed loop). It has the advantage of high adaptability according to the load. In addition, it is possible to shorten the time to reach the closed loop control using the counter electromotive force, thereby enabling a fast start time.

Hereinafter, a high speed start method of a sensorless brushless motor using intelligent alignment according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, in the drawings, the same components or parts are to be noted that as indicated by the same reference numerals as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The present invention begins with a step S1 of first detecting the position of the rotor and starting the rotation timer, as shown in FIG. In this case, since the method of detecting the position of the rotor is widely used in the technical field to which the present invention belongs, detailed description thereof will be omitted.

Thereafter, the step S2 of starting the rotation after changing the phase of the stator according to the detected position of the rotor is performed. Thereafter, as shown in FIG. 2, it is determined whether the rotor is in a stationary state or a rotating state (S3), and if it is in the stopped state, the stationary state is compensated (S4) and thus the phase of the stator is changed (S2). Returning to the step, if the rotation state is determined in the direction of rotation (S5), if the reverse rotation state is compensated for the reverse rotation (S5) and accordingly change to the phase of the stator (S2), if the forward rotation is In the case of performing the rotation using the back EMF (S7) is performed. In the above process, the technology for detecting and determining the stop state of the rotor or the rotation state in the forward / reverse rotation direction analyzes the voltage change curve of the counter electromotive force generated during motor driving, and detects the forward, the direction and the stop state. Since it is a technique widely known and performed in the technical field regarding the sensorless brushless motor to which this invention belongs, detailed description is abbreviate | omitted. In addition, the method of changing the phase of the stator may have a difference in potential angle depending on the phase of the power source to be used, the winding structure of the stator to be used, and the number of poles of the rotor. The electrical angle of the signal is changed to a constant angle (for example, in the case of a three-phase two-excitation bounce), the electrical angle is changed to 60 degrees forward / return with respect to a desired driving direction. Since the technique is widely known and practiced in the technical field, detailed description thereof will be omitted. On the other hand, the stop state compensation step (S4) is a step of compensating the electric angle of the electrical signal transmitted to the stator to change the phase of the stator in the direction that can be rotated forward when the rotor is stopped, the reverse rotation compensation step S6 is a step of compensating the electric angle of the electrical signal transmitted to the stator to change the phase of the stator so that the rotor can perform a forward rotation when the rotor rotates in reverse.

As described above, the process of starting the sensorless brushless motor by compensating and changing the image of the stator according to the stop / rotation state and the rotation direction of the rotor is the core of the present invention. By compensating and changing the phase of the electric starting signal applied by the control circuit to make electrical alignment between the rotor and the stator, the position of the rotor in the existing invention by forcing the machine by force Mechanical movements can eliminate or reduce the likelihood of start-up vibrations, start-up delays or start-up failures caused by mechanical alignment. In addition, it is possible to eliminate the physical response delay between the electrical alignment and the mechanical alignment due to the mechanical alignment of the rotor according to the electrical starting signal applied to the stator, thereby enabling rapid startup.

Next, after the rotation is attempted using the counter electromotive force (S7), the rotation direction is determined (S8), and in the reverse rotation state, the process returns to the reverse rotation compensation step (S6). On the other hand, in the case of the forward rotation in order to ensure a more stable start-up using the counter electromotive force (S7) and then the rotation direction is verified by using the counter electromotive force (S9) in the case of the reverse rotation (S9), if the reverse rotation It is preferable to further perform the step of returning to the rotation compensation step S6. When the timer specified in the step S1 of operating the rotation timer has elapsed during this process, the controller detects the position of the initial rotor and returns to the step S1 of operating the rotation timer to restart the driving. It is desirable to try.

In this manner, after the forward rotation starts, the high speed start method of the sensorless brushless motor using the intelligent alignment of the present invention is completed through the step S10 of controlling the rotation duration and the speed using the counter electromotive force.

In the foregoing description, optimal embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a flowchart illustrating a method of starting a sensorless brushless motor according to an embodiment of the present invention.

2 is a flow chart of a high speed start method of a brushless motor using intelligent alignment according to an embodiment of the present invention.

Claims (7)

Detecting a position of the rotor and operating a rotation timer (S1); Starting the rotation after changing the phase of the stator according to the position of the rotor detected in the step (S2); Judging whether the rotor is in a stationary state or a rotating state (S3), and if it is in the stationary state, compensating for the stationary state (S4) and thus returning to changing the phase of the stator (S2); If the rotor is in the rotation state to determine the direction of rotation (S5), If it is in the reverse rotation state, the reverse rotation is compensated (S5) and accordingly changes to the phase of the stator (S2), and if it is the forward rotation, attempting to rotate using the counter electromotive force (S7); Attempting to rotate using the counter electromotive force (S7), and then determining the rotation direction (S8) and returning to the reverse rotation compensation step (S6) in the reverse rotation state; Performing rotation duration and speed control using the counter electromotive force (S10); High speed start method of a sensorless brushless motor using an intelligent alignment, characterized in that it comprises a. The method according to claim 1, After the step of attempting the rotation using the counter electromotive force (S7) and after determining the rotation direction (S8), Attempting to rotate using the counter electromotive force (S7) and when the rotation direction is the forward rotation, verifying the rotation direction using the counter electromotive force (S9) and returning to the reverse rotation compensation step (S6) when the reverse rotation is performed; A high speed start method of a sensorless brushless motor using intelligent alignment, characterized in that it further comprises. The method according to claim 2, Detecting the position of the initial rotor and attempting to drive again when the time of the timer specified in the operation of the rotation timer has passed (S1); A high speed start method of a sensorless brushless motor using intelligent alignment, characterized in that it further comprises. The method according to any one of claims 1 to 3, The stationary state compensating step (S4) comprises the step of compensating for the electric angle of the electrical signal transmitted to the stator to change the phase of the stator in the direction that can be rotated forward when the rotor is stopped, intelligent alignment High speed start method of sensorless brushless motor using The method according to claim 4, The reverse rotation compensating step (S6) is configured to compensate for the electrical angle of the electrical signal transmitted to the stator so that the rotor changes the phase of the stator in the direction that can be rotated forward when the rotor is rotated in reverse High speed start method of sensorless brushless motor using intelligent alignment. The method according to claim 5, The stop state compensating step (S4) is a three-phase two-excitation type brushless motor, in which the phase of the electrical signal to be applied to the stator in a direction capable of forward rotation when the rotor is stopped by an electric angle of 60 degrees. High speed start method of a sensorless brushless motor using intelligent alignment, characterized in that the compensation. The method according to claim 5, The reverse rotation compensating step (S6) is in the case of a brushless motor of the three-phase two-excitation type, the electric angle of 60 degrees to the phase of the electrical signal to be applied to the stator in the direction in which the rotor can be rotated forward when the rotor rotates in reverse A high-speed start method of a sensorless brushless motor using intelligent alignment, characterized in that by compensation.

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