Electronic expansion valve driving device and refrigeration equipment

Abstract

The invention provides an electronic expansion valve driving device and refrigeration equipment, and belongs to the technical field of control. The power driving module is connected with the main control module and used for driving a motor in the electronic expansion valve; the locked-rotor detection module is connected with the main control module or the power driving module and used for determining the running state of the motor by monitoring one or more running parameters of the motor in the process that the power driving module drives the motor; and controlling the power driving module to stop driving the motor on the basis that the running state of the motor is locked-rotor. The locked-rotor detection module is introduced to monitor the operation parameters reflecting the rotation condition of the motor in real time, so that the locked-rotor fault which cannot be perceived by the traditional technology can be accurately identified. Therefore, the risk of burnout of the motor due to overload heating is avoided. And meanwhile, the operation reliability and the service life of the driving device and even the whole refrigeration equipment are improved.

Description

Technical Field

[0001] This invention relates to the field of control technology, and in particular to an electronic expansion valve drive device and a refrigeration equipment. Background Technology

[0002] In existing semiconductor refrigeration compressor systems, the electronic expansion valve drive device serves as the core control component, primarily enabling precise adjustment of the electronic expansion valve opening to control the refrigerant flow rate and match the refrigeration requirements of the semiconductor refrigeration module.

[0003] During long-term use, electronic expansion valves may become stuck due to refrigerant impurities, valve core mechanical wear, or motor bearing jamming.

[0004] When stall occurs, the main control module will continuously output drive signals, causing the motor in the electronic expansion valve to overheat and be damaged. At the same time, the electronic expansion valve cannot operate to the specified opening degree, the refrigerant flow is out of control, and the temperature of the refrigeration unit fluctuates greatly and is unstable. In severe cases, it will cause the compressor to start and stop frequently, shortening the overall life of the equipment. Summary of the Invention

[0005] This invention provides an electronic expansion valve drive device and a refrigeration equipment to solve the problems in the prior art where, when a stall occurs, the motor in the electronic expansion valve overheats and is damaged, and the refrigerant flow becomes uncontrolled, resulting in large temperature fluctuations and unstable control of the refrigeration unit. In severe cases, this leads to frequent compressor start-stop cycles, shortening the overall lifespan of the equipment. This invention can accurately identify stall faults that cannot be detected by traditional technologies, avoiding the risk of motor burnout due to overload and improving the operational reliability and service life of the drive device and the entire refrigeration equipment.

[0006] This invention provides an electronic expansion valve driving device, comprising the following modules: Main control module; A power drive module, connected to the main control module, is used to drive the motor inside the electronic expansion valve; A stall detection module, connected to the main control module or the power drive module, is used to determine the operating status of the motor by monitoring one or more operating parameters of the motor during the process of the power drive module driving the motor; and Since the motor is in a stalled state, the power drive module is controlled to stop driving the motor.

[0007] According to the present invention, an electronic expansion valve driving device is provided, wherein the operating parameters include the back electromotive force of the motor.

[0008] According to an electronic expansion valve driving device provided by the present invention, the electronic expansion valve driving device further includes: The fault alarm module is connected to the stall detection module and is used to output the first alarm information when the motor is in a stalled operating state. The first alarm information includes local alarm information and / or remote alarm information.

[0009] According to an electronic expansion valve driving device provided by the present invention, the operating parameters include the driving current of the motor and / or the motor temperature; The stall detection module is also used for: Based on the drive current being greater than or equal to a preset current threshold or the motor temperature being greater than a preset rated temperature, perform at least one of the following operations: Control the power drive module to stop outputting the drive signal that drives the motor; The fault alarm module is controlled to output a second alarm message.

[0010] According to an electronic expansion valve driving device provided by the present invention, the electronic expansion valve driving device further includes: An isolated power supply module, wherein the input terminal of the isolated power supply module is used to input a first DC voltage, the first output terminal of the isolated power supply module is connected to the main control module and the stall detection module respectively, and is used to provide a second DC voltage to the main control module, and the second output terminal of the isolated power supply module is connected to the power drive module, and is used to provide a third DC voltage to the main control module; Wherein, the first DC voltage is greater than the third DC voltage, and the third DC voltage is greater than the second DC voltage.

[0011] According to an electronic expansion valve driving device provided by the present invention, the electronic expansion valve driving device further includes: A transient suppression diode is disposed at the input terminal of the isolated power supply module; and / or A common-mode inductor is located at the input terminal of the isolated power supply module.

[0012] According to an electronic expansion valve driving device provided by the present invention, the electronic expansion valve driving device further includes: An isolated signal transmission module is connected in series between the main control module and the power drive module to isolate the signals transmitted between the main control module and the power drive module.

[0013] According to the present invention, an electronic expansion valve driving device is provided, wherein the isolated signal transmission module includes: An optocoupler, wherein the LED anode and the LED cathode of the optocoupler are connected to the output circuit of the main control module; and the collector and the emitter of the photodetector in the optocoupler are connected to the input circuit of the power drive module; and / or A digital isolator, wherein the low-voltage control circuit of the digital isolator is connected to the output circuit of the main control module, and the high-voltage execution circuit of the digital isolator is connected to the input circuit of the power drive module.

[0014] According to an electronic expansion valve driving device provided by the present invention, the electronic expansion valve driving device further includes: An isolation amplifier is provided, the input of which is used to input analog signals that control the operation of the main control module, and the output of which is connected to the signal input of the main control module.

[0015] The present invention also provides a refrigeration device, comprising: Electronic expansion valve; The electronic expansion valve drive device as described in any one of the above descriptions is used to drive the electronic expansion valve to operate.

[0016] This invention provides an electronic expansion valve drive device and refrigeration equipment. By introducing a stall detection module to monitor operating parameters reflecting motor rotation in real time, it can accurately identify stall faults that are imperceptible to traditional technologies. Once stall is detected, the main control module works in conjunction with the stall detection module, no longer blindly continuing to output drive signals, but actively controlling the power drive module to stop driving the motor. This process cuts off the path of continuous power supply to the motor in a stalled state, thus avoiding the risk of motor burnout due to overload and overheating. At the same time, because the system can accurately know that the valve has not reached the designated position, it avoids misjudgments by the upper control system based on incorrect valve position information, thereby preventing temperature fluctuations and impacts on the compressor caused by refrigerant flow runaway, fundamentally improving the operational reliability and service life of the drive device and even the entire refrigeration equipment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is one of the schematic diagrams of the electronic expansion valve driving device provided by the present invention.

[0019] Figure 2 This is the second schematic diagram of the electronic expansion valve driving device provided by the present invention.

[0020] Figure 3 This is the third schematic diagram of the electronic expansion valve driving device provided by the present invention.

[0021] Figure 4 This is the fourth schematic diagram of the electronic expansion valve driving device provided by the present invention.

[0022] Figure 5 This is the fifth schematic diagram of the electronic expansion valve driving device provided by the present invention.

[0023] Figure label: 101: Main control module; 102: Power drive module; 103: Stall detection module; 104: Fault alarm module; 105: Isolated power supply module; 106: Isolated signal transmission module. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] Furthermore, the term "and / or" used in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0026] The present invention provides an electronic expansion valve driving device, the execution subject of which can be the driving device itself, and the method is implemented through the coordinated work of various functional modules integrated within it.

[0027] The following is combined Figures 1 to 5 The present invention describes an electronic expansion valve drive device and a refrigeration device.

[0028] Figure 1 This is one of the schematic diagrams of the electronic expansion valve driving device provided by the present invention, such as... Figure 1 As shown, it includes the following modules: Main control module 101; The power drive module 102 is connected to the main control module 101 and is used to drive the motor inside the electronic expansion valve. A stall detection module 103, connected to the main control module 101 or the power drive module 102, is used to determine the motor's operating status by monitoring one or more operating parameters of the motor during the motor's operation by the power drive module 102; and Since the motor is in a stalled state, the control power drive module 102 stops driving the motor.

[0029] In some embodiments, the main control module 101 may be a microcontroller unit (MCU), a digital signal processor (DSP), a field-programmable gate array (FPGA), or a dedicated integrated circuit. The function of the main control module 101 is to receive operating instructions from a higher-level control system (e.g., the main controller of a refrigerator), which may indicate the target opening degree that the electronic expansion valve needs to achieve. Based on this target opening degree, the main control module 101 performs calculations using an internally preset algorithm to generate drive control signals for controlling the motor operation, such as a pulse width modulation (PWM) signal sequence.

[0030] In some embodiments, the power drive module 102 is connected to the signal output terminal of the main control module 101. Its function is to receive the weak drive control signal from the main control module 101 and amplify it to generate a sufficiently large current and voltage to drive the motor inside the electronic expansion valve. In specific implementations, the power drive module 102 can be a circuit composed of power switching devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated-gate bipolar transistors (IGBTs) and their drive circuits, or it can be a commercially available integrated motor drive chip.

[0031] In related technologies, when the electronic expansion valve becomes blocked due to impurities, wear, or other reasons, the main control module 101 cannot detect this abnormal state and will continue to output drive signals to the power drive module 102, causing the power drive module 102 to continuously supply a large current to the motor. This will not only cause the motor to burn out due to overheating in a very short time, but also cause the refrigerant flow to run out of control because the valve opening is stuck in the wrong position, resulting in drastic temperature fluctuations in the refrigeration system and even damage to the compressor.

[0032] Based on this, a stall detection and linkage control mechanism is introduced in the technical solution of this embodiment.

[0033] Specifically, the electronic expansion valve drive device also includes a stall detection module 103. The function of this module is to monitor and determine the motor's operating status in real time during the process of the power drive module 102 driving the motor. The operating status here can be understood as the physical state that characterizes whether the motor rotor is rotating normally, and it can be specifically divided into normal operating state and stall state.

[0034] To determine the motor's operating status, the stall detection module 103 monitors one or more of the motor's operating parameters. These operating parameters refer to physical quantities that dynamically reflect the motor's rotation during operation. These physical quantities exhibit significant and distinguishable differences between normal motor rotation and stall conditions.

[0035] In one possible implementation, the operating parameter can be an electrical characteristic quantity related to motor rotation. For example, when the motor rotates, its internal coils generate a specific electrical response, and when the rotor stops rotating due to mechanical jamming, this electrical response undergoes a characteristic change. The stall detection module 103 can determine the occurrence of stall by collecting and analyzing the changing trend of this electrical characteristic quantity.

[0036] In another possible implementation, the operating parameter could also be a mechanical characteristic quantity related to motor rotation. For example, a motor produces smooth vibrations and sounds when operating normally, but its vibration spectrum or sound characteristics may change abruptly when stall occurs. The stall detection module 103 can collect these mechanical characteristic quantities by being equipped with appropriate sensors (such as an accelerometer or microphone) and identify stall through signal processing.

[0037] Specifically, the process by which the stall detection module 103 determines the motor's operating state can be as follows: The module internally presets one or more benchmark thresholds for determining stall. During motor operation, the module continuously acquires real-time operating parameter values ​​and compares them with these benchmark thresholds. When the monitored real-time parameter values ​​deviate significantly from the range of parameters during normal operation and reach or exceed the benchmark threshold, the stall detection module 103 determines that the current motor operating state is stall.

[0038] The core of this embodiment lies in the fact that when a motor stall is detected, the device will execute an active protection action. Specifically, this function is implemented collaboratively by the main control module 101 and the stall detection module 103. When the stall detection module 103 determines that the motor has stalled, it generates a stall status signal and sends this signal to the main control module 101. Upon receiving the stall status signal, the main control module 101 immediately changes its normal control logic and executes a preset protection program. The core of this protection program is to control the power drive module 102 to stop driving the motor.

[0039] In some embodiments, the control to stop the drive can be implemented in a variety of ways. For example, the main control module 101 can immediately stop generating and outputting drive control signals (such as PWM signals); or, the main control module 101 can send a disable signal to an enable pin of the power drive module 102, thereby directly shutting down the output stage of the power drive module 102. Regardless of the method used, the ultimate goal is to quickly cut off the drive current applied to the motor coils.

[0040] In this embodiment, the electronic expansion valve drive device incorporates a stall detection module 103 to monitor operating parameters reflecting motor rotation in real time, thereby accurately identifying stall faults that are imperceptible by traditional technologies. Once stall is detected, the main control module 101 works in conjunction with the stall detection module 103, no longer blindly continuing to output drive signals, but actively controlling the power drive module 102 to stop driving the motor. This process cuts off the path of continuous power supply to the motor in a stalled state, thus avoiding the risk of the motor burning out due to overload and overheating. At the same time, since the system can accurately know that the valve has not reached the designated position, it avoids misjudgments by the upper control system based on incorrect valve position information, thereby preventing temperature fluctuations and impacts on the compressor caused by refrigerant flow runaway, fundamentally improving the operational reliability and service life of the drive device and even the entire refrigeration equipment.

[0041] In some embodiments, the motor within the electronic expansion valve may specifically be a stepper motor, and the operating parameters include the motor's back electromotive force.

[0042] Stepper motors are widely used in electronic expansion valves that require precise opening control because they can achieve precise positioning and speed regulation by controlling the number and frequency of input pulses. Correspondingly, the operating parameter monitored by the stall detection module 103 is specifically the back electromotive force of the motor.

[0043] Specifically, during normal operation, the rotor of a stepper motor rotates synchronously under the drive of the rotating magnetic field generated by the stator windings. Simultaneously, the rotating permanent magnet rotor magnetic field induces a voltage in the non-energized stator windings. This voltage is opposite in direction to the driving voltage applied to the windings and is therefore called back electromotive force (EMF). The amplitude of the back EMF is proportional to the motor's rotational speed, and its waveform is closely related to the motor's structure and operating conditions. Therefore, the back EMF is an electrical characteristic quantity that can very accurately reflect the actual rotation of the stepper motor rotor.

[0044] During normal operation of the drive unit driving the motor, the stall detection module 103 collects the voltage signal on the motor windings in real time through a sampling circuit. Due to the presence of the drive pulses, the back electromotive force (EMF) signal is usually submerged in the drive voltage and is not easy to measure directly. Therefore, a feasible monitoring method is to sample the voltage across the windings within a specific time window of each pulse cycle of the stepper motor drive signal (e.g., during the drive current decay phase or the winding floating phase). By filtering and processing the sampled mixed voltage signal, the signal component that represents the characteristics of the back EMF can be extracted.

[0045] When the valve core or transmission mechanism of the electronic expansion valve becomes mechanically stuck, causing the rotor of the stepper motor to be unable to rotate following the rotating magnetic field, a stall occurs. At the moment the stall occurs, the motor speed drops sharply to zero, which causes its back electromotive force to decrease rapidly or almost disappear.

[0046] The stall detection module 103 utilizes this significant physical phenomenon to determine the motor's operating status. Specifically, the stall detection module 103 performs the following checks internally: Establishing a benchmark: The stall detection module 103 can preset a normal threshold or a dynamically changing expected range of back electromotive force based on the rated speed of the motor or the current commanded speed.

[0047] Real-time comparison: During motor operation, the module continuously monitors and calculates the real-time back electromotive force value.

[0048] Stall detection: The real-time back EMF value is compared with a preset benchmark. If the back EMF value is detected to be continuously lower than a preset lower threshold for a period of time, or if its rate of change shows an abnormal sudden drop, the stall detection module 103 can determine that the motor has switched from normal operation to stall state.

[0049] For example, the stall detection module 103 can be set with a judgment logic: if the detected back EMF amplitude is lower than 30% of the amplitude that should be under normal operation within N consecutive drive steps (N is a preset positive integer, such as 5), then the motor is determined to be stalled.

[0050] Once the stall detection module 103 determines that a stall has occurred based on the monitoring of the back electromotive force, it triggers the main control module 101 to execute subsequent protection actions, namely, controlling the power drive module 102 to stop driving the motor.

[0051] In this embodiment, by specifying the monitored operating parameters as the back electromotive force (EMF) of the motor, a highly accurate and reliable physical basis is provided for stall detection. Compared to monitoring parameters such as current or temperature, which may be affected by load fluctuations, the back EMF is directly related to the actual speed of the motor. Using it as a basis for judgment can identify stall events more quickly (usually within tens of milliseconds) and more accurately. This back EMF-based monitoring mechanism enables the drive device to capture the physical fact of valve jamming immediately and cut off the drive energy, thereby achieving the most direct and effective protection for the motor and ensuring the correctness of the entire refrigeration system control logic, significantly improving the intelligence level and operational reliability of the device.

[0052] In some embodiments, such as Figure 2 As shown, the electronic expansion valve drive device also includes: The fault alarm module 104 is connected to the stall detection module 103 and is used to output the first alarm information when the motor is in a stalled state. The first alarm information includes local alarm information and / or remote alarm information.

[0053] In this embodiment, although the electronic expansion valve drive can actively stop driving the motor after detecting a stall, thus protecting the motor itself, the maintenance personnel of the entire refrigeration system may not be able to detect the fault in a timely and accurate manner. For example, maintenance personnel may only observe abnormal temperature control in the refrigeration system, but it is difficult to pinpoint the problem to a stall fault in the electronic expansion valve in the first instance. They still need to conduct a step-by-step investigation, resulting in a long troubleshooting cycle and high costs.

[0054] To address this issue, the electronic expansion valve actuator also includes a fault alarm module 104. This fault alarm module 104 is electrically connected to the main control module 101 (or directly to the stall detection module 103) and is used to receive fault indication signals from them and convert them into alarm information that can be sensed or read by external systems.

[0055] Specifically, when the stall detection module 103 determines that the motor is stalled, in addition to triggering the main control module 101 to perform a protection action to stop the drive, it will also simultaneously (or the main control module 101 will control the fault alarm module 104 to output the first alarm information while performing the protection action) the first alarm information here specifically refers to the alarm triggered by the motor stalling.

[0056] The first alarm message can take different forms to suit different application scenarios and operation and maintenance needs.

[0057] In one specific implementation, the first alarm information may include local alarm information. Local alarm information refers to alarm signals that can be directly observed or heard by on-site maintenance personnel at the physical location of the drive unit. This method facilitates rapid fault location on-site. For example, the fault alarm module 104 may include one or more light-emitting diode (LED) indicator lights. During normal operation, the indicator light can remain constantly lit or off; when a stall fault occurs, the main control module 101 can control the indicator light to flash at a specific frequency (e.g., 1Hz) to visually alert on-site personnel. As another example, the fault alarm module 104 may also include a buzzer. When a stall is detected, the main control module 101 can drive the buzzer to emit a continuous or intermittent beeping sound to provide an audible alarm. Of course, local alarm information can also be a combination of light and sound signals, such as a flashing red light accompanied by a buzzer, to provide a stronger warning effect.

[0058] In another specific implementation, the first alarm information may include remote alarm information. Remote alarm information refers to signals that can be received and analyzed by a remote central control system or monitoring platform, suitable for situations requiring centralized monitoring and unattended operation, such as large commercial cold chain rooms or medical cryogenic storage systems. To implement remote alarms, the fault alarm module 104 may include a relay. This relay is controlled by the main control module 101, and its contacts (normally open or normally closed) are connected to the signal acquisition circuit of the upstream refrigeration unit's main control system. Under normal operation, the relay remains in one state (e.g., open); when a stall fault occurs, the main control module 101 controls the relay coil to be energized or de-energized, causing its contacts to switch to another state (e.g., closed). By detecting the change in the state of the relay contacts, the upstream main control system can detect that the electronic expansion valve drive has experienced a stall fault, thereby displaying a pop-up alarm or recording a fault log on the central monitoring interface, facilitating remote monitoring and operation and maintenance scheduling.

[0059] In some embodiments, the first alarm information may include both local and remote alarm information, i.e., a combination of local and / or remote alarm information. For example, when a stall occurs, the LED indicator on the device starts flashing, and the relay also activates, transmitting a fault signal. This design balances the convenience of on-site troubleshooting with the real-time nature of remote centralized monitoring, providing the most comprehensive fault feedback mechanism.

[0060] In this embodiment, based on the implementation of stall detection and active protection, a complete path from fault occurrence to information output is established by adding a fault alarm module 104. When a stall fault occurs, the device can not only stop the drive to protect the motor, but also issue a local and / or remote alarm. In this way, maintenance personnel can quickly and accurately locate the root cause of the problem to the stall fault of the electronic expansion valve through intuitive audible and visual prompts or alarms from the remote monitoring platform, which greatly shortens the fault diagnosis time, reduces maintenance costs, and provides an important guarantee for the rapid repair and continuous reliable operation of the system.

[0061] In some embodiments, operating parameters include the motor drive current and / or motor temperature; The stall detection module 103 is also used for: Based on the drive current being greater than or equal to a preset current threshold or the motor temperature being greater than a preset rated temperature, perform at least one of the following operations: The control power drive module 102 stops outputting the drive signal for the drive motor; The control fault alarm module 104 outputs the second alarm information.

[0062] In this embodiment, the motor of the electronic expansion valve may not immediately show a complete disappearance of back electromotive force in the initial stage of stall. Furthermore, in certain low-speed stall conditions, relying solely on the back electromotive force as a single parameter may lead to delays or misjudgments. In addition to mechanical stall, abnormalities in the drive circuit itself or sudden changes in load can also cause an abnormal increase in the motor drive current, which can also threaten the safety of the motor and drive unit.

[0063] To address the aforementioned complexities, this embodiment expands the monitoring dimensions of the stall detection module 103. Specifically, the operating parameters monitored by the stall detection module 103, in addition to the back electromotive force mentioned in the previous embodiment, also include the motor's drive current and / or motor temperature. This means that the stall detection module 103 can simultaneously or selectively comprehensively assess the motor's health status from multiple physical dimensions, such as electrical and thermal aspects.

[0064] Monitoring of the drive current can be achieved by connecting a low-resistance sampling resistor in series in the output circuit of the power drive module 102. The stall detection module 103 measures the voltage drop across the sampling resistor and calculates the actual drive current flowing through the motor coil in real time according to Ohm's law (I = V / R).

[0065] Motor temperature monitoring can be achieved by attaching a thermistor to the surface of the motor housing or near the coil. The stall detection module 103 obtains the real-time motor temperature by collecting the resistance change of the thermistor and consulting a preset resistance-temperature correspondence table.

[0066] Based on the newly added monitoring parameters, the stall detection module 103 is also equipped with new judgment and control logic. This logic is independent of or supplements the stall judgment based on back electromotive force. Specifically, the stall detection module 103 internally presets a preset current threshold and a preset rated temperature.

[0067] The preset current threshold is a safe upper limit set based on the motor's rated operating current and the peak current it can withstand. For example, for a stepper motor with a rated current of 1A, its preset current threshold can be set to 1.5A. When the real-time drive current detected by the stall detection module 103 is greater than or equal to this preset current threshold, the motor can be determined to be in an overcurrent state. This overcurrent state is most likely caused by stall, or it may be caused by other faults such as a short circuit.

[0068] The preset rated temperature is an upper limit of safe operating temperature determined based on the motor's insulation class and the heat resistance of its materials. For example, for a Class B insulated motor, the maximum allowable operating temperature is 130℃, so the preset rated temperature can be conservatively set to 120℃. When the real-time motor temperature detected by the stall detection module 103 exceeds this preset rated temperature, the motor is determined to be in an overheated state. Motor overheating is usually the end result of prolonged overcurrent or stall.

[0069] When the stall detection module 103 determines a fault based on any of the above conditions (drive current greater than or equal to a preset current threshold or motor temperature greater than a preset rated temperature), it will perform at least one of the following operations: The power drive module 102 stops outputting drive signals to the drive motor. This operation enables rapid hardware-level protection. For example, the stall detection module 103 can directly act on the enable / reset pin of the power drive module 102 to cut off the current output as quickly as possible. This response is typically much faster than software control via the main control module 101, and is especially crucial for preventing damage caused by instantaneous high currents.

[0070] The control fault alarm module 104 outputs a second alarm message. This second alarm message is a specific alarm signal used to indicate faults caused by overcurrent or overtemperature. It may be the same as or different from the first alarm message caused by stall (e.g., based on back EMF) in the aforementioned embodiments. For example, the fault alarm module 104 can use LEDs to distinguish between stall faults and overcurrent / overtemperature faults by flashing at different frequencies, thereby providing maintenance personnel with more accurate fault diagnosis information. This second alarm message can also include local alarms and / or remote alarms.

[0071] In this embodiment, the electronic expansion valve drive device constructs a multi-dimensional, multi-layered, three-dimensional protection system integrating back electromotive force, drive current, and motor temperature. First, by monitoring the drive current, instantaneous protection against motor overcurrent faults is achieved. This not only detects stall conditions but also addresses other electrical faults, providing a rapid response. Second, monitoring the motor temperature compensates for the potential insensitivity of other parameters in some slowly developing fault scenarios. When the stall detection module 103 determines a fault based on these new parameters, it can independently or collaboratively execute operations such as cutting off the drive and outputting specific alarm information. This design diversifies the fault diagnosis and protection execution paths, greatly enhancing the robustness and safety of the drive device. It ensures that any motor abnormality caused by any reason can be detected and effectively handled in a timely manner, thereby maximizing the protection of the motor and drive device itself and providing richer diagnostic information for system maintenance.

[0072] In some embodiments, such as Figure 3 As shown, the electronic expansion valve drive device also includes: An isolated power supply module 105 has an input terminal for receiving a first DC voltage, a first output terminal for connecting to the main control module 101 and the stall detection module 103 respectively, for providing a second DC voltage to the main control module 101, and a second output terminal for connecting to the power drive module 102, for providing a third DC voltage to the main control module 101. Among them, the first DC voltage is greater than the third DC voltage, and the third DC voltage is greater than the second DC voltage.

[0073] Specifically, in industrial settings or complex electromagnetic environments, drive devices are not only subject to interference from their internal power devices, but also to external factors such as power grid fluctuations and surges. These interferences can directly penetrate the device through the power supply circuit, potentially causing malfunctions or even damage to precision core components such as the main control module 101, thereby affecting the reliability of the stall detection and protection functions in the aforementioned embodiments.

[0074] To address this issue, the electronic expansion valve drive device in this embodiment further includes an isolated power supply module 105. The core principle of the isolated power supply module 105 is electrical isolation. This means that there is no direct wire connection between the first output terminal and its power supply low-voltage circuit, and the second output terminal and its power supply high-voltage circuit; each has its own independent grounding reference plane.

[0075] When the power drive module 102 performs high-frequency switching operations to drive the motor, it generates a large amount of switching noise and inrush current, which pollutes its power supply circuit (i.e., the circuit containing the third DC voltage). Due to the presence of the isolated power supply module 105, this noise is confined to the independent ground plane of the high-voltage circuit and cannot be conducted to the low-voltage circuit through a shared grounding path. This provides a clean power supply environment for the main control module 101, which serves as the control core, and the stall detection module 103, which is responsible for precise judgment. A stable, interference-free second DC voltage ensures that the main control module 101 can accurately time, flawlessly execute logical judgments, and accurately receive stall status signals from the stall detection module 103.

[0076] In some embodiments, the first DC voltage is 24V, the third DC voltage is 12V, and the second DC voltage is 3.3V.

[0077] In some embodiments, there is also electrical isolation between the input and output of the isolated power module 105 (e.g., the isolation voltage can be selected as different levels such as 1500Vrms or 2500Vrms depending on the application requirements). This feature effectively blocks interference such as voltage spikes or surges from the external power grid (i.e., the first DC voltage input terminal) before they are transmitted to the internal circuitry, thereby protecting the entire drive unit from the effects of external power quality degradation and significantly improving the overall reliability and environmental adaptability of the device.

[0078] In some embodiments, the electronic expansion valve actuation device further includes: A transient suppression diode is located at the input terminal of the isolated power supply module 105; and / or A common-mode inductor is located at the input terminal of the isolated power supply module 105.

[0079] Specifically, in industrial sites or complex commercial environments, the 24V DC power grid (i.e., the first DC voltage) supplying power to the drive unit is not an ideal stable power source. It is often subject to interference from factors such as the start-up and shutdown of other high-power equipment in the same power grid and the operation of frequency converters, generating electromagnetic interference such as voltage spikes, surges, and fast transient pulse groups. If these disturbances directly enter the isolated power module 105, they may still exceed its own protection capabilities, causing impacts on its internal components, or even breakdown damage, thereby affecting the subsequent main control module 101 and power drive module 102, leading to abnormal operation or permanent damage to the entire drive unit.

[0080] In one embodiment, a transient voltage suppressor diode is connected in parallel at the input terminal of the isolated power module 105, specifically between the positive and negative terminals of the external 24V DC power supply. The transient voltage suppressor diode is a high-efficiency surge absorption device. Its core working principle is as follows: when the voltage across its terminals is lower than its nominal breakdown voltage, it exhibits extremely high impedance, equivalent to an open circuit, and does not affect the normal operation of the circuit; however, once the voltage across its terminals momentarily exceeds its breakdown voltage due to surges or electrostatic discharge, its impedance immediately becomes extremely low, bypassing the large transient current to ground, thereby clamping the voltage across its terminals to a preset safe level. Through this clamping effect, the transient voltage suppressor diode can effectively absorb and suppress voltage spikes from the power line, protecting the downstream isolated power module 105 from overvoltage surges. For example, when a spike pulse of several hundred volts appears on the external power line, the transient voltage suppressor diode can ensure that the voltage entering the isolated power module 105 is always limited to its tolerable safe range (e.g., below 36V).

[0081] In one embodiment, a common-mode inductor is connected in series in the input circuit of the isolated power module 105, typically connected simultaneously to both the positive and negative (ground) input lines. Essentially, a common-mode inductor is a dual-coil inductor wound on the same ferrite core, with both coils wound in the same direction. Its working principle is as follows: when differential-mode current (i.e., the normal operating current, equal in magnitude and opposite in direction on both positive and negative lines) flows, the magnetic fields generated by the two coils cancel each other out, resulting in extremely low inductive reactance and almost no attenuation of normal signals. However, when common-mode current (i.e., interference current, in the same direction on both positive and negative lines) flows, the magnetic fields generated by the two coils superimpose, causing the common-mode inductor to exhibit extremely high inductive reactance, thus strongly suppressing common-mode interference signals. In practical applications, interference induced by external electromagnetic fields or generated by line coupling often exists in common-mode form. Therefore, by setting a common-mode inductor, the common-mode interference noise conducted on the power line can be effectively filtered out, further purifying the power supply to the isolated power module 105 and reducing the probability of it malfunctioning due to external electromagnetic interference.

[0082] In some embodiments, such as Figure 4 As shown, the electronic expansion valve drive device also includes: An isolated signal transmission module 106 is connected in series between the main control module 101 and the power drive module 102 to isolate the signals transmitted between the main control module 101 and the power drive module 102.

[0083] In actual operating scenarios of drive devices, such as in commercial cold chain machine rooms or precision electronic heat dissipation systems, the simultaneous operation of multiple high-power devices (such as compressors and frequency converters) generates strong electromagnetic interference. Simultaneously, the power drive module 102 within the device itself is a powerful noise source when performing high-frequency switching operations to drive the motor. This electromagnetic noise, especially high-frequency switching noise, can easily couple backwards through the signal transmission path or intrude into the control loop of the main control module 101.

[0084] Because the main control module 101 (e.g., an MCU) is a sophisticated digital logic circuit, it requires extremely high purity of signal levels. If the drive control signal is interfered with by noise, resulting in waveform distortion, glitches, or level jumps, the main control module 101 may incorrectly interpret these signals, leading to chaotic output logic, and potentially even causing the program to crash or freeze. This interference will ultimately manifest as deviations or complete loss of control in the opening adjustment of the electronic expansion valve, violating the original intention of precise control.

[0085] To fundamentally block this interference path, the isolated signal transmission module 106 in this embodiment is connected in series between the main control module 101 and the power drive module 102. This series connection means that all drive control signals issued by the main control module 101 are no longer directly transmitted to the power drive module 102, but must first be processed through the isolated signal transmission module 106.

[0086] The core function of this isolated signal transmission module 106 is to isolate the signals transmitted between the main control module 101 and the power drive module 102. Specifically, this isolation refers to Galvanic isolation. It transmits signals through non-directly conductive means (such as optical, magnetic, or capacitive coupling), thereby physically severing the direct electrical connection (i.e., common ground loop) between the weak-current circuit of the main control module 101 and the strong-current circuit of the power drive module 102.

[0087] Specifically, an isolation barrier is established inside the isolated signal transmission module 106. The signal enters the module from the input terminal of the main control module 101 and is converted into an intermediate medium (such as an optical signal or a changing magnetic field) capable of crossing the isolation barrier. On the other side of the module, this intermediate medium is converted back into the original electrical signal and output to the power drive module 102. Because no physical wires connect across the barrier during signal transmission, interference such as common-mode voltage and noise current generated by the high-voltage side circuit cannot be conducted back to the low-voltage side main control module 101 through the ground wire or other signal lines.

[0088] For example, when the main control module 101 outputs a PWM signal, this signal first enters the input side of the isolated signal transmission module 106. The conversion mechanism inside the module will copy this timing signal without distortion to the output side, and then provide it to the power drive module 102. Throughout the process, there is no ohmic contact between the output pin of the main control module 101 and the input pin of the power drive module 102; they belong to two independent ground planes.

[0089] In the above embodiment, by adding an isolated signal transmission module 106 between the main control module 101 and the power drive module 102, the reverse propagation path of the high-frequency switching noise generated by the power drive module 102 to the main control module 101 is effectively blocked. Therefore, the working environment of the main control module 101 is purified, and the integrity and accuracy of its output drive control signal are guaranteed, avoiding valve opening control deviation caused by signal distortion.

[0090] In some embodiments, the isolated signal transmission module 106 includes: The optocoupler, including its LED anode and cathode, is connected to the output circuit of the main control module 101; the collector and emitter of the photodetector in the optocoupler are connected to the input circuit of the power drive module 102; and / or The digital isolator has its low-voltage control circuit connected to the output circuit of the main control module 101, and its high-voltage execution circuit connected to the input circuit of the power drive module 102.

[0091] In some embodiments, the optocoupler is replaced by a magnetically isolated device.

[0092] In some embodiments, the electronic expansion valve actuation device further includes: An isolation amplifier is used to input analog signals that control the operation of the main control module 101, and its output is connected to the signal input terminal of the main control module 101.

[0093] In this embodiment, the electronic expansion valve drive device of the present invention typically needs to receive instructions from the chiller main control system to determine the target opening degree of the electronic expansion valve. These instructions are usually transmitted over long distances in the form of standard industrial analog signals, such as 4-20mA current loop signals. However, during long-distance transmission, or in a computer room environment where multiple devices operate concurrently, signal cables are susceptible to electromagnetic interference, and there may be a difference in grounding potential between the signal source (chiller main control system) and the drive device, forming a ground loop. These factors can all cause common-mode interference or noise to be coupled into the analog signal.

[0094] If this contaminated analog signal is directly input to the main control module 101, the analog-to-digital converter (ADC) inside the main control module 101 will convert the noise along with the signal during signal acquisition, causing the parsed command value to deviate from the true command. For example, a command signal that should be 10mA may be misread as 10.5mA. This deviation will cause the main control module 101 to calculate the wrong number of drive steps, ultimately resulting in the electronic expansion valve opening not accurately matching the cooling demand, affecting the temperature control accuracy of the entire system.

[0095] An isolation amplifier is connected in series between the external signal source and the main control module 101 to form a protective barrier for the signal input. Specifically, the input terminal of the isolation amplifier is used to input the analog signal controlling the operation of the main control module 101, for example, connected to a terminal block for receiving external 4-20mA signals. The output terminal of the isolation amplifier is connected to the signal input terminal of the main control module 101 (e.g., the ADC pin on the main control module 101 for analog-to-digital conversion).

[0096] In this way, the isolation amplifier physically disconnects the ground connection between its input and output terminals. When used in this device, the ground wire of its input terminal is connected to the reference ground of the external signal, while the ground wire of its output terminal is connected to the digital ground of the main control module 101.

[0097] This embodiment introduces an isolation amplifier. When an external 4-20mA analog signal enters the drive unit, it is first received by the isolation amplifier. The isolation amplifier utilizes its internal non-contact signal coupling mechanism to replicate the effective information of the signal to its output, while simultaneously blocking all interference signals carried on the input signal line, such as common-mode noise and ground loop interference, that are inconsistent with the ground plane of the main control module 101, outside the isolation barrier. Thus, the final signal reaching the ADC pin of the main control module 101 is a pure, interference-free analog voltage signal that is completely consistent with the internal digital ground reference of the device. This scheme ensures the accuracy of the command source acquired by the main control module 101. Even in harsh external electromagnetic environments or with ground potential differences, it guarantees accurate parsing of control commands, thereby providing the most original and reliable data foundation for subsequent stall detection, motor drive, and other control actions, ensuring the control accuracy and operational stability of the entire drive unit from the source.

[0098] In one embodiment, such as Figure 5As shown, when the isolated signal transmission module 106 is an optocoupler, a digital isolator, and the first voltage value is a DC voltage of 24V, the input terminal of the isolation amplifier is used to input a 4-20mA analog signal, and the power drive module 102 is a stepper motor drive chip, the electronic expansion valve drive device uses an optocoupler and a digital isolator to achieve signal isolation, and uses an isolation amplifier to process the analog signal.

[0099] In some embodiments, a refrigeration device is provided, comprising: Electronic expansion valve; The electronic expansion valve drive device, as described in any of the above embodiments, is used to drive the electronic expansion valve to operate.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electronic expansion valve driving device, characterized in that, include: Main control module; A power drive module, connected to the main control module, is used to drive the motor inside the electronic expansion valve; A stall detection module, connected to the main control module or the power drive module, is used to determine the operating status of the motor by monitoring one or more operating parameters of the motor during the process of the power drive module driving the motor. as well as Since the motor is in a stalled state, the power drive module is controlled to stop driving the motor.

2. The electronic expansion valve driving device according to claim 1, characterized in that, The operating parameters include the back electromotive force of the motor.

3. The electronic expansion valve driving device according to claim 1, characterized in that, The electronic expansion valve driving device also includes: The fault alarm module is connected to the stall detection module and is used to output the first alarm information when the motor is in a stalled operating state. The first alarm information includes local alarm information and / or remote alarm information.

4. The electronic expansion valve driving device according to claim 3, characterized in that, The operating parameters include the drive current of the motor and / or the motor temperature; The stall detection module is also used for: Based on the drive current being greater than or equal to a preset current threshold or the motor temperature being greater than a preset rated temperature, perform at least one of the following operations: Control the power drive module to stop outputting the drive signal that drives the motor; The fault alarm module is controlled to output a second alarm message.

5. The electronic expansion valve driving device according to any one of claims 1 to 4, characterized in that, The electronic expansion valve drive device also includes: An isolated power supply module, wherein the input terminal of the isolated power supply module is used to input a first DC voltage, the first output terminal of the isolated power supply module is connected to the main control module and the stall detection module respectively, and is used to provide a second DC voltage to the main control module, and the second output terminal of the isolated power supply module is connected to the power drive module, and is used to provide a third DC voltage to the main control module; Wherein, the first DC voltage is greater than the third DC voltage, and the third DC voltage is greater than the second DC voltage.

6. The electronic expansion valve driving device according to claim 5, characterized in that, The electronic expansion valve driving device also includes: A transient suppression diode is disposed at the input terminal of the isolated power supply module; and / or A common-mode inductor is located at the input terminal of the isolated power supply module.

7. The electronic expansion valve driving device according to claim 5, characterized in that, The electronic expansion valve driving device also includes: An isolated signal transmission module is connected in series between the main control module and the power drive module to isolate the signals transmitted between the main control module and the power drive module.

8. The electronic expansion valve driving device according to claim 7, characterized in that, The isolated signal transmission module includes: An optocoupler, wherein the LED anode and the LED cathode of the optocoupler are connected to the output circuit of the main control module; and the collector and the emitter of the photodetector in the optocoupler are connected to the input circuit of the power drive module; and / or A digital isolator, wherein the low-voltage control circuit of the digital isolator is connected to the output circuit of the main control module, and the high-voltage execution circuit of the digital isolator is connected to the input circuit of the power drive module.

9. The electronic expansion valve driving device according to any one of claims 1 to 4, characterized in that, The electronic expansion valve driving device also includes: An isolation amplifier is provided, the input of which is used to input analog signals that control the operation of the main control module, and the output of which is connected to the signal input of the main control module.

10. A refrigeration device, characterized in that, include: Electronic expansion valve; The electronic expansion valve driving device according to any one of claims 1 to 9, wherein the electronic expansion valve driving device is used to drive the electronic expansion valve to operate.

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