阅读说明：本技术 多相无刷直流电机及其驱动方法 (multiphase brushless DC motor and driving method thereof ) 是由 刘振韬 于 2015-12-02 设计创作，主要内容包括：本发明涉及一种多相无刷直流电机及其驱动方法,其中电机中驱动模块包括依次电连接的控制器、每一相的H桥单级逆变器和独立相线圈绕组(1),方法包括：601)控制器输出频率与幅度相同的脉宽调制的正弦波来分别驱动每一相的H桥单级逆变器；每相邻二个所述相线圈绕组对应的所述脉宽调制的正弦波之间具有非零相位差且相位差是相同的；602)每一相的H桥单级逆变器向各自对应电连接的独立相线圈绕组输出对应相位的正弦波驱动电压或正弦波驱动电流。这种多相无刷直流电机及其驱动方法,能实现完美正弦的电压或电流驱动,从而提高效率并降低噪音。(the invention relates to a multiphase brushless direct current motor and a driving method thereof, wherein a driving module in the motor comprises a controller, an H-bridge single-stage inverter and an independent phase coil winding (1), which are sequentially and electrically connected, and the method comprises the following steps: 601) the controller outputs a pulse width modulated sine wave with the same frequency and amplitude to respectively drive the H-bridge single-stage inverter of each phase; the sine waves of the pulse width modulation corresponding to every two adjacent phase coil windings have non-zero phase difference and the phase difference is the same; 602) and the H-bridge single-stage inverter of each phase outputs sine wave driving voltage or sine wave driving current of a corresponding phase to the independent phase coil windings which are correspondingly and electrically connected. The multiphase brushless direct current motor and the driving method thereof can realize perfect sinusoidal voltage or current driving, thereby improving the efficiency and reducing the noise.)

1. A multi-phase brushless direct current motor comprises a direct current motor body, a plurality of phase coil windings and a driving module, and is characterized in that the phase coil windings are independent direct current motor phase coil windings without common end points.

2. The multiphase brushless dc motor of claim 1, wherein the drive module is configured to output sinusoidal voltages and currents to drive each set of phase coil windings.

3. The multiphase brushless dc motor according to claim 1 or 2, wherein the pulse width modulated sine waves corresponding to each adjacent two of the phase coil windings have a non-zero phase difference therebetween and the phase differences are the same.

4. A multiphase brushless dc motor according to any of the preceding claims, wherein the drive module comprises:

The controller, each different output end controls the control foot of the H bridge single-stage inverter of each phase of electric connection respectively, its output signal is: the pulse width modulated sine wave respectively drives the H-bridge single-stage inverter of each phase, and the frequency and the amplitude of each pulse width modulated sine wave signal are the same;

The output end of each H-bridge single-stage inverter of each phase corresponds to the two ends of the corresponding phase coil winding;

The pulse width modulated sine waves corresponding to every two adjacent phase coil windings have non-zero phase difference and the phase difference is the same.

5. a multiphase brushless dc motor according to any of the preceding claims, wherein the phase coil windings are 2 groups, 3 groups or any multiple of 2 and 3.

6. A multiphase brushless dc motor according to any of the preceding claims, wherein said controller is an analog or digital FPGA circuit unit.

7. a driving method of a multiphase brushless direct current motor is characterized in that a controller is utilized to electrically connect an H-bridge single-stage inverter corresponding to two ends of an independent phase coil winding (1) with an output end of each phase, and the driving method comprises the following steps:

501) the controller outputs a pulse width modulated sine wave with the same frequency and amplitude to respectively drive the H-bridge single-stage inverter of each phase; the sine waves of the pulse width modulation corresponding to every two adjacent phase coil windings have non-zero phase difference and the phase difference is the same;

502) the H-bridge single-stage inverter of each phase outputs sine wave driving voltage or sine wave driving current of the corresponding phase to the independent phase coil winding (1) which is electrically connected correspondingly.

8. The driving method of the multiphase brushless dc motor according to claim 8, wherein the H-bridge single-stage inverter of each phase is operated in a single-stage mode.

9. The driving method of a multiphase brushless dc motor according to claim 8, wherein the phase coil windings are 2 groups, 3 groups, or any multiple of 2 and 3.

10. the driving method of the multiphase brushless dc motor as claimed in claim 8, wherein in order to drive the three-phase dc motor, the sine wave data of the phase current of the second phase winding 120 degrees behind the first phase winding is obtained by adding the 32-bit full scale value 1/3 to the angle value, and the sine wave data of the phase current of the third phase winding 240 degrees behind the first phase winding is also obtained by adding the 32-bit full scale value 2/3 to the angle value, and in this order, the currents flow into the phase windings one after another, thereby rotating the motor.

Technical Field

the invention relates to a brushless direct current motor, in particular to a multiphase brushless direct current motor and a driving method thereof.

Background

Compared with other motors, the brushless direct current motor has the advantages of energy conservation and high reliability, and is more and more popular. Single phase dc drive is achieved by single H-bridge inversion with a hall effect sensor, and in addition, conventional three phase dc motors, whether sensor based or sensorless, are typically driven with three half-bridges, with the phase coil windings typically using star connections, as shown in fig. 1, with three phase coil windings 1 having common terminals. Trapezoidal, sinusoidal, field-oriented control is the most common method of commutation. In this case, however, the inverter outputs only a sinusoidal-like voltage or current that would cause excessive power consumption and audible noise for a dc brushless motor driven by such voltage or current.

Disclosure of Invention

The technical problem to be solved by the invention is how to provide a multiphase brushless direct current motor and a driving method thereof, which breaks through the conventional coil winding star connection method and drives each group of coils by using more perfect sinusoidal voltage and current, thereby greatly improving the performance of the direct current brushless motor.

The first technical problem of the present invention is solved by constructing a multiphase brushless dc motor, which includes a motor body and a driving module thereof, wherein the driving module includes a phase coil winding, and the driving module further includes:

The controller, each different output end controls the control foot of the H bridge single-stage inverter of each phase of electric connection respectively, its output signal is: the pulse width modulated sine wave respectively drives the H-bridge single-stage inverter of each phase, and the frequency and the amplitude of each pulse width modulated sine wave signal are the same;

The output end of each H-bridge single-stage inverter of each phase corresponds to the two ends of the corresponding phase coil winding;

The phase coil winding is an independent phase coil winding without a common end point; the pulse width modulated sine waves corresponding to every two adjacent phase coil windings have non-zero phase difference and the phase difference is the same.

According to the multiphase brushless direct current motor provided by the invention, the phase is also called included angle, and the phase difference is also called included angle difference.

According to the multiphase brushless direct current motor provided by the invention, the direct current motor stator coil winding is 2 groups, 3 groups or any multiple of 2 and 3.

According to the multiphase brushless dc motor provided by the present invention, the controller is an FPGA (Field-Programmable Gate Array) or other electronic component having a Programmable logic Array. The pulse width modulated sine wave is implemented by a CORDIC (Coordinate Rotation Digital Computer) algorithm and a multiplier.

According to the multiphase brushless dc motor provided by the present invention, the controller is an analog or digital circuit unit. The pulse width modulated sine wave is implemented by a hardware circuit.

Another technical problem of the present invention is solved by constructing a driving method of a multiphase brushless dc motor, which is characterized in that an H-bridge single-stage inverter electrically connected to both ends of a coil winding of a corresponding independent phase by using a controller and an output terminal of each phase, comprising the steps of:

501) the controller outputs a pulse width modulated sine wave with the same frequency and amplitude to respectively drive the H-bridge single-stage inverter of each phase; the sine waves of the pulse width modulation corresponding to every two adjacent phase coil windings have non-zero phase difference and the phase difference is the same;

502) and the H-bridge single-stage inverter of each phase outputs sine wave driving voltage or sine wave driving current of a corresponding phase to the independent phase coil winding which is correspondingly and electrically connected.

According to the driving method of the multiphase brushless direct current motor provided by the invention, each H-bridge single-stage inverter preferably works in a single-stage mode.

According to the driving method of the multiphase brushless direct current motor, the stator coil winding of the direct current motor is 2 groups, 3 groups or any multiple of 2 and 3.

The multiphase brushless direct current motor and the driving method thereof break through the conventional coil winding star connection method, and compared with the prior art, the multiphase brushless direct current motor has the following advantages:

1. Each winding uses an H-bridge single-stage inverter;

2. the coil windings have no common end points and do not influence each other;

3. The algorithm is simple, and all windings are driven by smooth pure sine waves.

Drawings

The invention is further described in detail below with reference to the figures and the specific embodiments.

Fig. 1 is a schematic circuit configuration diagram of a conventional three-phase brushless dc motor;

Fig. 2 is a schematic circuit configuration diagram of a three-phase brushless dc motor according to a preferred embodiment of the present invention;

FIG. 3 is a schematic circuit diagram of the H-bridge single stage inverter of FIG. 1;

FIG. 4 is a pulse width modulated sine wave timing diagram of the output of the H-bridge single stage inverter of FIG. 3;

FIG. 5 is a schematic truth table diagram between the control signal and the output voltage of the H-bridge single stage inverter of FIG. 3;

Fig. 6 is a schematic circuit diagram of a two-phase brushless dc motor according to a preferred embodiment of the present invention.

Wherein the reference numbers: 1-phase coil winding.

Detailed Description

The structure of the three-phase brushless direct current motor of the preferred embodiment of the invention is shown in fig. 2, three H-bridge single-stage inverters are used for driving the three-phase brushless direct current motor, and three groups of independent phase coil windings 1 without common end points are configured in the motor, so that all the windings are driven by smooth pure sine waves, the phase coil windings 1 of the motor have minimum power harmonics, and the maximum driving efficiency is achieved. In addition, the motor uses a powerful high-speed FPGA to simultaneously drive three H-bridge single-stage inverters.

the H-bridge single-stage inverter in the preferred embodiment of the present invention is constructed as shown in FIG. 3 and driven by four gates g1, g2, g3 and g4 to output a motor drive signal V _AB to achieve the best switching efficiency, all inverters are driven by gate signals and operated in single-stage mode, as shown in FIG. 4, where V _AN is the voltage of A with respect to the virtual operating ground N and V _BN is the voltage of A with respect to the virtual operating ground N.

The three-phase brushless direct current motor of the preferred embodiment of the invention has the following specific working principle:

Each inverter driven by the gate is driven by a set of 4 digital pins corresponding to the FPGA. In order to allow the signal driving the windings to be a perfectly smooth pure sine wave, a sinusoidal pulse width modulation method is used, which delivers a PWM signal of constant amplitude but varying pulse width duty cycle to each set of H-bridge inverters at each cycle. A sine wave PWM signal of varying duty cycle flows over each winding so that the voltage waveform over the winding resembles an AC signal and all inverters are driven with gate signals for best switching efficiency, operating in single stage mode. A high-speed FPGA with powerful functions in a three-phase brushless direct current motor is embedded with a CORDIC sine algorithm, and an angle is determined by 32 data bits and ranges from 0 degree to 360 degrees. The sine of the angle (from +1.0 to-1.0) is represented by 24 bits of data, the minimum being accurate to 2 seconds, the sign of the data determining the direction of the current flowing through the winding, and the duty cycle of the PWM signal will be derived by multiplying the 24 bits of data of the angle sine by the switching frequency through a 24 bit by 24 bit multiplier. A constant single-stage modulated sine wave is generated by adding a constant value and the accumulated angle value at fixed time intervals, and changing the constant value or time interval results in a change in the frequency of the sine wave.

in this embodiment, in order to drive the three-phase dc motor, the 32-bit full scale value 1/3 is added to the angle value to obtain the sine wave data of the phase current of the second phase winding 120 degrees behind the first phase winding, and the 32-bit full scale value 2/3 is also added to the angle value to obtain the sine wave data of the phase current of the third phase winding 240 degrees behind the first phase winding.

fig. 5 shows the truth relation between the control signal given by the FPGA to the H-bridge inverter and the phase voltage output by the inverter bridge to the motor.

the same method can be used for driving a different type of multiphase motor as long as the phase angle is the same, for example, a two-phase brushless dc motor with a phase angle of 90 degrees, and the circuit structure is shown in fig. 6. The FPGA control algorithm of the two-phase direct current motor is similar to that of the three-phase direct current motor, the truth value relation between a control signal given to an H bridge inverter by the FPGA of the two-phase direct current motor and a phase voltage output to the motor by an inverter bridge is the same as that of the three-phase direct current motor, and the description is not repeated.

the above-mentioned embodiments are only preferred embodiments of the present invention, and all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.