KR100338010B1 - A brushless dircect current motor without sense and thereof method for diriving it - Google Patents

Abstract

The present invention provides a sensorless non-ELD motor driving method that detects the position of the rotor in a state where no back EMF is generated so that the driving of the motor is stabilized.

To this end, the sensorless non-ELD motor method of the present invention applies a current to a three-phase coil at the same time when the motor stops, so that magnetic and mutual inductances are generated in each coil, and the current of each coil with respect to the generated magnetic and mutual inductances is calculated. By detecting and comparing the currents of the detected coils with each other, a predetermined comparison result is obtained. As a result of this comparison, the position of the rotor is detected and the motor is driven corresponding to the detected position of the rotor.

Description

Sensorless Bieldic Motor and its driving method {A BRUSHLESS DIRCECT CURRENT MOTOR WITHOUT SENSE AND THEREOF METHOD FOR DIRIVING IT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blushless direct current (BLDC) motor, and more particularly to a non-dirty motor without a sensor.

Bieldish motor is designed to remove the brush that acts as commutator in general DC motor and to maintain the properties of DC motor. It consists of rotor, three-phase coil (U-phase coil, V-phase) Coil, W-phase coil), rotor made of permanent magnet, and position detection sensor.

The BLDC motor rotates the rotor by flowing a current through each phase of the stator side coil of the three-phase BLD motor and causing a magnetic field to be generated by the current. At this time, the BLDC motor detects the strength of the rotor's magnetic field, and the rotor continues in one direction by sequentially turning on and off switching elements for changing the direction of the current flowing in each phase of the coil according to the detected magnetic field. Rotate

In this way, the BLDC motor solves the problem of the DC motor by not using a brush, and replaces the position detection of the rotor, which is performed by the brush, with the intensity of the magnetic field of the rotor. , A hall sensor, a resolver, a photo-encoder, or the like. However, the BLDC motor as described above has a disadvantage in that the price of the motor driving circuit is increased and the reliability of the driving circuit is lowered because the position detection sensor must be used for the rotor position detection.

Therefore, in recent years, many methods for driving a brushless three-phase DC motor by indirectly detecting the position of rotation using a back electromotive force of the motor without using a position detection sensor such as a hall element have been used. However, the brushless 3-phase DC motor has the rotor angular velocity (ωr) of '0' and the counter electromotive force is '0' according to Equation 1 which calculates the counter electromotive force of the motor when the motor is in the stopped state. Therefore, there is a problem that can not use the back electromotive force.

Where Ve is the counter electromotive force voltage, Ke is the counter electromotive force constant, and ω r is the rotor angular velocity (rad / sec).

Due to this problem, in a system that wants to use the back electromotive force of the motor, the system can operate normally only when the motor rotates more than a predetermined speed. This acts as a burden to maintain a certain rotation speed because the back electromotive force is low even when the rotation speed of the motor is very low. Therefore, a system for driving a brushless DC motor using counter electromotive force adopts a method in which the switching elements of the three-phase inverter move the motor a little in a preset order when the motor is in a stopped state. Since there is no information on the position of the former, the three-phase inverter can be driven arbitrarily, which can cause the motor to fail to start and fail to drive the motor in a desired direction.

Therefore, the present invention aims to solve the above problems, so that the motor can be rotated in the required direction when the motor is driven or not operated at a predetermined speed or less so that the motor can be precisely controlled even in the absence of back electromotive force.

1 is a conceptual diagram of a sensorless BCD motor according to an embodiment of the present invention.

2A and 2B are timing diagrams of main output signals outputted from the respective parts of the sensorless BLD motor according to the embodiment of the present invention.

Fig. 3 is a switching pattern diagram of an inverter circuit for driving a sensorless BCD motor according to an embodiment of the present invention.

FIG. 4 is a diagram simulating inductance occurring in a three-phase coil of a sensorless BCD motor according to an embodiment of the present invention.

FIG. 5 is a timing diagram in which a sensorless BCD motor detects the position of the rotor using a back EMF waveform according to an embodiment of the present invention.

FIG. 6 is a first simulation diagram for detecting the rotor position of a sensorless BCD motor according to an embodiment of this invention.

FIG. 7 is a second simulation diagram for detecting the rotor of a sensorless BCD motor according to an embodiment of this invention.

8 is a flow chart of operation of a sensorless BLD motor in accordance with an embodiment of the present invention.

Bieldi motor according to a feature of the present invention for achieving the above object is a stator; Rotor; An inverter unit; It includes a commutation unit. The stator is formed of a three-phase coil formed at intervals of 120 °, and the rotor is made of magnetic material having different polarities to replace the stator. The inverter unit limits the current applied to the three-phase coil so that the current is applied to the corresponding two-phase coil of the three-phase coil. The rectifier controls the inverter to control the motor to rotate at a constant speed.

Through the above configuration, the BLD motor according to the characteristics of the present invention is stably driven when the motor rotates at a constant speed. When the motor is stopped during initial driving, the position of the rotor is detected without a position detection sensor. The magnetic inductance and mutual inductance of the three-phase coils are varied depending on the position of the motor rotor to induce rotation in the direction to detect the position of the rotor when the motor is stopped. That is, when a current is applied to the coil, the coil generates a magnetic inductance. At this time, if there is a magnetic body around the coil, the coil is affected by the magnetic body and the magnetic inductance value changes. Accordingly, in the three coils as described above, the magnetic inductances have different values according to the polarity and position of the rotor, and thus mutual inductances between the coils are different.

Therefore, in order to use the above principle, the BLD motor according to the characteristics of the present invention applies the current to the three-phase coil at the same time when stopped and compares the current passing through the three-phase coil with each other. Get location information. At this time, the coil of the phase in the position close to the rotor is affected by the magnetic field of the rotor, so the change of current flows large, and the coil of the phase in the position far from the rotor is less affected by the magnetic field of the rotor. Therefore, the change in current is small. Therefore, the result of comparing the currents of the respective phases shows two states, the first output state has two outputs in the low state and one output in the high state, and the outputs of the low state have one output in the low state. And two high outputs. In this output state, the Bildish motor according to this aspect of the invention detects the position of the rotor.

Meanwhile, in order to obtain more accurate position information of the rotor, the BLD motor according to the aspect of the present invention performs a position detection section of the rotor in a section having a large difference between the first to third output states. To this end the invention further comprises masking means.

Therefore, the sensorless BELDI motor according to the first aspect of the invention

A motor unit including a rotor having a magnetic pole sequentially arranged and a stator including a three-phase coil; A startup unit for applying a driving start signal for a predetermined time; A switch unit which turns on according to a driving start signal of the startup unit and outputs a first signal, and when the counter electromotive force generated in the motor unit is higher than a predetermined level, the switch unit turns off and outputs a second signal; Drives according to the driving start signal of the startup unit to control the current applied to the motor unit according to the first control mode, the second control mode and the third control mode, the first control mode detects the position of the rotor In order to simultaneously apply a current to each coil for a predetermined time to the position detection mode, the second control mode is an initial drive mode for driving the motor unit in consideration of the position of the detected rotor, the third control mode is Rectifying unit in the normal mode for controlling the motor to rotate at constant speed; An inverter circuit for changing a current direction applied to the three-phase coil according to different switching signals applied by the first, second, and third control modes of the rectifier; A comparator for comparing currents flowing in respective phases of the three-phase coils with each other and outputting a comparison result to the rectifier; And a mask unit configured to output a signal for varying an operation enable period of the rectifier according to the output of the switch unit in the position detection mode to the rectifier.

On the other hand, the sensorless Bieldi motor according to the second aspect of the present invention,

A first step of generating mutual inductance between all three-phase coils and the rotor according to the driving start signal generated for a predetermined time; A second step of detecting a position of the rotor by comparing currents of the three-phase coils according to mutual inductances generated in the first step with each other; A third step of driving the motor to a constant speed in consideration of the position of the rotor obtained in the second step; And a fourth step of controlling the direction of the current applied to the three-phase coil as the counter electromotive force of the motor rotating at a constant speed to operate the motor at constant speed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a sensorless BLD motor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram of a sensorless BCD motor according to an embodiment of the present invention. As shown in FIG. 1, the sensorless BCD motor according to the embodiment of the present invention includes a startup unit 100, a switch unit 200, a mask unit 300, a rectifier 400, an inverter circuit 500, The motor unit 600 and the comparison unit 700 is included.

Here, the motor unit 600 is a stator 610 composed of U-phase, V-phase, and W-phase coils (U, V, W) having a 120 ° phase difference, and a circuit formed of a plurality of magnetic poles surrounding the stator 610. Electron 620.

The startup unit 100 outputs a driving start signal S1 to the switch unit 200, the mask unit 300, and the rectifier 400.

The switch unit 200 is turned on by the current source IS1 connected to the reference voltage Vref, the driving start signal S1 of the start-up unit 100, and the switch SW and the switch whose one end is connected to the current source IS1. The other end of SW is connected to one end and the other end is grounded with a current comparator (R), a non-inverting terminal is connected to the contact point of the switch SW and the resistor R, and an output end is connected to an input terminal of the mask unit 300 ( COM), and a current amplifier AMP connected to two input terminals of the motor unit 600 and an output terminal of the current comparator COM1.

Accordingly, the switch unit 200 outputs a signal in a first state by comparing the current flowing in the motor unit 600 with the current of the current source IS1 according to the driving start signal, and the current flowing in the motor unit 600 is a current source. The second state signal is output at a time higher than the current of IS1 so that the operation of the mask unit 300 is changed. At this time, it is preferable that the current of the current source IS1 be close to the current generated when the motor is driven normally. This is for the point in time at which the signal in the second state is generated to be the point in time to drive the motor.

The mask unit 300 receives an output of the startup unit 100 and an output of the switch unit 200 and applies an output signal to the rectifier 400, to the driving start signal S1 of the startup unit 100. Accordingly, the masking signal is output to the rectifier 400 and the output of the masking signal is stopped when the signal of the switch unit 200 changes from the first state to the second state. In this case, the masking operation is to reduce the operation enable section of the rectifier 400 to a predetermined range so as to accurately detect the position of the rotor.

The rectifier 400 has an output of the start-up unit 100, an output of the mask unit 300, and an output of the comparator 700, and has seven output stages, and the constant speed rotation is performed from the stop. It runs in three modes until The three modes are the position detection mode for detecting the position of the rotor in the stopped state, the initial driving mode for initial driving to allow the motor to rotate forward in consideration of the detected position of the rotor, and the normal mode for driving the motor at constant speed. to be.

The inverter circuit 500 has a transistor Q1 coupled to a collector voltage Vdc and an emitter connected to a U phase coil U, a collector coupled to the power voltage Vdc, and a V phase coil V. ), A collector is coupled to the transistor Q2 having an emitter coupled thereto, a collector is coupled to the power supply voltage Vdc, and a collector is coupled to the emitter of the transistor Q1, A transistor Q4 connected to an emitter connected to an input terminal of the comparator COM2 and a comparator COM4 below, a collector connected to an emitter of the transistor Q2, and an input terminal of the comparator COM3 and a comparator COM2 A transistor connected to an emitter of transistor Q5, which has an emitter connected to another input terminal of transistor Q3, and a transistor Q6 having an emitter connected to another input terminal of comparator COM2 and another input terminal of comparator COM2, Collector is connected to the neutral point of three-phase coil (U, V, W) and NPN A transistor Q7 having an emitter connected to the emitters of the transistors Q4, Q5, and Q6, and a resistor RS having one end connected to the emitter of the transistor Q7 and the other end connected to the ground terminal.

The comparator 700 compares the currents caused by the magnetic and mutual inductances generated in the respective coils U, V, and W in the position detection mode with respect to the magnitudes of the relative currents flowing through the coils U, V, and W. Outputs the information to the rectifier 400, compares the counter electromotive force generated in each coil (U, V, W) in the initial driving mode and the normal mode with each other and compares the result as the basic information for controlling the inverter circuit (500) To 400).

To this end, the comparator 700 has a non-inverting terminal connected to an inverting terminal of the comparator COM2 and a non-inverting terminal connected to an emitter of the transistor Q1 and an inverting terminal connected to an emitter of the transistor Q3. Is connected and an inverting terminal is connected to the emitter of transistor Q5, and a non-inverting terminal is connected to the inverting terminal of the comparator COM3, and a comparator is connected to the non-inverting terminal of the comparator COM2 ( COM4).

As a result, the comparator COM2 compares the voltage Vu of the U-phase coil U with the voltage Vv of the V-phase coil V to output the first comparison output EUV_COMP, and the comparator COM3 is V. The second comparison output EVW_COMP is output by comparing the voltage Vv of the phase coil V with the voltage Vw of the W phase coil W, and the comparator COM3 outputs the voltage of the W phase coil W ( The third comparison output EWU_COMP is output to the rectifier 400 by comparing Vw and the voltage Vu of the U-phase coil U.

A sensorless BCD motor according to an embodiment of the present invention having the above configuration will become apparent from the following description with reference to the attached FIGS.

First, the operation of the sensorless BCD motor according to the embodiment of the present invention in the position detection mode will be described.

When the driving start signal S1 is output from the startup unit 100 (S100), the rectifier 400 sets the position detection mode (S200) and the transistors Q1 and Q3 as shown in FIGS. 2A and 2B. , Q5 and Q7) output the drive signal. That is, the rectifier 400 outputs a high signal to an output terminal connected to the base of the transistors Q1, Q3, Q5, and Q7 among the seven output terminals, and outputs a low signal through the remaining output terminals.

Then, the transistors Q1, Q3, Q5 and Q7 are turned on and the current applied from the power supply voltage Vcc flows to the ground terminal through each of the phase coils U, V, and W (S300).

Here, each coil (U, V, W) is magnetized by a current applied to the coils (U, V, W) at the same time affects and is affected by the magnetic field of the rotor. Through this principle, the magnetic inductance of the coil appearing on the motor is represented by Equation 2 below.

Where kk = 1, 2, 3, La is the winding inductance [H], Lg is the air gap inductance [H], n is the magnet pole-pair, and Lkk is the magnetic inductance [H].

In addition, the mutual inductance between the coils can be expressed as Equation (3).

Here, Luv and Lvu are mutual inductances between a U-phase coil and a V-phase coil, Luw and Lwu are mutual inductances between a U-phase coil and a W-phase coil, and Lvw and Lwv are mutual inductances between a W-phase coil and a V-phase coil.

As can be seen from Equation 2 and Equation 3, since the inductance of each coil (U, V, W) has a different value depending on the position of the rotor, the current increase rate of each coil (U, V, W) is Different from each other, the current of each of the coil (U, V, W) is increased with different inclination as shown in Fig. 2a and 2b (c).

At this time, the waveform shown in (c) of FIG. 2A shows that the U-phase coil U has the smallest array angle with the magnetic pole of the rotor, and the V-phase coil V has the smallest array angle with the rotor. W phase coil W has the largest array angle with the rotor. On the other hand, the waveform shown in (c) of FIG. 2B is a waveform when the arrangement angle with the rotor is large in the order of the V-phase coil V, the U-phase coil U, and the W-phase coil W. 2A and 2B represent voltages, which are 0V at the to point and become larger toward the right.

These currents having different rates of increase are represented by the voltages Vu, Vv, and Vw at the emitters of the transistors Q1, Q3, and Q5, and are compared with each other by three comparators COM2 to COM4, and the comparison result is determined by the rectifier ( 400).

Here, as shown in Fig. 2A, when the U-phase coil voltage Vu is greatest, the V-phase coil voltage Vv is next, and the W-phase coil voltage Vw is lowest, The comparators COM2 to COM4 generate outputs as shown in FIGS. That is, the comparator COM2 outputs a high signal because the non-inverting input voltage Vu is greater than the inverting input voltage Vv, and the comparator COM3 has a non-inverting voltage Vv greater than the inverting input voltage Vw. A low high signal is output, and the comparator COM4 outputs a low signal because the non-inverting input voltage Vw is smaller than the inverting input voltage Vu.

On the other hand, as shown in Fig. 2B, when the V-phase coil voltage Vv is greatest, the U-phase coil voltage Vu is next, and the W-phase coil voltage Vw is lowest, the voltage is generated. Comparators COM2 output a low signal, comparator COM3 outputs a high signal, and comparator COM4 outputs a low signal as shown in (d) to (b) of 2b.

From the output results of the comparators COM2 to COM4 as shown in FIGS. 2A and 2B (D) to (B), it can be seen that the output of the comparator generates two output results regardless of what value each coil voltage represents. have. That is, the first output result indicates two high signals and one low signal as shown in FIG. 2A, and the second output result indicates two low signals and one high signal as shown in FIG. 2B (S600).

The output results of the comparators COM2 to COM4 serve as inputs of the rectifier 400 to serve as a reference for determining the position of the rotor.

At this time, the sensorless BCD motor according to the embodiment of the present invention, as described above, the output of the comparator (COM2 to COM4) applied to the rectifier 400 to detect the exact position of the rotor switch unit 200 And through the mask unit 300. That is, in the sensorless BCD motor according to the embodiment of the present invention, the position detection operation of the rectifying unit 400 may be started in accordance with an enable signal such as (b) of FIGS. 2A and 2B output from the mask unit 300. As a result, the signals applied from the comparators COM2 to COM4 are ignored before the enable signal of the mask unit 300 (S400).

This operation is apparent from the operation of the switch SW to the output of the mask unit 300.

The switch SW is turned on by receiving the driving start signal S1 from the startup unit 100 at the same time as the rectifier 400 and converts the current applied from the current source IS1 to the voltage V1 by the resistor R. It is applied to the inverting terminal of the comparator COM1. At this time, the voltage V2 output from the current amplifier AMP is applied to the non-inverting terminal of the current comparator COM1.

Here, the voltage V2 applied to the non-inverting terminal of the current comparator COM1 is a voltage corresponding to the current flowing through the three-phase coils U, V, and W. If this is explained in terms of the current flowing through the three-phase coils U, V, and W, the current flowing through the three-phase coils U, V, and W passes through the neutral point of the motor and passes through the transistor Q7 through the resistor RS. Is converted into a voltage and input to the current amplifier AMP. Since the amount of current flowing through the three-phase coils U, V, and W is extremely small, the current amplifier AMP is amplified with a constant gain (K) to obtain a current comparator ( To the non-inverting terminal of COM1).

The sensorless BCD motor according to the embodiment of the present invention sets the voltage V1 applied to the inverting terminal of the current comparator COM1 to a voltage generated when the motor rotates at a constant speed. This is because the output of the current comparator COM1 is applied to the mask part 300 to control the operation of the mask part 300, so that excessive current does not flow to the three-phase coil or the transistors Q1 to Q7 when the motor is driven. .

At this time, setting of the voltage V1 can be facilitated by adjusting the value of the current or the resistance R of the current source IS1. As a result, the output of the current comparator COM1 outputs a low signal in the position detection mode.

The low output of the current comparator COM1 causes the mask unit 300 to perform a masking operation. The masking operation is not to detect the position from the time t0 applied to the start signal S1 as described above with reference to FIGS. 2A and 2B but to start the position detection at the time t2 to the time t3. That is, the interval t0-t2 and the interval t3 or later of the start signal S1 are disabled. In this masking operation, the rectifier 400 detects the position of the rotor by starting the position detection at the point where each coil voltage Vu, Vv, Vw shows a difference, and then finishes the position detection at a point where position detection determination is sufficiently possible. This is done correctly.

Therefore, the rectifier 400 detects the outputs of the comparators COM2 to COM4 during the time t3 from the time t2 shown in FIGS. 2A and 2B by the masking operation of the mask part 300.

The outputs of the comparators COM2 to COM4 thus detected are used by the rectifier 400 to detect the position of the rotor. When the rectifier 400 inputs two high signals and one low signal as shown in FIG. The position of the rotor is determined based on the low signal, and the other two high signals determine which coil has a larger current to detect the correct position of the rotor. When the rectifier 400 inputs two low signals and one high signal as shown in FIG. 2B, the rectifier 400 determines the position of the rotor based on one high signal, and the current of the coil frozen through the remaining two low signals is further increased. Determine whether it is small and detect the exact rotor position.

The rotor position detection criterion of the rectifier 400 is based on FIG. 3, and performs an initial driving mode according to the position detection of the rotor detected based on FIG. 3. In the initial driving mode, the transistor Q7 is turned off, and a current having a 120 ° phase difference is applied to each of the coils U, V, and W, respectively.

FIG. 3 is a switching pattern diagram of an inverter circuit for rotating a sensorless BCD motor in a forward direction according to the magnitude of an inductance proportional to a current according to an embodiment of the present invention. In Fig. 3, ① is an inductance waveform diagram of the U-phase coil U, ② is an inductance waveform diagram of the V-phase coil V, and ③ is an inductance waveform diagram of the W-phase coil W. ④ shows the procedure of driving the transistor of the inverter circuit 500 according to the inductance value of each coil (U, V, W).

Referring to FIG. 3, the rectifier 400 may drive the transistor based on a coil having a relatively large inductance or a relatively small inductance. As a result, the rectifier 400 may recognize the following fact. That is, the rectifier 400 drives the transistor Q1 when the inductance of the U-phase coil U is relatively large, and drives the transistor Q4 when the inductance is relatively small, and the inductance of the V-phase coil V. Is relatively large, it drives transistor Q3, and if inductance is relatively small, it drives transistor Q6. If the inductance to W-phase coil W is relatively large, it drives transistor Q5. (Q2) is driven.

Here, the waveforms of the inductances generated in the coils U, V, and W are the same as 1, 2, and 3 in FIG. 3, as shown in FIG. 4, which simulates the inductances generated in the coils U, V, and W. FIG. have. The inductance waveforms generated in the coils U, V, and W shown in FIG. 4 are the same as the inductance waveforms of FIG.

Accordingly, since the magnitude of the inductance generated in the three-phase coils U, V, and W is proportional to the magnitude of the current, the rectifier 400 generates a signal for driving two transistors according to the output signals of the comparators COM2 to COM4. Output

Through the above, the rectifier 400 can be seen that from the output of the comparators (COM2 to COM4) the rotor to drive a certain transistor (two of the Q1 to Q6) for the forward drive of the motor in response to the position state.

Referring to the case of FIG. 2A as an example, the rectifier 400 detects that the W phase coil voltage Vw is the lowest and the U phase coil voltage Vu is the highest, thereby turning on the transistor Q2. And a signal for turning on the transistor Q1 are output to the inverter circuit 500. Then, the rectifier 400 outputs a signal for turning off the transistor Q1 and turning on the transistor Q3 in the set forward motor driving order, turning off the transistor Q2 and turning the transistor Q4 again. Outputs a signal to turn on. This order follows the arrangement order as shown in Fig. 3.

As described above, when the rectifier 400 detects the position of the rotor and initially drives the motor, currents generated by the counter electromotive force are generated in each of the coils U, V, and W, not by the magnetic and mutual inductances. Therefore, the current of each coil (U, V, W) gradually increases during the initial driving.

As such, when the current of each of the coils U, V, and W increases, the voltage V2 output from the current amplifier AMP increases to exceed the voltage V1 at some point in time. Then, the current comparator COM1 switches its output from a low signal to a high signal so that the startup unit 100 does not output the driving start signal S1 and the mask unit 300 does not perform the masking operation (S700). ).

The operation in the normal mode of such a motor will be apparent in the following description with reference to FIG. FIG. 5 is a timing diagram in which a sensorless BCD motor detects the position of the rotor using a back EMF waveform according to an embodiment of the present invention.

After a predetermined time after the motor starts to drive according to the switching pattern of the rectifier 400, each coil (U, V, W) as shown in equation (1) of Figure 5 (a) to (c) and The counter electromotive force voltage of the same predetermined level or more is generated, and the counter electromotive force voltage is input to the comparators COM2 to COM4. In Fig. 5, (a) is the back EMF voltage EVu generated in the U-phase coil U, (B) is the back EMF voltage EVv generated in the V-phase coil V, and (C) is the W-phase coil W ) Is the back EMF voltage (EVw) generated.

Accordingly, the comparator COM2 compares the counter electromotive force EVu generated in the U-phase coil U with the counter electromotive force voltage EVv generated in the V-phase coil V, and the comparator COM3 is generated in the U-phase coil U. The counter electromotive force EVu is compared with the back electromotive force voltage EVw generated in the W phase coil W. The comparator COM4 compares the back electromotive force EVw generated in the W phase coil W and the back electromotive force voltage generated in the U phase coil U. Compare (EVu).

Comparison results of the comparators COM2 to COM4 are as shown in Figs. Fig. 5D is an output EUV_COMP1 of the comparator COM2, Fig. 5E is an output EVW_COMP2 of the comparator COM3, and Fig. 5B is an output of the comparator COM4. EWU_COMP3).

The comparison outputs of FIGS. 5 (d) to 5 (a) are applied to the rectifier 400, and the rectifier 400 uses waveforms of the comparators outputs EUV_COMP1, EVW_COMP2, and EWU_COMP3 as motor control signals. That is, the rectifier 400 is configured to drive the transistors Q1 and Q6 corresponding to the comparator outputs EUV_COMP1, EVW_COMP2, and EWU_COMP3. The transistor is turned on or off to control the direction of the current applied to each of the coils U, V, and W (S800).

Therefore, the motor rotates at a constant speed in the forward direction by the operation of the rectifier 400 using the recognition signals EU, EV, and EW.

From the above description, it can be seen that the sensorless BLD motor according to the embodiment of the present invention achieves the object of the present invention according to the first and second features. 6 and 7 further clarify the features of the present invention to achieve the object using inductance. FIG. 6 is a first simulation diagram for detecting the rotor position of a sensorless non-ELD motor according to an embodiment of the present invention, and FIG. 7 is a detecting part of the rotor of a sensorless non-ELD motor according to an embodiment of the present invention. It is a 2nd simulation drawing for this.

In Fig. 6, (a) to (c) are the outputs of the comparators COM2 to COM4, and (d) represents the voltage generated in each coil. In Fig. 6, the U phase coil voltage Vu shown by the solid line is the largest, the V phase coil voltage Vv shown by the dotted line is the next, and the W phase coil voltage Vw shown by the center line is the most. It can be seen that it is small, and accordingly, the outputs of the comparators COM2 to COM4 output high, high, and low signals.

FIG. 7 shows the coil voltages Vu, Vv, Vw and the outputs of the comparators COM2 to COM4 detected in a state different from that of FIG. 6, that is, when the position of the rotor is not the same as that of FIG. EWU_COM), when the simulation time is larger than that in FIG. In Fig. 7, it can be seen that the detecting operation of the position of the rotor is repeated several times, which is to detect the position of the rotor more accurately. 7 shows that the W phase coil voltage Vw shown by the center line is the largest, the U phase coil voltage Vu shown by the solid line is the next, and the V phase coil voltage Vv shown by the dotted line is the smallest. Accordingly, it can be seen that the outputs of the comparators COM2 to COM4 output high, low, and high signals.

Although this invention has been described with reference to the most practical and preferred embodiments, the invention is not limited to the embodiments disclosed above, but also includes various modifications and equivalents which fall within the scope of the following claims.

The present invention has the effect of reducing the cost of the product and preventing the motor from rotating in the initial operation by detecting the position of the rotor to drive the motor without using the sensor in the state in which the motor is stopped.

Claims (15)

(Correction) a motor unit including a rotor having a magnetic pole arranged in sequence and a stator consisting of a three-phase coil; A startup unit for applying a driving start signal for a predetermined time; A comparator comprising first, second and third comparators for comparing inductance currents flowing in each phase of the three-phase coil with each other and comparing back electromotive force voltages flowing in each phase of the three-phase coil with each other and outputting a comparison result ; Driving according to a driving start signal of the startup unit, detecting position detection and motor control information of the rotor according to an output of the comparison unit, and applying a current applied to the motor unit to a first control mode, a second control mode, and Control according to a third control mode, wherein the first control mode is a position detection mode for simultaneously applying current to each coil for a predetermined time to detect the position of the rotor, and the second control mode is An initial driving mode for driving the motor unit in consideration of a position, and the third control mode includes a rectifying unit which is a normal mode for controlling the motor unit to perform constant speed rotation; An inverter circuit for changing a current direction applied to the three-phase coil according to different switching signals applied by the first, second, and third control modes of the rectifier; A switch unit which turns on according to a driving start signal of the startup unit and outputs a first signal, and when the counter electromotive force generated in the motor unit is higher than a predetermined level, the switch unit turns off and outputs a second signal; And While the rectifier drives in the position detection mode, a masking signal for narrowing the operation enable section of the rectifier to a predetermined section is output to the rectifier, and the masking signal is not output during the initial driving mode and the normal mode. Sensorless Bieldich motor comprising a mask portion . (delete) The method of claim 1 , The switch unit, A first comparator having two input terminals and an output terminal, the first comparator outputting the first or second signal to the start-up unit according to the input voltage, and the comparator based on the driving start signal of the start-up unit; And a reference voltage section for applying a predetermined level of voltage, and a current amplifier for converting a current flowing in a three-phase coil applied from the inverter circuit into a voltage and applying the voltage to an input terminal of the first comparator. The method of claim 3, The switch unit, A reference voltage part comprising a switch connected to a current voltage coupled to a reference voltage by a driving start signal of the startup part, and having one end connected to the current source and a first resistor connected at one end of the switch and grounded at the other end of the switch; A current amplifier having a first input coupled to a neutral point of the motor and a second input connected to a ground terminal to amplify the input current by a set gain, and a non-inverting terminal connected to the contact of the switch and the first resistor and the current And a first comparator including an inverting terminal connected to an output terminal of the amplifier and an output terminal coupled to an input terminal of the rectifying unit to output a first signal in a low state or a second signal in a high state. (delete) The method of claim 1 , The mask unit, An output terminal is connected to an output terminal of the switch unit and the startup unit, and an output terminal is connected to an input terminal of the rectifying unit, and outputs a masking signal according to the first signal of the switch unit, and does not output a masking signal according to the second signal of the switch unit. Sensorless Bieldi motor. The method of claim 1, The rectifying unit, The position detection mode is set according to the driving start signal output from the start-up unit, the initial driving mode is set at the position detection time of the rotor detected according to the output signal of the comparator, and the counter electromotive force of a certain level is generated. Sensorless Bieldish motor characterized by setting the normal mode from the point of time. The method of claim 1, The inverter circuit, A first NPN transistor having a collector coupled to a power supply voltage and an emitter coupled to a U-phase coil, a second NPN transistor having a collector coupled to the power supply voltage and an emitter coupled to a V-phase coil, a collector coupled to the power supply voltage A third NPN transistor having a ring connected to an emitter connected to a W-phase coil, a fourth NPN transistor having a collector connected to an emitter of the first NPN transistor, and an emitter connected to an input terminal of the first comparator and the third comparator, A collector connected to an emitter of a second NPN transistor and an emitter connected to an input terminal of the second comparator and another input terminal of the first comparator, and a collector connected to an emitter of the third NPN transistor; A sixth NPN transistor having an emitter connected to the other input terminal of the second comparator and the other input terminal of the third comparator, the neutral point of the three-phase coil, and the fourth, And a path control means positioned between the fifth and sixth NPN transistors so that current is applied to all of the three-phase coils. The method of claim 8, The path control means, A seventh NPN transistor having a collector connected to a neutral point of the three-phase coil and an emitter connected to an emitter of the fourth, fifth and sixth NPN transistors, and the fourth, fifth, sixth and seventh NPN transistors Sensorless Bieldi motor, characterized in that the second end is connected to the emitter of the second end connected to the ground terminal. The method of claim 1, The comparison unit, A non-inverting terminal is connected to the emitter of the fourth NPN transistor, an inverting terminal is connected to the emitter of the fifth NPN transistor, and a non-inverting terminal is connected to the inverting terminal of the second comparator. And a third comparator having an inverting terminal connected to the emitter of the second comparator, and a fourth comparator having a non-inverting terminal connected to the inverting terminal of the third comparator and a inverting terminal connected to the non-inverting terminal of the second comparator. Bieldi Motors. (Correction) consisting of a first switch group consisting of a plurality of switches coupled between a power supply voltage and each of the three-phase coils U, V, and W of the motor, and a plurality of switches coupled between the motor and ground, respectively An inverter having a third switch group connected between a second switch group and a neutral point of the motor and a ground terminal, a rectifier controlling on / off of each switch of the inverter, and a comparison unit comparing the coil voltages. In the control method of the motor control circuit, A first step of generating mutual inductance between each coil and the rotor by simultaneously applying current to all three-phase coils according to a driving start signal generated for a predetermined time; A second step of detecting a position of the rotor by comparing currents flowing in the three-phase coils according to mutual inductances generated in the first step; A third step of driving the motor to a constant speed in consideration of the position of the rotor obtained in the second step; A fourth step of controlling the direction of the current applied to the three-phase coil as a counter electromotive force of the motor rotating at a constant speed to operate the motor at a constant speed; And And a fifth step of limiting an operation enable period of the rectifier until the current flowing through the three-phase coil is greater than or equal to a predetermined value so that excessive current does not flow in the three-phase coil and facilitates the position detection of the rotor. How to drive a sensorless Bieldic motor (delete) The method of claim 11, And said first step turns on all switches of said first switch group and turns on all switches of said third switch group. The method of claim 13, The second step includes comparing the voltage of the U-phase coil and the voltage of the V-phase coil, comparing the V-phase coil voltage and the W-phase coil voltage, and comparing the W-phase coil voltage and the U-phase coil voltage. Sensorless Bieldi motor drive method characterized by. The method of claim 14, In the third step, since the rectifying unit stores information that the voltage magnitude sequence between the coils must be driven from one of the transistors of the inverter, information about the voltage magnitude order of each coil obtained by the second step is stored. A method of driving a sensorless Bildish motor, characterized in that selectively driving a transistor of the inverter.