WO2022062128A1

WO2022062128A1 - Control system and method for electronic expansion valve

Info

Publication number: WO2022062128A1
Application number: PCT/CN2020/128912
Authority: WO
Inventors: 闫冰; 范春丽; 何继富
Original assignee: 艾默生环境优化技术(苏州)有限公司
Priority date: 2020-09-28
Filing date: 2020-11-16
Publication date: 2022-03-31
Also published as: CN114278735B; CN114278735A

Abstract

A control system and method for an electronic expansion valve. An electronic expansion valve (10) comprises a valve component (11) and a motor (13, 110, 210, 310, 410). The valve component (11) comprises a valve body (11a) and a valve core (11b) that can move with respect to the valve body (11a); the motor (13, 110, 210, 310, 410) is configured to be capable of making the valve core (11b) move so as to turn on or off the electronic expansion valve (10). The control system comprises a power supply device (120, 220, 320, 420), the power supply device (120, 220, 320, 420) being configured to supply power for the motor (13, 110, 210, 310, 410); and a control device (130, 230, 330, 430). The modes in which the control device (130, 230, 330, 430) drives the motor (13, 110, 210, 310, 410) comprise a first mode and a second mode, wherein current required for driving the motor (13, 110, 210, 310, 410) in the first mode is less than current required for driving the motor (13, 110, 210, 310, 410) in the second mode. The control device (130, 230, 330, 430) is configured to selectively drive the motor (13, 110, 210, 310, 410) in the first mode or the second mode according to a preset motor driving association parameter when the electronic expansion valve (10) is started.

Description

Control system and control method for electronic expansion valve

This application claims the priority of the Chinese patent application with the application number 202011040478.9 and the invention-creation title "Control System and Control Method for Electronic Expansion Valves" filed with the China Patent Office on September 28, 2020. The entire contents of this patent application are incorporated herein by reference.

technical field

The present disclosure relates to a control system for an electronic expansion valve and a control method for the electronic expansion valve.

Background technique

The content in this section merely provides background information related to the present disclosure and may not constitute prior art.

An electronic expansion valve including a valve member and a stepper motor is known. The valve component includes a fixed valve body and a valve core that is movable relative to the valve body. When the stepping motor is driven by power supply, its rotor rotates relative to the stator, and then the rotor drives the valve core to move to open or close the electronic expansion valve.

DC power is usually provided to the stepper motor by means of a switching power supply and drives the stepper motor. At present, in order to achieve the purpose of precise control, a large current is often required to drive the stepping motor. However, in some cases, for example, when the input voltage of the switching power supply is too low or the ambient temperature is too low, the switching power supply may not be able to meet the current requirements of the stepper motor, or because the current requirements of the stepper motor are too high. Unable to output normally.

Therefore, there is a need in the art for a system and method that can safely and reliably control an electronic expansion valve.

SUMMARY OF THE INVENTION

An object of the present disclosure is to provide a system and method capable of safely and reliably controlling an electronic expansion valve.

Another object of the present disclosure is to provide a lower cost control system and control method for an electronic expansion valve.

According to one aspect of the present disclosure, a control system for an electronic expansion valve is provided. The electronic expansion valve includes a valve member including a valve body and a valve core movable relative to the valve body and a motor, the motor being configured to move the valve core to open or close the electronic expansion valve Expansion valve. The control system includes: a power supply device configured to provide power to the motor; and a control device, the control device driving the motor in a mode including a first mode and a second mode, wherein in all The current required to drive the motor in the first mode is less than the current required to drive the motor in the second mode. The control device is configured to selectively drive the motor in a first mode or a second mode according to preset motor drive-related parameters when the electronic expansion valve is activated.

The control system for an electronic expansion valve of the present application can selectively activate the electronic control valve according to parameters related to the operation or driving of the motor (for example, the input voltage of the power supply device, the ambient temperature, or the driving time of the motor, etc.). Either the first mode (eg, full-step drive with lower current requirements) or the second mode (eg, half-step drive with higher current requirements) drives the motor. In this way, it can not only solve the problem that the supply current is low and cannot be driven normally, but also realize high-precision control when the current demand is met.

In addition, the control system for an electronic expansion valve according to the present disclosure only needs to add a detection circuit including several resistances and detection devices, so the added cost is low, and the development period can be reduced.

In some embodiments, the preset motor drive-related parameters include an input voltage of the power supply device. The control system further includes a voltage detection device configured to detect an input voltage of the power supply device. The control device drives the motor in the first mode or the second mode according to the input voltage.

In some embodiments, the control device is configured to: when the detected input voltage is lower than a predetermined value of a first voltage, the control device drives the motor in the first mode; when the detected input voltage is higher than a first voltage When there are two predetermined voltage values, the control device drives the motor in the second mode, and the second predetermined voltage value is greater than the first predetermined voltage value; and when the detected input voltage is greater than or equal to the first voltage When the predetermined value is less than or equal to the predetermined value of the second voltage, the control device drives the motor in the current mode.

In some embodiments, the control system further includes a negative temperature coefficient resistor, and the negative temperature coefficient resistor is provided on the input side of the power supply device.

In some embodiments, the preset motor drive-related parameter includes an ambient temperature of the negative temperature coefficient resistor. The control system further includes a temperature detection device configured to detect an ambient temperature of the negative temperature coefficient resistor.

In some embodiments, the control device is configured to drive the motor in the first mode when the detected ambient temperature is lower than a first predetermined temperature value; when the detected ambient temperature is higher than the first temperature When there are two predetermined temperature values, the control device drives the motor in the second mode, and the second predetermined temperature value is greater than the first predetermined temperature value; and when the detected ambient temperature is greater than or equal to the first temperature When the predetermined value is less than or equal to the predetermined second temperature value, the control device drives the motor in the current mode.

In some embodiments, the preset motor driving related parameters include the input voltage of the power supply device and the ambient temperature of the negative temperature coefficient resistor. The control system further includes: a voltage detection device configured to detect an input voltage of the power supply device; and a temperature detection device configured to detect the negative temperature coefficient resistance ambient temperature.

In some embodiments, the control device is configured to drive in the first mode when the detected input voltage is lower than a first voltage predetermined value and the detected ambient temperature is lower than a first temperature predetermined value the motor; when the detected input voltage is higher than a second predetermined voltage value or the detected ambient temperature is higher than a second predetermined temperature value, the control device drives the motor in the second mode, wherein the first Two predetermined voltage values are greater than the first predetermined voltage value and the second predetermined temperature value is greater than the first predetermined temperature value; and when the detected input voltage is greater than or equal to the first predetermined voltage value but less than or equal to the first predetermined value When the voltage is two predetermined values and the detected ambient temperature is greater than or equal to the first predetermined temperature value but less than or equal to the second predetermined temperature value, the control device drives the motor in the current mode.

In some embodiments, the control system further includes a timer for measuring the drive time of the first mode. The control system is configured to select to drive the electric motor in the first mode upon actuation of the electronic expansion valve. The preset motor driving related parameter includes a driving time for driving the motor in the first mode. The second mode is switched when the drive time reaches a set time.

In some embodiments, the motor is a stepping motor, the power supply device is a switching power supply, the first mode is a full-step driving mode, and the second mode is a half-step driving mode.

According to one aspect of the present disclosure, a control method for an electronic expansion valve is provided. The electronic expansion valve includes a valve member including a valve body and a valve core movable relative to the valve body and a motor, the motor being configured to move the valve core to open or close the electronic expansion valve Expansion valve. The control method includes the steps of: acquiring parameters related to driving of the motor; supplying power to the motor through a power supply device to drive the motor, wherein driving in a first mode or a second mode is selected according to the parameters For the motor, the current required to drive the motor in the first mode is smaller than the current required to drive the motor in the second mode.

This control method has similar advantages to the control system described above.

In some embodiments, obtaining parameters related to driving of the motor includes detecting an input voltage of the power supply device, and selecting to drive the motor in the first mode or the second mode according to the detected input voltage .

In some embodiments, when the detected input voltage is lower than a predetermined value of a first voltage, the motor is selected to be driven in the first mode; when the detected input voltage is higher than a predetermined value of a second voltage, the motor is selected to be driven in the first mode. The motor is driven in a second mode, the predetermined second voltage value is greater than the predetermined first voltage value; and when the detected input voltage is greater than or equal to the predetermined predetermined value of the first voltage but less than or equal to the predetermined predetermined value of the second voltage , maintain the current mode to drive the motor.

In some embodiments, the control method further includes providing a negative temperature coefficient resistance on the input side of the power supply device.

In some embodiments, acquiring parameters related to driving of the motor includes detecting an ambient temperature of the negative temperature coefficient resistor, and selecting to drive the motor in the first mode or the second mode according to the detected ambient temperature described motor.

In some embodiments, the control method further includes: when the detected ambient temperature is lower than a predetermined first temperature value, selecting to drive the motor in the first mode; when the detected ambient temperature is higher than a predetermined second temperature When the detected ambient temperature is greater than or equal to the first temperature predetermined value but less than or equal to the When the predetermined second temperature value is reached, the current mode is maintained to drive the motor.

In some implementations, acquiring the parameters related to the driving of the motor includes detecting the input voltage of the power supply device, detecting the ambient temperature of the negative temperature coefficient resistor, and selecting the desired parameter according to the detected input voltage and ambient temperature. The first mode or the second mode drives the motor.

In some embodiments, the control method further comprises: selecting to drive the motor in the first mode when the detected input voltage is lower than a first voltage predetermined value and the detected ambient temperature is lower than a first temperature predetermined value ; when the detected input voltage is higher than a second predetermined voltage value or the detected ambient temperature is higher than a second predetermined temperature value, select to drive the motor in the second mode, wherein the second predetermined voltage value is greater than the predetermined value the first voltage predetermined value and the second temperature predetermined value are greater than the first temperature predetermined value; and when the detected input voltage is greater than or equal to the first voltage predetermined value but less than or equal to the second voltage predetermined value and the detection When the ambient temperature is greater than or equal to the first predetermined temperature value but less than or equal to the second predetermined temperature value, the current mode is maintained to drive the motor.

In some embodiments, selecting to drive the electric motor in the first mode when the electronic expansion valve is activated, obtaining a parameter related to the actuation of the electric motor includes measuring a drive time of the first mode, and the When the driving time reaches the set time, it switches to the second mode.

In some embodiments, the control method further includes: when starting to drive the motor, first determining whether the current mode is the first mode or the second mode.

Additional areas of application will become apparent from the descriptions provided herein. It should be understood that the specific examples and implementations described in this section are for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Description of drawings

The features and advantages of one or more embodiments of the present disclosure will become more readily understood from the following description with reference to the accompanying drawings, in which:

1 is a schematic cross-sectional view of an electronic expansion valve;

2 is a schematic functional block diagram of a control system for an electronic expansion valve according to a first embodiment of the present disclosure;

3 is a schematic flowchart of a control method of the control system of FIG. 2;

4 is a schematic functional block diagram of a control system for an electronic expansion valve according to a second embodiment of the present disclosure;

5 is a schematic flowchart of a control method of the control system of FIG. 4;

6 is a schematic functional block diagram of a control system for an electronic expansion valve according to a third embodiment of the present disclosure;

7 is a schematic flowchart of a control method of the control system of FIG. 6;

8 is a schematic functional block diagram of a control system for an electronic expansion valve according to a fourth embodiment of the present disclosure; and

FIG. 9 is a schematic flowchart of a control method of the control system of FIG. 8 .

It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

detailed description

Exemplary embodiments of the present application will now be described more fully with reference to the accompanying drawings.

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods in order to provide a thorough understanding of various embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The structure of the electronic expansion valve 10 will be described below with reference to FIG. 1 . As shown in FIG. 1 , the electronic expansion valve 10 includes a valve member 11 that communicates

fluid pipes

20 and 30 and a motor 13 that drives the valve member 11 to be in an open state or a closed state.

The valve member 11 includes a fixed valve body 11a and a valve body 11b movable with respect to the valve body 11a. A valve hole 12 is formed in the valve body 11a. When the spool 11b moves away from the valve hole 12, the electronic expansion valve 10 is opened to allow fluid to flow between the

fluid pipes

20 and 30; when the spool 11b moves toward the valve hole 12, the electronic expansion valve 10 is closed to prevent fluid from flowing in the fluid Flow between

pipes

20 and 30.

The motor 13 includes a fixed stator 13a and a rotor 13b movable relative to the stator 13a. The stator 13a is fixed to the valve body 11a, and the rotor 13b is coupled to the valve core 11b. The motor 13 is connected to a power supply unit (not shown) by a cable 40 . When the power supply device supplies power to the motor 13, current passes through the windings 14 of the stator 13a of the motor 13, thereby generating a magnetic field that causes the rotor 13b to rotate relative to the stator 13a. The rotation of the rotor 13b moves the spool 11b away from the valve hole 12 or toward the valve hole 12 to open or close the electronic expansion valve 10 .

The motor 13 may be, for example, a stepper motor. In order for the rotor 13b of the motor 13 to rotate continuously and smoothly, the stator must generate a continuous and average magnetic field. The strength and direction of the magnetic field of the stator 13a of the motor 13 are determined and proportional to the resultant current of the stator 13a. That is, as long as the current of the stator 13a of the motor 13 is controlled, the purpose of driving the motor 13 can be achieved.

The drive of stepper motor includes full-step drive and half-step drive. Full-step drive is less accurate and requires less current, while half-step drive is more accurate and requires more current. Usually, in order to achieve higher control accuracy, a half-step driving method is used to drive the stepping motor.

However, for example, when the input voltage of the power supply device is too low, the current demand of the stepping motor may not be met, or the current demand of the stepping motor may not be able to output normally. For example, in the case where a negative temperature coefficient (NTC) resistor is provided to suppress the surge current impact on the input terminal of the power supply device, when the ambient temperature is low, the resistance of the NTC resistor increases, resulting in the input terminal of the power supply device. Voltage drops. Therefore, the power supply device may not be able to meet the current requirement of the stepper motor, or the current requirement of the stepper motor may not be able to output normally.

The control system and control method for an electronic expansion valve according to the present disclosure can selectively activate the electronic expansion valve according to preset motor driving related parameters (for example, the input voltage of the power supply device, the ambient temperature, or the driving time of the motor, etc.). Safely and reliably driving the motor or driving the motor with high precision in a first mode (eg, full-step drive) or a second mode (eg, half-step drive), where driving the motor in the first mode requires The current is less than the current required to drive the motor in the second mode. In this way, it can not only solve the problem that the supply current is low and cannot be driven normally, but also realize high-precision control when the current demand is met.

A control system and a control method for an electronic expansion valve according to various embodiments of the present disclosure will be described below with reference to the accompanying drawings.

2 is a schematic functional block diagram of a control system for an electronic expansion valve according to a first embodiment of the present disclosure. As shown in FIG. 2 , the control system according to the first embodiment includes: a switching power supply 120 for supplying DC power to the stepping motor 110 of the electronic expansion valve; a voltage detection device 140 for detecting the input voltage of the input terminal of the switching power supply 120 ; And the control device 130 for driving the stepping motor 110 in a full-step driving mode or a half-step driving mode according to the detected input voltage. The current required to drive the stepper motor 110 in the full-step drive mode is less than the current required to drive the stepper motor 110 in the half-step drive mode.

The switching power supply 120 is an example of the above-mentioned power supply device. If the input voltage of the switching power supply 120 is low, the full-step driving mode can be selected to drive the stepping motor 110 . At this time, even if the current supplied to the stepping motor 110 is reduced due to the lower input voltage, the current requirement can be satisfied because the current required for the full-step driving mode is smaller. If the input voltage of the switching power supply 120 is high, the half-step driving mode can be selected to achieve precise operation of the electronic expansion valve. At this time, since the current supplied to the stepping motor 110 can meet the requirement of half-step driving, a precise driving mode can be selected to achieve better operation effect of the electronic expansion valve.

FIG. 3 is a schematic flowchart of a control method of the control system of FIG. 2 . The control method of the control system of FIG. 2 will be described below with reference to FIG. 3 .

As shown in FIG. 3 , the electronic expansion valve is activated in step S00 , ie, the electronic expansion valve (specifically, the stepper motor 110 ) is energized, and the electronic expansion valve is reset to subsequently drive the stepper motor 110 and move the spool. After the electronic expansion valve is activated, driving of the stepping motor 110 is started at step S01. Next, at step S02, it is determined whether the current driving mode is the full-step driving mode.

If it is determined in step S02 that the current driving mode is not the full-step driving mode (ie, the half-step driving mode), then proceed to step S110 to compare the input voltage U detected by the voltage detection device 140 with the first predetermined voltage value U1. The first predetermined voltage value U1 can be set according to the requirements of half-step driving and full-step driving of the stepping motor 110 . In other words, when the input voltage is lower than the predetermined value of the first voltage, the requirement of half-step driving cannot be satisfied.

When it is determined in step S110 that the input voltage U is less than the predetermined first voltage value U1, since it cannot meet the requirement of half-step driving, the current driving mode (half-step driving mode) is switched to full-step driving mode in step S111. When the input voltage U is not less than the predetermined value U1 of the first voltage, the current driving mode is maintained in the half-step driving mode, see step S122.

If it is determined in step S02 that the current driving mode is the full-step driving mode, then proceed to step S120 to compare the input voltage U detected by the voltage detection device 140 with the second predetermined voltage value U2, wherein the second predetermined voltage value U2 is greater than The first voltage is a predetermined value U1. Similarly, the second predetermined voltage value U2 can be set according to the requirements of half-step driving and full-step driving of the stepping motor 110 . In other words, when the input voltage is higher than the predetermined value of the second voltage, stable driving of the stepping motor in the half-step driving mode can be ensured.

When it is determined in step S120 that the input voltage U is greater than the predetermined value U2 of the second voltage, since it can fully meet the requirements of half-step driving, the current driving mode (full-step driving mode) is switched to half-step driving mode in step S121 . When the input voltage U is not higher than the predetermined second voltage value U2, the current driving mode is maintained in the full-step driving mode, see step S112.

The driving manner in steps S112 and S122 may continue until the driving of the electronic expansion valve ends (see step S10).

The control system and control method for an electronic expansion valve according to the first embodiment actively detect the input voltage of the input terminal of the switching power supply when the electronic expansion valve is activated, and can determine the driving mode of the stepping motor according to the detected input voltage. That is, when the input voltage is low, the stepping motor can be driven in a full-step driving manner, thereby avoiding the situation that the current cannot be driven normally due to insufficient current. When the input voltage is high, the stepping motor can be driven in a half-step driving manner, thereby realizing high-precision operation.

4 is a schematic functional block diagram of a control system for an electronic expansion valve according to a second embodiment of the present disclosure. As shown in FIG. 4 , the control system according to the second embodiment includes: a switching power supply 220 for supplying DC power to the stepping motor 210 of the electronic expansion valve; a negative temperature coefficient for suppressing the input end of the switching power supply 220 from being impacted by a surge current (NTC) resistor 250; a temperature detection device 260 for detecting the ambient temperature of the negative temperature coefficient resistor 250; and a control device 230 for driving the stepping motor 210 in a full-step driving mode or a half-step driving mode according to the detected ambient temperature.

In the control system of the second embodiment, the negative temperature coefficient resistor 250 is usually provided at the input end of the switching power supply 220 to protect the circuit. As described above, when the ambient temperature is low, the resistance value of the negative temperature coefficient resistor 250 will increase, resulting in a decrease in the input voltage of the input terminal of the switching power supply 220 . In this way, the switching power supply 220 may not be able to meet the current requirement of the stepper motor, or the current requirement of the stepper motor may not be able to output normally. Therefore, in the control system of the second embodiment, the stepping motor is driven in the full-step driving mode or the half-step driving mode according to the ambient temperature, so as to realize safe and reliable operation.

FIG. 5 is a schematic flowchart of a control method of the control system of FIG. 4 . The control method of the control system of FIG. 4 will be described below with reference to FIG. 5 .

Steps S00 , S01 , S02 and S10 in FIG. 5 are the same as those in FIG. 3 , and will not be described in detail here. The steps in FIG. 5 that are different from those in FIG. 3 are mainly described below.

At step S02, it is determined whether the current driving mode is the full-step driving mode. If it is determined in step S02 that the current driving mode is not the full-step driving mode (ie, the half-step driving mode), proceed to step S210 to compare the ambient temperature T detected by the temperature detection device 260 with the first predetermined temperature value T1. The first predetermined temperature value T1 can be set according to the requirements of the half-step driving and the full-step driving of the stepping motor 210 . In other words, when the ambient temperature T is lower than the first temperature predetermined value T1, the requirement of half-step driving cannot be satisfied.

When it is determined in step S210 that the ambient temperature T is less than the first temperature predetermined value T1, since it cannot meet the requirement of half-step driving, the current driving mode (half-step driving mode) is switched to full-step driving mode in step S211. When the ambient temperature T is not less than the first predetermined temperature value T1, the current driving mode is maintained in the half-step driving mode, see step S222.

If it is determined in step S02 that the current driving mode is the full-step driving mode, then proceed to step S220 to compare the ambient temperature T detected by the temperature detection device 260 with the second predetermined temperature value T2, wherein the second predetermined temperature value T2 is greater than The first temperature predetermined value T1. Similarly, the second predetermined temperature value T2 can be set according to the requirements of half-step driving and full-step driving of the stepping motor 210 . In other words, when the ambient temperature T is higher than the second predetermined temperature value T2, it is possible to ensure stable driving of the stepping motor in the half-step driving mode.

When it is determined in step S220 that the ambient temperature T is greater than the second temperature predetermined value T2, since it can fully meet the requirements of half-step driving, the current driving mode (full-step driving mode) is switched to half-step driving mode in step S221 . When the ambient temperature T is not higher than the second predetermined temperature value T2, the current driving mode is maintained in the full-step driving mode, see step S212.

The driving manner in steps S212 and S222 may continue until the driving of the electronic expansion valve ends (see step S10).

The control system and control method for an electronic expansion valve according to the second embodiment actively detects the ambient temperature of the negative temperature coefficient resistance when the electronic expansion valve is activated and can determine the driving manner of the stepping motor according to the detected ambient temperature. That is, when the ambient temperature is low, the stepping motor can be driven in a full-step driving manner, thereby avoiding the situation that the normal driving cannot be performed due to insufficient current. When the ambient temperature is high, the stepping motor can be driven in a half-step driving manner, thereby realizing high-precision operation.

6 is a schematic functional block diagram of a control system for an electronic expansion valve according to a third embodiment of the present disclosure. As shown in FIG. 6 , the control system according to the third embodiment includes: a switching power supply 320 for supplying DC power to the stepping motor 310 of the electronic expansion valve; a voltage detection device 340 for detecting the input voltage of the input terminal of the switching power supply 320 ; A negative temperature coefficient (NTC) resistor 350 for suppressing the input end of the switching power supply 320 from being impacted by a surge current; a temperature detection device 360 for detecting the ambient temperature of the NTC resistor 350; The control device 330 of the stepping motor 310 is driven in the full-step driving mode or the half-step driving mode.

In the control system of the third embodiment, by detecting the input voltage of the switching power supply and the ambient temperature of the negative temperature coefficient resistance, the driving situation of the stepping motor is more accurately judged, so as to select an appropriate driving method, and thereby ensure the stepping motor normal drive of the motor.

FIG. 7 is a schematic flowchart of a control method of the control system of FIG. 6 . The control method of the control system of FIG. 6 will be described below with reference to FIG. 7 .

Steps S00 , S01 , S02 and S10 in FIG. 7 are the same as those in FIG. 3 , and will not be described in detail here. The steps in FIG. 7 that are different from those in FIG. 3 are mainly described below.

At step S02, it is determined whether the current driving mode is the full-step driving mode. If it is determined in step S02 that the current driving mode is not the full-step driving mode (ie, the half-step driving mode), then proceed to step S310 to compare the input voltage U detected by the voltage detection device 340 with the first predetermined voltage value U1.

When it is determined in step S310 that the input voltage U is not less than the predetermined value U1 of the first voltage, proceed to step S342 to maintain the current driving mode in the half-step driving mode. When it is determined in step S310 that the input voltage U is less than the first predetermined voltage value U1, then in step S330, the ambient temperature T detected by the temperature detection device 360 is compared with the first predetermined temperature value T1.

When it is determined in step S330 that the ambient temperature T is less than the first temperature predetermined value T1, since it cannot meet the requirement of half-step driving, the current driving mode (half-step driving mode) is switched to full-step driving mode in step S331. When the ambient temperature T is not less than the first predetermined temperature value T1, the current driving mode is maintained in the half-step driving mode, see step S342.

If it is determined in step S02 that the current driving mode is the full-step driving mode, then proceed to step S320 to compare the input voltage U detected by the voltage detection device 340 with the second predetermined voltage value U2, wherein the second predetermined voltage value U2 is greater than The first voltage is a predetermined value U1.

When it is determined in step S320 that the input voltage U is greater than the predetermined value U2 of the second voltage, since it can fully meet the requirements of half-step driving, the current driving mode (full-step driving mode) is switched to half-step driving mode in step S341 . When it is determined in step S320 that the input voltage U is not higher than the second predetermined voltage value U2, then it is determined in step S340 to compare the ambient temperature T detected by the temperature detection device 360 with the second predetermined temperature value T2, wherein the first The second predetermined temperature value T2 is greater than the first predetermined temperature value T1.

If it is determined in step S340 that the ambient temperature T is higher than the second temperature predetermined value T2, the current driving mode (full-step driving mode) is switched to the half-step driving mode in step S341. If it is determined in step S340 that the ambient temperature T is not higher than the second temperature predetermined value T2, the current driving mode is maintained in the full-step driving mode, see step S332.

The driving manner in steps S332 and S342 may continue until the driving of the electronic expansion valve is completed (see step S10).

The control system and control method of the third embodiment combine the input voltage of the first embodiment with the ambient temperature of the second embodiment, thereby more accurately judging and controlling the driving condition of the stepping motor.

8 is a schematic functional block diagram of a control system for an electronic expansion valve according to a fourth embodiment of the present disclosure. As shown in FIG. 8 , the control system according to the fourth embodiment includes: a switching power supply 420 that provides DC power to the stepping motor 410 of the electronic expansion valve; a negative temperature coefficient for suppressing the input end of the switching power supply 420 from being impacted by a surge current (NTC) resistor 450; and a control device 430 that controls to drive the stepping motor 410 in a full-step driving mode and switch to a half-step driving mode according to a set time when the electronic expansion valve is activated.

In the control system of the fourth embodiment, the control device 430 first drives the stepping motor in the full-step driving mode (ie, the safe driving mode) when activating the electronic expansion valve, and then makes the full-step driving continue for a predetermined period of time (ie, set time). The setting time can be set according to the situation of the stepper motor. For example, when the stepper motor is driven in the full-step drive mode for a set time, the operation of the electronic device reaches a steady state, and the heat generated by the electronic device is transferred to the surrounding environment and raises the ambient temperature, so that the resistance of the negative temperature coefficient resistor The value does not increase or increases very little (ie, does not significantly reduce the input voltage at the input of the switching power supply).

To this end, the control device 430 may include a timer 432 for timing the running time of the full-step drive.

FIG. 9 is a schematic flowchart of a control method of the control system of FIG. 8 . The control method of the control system of FIG. 8 will be described below with reference to FIG. 9 .

Steps S00 , S01 , S02 and S10 in FIG. 9 are the same as those in FIG. 3 , and will not be described in detail here. The steps in FIG. 9 that are different from those in FIG. 3 are mainly described below.

At step S02, it is determined whether the current driving mode is the full-step driving mode. If it is determined in step S02 that the current driving mode is not the full-step driving mode (ie, the half-step driving mode), then proceed to step S410 to switch the current driving mode (ie, the half-step driving mode) to the full-step driving mode.

Then, the operation time of the full-step driving mode is counted by the timer 432 (for convenience of description, it is hereinafter referred to as the measurement time). In step S411, it is determined whether or not the measurement time has reached the set time. If it is determined that the measurement time has not reached the set time, the full-step driving mode is maintained in step S412. If it is determined that the measurement time has reached the set time, it switches to the half-step drive mode in step S421.

If it is determined in step S02 that the current driving mode is the full-step driving mode, the process proceeds to step S420 to determine whether the measurement time reaches the set time. If it is determined that the measurement time has not reached the set time, the full-step driving mode is maintained in step S412. If it is determined that the measurement time has reached the set time, it switches to the half-step drive mode in step S421.

The driving manner in steps S412 and S421 may continue until the driving of the electronic expansion valve ends (see step S10).

According to the above control system, only a detection circuit including several resistors and detection devices needs to be added, so the added cost is low, and the development cycle can be shortened at the same time.

It should be understood that the above-described respective control methods of the present disclosure are not limited to the specific examples shown in the drawings. For example, the comparing step or the determining step may be repeated after a predetermined time interval to switch to half-step driving if a high driving condition is satisfied, and switch to full-step driving if a low driving condition is satisfied.

Also, alternatively or additionally, when the electronic expansion valve is activated, some less critical high current devices can be turned off, thereby ensuring the current supplied to the stepper motor.

Although various embodiments of the present disclosure have been described in detail herein, it should be understood that the present disclosure is not limited to the specific embodiments described and illustrated in detail herein, but may be Those skilled in the art realize other variations and modifications. All such variations and modifications fall within the scope of this disclosure.

Claims

A control system for an electronic expansion valve, wherein the electronic expansion valve includes a valve member and a motor, the valve member includes a valve body and a valve core that can move relative to the valve body, and the motor is configured to be capable of moving the spool to open or close the electronic expansion valve,

The control system includes:

a power supply device configured to provide power to the motor; and

A control device, wherein the modes in which the motor is driven by the control device include a first mode and a second mode, wherein the current required to drive the motor in the first mode is smaller than that of driving the motor in the second mode current required by the electric motor, and the control device is configured to selectively drive the electric motor in the first mode or the second mode according to preset electric motor drive-related parameters when the electronic expansion valve is activated.
The control system of claim 1, wherein the preset motor drive-related parameter includes an input voltage of the power supply device, the control system further comprising a voltage detection device configured to detect the the input voltage of the power supply unit,

Wherein, the control device drives the motor in the first mode or the second mode according to the input voltage.
The control system of claim 2, wherein the control device is configured to:

When the detected input voltage is lower than a predetermined value of a first voltage, the control device drives the motor in the first mode;

When the detected input voltage is higher than a second predetermined voltage value, the control device drives the motor in the second mode, the second voltage predetermined value is greater than the first voltage predetermined value; and

When the detected input voltage is greater than or equal to the predetermined first voltage value but less than or equal to the predetermined second voltage value, the control device drives the motor in the current mode.
The control system of claim 1, wherein the control system further comprises:

A negative temperature coefficient resistor, the negative temperature coefficient resistor is provided on the input side of the power supply device.
The control system according to claim 4, wherein the preset motor drive-related parameters include the ambient temperature of the negative temperature coefficient resistor,

The control system also includes:

A temperature detection device configured to detect an ambient temperature of the negative temperature coefficient resistor.
The control system of claim 5, wherein the control device is configured to:

When the detected ambient temperature is lower than a predetermined first temperature value, the control device drives the motor in the first mode;

When the detected ambient temperature is higher than a second predetermined temperature value, the control device drives the motor in the second mode, the second predetermined temperature value is greater than the first predetermined temperature value; and

When the detected ambient temperature is greater than or equal to the first predetermined temperature value but less than or equal to the second predetermined temperature value, the control device drives the motor in the current mode.
The control system according to claim 4, wherein the preset motor drive-related parameters include the input voltage of the power supply device and the ambient temperature of the negative temperature coefficient resistor,

The control system also includes:

a voltage detection device configured to detect an input voltage of the power supply device; and

A temperature detection device configured to detect an ambient temperature of the negative temperature coefficient resistor.
The control system of claim 7, wherein the control device is configured to:

When the detected input voltage is lower than a first predetermined voltage value and the detected ambient temperature is lower than a first predetermined temperature value, the control device drives the motor in the first mode;

When the detected input voltage is higher than a second predetermined voltage value or the detected ambient temperature is higher than a second predetermined temperature value, the control device drives the motor in the second mode, wherein the second the voltage predetermined value is greater than the first voltage predetermined value and the second temperature predetermined value is greater than the first temperature predetermined value; and

When the detected input voltage is greater than or equal to the first voltage predetermined value but less than or equal to the second voltage predetermined value and the detected ambient temperature is greater than or equal to the first temperature predetermined value but less than or equal to the second temperature a predetermined value, the control device drives the motor in the current mode.
The control system of claim 4, wherein,

The control system further includes a timer for measuring the drive time of the first mode,

Wherein, the control system is configured to select to drive the motor in the first mode when activating the electronic expansion valve, and the preset motor drive-related parameters include driving the motor in the first mode time, and

The second mode is switched when the drive time reaches a set time.
The control system according to any one of claims 1 to 9, wherein the motor is a stepping motor, the power supply device is a switching power supply, the first mode is a full-step driving mode, and the second mode For half-step drive mode.
A control method for an electronic expansion valve, wherein the electronic expansion valve includes a valve member and a motor, the valve member includes a valve body and a valve core that can move relative to the valve body, and the motor is configured to be capable of moving the spool to open or close the electronic expansion valve,

The control method includes the following steps:

obtaining parameters related to the driving of the motor; and

Power is supplied to the motor through a power supply device to drive the motor,

The motor is driven in a first mode or a second mode according to the parameter, and the current required to drive the motor in the first mode is smaller than the current required to drive the motor in the second mode current.
The control method according to claim 11, wherein,

Obtaining parameters related to driving of the motor includes detecting an input voltage of the power supply; and

The motor is selected to be driven in the first mode or the second mode according to the detected input voltage.
The control method according to claim 12, further comprising:

When the detected input voltage is lower than the predetermined value of the first voltage, selecting to drive the motor in the first mode;

selecting to drive the motor in the second mode when the detected input voltage is higher than a second predetermined voltage value, the second predetermined voltage value being greater than the first predetermined voltage value; and

When the detected input voltage is greater than or equal to the predetermined first voltage value but less than or equal to the predetermined second voltage value, the current mode is maintained to drive the motor.
The control method according to claim 11, further comprising:

A negative temperature coefficient resistor is provided on the input side of the power supply device.
The control method according to claim 14, wherein,

Obtaining parameters related to driving of the motor includes detecting an ambient temperature of the negative temperature coefficient resistor; and

The motor is selected to be driven in the first mode or the second mode according to the detected ambient temperature.
The control method according to claim 15, further comprising:

When the detected ambient temperature is lower than a predetermined value of a first temperature, selecting to drive the motor in the first mode;

Selecting to drive the motor in the second mode when the detected ambient temperature is higher than a second predetermined temperature value, the second predetermined temperature value being greater than the first predetermined temperature value; and

When the detected ambient temperature is greater than or equal to the first predetermined temperature value but less than or equal to the second predetermined temperature value, the current mode is maintained to drive the motor.
The control method according to claim 14, wherein,

Obtaining parameters related to driving of the motor includes detecting an input voltage of the power supply device and detecting an ambient temperature of the negative temperature coefficient resistor; and

The motor is selected to be driven in the first mode or the second mode according to the detected input voltage and ambient temperature.
The control method according to claim 17, further comprising:

Selecting to drive the motor in the first mode when the detected input voltage is lower than the first predetermined voltage value and the detected ambient temperature is lower than the first predetermined temperature value;

When the detected input voltage is higher than a second voltage predetermined value or the detected ambient temperature is higher than a second temperature predetermined value, the motor is selected to be driven in the second mode, wherein the second voltage predetermined value is greater than the a first voltage predetermined value and the second temperature predetermined value is greater than the first temperature predetermined value; and

When the detected input voltage is greater than or equal to the first predetermined voltage value but less than or equal to the second predetermined voltage value and the detected ambient temperature is greater than or equal to the first predetermined temperature value but less than or equal to the second predetermined temperature value, The current mode is maintained to drive the motor.
The control method according to claim 14, wherein,

Selecting to drive the electric motor in the first mode when activating the electronic expansion valve;

Obtaining parameters related to driving of the motor includes measuring a driving time of the first mode; and

The second mode is switched when the drive time reaches a set time.
The control method according to any one of claims 11 to 19, further comprising:

When starting to drive the motor, it is first determined whether the current mode is the first mode or the second mode.