High-speed permanent magnet motor control system of air compressor

Abstract

The invention discloses a high-speed permanent magnet motor control system of an air compressor, and belongs to the technical field of motor control, the high-speed permanent magnet motor control system comprises an input power supply and a motor, and the input power supply supplies power to the motor; the adjusting module is electrically connected between the input power supply and the motor, and the adjusting module is used for adjusting the input voltage and current of the motor; and the acquisition module is electrically connected with the adjusting module. Through fusing information of the two modules, the fusion module can utilize respective advantages to improve the accuracy of rotation speed and position estimation, thereby providing a more reliable information basis for a PID control algorithm, and improving the precision and stability of motor control. The fusion module can cope with the change of the working state of the motor and the environmental condition, and adapt to different working conditions by dynamically adjusting the weight coefficient, so that the motor control system can still keep good performance in a complex and changeable environment.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and more specifically, to a high-speed permanent magnet motor control system for an air compressor. Background Art

[0002] Air compressors are indispensable equipment in industrial production. They are used to provide compressed air to meet the air source needs of various equipment and tools. Traditional air compressors are often driven by induction motors. As the driving motor of the compressor, the induction motor has the outstanding advantages of simple structure and does not contain permanent magnets. However, it also has disadvantages. The position sensor is mostly installed at the end of the motor. Therefore, when designing the motor, it is necessary to consider the space required for the position sensor. In some special occasions, the space is relatively small, and the size of the motor increases due to the installation of the position sensor. When the position sensor is installed at the end of the motor, if it is not installed in a reasonable position, the jitter of the motor shaft will increase, affecting the control accuracy. At the same time, after the position sensor is installed, the active loss and rotational inertia of the motor will also increase, causing unnecessary consumption.

[0003] In the field of air compressors, sensorless control motor systems can avoid the use of position sensors, reduce system costs, and improve system adaptability and reliability. However, most existing sensorless control motor systems use a single control system to control the motor. This design is often limited in its control performance and stability when faced with complex and changeable working conditions and load changes. Since a single control system is usually based on a fixed mathematical model or control algorithm, its control accuracy may be affected when the working conditions or loads change. Especially in nonlinear, time-varying or high-uncertainty systems, the control accuracy of a single control system is often difficult to guarantee. Summary of the invention

[0005] To solve the above problems, the present invention adopts the following technical solutions.

[0006] A high-speed permanent magnet motor control system for an air compressor comprises an input power supply and a motor, wherein the input power supply supplies power to the motor;

[0007] A regulating module, the regulating module is electrically connected between the input power supply and the motor, and the regulating module is used to regulate the input voltage and current to the motor;

[0008] A collection module, the collection module is electrically connected to the adjustment module, the collection module includes a current collection module and a voltage collection module, the current collection module is used to collect the input current of the motor, and the voltage collection module is used to collect the input voltage of the motor;

[0009] A processing unit, the processing unit is electrically connected to the acquisition module, the processing unit is electrically connected to the adjustment module, the processing unit also includes a first processing module, a second processing module and a fusion module, the first processing module and the second processing module are used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, the fusion module compares and fuses the rotation speed and position relationship of the shaft in the first processing module with the rotation speed and position relationship of the shaft in the second processing module, generates current and voltage control signals and inputs them into the adjustment module;

[0010] A protection module, wherein the protection module is electrically connected between the regulating module and the motor, and comprises an overcurrent protection module, an overvoltage protection module and an overheating protection module. The overcurrent protection module is used to detect the input current and output current in the regulating module, the overvoltage protection module is used to detect the input voltage and output voltage in the regulating module, and the overheating protection module is used to detect the temperature of the components in the regulating module.

[0011] Furthermore, the current acquisition module is used to acquire the input current of the motor, and the voltage acquisition module is used to acquire the input voltage of the motor, including:

[0012] When the motor is working, current flows through the circuit. The current sensor in the current acquisition module senses the magnetic field generated by the current using the electromagnetic induction principle or the Hall effect technology. The current sensor converts the sensed magnetic field signal into an electrical signal, amplifies and filters the electrical signal, and converts the processed signal into a digital signal through analog-to-digital conversion and inputs it into the processing unit.

[0013] The voltage acquisition module uses a voltage divider circuit to reduce the input voltage. The voltage divider circuit is composed of resistors. By selecting appropriate resistance values, the high voltage is reduced to a measurable range according to a certain ratio. The voltage signal after voltage division is processed by the signal conditioning circuit, including amplification and filtering. The conditioned voltage signal is converted into a digital signal through analog-to-digital conversion and input into the processing unit.

[0014] The digital current signal and the digital voltage signal are stored in real time, and the storage time is recorded for subsequent analysis and diagnosis.

[0015] Furthermore, the first processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including:

[0016] The first processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and calculates the back electromotive force of the motor according to I(t) and V(t). The specific calculation formula is:

[0017] Where Eb (t) is the back EMF, L is the inductance of the motor winding;

[0018] The first processing module calculates the rotation speed of the shaft using the linear relationship between the back electromotive force and the shaft angular velocity ω1(t). The specific calculation formula is:

[0019] Where Ke is the back EMF constant (related to the motor design), R is the resistance of the motor winding, λ(t) is the flux linkage of the motor, and ΔV los (t) is the voltage disturbance caused by external load changes;

[0020] The position of the rotating shaft is calculated according to the rotating shaft angular velocity ω1(t). The first processing module integrates the rotating shaft speed. Assuming the initial position of the rotor is θ0, the position of the rotating shaft θ1(t) can be expressed as:

[0021] where ν(τ) is the correction term used to compensate for the accumulated error in the integration process, and ∈log(t) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

[0022] Furthermore, the second processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including:

[0023] The second processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and inputs I(t) and V(t) into the neural network model. The neural network model learns the relationship between the current, voltage and the rotation speed and position of the shaft in a large amount of historical data in advance to form a nonlinear mapping. The angular velocity of the shaft in the second processing module is expressed as ω2(t), and the position of the shaft is expressed as θ2(t), where

[0024] The calculation of ω2(t) is:

[0025]

[0026] Where fea(I(t),V(t)) is the feature extracted from the current and voltage signals, which are based on machine learning features; θ mod are the parameters of the model, which are determined by training data; his(ω) is the historical information of the speed, which is used to capture the dynamic characteristics of the motor, such as acceleration, deceleration, etc.; ΔV dis (t) is the voltage disturbance caused by external interference, ε senr (t) is the current and voltage measurement error caused by noise in the detection module, dyna(ω,θ) is the dynamic equation of the motor, which is used to describe the relationship between the speed and position over time;

[0027] θ2(t) is calculated as:

[0028] Where θ0 is the initial position of the axis of rotation, is the integral of the speed, used to calculate the position, εint(t) is the cumulative error introduced during the integration process, mec lag (ω,θ) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

[0030] Furthermore, the fusion module compares and fuses the rotation speed and position relationship of the rotating shaft in the first processing module with the rotation speed and position relationship of the rotating shaft in the second processing module, generates current and voltage control signals and inputs them into the regulation module, including:

[0031] The fusion module performs a detailed comparative analysis on the speed and position information provided by the first processing module and the second processing module, calculates the degree of difference between the information from different sources, quantifies the difference by calculating the speed difference and position deviation, and analyzes the similarities. The specific fusion method of ω1(t) and ω2(t), θ1(t) and θ2(t) is as follows:

[0032] ω mix (t) = αω1(t) + (1-α)ω2(t), where α is the weight coefficient, 0≤α≤1;

[0033] θ mix (t) = βθ1(t) + (1-β)θ2(t), where β is the weight coefficient, 0≤β≤1; α and β can be dynamically adjusted according to the working state and environmental conditions of the motor, including the motor's load, temperature, vibration, speed stability, etc.;

[0034] The obtained ω mix (t) and θ mix (t) According to the PID control algorithm, the output current Ic used to control the motor ontrol and voltage U control .

[0035] Furthermore, the overcurrent protection module is used to detect the input current and output current in the regulation module, including:

[0036] The overcurrent protection module monitors the input current and output current in the regulation module in real time. If the current exceeds the preset safety threshold, the input current in the regulation module is cut off. The overcurrent protection module adopts current transformer and comparator circuit. If the input current and output current detected by the current transformer exceed the preset safety threshold, the comparator outputs a high-level signal to trigger the protection logic circuit. The protection logic circuit cuts off the drive signal of the power switching device and sends an alarm signal.

[0037] Furthermore, the overvoltage protection module is used to detect the input voltage and output voltage in the regulation module, including:

[0038] The overvoltage protection module consists of a voltage monitoring circuit and a protection relay. The voltage monitoring circuit consists of a voltage sensor and a comparator circuit. If the voltage detected by the voltage sensor exceeds the preset safety threshold, the comparator outputs a high-level signal to trigger the protection relay. The protection relay responds to the electromagnetic relay or solid-state relay to cut off the power input.

[0039] Furthermore, the overheat protection module is used to detect the temperature of the components in the regulating module, including:

[0040] The overheat protection module uses a thermistor or temperature sensor to monitor the component temperature in real time. If the temperature reaches the warning value, the protection module will send an alarm signal to remind the user to take corresponding measures; if the temperature rises to a dangerous value, the input circuit in the regulation module will be automatically cut off.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This solution fuses the information of the two modules. The fusion module can utilize the advantages of each module to improve the accuracy of speed and position estimation, which provides a more reliable information basis for the PID control algorithm, thereby improving the accuracy and stability of motor control; the fusion module can cope with changes in the motor's working state and environmental conditions, and adapt to different working conditions by dynamically adjusting the weight coefficient, which enables the motor control system to maintain good performance in a complex and changing environment and enhances the robustness of the system; through comparative analysis, the fusion module can identify which module's information is more reliable or accurate, and adjust the weight coefficient accordingly, which helps to optimize resource utilization and avoid over-reliance on a potentially unreliable module. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 It is a schematic diagram of a control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0046] like Figure 1 As shown, a high-speed permanent magnet motor control system for an air compressor comprises:

[0047] An input power source and a motor, wherein the input power source supplies power to the motor;

[0048] A regulating module, the regulating module is electrically connected between the input power supply and the motor, and the regulating module is used to regulate the input voltage and current to the motor;

[0049] A collection module, the collection module is electrically connected to the adjustment module, the collection module includes a current collection module and a voltage collection module, the current collection module is used to collect the input current of the motor, and the voltage collection module is used to collect the input voltage of the motor;

[0050] A processing unit, the processing unit is electrically connected to the acquisition module, the processing unit is electrically connected to the adjustment module, the processing unit also includes a first processing module, a second processing module and a fusion module, the first processing module and the second processing module are used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, the fusion module compares and fuses the rotation speed and position relationship of the shaft in the first processing module with the rotation speed and position relationship of the shaft in the second processing module, generates current and voltage control signals and inputs them into the adjustment module;

[0051] A protection module, wherein the protection module is electrically connected between the regulating module and the motor, and comprises an overcurrent protection module, an overvoltage protection module and an overheating protection module. The overcurrent protection module is used to detect the input current and output current in the regulating module, the overvoltage protection module is used to detect the input voltage and output voltage in the regulating module, and the overheating protection module is used to detect the temperature of the components in the regulating module.

[0052] In a preferred embodiment of the present invention, the current acquisition module is used to acquire the input current of the motor, and the voltage acquisition module is used to acquire the input voltage of the motor, including:

[0053] When the motor is working, current flows through the circuit. The current sensor in the current acquisition module senses the magnetic field generated by the current using the electromagnetic induction principle or the Hall effect technology. The current sensor converts the sensed magnetic field signal into an electrical signal, amplifies and filters the electrical signal, and converts the processed signal into a digital signal through analog-to-digital conversion and inputs it into the processing unit.

[0054] The voltage acquisition module uses a voltage divider circuit to reduce the input voltage. The voltage divider circuit is composed of resistors. By selecting appropriate resistance values, the high voltage is reduced to a measurable range according to a certain ratio. The voltage signal after voltage division is processed by the signal conditioning circuit, including amplification and filtering. The conditioned voltage signal is converted into a digital signal through analog-to-digital conversion and input into the processing unit.

[0055] The digital current signal and the digital voltage signal are stored in real time, and the storage time is recorded for subsequent analysis and diagnosis.

[0056] By adopting the above technical solution, when current passes through the circuit, a magnetic field is generated. The current sensor in the current acquisition module uses the electromagnetic induction principle or the Hall effect technology to sense the magnetic field generated by the current. The electromagnetic induction principle is that when the magnetic field changes, an electromotive force will be generated in the conductor. The current sensor indirectly measures the current by sensing this electromotive force. The Hall effect technology uses the phenomenon that the Hall element generates a potential difference when it is deflected in the magnetic field. The current is measured by measuring this potential difference. The current sensor converts the sensed magnetic field signal into an electrical signal. Since the initial electrical signal may be weak, it needs to be amplified by an amplifier circuit for subsequent processing. The amplified electrical signal may contain high-frequency noise or interference, so it needs to be filtered by a filter to remove these unnecessary components. The analog signal after filtering is converted into a digital signal by an analog-to-digital converter (ADC). The digital signal has higher anti-interference ability and is more convenient for subsequent processing and analysis. The digital current signal is stored in real time and the storage time is recorded. These data can be used for subsequent analysis and diagnosis to monitor the operating status and performance of the motor.

[0057] The voltage acquisition module uses a voltage divider circuit to reduce the input voltage. The voltage divider circuit is composed of resistors. By selecting the appropriate resistance value, the high voltage is reduced to a measurable range at a certain ratio. The voltage signal after voltage division may still require further conditioning, including amplification and filtering. The amplification circuit is used to increase the amplitude of the signal for subsequent processing; the filter is used to remove high-frequency noise or interference in the signal. The conditioned voltage signal is also converted into a digital signal through an analog-to-digital converter (ADC). The digital voltage signal is stored in real time and the storage time is recorded. These data can also be used for subsequent analysis and diagnosis to monitor the voltage changes and power supply stability of the motor.

[0058] In a preferred embodiment of the present invention, the first processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including:

[0059] The first processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and calculates the back electromotive force of the motor according to I(t) and V(t). The specific calculation formula is:

[0060] Where E b (t) is the back EMF, L is the inductance of the motor winding;

[0061] The first processing module calculates the rotation speed of the shaft using the linear relationship between the back electromotive force and the shaft angular velocity ω1(t). The specific calculation formula is:

[0062] Where Ke is the back EMF constant (related to the motor design), R is the resistance of the motor winding, λ(t) is the flux linkage of the motor, and ΔV los (t) is the voltage disturbance caused by external load changes;

[0063] The position of the rotating shaft is calculated according to the rotating shaft angular velocity ω1(t). The first processing module integrates the rotating shaft speed. Assuming the initial position of the rotor is θ0, the position of the rotating shaft θ1(t) can be expressed as:

[0064] θ1(t)=θ0+∫0 t (ω(t)+ν(τ))dτ-∈log(t), where ν(τ) is the correction term used to compensate for the accumulated error in the integration process, and ∈log(t) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

[0065] By adopting the above technical solution, the back electromotive force and the rotational speed are accurately calculated, and the first processing module can realize accurate estimation of the motor shaft position and rotational speed. The first processing module can cope with interference factors such as external load changes and mechanical lag, and reduce the impact of these interferences on position estimation by introducing correction terms and accurate calculation methods.

[0066] In a preferred embodiment of the present invention, the second processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including:

[0067] The second processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and inputs I(t) and V(t) into the neural network model. The neural network model learns the relationship between the current, voltage and the rotation speed and position of the shaft in a large amount of historical data in advance to form a nonlinear mapping. The angular velocity of the shaft in the second processing module is expressed as ω2(t), and the position of the shaft is expressed as θ2(t), where

[0068] The calculation of ω2(t) is:

[0069]

[0070] Where fea(I(t),V(t)) is the feature extracted from the current and voltage signals, which are based on machine learning features; θ mod are the parameters of the model, which are determined by training data; his(ω) is the historical information of the speed, which is used to capture the dynamic characteristics of the motor, such as acceleration, deceleration, etc.; ΔV dis (t) is the voltage disturbance caused by external interference, ε senr (t) is the current and voltage measurement error caused by noise in the detection module, dyna(ω,θ) is the dynamic equation of the motor, which is used to describe the relationship between the speed and position over time;

[0071] θ2(t) is calculated as:

[0072] Where θ0 is the initial position of the axis of rotation, is the integral of the speed, used to calculate the position, εint(t) is the cumulative error introduced during the integration process, mec lag (ω,θ) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

[0074] By adopting the above technical solution, the second processing module first receives the digital current signal and digital voltage signal from the current acquisition module and the voltage acquisition module. Then, the module uses a machine learning algorithm to extract key features from the current and voltage signals. These features can reflect the operating status and dynamic characteristics of the motor. The extracted features are input into a pre-trained neural network model. The neural network model can be any one of a feedforward neural network, a convolutional neural network, a recurrent neural network, a fuzzy neural network and a BP neural network. This model is based on a large amount of historical data and learns the complex nonlinear relationship between current, voltage and shaft speed and position. The neural network model maps the input features to the shaft speed and position output through its internal structure and parameters. In the output of the neural network model, The angular velocity of the shaft is calculated based on factors such as input characteristics, model parameters, historical speed information, and external interference. The historical speed information is used to capture the dynamic characteristics of the motor, such as acceleration and deceleration, which helps to predict the current speed more accurately. The position of the shaft is calculated by integrating the speed. The initial position is known, and the integration process accumulates the speed information to obtain real-time position information. In order to compensate for the errors that may accumulate during the integration process, a correction term is introduced. This correction term can be adjusted according to actual conditions to reduce the position estimation error caused by mechanical lag (such as bearing friction, etc.). During the calculation process, the dynamic equation of the motor is also considered, which describes the relationship between the speed and position over time, which helps to further improve the accuracy and stability of the estimation.

[0075] In a preferred embodiment of the present invention, the fusion module compares and fuses the rotation speed and position relationship of the rotating shaft in the first processing module with the rotation speed and position relationship of the rotating shaft in the second processing module, generates current and voltage control signals and inputs them into the regulation module, including:

[0076] The fusion module performs a detailed comparative analysis on the speed and position information provided by the first processing module and the second processing module, calculates the degree of difference between the information from different sources, quantifies the difference by calculating the speed difference and position deviation, and analyzes the similarities. The specific fusion method of ω1(t) and ω2(t), θ1(t) and θ2(t) is as follows:

[0077] ω mix (t) = αω1(t) + (1-α)ω2(t), where α is the weight coefficient, 0≤α≤1;

[0078] θ mix (t) = βθ1(t) + (1-β)θ2(t), where β is the weight coefficient, 0≤β≤1; α and β can be dynamically adjusted according to the working state and environmental conditions of the motor, including the motor's load, temperature, vibration, speed stability, etc.;

[0079] The obtained ω mix (t) and θ mix (t) According to the PID control algorithm, the output current I is used to control the motor control and voltage U control .

[0080] By adopting the above technical solution, the fusion module first receives the speed and position information from the first processing module and the second processing module. The fusion module calculates the difference between the speed and position information provided by the two modules, which is usually achieved by calculating the speed difference (|ω1(t)-ω2(t)|) and the position deviation (|θ1(t)-θ2(t)|). These differences are analyzed to determine whether they are within an acceptable range and to identify which information is more reliable or accurate. According to the results of the comparative analysis, the fusion module uses a weighted average method to fuse the speed and position information of the two modules. The weight coefficient is dynamically adjusted according to the working state and environmental conditions of the motor. These factors include the motor's load, temperature, vibration, speed stability, etc. Finally, the fused speed and position are obtained. The fusion module uses the obtained fused speed and position information as the input of the PID control algorithm. The PID control algorithm calculates the current and voltage signals used to control the motor based on the input information. These control signals are then input into the regulation module to achieve precise control of the motor. By fusing the information of the two modules, the fusion module can take advantage of their respective advantages to improve the accuracy of speed and position estimation, which provides a more reliable information basis for the PID control algorithm, thereby improving the accuracy and stability of motor control; the fusion module can cope with changes in the working state and environmental conditions of the motor, and adapt to different working conditions by dynamically adjusting the weight coefficient, which enables the motor control system to maintain good performance in a complex and changing environment and enhances the robustness of the system; through comparative analysis, the fusion module can identify which module's information is more reliable or accurate, and adjust the weight coefficient accordingly, which helps to optimize resource utilization and avoid over-reliance on a potentially unreliable module.

[0081] In a preferred embodiment of the present invention, the overcurrent protection module is used to detect the input current and the output current in the regulation module, including:

[0082] The overcurrent protection module monitors the input current and output current in the regulation module in real time. If the current exceeds the preset safety threshold, the input current in the regulation module is cut off. The overcurrent protection module adopts current transformer and comparator circuit. If the input current and output current detected by the current transformer exceed the preset safety threshold, the comparator outputs a high-level signal to trigger the protection logic circuit. The protection logic circuit cuts off the drive signal of the power switching device and sends an alarm signal.

[0083] By adopting the above technical solution, the overcurrent protection module uses a current transformer to monitor the input current and output current in the regulation module. The current transformer is a special transformer that can convert high current into low current (usually milliampere level) to facilitate measurement and protection of the circuit. In the overcurrent protection module, safety thresholds are preset. These thresholds are determined according to the rated current of the motor, working conditions and safety requirements of the system. When the monitored current exceeds these thresholds, the protection action will be triggered; the current signal detected by the current transformer is sent to the comparator circuit, and the comparator circuit compares the detected current signal with the preset safety threshold. If the detected current exceeds the threshold, the comparator outputs a high-level signal. When the comparator outputs a high-level signal, the signal is sent to the protection logic circuit, and the protection logic circuit immediately That is, the driving signal of the power switching device is cut off to disconnect the current path and prevent the current from continuing to rise. At the same time, the protection logic circuit also sends an alarm signal to notify the system administrator or maintenance personnel to pay attention and take corresponding measures. After cutting off the current, the overcurrent protection module usually provides a fault indication signal so that the system administrator can quickly locate and solve the problem. Once the fault is eliminated and the system is restored to a safe state, the overcurrent protection module can be reset manually or automatically to restore the normal operation of the system. The overcurrent protection module can monitor the current in real time and quickly cut off the current when it exceeds the safety threshold, effectively preventing equipment damage or safety accidents caused by excessive current. The fault indication signal provided by the overcurrent protection module helps the system administrator to quickly locate the problem, thereby speeding up troubleshooting and repair.

[0084] In a preferred embodiment of the present invention, the overvoltage protection module is used to detect the input voltage and output voltage in the regulation module, including:

[0085] The overvoltage protection module consists of a voltage monitoring circuit and a protection relay. The voltage monitoring circuit consists of a voltage sensor and a comparator circuit. If the voltage detected by the voltage sensor exceeds the preset safety threshold, the comparator outputs a high-level signal to trigger the protection relay. The protection relay responds to the electromagnetic relay or solid-state relay to cut off the power input.

[0086] By adopting the above technical solution, the voltage sensor is used as a front-end detection element to monitor the voltage level in the power system in real time. The sensor converts the high voltage signal into a low voltage signal for subsequent circuit processing. The converted voltage signal is sent to the comparator circuit. The comparator circuit has a preset safety threshold voltage, which is set according to the maximum safety voltage required by the system. When the signal output by the voltage sensor exceeds this threshold, the comparator circuit determines that the voltage is too high. Once the comparator detects that the voltage is abnormal (that is, it exceeds the safety threshold), it will immediately output a high-level signal. This signal is the key to triggering the subsequent protection action. The high-level signal is sent to the protection relay, which can be an electromagnetic relay or a solid-state relay. They control their contact state according to the type of signal received (here, an electrical signal). When a high-level signal is received, the relay contacts will change state, usually to the disconnected state, thereby cutting off the connection with the power input terminal. As the protection relay operates, the power originally supplied to the load is safely cut off, effectively preventing equipment damage or safety accidents that may be caused by excessive voltage; the overvoltage protection module can quickly respond to voltage abnormalities and cut off power in time, effectively avoiding equipment damage caused by excessive voltage and extending the service life of the equipment. By accurately monitoring the voltage and taking quick measures, the module helps maintain the stable operation of the power system and reduce system failures caused by voltage fluctuations. In the power system, overvoltage may cause safety hazards such as fire and electric shock. By adjusting the preset safety threshold, the overvoltage protection module can adapt to the voltage protection needs of different power systems, thereby improving its flexibility and breadth of application.

[0087] In a preferred embodiment of the present invention, the overheat protection module can be used to detect the temperature of the components in the regulating module, including:

[0088] The overheat protection module uses a thermistor or temperature sensor to monitor the component temperature in real time. If the temperature reaches the warning value, the protection module will send an alarm signal to remind the user to take corresponding measures; if the temperature rises to a dangerous value, the input circuit in the regulation module will be automatically cut off.

[0089] By adopting the above technical solution, the overheat protection module has a built-in thermistor or temperature sensor. These components are closely attached to or close to the components to be monitored, and sense their temperature changes in real time. The resistance of the thermistor changes with the temperature, and the temperature sensor directly outputs an electrical signal proportional to the temperature. The monitored temperature signal is converted into an electrical signal and sent to the signal processing circuit in the protection module. The circuit is provided with one or more preset temperature thresholds, including warning values ​​and danger values. The signal processing circuit compares the real-time monitored temperature signal with these thresholds. When the temperature reaches or exceeds the warning value, the protection module sends an alarm signal through the internal circuit or external interface, which can be in the form of flashing indicator lights, buzzer alarms, or sending digital signals to the control system, to remind users to pay attention and take corresponding measures, such as increasing heat dissipation, reducing loads, etc. If the temperature continues to rise and reaches or exceeds the danger value, the protection module will automatically trigger the cut-off mechanism, which usually involves controlling a relay or solid-state switch to disconnect the input circuit in the regulation module, thereby preventing components from being damaged due to overheating, or even causing serious consequences such as fire. The overheat protection module can monitor and respond to temperature anomalies in real time, take timely measures to prevent equipment damage due to overheating, and extend the service life and reliability of the equipment. By automatically cutting off the circuit, the overheat protection module significantly reduces the safety risks such as fire and electric shock caused by overheating of the equipment, and improves the safety of the working environment. The overheat protection module helps maintain the stable operation of the regulation module and its system, and reduces failures and downtime caused by temperature fluctuations. By issuing an alarm signal, the overheat protection module reminds users to pay attention to the status of the equipment, enhancing users' awareness of equipment maintenance and safety management.

[0090] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0091] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0092] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0093] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical disks.

[0094] In addition, it should be noted that in the apparatus and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. Moreover, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order, and some steps can be performed in parallel or independently of each other. For those of ordinary skill in the art, it is understood that all or any steps or components of the method and apparatus of the present invention can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in hardware, firmware, software or a combination thereof, which can be achieved by those of ordinary skill in the art using basic programming skills after reading the description of the present invention.

[0095] Therefore, the purpose of the present invention can also be achieved by running a program or a group of programs on any computing device. The computing device can be a well-known general device. Therefore, the purpose of the present invention can also be achieved by simply providing a program product containing a program code that implements the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be pointed out that in the device and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. In addition, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order. Some steps can be performed in parallel or independently of each other.

[0096] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-speed permanent magnet motor control system for an air compressor, characterized in that: include: An input power source and a motor, wherein the input power source supplies power to the motor; A regulating module, the regulating module is electrically connected between the input power supply and the motor, and the regulating module is used to regulate the input voltage and current to the motor; A collection module, the collection module is electrically connected to the adjustment module, the collection module includes a current collection module and a voltage collection module, the current collection module is used to collect the input current of the motor, and the voltage collection module is used to collect the input voltage of the motor; A processing unit, the processing unit is electrically connected to the acquisition module, the processing unit is electrically connected to the adjustment module, the processing unit also includes a first processing module, a second processing module and a fusion module, the first processing module and the second processing module are used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, the fusion module compares and fuses the rotation speed and position relationship of the shaft in the first processing module with the rotation speed and position relationship of the shaft in the second processing module, generates current and voltage control signals and inputs them into the adjustment module; A protection module, wherein the protection module is electrically connected between the regulating module and the motor, and comprises an overcurrent protection module, an overvoltage protection module and an overheating protection module. The overcurrent protection module is used to detect the input current and output current in the regulating module, the overvoltage protection module is used to detect the input voltage and output voltage in the regulating module, and the overheating protection module is used to detect the temperature of the components in the regulating module.

2. According to the high-speed permanent magnet motor control system of an air compressor according to claim, it is characterized in that: The current acquisition module is used to collect the input current of the motor, and the voltage acquisition module is used to collect the input voltage of the motor, including: When the motor is working, current flows through the circuit. The current sensor in the current acquisition module senses the magnetic field generated by the current using the electromagnetic induction principle or the Hall effect technology. The current sensor converts the sensed magnetic field signal into an electrical signal, amplifies and filters the electrical signal, and converts the processed signal into a digital signal through analog-to-digital conversion and inputs it into the processing unit. The voltage acquisition module uses a voltage divider circuit to reduce the input voltage. The voltage divider circuit is composed of resistors. By selecting appropriate resistance values, the high voltage is reduced to a measurable range according to a certain ratio. The voltage signal after voltage division is processed by the signal conditioning circuit, including amplification and filtering. The conditioned voltage signal is converted into a digital signal through analog-to-digital conversion and input into the processing unit. The digital current signal and the digital voltage signal are stored in real time, and the storage time is recorded for subsequent analysis and diagnosis.

3. According to the high-speed permanent magnet motor control system of an air compressor according to claim, it is characterized in that: The first processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including: The first processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and calculates the back electromotive force of the motor according to I(t) and V(t). The specific calculation formula is: Where E b (t) is the back EMF, L is the inductance of the motor winding; The first processing module calculates the rotation speed of the shaft using the linear relationship between the back electromotive force and the shaft angular velocity ω1(t). The specific calculation formula is: Where Ke is the back EMF constant (related to the motor design), R is the resistance of the motor winding, λ(t) is the flux linkage of the motor, and ΔV los (t) is the voltage disturbance caused by external load changes; The position of the rotating shaft is calculated according to the rotating shaft angular velocity ω1(t). The first processing module integrates the rotating shaft speed. Assuming the initial position of the rotor is θ0, the position of the rotating shaft θ1(t) can be expressed as: where ν(τ) is the correction term used to compensate for the accumulated error in the integration process, and ∈log(t) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

4. A high-speed permanent magnet motor control system for an air compressor according to claim 3, characterized in that: The second processing module is used to estimate the rotation speed and position relationship of the motor shaft according to the collected current signal and voltage signal, including: The second processing module receives the collected digital current signal I(t) and digital voltage signal V(t), and inputs I(t) and V(t) into the neural network model. The neural network model learns the relationship between the current, voltage and the rotation speed and position of the shaft in a large amount of historical data in advance to form a nonlinear mapping. The angular velocity of the shaft in the second processing module is expressed as ω2(t), and the position of the shaft is expressed as θ2(t), where The calculation of ω2(t) is: ω2(t)≈ f ω (I(t),V(t),fea(I(t),V(t),θ mod ,his(ω),ΔVB dis (t),ε senr (t),dyna(ω,θ)), where fea(I(t),V(t)) are the features extracted from the current and voltage signals, which are machine learning based features; θ mod are the parameters of the model, which are determined by training data; his(ω) is the historical information of the speed, which is used to capture the dynamic characteristics of the motor, such as acceleration, deceleration, etc.; ΔV dis (t) is the voltage disturbance caused by external interference, ε senr (t) is the current and voltage measurement error caused by noise in the detection module, dyna(ω,θ) is the dynamic equation of the motor, which is used to describe the relationship between the speed and position over time; θ2(t) is calculated as: Where θ0 is the initial position of the axis of rotation, is the integral of the speed, used to calculate the position, εint(t) is the cumulative error introduced during the integration process, mec lag (ω,θ) is the position estimation error caused by mechanical hysteresis (such as bearing friction, etc.).

5. A high-speed permanent magnet motor control system for an air compressor according to claim 4, characterized in that: The fusion module compares and fuses the speed and position relationship of the rotating shaft in the first processing module with the speed and position relationship of the rotating shaft in the second processing module, generates current and voltage control signals and inputs them into the regulation module, including: The fusion module performs a detailed comparative analysis on the speed and position information provided by the first processing module and the second processing module, calculates the degree of difference between the information from different sources, quantifies the difference by calculating the speed difference and position deviation, and analyzes the similarities. The specific fusion method of ω1(t) and ω2(t), θ1(t) and θ2(t) is: ω mix (t) = αω1(t) + (1-α)ω2(t), where α is the weight coefficient, 0≤α≤1; θ mix (t) = βθ1(t) + (1-β)θ2(t), where β is the weight coefficient, 0≤β≤1; α and β can be dynamically adjusted according to the working state and environmental conditions of the motor, including the motor's load, temperature, vibration, speed stability, etc.; The obtained ω mix (t) and θ mix (t) According to the PID control algorithm, the output current I is used to control the motor control and voltage U control .

6. A high-speed permanent magnet motor control system for an air compressor according to claim 5, characterized in that: The overcurrent protection module is used to detect the input current and output current in the regulation module, including: The overcurrent protection module monitors the input current and output current in the regulation module in real time. If the current exceeds the preset safety threshold, the input current in the regulation module is cut off. The overcurrent protection module adopts current transformer and comparator circuit. If the input current and output current detected by the current transformer exceed the preset safety threshold, the comparator outputs a high-level signal to trigger the protection logic circuit. The protection logic circuit cuts off the drive signal of the power switching device and sends an alarm signal.

7. A high-speed permanent magnet motor control system for an air compressor according to claim 6, characterized in that: The overvoltage protection module is used to detect the input voltage and output voltage in the regulation module, including: The overvoltage protection module consists of a voltage monitoring circuit and a protection relay. The voltage monitoring circuit consists of a voltage sensor and a comparator circuit. If the voltage detected by the voltage sensor exceeds the preset safety threshold, the comparator outputs a high-level signal to trigger the protection relay. The protection relay responds to the electromagnetic relay or solid-state relay to cut off the power input.

8. A high-speed permanent magnet motor control system for an air compressor according to claim 7, characterized in that: The overheat protection module is used to detect the temperature of components in the regulation module, including: The overheat protection module uses a thermistor or temperature sensor to monitor the component temperature in real time. If the temperature reaches the warning value, the protection module will send an alarm signal to remind the user to take corresponding measures; if the temperature rises to a dangerous value, the input circuit in the regulation module will be automatically cut off.

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