Electronic soft start control method for single-phase asynchronous motor

Abstract

The invention relates to the technical field of single-phase asynchronous motors, and discloses an electronic soft start control method for a single-phase asynchronous motor, which accurately controls the start process of the motor by combining an MCU (Microprogrammed Control Unit) with an electricity metering chip and a silicon controlled rectifier technology. After the system is powered on, the MCU control unit firstly carries out initialization and reads initial circuit parameters collected by the electricity metering chip, and whether starting conditions are met or not is judged based on the parameters. Once the starting condition is confirmed to be met, the MCU sequentially triggers the auxiliary silicon controlled rectifiers to switch on the starting winding and then triggers the main silicon controlled rectifiers to switch on the main winding, so that the motor enters a running state. As the motor reaches a stable operation state, the MCU control unit closes the auxiliary silicon controlled rectifier to reduce unnecessary energy consumption, and adaptively adjusts the conduction time of the starting winding according to the actual load condition, thereby ensuring that the whole starting process is stable and efficient.

Description

Technical Field

[0001] This application relates to the technical field of single-phase asynchronous motors, and more specifically, to an electronic soft-start control method for single-phase asynchronous motors. Background Art

[0002] In modern household appliances such as air conditioners, refrigerators, and industrial equipment, single-phase asynchronous motors are widely used due to their simple structure and cost-effectiveness. However, such motors cannot self-start and usually require additional starting devices to provide starting current to enable them to reach normal operating speeds. Traditional starting methods mainly include PTC starters and hammer starters. The PTC starter utilizes the characteristic that the resistance of a positive temperature coefficient thermistor rapidly increases due to current passing through at the initial stage of starting, thereby automatically cutting off the starting winding circuit. Although simple starting control is achieved, it has problems such as slow response time, continuous heat generation after starting resulting in energy waste, and its performance is easily affected by the ambient temperature. On the other hand, the hammer starter relies on the opening and closing of mechanical contacts to control the connection and disconnection of the starting winding circuit. This method has low reliability and uncontrollable on-off speed due to mechanical wear and aging problems, and also lacks the ability to make intelligent adjustments according to load changes.

[0003] With the increasing demand for energy conservation, high efficiency, and intelligent control, traditional starting methods have become difficult to meet the current market requirements. Especially in terms of improving energy efficiency, extending equipment life, and enhancing system stability, the existing technologies are insufficient. Therefore, there is an urgent need for a new starting method that can achieve more precise control, higher energy efficiency, and stronger adaptability. It is precisely based on such market demands and technical challenges that this application proposes an electronic soft-start control method for single-phase asynchronous motors. Summary of the Invention

[0004] In response to the challenges encountered by single-phase asynchronous motors during the starting process, especially the problems of slow response speed, high energy consumption, mechanical wear, and lack of intelligent adjustment ability existing in traditional starting methods (such as PTC starters and hammer starters), this application proposes an electronic soft-start control method for single-phase asynchronous motors.

[0005] According to one aspect of the present application, an electronic soft start control method for a single-phase asynchronous motor is provided, including: when the system is powered on, the MCU control unit is initialized and reads the initial circuit parameters collected by the electric metering chip, and determines whether the start condition is satisfied based on the initial circuit parameters; after determining that the start condition is satisfied, the MCU control unit triggers the conduction of the auxiliary thyristor to connect the start winding of the single-phase asynchronous motor, and then the MCU control unit triggers the conduction of the main thyristor to connect the main winding of the single-phase asynchronous motor so that the single-phase asynchronous motor starts to operate; the MCU control unit turns off the auxiliary thyristor to disconnect the start winding and the main thyristor remains in the conduction state, wherein the MCU control unit adaptively adjusts the conduction time of the start winding based on the load condition.

[0006] In a possible implementation, when the system is powered on, the MCU control unit is initialized and reads the initial circuit parameters collected by the electric metering chip, and determines whether the start condition is satisfied based on the initial circuit parameters, including: reading the effective voltage value and the effective current value from the voltage register and the current register of the electric metering chip; determining whether the effective voltage value is within a preset range to obtain a voltage check result; determining whether the effective current value is less than or equal to the current threshold value to obtain a current check result; in response to the voltage check result and the current check result being compliant, it is determined that the start condition is satisfied.

[0007] In a possible implementation, when the system is powered on, the MCU control unit is initialized and reads the initial circuit parameters collected by the electric metering chip, and determines whether the start condition is satisfied based on the initial circuit parameters, further including: if the voltage check result is a failure, the system will stay in the initialization failure state and blink the fault LED; if the current check result is a failure, the system enters the fault lock state and blinks the fault LED.

[0008] In a possible implementation, the MCU control unit adaptively adjusts the conduction time of the start winding based on the load condition, including: receiving the effective current value from the electric metering chip; based on the effective current value, determining whether to turn off the auxiliary thyristor to disconnect the start winding.

[0009] In a possible implementation, based on the effective current value, determining whether to turn off the auxiliary thyristor to disconnect the start winding, including: determining whether the effective current value is less than a first preset threshold; when the effective current value is less than the first preset threshold, it is confirmed to turn off the auxiliary thyristor to disconnect the start winding.

[0010] In a possible implementation, based on the effective value of the current, determining whether to turn off the auxiliary thyristor to disconnect the starting winding includes: calculating the falling rate of the effective value of the current; determining whether the falling rate of the effective value of the current is less than a second preset threshold, and when the falling rate of the effective value of the current is less than the second preset threshold, confirming to turn off the auxiliary thyristor to disconnect the starting winding.

[0011] In a possible implementation, based on the effective value of the current, determining whether to turn off the auxiliary thyristor to disconnect the starting winding includes: determining whether the conduction time exceeds the shortest starting winding conduction time; after determining that the conduction time exceeds the shortest starting winding conduction time, determining whether the effective value of the current is less than a first preset threshold and whether the falling rate of the effective value of the current is less than a second preset threshold, and if the conditions are met, confirming to turn off the auxiliary thyristor to disconnect the starting winding.

[0012] In a possible implementation, the first preset threshold and the second preset threshold are obtained by dynamically adjusting the first initial preset threshold and the second initial preset threshold, and the dynamic adjustment is performed based on the time period during which the conduction time exceeds the shortest starting winding conduction time, the effective value of the current at the shortest starting winding conduction time, and the falling rate of the effective value of the current.

[0013] In a possible implementation, the dynamic adjustment is performed based on the time period during which the conduction time exceeds the shortest starting winding conduction time, the effective value of the current at the shortest starting winding conduction time, and the falling rate of the effective value of the current, and includes: determining the first initial preset threshold and the second initial preset threshold; calculating the time period during which the conduction time exceeds the shortest starting winding conduction time, the effective value of the current at the shortest starting winding conduction time, and the falling rate of the effective value of the current; based on the first initial preset threshold, the second initial preset threshold, the time period during which the conduction time exceeds the shortest starting winding conduction time, the effective value of the current at the shortest starting winding conduction time, and the falling rate of the effective value of the current, calculating a tolerance coefficient and a response standard deviation; using the tolerance coefficient and the response standard deviation as adaptive threshold adjustment coefficients to adjust the first initial preset threshold and the second initial preset threshold to obtain the first preset threshold and the second preset threshold.

[0014] Compared with the prior art, the electronic soft-start control method for single-phase asynchronous motors provided by this application uses an MCU control unit combined with an electricity metering chip and thyristor technology to precisely control the motor startup process. Specifically, after the system is powered on, the MCU control unit first initializes and reads the initial circuit parameters collected by the electricity metering chip, and determines whether the startup conditions are met based on these parameters. Once it is confirmed that the startup conditions are met, the MCU control unit will sequentially trigger the auxiliary thyristor to turn on the startup winding, and then trigger the main thyristor to turn on the main winding, enabling the motor to enter the running state. As the motor reaches a stable operating state, the MCU control unit will turn off the auxiliary thyristor to reduce unnecessary energy consumption, and adaptively adjust the conduction time of the startup winding according to the actual load conditions to ensure that the entire startup process is both smooth and efficient. In addition, by integrating various protection functions such as overcurrent, overvoltage, and over-temperature, the safety and reliability of the system are further enhanced. Description of the Drawings

[0015] By describing the embodiments of this application in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of this application will become more obvious. The drawings are used to provide a further understanding of the embodiments of this application, and constitute a part of the specification. Together with the embodiments of this application, they are used to explain this application and do not constitute a limitation to this application. In the drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 The figure illustrates a schematic flowchart of an electronic soft-start control method for a single-phase asynchronous motor according to an embodiment of this application.

[0017] Figure 2 The figure illustrates a schematic flowchart of the electronic soft-start control method for a single-phase asynchronous motor according to an embodiment of this application, where after the system is powered on, the MCU control unit initializes and reads the initial circuit parameters collected by the electricity metering chip and determines whether the startup conditions are met based on the initial circuit parameters.

[0018] Figure 3 The figure illustrates a schematic block diagram of the principle of a soft-start control circuit for a single-phase asynchronous motor according to an embodiment of this application.

[0019] Figure 4 The figure illustrates a schematic flowchart of the electronic soft-start control method for a single-phase asynchronous motor according to an embodiment of this application, where the MCU control unit adaptively adjusts the conduction time of the startup winding based on the load conditions.

[0020] Figure 5 The figure illustrates a schematic flowchart of the electronic soft-start control method for a single-phase asynchronous motor according to an embodiment of this application, where based on the effective value of the current, it is determined whether to turn off the auxiliary thyristor to disconnect the startup winding.

[0021] Figure 6 Illustrated is a schematic flowchart of another embodiment of an electronic soft - start control method for a single - phase asynchronous motor according to an embodiment of the present application, which determines whether to turn off the auxiliary thyristor to disconnect the starting winding based on the effective value of the current.

[0022] Figure 7 Illustrated is a schematic flowchart of yet another embodiment of an electronic soft - start control method for a single - phase asynchronous motor according to an embodiment of the present application, which determines whether to turn off the auxiliary thyristor to disconnect the starting winding based on the effective value of the current. Detailed implementation manners

[0023] Hereinafter, exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein.

[0024] Figure 1 Illustrated is a schematic flowchart of an electronic soft - start control method for a single - phase asynchronous motor according to an embodiment of the present application. As Figure 1 shown, the present application provides an electronic soft - start control method for a single - phase asynchronous motor, including: S1, when the system is powered on, the MCU control unit initializes and reads the initial circuit parameters collected by the electricity metering chip, and determines whether the start condition is satisfied based on the initial circuit parameters; S2, after determining that the start condition is satisfied, the MCU control unit triggers the auxiliary thyristor to conduct to connect the starting winding of the single - phase asynchronous motor, and then the MCU control unit triggers the main thyristor to conduct to connect the main winding of the single - phase asynchronous motor so that the single - phase asynchronous motor starts to operate; S3, the MCU control unit turns off the auxiliary thyristor to disconnect the starting winding and the main thyristor remains in the conducting state, wherein the MCU control unit adaptively adjusts the conducting time of the starting winding based on the load condition.

[0025] Specifically, after the system is powered on, the MCU control unit first performs an initialization process and reads the initial circuit parameters from the integrated electricity metering chip, including the effective value of voltage and the effective value of current. Based on these parameters, the MCU control unit can accurately determine whether the start condition is satisfied. This pre - inspection mechanism ensures that the motor starts only under safe conditions, avoiding equipment damage caused by power problems.

[0026] In one embodiment, as Figure 2As shown, when the system is powered on, the MCU control unit initializes and reads the initial circuit parameters collected by the electricity metering chip, and determines whether the startup conditions are met based on the initial circuit parameters, including: S11, reading the effective voltage value and the effective current value from the voltage register and the current register of the electricity metering chip; S12, determining whether the effective voltage value is within a preset range to obtain a voltage check result; S13, determining whether the effective current value is less than or equal to the current threshold value to obtain a current check result; S14, in response to the voltage check result and the current check result being compliant, determining that the startup conditions are met.

[0027] In one embodiment, when the system is powered on, the MCU control unit initializes and reads the initial circuit parameters collected by the electricity metering chip, and determines whether the startup conditions are met. It further includes: if the voltage check result is a failure, the system will stay in the initialization failure state and blink the fault LED; if the current check result is a failure, the system enters the fault lock state and blinks the fault LED.

[0028] Specifically, if the voltage is too low or too high, it may cause the motor to fail to start properly or even be damaged; similarly, if the current is too large, it may be due to a short circuit or other faults in the circuit, and directly starting the motor may pose a danger. Therefore, by accurately measuring these parameters, potential risks can be effectively prevented. The MCU control unit will determine whether the measured effective voltage value is within the preset safe range to obtain the voltage inspection result. This inspection aims to ensure that the motor starts under safe voltage conditions and avoid equipment damage or potential safety hazards caused by abnormal voltage. In a specific embodiment, the range is 200V to 240V. If the detected voltage is lower than 200V or higher than 240V, it is considered that the voltage inspection fails, and the system will enter the fault lock state and flash the fault LED to prompt the user to pay attention. At the same time, the MCU control unit will also determine whether the effective current value is less than or equal to the set current threshold value to obtain the current inspection result. The current threshold value is usually determined based on the motor specifications and load characteristics to prevent the motor from starting under high current conditions. This not only helps protect the motor from overload damage but also reduces the impact of power grid fluctuations on other electrical appliances. In a specific embodiment, for a motor with a rated current of 5A, the current threshold value can be set to 1.5 times the motor's rated current, that is, 7.5A. This means that during the startup phase, if the effective current value read by the MCU control unit from the electricity metering chip is less than or equal to 7.5A, it is considered that one of the startup conditions is met; conversely, if the effective current value exceeds 7.5A, it indicates that there may be abnormal conditions in the circuit, such as short circuit, overload, etc. At this time, the system should stop the startup process and trigger the corresponding protection mechanism, such as flashing the fault LED to warn the user and entering the fault lock state to wait for further inspection or repair. Here, those skilled in the art should be aware that the above values are only examples and do not constitute specific limitations of this application.

[0029] Only when both the voltage inspection result and the current inspection result meet the requirements will the MCU control unit further determine that the startup conditions are satisfied. This means that only when it is confirmed that the power supply voltage is stable and the current is within the safe range will the system allow the motor to start. This dual-check mechanism greatly improves the reliability and safety of the system, ensuring that the motor starts under the best conditions every time.

[0030] Once it is determined that the starting conditions are met, the MCU control unit will trigger the conduction of the auxiliary thyristor, thus connecting the starting winding of the motor and providing additional starting torque for the motor. The role of the starting winding at this stage is crucial as it helps the motor overcome the static inertia and quickly reach the operating speed. It should be noted that the conduction time of the starting winding is not fixed but is adaptively adjusted according to the real-time monitored load conditions. This means that when the motor load is light, the starting winding may only need to work briefly to complete the task; while when the load is heavy, the starting winding requires longer support to ensure the smooth start of the motor. In this way, not only the starting efficiency is improved, but also unnecessary energy consumption is reduced.

[0031] With the successful connection of the starting winding, the MCU control unit then triggers the conduction of the main thyristor, connecting the main winding of the motor as well, and thus enabling the motor to start normal operation. At this time, the motor gradually accelerates until it reaches a stable operating state, and the task of the starting winding has been basically completed. To further improve the energy efficiency of the system, the MCU control unit will turn off the auxiliary thyristor after the motor enters the stable operating state, cutting off the power supply to the starting winding to avoid its continuous power consumption. This design not only significantly reduces the energy consumption of the system but also solves the problem of energy waste caused by the long-term heating of traditional PTC starters. Here, for the sake of easy understanding, a schematic principle block diagram of a soft start control circuit for a single-phase asynchronous motor is also provided for the above-mentioned embodiment, as Figure 3 shown.

[0032] In particular, considering that for a single-phase asynchronous motor, such as a compressor motor, the required auxiliary starting torque and starting time during startup are affected by various factors, the most important of which is the load size. In the case of light-load startup, for example, when the system pressure is low before the compressor starts or the inertia of the motor itself is small, the startup is relatively easy and the required startup assistance time is short; while in the case of heavy-load startup, such as when the compressor restarts shortly after shutdown resulting in a high system pressure, or when the grid voltage is low, the motor requires a larger starting torque and a longer assistance time to reach the stable operating speed. Traditional PTC or fixed-time starters, due to their inability to distinguish these situations, usually design according to the worst-case scenario or adopt a compromise fixed time, which may lead to energy waste under light loads or startup failures under heavy loads. To solve this problem, the MCU control unit no longer uses a fixed conduction time for the starting winding but instead utilizes an electricity metering chip to monitor the root mean square (RMS) current of the motor. Here, the electricity metering chip can measure the current flowing through the motor winding in real time and periodically transmit this data to the MCU control unit through a communication interface (such as SPI or I2C). By analyzing the changing trends of these parameters to determine whether the motor has successfully started and reached a state close to stable operation, once the judgment is successful, the auxiliary thyristor is immediately turned off to cut off the starting winding.

[0033] In one embodiment, as Figure 4 shown, the MCU control unit adaptively adjusts the conduction time of the starting winding based on the load condition, including: S31, receiving the effective current value from the electricity metering chip; S32, determining whether to turn off the auxiliary thyristor to disconnect the starting winding based on the effective current value.

[0034] In one embodiment, as Figure 5 shown, determining whether to turn off the auxiliary thyristor to disconnect the starting winding based on the effective current value includes: S321, determining whether the effective current value is less than a first preset threshold; S322, when the effective current value is less than the first preset threshold, confirming to turn off the auxiliary thyristor to disconnect the starting winding. That is, if the detected effective current value continuously remains lower than the first preset threshold (for example, 3A, of course, the above is only an example, and the first preset threshold is set and adjusted based on experience or experiments, and the present application does not specifically limit it), it indicates that the motor has obtained sufficient starting torque. At this time, the MCU control unit will trigger the auxiliary thyristor to close, thereby disconnecting the starting winding and avoiding unnecessary energy consumption. This strategy ensures that the starting winding only operates when necessary, improving the energy efficiency of the system.

[0035] However, relying solely on the effective current value may not be sufficient to comprehensively reflect the actual state of the motor. Therefore, the present application further introduces the concept of the rate of decrease of the effective current value. In another embodiment, as Figure 6 shown, determining whether to turn off the auxiliary thyristor to disconnect the starting winding based on the effective current value includes: S323, calculating the rate of decrease of the effective current value; S324, determining whether the rate of decrease of the effective current value is less than a second preset threshold. When the rate of decrease of the effective current value is less than the second preset threshold, confirm to turn off the auxiliary thyristor to disconnect the starting winding. Specifically, when the current rapidly decreases during the motor acceleration process, it indicates that the motor is smoothly entering the stable operation state. At this time, even if the effective current value has not reached the first preset threshold, but its rate of decrease is less than a certain preset second threshold (for example, 0.5A / s, of course, the above is only an example, and the second preset threshold is set and adjusted based on experience or experiments, and the present application does not specifically limit it), the MCU control unit will also decide to turn off the auxiliary thyristor. This method can more accurately capture the state change of the motor and make a timely response, preventing starting failure or low efficiency caused by cutting off the starting winding too early or too late.

[0036] Furthermore, the present application also takes into account the importance of the shortest conduction time of the starting winding, that is, regardless of other conditions, the starting winding should at least remain conductive for a period of time to ensure that the motor has enough time to overcome the initial resistance. A shortest conduction time of the starting winding is set (to ensure that the motor has enough time to start, for example, 1 s. Similarly, it can be set and adjusted based on experience or based on experiments). After this time, the current threshold or rate of change is used for judgment. In another embodiment, as Figure 7 shown, based on the effective value of the current, determining whether to turn off the auxiliary thyristor to disconnect the starting winding includes: S325, determining whether the conduction time exceeds the shortest conduction time of the starting winding; S326, after determining that the conduction time exceeds the shortest conduction time of the starting winding, determining whether the effective value of the current is less than a first preset threshold and whether the rate of decrease of the effective value of the current is less than a second preset threshold. If the conditions are met, it is confirmed to turn off the auxiliary thyristor to disconnect the starting winding. Here, the first preset threshold and the second preset threshold are set and adjusted based on experience or based on experiments.

[0037] Furthermore, in the case where the conduction time exceeds the shortest conduction time of the starting winding, based on the current continuity of the starting winding under electromagnetic induction, there is obviously a negative correlation between the conduction time of the starting winding and the decrease in the effective value of the current. Therefore, both the first preset threshold corresponding to the effective value of the current and the second preset threshold corresponding to the rate of decrease of the effective value of the current will change relative to the above-mentioned preset thresholds, for example, denoted as the first initial preset threshold and the second initial preset threshold change, and on the other hand, this is obviously also related to the time period during which the conduction time exceeds the shortest conduction time of the starting winding, for example, denoted as related. Therefore, determining the first preset threshold and the second preset threshold based on experience or based on experiments is obviously not the optimal solution. Therefore, in a preferred embodiment, the first preset threshold and the second preset threshold are obtained by dynamically adjusting the first initial preset threshold and the second initial preset threshold, and the dynamic adjustment is performed based on the time period during which the conduction time exceeds the shortest conduction time of the starting winding, the effective value of the current at the shortest conduction time of the starting winding, and the rate of decrease of the effective value of the current.

[0038] Specifically, the dynamic adjustment is performed based on the period during which the conduction time exceeds the shortest starting winding conduction time, the effective current value at the shortest starting winding conduction time, and the decreasing rate of the effective current value, and includes: First, determine a first initial preset threshold and a second initial preset threshold (here, the threshold determined based on experience or experiment is used as the initial preset threshold). Then, calculate the period during which the conduction time exceeds the shortest starting winding conduction time, the effective current value at the shortest starting winding conduction time, and the decreasing rate of the effective current value, and calculate a tolerance coefficient and a response standard deviation based on the first initial preset threshold, the second initial preset threshold, the period during which the conduction time exceeds the shortest starting winding conduction time, the effective current value at the shortest starting winding conduction time, and the decreasing rate of the effective current value.

[0039] Specifically, denote the effective current value at the shortest starting winding conduction time as , then the decreasing rate of the effective current value . Thus, the response value of the decreasing rate of the effective current value relative to the effective current value satisfies: ; where is the tolerance coefficient, is the response standard deviation.

[0040] And similarly, the relationship between the first initial preset threshold and the second initial preset threshold is: ; that is, based on the response gradient of the decreasing rate of the effective current value relative to the effective current value, is used as the power frequency offset term, and the time window detection reference attenuation between the defined preset threshold and is obtained. Thus, the tolerance coefficient and the response standard deviation can be calculated in the case where the known conduction exceeded period .

[0041] In this way, using the tolerance coefficient and the response standard deviation as the adaptive threshold adjustment coefficients to adjust the first initial preset threshold and the second initial preset threshold to obtain the first preset threshold and the second preset threshold: .

[0042] That is, the response standard deviation is used as the strong coupling-related threshold decay term that continues with the conduction time, and the tolerance coefficient is used as the environmental compensation to compensate for the threshold dynamic misjudgment caused by the negative regulation of the threshold decay. In this way, the quantifiable parameter time-domain - parameter-domain joint analysis of the first preset threshold and the second preset threshold is achieved, thus avoiding the inaccuracy that may be brought about by empirical determination and the increased burden brought about by experimental determination.

[0043] In summary, the electronic soft start control method for a single-phase asynchronous motor provided in this application uses an MCU control unit in combination with an electric metering chip and thyristor technology to precisely control the starting process of the motor. Specifically, after the system is powered on, the MCU control unit first initializes and reads the initial circuit parameters collected by the electric metering chip, and judges whether the starting conditions are met based on these parameters. Once it is confirmed that the starting conditions are met, the MCU control unit will sequentially trigger the auxiliary thyristor to connect the starting winding, and then trigger the main thyristor to connect the main winding, so that the motor enters the running state. As the motor reaches the stable operating state, the MCU control unit will turn off the auxiliary thyristor to reduce unnecessary energy consumption, and adaptively adjust the conduction time of the starting winding according to the actual load conditions to ensure that the entire starting process is both smooth and efficient. In addition, by integrating multiple protection functions such as overcurrent, overvoltage, and overheating, the safety and reliability of the system are further enhanced.

[0044] The basic principles of this application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, advantages, effects, etc. mentioned in this application are only examples and not limitations. It cannot be considered that these advantages, advantages, effects, etc. are essential for each embodiment of this application. In addition, the above-disclosed specific details are only for the purposes of illustration and easy understanding, rather than limitations. These details do not limit this application to necessarily adopt the above specific details to implement.

[0045] The flowcharts of the methods involved in this application are only illustrative examples and do not intend to require or imply that the connection, arrangement, and configuration must be carried out in the manner shown in the flowchart. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any way. Words such as "including", "comprising", "having", etc. are open-ended words, meaning "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the word "and / or", and can be used interchangeably with it, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0046] It should also be noted that in the method of this application, each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of this application.

[0047] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Thus, the present application is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0048] The above description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although numerous example aspects and embodiments have been discussed above, those skilled in the art will recognize some variations, modifications, alterations, additions, and subcombinations thereof.

Claims

1. An electronic soft start control method for a single-phase asynchronous motor, characterized in that: include: When the system is powered on, the MCU control unit performs initialization and reads the initial circuit parameters collected by the electricity metering chip and determines whether the startup conditions are met based on the initial circuit parameters; After determining that the starting conditions are met, the MCU control unit triggers the auxiliary thyristor to turn on to connect the starting winding of the single-phase asynchronous motor, and then the MCU control unit triggers the main thyristor to turn on the main winding of the single-phase asynchronous motor to start the single-phase asynchronous motor; the MCU control unit turns off the auxiliary thyristor to disconnect the starting winding and the main thyristor remains in the on state, wherein the MCU control unit adaptively adjusts the conduction time of the starting winding based on the load conditions.

2. The electronic soft start control method for a single-phase asynchronous motor according to claim 1, characterized in that: When the system is powered on, the MCU control unit is initialized and reads the initial circuit parameters collected by the electricity metering chip and determines whether the startup conditions are met based on the initial circuit parameters, including: reading the voltage effective value and the current effective value from the voltage register and the current register of the electricity metering chip; determining whether the voltage effective value is within a preset range to obtain a voltage check result; determining whether the current effective value is less than or equal to a current threshold value to obtain a current check result; and in response to the voltage check result and the current check result being in compliance with the requirements, determining that the startup conditions are met.

3. The electronic soft start control method for a single-phase asynchronous motor according to claim 2, characterized in that: When the system is powered on, the MCU control unit performs initialization and reads the initial circuit parameters collected by the electricity metering chip and determines whether the startup conditions are met based on the initial circuit parameters. It also includes: if the voltage check result is a failure, the system will stay in the initialization failure state and flash the fault LED; if the current check result is a failure, the system enters the fault lock state and flashes the fault LED.

4. The electronic soft start control method for a single-phase asynchronous motor according to claim 1, characterized in that: The MCU control unit adaptively adjusts the conduction time of the start winding based on the load condition, including: receiving the effective value of the current from the electric metering chip; and judging whether to turn off the auxiliary thyristor to disconnect the start winding based on the effective value of the current.

5. The electronic soft start control method for a single-phase asynchronous motor according to claim 4, characterized in that: Based on the effective value of the current, determine whether to turn off the auxiliary thyristor to disconnect the starting winding, including: determining whether the effective value of the current is less than a first preset threshold; when the effective value of the current is less than the first preset threshold, confirm to turn off the auxiliary thyristor to disconnect the starting winding.

6. The electronic soft start control method for a single-phase asynchronous motor according to claim 4, characterized in that: Based on the effective value of the current, determine whether to turn off the auxiliary thyristor to disconnect the starting winding, including: calculating the decreasing rate of the effective value of the current; determining whether the decreasing rate of the effective value of the current is less than a second preset threshold, and when the decreasing rate of the effective value of the current is less than the second preset threshold, confirm to turn off the auxiliary thyristor to disconnect the starting winding.

7. The electronic soft start control method for a single-phase asynchronous motor according to claim 4, characterized in that: Based on the effective value of the current, determine whether to turn off the auxiliary thyristor to disconnect the starting winding, including: determining whether the conduction time exceeds the shortest start winding conduction time; after determining that the conduction time exceeds the shortest start winding conduction time, determine whether the effective value of the current is less than a first preset threshold and whether the rate of decrease of the effective value of the current is less than a second preset threshold; if the conditions are met, confirm that the auxiliary thyristor is turned off to disconnect the starting winding.

8. The electronic soft start control method for a single-phase asynchronous motor according to claim 7, characterized in that: The first preset threshold and the second preset threshold are obtained by dynamically adjusting the first initial preset threshold and the second initial preset threshold, and the dynamic adjustment is performed based on the time period when the conduction time exceeds the shortest starting winding conduction time, the effective value of the current at the shortest starting winding conduction time, and the decreasing rate of the effective value of the current.

9. The electronic soft start control method for a single-phase asynchronous motor according to claim 8, characterized in that: The dynamic adjustment is performed based on the time period when the conduction time exceeds the shortest start winding conduction time, the effective value of the current when the conduction time is the shortest start winding, and the rate of decrease of the effective value of the current, including: determining a first initial preset threshold and a second initial preset threshold; calculating the time period when the conduction time exceeds the shortest start winding conduction time, the effective value of the current when the conduction time is the shortest start winding, and the rate of decrease of the effective value of the current; based on the first initial preset threshold, the second initial preset threshold, the time period when the conduction time exceeds the shortest start winding conduction time, the effective value of the current when the conduction time is the shortest start winding, and the rate of decrease of the effective value of the current, calculate the tolerance coefficient and the response standard deviation; use the tolerance coefficient and the response standard deviation as adaptive threshold adjustment coefficients to adjust the first initial preset threshold and the second initial preset threshold to obtain the first preset threshold and the second preset threshold.

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