阅读说明：本技术 一种无刷直流电机电动与再生制动一体化控制方法 (Brushless direct current motor electric and regenerative braking integrated control method ) 是由 樊平 孙建平 李洪亮 袁宇凤 李宇 于 2020-11-26 设计创作，主要内容包括：本发明涉及一种无刷直流电机电动与再生制动一体化控制方法。所述一体化控制方法应用于三相六状态Y形接法的无刷直流电机,包括：对参与工作的两个桥臂当中的一个桥臂的上功率开关管和下功率开关管施加互补驱动信号,对另一个桥臂的下功率开关管施加恒通的驱动信号,构成降压斩波BUCK/升压斩波BOOST电路,实现电流双方向流通；当所述无刷直流电机工作在电动状态时,所述无刷直流电机的电路处于BUCK模式,通过降压斩波方式调压调速；当所述无刷直流电机工作在再生制动状态时,所述无刷直流电机的电路处于BOOST模式,通过升压斩波方式实现再生制动状态下的调速。本发明能够根据路况的变化自动在电动状态与制动状态之间自由转换。(The invention relates to an electric and regenerative braking integrated control method for a brushless direct current motor. The integrated control method is applied to a three-phase six-state Y-shaped connection brushless direct current motor, and comprises the following steps: complementary driving signals are applied to an upper power switching tube and a lower power switching tube of one of two bridge arms which participate in working, and a constant-connection driving signal is applied to a lower power switching tube of the other bridge arm, so that a BUCK chopper/BOOST chopper BOOST circuit is formed, and bidirectional current circulation is realized; when the brushless direct current motor works in an electric state, a circuit of the brushless direct current motor is in a BUCK mode, and voltage and speed are regulated and regulated in a BUCK chopping mode; when the brushless direct current motor works in a regenerative braking state, a circuit of the brushless direct current motor is in a BOOST mode, and speed regulation in the regenerative braking state is achieved through a BOOST chopping mode. The invention can automatically and freely switch between the electric state and the braking state according to the change of road conditions.)

1. An integrated control method for electric and regenerative braking of a brushless direct current motor, which is applied to a three-phase six-state Y-connection brushless direct current motor, and comprises the following steps:

complementary driving signals are applied to an upper power switching tube and a lower power switching tube of one of two bridge arms which participate in working, and a constant-connection driving signal is applied to a lower power switching tube of the other bridge arm, so that a BUCK chopper/BOOST chopper BOOST circuit is formed, and bidirectional current circulation is realized;

when the brushless direct current motor works in an electric state, a circuit of the brushless direct current motor is in a BUCK mode, and voltage and speed are regulated and regulated in a BUCK chopping mode; when the brushless direct current motor works in a regenerative braking state, a circuit of the brushless direct current motor is in a BOOST mode, and speed regulation in the regenerative braking state is achieved through a BOOST chopping mode.

2. The integrated control method for electric and regenerative braking of the brushless DC motor according to claim 1, wherein the first arm of the brushless DC motor comprises a first power switching tube VT1 and a fourth power switching tube VT4 connected in series;

the second bridge arm of the brushless direct current motor comprises a third power switch tube VT3 and a sixth power switch tube VT6 which are connected in series;

the third bridge arm of the brushless dc motor includes a fifth power switch tube VT5 and a second power switch tube VT2 connected in series.

3. The integrated control method for electric and regenerative braking of the brushless direct current motor according to claim 2, wherein the conducting logic expression of the first power switching tube VT1 is as follows:

the on logic expression of the second power switching tube VT2 is:

the on logic expression of the third power switching tube VT3 is:

the on logic expression of the fourth power switching tube VT4 is:

the on logic expression of the fifth power switching tube VT5 is:

the conduction logic expression of the sixth power switching tube VT6 is: wherein Ha is an A-phase Hall signal; hb is a B-phase Hall signal; hc is a C-phase Hall signal;is the logical negation of the A-phase Hall signal;is the logical negation of the B-phase Hall signal;is the logical negation of the C-phase Hall signal; PWMA is A phase pulse width modulation signal, PWMB is B phase pulse width modulation signal, PWMA and PWMB are pulse width modulation signal with complementary duty ratio; the upper power switch tube is sequentially VT1, VT3 and VT5, and the lower power switch tube is sequentially VT4, VT6 and VT 2; and n is a logical AND and u is a logical OR.

Technical Field

The invention relates to the field of speed stabilization control of brushless direct current motor electromotion and regenerative braking state conversion, in particular to an electromotion and regenerative braking integrated control method of a brushless direct current motor.

Background

If the electric automobile directly driven by the permanent magnet brushless direct current motor runs in a constant-speed cruise mode or an intelligent driving mode and meets a slope, the motor is required to be switched back and forth between an electric state and a regenerative braking state so as to ensure that the automobile runs at a constant speed. During braking, the energy of the automobile when going downhill can be absorbed and converted into electric energy to charge the battery, and the endurance mileage of the automobile is improved.

For the electric and braking control of the brushless direct current motor, the current method is that the whole vehicle controller sends an operation state control command, and the motor control respectively adopts different modulation methods to realize the electric and braking according to the control command. In a constant-speed cruise mode, the vehicle control unit only sends a rotating speed command to the motor controller, and requires the motor to operate at a constant rotating speed without an operating state command; and if the road is rugged and uneven and the slope is more, the more frequent the motor is switched between the electric state and the braking state, and the speed stabilization control cannot be realized.

The traditional brushless direct current motor control adopts two different PWM modulation methods and phase change logic under two states of electric driving and regenerative braking. Thus, when switching between the two states, a run state command is necessary, otherwise the modulation method and the commutation logic cannot be changed. Therefore, the traditional control method adopts different phase logics in two states of electric driving and regenerative braking, and cannot realize the automatic switching of the two states of the electric driving and the regenerative braking under the conditions of only a rotating speed control command and no running state control command.

Disclosure of Invention

The invention aims to provide an electric and regenerative braking integrated control method of a brushless direct current motor, which aims to solve the problem that the traditional control method adopts different phase logics in two states of electric and regenerative braking, and can not realize automatic switching between the two states of electric and regenerative braking under the condition of only a rotating speed control command and no operating state control command.

In order to achieve the purpose, the invention provides the following scheme:

an integrated control method for electric and regenerative braking of a brushless direct current motor, which is applied to a three-phase six-state Y-connection brushless direct current motor, comprises the following steps:

complementary driving signals are applied to an upper power switching tube and a lower power switching tube of one of two bridge arms which participate in working, and a constant-connection driving signal is applied to a lower power switching tube of the other bridge arm, so that a BUCK chopper/BOOST chopper BOOST circuit is formed, and bidirectional current circulation is realized;

when the brushless direct current motor works in an electric state, a circuit of the brushless direct current motor is in a BUCK mode, and voltage and speed are regulated and regulated in a BUCK chopping mode; when the brushless direct current motor works in a regenerative braking state, a circuit of the brushless direct current motor is in a BOOST mode, and speed regulation in the regenerative braking state is achieved through a BOOST chopping mode. The motor can be freely switched between the two states of electric and regenerative braking according to the change of the load without switching commands.

Optionally, the first bridge arm of the brushless dc motor includes a first power switch tube VT1 and a fourth power switch tube VT4 connected in series;

the second bridge arm of the brushless direct current motor comprises a third power switch tube VT3 and a sixth power switch tube VT6 which are connected in series;

the third bridge arm of the brushless dc motor includes a fifth power switch tube VT5 and a second power switch tube VT2 connected in series.

Optionally, the on logic expression of the first power switching tube VT1 is:

the on logic expression of the second power switching tube VT2 is:

the on logic expression of the third power switching tube VT3 is:

the on logic expression of the fourth power switching tube VT4 is:

the on logic expression of the fifth power switching tube VT5 is:

the conduction logic expression of the sixth power switching tube VT6 is: wherein Ha is an A-phase Hall signal; hb is a B-phase Hall signal; hc is a C-phase Hall signal;is the logical negation of the A-phase Hall signal;is the logical negation of the B-phase Hall signal;is the logical negation of the C-phase Hall signal; PWMA is an A-phase pulse width modulation signal and PWMB is a B-phase pulse width modulation signalPWMA and PWMB are pulse width modulation signals with complementary duty ratios; the upper power switch tube is sequentially VT1, VT3 and VT5, and the lower power switch tube is sequentially VT4, VT6 and VT 2; and n is a logical AND and u is a logical OR.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects: the invention provides an electric and regenerative braking integrated control method of a brushless direct current motor, which is characterized in that complementary driving signals are applied to an upper power switch tube and a lower power switch tube of one of two bridge arms which participate in working, a constant-current driving signal is applied to a lower power switch tube of the other bridge arm, a certain power tube of a three-phase bridge and a motor winding inductance form a BUCK chopper/BOOST chopper BOOST circuit through phase change logic and a modulation method shown in figure 2, and the bidirectional circulation of current is realized. Based on the control method, the working state of the motor does not need to be judged when the motor is switched between the electric state and the regenerative braking state, the phase change logic does not need to be changed, and the motor can be automatically and freely switched between the two states according to the change of the road condition.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a main power circuit diagram of a permanent magnet brushless DC motor;

FIG. 2 is a control diagram of unipolar modulation electromotive and regenerative braking integrated commutation logic;

FIG. 3 is a conventional commutation logic diagram of a brushless DC motor in an electromotive state;

FIG. 4 is a conventional commutation logic diagram for a brushless DC motor during regenerative braking;

FIG. 5 is a schematic diagram of a control system for implementing integrated control based on DSP and CPLD;

fig. 6 is a schematic diagram of a control system for realizing integrated control based on a DSP.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide an electric and regenerative braking integrated control method of a brushless direct current motor, which realizes the use of unified phase change logic for electric and braking, does not need to judge the working state of the motor when the motor is switched between the electric state and the regenerative braking state, does not need to change the phase change logic, and automatically and freely switches between the two states according to the change of road conditions.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The invention discloses a brushless direct current motor electric and regenerative braking integrated control method aiming at a permanent magnet brushless direct current motor adopting a three-phase six-state Y-shaped connection method, and the method is characterized in that fig. 1 is a main power circuit diagram of the permanent magnet brushless direct current motor, the main power circuit is shown in fig. 1, and a power tube adopts an Insulated Gate Bipolar Transistor (IGBT).

When the motor is switched between the electric state and the regenerative braking state, the working state of the motor does not need to be judged, the phase change logic does not need to be changed, and the motor can be automatically and freely switched between the two states according to the change of road conditions. The modulation method and commutation logic are shown in fig. 2. The conduction logic expression of each switching tube is as follows:

wherein: ha, Hb and Hc represent three-phase Hall signals;a logical not representing a hall signal; PWMA and PWMB represent pulse width modulated signals with complementary duty cycles (opposite phases and with dead zones). VT 1-VT 6 represent power switch tubes of a brushless motor three-phase bridge, the sequence of the upper three tubes is VT1, VT3 and VT5, and the sequence of the lower three tubes is VT4, VT6 and VT 2. And n denotes a logical and u denotes a logical or.

For a two-phase conduction three-phase six-state control brushless direct current motor, six phase change intervals are provided, two switching tubes are conducted in each phase change interval, a traditional phase change logic is shown in fig. 3 in an electric state, and is shown in fig. 4 in a regenerative braking state. The typical modulation mode in the motoring state is the HPWM _ LON mode, i.e. the upper tube is PWM modulated and the lower tube is constantly on. For a three-phase inverter bridge, in combination with fig. 1 and 3, it can be seen that two bridge arms participate in modulation in any phase conversion interval, and the other bridge arm does not work. Only one switch of the bridge arm participating in the modulation applies a driving signal, either a PWM modulation signal or a constant-on driving signal.

The invention applies complementary unipolar modulation signals to a certain bridge arm participating in modulation, unifies electric braking and regenerative braking, and realizes unified phase change, as shown in fig. 2. The idea is that complementary driving signals are applied to an upper power tube and a lower power tube of a certain bridge arm, and a constant-current driving signal is applied to a lower tube of the other bridge arm to form a BUCK/BOOST circuit, so that current can flow in two directions. As shown in figure 3, when the circuit works in an electric state, the circuit is in a BUCK mode, voltage regulation and speed regulation are realized through BUCK chopping, and as shown in figure 4, when the circuit works in a regenerative braking state, the circuit is in a BOOST mode, and speed regulation in the regenerative braking state is realized.

By applying the same idea, the existing modulation methods can be as follows: and a series of modulation methods can be designed to realize integrated control of electric braking and regenerative braking by modifying PWM _ ON, ON _ PWM, HPWM _ LON, HON _ LPWM, PWM _ OFF, OFF _ PWM, HPWM _ LOFF, HOFF _ LPWM, HPWM _ LPWM and the like.

Based on the brushless dc motor electric and regenerative braking integrated control method provided by the present invention, the present invention is further explained by the following two embodiments.

Example one

The control method provided by the invention can be realized in a brushless direct current motor system controlled under a DSP + CPLD framework. Under the framework, the CPLD is used as a peripheral and is connected with the DSP through a parallel data bus address bus and a control bus. Fig. 5 is a schematic diagram of a control system for implementing integrated control based on a DSP and a CPLD, as shown in fig. 5. And the DSP changes the duty ratio in real time according to a control algorithm to form a complementary PWM signal and a commutation logic selection signal which are sent to the CPLD. And the CPLD performs logical operation according to the Hall position signal of the brushless direct current motor, the complementary PWM signal sent by the DSP and the commutation logic selection signal to form a driving signal to control a main power circuit of the brushless direct current motor, so that the stability and the control of the rotating speed of the motor are realized.

The method comprises the following concrete steps:

the first step is as follows: in a DSP control program of the brushless direct current motor, output control of an ePWM control module is configured, so that GPIO0 and GPIO1 have PWM functions.

Gpio ctrl regs. gpamux1.bit. gpio0 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio1 ═ 1; // configuration as PWM function

Gpio ctrl. gpapud. bit. gpio0 ═ 0; // enabling internal pullup

Gpio1 ═ 0, gpio ctrl regs. // enabling internal pullup

The second step is that: in a DSP control program of the brushless direct current motor, the dead zone control of an ePWM control module is configured, so that the complementary PWM signals PWMA and PWMB have a dead zone.

Epwm1regs.dbctl.bit.out _ MODE ═ 0x 03; // enable dead band control

Epwm1regs.dbctl.bit.polsel ═ 0x 02; // polarity selection of PWM

Epwm1regs.dbred 100; // setting dead time

Epwm1regs.dbfed 100; // setting dead time

Two paths of complementary PWM signals PWMA and PWMB with dead zones can be output through the two steps of DSP.

The third step: the phase change logic for realizing the integrated control of electric and regenerative braking is designed according to the following relational expression by designing unipolar modulation in a CPLD control program.

The control method provided by the invention is realized in a brushless direct current motor controller formed by a DSP28335 and a CPLD. The DSP outputs two complementary PWM signals through EPWM1A and EPWM1B ports, and the two complementary PWM signals are sent to the CPLD, and the CPLD forms a driving signal of the power switch tube according to the input Hall position signals Ha, Hb and Hc.

Example two

The control method provided by the invention can also be realized in a brushless direct current motor system controlled by a DSP. Fig. 6 is a schematic diagram of a control system for implementing integrated control based on DSP, as shown in fig. 6, wherein M1 is a brushless dc motor. The DSP captures Hall signals through a capture port (CAP port), then realizes phase conversion logic of integration of electromotion and regenerative braking according to unipolar modulation, and controls a duty ratio generated by an algorithm, and finally forms a driving signal to control a main power circuit of the brushless direct current motor, thereby realizing the stabilization and control of the rotating speed of the motor. The following shows the implementation steps of the motor in one rotation direction and one commutation interval (such as the 30-90 ° interval in fig. 2), and the commutation logic in the opposite direction is similar to the implementation of other commutation intervals.

The method comprises the following concrete steps:

the first step is as follows: in a DSP control program of the brushless direct current motor, output control of an ePWM control module is configured, so that GPIO0 and GPIO1 have PWM functions.

Gpio ctrl regs. gpamux1.bit. gpio0 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio1 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio2 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio3 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio4 ═ 1; // configuration as PWM function

Gpio ctrl regs. gpamux1.bit. gpio5 ═ 1; // configuration as PWM function

Gpio ctrl. gpapud. bit. gpio0 ═ 0; // enabling internal pullup

Gpio1 ═ 0, gpio ctrl regs. // enabling internal pullup

Gpio ctrl. gpapud. bit. gpio2 ═ 0; // enabling internal pullup

Gpio3 ═ 0, gpio ctrl regs. // enabling internal pullup

Gpio ctrl. gpapud. bit. gpio4 ═ 0; // enabling internal pullup

Gpio ctrl regs. gpapud. bit. gpio5 ═ 0; // enabling internal pullup

The second step is that: and designing a commutation function.

HallAngle is the binary value of Hall signals Ha, Hb and Hc, is synthesized into hexadecimal numbers according to the sequence, and is converted into decimal values which are 5, 1, 3, 4, 6 and 2 respectively.

The third step: and designing a modulation function of each commutation interval according to the conducting logic expression of each switch mentioned in the summary of the invention.

Pwm1APWM2B ()// for driving VT1, VT6

{

EALLOW; // close interrupt

Epwm1regs.aqcsfrc.bit.csfa ═ 0; // EPwm1A output PWM

Epwm1regs. aqcsfrc. bit. csfb ═ 0; // EPwm1B output PWM

Epwm2regs. aqcsfrc. bit. csfa ═ 0x 02; // EPwm2A forced high output

Epwm2regs. aqcsfrc. bit. csfb ═ 0x 02; // EPwm2B forced high output

Epwm3regs.aqcsfrc.bit.csfa ═ 0x 02; // EPwm3A forced high output

Epwm3regs.aqcsfrc.bit.csfb ═ 0x 01; // EPwm3B forced low output

Epwm2regs.dbctl.bit.out _ MODE ═ 0; // turn off dead band enable

Epwm3regs.dbctl.bit.out _ MODE ═ 0; // turn off dead band enable

Epwm1regs.aqctla.bit.cau ═ 0x 01; // count value equals the value of the compare register and output Low

Epwm1regs.aqctla.bit.cad ═ 0x 02; // count value equal to compare register value outputs high

Epwm1regs.dbctl.bit.in _ MODE ═ 0; // set signal source

Epwm1regs.dbctl.bit.out _ MODE ═ 0; // enable dead band

Epwm1regs.dbctl.bit.polsel ═ 0x 02; // polarity selection

Epwm1regs.dbfed 40; // setting dead time

Epwm1regs.dbred 40; // setting dead time

EDIS; // open interrupt

}

Function PWM1APWM3B (); PWM2APWM3B (); PWM2APWM1B (); PWM3APWM1B (); PWM3APWM2B (); is similar to PWM1APWM2B ().

The invention provides an electric and regenerative braking integrated control method of a brushless direct current motor, which realizes smooth transition of an electric and regenerative braking state and speed stabilization control under the two states.

Compared with the prior art, the invention has the following advantages:

(1) the method provided by the invention is completely the same as the existing hardware circuit for driving the brushless DC motor, and only the software is required to be modified to change the commutation logic and the modulation method of the brushless DC motor.

(2) The state switching command is not needed, and the state switching between the electric state and the regenerative braking state can be automatically carried out. The traditional modulation method and phase change logic of brushless direct current motor electromotion and braking regenerative braking can not realize automatic transition from electromotion to regenerative braking, control instructions need to be sent manually from electromotion to braking, and then the phase change logic is changed to realize state switching. The control method provided by the invention can realize the integrated control of the electric operation and the regenerative braking, can realize the smooth transition from the electric operation to the regenerative braking without the instruction of artificial control, and can automatically realize the switching of two states completely according to the load condition.

(3) The speed stabilizing control during the conversion of the electric and regenerative braking states can be realized. The traditional brushless direct current motor control can only realize the speed stabilization control in an electric state or a regenerative braking state. The two states are independently operated, and the speed stabilizing control during the transition of the two states of the electric regenerative braking can not be realized. The method provided by the invention can realize closed-loop control of the rotating speed during transition of two states.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.