Single-phase asynchronous motor starting control circuit with anomaly detection

Abstract

This application relates to the field of single-phase asynchronous motor technology, and discloses a single-phase asynchronous motor starting control circuit with anomaly detection. The circuit includes an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit. The main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit. The MCU control unit executes control logic, which not only precisely controls the on and off timing of the main and secondary thyristors to optimize the motor starting process and reduce starting shock, but also judges abnormal states based on real-time current and voltage data provided by the electrical metering chip and quickly takes protective measures when an anomaly is detected. Furthermore, it records key operating parameters when an abnormal state occurs, providing a basis for subsequent fault analysis, greatly simplifying the fault diagnosis process and reducing maintenance costs.

Description

Technical Field

[0001] This application relates to the field of single-phase asynchronous motor technology, and more specifically, to a single-phase asynchronous motor starting control circuit with anomaly detection. Background Technology

[0002] In the starting process of single-phase asynchronous motors, traditional starting methods mainly rely on PTC thermal starters or counterweight mechanical starters. Although these methods are simple to implement, they have many shortcomings in practical applications, especially in terms of operational reliability and ease of maintenance.

[0003] First, traditional starters lack intelligent control mechanisms, making it difficult to dynamically adjust starting parameters according to load changes. This can easily lead to starting failures or excessive current surges, affecting grid stability. Second, these starting devices generally lack real-time monitoring capabilities, failing to effectively collect and analyze key parameters such as current, voltage, and power during motor operation. Therefore, in the event of anomalies or malfunctions, the system cannot provide effective data support, making it difficult for maintenance personnel to accurately determine the cause of the fault, resulting in difficult troubleshooting, long repair cycles, and high maintenance costs.

[0004] Furthermore, traditional starters often employ passive protection methods, such as relying on temperature changes or mechanical contact disconnection for protection. These methods are slow to respond and susceptible to environmental factors, posing significant safety hazards. For instance, PTC starters are prone to aging and failure under frequent start-stop or high-temperature environments, while the mechanical contacts of counterweight starters are prone to wear and oxidation, leading to poor contact or even complete failure. Summary of the Invention

[0005] To address the aforementioned issues, this application proposes a single-phase asynchronous motor starting control circuit with anomaly detection.

[0006] According to one aspect of this application, a single-phase asynchronous motor starting control circuit with anomaly detection is provided, comprising: an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit; the main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit; wherein the MCU control unit is used to execute control logic, the control logic including controlling the on and off timing of the main thyristor and the secondary thyristor, judging abnormal states based on real-time data from the electrical metering chip, executing protection actions, and recording key operating parameters when an abnormal state occurs.

[0007] In one possible implementation, abnormal state judgment is based on real-time data from the electricity metering chip, including: receiving real-time effective current values ​​collected by the electricity metering chip; comparing the real-time effective current values ​​with a current dynamic protection threshold to determine whether a first condition is met; and when the first condition is met, the MCU control unit shuts down the main thyristor.

[0008] In one possible implementation, the first condition is that the effective current value exceeds the current dynamic protection threshold and the duration exceeds the preset filtering time.

[0009] In one possible implementation, setting the dynamic current protection threshold includes: during the motor startup phase, obtaining a series of startup phase effective current values ​​and a series of startup phase effective voltage values ​​by high-frequency sampling of effective current and effective voltage values ​​using an electrical metering chip; identifying a peak startup current value from the series of startup phase effective current values; calculating a startup voltage value based on the timestamp of the peak startup current value and the series of startup phase effective voltage values; and calculating a reference overcurrent protection threshold based on the peak startup current value and the startup voltage value. During the motor stable operation phase, obtaining operating phase effective current and effective voltage values ​​by low-frequency sampling of effective current and effective voltage values ​​using an electrical metering chip; calculating a dynamic adjustment coefficient based on the operating phase effective current and effective voltage values; and dynamically adjusting the reference overcurrent protection threshold based on the dynamic adjustment coefficient to obtain the dynamic current protection threshold.

[0010] In one possible implementation, calculating the startup voltage value based on the timestamp of the peak startup current value and the series of startup phase effective voltage values ​​includes: based on the timestamp of the peak startup current value, extracting a short-time window near the peak of the effective voltage value from the series of startup phase effective voltage values, wherein the timestamp of the peak startup current value is located at the center of the short-time window near the peak of the effective voltage value; and calculating the average of all startup phase effective voltage values ​​in the short-time window near the peak of the effective voltage value as the startup voltage value.

[0011] In one possible implementation, calculating a reference overcurrent protection threshold based on the peak starting current value and the starting voltage value includes: calculating the reference overcurrent protection threshold based on the peak starting current value and the starting voltage value using the following formula, wherein the formula is: ;in, Peak starting current value, For the start-up voltage value, The multiple between the preset peak starting current value and the rated operating current value. To preset the overload factor, This indicates the reference overcurrent protection threshold.

[0012] In one possible implementation, the startup phase is determined. and This includes: obtaining general operational phase values. and ;based on reciprocal and The probabilistic coupling relationship between them is used to calculate the first dynamic equilibrium quantization modeling coefficient and the second dynamic equilibrium quantization modeling coefficient; based on the first dynamic equilibrium quantization modeling coefficient and the second dynamic equilibrium quantization modeling coefficient, the following is performed: A smoothing adjustment based on correlation mutations is performed to obtain a smoothing adjustment factor; based on the first dynamic equilibrium quantization modeling coefficient, the second dynamic equilibrium quantization modeling coefficient, and the smoothing adjustment factor, the following is performed: and Perform corrections to obtain the startup phase. and .

[0013] In one possible implementation, calculating the dynamic adjustment coefficient based on the effective current value and the effective voltage value of the operating phase includes: calculating the current active power value based on the effective current value and the effective voltage value of the operating phase, wherein the current active power value is the effective current value of the operating phase multiplied by the effective voltage value of the operating phase and then multiplied by the power factor; the MCU control unit obtains the rated active power value; calculating the normalized load factor based on the current active power value and the rated active power value, wherein the normalized load factor is the current active power value divided by the rated active power value; determining the load dispersion level label based on the normalized load factor; and matching the dynamic adjustment coefficient from the dynamic adjustment coefficient table based on the load dispersion level label.

[0014] In one possible implementation, the load discrete level labels include no load, very light load, medium load, rated load, and instantaneous overload.

[0015] Compared with existing technologies, the single-phase asynchronous motor starting control circuit with anomaly detection provided in this application includes an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit. The main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit. The MCU control unit executes control logic, enabling precise control of the on / off timing of the main and secondary thyristors to optimize the motor starting process and reduce starting shock. It also judges abnormal states based on real-time current and voltage data provided by the electrical metering chip and quickly takes protective measures when an anomaly is detected. Furthermore, it records key operating parameters when an abnormal state occurs, providing a basis for subsequent fault analysis, greatly simplifying the fault diagnosis process and reducing maintenance costs. Attached Figure Description

[0016] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0017] Figure 1 The figure shows a schematic block diagram of a single-phase asynchronous motor starting control circuit with anomaly detection according to an embodiment of this application.

[0018] Figure 2 The illustration shows a schematic flowchart of an abnormal state judgment based on real-time data from an electrical metering chip in a single-phase asynchronous motor start-up control circuit with abnormal detection according to an embodiment of this application.

[0019] Figure 3 The illustration shows a schematic flowchart of the setting of the current dynamic protection threshold in a single-phase asynchronous motor starting control circuit with anomaly detection according to an embodiment of this application.

[0020] Figure 4 The illustration shows a schematic flowchart of a single-phase asynchronous motor starting control circuit with anomaly detection according to an embodiment of this application, in which the starting voltage value is calculated based on the timestamp of the peak starting current value and the series of effective voltage values ​​of the starting stage.

[0021] Figure 5 The illustration shows a schematic flowchart of a single-phase asynchronous motor starting control circuit with anomaly detection according to an embodiment of this application, in which a dynamic adjustment coefficient is calculated based on the effective current value and the effective voltage value during the operating phase. Detailed Implementation

[0022] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0023] Figure 1 The diagram illustrates a schematic block diagram of a single-phase asynchronous motor starting control circuit with anomaly detection according to an embodiment of this application. Figure 1 As shown, this application provides a single-phase asynchronous motor starting control circuit with anomaly detection, including: an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit; the main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit; wherein, the MCU control unit is used to execute control logic, the control logic including controlling the on and off timing of the main thyristor and the secondary thyristor, judging abnormal states based on real-time data from the electrical metering chip, executing protection actions, and recording key operating parameters when an abnormal state occurs.

[0024] Specifically, the core of the single-phase asynchronous motor starting control circuit with anomaly detection lies in the MCU control unit. As the intelligent processing center of the entire system, its functions possess high flexibility and strong computing power. The MCU control unit is responsible for receiving and processing real-time operating data from the electricity metering chip, including parameters such as current, voltage, and power. This real-time data not only reflects the motor's operating status but also serves as an important basis for the circuit to judge abnormal states. Based on this data, the MCU control unit runs preset control logic, handling various tasks in the starting and running phases respectively. During startup, the MCU control unit provides the most suitable starting current and starting torque to the motor by controlling the on / off timing of the main and auxiliary thyristors, ensuring a smooth motor start. During the running phase, the MCU control unit continuously monitors load data and further optimizes system operating efficiency through dynamic adjustment strategies. In addition, when the MCU control unit detects abnormal conditions, such as overcurrent, overvoltage, or overheating, it executes a protection program to quickly cut off the circuit, ensuring the safe operation of the motor and circuit. As the control core, the MCU control unit also records key operating parameters, providing reliable data support for remote system diagnosis and subsequent optimization.

[0025] The primary and secondary thyristors play distinct roles in the circuit. The primary thyristor is located at a critical point in the main control circuit of the motor, and its main function is to control the on / off state of the power supply. During the startup phase, the MCU control unit triggers the primary thyristor based on real-time monitored current and voltage signals, energizing the main motor windings to provide the necessary operating conditions. Once the motor reaches a stable operating state, the primary thyristor continues to operate, maintaining the on / off control of the main circuit. If the system triggers a protection action under certain abnormal conditions, the MCU control unit will immediately shut down the primary thyristor, quickly cutting off the power supply to prevent motor overload or system damage. The secondary thyristor focuses more on the motor startup phase, temporarily connecting the motor's auxiliary starting windings to provide additional starting torque during the initial startup. Once the motor has successfully started and reached a stable speed, the secondary thyristor shuts down under the MCU's command, disconnecting the starting windings and preventing unnecessary energy consumption. The coordinated operation of the primary and secondary thyristors greatly improves the motor's startup efficiency and operational stability.

[0026] As the core module for data acquisition, the electricity metering chip is directly connected between the power supply and the load, monitoring changes in key circuit parameters in real time through high-frequency sampling technology. During startup, the current and voltage data collected by the electricity metering chip are transmitted to the MCU control unit to calculate dynamic startup parameters, including startup current thresholds and overcurrent protection thresholds. These parameters provide the basis for the MCU control unit to control the trigger angles and on / off sequences of the main and auxiliary thyristors. After the motor enters stable operation, the electricity metering chip continues to transmit the operating current and voltage parameters back to the MCU control unit through low-frequency sampling, which is used to dynamically adjust the system strategy. This dynamic sampling and adjustment method, through intelligent analysis based on real-time data, achieves significant optimization of system protection thresholds. The data provided by the electricity metering chip can also help the MCU control unit build a comprehensive load analysis model, achieve accurate load state labeling and classification, and design optimal operating strategies for different load states.

[0027] The protection circuit plays a crucial role in the starting control circuit of this single-phase asynchronous motor, designed to provide hardware-level safety assurance for the system. The protection circuit comprises various hardware components that rapidly respond to abnormal situations occurring in the system via electromagnetic means. In the system, when the MCU control unit detects emergency conditions such as overcurrent, overvoltage, overheating, or short circuits through the power metering chip, the protection circuit immediately activates, cutting off critical power supply paths to prevent the accident from escalating. Simultaneously, the protection circuit also supports setting the overload duration, enabling the system to tolerate instantaneous overload peaks for a short period to avoid false protection. This multi-layered protection mechanism, working in conjunction with the intelligent operation of the MCU control unit, significantly improves the reliability and resilience of the entire circuit.

[0028] Specifically, the control sequence for the turn-on and turn-off of the main and auxiliary thyristors includes: During the startup phase, the auxiliary thyristor is first activated to power the starting winding. At this time, the MCU control unit monitors the current, voltage, and power data in the circuit in real time through the power metering chip to determine whether the motor is in a suitable startup state. When the system determines that the load conditions and electrical parameters meet the startup requirements, the MCU control unit sends a trigger signal to the auxiliary thyristor to energize the starting winding. During this phase, the starting winding provides additional starting torque to overcome the static inertia of the motor in a stopped state and achieve initial rotor acceleration. During this period, the MCU control unit dynamically adjusts the firing angle of the auxiliary thyristor according to the current trend fed back by the power metering chip to suppress the peak value of the starting current, thereby reducing the impact on the power grid. At the same time, the MCU control unit continuously observes the enhancement level of the back electromotive force signal. When this signal indicates that the rotor has reached the critical startup speed, the operating state of the auxiliary thyristor begins to change, preparing for the subsequent switching.

[0029] As the startup process nears completion, the main thyristor enters the core of the control logic, triggered by the MCU control unit to connect the main winding for power supply. At this moment, the main winding, as the primary drive structure of the motor, takes over the initiative in system operation, switching the motor from startup mode to normal operating mode. The firing angle of the main thyristor is dynamically calculated by the MCU control unit based on historical monitoring data from the startup phase and the current load demand of the main winding. This precise control method significantly reduces pulse fluctuations during startup transition, improving overall operating efficiency. After the main thyristor is turned on, the MCU control unit gradually guides the startup winding out of operation, sending a shutdown signal to cut off the power supply to the secondary thyristor, thereby reducing energy waste caused by uninterrupted power to the startup winding.

[0030] Meanwhile, the MCU control unit will also make abnormal status judgments based on real-time data from the electricity metering chip. If an abnormal operating status is encountered, the MCU control unit will immediately shut down the main thyristor and cut off the power supply to the main winding to prevent equipment damage or further expansion of the fault.

[0031] In one embodiment, such as Figure 2 As shown, the abnormal state judgment based on real-time data from the electricity metering chip includes: S1, receiving the real-time effective current value collected by the electricity metering chip; S2, comparing the real-time effective current value with the current dynamic protection threshold to determine whether the first condition is met; S3, when it is determined that the first condition is met, the MCU control unit turns off the main thyristor.

[0032] Specifically, the real-time data acquisition capability of the electricity metering chip employs a high-frequency sampling mechanism during motor startup to accurately record instantaneous fluctuations in current and voltage, thereby capturing the peak characteristics of each electrical parameter during startup. This data is crucial for the MCU control unit to determine whether the motor is in a normal operating state. Specifically, the MCU control unit receives the real-time effective current value acquired by the electricity metering chip and compares it with a dynamic current protection threshold based on predefined anomaly detection logic. That is, it compares the real-time effective current value with the dynamic current protection threshold to determine if a first condition is met. When the first condition is met, the MCU control unit triggers the anomaly protection logic and immediately shuts down the main thyristor.

[0033] In one embodiment, the first condition is that the effective current value exceeds the dynamic current protection threshold, and the duration exceeds a preset filtering time. It should be understood that current fluctuations are normal during the operation of a single-phase asynchronous motor, including high current peaks during startup and random disturbances during operation. These disturbances may originate from short-term electrical parameter anomalies caused by external load changes, power supply fluctuations, or environmental factors. However, such short-term current fluctuations are part of the normal operation of most motors and usually do not pose a potential hazard. Without a filtering time design, such as requiring immediate protection action whenever the current exceeds the protection threshold, unnecessary shutdowns are highly likely, affecting system stability and user experience. Furthermore, relying solely on the dynamic protection threshold for judgment is insufficient, as short-term peak currents are a typical phenomenon during startup. Without time-based constraints, this could interfere with the startup process. Therefore, the requirement that the duration exceeds the preset filtering time adds an additional judgment dimension to the time axis, enabling more efficient screening of anomalies.

[0034] In one specific embodiment, during the startup phase, the peak value of the instantaneous current is captured in real time through the high-frequency sampling mechanism of the electricity metering chip, and the dynamic protection threshold is adjusted accordingly. The filtering time is set relatively short at this stage, typically on the order of one to several milliseconds, to quickly identify abnormal states during startup. For example, when the motor starts, the effective current rises rapidly and may exceed the dynamic protection threshold. At this time, the MCU starts a timer to monitor whether the current continues to exceed the threshold. If the duration exceeds the defined filtering time, a fault is determined to have occurred in the startup process, such as a short circuit or motor jamming; if the duration does not reach the filtering time, the MCU considers this current change to be part of the startup characteristics rather than an anomaly and does not trigger protection action. This time-based logic avoids erroneous operations and provides the necessary tolerance for the motor to complete startup.

[0035] The implementation logic differs slightly during the operation phase. Since current fluctuations are typically less severe than during startup, the filtering time is set relatively long in this phase to better adapt to load changes during operation. This phase utilizes the low-frequency sampling mechanism of the power metering chip, with the MCU analyzing the effective current trend in real time. If the operating current continuously exceeds the protection threshold and the duration exceeds the preset filtering time (e.g., more than 50 milliseconds), the system will determine that an overload or other abnormality exists. If the motor enters an overload state, it may cause abnormal increases in winding temperature, or even damage the motor itself. In this case, once the filtering time is reached, the MCU control unit will respond quickly, disconnecting the power supply path by turning off the main thyristor to protect the motor.

[0036] In one embodiment, such as Figure 3 As shown, the setting of the current dynamic protection threshold includes: During the motor start-up phase, S21, obtaining a series of start-up phase effective current values ​​and a series of start-up phase effective voltage values ​​by high-frequency sampling of effective current and effective voltage values ​​using an electrical metering chip; S22, identifying a peak start-up current value from the series of start-up phase effective current values; S23, calculating a start-up voltage value based on the timestamp of the peak start-up current value and the series of start-up phase effective voltage values; S24, calculating a reference overcurrent protection threshold based on the peak start-up current value and the start-up voltage value. During the motor stable operation phase, S25, obtaining the operation phase effective current and operation phase effective voltage values ​​by low-frequency sampling of effective current and effective voltage values ​​using an electrical metering chip; S26, calculating a dynamic adjustment coefficient based on the operation phase effective current and operation phase effective voltage values; S27, dynamically adjusting the reference overcurrent protection threshold based on the dynamic adjustment coefficient to obtain the current dynamic protection threshold.

[0037] During the motor startup phase, the electrical metering chip continuously collects effective current and voltage values ​​through a high-frequency sampling mechanism (typically several kilohertz, such as 5kHz or 10kHz), generating a series of startup data sets. These data sets constitute a complete record of the electrical characteristics during startup and are the basis for identifying the peak starting current value. The peak of the effective current often occurs when the motor just begins to overcome the stationary torque, at which point the current rises rapidly and forms a significant peak fluctuation. The MCU control unit monitors this trend in real time and, using the continuously sampled current curve, compares data from adjacent time points to find the maximum value of the starting current, thereby accurately confirming the peak starting current value and its corresponding timestamp.

[0038] Once the timestamp of the peak startup current value is determined, the process of calculating the startup voltage value will then commence. In one embodiment, such as... Figure 4As shown, the starting voltage value is calculated based on the timestamp of the peak starting current value and the series of effective voltage values ​​during the starting phase, including: S231, based on the timestamp of the peak starting current value, a short-time window near the peak of the effective voltage value is extracted from the series of effective voltage values ​​during the starting phase, wherein the timestamp of the peak starting current value is located at the center of the short-time window near the peak of the effective voltage value; S232, the average of all effective voltage values ​​during the starting phase in the short-time window near the peak of the effective voltage value is calculated as the starting voltage value.

[0039] In one embodiment, calculating a reference overcurrent protection threshold based on the peak starting current value and the starting voltage value includes: calculating the reference overcurrent protection threshold based on the peak starting current value and the starting voltage value using the following formula, wherein the formula is: ;in, Peak starting current value, For the start-up voltage value, The multiple between the preset peak starting current value and the rated operating current value. To preset the overload factor, This represents the reference overcurrent protection threshold. The multiple between the preset peak starting current and the rated operating current reflects the difference in current characteristics between the motor's starting process and stable operation. The preset overload coefficient indicates the ratio of the system's maximum allowable current to the rated current; it directly determines the sensitivity of the protection threshold to dynamic changes and can be obtained based on the motor type or specific load characteristics. Of course, this is just an example and can be adjusted according to the actual situation. This application does not impose any specific limitations.

[0040] here, As a multiple between the preset peak starting current value and the rated operating current value, and The preset overload factor reflects the ratio between the maximum allowable current and the rated operating current. and Clearly, there is a definite correlation. However, due to the need to consider the differences between the starting and stable operation phases of a single-phase asynchronous motor, it is not suitable to directly determine the starting phase involved here using commonly used operating phase values. and In other words, during the startup phase, it is necessary to... and The dynamic balance between them is adjusted to avoid distortion of the overload coefficient preset due to instantaneous processes.

[0041] Based on this, in another embodiment, the startup phase is determined. and This includes: first obtaining the general operational phase values. and The method can be obtained based on the motor type or specific load characteristics as described in the previous embodiment, for example... Then based on reciprocal and The probabilistic coupling relationship between them is calculated by determining the first dynamic equilibrium quantization modeling coefficient and the second dynamic equilibrium quantization modeling coefficient, which are expressed as follows: ;in Adjusting parameters for dynamic correlation balance, This represents the first dynamic equilibrium quantization modeling coefficient. This represents the second dynamic balance quantization modeling coefficient. In other words, the higher the multiple between the peak starting current value and the rated operating current value, the lower the preset overload coefficient should be set to achieve dynamic protection.

[0042] However, a smooth adjustment based on correlation mutations is also needed. This can be achieved by introducing the natural logarithm function, that is, based on the first dynamic equilibrium quantization modeling coefficients and the second dynamic equilibrium quantization modeling coefficients, for... A smoothing adjustment based on correlational mutations is performed to obtain a smoothing adjustment factor, denoted as: ;in, This is a mutation regulation parameter used to characterize tolerance to relevant mutations. Indicates the smoothing adjustment factor. This represents the natural logarithm function.

[0043] Thus, based on the first dynamic balance quantization modeling coefficient, the second dynamic balance quantization modeling coefficient, and the smoothing adjustment factor, it is possible to... and Perform corrections to obtain the startup phase. and to carry out and The dynamic balance between them is adjusted, that is: Therefore, during the correction process, while performing smoothing adjustments based on the natural logarithm function, the square root operation is used to enhance sensitivity to low-correlation values, thus suppressing nonlinear false correlation characteristics. and There exists a dynamic balance relationship of probabilistic coupling and coordination, which improves its numerical accuracy and thus improves the reference overcurrent protection during the motor startup phase.

[0044] Next, considering the complex and diverse load changes of single-phase asynchronous motors in actual operation, which exceed the sensitivity range of traditional fixed threshold protection mechanisms, during the stable operation phase of the motor, effective current and voltage values ​​are sampled at low frequencies (e.g., 50Hz to 200Hz) by an electrical metering chip to obtain the effective current and voltage values ​​for the operating phase. Based on these effective current and voltage values, a dynamic adjustment coefficient is calculated, and the reference overcurrent protection threshold is dynamically adjusted based on this coefficient to obtain the dynamic current protection threshold. The purpose of dynamically adjusting the reference overcurrent protection threshold based on the dynamic adjustment coefficient is to consider the protection requirements of the motor under different load levels, ensuring that the motor remains in a safe protection state without causing false triggering or hardware damage due to overly stringent protection. The dynamic adjustment mechanism adjusts the protection strategy to reflect the current load state, achieving a balance between performance and protection. In particular, the introduction of the dynamic adjustment coefficient effectively adapts to the significant difference between the high current fluctuations during startup and the stable current during stable operation, making the system more flexible.

[0045] In one embodiment, such as Figure 5 As shown, the dynamic adjustment coefficient is calculated based on the effective current value and the effective voltage value of the operating phase, including: S261, calculating the current active power value based on the effective current value and the effective voltage value of the operating phase, wherein the current active power value is the effective current value of the operating phase multiplied by the effective voltage value of the operating phase and then multiplied by the power factor; S262, the MCU control unit obtains the rated active power value; S263, calculating the normalized load factor based on the current active power value and the rated active power value, wherein the normalized load factor is the current active power value divided by the rated active power value; S264, determining the load dispersion level label based on the normalized load factor; S265, matching the dynamic adjustment coefficient from the dynamic adjustment coefficient table based on the load dispersion level label.

[0046] In one specific embodiment, the effective current during operation is 10A, the effective voltage during operation is 220V, and the power factor is 0.85. Therefore, the current active power is calculated as 10 × 220 × 0.85 = 1870W. Simultaneously, the preset rated active power is 2000W, so the normalized load factor is calculated as 1870 ÷ 2000 = 0.935. This value is close to the rated load range, indicating that the motor is currently operating under a relatively normal workload. Then, based on this normalized load factor, a corresponding dynamic adjustment coefficient can be matched. In one embodiment, the load discrete level labels include no-load, very light load, medium load, rated load, and instantaneous overload. The label corresponding to the normalized load factor of 0.935 is rated load, and the matched dynamic adjustment coefficient is 0.9. Finally, based on the calculated dynamic adjustment coefficient, the reference overcurrent protection threshold is dynamically adjusted to obtain the current dynamic protection threshold. Specifically, the current dynamic protection threshold can be obtained by multiplying the dynamic adjustment coefficient and the reference overcurrent protection threshold. Simultaneously, when the real-time effective current value exceeds the dynamic protection threshold and the duration exceeds the preset filtering time, the protection action is triggered, and abnormal data recording is started synchronously. The system stores all parameters related to the abnormality in the internal storage module, including peak current, peak voltage, timestamp of the abnormality, and dynamic adjustment coefficient.

[0047] In summary, the single-phase asynchronous motor starting control circuit with anomaly detection provided in this application includes an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit. The main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit. The MCU control unit executes control logic, precisely controlling the on / off timing of the main and secondary thyristors to optimize the motor starting process and reduce starting shock. It also judges abnormal states based on real-time current and voltage data provided by the electrical metering chip and quickly takes protective measures when an anomaly is detected. Furthermore, it records key operating parameters when an abnormal state occurs, providing a basis for subsequent fault analysis, greatly simplifying the fault diagnosis process and reducing maintenance costs.

[0048] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0049] The flowcharts of the methods involved in this application are merely illustrative examples and are not intended to require or imply that connections, arrangements, or configurations must be made in the manner shown in the flowcharts. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0050] It should also be noted that the steps in the method of this application can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of this application.

[0051] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this 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 this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0052] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A single-phase asynchronous motor starting control circuit with anomaly detection, characterized in that, The single-phase asynchronous motor starting control circuit includes an MCU control unit, a main thyristor, a secondary thyristor, an electrical metering chip, and a protection circuit; the main thyristor, the secondary thyristor, the electrical metering chip, and the protection circuit are directly or indirectly electrically connected to the MCU control unit. The MCU control unit is used to execute control logic, which includes controlling the turn-on and turn-off timing of the main thyristor and the auxiliary thyristor, judging abnormal states based on real-time data from the electricity metering chip, executing protection actions, and recording key operating parameters when abnormal states occur. The abnormal state judgment based on real-time data from the electricity metering chip includes: receiving the real-time effective current value collected by the electricity metering chip; comparing the real-time effective current value with the current dynamic protection threshold to determine whether a first condition is met; and when it is determined that the first condition is met, the MCU control unit turns off the main thyristor. The setting of the current dynamic protection threshold includes: During the motor startup phase, a series of startup phase effective current values ​​and a series of startup phase effective voltage values ​​are obtained by high-frequency sampling of effective current values ​​and effective voltage values ​​by an electrical metering chip; a peak startup current value is identified from the series of startup phase effective current values; a startup voltage value is calculated based on the timestamp of the peak startup current value and the series of startup phase effective voltage values; and a reference overcurrent protection threshold is calculated based on the peak startup current value and the startup voltage value. During the stable operation phase of the motor, the effective current value and effective voltage value are sampled at low frequency by the electricity metering chip to obtain the effective current value and effective voltage value during the operation phase; based on the effective current value and effective voltage value during the operation phase, a dynamic adjustment coefficient is calculated; based on the dynamic adjustment coefficient, the reference overcurrent protection threshold is dynamically adjusted to obtain the current dynamic protection threshold.

2. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 1, characterized in that, The first condition is that the effective current value exceeds the current dynamic protection threshold and the duration exceeds the preset filtering time.

3. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 1, characterized in that, Based on the timestamp of the peak starting current value and the series of effective voltage values ​​during the starting phase, the starting voltage value is calculated, including: Based on the timestamp of the peak starting current value, a short-time window near the peak of the effective voltage value is extracted from the effective voltage values ​​of the series of starting stages, wherein the timestamp of the peak starting current value is located at the center of the short-time window near the peak of the effective voltage value; The average of all effective voltage values ​​during the startup phase within a short-time window near the peak value of the effective voltage value is calculated as the startup voltage value.

4. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 1, characterized in that, Based on the peak starting current value and the starting voltage value, a reference overcurrent protection threshold is calculated, including: based on the peak starting current value and the starting voltage value, the reference overcurrent protection threshold is calculated using the following formula, wherein the formula is: ;in, Peak starting current value, For the start-up voltage value, The multiple between the preset peak starting current value and the rated operating current value. To preset the overload factor, This indicates the reference overcurrent protection threshold.

5. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 4, characterized in that, Determine the start-up phase and ,include: Obtain general runtime phase values and ; based on reciprocal and The probabilistic coupling relationship between them is used to calculate the first dynamic equilibrium quantization modeling coefficient and the second dynamic equilibrium quantization modeling coefficient. Based on the first dynamic equilibrium quantization modeling coefficient and the second dynamic equilibrium quantization modeling coefficient, A smoothing adjustment based on correlational mutations is performed to obtain a smoothing adjustment factor; Based on the first dynamic equilibrium quantization modeling coefficient, the second dynamic equilibrium quantization modeling coefficient, and the smoothing adjustment factor, and Perform corrections to obtain the startup phase. and .

6. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 1, characterized in that, Based on the effective current value and the effective voltage value during the operating phase, the dynamic adjustment coefficient is calculated, including: Based on the effective current value and the effective voltage value of the operating phase, the current active power value is calculated. The current active power value is the effective current value of the operating phase multiplied by the effective voltage value of the operating phase and then multiplied by the power factor. The MCU control unit obtains the rated active power value; Based on the current active power value and the rated active power value, a normalized load factor is calculated, wherein the normalized load factor is the current active power value divided by the rated active power value. Based on the normalized load factor, determine the load dispersion level label; The dynamic adjustment coefficients are matched from the dynamic adjustment coefficient table based on the load discrete level label.

7. The single-phase asynchronous motor starting control circuit with anomaly detection according to claim 6, characterized in that, The load discrete level labels include no load, very light load, medium load, rated load, and instantaneous overload.

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