阅读说明：本技术 控制系统、控制方法以及带有步进电机的冷媒阀 (Control system, control method and refrigerant valve with stepping motor ) 是由 不公告发明人 于 2018-08-30 设计创作，主要内容包括：一种控制系统、控制方法以及带有步进电机的冷媒阀,控制系统包括电源模块、温度感应模块和微控制器,温度感应模块检测步进电机所处环境实时温度并生成实时温度信号,实时温度信号输出至微控制器；电源模块输出实时电源信号至微控制器；微控制器根据实时温度信号获取步进电机在启动阶段对应的相电压,微控制器根据相电压与步进电机在启动阶段对应的实时电源信号获取驱动步进电机转动的PWM信号的占空比,并根据占空比控制步进电机转动。这样,微控制器对步进电机启动阶段的控制过程得到了温度补偿与电源电压补偿,为实现步进电机在不同温度和不同电源电压下恒力矩启动提供了条件。(A control system, a control method and a refrigerant valve with a stepping motor are provided, wherein the control system comprises a power module, a temperature sensing module and a microcontroller, the temperature sensing module detects the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the microcontroller; the power supply module outputs a real-time power supply signal to the microcontroller; the microcontroller acquires phase voltage corresponding to the stepping motor in a starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and a real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio. Therefore, the microcontroller obtains temperature compensation and power supply voltage compensation for the control process of the step motor in the starting stage, and conditions are provided for realizing the constant torque starting of the step motor at different temperatures and different power supply voltages.)

1. A control system capable of controlling a stepper motor, the control system comprising:

the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end;

the temperature sensing module detects the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end;

the power supply module outputs a real-time power supply signal to a real-time power supply signal input end of the microcontroller through the real-time power supply signal output end; the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio.

2. The control system of claim 1, further comprising:

the microcontroller comprises an instruction signal output end, the driving signal control module comprises an instruction signal input end and a pre-driving signal output end, the digital-to-analog conversion module comprises a pre-driving signal input end and a driving signal output end, and the H-bridge driving module comprises a driving signal input end;

the microcontroller obtains an instruction signal according to the duty ratio and outputs the instruction signal to an instruction signal input end of the driving signal control module through the instruction signal output end, the driving signal control module outputs a PWM signal in a digital signal form to a pre-driving signal input end of the digital-to-analog conversion module through the pre-driving signal output end according to the instruction signal, the digital-to-analog conversion module converts the PWM signal in the digital signal form into a PWM signal in an analog signal form and outputs the PWM signal in the analog signal form to a driving signal input end of the H-bridge driving module through the driving signal output end, and the H-bridge driving module controls the stepping motor to rotate according to the PWM signal in the analog signal form.

3. A control method capable of controlling a stepping motor, characterized by comprising:

the temperature sensing module detects the real-time temperature of the environment where the stepping motor is located to generate a real-time temperature signal and outputs the real-time temperature signal to the microcontroller;

the power supply module outputs a real-time power supply signal to the microcontroller;

the microcontroller acquires a corresponding phase voltage of the stepping motor in a starting stage according to the real-time temperature signal;

and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the real-time power supply signal corresponding to the phase voltage and the starting stage of the stepping motor, and controls the stepping motor to rotate according to the duty ratio.

4. The control method according to claim 3, wherein the stepping motor comprises a coil, and the microcontroller acquires the corresponding phase voltage of the stepping motor in a starting stage according to the real-time temperature signal, and comprises the following steps:

the microcontroller acquires a real-time equivalent resistance value corresponding to the stepping motor according to the real-time temperature signal;

the microcontroller acquires a corresponding phase voltage of the stepping motor in a starting stage according to the real-time equivalent resistance value and the real-time current flowing through the stepping motor coil;

wherein the phase voltage is equal to the product of the real-time equivalent resistance value and the real-time current.

5. The control method according to claim 3, wherein the stepping motor comprises a coil, and the microcontroller acquires the corresponding phase voltage of the stepping motor in a starting stage according to the real-time temperature signal, and comprises the following steps:

the microcontroller acquires a real-time equivalent resistance value corresponding to the stepping motor according to the real-time temperature signal;

the microcontroller acquires real-time induced electromotive force corresponding to the stepping motor;

the microcontroller acquires a corresponding phase voltage of the stepping motor in a starting stage according to the real-time equivalent resistance value, the real-time current flowing through a coil of the stepping motor and the real-time induced electromotive force;

and the phase voltage is equal to the sum of the product of the real-time equivalent resistance value and the real-time current and the real-time induced electromotive force.

6. The control method of claim 5, wherein the step of obtaining the real-time induced electromotive force corresponding to the stepping motor by the microcontroller comprises:

the microcontroller acquires the real-time rotating speed of the stepping motor according to the real-time PWM signal output to the stepping motor;

and the microcontroller acquires the real-time induced electromotive force corresponding to the stepping motor according to the real-time rotating speed of the stepping motor.

7. The control method according to claim 4 or 5, wherein the stepping motor is driven by an H-bridge driving module, the H-bridge driving module comprises a set thin film transistor, and the real-time equivalent resistance value corresponding to the stepping motor is equal to the sum of the real-time equivalent resistance value of a coil of the stepping motor and the real-time equivalent resistance value of the set thin film transistor in the H-bridge driving module for driving the stepping motor to rotate.

8. The control method according to claim 4 or 5, characterized by, before obtaining the corresponding phase voltage of the stepper motor in the start-up phase, further comprising:

the microcontroller sets the current flowing through the coil of the stepping motor in a starting stage according to the set current in micro steps; the set current meets a continuous current curve, and the current flowing through the coil of the stepping motor in the starting stage meets an equivalent discrete current curve corresponding to the set current.

9. The control method according to claim 3, before the microcontroller obtains the phase voltage corresponding to the stepping motor in the starting phase according to the real-time temperature signal, further comprising:

the microcontroller controls the stepping motor to start in a variable speed mode, and the rotating speed of the stepping motor is gradually increased in the starting stage.

10. The utility model provides a refrigerant valve with step motor, includes stator module, rotor subassembly and circuit board subassembly, stator module includes the coil, the rotor subassembly includes the permanent magnet, the coil with circuit board subassembly electricity is connected, the coil generates the excitation magnetic field after circular telegram, the rotor subassembly rotates in the excitation magnetic field, its characterized in that, circuit board subassembly integration has step motor's control system, step motor's control system includes:

the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end;

the temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end;

the power supply module outputs a real-time power supply signal to a real-time power supply signal input end of the microcontroller through the real-time power supply signal output end;

the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio.

Technical Field

The embodiment of the invention relates to the technical field of control, in particular to a control system, a control method and a refrigerant valve with a stepping motor.

Background

When a system integrated with a stepping motor requires a wide working environment temperature range and a wide working power supply voltage range, the working environment temperature of the stepping motor changes greatly, and the working power supply voltage of the stepping motor changes greatly. For example, the coil in the stepping motor may be formed by winding a copper enameled wire, the temperature coefficient of resistance of copper is 0.0043, and when the external environment temperature changes by 100 ℃, the resistance value of the coil of the stepping motor changes by up to 43%, i.e., the resistance value of the coil of the stepping motor is greatly affected by the temperature change.

The starting of the stepping motor under the condition of lower environmental temperature can lead to the resistance value of a coil in the stepping motor to be smaller, the starting current of the stepping motor is overlarge, the overcurrent protection device is triggered, and then the stepping motor is stopped. The starting of the stepping motor under the condition of higher temperature can lead to the resistance of a coil in the stepping motor to be larger, the starting current of the stepping motor is too small, the moment of the starting stage of the stepping motor is insufficient, and similarly, the starting current of the stepping motor is too small due to the too small working power supply voltage of the stepping motor, and the moment of the starting stage of the stepping motor is insufficient. At present, the actual current flowing through the stepping motor can be collected and compared with the target current, and the output state of the microcontroller is controlled to achieve the purpose of controlling the current flowing through the stepping motor, but the cost of a stepping motor control system is increased by adopting a comparator circuit.

Disclosure of Invention

In view of this, embodiments of the present invention provide a control system, a control method, and a refrigerant valve with a stepping motor, where a microcontroller obtains temperature compensation and power supply voltage compensation for a control process of a start stage of the stepping motor, so as to provide conditions for realizing constant torque start of the stepping motor under different temperatures and different power supply voltages, improve a problem that a running state of the start stage of the stepping motor is seriously affected by temperature change of an environment where the stepping motor is located and power supply voltage change provided by a power supply module, avoid using devices such as a comparator, and reduce cost of the control system.

In a first aspect, an embodiment of the present invention provides a control system, capable of controlling a stepping motor, where the control system includes:

the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end;

the temperature sensing module detects the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end;

the power supply module outputs a real-time power supply signal to a real-time power supply signal input end of the microcontroller through the real-time power supply signal output end; the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio.

In a second aspect, an embodiment of the present invention further provides a control method, capable of controlling a stepping motor, where the control method includes:

the temperature sensing module detects the real-time temperature of the environment where the stepping motor is located to generate a real-time temperature signal and outputs the real-time temperature signal to the microcontroller;

the power supply module outputs a real-time power supply signal to the microcontroller;

the microcontroller acquires a corresponding phase voltage of the stepping motor in a starting stage according to the real-time temperature signal;

and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the real-time power supply signal corresponding to the phase voltage and the starting stage of the stepping motor, and controls the stepping motor to rotate according to the duty ratio.

In a third aspect, an embodiment of the present invention further provides a refrigerant valve with a stepper motor, including a stator assembly, a rotor assembly, and a circuit board assembly, where the stator assembly includes a coil, the rotor assembly includes a permanent magnet, the coil is electrically connected to the circuit board assembly, the coil generates an excitation magnetic field after being energized, the rotor assembly rotates in the excitation magnetic field, the circuit board assembly is integrated with a control system of the stepper motor, and the control system of the stepper motor includes:

the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end;

the temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end;

the power supply module outputs a real-time power supply signal to a real-time power supply signal input end of the microcontroller through the real-time power supply signal output end;

the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio.

The embodiment of the invention provides a control system, a control method and a refrigerant valve with a stepping motor. The temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end, the power supply module outputs a real-time power supply signal to the real-time power supply signal input end of the microcontroller through the real-time power supply signal output end, the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the starting stage of the. Therefore, the microcontroller acquires the phase voltage of the starting stage of the stepping motor according to the real-time temperature of the environment where the stepping motor is located and drives the stepping motor to rotate according to the phase voltage of the stepping motor and the real-time power supply signal corresponding to the starting stage of the stepping motor, the microcontroller obtains temperature compensation and power supply voltage compensation for the control process of the starting stage of the stepping motor, conditions are provided for realizing that the stepping motor can be started under the conditions of different temperatures and different power supply voltages, the problem that the running state of the starting stage of the stepping motor is seriously influenced by the temperature change of the environment where the stepping motor is located and the power supply voltage change provided by the power supply module is solved, devices such as a comparator are avoided, and the cost of the control system is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present invention, the drawings needed to be used in the description of the embodiments or the background art will be briefly introduced below, and it is obvious that the drawings in the following description are schematic diagrams of some embodiments of the present invention, and for those skilled in the art, other solutions can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a control system according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an H-bridge driving module according to an embodiment of the present invention;

fig. 3 is a schematic flow chart of a control method according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a refrigerant valve with a stepping motor according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described through embodiments with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. 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 embodiment of the invention provides a control system which can control a stepping motor, and the control system comprises a power supply module, a temperature sensing module and a microcontroller, wherein the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end. The temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end, and the power supply module outputs a real-time power supply signal to the real-time power supply signal input end of the microcontroller through the real-time power supply signal output end. The microcontroller acquires phase voltage corresponding to the starting stage of the stepping motor according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and a real-time power signal corresponding to the starting stage of the stepping motor and controls the stepping motor to rotate according to the duty ratio.

The control system provided by the embodiment of the invention comprises a power supply module, a temperature sensing module and a microcontroller, wherein the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end. The temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end, the power supply module outputs a real-time power supply signal to the real-time power supply signal input end of the microcontroller through the real-time power supply signal output end, the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the starting stage of the. Therefore, the microcontroller acquires the phase voltage of the starting stage of the stepping motor according to the real-time temperature of the environment where the stepping motor is located and drives the stepping motor to rotate according to the phase voltage of the stepping motor and the real-time power supply signal corresponding to the starting stage of the stepping motor, the microcontroller obtains temperature compensation and power supply voltage compensation for the control process of the starting stage of the stepping motor, conditions are provided for realizing that the stepping motor can be started under the conditions of different temperatures and different power supply voltages, the problem that the running state of the starting stage of the stepping motor is seriously influenced by the temperature change of the environment where the stepping motor is located and the power supply voltage change provided by the power supply module is solved, devices such as a comparator are avoided, and the cost of the control system is reduced.

The above is the core idea of the present invention, and the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the present invention.

Fig. 1 is a schematic structural diagram of a control system according to an embodiment of the present invention. As shown in fig. 1, the control system is used for controlling the stepping motor, the control system includes a power module 1, a temperature sensing module 2 and a microcontroller 3, the temperature sensing module 2 includes a real-time temperature signal output end a, the power module 1 includes a real-time power signal output end B, the microcontroller 3 includes a real-time temperature signal input end C1 and a real-time power signal input end C2, the real-time temperature signal output end a is electrically connected with the real-time temperature signal input end C1, and the real-time power signal output end B is electrically connected with the real-time power signal input end C2.

The temperature sensing module 2 detects the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end C1 of the microcontroller 3 through the real-time temperature signal output end a. The power module 1 outputs a real-time power signal to a real-time power signal input end C2 of the microcontroller 3 through a real-time power signal output end B, the microcontroller 3 acquires a phase voltage corresponding to the step motor in a starting stage according to the real-time temperature signal, and the microcontroller 3 acquires a duty ratio of a PWM signal for driving the step motor to rotate according to the phase voltage and the real-time power signal corresponding to the step motor starting stage and controls the step motor to rotate according to the duty ratio.

As shown in fig. 1, the control system may further include a driving signal control module 4, a digital-to-analog conversion module 5 and an H-bridge driving module 6, the microcontroller 3 includes a command signal output terminal C3, the driving signal control module 4 includes a command signal input terminal D1 and a pre-driving signal output terminal D2, the digital-to-analog conversion module 5 includes a pre-driving signal input terminal E1 and a driving signal output terminal E2, the H-bridge driving module 6 includes a driving signal input terminal F1, the command signal output terminal C3 is electrically connected to the command signal input terminal D1, the pre-driving signal output terminal D2 is electrically connected to the pre-driving signal input terminal E1, and the driving signal output terminal E2 is electrically connected to the driving signal input terminal.

After the microcontroller 3 obtains the duty ratio of the PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal, the microcontroller 3 obtains the instruction signal according to the duty ratio of the obtained PWM signal and outputs the instruction signal to the instruction signal input end D1 of the driving signal control module 4 through the instruction signal output end C3, the driving signal control module 4 converts the instruction signal containing the PWM signal duty ratio information into the PWM signal in the form of digital signal corresponding to the duty ratio, and outputs the PWM signal in the form of digital signal to the pre-driving signal input terminal E1 of the digital-to-analog conversion module 5 through the pre-driving signal output terminal D2, the digital-to-analog conversion module 5 converts the PWM signal in the form of digital signal into the PWM signal in the form of analog signal and outputs the PWM signal in the form of analog signal to the driving signal input terminal F1 of the H-bridge driving module 6 through the driving signal output terminal E2, and the H-bridge driving module 6 controls the stepping motor to rotate according to the PWM signal in the form of analog signal.

Fig. 2 is a schematic structural diagram of an H-bridge driving module according to an embodiment of the present invention. As shown in fig. 2, the H-bridge driving module 6 may include a first transistor T1, a second transistor T2, a third transistor T3 and a fourth transistor T4, and the first transistor T1 to the fourth transistor T4 and the trace connecting the stepping motor coil 7 constitute an H-type architecture of the H-bridge driving module 6.

With reference to fig. 1 and fig. 2, the digital-to-analog conversion module 5 may be configured to output four paths of PWM signals in the form of analog signals, where the four paths of PWM signals are respectively output to the control terminals a of the first transistor T1 to the fourth transistor T4. For example, the first transistor T1 and the fourth transistor T4 may be controlled to be turned on, the second transistor T2 and the third transistor T3 may be controlled to be turned off, the current direction in the coil is, for example, I1, and the rotor 8 of the stepping motor may be controlled to rotate counterclockwise by the current in the coil. The first transistor T1 and the fourth transistor T4 can be controlled to be turned off, the second transistor T2 and the third transistor T3 can be controlled to be turned off, the current direction in the coil is, for example, I2, and the rotor 8 of the stepping motor rotates clockwise under the action of the current in the coil. The control of the rotational direction of the rotor 8 in the stepping motor is achieved by controlling the switching states of the first to fourth transistors T1 to T4. The current flowing through the coil of the stepping motor can be adjusted by adjusting the duty ratio of the corresponding PWM signal, so that the rotating speed of the rotor 8 in the stepping motor is adjusted, and the rotating speed of the stepping motor is controlled.

The duty ratio of the PWM signal output to the H-bridge driving module 6 is consistent with the duty ratio of the PWM signal acquired by the microcontroller 3, the duty ratio of the PWM signal acquired by the microcontroller 3 is acquired according to the phase voltage of the stepping motor in the starting stage calculated by the real-time temperature signal and the real-time power supply signal applied to the stepping motor, and accordingly the microcontroller 3 obtains temperature compensation and power supply voltage compensation for the control process of the stepping motor in the starting stage, conditions are provided for realizing that the stepping motor can be started under the conditions of different temperatures and different power supply voltages by constant torque, and the problem that the running state of the stepping motor in the starting stage is seriously influenced by the temperature change of the environment where the stepping motor is located and the working power supply voltage change of the stepping motor is solved.

It should be noted that fig. 1 only exemplarily uses one port to represent each signal terminal, and does not represent the actual number of each signal terminal, and the number of each signal terminal may be set according to specific requirements. In addition, fig. 2 only exemplarily shows one H-bridge driving module 6 and one set of coils 7 of the stepping motor, and the number of H-bridge driving modules 6 and the number of coils 7 of the stepping motor in the control system are not limited in the embodiment of the present invention, and the number of H-bridge driving modules 6 and the number of coils 7 of the stepping motor in the control system may be set according to specific requirements.

On the basis of the foregoing embodiment, an embodiment of the present invention further provides a control method, which can control a stepping motor, can be applied to a scenario where the stepping motor needs to be controlled, and can be executed by a control system for controlling the stepping motor in the foregoing embodiment, where fig. 3 is a flowchart of the control method provided in the embodiment of the present invention, and as shown in fig. 3, the control method includes:

s101, detecting the real-time temperature of the environment where the stepping motor is located by the temperature sensing module to generate a real-time temperature signal and outputting the real-time temperature signal to the microcontroller.

With reference to fig. 1 to 3, the temperature sensing module 2 may be a temperature sensor, the temperature sensing module 2 detects a real-time temperature of an environment where the stepping motor is located, generates a real-time temperature signal according to the detected real-time temperature, and outputs the real-time temperature signal to the microcontroller 3, and the real-time temperature signal may be output to a real-time temperature signal input terminal C1 of the microcontroller 3 through a real-time temperature signal output terminal a of the temperature sensing module 2.

And S102, the power supply module outputs a real-time power supply signal to the microcontroller.

S103, the microcontroller acquires the corresponding phase voltage of the stepping motor in the starting stage according to the real-time temperature signal.

Referring to fig. 1 to 3, a method for obtaining a phase voltage corresponding to a step motor in a start phase includes obtaining, by a microcontroller 3, a real-time equivalent resistance value corresponding to the step motor according to a real-time temperature signal. Illustratively, the stepping motor includes a coil 7, the stepping motor is driven by an H-bridge driving module 6, the H-bridge driving module 6 includes a set thin film transistor, a real-time equivalent resistance value corresponding to the stepping motor may be equal to a sum of the real-time equivalent resistance value of the coil 7 of the stepping motor and a real-time equivalent resistance value of a set thin film transistor in the H-bridge driving module 6, the set thin film transistor may be a thin film transistor in an on state in the H-bridge driving module 6, the set thin film transistor may be a first transistor T1 and a fourth transistor T4, the set thin film transistor may also be a second transistor T2 and a third transistor T3, the thin film transistor includes a gate structure, a source structure, a drain structure and an active layer structure, and an equivalent internal resistance value of the thin film transistor may be approximately equal to a resistance value of the active layer.

When the first transistor T1 and the fourth transistor T4 in the H-bridge driving module 6 are turned on and the second transistor T2 and the third transistor T3 are turned off, the real-time equivalent resistance value corresponding to the stepping motor is equal to the sum of the real-time equivalent resistance value of the coil 7 of the stepping motor, the real-time resistance value of the active layer in the first transistor T1, and the real-time resistance value of the active layer in the fourth transistor T4. When the second transistor T2 and the third transistor T3 in the H-bridge driving module 6 are turned on and the first transistor T1 and the fourth transistor T4 are turned off, the real-time equivalent resistance value corresponding to the stepping motor is equal to the sum of the real-time equivalent resistance value of the coil 7 of the stepping motor, the real-time resistance value of the active layer in the second transistor T2, and the real-time resistance value of the active layer in the third transistor T3.

The real-time equivalent resistance value of the coil in the stepping motor and the real-time equivalent resistance value of the set thin film transistor can change along with the change of the temperature of the environment where the stepping motor is located, after the microcontroller 3 acquires the real-time temperature signal, the real-time equivalent resistance value of the coil in the stepping motor and the real-time equivalent resistance value of the set thin film transistor can be acquired according to the resistance temperature coefficient of the coil of the stepping motor and the resistance temperature coefficient of the set thin film transistor, compared with the prior art that the phase voltage of the stepping motor in the starting stage is acquired by adopting the fixed equivalent resistance value corresponding to the stepping motor, the temperature compensation of the equivalent resistance value corresponding to the stepping motor is realized, and the temperature compensation of the control process in the starting stage of the.

With reference to fig. 1 to 3, the microcontroller 3 obtains the phase voltage corresponding to the stepping motor at the starting stage according to the real-time equivalent resistance value of the stepping motor and the real-time current flowing through the coil of the stepping motor, where the phase voltage of the stepping motor is the voltage difference applied to the two ends d1 and d2 of the coil of the stepping motor; and the phase voltage of the stepping motor is equal to the product of the real-time equivalent resistance value of the stepping motor and the real-time current flowing through the coil of the stepping motor. The real-time equivalent resistance value of the stepping motor coil can be set to be R_windings(T) setting the real-time equivalent resistance value of the thin film transistor to R_FET(T) the real-time current flowing through the stepping motor coil is I_MotorT is the temperature of the coil of the stepping motor, approximately equal to the temperature of the environment in which the stepping motor is located,the corresponding phase voltage V of the stepping motor in the starting stage_Motor(T) satisfies the following formula:

V_Motor(T)＝I_Motor·[R_windings(T)+R_FET(T)]

accordingly, the microcontroller 3 obtains the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and realizes the temperature compensation of the equivalent resistance value corresponding to the stepping motor so as to realize the temperature compensation of the control process in the starting stage of the stepping motor.

Referring to fig. 1 to 3, in another method for obtaining the phase voltage corresponding to the step motor in the starting stage, the microcontroller 3 obtains the real-time equivalent resistance value corresponding to the step motor according to the real-time temperature signal. The real-time equivalent resistance value corresponding to the stepping motor is defined according to the above description, which is not repeated herein, and compared with the prior art that the phase voltage of the stepping motor in the starting stage is obtained by using the fixed equivalent resistance value corresponding to the stepping motor, the temperature compensation of the equivalent resistance value corresponding to the stepping motor is also realized, so as to realize the temperature compensation of the control process in the starting stage of the stepping motor.

The microcontroller 3 obtains the real-time induced electromotive force corresponding to the stepping motor. Illustratively, the microcontroller 3 obtains the real-time rotating speed of the stepping motor according to the real-time PWM signal output to the stepping motor, the induced electromotive force of the stepping motor is the induced electromotive force generated when the rotor 8 of the stepping motor rotates to cut the magnetic induction line, the stepping motor is open-loop control, the microcontroller 3 can directly calculate and obtain the real-time rotating speed of the stepping motor according to the real-time PWM signal output to the stepping motor, and the microcontroller 3 obtains the real-time induced electromotive force corresponding to the stepping motor according to the real-time rotating speed of the stepping motor. The real-time rotating speed of the stepping motor can be set to be V, the reverse constant is k, and then the real-time induced electromotive force B corresponding to the stepping motor_emfThe following formula is satisfied:

B_emf＝k·V

illustratively, before the microcontroller 3 acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, the microcontroller 3 controls the stepping motor to start at a variable speed, and the rotating speed of the stepping motor is gradually increased in the starting stage. Under the condition of higher requirement on the torque of the stepping motor, in order to avoid the step-out phenomenon of the stepping motor, the stepping motor can be controlled to start at a variable speed, namely, the rotating speed of the stepping motor in the starting stage is controlled to be faster and faster, and the induced electromotive force corresponding to the stepping motor can also be linearly increased along with the rotating speed of the stepping motor.

The microcontroller 3 acquires a corresponding phase voltage of the stepping motor in a starting stage according to the real-time equivalent resistance value of the stepping motor, the real-time current flowing through a coil of the stepping motor and the real-time induced electromotive force; and the phase voltage of the stepping motor is equal to the sum of the product of the real-time equivalent resistance value of the stepping motor and the real-time current flowing through the stepping motor coil and the real-time induced electromotive force. The real-time equivalent resistance value of the stepping motor coil can be set to be R_windings(T) setting the real-time equivalent resistance value of the thin film transistor to R_FET(T) the real-time current flowing through the stepping motor coil is I_MotorAnd T is the temperature of the coil of the stepping motor and is approximately equal to the temperature of the environment where the stepping motor is located, the corresponding phase voltage V of the stepping motor in the starting stage_Motor(T) satisfies the following formula

V_Motor(T)＝I_Motor·[R_windings(T)+R_FET(T)]+B_emf

Accordingly, the microcontroller 3 obtains the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, and realizes the temperature compensation of the equivalent resistance value corresponding to the stepping motor so as to realize the temperature compensation of the control process in the starting stage of the stepping motor. In addition, the real-time induced electromotive force corresponding to the stepping motor is considered in the acquisition of the phase voltage corresponding to the stepping motor in the starting stage, so that the accuracy of the phase voltage of the stepping motor in the starting stage is improved, the accuracy of the duty ratio of the PWM signal calculated according to the phase voltage of the stepping motor in the starting stage is further improved, and the accuracy of the control process of the stepping motor is improved.

For the two methods for obtaining the phase voltage corresponding to the step motor in the starting stage, before obtaining the phase voltage corresponding to the step motor in the starting stage, the microcontroller 3 may set the current flowing through the coil of the step motor in the starting stage according to the set current in micro steps; the set current satisfies a continuous current curve, and the current flowing through the coil of the stepping motor at the starting stage satisfies an equivalent discrete current curve corresponding to the set current. For example, the set current is a current flowing through a coil of the stepping motor before micro-step setting is performed, the set current may satisfy a sine function curve, that is, a continuous current curve, and the set current may be micro-step set, and the micro-step setting may be discrete processing of the set current, that is, the current flowing through the coil of the stepping motor at the start stage after the micro-step setting satisfies an equivalent discrete current curve corresponding to the set current, for example, the sine function curve is discrete processed by using a certain interval, so that the stepping motor is driven to rotate by stepping, and the stepping motor is started according to the set current waveform.

And S104, the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the starting stage of the stepping motor, and controls the stepping motor to rotate according to the duty ratio.

Referring to fig. 1 to 3, the microcontroller 3 obtains the duty ratio of the PWM signal for driving the stepping motor to rotate according to the phase voltage corresponding to the starting phase of the stepping motor and the real-time power signal corresponding to the starting phase of the stepping motor, and may set the phase voltage corresponding to the starting phase of the stepping motor to be V_Motor(T), the real-time power supply signal corresponding to the starting stage of the stepping motor is V_supplyAnd the duty ratio D of PWM signal for driving step motor to rotate_pwmThe following calculation formula is satisfied:

the microcontroller 3 obtains the phase voltage of the starting stage of the stepping motor according to the real-time temperature of the environment where the stepping motor is located and drives the stepping motor to rotate according to the phase voltage of the stepping motor and the real-time power supply signal corresponding to the starting stage of the stepping motor, and the microcontroller 3 obtains temperature compensation and power supply voltage compensation for the control process of the starting stage of the stepping motor. The microcontroller 3 controls the stepping motor to rotate according to the calculated duty ratio of the PWM signal, as shown in fig. 2, the microcontroller 3 obtains an instruction signal according to the calculated duty ratio of the PWM signal and outputs the instruction signal to the driving signal control module 4, the driving signal control module 4 converts the instruction signal containing the PWM signal duty ratio information into a PWM signal in a digital signal form corresponding to the duty ratio and outputs the PWM signal to the digital-to-analog conversion module 5, the digital-to-analog conversion module 5 converts the PWM signal in the digital signal form into a PWM signal in an analog signal form and outputs the PWM signal to the H-bridge driving module 6, and the H-bridge driving module 6 controls the stepping motor to rotate according to the PWM signal in the analog signal form.

The control system provided by the embodiment of the invention comprises a power supply module, a temperature sensing module and a microcontroller, wherein the temperature sensing module comprises a real-time temperature signal output end, the power supply module comprises a real-time power supply signal output end, and the microcontroller comprises a real-time temperature signal input end and a real-time power supply signal input end. The temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end, the power supply module outputs a real-time power supply signal to the real-time power supply signal input end of the microcontroller through the real-time power supply signal output end, the microcontroller acquires the phase voltage corresponding to the stepping motor in the starting stage according to the real-time temperature signal, the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and the real-time power supply signal corresponding to the starting stage of the. Therefore, the microcontroller acquires the phase voltage of the starting stage of the stepping motor according to the real-time temperature of the environment where the stepping motor is located and drives the stepping motor to rotate according to the phase voltage of the stepping motor and the real-time power supply signal corresponding to the starting stage of the stepping motor, the microcontroller obtains temperature compensation and power supply voltage compensation for the control process of the starting stage of the stepping motor, conditions are provided for realizing that the stepping motor can be started under the conditions of different temperatures and different power supply voltages, the problem that the running state of the starting stage of the stepping motor is seriously influenced by the temperature change of the environment where the stepping motor is located and the power supply voltage change provided by the power supply module is solved, devices such as a comparator are avoided, and the cost of the control system is reduced.

The embodiment of the invention also provides a refrigerant valve with a stepping motor, and fig. 4 is a schematic structural diagram of the refrigerant valve with the stepping motor provided by the embodiment of the invention. As shown in fig. 4, the refrigerant valve 100 includes a housing 60, a stator assembly 601, a rotor assembly 602, and a circuit board assembly 90, the circuit board assembly 90 is disposed in an inner cavity formed by the housing 60, stator module 601 sets up in rotor module 602's periphery, rotor module 602 and stator module 601 constitute the step motor in refrigerant valve 100, stator module 601 includes the coil, rotor module 602 includes the permanent magnet, coil 5 is connected with circuit board assembly 90 electricity, coil 5 produces the excitation magnetic field after circular telegram, rotor module 602 rotates in the excitation magnetic field, circuit board assembly 90 integrates step motor's control system, step motor's control system includes power module, temperature-sensing module and microcontroller, temperature-sensing module includes real-time temperature signal output, power module includes real-time power signal output, microcontroller includes real-time temperature signal input and real-time power signal input. The temperature sensing module acquires the real-time temperature of the environment where the stepping motor is located and generates a real-time temperature signal, and the real-time temperature signal is output to the real-time temperature signal input end of the microcontroller through the real-time temperature signal output end. The power supply module outputs a real-time power supply signal to a real-time power supply signal input end of the microcontroller through a real-time power supply signal output end. The microcontroller acquires phase voltage corresponding to the stepping motor in a starting stage according to the real-time temperature signal, and the microcontroller acquires the duty ratio of a PWM signal for driving the stepping motor to rotate according to the phase voltage and a real-time power supply signal corresponding to the stepping motor in the starting stage and controls the stepping motor to rotate according to the duty ratio. For example, the refrigerant valve with the stepping motor may be a four-way electronic water valve with a high requirement on the rotation torque. Since the control system of the stepping motor according to the above embodiment is integrated in the circuit board assembly 90, the control system of the stepping motor according to the above embodiment also has the beneficial effects, and details are not described here.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments illustrated herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.