CN105720867B - A kind of BLDCM Drive System - Google Patents

Abstract

A brushless DC motor drive system, characterized in that it includes a transformer connected to the mains, the transformer is connected to an AC/DC rectifier, the AC/DC rectifier is connected to a voltage stabilizer, the voltage stabilizer is connected to an inverter, and the The inverter is connected with the brushless DC motor, the inverter is controlled by an inverter control circuit, and the voltage regulator is a linear voltage regulator. It can stabilize the input voltage of the inverter, improve the control strategy of the inverter at the same time, and ensure that the power consumption of the brushless DC motor is reduced and the efficiency is improved during operation.

Description

A brushless DC motor drive system

technical field

The invention relates to the field of electric appliance control, in particular to a brushless DC motor driving system.

Background technique

With the rapid development of microcomputer control technology, a number of electronic soft-start controllers have been successfully developed in related control engineering fields, which are widely used in the starting process of electric motors, and reduced-voltage starters have been replaced. The current electronic soft start facilities all use the thyristor voltage regulating circuit, and its circuit composition is described as follows: six thyristors, two in anti-parallel and then connected in series to the three-phase power supply, after the system sends a start signal, the microcomputer controls the start The controller system immediately calculates the data, so that the thyristor sends a trigger signal, so that the conduction angle of the thyristor is controlled, and the output voltage is adjusted according to the given output, so as to realize the control of the motor.

In reality, in many cases, when starting a brushless DC motor, first step down the mains power, perform AC/DC conversion, and then pass through the inverter, and realize the control and drive of the motor through the control of the inverter.

However, the existing drive control system has the following problems. The input voltage of the inverter is not stable enough and there is a large ripple, which will be amplified after being processed by the inverter. This means that the instability of the input voltage of the inverter leads to large fluctuations in the output, which leads to increased power consumption of the motor during operation, low efficiency, and insufficient power.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention proposes a brushless DC motor drive system, which can stabilize the input voltage of the inverter, improve the control strategy of the inverter, and ensure the power consumption of the brushless DC motor during operation. decrease and increase efficiency.

In order to achieve the above object, the scheme adopted by the present invention is:

A brushless DC motor drive system, comprising a transformer connected to the mains, the transformer connected to an AC/DC rectifier, the AC/DC rectifier connected to a voltage stabilizer, the voltage stabilizer connected to an inverter, and the inverter connected to brushless DC motor, the inverter is controlled by an inverter control circuit; the voltage regulator includes MOS transistors M ₉ , M ₀ , M _a6 , M ₇ , M ₈ , M _a1 and M _p , and the MOS The sources of the tubes M ₉ , M ₀ , M _a6 , M ₇ , M ₈ , M _a1 and M _p are connected to the power supply VDD, the drains of the MOS tubes are grounded, and the gate of the MOS tube _M9 is connected to the MOS tube M ₀ , the drain of the MOS transistor _M0 is connected to the source of the MOS transistor _M1 , the drain of the MOS transistor _M1 is connected to the drain of the MOS transistor _M3 , and the source of the MOS transistor _M3 grounding; the source of the MOS transistor _M1 is connected to the source of the MOS transistor _M2 , the drain of the MOS transistor _M2 is connected to the drain of the MOS transistor _M4 , and the gate of the MOS transistor _M2 is connected to the reference voltage V _REF , the gate of the MOS transistor _M4 is connected to the gate of the MOS transistor _M3 , the gate of the MOS transistor _M3 is connected to the drain of _M3 , the source of the MOS transistor _M4 is grounded, and the The drain of the MOS transistor _M4 is connected to the gate of the MOS transistor _M5 , the source of the MOS transistor _M5 is grounded, the drain of the MOS transistor _M7 is connected to the drain of the _M5 , and the drain of the MOS transistor _M7 is The drain is connected to the gate of _M7 , the drain of the MOS transistor _M8 is connected to the drain of the MOS transistor _M6 , the gate of the MOS transistor _M6 is connected to the gate of _M4 , and the gate of the MOS transistor _M6 A capacitor CF is connected between the gate and the drain, the source of the MOS transistor _M6 is grounded, the source of the MOS transistor M _a4 is connected to the power supply VDD, and the gate of the MOS transistor M _a4 is connected to the gate of _Ma6 . The drain of the MOS transistor Ma4 is short-circuited to the grid, the drain of the MOS transistor _Ma4 is connected to the drain of the MOS transistor _Ma3 , the source of the MOS transistor _Ma3 is grounded, and the gate of the MOS transistor _Ma1 pole is connected to the drain of M ₈ , the drain of the MOS transistor _Ma1 is connected to the drain of the MOS transistor _Ma2 , the drain of the MOS transistor _Ma2 is short-circuited to the gate, and the source of the MOS transistor _Ma2 Grounded, the drain of the MOS transistor _Mp is grounded sequentially through _R1 and _R2 , the MOS transistor M2 is connected to the drain of _Mp through the capacitor C _M , and the node between the resistor _R1 and the resistor _R2 is connected The gate of _M1 , the drain of the MOS transistor M _p is connected to the voltage output terminal.

The inverter control circuit includes: a mathematical model unit, the mathematical model unit is connected to the inverter through a coordinate converter, a flux linkage automatic control unit, and a switch signal selection unit in sequence; the connection between the flux linkage automatic control unit and the switch signal selection unit There is a zero state module connected between them, the coordinate converter is connected to the switch signal selection unit through the flux linkage amplitude constituting unit and the flux linkage regulator in turn, the mathematical model unit is connected to the switch signal selection unit through the torque regulator, and the conversion The torque regulator is connected to the speed regulator and the frequency regulator respectively.

The speed regulator includes: a speed sensor connected to the brushless DC motor, the actual speed collected by the speed sensor and the set speed are used to calculate the speed difference, and the speed difference is obtained through a differential circuit. The difference value and the rotational speed difference rate respectively obtain the torque Tg through the fuzzy control unit, and connect the direct torque control unit, and the direct torque control unit is connected with the brushless DC motor.

The voltage stabilizer, the inverter, and the inverter control circuit are integrated on the same PCB board.

The voltage regulator is integrated on the first PCB, the inverter is integrated on the second PCB, and the inverter control circuit is integrated on the third PCB.

Also included is a brushless DC motor controller for setting the speed.

The beneficial effect of the present invention is that the voltage stabilizer is controlled by a linear voltage stabilizer, which avoids the overshoot phenomenon of the output voltage, can effectively ensure the stability of the output voltage, and at the same time adopts the direct torque control strategy to control the inverter , making the adjustment of the motor fast and stable with low power consumption and high efficiency.

The fuzzy control strategy is adopted in the process of speed adjustment, and the set torque Tg is obtained by reducing multiple factors into two factors, which simplifies the analysis process and makes the structure of the whole control system simple.

Description of drawings

Fig. 1 structural block diagram of the present invention;

Figure 2 circuit diagram of voltage regulator;

Figure 3 inverter control circuit;

Figure 4. Speed adjustment machine circuit.

Detailed ways

In order to better understand the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1-2, a brushless DC motor drive system includes a transformer connected to the mains, the transformer is connected to an AC/DC rectifier, the AC/DC rectifier is connected to a voltage stabilizer, and the voltage stabilizer is connected to an inverter The inverter is connected to the brushless DC motor, and the inverter is controlled by the inverter control circuit; the voltage regulator includes MOS tubes M ₉ , M ₀ , M _a6 , M ₇ , M ₈ , M _a1 and M _p , the sources of the MOS transistors M ₉ , M ₀ , M _a6 , M ₇ , M ₈ , M _a1 and M _p are connected to the power supply VDD, the drains of the MOS transistors are grounded, and the MOS transistor M The gate of ₉ is connected to the gate of MOS transistor _M0 , the drain of said MOS transistor _M0 is connected to the source of MOS transistor _M1 , and the drain of said MOS transistor _M1 is connected to the drain of MOS transistor _M3 , so The source of the MOS transistor _M3 is grounded; the source of the MOS transistor _M1 is connected to the source of the MOS transistor _M2 , the drain of the MOS transistor _M2 is connected to the drain of the MOS transistor _M4 , and the MOS transistor The gate of _M2 is connected to the reference voltage V _REF , the gate of the MOS transistor _M4 is connected to the gate of the MOS transistor _M3 , the gate of the MOS transistor _M3 is connected to the drain of _M3 , and the MOS transistor M The source of the MOS transistor _M4 is grounded, the drain of the MOS transistor _M4 is connected to the gate of the MOS transistor _M5 , the source of the MOS transistor _M5 is grounded, and the drain of the MOS transistor _M7 is connected to the drain of the _M5 , the drain of the MOS transistor _M7 is connected to the gate of _M7 , the drain of the MOS transistor _M8 is connected to the drain of the MOS transistor _M6 , and the gate of the MOS transistor _M6 is connected to the gate of _M4 , the capacitor CF is connected between the gate and the drain of the MOS transistor _M6 , the source of the MOS transistor _M6 is grounded, the source of the MOS transistor M _a4 is connected to the power supply VDD, and the gate of the MOS transistor M _a4 Connect the gate of _Ma6 , the drain of the MOS transistor Ma4 is short-circuited to the gate, the drain of the MOS transistor _Ma4 is connected to the drain of the MOS transistor _Ma3 , the source of the MOS transistor _Ma3 is grounded, The gate of the MOS transistor _Ma1 is connected to the drain of _M8 , the drain of the MOS transistor _Ma1 is connected to the drain of the MOS transistor _Ma2 , and the drain of the MOS transistor _Ma2 is short-circuited to the gate, so The source of the MOS transistor _Ma2 is grounded, the drain of the MOS transistor _Mp is grounded through _R1 and _R2 in turn, the MOS transistor M2 is connected to the drain of _Mp through the capacitor C _M , and the resistor _R1 and The node between the resistors _R2 is connected to the gate of _M1 , and the drain of the MOS transistor _Mp is connected to the voltage output terminal. I in FIG. 2 is the current flowing through the MOS transistor M9.

As shown in Figure 3, the inverter control circuit includes: a mathematical model unit, the mathematical model unit is connected to the inverter through a coordinate converter, a flux linkage automatic control unit, and a switch signal selection unit; the flux linkage automatic control unit There is a zero-state module connected with the switch signal selection unit, the coordinate converter is connected to the switch signal selection unit through the flux linkage amplitude forming unit and the flux linkage regulator in turn, and the mathematical model unit is connected to the switch signal through the torque regulator A selection unit, the torque regulator is respectively connected to the speed regulator and the frequency regulator.

As shown in Figure 4, the speed regulator includes: a speed sensor connected to the brushless DC motor, the actual speed collected by the speed sensor and the set speed are used to calculate the speed difference, and the speed difference is obtained through a differential circuit The rotational speed difference rate, the rotational speed difference and the rotational speed difference rate respectively obtain the torque Tg through the fuzzy control unit, the torque Tg is connected to the direct torque control unit, and the direct torque control unit is connected to the brushless DC motor.

The voltage stabilizer, the inverter, and the inverter control circuit are integrated on the same PCB board. Integrating all circuits on one circuit makes the whole control structure simple and saves space.

The voltage regulator is integrated on the first PCB, the inverter is integrated on the second PCB, and the inverter control circuit is integrated on the third PCB. Compared with this design, the structure is independent in exchange for sacrificing space. When there is a problem with a functional board, only the PCB board needs to be replaced instead of the entire control board. This design reduces the maintenance cost of the motor and saves resources.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (6)

1. a kind of BLDCM Drive System, it is characterized in that, including being electrically connected transformer, transformer connection AC/DC with city Rectifier, the AC/DC rectifiers connect voltage-stablizer, and the voltage-stablizer connects inverter, and the inverter connects brushless direct-current Motor, the inverter are controlled by inverter control circuit；The voltage-stablizer includes metal-oxide-semiconductor M₉、M₀、M_a6、M₇、M₈、M_a1And M_p, the metal-oxide-semiconductor M₉、M₀、M_a6、M₇、M₈、M_a1And M_pSource electrode meet power vd D, the metal-oxide-semiconductor M₉Grounded drain, it is described Metal-oxide-semiconductor M₉Grid with drain electrode connect, the metal-oxide-semiconductor M_a6Drain electrode connection metal-oxide-semiconductor M₂Source electrode, the metal-oxide-semiconductor M₉Grid connect Meet metal-oxide-semiconductor M₀Grid, the metal-oxide-semiconductor M₀Drain electrode meet metal-oxide-semiconductor M₁Source electrode, the metal-oxide-semiconductor M₁Drain electrode connection metal-oxide-semiconductor M₃'s Drain electrode, the metal-oxide-semiconductor M₃Source electrode ground connection；The metal-oxide-semiconductor M₁Source electrode connection metal-oxide-semiconductor M₂Source electrode, the metal-oxide-semiconductor M₂Leakage Pole connection metal-oxide-semiconductor M₄Drain electrode, the metal-oxide-semiconductor M₂Grid connection reference voltage V_REF, the metal-oxide-semiconductor M₄Grid connection MOS Pipe M₃Grid, the metal-oxide-semiconductor M₃Grid connection M₃Drain electrode, the metal-oxide-semiconductor M₄Source electrode ground connection, the metal-oxide-semiconductor M₄Leakage Pole connection metal-oxide-semiconductor M₅Grid, the metal-oxide-semiconductor M₅Source electrode ground connection, the metal-oxide-semiconductor M₇Drain electrode connection M₅Drain electrode, it is described Metal-oxide-semiconductor M₇Drain electrode connection M₇Grid, the metal-oxide-semiconductor M₇Grid and metal-oxide-semiconductor M₈Grid connection, the metal-oxide-semiconductor M₈Leakage Pole connection metal-oxide-semiconductor M₆Drain electrode, the metal-oxide-semiconductor M₆Grid connection M₄Grid, the metal-oxide-semiconductor M₆Grid and drain electrode between Connect capacitance C_F, the metal-oxide-semiconductor M₆Source electrode ground connection, metal-oxide-semiconductor M_a4Source electrode meet power vd D, the metal-oxide-semiconductor M_a4Grid connection M_a6Grid, the drain electrode of the metal-oxide-semiconductor Ma4 and grid short circuit, the metal-oxide-semiconductor M_a4Drain electrode connection metal-oxide-semiconductor M_a3Drain electrode, institute State metal-oxide-semiconductor M_a3Source electrode ground connection, the metal-oxide-semiconductor M_a1Grid connection M₈Drain electrode, the metal-oxide-semiconductor M_a1Drain electrode connection metal-oxide-semiconductor M_a2Drain electrode, the metal-oxide-semiconductor M_a2Drain electrode and grid short circuit, the metal-oxide-semiconductor M_a2Source electrode ground connection, the metal-oxide-semiconductor M_pGrid Connect the metal-oxide-semiconductor M₈Drain electrode, the metal-oxide-semiconductor M_pDrain electrode pass sequentially through resistance R₁With resistance R₂Ground connection, the metal-oxide-semiconductor M₂'s Drain electrode passes through capacitance C_MConnect M_pDrain electrode, the resistance R₁With resistance R₂Between node connection M₁Grid, the metal-oxide-semiconductor M_p Drain electrode connect voltage output end.

2. a kind of BLDCM Drive System as described in claim 1, it is characterized in that, the inverter control circuit packet It includes：Mathematical model unit, the mathematical model unit pass sequentially through coordinate converter, magnetic linkage Automatic Control Unit, switching signal selection Unit connects inverter；Nought state module, the seat are connected between the magnetic linkage Automatic Control Unit and switching signal selecting unit Mark converter passes sequentially through magnetic linkage amplitude Component units and flux regulating device connecting valve signal behavior unit, the mathematical model Unit connects speed regulator and frequency respectively by torque controller connecting valve signal behavior unit, the torque controller Adjuster.

3. a kind of BLDCM Drive System as claimed in claim 2, it is characterized in that, the speed regulator includes： The speed probe being connect with brshless DC motor, the actual speed that the speed probe is acquired seek rotating speed with setting speed Difference, the rotating speed difference obtain rotating speed difference rate by differential circuit, and rotating speed difference passes through respectively with rotating speed difference rate Fuzzy control unit connects Direct Torque Control unit, Direct Torque Control unit connection brshless DC motor.

4. a kind of BLDCM Drive System as claimed in claim 3, it is characterized in that, the voltage-stablizer, inverter is inverse Become device control circuit to be integrated on same pcb board.

5. a kind of BLDCM Drive System as claimed in claim 3, it is characterized in that, the voltage-stablizer is integrated in first On pcb board, the inverter is integrated on the second pcb board, and the inverter control circuit is integrated on third pcb board.

6. a kind of BLDCM Drive System as described in claim 4 or 5, it is characterized in that, further include brushless dc Machine controller, for setting speed.