TWI431926B - Three-phase motor circuit structure and control method thereof - Google Patents

Description

Three-phase motor circuit structure and control method thereof

The invention relates to a three-phase motor circuit structure and a control method thereof, in particular to a 180-degree commutation control method applied to a Y/triangular line-varying three-phase motor.

Referring to FIG. 1 , a circuit structure of a conventional variable structure motor is shown, and in the circuit structure of the conventional variable structure motor, a U-phase winding module 91 and a V-phase winding are included. The module 92, a W-phase winding module 93, a three-phase full-bridge converter 94, a first sensing module 95, a second sensing module 96, and a control unit 97. Each of the U-phase winding module 91, the V-phase winding module 92 and the W-phase winding module 93 has a first switch, a phase coil and a second switch serially connected in series, and is switched by For the opening and closing of the first and second switches, the three phase coils of the U-phase winding module 91, the V-phase winding module 92 and the W-phase winding module 93 can be connected to form a Y-junction winding or a The winding type of the triangulation winding. The three-phase full-bridge converter 94 has three driving arms each formed by a series of two switches, which are respectively a U-phase arm 941, a V-phase arm 942 and a W-phase arm 943, and the U-phase arm 941 The midpoint of the second switch is connected to the U-phase winding module 91, and the midpoint of the two switches of the V-phase arm 942 is connected to the V-phase winding module 92, and the W-phase arm 943 The midpoint of the series connection of the two switches is connected to the W-phase winding module 93. The first and second sensing modules 95, 96 are disposed adjacent to the rotor R of the conventional variable structure motor for generating a set of position sensing signals corresponding to the positions of the rotor R, respectively. The control unit 97 is electrically connected to the first and second sensing modules 95 and 96 to receive the position sensing signals respectively generated by the two sensing modules 95 and 96, and the control unit 97 is also electrically connected. The switch of each of the driving arms of the three-phase full-bridge converter 94 is configured to sense the signal according to the position sensed by the first sensing module 95 or the position sensing signal output by the second sensing module 96. After generating a set of driving signals, the driving signals of the driving arms of the three-phase full-bridge converter 94 are controlled by the driving signals to drive the conventional variable structure motor. In addition, the control unit 97 is also connected to the first switch and the second switch of the U-phase winding module 91, the V-phase winding module 92 and the W-phase winding module 93 to control all the windings. The winding patterns of the phase coils of the modules 91, 92, 93 are combined.

When the above-mentioned conventional variable structure motor is operated, the control unit 97 first controls all the first switches and the second switches of the winding modules 91, 92, 93 so that the three phase coils form the Y junction line. Winding, at this time, the Y-junction winding has a higher torque constant characteristic; then, when the variable structure motor speed increases and enters a high speed state, the control unit 97 controls each of the first switch and the second switch to The three phase coils constitute the triangular junction winding, thereby increasing the maximum rotational speed by utilizing the characteristic that the triangular junction winding has a small back electromotive force constant. Wherein, when the control unit 97 generates the driving signal to control the three phase coils of the Y-junction winding or the triangular junction winding, the 120-degree driving method of the Y-junction is highly compatible with the triangular-degree 120-degree driving method. Generally, the control unit 97 operates the Y-junction winding by a Y-junction 120-degree driving method, and operates the triangular-coupling winding by a triangulation 120-degree driving method, so that the conventional variable structure motor can be between the two winding types. Switching smoothly. However, since the commutation point of the two driving methods has an electrical angle difference of 30 degrees, the rotor position of the first sensing module 95 when the Y-junction winding is driven is required to be set, and the rotor position must be changed. The second sensing module 96 is provided to sense the rotor position when the triangular wire winding is driven.

On the other hand, if the driving method of the variable structure motor is changed, the triangular junction winding is operated by a triangular junction 180 degree driving method instead of the triangular junction 120 degree driving method, although the triangular junction 180 degree driving method and the Y junction line can be used. The advantage of no electrical angular difference between the 120 degree driving methods omits the setting of the second sensing module 96. However, due to the conventional triangular junction 180 degree driving method, the phase coil without the control current will be converted into a generating coil. The brake is braked on the rotor, which causes the variable structure motor to have disadvantages such as uneven output and unstable rotational speed.

Based on the above reasons, it is necessary to further improve the circuit structure of the above-described variable structure motor and its control method, in order to simplify the structural complexity and simultaneously improve the rotational stability of the variable structure motor.

The object of the present invention is to provide a method for controlling a three-phase motor, so that a phase coil having no input current in a three-phase motor having a triangular junction line is formed in an open state to achieve a stable output and a rotational speed.

The object of the present invention is to provide a three-phase motor circuit structure and a control method thereof, which only need to use a group of Hall elements when used in a Y/triangular line-varying three-phase motor, thereby achieving the purpose of reducing manufacturing cost and assembly complexity.

The technical means of the present invention is: a method for controlling a three-phase motor, comprising: controlling three arms of a three-phase full-bridge converter to generate three phase currents respectively connected to three-phase motors with triangular junction lines a node, wherein each of the upper arm switch and the lower arm switch has a continuous 180 degree angular range in each rotation period of the three-phase motor, and a phase difference between the two phase currents Is 120 degrees; and disconnecting a switch of the three-phase motor, wherein the open relationship is in series with a phase coil of the three-phase motor between two nodes of the three nodes, and is connected to the two nodes The current direction of the two-phase current is the coil group flowing into or out of the stator of the three-phase motor.

The control method of the three-phase motor further includes: the three arm systems are a U-phase arm, a V-phase arm and a W-phase arm, and the three phase current systems correspond to a U-phase current, a V-phase current, and a W phase current, and during each rotation period of the three-phase motor, a program for controlling the three arms to generate the three phase currents respectively to the three nodes includes: a first step, The U-phase arm and the W-phase arm upper arm switch and the V-phase arm lower arm switch are turned on, and the U-phase arm and the W-phase arm lower arm switch and the V-phase arm upper arm switch are both turned off; In the second step, after completing the first step, the U-phase arm upper arm switch and the V-phase arm and the W-phase arm lower arm switch are turned on, and the U-phase arm lower arm switch and the V-phase arm and W The upper arm switch of the phase arm is in an open state; in a third step, after completing the second step, the U-phase arm and the V-phase arm upper arm switch and the W-phase arm lower arm switch are turned on, and the U The phase arm and the V-phase arm lower arm switch and the W-phase arm upper arm switch are both in an open state; a fourth step, after completing the third step, the V-phase arm is above The arm switch and the U-phase arm and the W-phase arm lower arm switch are turned on, and the V-phase arm lower arm switch and the U-phase arm and the W-phase arm upper arm switch are both in an off state; a fifth step, After the fourth step is completed, the V-phase arm and the W-phase arm upper arm switch and the U-phase arm lower arm switch are turned on, and the V-phase arm and the W-phase arm lower arm switch and the U-phase arm upper arm The switch is in an open state; and a sixth step, after completing the fifth step, turning on the W-phase arm upper arm switch and the U-phase arm and the V-phase arm lower arm switch, and the W-phase arm The lower arm switch and the U-phase arm and the V-phase arm upper arm switch are all in an open state.

The control method of the three-phase motor further includes: a program for disconnecting the switch of the three-phase motor is: in the first step, a one of the two nodes connected in series between the U-phase arm and the W-phase arm a first W-phase switch as the switch, and disconnecting the first W-phase switch, wherein the first W-phase open relationship is in series with the U-phase coil of the three-phase motor; in the second step, in series a first V-phase switch between the two nodes of the V-phase arm and the W-phase arm as the switch, and disconnecting the first V-phase switch, wherein the first V-phase open relationship and the three-phase motor The W-phase coil is connected in series; in the third step, a first U-phase switch connected between the two nodes of the U-phase arm and the V-phase arm is used as the switch, and the first is disconnected a U-phase switch, wherein the first U-phase open relationship is connected in series with the V-phase coil of the three-phase motor; in the fourth step, the first W-phase switch is used as the switch, and the first W is disconnected a phase switch; in the fifth step, the first V-phase switch is used as the switch, and the first V-phase switch is turned off; and in the sixth step, the first U-phase switch is used as the switch, The first U-phase disconnect switches.

The technical means of the present invention further comprises: a circuit structure of a three-phase motor, comprising a U-phase winding module, a V-phase winding module, a W-phase winding module, a three-phase full-bridge converter, A sensing module and a control unit. The U-phase winding module has a first U-phase switch, a U-phase coil and a second U-phase switch serially connected in series, and a U-phase node is arranged between the first U-phase switch and the U-phase coil A U-phase change structure contact is disposed between the U-phase coil and the second U-phase switch. The V-phase winding module has a first V-phase switch, a V-phase coil and a second V-phase switch serially connected in series, and a V-phase node is arranged between the first V-phase switch and the V-phase coil A V-phase change structure contact is disposed between the V-phase coil and the second V-phase switch. The W-phase winding module has a first W-phase switch, a W-phase coil and a second W-phase switch serially connected in series, and a W-phase node is arranged between the first W-phase switch and the W-phase coil A W phase change structure contact is disposed between the W phase coil and the second W phase switch. The three-phase full-bridge converter has a U-phase arm, a V-phase arm and a W-phase arm, each of the arms having an upper arm switch and a lower arm switch connected in series with each other, and a form is formed between the upper arm switch and the lower arm switch a series connection point, wherein the U-phase arm series connection point is connected to the U-phase node, the V-phase arm series connection point is connected to the V-phase node, and the W-phase arm connection point is connected to the W-phase node. The sensing module has only three rotor position sensing elements for generating a set of position sensing signals according to the position of a rotor R. The control unit is electrically connected to the first U-phase switch and the second U-phase switch of the U-phase winding module, the first V-phase switch and the second V-phase switch of the V-phase winding module, and the W phase Controlling the first W-phase switch and the second W-phase switch of the winding module, the upper arm switch and the lower arm switch of the three-phase full-bridge converter, and each of the rotor position sensing elements of the sensing module to control The U-, V-, and W-phase coils exhibit a winding type, and output a set of driving signals to the three-phase full-bridge converter according to the position sensing signal. The U-phase change structure is coupled to the first W-phase switch and is not connected to one end of the W-phase node. The V-phase change structure contact is coupled to the first U-phase switch and is not connected to one end of the U-phase node. The W phase change structure contact is coupled to the first V phase switch not connected to one end of the V phase node, and the second U phase, V phase and W phase switch are not connected to the U phase, V phase or W phase coil One end is connected to each other.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Please refer to FIG. 2, which illustrates a variable structure three-phase motor circuit structure according to a preferred embodiment of the present invention, wherein the circuit structure includes a U-phase winding module 1 and a V-phase winding module 2. A W-phase winding module 3, a three-phase full-bridge converter 4, a sensing module 5 and a control unit 6. Wherein, the U-phase winding module 1, the V-phase winding module 2 and the W-phase winding module 3 are connected to each other to form a coil group of a stator of a variable-structure three-phase motor; the three-phase full-bridge converter 4 electrically connecting the power source E and the U, V and W phase winding modules 1, 2, 3 to supply power to the U, V and W phase winding modules 1, 2, 3; The module 5 is disposed adjacent to the rotor R of the variable structure three-phase motor; the control unit 6 is electrically connected to the U, V and W phase winding modules 1, 2, 3, the three-phase full bridge converter 4 and sensing Module 5 to control each of the above components.

In detail, the U-phase winding module 1 has a first U-phase switch 11 , a U-phase coil 12 and a second U-phase switch 13 connected in series, the first U-phase switch 11 and the U A U-phase node 14 is disposed between the phase coils 12, and a U-phase change structure contact 15 is disposed between the U-phase coil 12 and the second U-phase switch 13. The V-phase winding module 2 has a first V-phase switch 21, a V-phase coil 22 and a second V-phase switch 23 connected in series, and the first V-phase switch 21 and the V-phase coil 22 A V-phase node 24 is disposed therebetween, and a V-phase change structure contact 25 is disposed between the V-phase coil 22 and the second V-phase switch 23. The W-phase winding module 3 has a first W-phase switch 31, a W-phase coil 32 and a second W-phase switch 33 connected in series, and the first W-phase switch 31 and the W-phase coil 32 A W-phase node 34 is disposed therebetween, and a W-phase-change structure contact 35 is disposed between the W-phase coil 32 and the second W-phase switch 33. The end of the second U-phase switch 13 that is not connected to the U-phase coil 12, the end of the second V-phase switch 23 that is not connected to the V-phase coil 22, and the second W-phase switch 33 are not associated with the W phase. One end of the connection of the coils 32 is connected to each other. In addition, the U-phase change structure contact 15 is coupled to the first W-phase switch 31 and is not connected to one end of the W-phase node 34. The V-phase change structure contact 25 is coupled to the first U-phase switch 11 and is not connected to the U. One end of the phase node 14 and the W phase change structure contact 35 are coupled to the first V-phase switch 21 and not connected to one end of the V-phase node 24. With the above electrical connection structure, when the first U-phase switch 11, the first V-phase switch 21 and the first W-phase switch 31 are both turned off, the second U-phase switch 13 and the second V-phase switch When the second W-phase switch 33 and the second W-phase switch 33 are turned on, the U, V, and W-phase coils 12, 22, and 32 exhibit a winding type of a Y-junction winding; otherwise, when the first U-phase switch 11 is first The V-phase switch 21 and the first W-phase switch 31 are both turned on, and when the second U-phase switch 13, the second V-phase switch 23, and the second W-phase switch 33 are turned off, the U, V, and W phases The coils 12, 22, 32 present a winding pattern of a triangular wire winding.

Referring again to FIG. 2, the three-phase full-bridge converter 4 has a U-phase arm 41, a V-phase arm 42, and a W-phase arm 43. The U-phase arm 41 has an upper arm switch 411 and a lower arm switch 412 connected in series, and a series of contacts 413 are electrically connected between the upper arm switch 411 and the lower arm switch 412 to electrically connect the U-phase winding module 1 The U-phase node 14 has an upper arm switch 421 and a lower arm switch 422 connected in series with each other, and a series of contacts 423 are electrically connected between the upper arm switch 421 and the lower arm switch 422 to electrically connect the V-phase. The V-phase node 24 of the line module 2 has an upper arm switch 431 and a lower arm switch 432 connected in series with each other, and a series of contacts 433 are formed between the upper arm switch 431 and the lower arm switch 432. The W-phase node 34 of the W-phase winding module 3 is connected. The two ends of the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 are connected to the DC power source E to receive the DC power generated by the DC power source E.

The sensing module 5 is disposed adjacent to the rotor R of the variable structure three-phase motor, and has only three rotor position sensing elements respectively corresponding to the U, V and W phases, so that each rotor position sensing element is A position sensing signal can be generated according to the position of the rotor R. In addition, each of the rotor position sensing elements is preferably a Hall sensor.

The control unit 6 is electrically connected to the first U-phase switch 11 and the second U-phase switch 13 of the U-phase winding module 1, the first V-phase switch 21 and the second of the V-phase winding module 2, respectively. The V-phase switch 23, the first W-phase switch 31 and the second W-phase switch 33 of the W-phase winding module 3, and the upper arm switches 411, 421, 431 and the lower arm switch 412 of the three-phase full-bridge converter 4 422, 432 and the sensing module 5. The control unit 6 can control the upper arm switches 411, 421, 431 and the lower arm switches 412, 422, 432 of the three-phase full-bridge converter 4 according to the position sensing signals output by the sensing module 5. In order to control the current flowing through each of the U-phase, V-phase and W-phase coils 12, 22, 32. At the same time, the control unit 6 further detects the rotation speed of the rotor R according to the position sensing signal, thereby controlling the first U-phase switch 11, the first V-phase switch 21, the first W-phase switch 31, and the second U-phase. The switch 13, the second V-phase switch 23, and the second W-phase switch 33 are turned on or off to determine the winding type exhibited by the U, V, and W-phase coils 12, 22, 32.

With respect to the above-described variable structure three-phase motor circuit configuration of the present invention, the operation control can be performed by the three-phase motor control method of the present invention described below. When the U, V and W phase coils 12, 22, 32 described above exhibit the winding form of the Y junction winding, they can be controlled by the conventional Y junction 120 degree driving method; however, when the U, V and W phase coils are used When 12, 22, and 32 present the winding form of the triangular wire winding, the operation control of the variable structure three-phase motor is performed by the following control method.

First, the control unit 6 controls the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 of the three-phase full-bridge converter 4 to generate a U-phase current iu to the U-phase node 14, a V. The phase current iv is conducted to the V-phase node 24 and a W-phase current iw is coupled to the W-phase node 34. As shown in FIG. 3, in any of the 360-degree rotation periods of the variable-structure three-phase motor of the present invention, each of the upper arm switches 411, 421, and 431 (i.e., U _T , V _T shown in FIG. 3) And W _T ] and the lower arm switches 412, 422, and 432 [i.e., U _B , V _{B ,} and W _B shown in FIG. 3 ] have a continuous range of angles of 180 degrees (that is, a so-called 180 degree driving mode) ], and the phase difference of any of the three phase currents iu, iv, iw is 120 degrees. In detail, as shown in Figures 4a to 4f, in each rotation cycle of the variable structure three-phase motor of the present invention, the program for controlling the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 includes the following The six steps described.

Referring to FIG. 4a, the first step of controlling the U-phase arm 41, the V-phase arm 42, and the W-phase arm 43 is: the U-phase arm 41 and the W-phase arm 43 upper arm switches 411, 431 and the V The lower arm switch 422 of the phase arm 42 is turned on, and the lower arm switches 412 and 432 of the U phase arm 41 and the W phase arm 43 and the upper arm switch 421 of the V phase arm 42 are both turned off. Thereby, the U-phase current iu flows from the upper arm switch 411 to the lower arm switch 422 via the first U-phase switch 11 and the V-phase coil 22; the V-phase current iv is zero; and the W-phase current iw is The upper arm switch 431 flows to the lower arm switch 422 via the W-phase coil 32 and the first V-phase switch 21.

Referring to FIG. 4b, the second step of controlling the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 is: after completing the first step, the U-phase arm 41 upper arm switch 411 and the The V-phase arm 42 and the W-phase arm 43 lower arm switches 422, 432 are turned on, and the U-phase arm 41 lower arm switch 412 and the V-phase arm 42 and the W-phase arm 43 upper arm switches 421, 431 are disconnected. status. Thereby, the U-phase current iu is in a shunt state, wherein a current flows from the upper arm switch 411 to the lower arm switch 422 via the first U-phase switch 11 and the V-phase coil 22, and another current is from the U-phase The coil 12 and the first W-phase switch 31 are circulated to the lower arm switch 432; and the V-phase current iv and the W-phase current iw are both zero.

Referring to FIG. 4c, the third step of controlling the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 is as follows: after completing the second step, The U-phase arm 41 and the V-phase arm 42 upper arm switches 411 and 421 and the W-phase arm 43 lower arm switch 432 are turned on, and the U-phase arm 41 and the V-phase arm 42 lower arm switches 412 and 422 and the W The upper arm switch 431 of the phase arm 43 is in an open state. Thereby, the U-phase current iu flows from the upper arm switch 411 to the lower arm switch 432 via the U-phase coil 12 and the first W-phase switch 31; the V-phase current iv is passed by the upper arm switch 421 via the first V The phase switch 21 and the W-phase coil 32 flow to the lower arm switch 432; and the W-phase current iw is zero.

Referring to FIG. 4d, the fourth step of controlling the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 is: after completing the third step, the V-phase arm 42 upper arm switch 421 and the The U-phase arm 41 and the W-phase arm 43 lower arm switches 412, 432 are turned on, and the V-phase arm 42 lower arm switch 422 and the U-phase arm 41 and the W-phase arm 43 upper arm switches 411, 431 are disconnected. status. Thereby, the V-phase current iv is in a shunt state, wherein a current is flowed by the upper arm switch 421 to the lower arm switch 412 via the V-phase coil 22 and the first U-phase switch 11, and the other current is first The V-phase switch 21 and the W-phase coil 32 are circulated to the lower arm switch 432; and the U-phase current iu and the W-phase current iw are both zero.

Referring to FIG. 4e, the fifth step of controlling the U-phase arm 41, the V-phase arm 42 and the W-phase arm 43 is: after completing the fourth step, the V-phase arm 42 and the W-phase arm 43 are The upper arm switches 421 and 431 and the lower arm switch 412 of the U phase arm 41 are turned on, and the V phase arm 42 and the W phase arm 43 lower arm switches 422 and 432 and the U phase arm 41 upper arm switch 411 are disconnected. status. Thereby, the U-phase current iu is zero; the V-phase current iv is passed by the upper arm switch 421 via the V-phase coil 22 and the first U-phase The switch 11 flows to the lower arm switch 412; and the W-phase current iw flows from the upper arm switch 431 to the lower arm switch 412 via the first W-phase switch 31 and the U-phase coil 12.

Referring to FIG. 4f, the sixth step of controlling the U-phase arm 41, the V-phase arm 42, and the W-phase arm 43 is: after completing the fifth step, the W-phase arm 43 upper arm switch 431 and the The U-phase arm 41 and the V-phase arm 42 lower arm switches 412, 422 are turned on, and the W-phase arm 43 lower arm switch 432 and the U-phase arm 41 and the V-phase arm 42 upper arm switches 411, 421 are disconnected. status. Thereby, the W-phase current iw is in a shunt state, wherein a current is transmitted from the upper arm switch 431 to the lower arm switch 412 via the first W-phase switch 31 and the U-phase coil 12, and another current is generated by the W-phase The coil 32 and the first V-phase switch 21 are circulated to the lower arm switch 422; and the U-phase current iu and the V-phase current iv are both zero.

In addition, in the above six steps, in order to prevent the phase coil that does not have current from passing through the magnetic field of the rotor R in the inductive rotation, an induced current is generated (when the induced current is generated, the rotor R will decelerate due to braking, The control method of the present invention further disconnects a switch of the variable structure three-phase motor of the present invention, and the open relationship is the first U-phase switch 11 and the first V-phase switch. 21 and one of the first W-phase switches 31. The disconnected open relationship and one of the U-phase coil 12, the V-phase coil 22 and the W-phase coil 32 of the variable-structure three-phase motor are connected in series to the U-phase node 14, the V-phase node 24, and the W-phase node. Between the two, and the current direction of the phase currents connected to the U-phase node 14, the V-phase node 24, and the W-phase node 34 is the same as the inflow or outflow of the variable-structure three-phase horse. The coil set of the stator.

In detail, the program for disconnecting the first U-phase switch 11, the first V-phase switch 21 or the first W-phase switch 31 of the three-phase motor is: in the first step, disconnecting the first W a phase switch 31, wherein the first W-phase switch 31 is located between the U-phase node 14 and the W-phase node 34 and is connected in series with the U-phase coil 12; in the second step, the first V-phase switch is turned off 21, wherein the first V-phase switch 21 is located between the V-phase node 24 and the W-phase node 34 and is connected in series with the W-phase coil 32; in the third step, the first U-phase switch 11 is turned off, The first U-phase switch 11 is located between the U-phase node 14 and the V-phase node 24 and is connected in series with the V-phase coil 22; in the fourth step, the first W-phase switch 31 is turned off; In the fifth step, the first V-phase switch 21 is turned off; and in the sixth step, the first U-phase switch 11 is turned off. Therefore, by disconnecting the first V-phase switch 21 or the first W-phase switch 31 of the first U-phase switch 11, the formation of the U-phase coil 12, the V-phase coil 22 or the W-phase coil 32 without excitation is completely avoided. The current loop can reliably overcome the disadvantages of uneven output and unstable speed caused by the induced rotor of the rotor R.

While the present invention has been disclosed in its preferred embodiments, it is not intended to limit the scope of the present invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

[this invention]

1. . . U-phase winding module

11. . . First U phase switch

12. . . U phase coil

13. . . Second U phase switch

14. . . U phase node

15. . . U phase change structure contact

2. . . V-phase winding module

twenty one. . . First V phase switch

twenty two. . . V-phase coil

twenty three. . . Second V phase switch

twenty four. . . V phase node

25. . . V phase change structure contact

3. . . W phase winding module

31. . . First W phase switch

32. . . W phase coil

33. . . Second W phase switch

34. . . W phase node

35. . . W phase change structure contact

4. . . Three-phase full bridge converter

41. . . U-phase arm

411. . . Upper arm switch

412. . . Lower arm switch

413. . . Threading point

42. . . V-phase arm

421. . . Upper arm switch

422. . . Lower arm switch

423. . . Threading point

43. . . W phase arm

431. . . Upper arm switch

432. . . Lower arm switch

433. . . Threading point

5. . . Sensing module

6. . . control unit

E. . . DC power source

R. . . Rotor

[Prior technology]

91. . . U-phase winding module

92. . . V-phase winding module

93. . . W phase winding module

94. . . Three-phase full bridge converter

941. . . U-phase arm

942. . . V-phase arm

943. . . W phase arm

95. . . First sensing module

96. . . Second sensing module

97. . . control unit

Figure 1: Circuit diagram of a conventional variable structure motor.

Fig. 2 is a circuit diagram showing the structure of a three-phase motor in accordance with a preferred embodiment of the present invention.

Fig. 3 is a diagram showing switching waveforms of a U-phase arm, a V-phase arm, and an upper arm switch and a lower arm switch of a three-phase full-bridge converter of a three-phase motor according to a preferred embodiment of the present invention.

Figure 4a is a schematic diagram of the current of the first step of the three-phase motor in the form of a triangular junction winding in accordance with a preferred embodiment of the present invention.

Figure 4b is a schematic diagram of the current of the second step of the three-phase motor in the form of a triangular junction winding in accordance with a preferred embodiment of the present invention.

Figure 4c is a schematic diagram of the current of the third step of the three-phase motor in the form of a triangular junction winding in accordance with a preferred embodiment of the present invention.

Figure 4d is a diagram showing the current of the fourth step of the three-phase motor in the form of a triangular junction winding according to a preferred embodiment of the present invention.

Figure 4e is a diagram showing the current of the fifth step of the three-phase motor in the form of a triangular junction winding according to a preferred embodiment of the present invention.

Figure 4f is a diagram showing the current of the sixth step of the three-phase motor in the form of a triangular junction winding in accordance with a preferred embodiment of the present invention.

1. . . U-phase winding module

11. . . First U phase switch

12. . . U phase coil

13. . . Second U phase switch

14. . . U phase node

15. . . U phase change structure contact

2. . . V-phase winding module

twenty one. . . First V phase switch

twenty two. . . V-phase coil

twenty three. . . Second V phase switch

twenty four. . . V phase node

25. . . V phase change structure contact

3. . . W phase winding module

31. . . First W phase switch

32. . . W phase coil

33. . . Second W phase switch

34. . . W phase node

35. . . W phase change structure contact

4. . . Three-phase full bridge converter

41. . . U-phase arm

411. . . Upper arm switch

412. . . Lower arm switch

413. . . Threading point

42. . . V-phase arm

421. . . Upper arm switch

422. . . Lower arm switch

423. . . Threading point

43. . . W phase arm

431. . . Upper arm switch

432. . . Lower arm switch

433. . . Threading point

5. . . Sensing module

6. . . control unit

E. . . DC power source

R. . . Rotor

Claims (4)

A method for controlling a three-phase motor, comprising: controlling three arms of a three-phase full-bridge converter to generate three phase currents respectively connected to three nodes of a three-phase motor having a triangular junction, wherein each arm The upper arm switch and the lower arm switch have a continuous 180 degree angular range in each rotation period of the three-phase motor, and any phase difference between the phase currents is 120 degrees; and disconnection a switch of the three-phase motor, wherein the open relationship is in series with a phase coil of the three-phase motor between two nodes of the three nodes, and the current of the two-phase current is connected to the two nodes The direction is the coil set that flows into or out of the stator of the three-phase motor. According to the control method of the three-phase motor according to the first aspect of the patent application, wherein the three arm systems are a U-phase arm, a V-phase arm and a W-phase arm, and the three phase current systems correspond to a U-phase. a current, a V-phase current, and a W-phase current, and during each rotation period of the three-phase motor, controlling the three arms to generate the three phase currents respectively connected to the three nodes includes a first step, the U-phase arm and the W-phase arm upper arm switch and the V-phase arm lower arm switch are turned on, and the U-phase arm and the W-phase arm lower arm switch and the V-phase arm upper arm switch All are in a disconnected state; a second step, after completing the first step, turning on the U-phase arm upper arm switch and the V-phase arm and the W-phase arm lower arm switch, and the U-phase arm lower arm The switch and the V-phase arm and the W-phase arm upper arm switch are both in an open state; a third step, after completing the second step, the U-phase arm and the V-phase arm upper arm switch and the W-phase arm The lower arm switch is turned on, and the U phase arm and the V phase arm lower arm switch and the W phase arm upper arm switch are both in an off state; a fourth step is to complete the third step After the step, the V-phase arm upper arm switch and the U-phase arm and the W-phase arm lower arm switch are turned on, and the V-phase arm lower arm switch and the U-phase arm and the W-phase arm upper arm switch are both broken. An open state; a fifth step, after completing the fourth step, turning on the V-phase arm and the W-phase arm upper arm switch and the U-phase arm lower arm switch, and the V-phase arm and the W-phase arm under The arm switch and the upper arm switch of the U-phase arm are both in an open state; and a sixth step, after completing the fifth step, the W-arm upper arm switch and the U-phase arm and the V-phase arm lower arm The switch is turned on, and the W-arm lower arm switch and the U-phase arm and the V-phase arm upper arm switch are both off. According to the control method of the three-phase motor of claim 2, wherein the program for disconnecting the switch of the three-phase motor comprises: in the first step, serially connecting the U-phase arm and the W-phase a first W-phase switch between the two nodes of the arm acts as the switch, and opens the first W-phase switch, wherein the first W-phase open relationship is in series with the U-phase coil of the three-phase motor; In the second step, a first V-phase switch connected between the two nodes of the V-phase arm and the W-phase arm is used as the switch, and the first V-phase switch is turned off, wherein the first a V-phase open relationship is connected in series with the W-phase coil of the three-phase motor; in the third step, a first U-phase switch connected between the two nodes of the U-phase arm and the V-phase arm is Switching, and disconnecting the first U-phase switch, wherein the first U-phase relationship is in series with the V-phase coil of the three-phase motor; in the fourth step, the first W-phase switch is used as the Switching and disconnecting the first W-phase switch; in the fifth step, the first V-phase switch is used as the switch, and the first V-phase switch is turned off; and in the sixth step, The As a U-phase switching of the switch, and the first U-phase disconnect switches. A circuit structure of a three-phase motor, comprising: a U-phase winding module, having a first U-phase switch, a U-phase coil and a second U-phase switch serially connected in series, the first U-phase switch And a U-phase node is disposed between the U-phase coil, and a U-phase change structure contact is disposed between the U-phase coil and the second U-phase switch; and a V-phase winding module has a serial connection a V-phase switch, a V-phase coil and a second V-phase switch, a V-phase node is disposed between the first V-phase switch and the V-phase coil, and a V-phase coil and the second V-phase switch are disposed between the V-phase coil and the V-phase coil V phase change structure contact; a W phase winding module, having a first W phase switch, a W phase coil and a second W phase switch serially connected in series, the first W phase switch and the W phase A W-phase node is disposed between the coils, and a W-phase change structure contact is disposed between the W-phase coil and the second W-phase switch; a three-phase full-bridge converter having a U-phase arm, a V-phase arm, and a a W-phase arm, each of the arms has an upper arm switch and a lower arm switch connected in series, and a series of contacts are formed between the upper arm switch and the lower arm switch, wherein the U-phase arm is connected to the U-phase node a series connection point of the V-phase arm is connected to the V-phase node, and a series connection point of the W-phase arm is connected to the W-phase node; a sensing module has only three rotor position sensing elements, and the three-rotor position sense The measuring component is configured to generate a set of position sensing signals according to a position of a rotor; and a control unit electrically connecting the first U-phase switch and the second U-phase switch of the U-phase winding module, the V-phase winding a first V-phase switch and a second V-phase switch of the line module, a first W-phase switch and a second W-phase switch of the W-phase winding module, and the upper arm switch of the three-phase full-bridge converter An arm switch and each of the rotor position sensing elements of the sensing module to control a winding type presented by the U, V, and W phase coils, and output a set of driving signals to the three phases according to the position sensing signal a full-bridge converter; wherein the U-phase change structure contact is coupled to the first W-phase switch and is not connected to one end of the W-phase node, the V-phase change structure contact is coupled to the first U-phase switch not connected to the U One end of the phase node, the W phase change structure contact is coupled to the first V phase switch not connected to one end of the V phase node, and the second U phase, V phase and W phase No off-phase, V-phase or W-phase coil is connected to the one end of the U are interconnected.