JP3420038B2 - DC motor drive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless DC motor drive device for driving a fan or the like.

[0002]

2. Description of the Related Art Conventionally, a DC motor drive device of this type is
A Hall element is used as a position detection element that detects the rotational position of the rotor, and the changes in the position detection signals from these multiple position detection elements are captured, and a plurality of predetermined switchings are performed according to the state of the position detection signal at that time. A general method is to drive the elements so that they turn on and off, and sequentially energize a plurality of stator windings to rotate the rotor (rectangular wave 120 degrees energization).

By the way, in such a driving method, if the current drops at the moment of switching the energization to the plurality of stator windings, the driving torque also drops, which leads to the generation of vibration and noise.

On the other hand, conventionally, the position detection signal change time interval from the change of one of the position detection signals obtained from a plurality of position detection elements to the change of the next position detection signal is the current overlap from the predetermined electrical angle. The first state of the combination of ON and OFF of a plurality of switching elements which is predetermined according to the state of the position detection signal at that time by calculating the elapsed time, capturing the change in the position detection signal from the plurality of position detection elements After a lapse of the energization overlap time, the energization is performed so as to be in a second state of a combination of ON and OFF of a plurality of switching elements which is predetermined according to the state of the position detection signal at that time. By overlapping the periods, the current does not drop at the moment of switching the energization, and vibration and noise are prevented (Patent Fair 6-
No. 52997, Japanese Patent Laid-Open No. 9-51690).

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In a motor drive device, due to variations in the positions, angles, etc. of individual position detection elements, one of the rotor position detection signals obtained from a plurality of position detection elements changes until the next one changes. Since the position detection signal change time interval of 3 is likely to vary, an error occurs in the overlapping time of energization, and the control stability was not reliable.

Further, the position detecting element is mounted on an electronic circuit board and fixed to a stator for detecting the position of the rotor, and a plurality of predetermined position detecting elements are used in consideration of changes in the position detecting signal of the position detecting element. Since it is driven so as to be in the first state of the ON / OFF combination of the switching elements of, the position detection element position must be changed in order to change the output timing of the ON / OFF combination of the switching elements at this time. In other words, it is necessary to change the position of the electronic circuit board fixed to the stator, and it is possible to easily adjust the optimum drive timing individually in each operating state such as startup, operation and reverse rotation. There is a problem such as no, and improvement of this is required.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a DC motor drive device capable of improving control stability and reliability.

[0008]

In order to achieve the above object, the DC motor driving device of the present invention is fixed to a stator.
A plurality of position detecting elements mounted on the electronic circuit board for detecting the position of the rotor, a plurality of switching elements connected to the plurality of stator windings for sequentially energizing in a predetermined direction and order, and the position detecting element. Signal change time interval measuring means for measuring the signal change time interval from the change of the signal obtained from the position detection signal of the element to the next change, and the predetermined conduction overlap electrical angle and the signal change time interval. The energization overlap elapsed time calculating means for calculating the energization overlap elapsed time and the change in the position detection signals of the plurality of position detection elements are detected, and a predetermined switching element is turned on according to the state of the position detection signal at that time. , The first state of OFF is output, and the switching element determined in advance according to the state of the rotor position detection signal at that time after the energization overlap time has elapsed. ON, the switching element ON and outputting a second off, a DC motor drive system including an off signal generating means, said signal change time interval measuring means, among the plurality of position detecting elements, the particular Done 1
The configuration of a DC motor drive device is characterized in that the time interval is measured by capturing only the signal change of each position detection element.

According to the present invention, it is possible to obtain a DC motor in which the stability of control at the time of starting and during operation is improved.

Further, another means is an energization overlap elapsed time calculating means for calculating a first energization overlap elapsed time and a second energization overlap elapsed time from the determined first and second energization overlap electrical angles. And after detecting a change in a plurality of position detection signals, outputs a first ON / OFF state of a plurality of switching elements, which is predetermined according to the state of the position detection signals at the time after the first energization overlap elapsed time. After the second energization overlap time has elapsed, a switching element that is predetermined according to the state of the rotor position detection signal at that time is turned on,
The switching element ON / OFF signal generating means for outputting the OFF second state is provided.

According to the present invention, it is possible to obtain a DC motor in which the stability of control at the time of start-up and during operation is improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a plurality of position detecting elements for detecting the position of a rotor, and a plurality of switching elements connected to a plurality of stator windings for respectively sequentially energizing them in a predetermined direction and order. , A specific one of the plurality of position detecting elements
Signal change time interval measuring means for measuring the signal change time interval from the change of the signal obtained from the position detection signals of the individual position detection elements to the change of the next signal, and a predetermined energization overlapping electrical angle and An energization overlap elapsed time calculating means for calculating an energization overlap elapsed time obtained from the signal change time interval and a change in the position detection signals of the plurality of position detection elements are detected, and predetermined according to the state of the position detection signal at that time. A first ON / OFF state of the plurality of switching elements is output, and a second ON / OFF state of the switching elements, which is predetermined according to the state of the rotor position detection signal at that time after the energization overlap time, is output. A switching element ON / OFF signal generating means for outputting a state is provided, and a position of a specific one of the plurality of position detecting elements is detected. Since there is a signal change time interval measuring means that measures the signal change time interval from the change of the signal obtained from the output signal to the change of the next signal, the position and angle of each position detecting element can be mounted One of the rotor position detection signals obtained from a plurality of position detection elements due to variations
It is possible to absorb the variation included in the rotor position detection signal change time interval from one change to the next one change, and reduce the error occurrence included in the energization overlap elapsed time to stabilize the control. You can secure the sex.

Further, from the determined first and second energization overlap electrical angles, the first energization overlap elapsed time and the second
The change in the position detection signal of the position detection element is detected from the elapsed time of the energization overlap of, and after the first elapsed time of the energization overlap, the plurality of switching elements are turned on and off which are predetermined according to the state of the position detection signal at that time. Switching element ON which outputs the first state and outputs the second state of ON and OFF of the switching element which is predetermined according to the state of the rotor position detection signal at that time after the second energization overlap elapsed time A plurality of switching elements which are provided with an off signal generating means and which are capable of detecting a change in the position detection signal of the position detection element and which have been determined in advance according to the state of the position detection signal at the time after the first energization overlap elapsed time. The first ON / OFF state is output, and after the second energization overlap elapsed time, the rough state is output according to the state of the rotor position detection signal at that time. Since the switching element ON / OFF signal generating means for outputting the ON / OFF second state of the predetermined switching element is provided, the timing for outputting the ON / OFF first state of the switching element is arbitrary. Since it can be changed to, it is possible to individually adjust the optimum energization timing in each operating state.

[0014]

Embodiments of the present invention will be described below with reference to FIG.

As shown in FIG. 1, a brushless DC motor 1 comprises stator windings U, V, W, a rotor (permanent magnet), and a Hall element mounted on an electronic circuit board for detecting the magnet position. The position detecting element 2 (Hu, Hv, Hw).

Qu-, Qu +, Qv-, Qv +, Qw-, and Qw + are switching elements 7, which sequentially energize the stator windings U, V, and W at predetermined timings.

The signal change time interval measuring means 3 changes the signal obtained from the position detection signal of one specific position detection element Hu of the plurality of position detection elements 2 (Hu, Hv, Hw), and then next. Measure the signal change time interval until the signal changes.

The energization overlap elapsed time calculating means 4 calculates the energization overlap elapsed time corresponding to the determined electrical angle based on the signal change time interval at that time.

The switching element ON / OFF signal generating means 5 detects changes in the position detection signals of the plurality of position detection elements 2 and applies predetermined directions to the plurality of stator windings in accordance with the state of the position detection signals at that time. And outputs a first ON / OFF state of the plurality of switching elements that is predetermined so as to sequentially energize in sequence, and predetermined according to the state of the rotor position detection signal at the time after the energization overlap time has elapsed. The second state of turning on and off of the switching element is output.

The signal change time interval measuring means 3,
The energization overlap elapsed time calculating means 4 and the switching element ON / OFF signal generating means 5 are built in the microcomputer, and the drive means 6 receives the signal from the microcomputer 8 and the Qu-, Qu +,
It is configured to supply current to the bases of Qv-, Qv +, Qw-, Qw +.

(Embodiment 1) FIG. 2 and FIG.
The operation will be described based on.

2 and 3, the position detecting element 2H
When the combination of outputs of u, Hv, and Hw changes from a certain combination such as (L, H, L) to (L, H, L) again, the electrical angle is 360 degrees, and from one combination to the next combination such as ( The time from L, H, L) to (L, H, H) is 60 electrical degrees.

The signal change time interval measuring means 3 has a specific
The signal obtained from the position detection signal of each of the position detection elements Hu changes from L to H, and then the signal changes from H to L.
The signal change time interval T1n before changing to, that is, the time required for the brushless DC motor to rotate 180 degrees in electrical angle is measured.

The energization overlap elapsed time calculating means 4 is calculated when the combination of the outputs of the position detecting elements 2Hu, Hv, Hw is in the state of (L, H, L), for example, and a predetermined electrical angle, for example, α = 30 degrees. The elapsed time of energization, which corresponds to, for example, T2n, is calculated from the following equation based on the signal change time interval T1n at that time, since T1n corresponds to an electrical angle of 180 degrees.

[0025]

[Equation 1]

The switching element ON / OFF signal generating means 5 detects changes in the position detection signals of the plurality of position detection elements 2Hu, Hv, Hw, for example (L, H, L) to (L, H, H), and detects the position at that time. A first ON / OFF of the plurality of switching elements, which is predetermined so as to sequentially energize the plurality of stator windings in a predetermined direction and order according to the state (L, H, H) of the detection signal. Is the state of u
-, U +, v-, v +, w-, w + H and L states (L, H, H, L, H, L) (hereinafter, shown as the left)
Is output, and after the energization overlap elapsed time T2n calculated by the energization overlap elapsed time calculation means 4 is turned on, a switching element predetermined according to the state (L, H, H) of the rotor position detection signal at that time, The second state of OFF (L, H, H, H, H, L) is output.

The drive means 6 is a microcomputer 8
Of the switching element 7 receiving the signals u-, u +, v-, v +, w-, w + from the switching element on / off signal generating means 5 incorporated in the switching element 7, and Qu-, Qu +, Qv-, Qv of the switching element 7.
Supply current to the bases of +, Qw-, and Qw + and turn on when L,
When it is H, it is turned off, and for example, the state of the first output (L,
H, H, L, H, L) corresponding to Qu-, Qu +, Qv-, Q
The on / off states of v +, Qw-, and Qw + are set to (on, off, off, on, off, on) (hereinafter, represented as the left), and the second output state (L, H, H, (ON, OFF, OFF, OFF, OFF, ON) corresponding to (H, H, L).

Next, a plurality of position detecting elements 2Hu, Hv, Hw
The position detection signal of (L, H, H) changes from (L, H, H) to (L, L, H) and switches according to the state (L, L, H) of the position detection signal at that time as shown in FIG. An element on / off signal and a switching element on / off state are output, and the next state is output in the same manner to sequentially energize a plurality of stator windings to rotate the rotor.

(Embodiment 2) FIGS. 4 and 5 in the above configuration.
The operation will be described based on.

4 and 5, the energization overlap elapsed time calculating means 4 is calculated and determined when the combination of outputs of the position detecting elements 2Hu, Hv, Hw is, for example, (L, H, L). A first energization overlap elapsed time, for example, T2n corresponding to the first electrical angle, for example, α = 20 degrees, is calculated from the following equation based on the signal change time interval T1n at that time.

[0031]

[Equation 2]

A second electrical angle defined next, for example β =
Second energization overlap elapsed time corresponding to 50 degrees, for example, T
3n is calculated from the following equation based on the signal change time interval T1n at that time.

[0033]

[Equation 3]

The switching element ON / OFF signal generation means 5 detects changes in the position detection signals of the plurality of position detection elements 2Hu, Hv, Hw, for example, from (L, H, L) to (L, H, H), and detects the position at that time. After a lapse of the first energization overlap elapsed time T2n calculated by the energization overlap elapsed time calculating means 4 in accordance with the state (L, H, H) of the detection signal, a predetermined direction is applied to each of the plurality of stator windings. U-, u +, v-, which are first states of ON and OFF of the plurality of switching elements, which are predetermined so as to sequentially energize in order,
v +, w-, w + H and L states (L, H, H, H ,
H, L) is output, and after the energization overlap elapsed time T3n represented by the following equation, ON / OFF of the switching element predetermined according to the state (L, H, H) of the rotor position detection signal at that time is output. The second state (L, H, L , H,
H, L) is output, and the following is the same as in the first embodiment.

[0035]

As is apparent from the above embodiments, from the time when the signal obtained from the position detection signal of a specific one of the plurality of position detecting elements changes until the next signal changes. Since the signal change time interval measuring means for measuring the signal change time interval is provided, the rotor position detection signal obtained from a plurality of position detection elements due to mounting variations such as the position and angle of each position detection element Since it is possible to absorb the variation included in the rotor position detection signal change time interval from the change of one to the change of the next one, the occurrence of the error included in the energization overlap elapsed time is reduced, and the control is reduced. It is possible to provide a DC motor drive control device capable of ensuring the stability of

The first ON / OFF of a plurality of switching elements, which is predetermined according to the state of the position detection signal at the time after the first energization overlap time, is detected by detecting a change in the position detection signal of the position detection element. Output the status of
A switching element ON / OFF signal generating means is provided for outputting a second ON / OFF state of the switching element which is predetermined according to the state of the rotor position detection signal at that time after the second energization overlap time has elapsed. Since it is possible to arbitrarily change the timing of outputting the first state of turning on and off of the switching element, a DC motor drive control device capable of individually adjusting the optimal energization timing in each state of operation is provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a DC motor drive device of the present invention.

FIG. 2 is a timing chart showing an example of drive waveforms according to the first embodiment of the present invention.

FIG. 3 is a table diagram showing ON / OFF states of the switching element.

FIG. 4 is a timing chart showing an example of drive waveforms according to a second embodiment of the present invention.

FIG. 5 is a table diagram showing ON / OFF states of the switching element.

[Explanation of symbols]

1 Brushless DC motor 2 Position detection element 3 Signal change time interval measuring means 4 Electric current overlap elapsed time calculation means 5 Switching element ON / OFF signal generation means 6 drive means 7 switching elements 8 microcomputer

Claims (2)

(57) [Claims] 1. Mounting on an electronic circuit board fixed to a stator
A plurality of position detecting elements for detecting the position of the rotor is, a plurality of switching elements for sequentially energizing each connected to a plurality of stator windings predetermined direction and order, the position detection signal of the position detecting element The signal change time interval measuring means for measuring the signal change time interval from the change of the obtained signal to the next change, and the conduction overlap elapsed time obtained from the predetermined conduction overlap electrical angle and the signal change time interval And a first ON / OFF of the switching element which is determined in advance in accordance with the state of the position detection signal at the time of detecting the change in the position detection signals of the plurality of position detection elements The state of the switching element is output, and after the passing time of the energization, the ON / OFF of the switching element which is predetermined according to the state of the rotor position detection signal at that time is output. Switching element on the output of the state, a DC motor drive system including an off signal generating means, said signal change time interval measuring means, among the plurality of position detecting elements, identified a single position detecting element A DC motor drive device characterized in that it measures only the signal change of the above and measures the time interval. 2. An energization overlap elapsed time calculating means for calculating a first energization overlap elapsed time and a second energization overlap elapsed time from the determined first and second energization overlap electrical angles, and a plurality of A plurality of switching elements, which are predetermined in accordance with the state of the position detection signal at that time after the first energization overlap elapsed time by catching a change in the position detection signal,
Switching that outputs the first state of OFF and outputs the second state of ON and OFF of the switching element that is predetermined according to the state of the rotor position detection signal at the time after the second energization overlap elapsed time 2. The DC motor drive device according to claim 1, wherein the energization overlap is realized by providing an element on / off signal generating means.