Frequency converter and frequency converter control system and method

Abstract

The invention discloses a frequency converter and a frequency converter control system and method, and relates to the technical field of frequency converter control, and the frequency converter control system comprises a data collection module which is used for collecting parameter information of the frequency converter and parameter information of a frequency converter load; the control module is used for adjusting the frequency output by the frequency converter according to the parameter information of the data acquisition module and the parameter information of the motor in the load fan of the frequency converter until the frequency of the frequency converter is matched with the set frequency of the motor in the load fan; the operation state of the frequency converter is monitored in real time through the data acquisition module, and the control module can adjust the output frequency of the frequency converter according to the information so as to meet the design requirement of the fan and ensure that the fan operates at the optimal working point; information provided by the data acquisition module can be quickly responded, and the output frequency of the frequency converter can be timely adjusted to adapt to load changes, such as changes of indoor temperature in an air conditioning system.

Description

Technical Field

[0001] The present invention relates to the technical field of frequency converter control, and more specifically, to a frequency converter and a frequency converter control system and method. Background Art

[0002] The control system of the inverter needs to consider many aspects, including hardware selection, control strategy, user interface, communication interface, protection mechanism, etc.

[0003] However, in actual use, the load of the inverter is not limited to a single motor, and it has a wide range of uses. For example, when the load of the inverter is a fan, the speed of the fan may need to run within a specific frequency range to maintain optimal efficiency. If the frequency setting range of the inverter does not match the design requirements of the fan, the fan may not be able to run at the optimal working point, resulting in reduced fan efficiency and increased energy consumption. Long-term operation may cause additional wear on the motor and fan.

[0004] Moreover, the fan may need to respond quickly to load changes in some applications. For example, in an air-conditioning system, when the indoor temperature changes, the fan speed needs to be adjusted quickly to maintain a constant temperature. If the dynamic response speed of the inverter is insufficient, the fan speed may not be adjusted in time, and the system may not be able to adapt to load changes quickly, resulting in a decrease in control accuracy, which may affect the overall system performance and user experience. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a frequency converter and a frequency converter control system and method.

[0006] In one aspect, the present invention provides a frequency converter control system, comprising a data acquisition module, wherein the data acquisition module is used to collect parameter information of the frequency converter and parameter information of the frequency converter load;

[0007] A control module, the control module is used to adjust the frequency output by the inverter according to the parameter information of the data acquisition module and the parameter information of the motor in the inverter load fan, until the frequency of the inverter matches the set frequency of the motor in the load fan;

[0008] A feedback module is used to monitor the operation of the inverter and the inverter load according to the information of the data acquisition module after the control module is adjusted, determine whether there is an abnormality, and formulate a feedback strategy according to the judgment result:

[0009] Preferably, the control module comprises the following steps:

[0010] Collect the real-time operation data of the inverter through the data acquisition module;

[0011] Obtain parameter information of the motor in the load fan;

[0012] The adjusted output frequency of the inverter is obtained through the real-time operation data of the inverter and the parameter information of the motor in the load fan;

[0013] The control module sends a command to the frequency converter, and adjusts the output frequency to match the load state according to the adjusted output frequency of the frequency converter;

[0014] After the adjustment is completed, the real-time operation data of the inverter continues to be collected through the data acquisition module, and the new status is fed back to the control module for analysis.

[0015] Preferably, obtaining the adjusted output frequency of the frequency converter comprises the following steps:

[0016] Obtain real-time data of the inverter, including the current, voltage and power factor of the motor in the load fan;

[0017] Obtain the torque requirement T of the motor in the inverter load fan;

[0018] Obtain the difference E between the actual speed of the motor in the inverter load fan and the set speed;

[0019] Obtain the difference Q between the torque demand T and the actual torque of the motor in the inverter load fan;

[0020] The output frequency adjustment value U of the inverter is obtained according to the speed difference E and the torque difference Q. The output frequency of the inverter is adjusted through the PID control algorithm to meet the torque demand and speed control. Specifically:

[0021] Integrate the speed difference to get ∫E(dt), and differentiate the speed difference to get

[0022] Integrating the torque difference gives ∫Q(dt), and differentiating the torque difference gives

[0023] According to the formula Calculate and obtain the adjusted output frequency H of the frequency converter;

[0024] in are the proportional, integral and differential gains of the speed, are the proportional, integral and differential gains of the torque;

[0025] The current frequency of the inverter is added to the output frequency adjustment value U to obtain the adjusted output frequency of the inverter;

[0026] The adjusted output frequency of the frequency converter is transmitted to the central processing unit to change the output frequency of the frequency converter.

[0027] Preferably, the specific working mode of the feedback module is as follows:

[0028] The fault diagnosis result is obtained according to the parameter information of the data acquisition module, and an early warning mechanism is set according to the fault diagnosis result. When an abnormal fault diagnosis result is detected, the system generates an early warning signal; after the early warning signal is generated, the diagnosis result is fed back to the control module, and the control module adjusts the control strategy according to the diagnosis result.

[0029] Preferably, the fault diagnosis result is obtained as follows:

[0030] Subtract the actual speed from the synchronous speed of the motor in the inverter load fan and divide it by the synchronous speed to obtain the motor slip F;

[0031] The fault detection rate G and the false alarm rate K of the frequency converter are obtained according to the slip F and the torque demand T of the motor, and the fault detection rate G and the false alarm rate K are marked as the fault diagnosis result.

[0032] Preferably, the control module adjusts the control strategy according to the diagnosis result in the following specific manner:

[0033] Based on the diagnosis results, determine whether it is necessary to adjust the output frequency adjustment value U or shut down for maintenance.

[0034] Preferably, the specific manner in which the control module adjusts the control strategy according to the diagnosis result also includes:

[0035] If the output frequency adjustment value U needs to be adjusted, the frequency adjustment value U is adjusted according to the diagnosis result;

[0036] If the diagnostic results indicate a slow response, increase the proportional gains of speed and torque to improve the response;

[0037] If the diagnostic results show that there is a steady-state error, increase the integral gain of speed and torque to eliminate the error;

[0038] If diagnostics indicate overshoot or oscillation, increase the speed and torque derivative gains to improve stability.

[0039] Preferably, the detection unit is used for real-time monitoring after the control module is adjusted, specifically:

[0040] Obtaining key operating data of the frequency converter according to the information of the data acquisition module;

[0041] Pre-process the collected key operation data;

[0042] Set the normal operating range of each key operating data according to the specifications of the inverter;

[0043] Monitor the operating parameters of the inverter in real time, and compare each operating parameter with the set normal operating range. Once the operating parameter exceeds the set normal operating range, it is judged as abnormal;

[0044] When an anomaly is detected, the system immediately generates an alarm signal.

[0045] On the other hand, a frequency converter is proposed, including a central processing unit, an input circuit, an inverter circuit, a drive circuit, a detection circuit, a protection circuit, an operation panel, a heat dissipation system and a communication interface;

[0046] The input circuit is used to convert AC power into DC power;

[0047] The inverter circuit is used to convert the DC voltage into an AC voltage with adjustable frequency;

[0048] The driving circuit is used to control the switch of the inverter circuit;

[0049] The detection circuit is used to detect the operating status of the frequency converter;

[0050] The protection circuit is used to ensure the safe operation of the frequency converter;

[0051] The operation panel is used to provide a user interface;

[0052] The heat dissipation system includes a heat sink and a fan, which are used to ensure heat dissipation of the inverter during operation;

[0053] The communication interface is used to realize the communication of the frequency converter.

[0054] On the other hand, a frequency converter control method is also proposed, comprising the following steps:

[0055] Step 1: Collect parameter information of the inverter and the parameter information of the inverter load;

[0056] Step 2: Adjust the frequency of the inverter output until the frequency of the inverter matches the set frequency of the motor in the load fan;

[0057] Step 3: Monitor the operation of the inverter and inverter load to determine whether there are any abnormalities, and formulate a feedback strategy based on the judgment results.

[0058] Beneficial effects: The data acquisition module monitors the operating status of the inverter in real time. The control module can adjust the output frequency of the inverter based on this information to match the design requirements of the fan and ensure that the fan operates at the optimal working point;

[0059] It can quickly respond to the information provided by the data acquisition module and adjust the output frequency of the inverter in time to adapt to load changes, such as changes in indoor temperature in the air conditioning system;

[0060] The operating status of the inverter can be monitored in real time, fault diagnosis and early warning can be performed, thereby improving the reliability and safety of the system; through early fault detection and diagnosis, the downtime caused by faults can be reduced, the system can quickly adapt to load changes, and improve control accuracy, thereby improving the overall system performance and user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a schematic diagram of a frequency converter of the present invention;

[0062] Figure 2 is a flow chart of the management system of the present invention;

[0063] Figure 3 It is a method diagram of the present invention. DETAILED DESCRIPTION

[0064] Application scenarios: In actual use, the load of the inverter is not limited to a single motor, and it has a wide range of uses. For example, when the load of the inverter is a fan, the speed of the fan may need to run within a specific frequency range to maintain optimal efficiency. If the frequency setting range of the inverter does not match the design requirements of the fan, the fan may not be able to run at the optimal operating point, resulting in reduced fan efficiency and increased energy consumption. Long-term operation may cause additional wear on the motor and fan.

[0065] Moreover, the fan may need to respond quickly to load changes in some applications. For example, in an air-conditioning system, when the indoor temperature changes, the fan speed needs to be adjusted quickly to maintain a constant temperature. If the dynamic response speed of the inverter is insufficient, the fan speed may not be adjusted in time, and the system may not be able to adapt to load changes quickly, resulting in a decrease in control accuracy, which may affect the overall system performance and user experience.

[0066] like Figure 1 As shown: A frequency converter control system, characterized in that it includes a data acquisition module, the data acquisition module is used to collect parameter information of the frequency converter and parameter information of the frequency converter load; it should be noted that, in this embodiment, the parameter information, such as current, voltage and temperature, also includes environmental information of the frequency converter operation and user preset information of the operation panel of the frequency converter;

[0067] It should also be noted that the data acquisition module is associated with the detection circuit and operation panel in the inverter, which can provide real-time data on the inverter's operating status, facilitate the control module to perform precise control, and record user settings to achieve customized operation;

[0068] It should be noted that the control system of the inverter needs to consider many aspects, including hardware selection, control strategy, user interface, communication interface, protection mechanism, etc.;

[0069] A control module, the control module is used to adjust the frequency of the inverter output according to the parameter information of the data acquisition module and the parameter information of the motor in the inverter load fan, until the frequency of the inverter matches the set frequency of the motor in the load fan; it should be noted that to ensure that the fan operates at the best efficiency point, the output frequency of the inverter can be adjusted according to the parameter information of the inverter and its load motor during the use of the inverter, so that the inverter can adapt to different types of common loads;

[0070] It should also be noted that the control module is associated with the central processor in the frequency converter, which can optimize the operating efficiency of the fan and reduce energy consumption by accurately controlling the output frequency of the frequency converter;

[0071] A feedback module, which is used to monitor the operation of the inverter and the inverter load according to the information of the data acquisition module after the control module is adjusted, determine whether there is an abnormality, and formulate a feedback strategy according to the judgment result. It should be noted that the operating status of the inverter can be monitored according to the information of the data acquisition module, fault diagnosis and early warning can be performed, the reliability and safety of the system can be improved, and downtime can be reduced through early fault detection and diagnosis;

[0072] It should also be noted that, through the comprehensive use of the above modules, it is possible to avoid abnormal regulation of the frequency converter by the control module, thereby further increasing the versatility of the frequency converter;

[0073] For example, the inverter and the load motor are installed and connected, and then the inverter's output frequency is automatically adjusted by collecting the inverter's real-time data and the load motor's required frequency, so that the inverter can adapt to loads of different specifications, increasing the inverter's versatility;

[0074] It also includes a communication module, which is used to realize the signal connection between the frequency converter and the control system; it should be noted that the communication module is associated with the communication interface, which can enhance the integration capability of the frequency converter, allow remote monitoring and control, and improve the automation level of the system; the specific working mode of the communication module is as follows:

[0075] It is necessary to determine the information exchanged between the inverter and the control system; it should be noted that the exchanged information includes the inverter status information (such as current, voltage, temperature, frequency, etc.) and control commands (such as start, stop, speed regulation, etc.);

[0076] Select a communication protocol, and perform hardware connection according to the selected communication protocol; it should be noted that in this embodiment, common ones include Modbus, Profibus, CANopen, etc. For example, Modbus is a serial communication protocol suitable for communication between the inverter and the PLC;

[0077] Configure the communication parameters in the inverter and control system. It should be noted that for Modbus, the RS-485 interface of the inverter needs to be connected to the corresponding interface of the PLC. For wireless communication, a wireless communication module needs to be configured.

[0078] Carry out communication measurement to ensure that the communication between the inverter and the control system is normal. It should be noted that the data can be sent and received correctly to verify whether the inverter can perform corresponding operations according to the instructions of the control system.

[0079] As an optional embodiment: the control module includes the following steps:

[0080] The real-time operation data of the inverter is collected through the data acquisition module. It should be noted that in this embodiment, sensors and data acquisition hardware are deployed to monitor the key parameters of the inverter, such as current, voltage, temperature, frequency, etc., to monitor the operation status of the inverter in real time, detect abnormalities in time, and provide accurate data support for subsequent analysis.

[0081] Obtain parameter information of the motor in the load fan; it should be noted that it can be obtained through the target state set by the user (such as the expected speed, frequency, etc.), and it is clear whether the inverter has reached the target state set by the user, providing a basis for control decision-making, wherein the target state set by the user can be obtained through the operation panel;

[0082] The adjusted output frequency of the inverter is obtained through the real-time operation data of the inverter and the parameter information of the motor in the load fan. It should be noted that if the current state is inconsistent with the target state, the frequency value that needs to be adjusted is calculated to ensure that the inverter can respond to the control command in the best way and reduce the system oscillation caused by too fast or too slow frequency adjustment.

[0083] The control module sends a command to the inverter, and adjusts the output frequency to match the load state according to the adjusted output frequency of the inverter. It should be noted that the adjustment command is sent to the inverter through the communication protocol, and safety and reliability measures for command sending, such as command confirmation and error checking, are implemented to quickly and accurately adjust the output of the inverter to meet system requirements and improve the response speed and control accuracy of the system.

[0084] After the adjustment is completed, the real-time operation data of the inverter is collected through the data acquisition module, and the new status is fed back to the control module for analysis. It should be noted that data collection is continued to ensure that the control module can obtain the latest status of the inverter, implement a closed-loop control strategy, further optimize the control instructions according to the feedback data, realize continuous monitoring and control of the inverter, ensure stable operation of the system, and improve the energy efficiency and performance of the entire system through continuous feedback and adjustment.

[0085] As an optional embodiment: the step of obtaining the adjusted output frequency of the frequency converter comprises the following steps:

[0086] Acquire the real-time data of the frequency converter, including the current, voltage and power factor of the motor in the load fan; it should be noted that the above real-time data is obtained through the data acquisition module;

[0087] The torque demand T of the motor in the inverter load fan is obtained; it should be noted that, in this embodiment, the torque demand T can be obtained by multiplying the product of the current of the motor in the load fan by the voltage and the power factor, divided by 9550 and multiplied by the actual speed of the motor;

[0088] Obtain the difference E between the actual speed of the motor in the inverter load fan and the set speed;

[0089] The difference Q between the torque demand T and the actual torque of the motor in the inverter load fan is obtained; it should be noted that the set speed and set torque are obtained through the operation panel;

[0090] The output frequency adjustment value U of the inverter is obtained according to the speed difference E and the torque difference Q. The output frequency of the inverter is adjusted through the PID control algorithm to meet the torque demand and speed control. Specifically:

[0091] Integrate the speed difference to get ∫E(dt), and differentiate the speed difference to get

[0092] Integrating the torque difference gives ∫Q(dt), and differentiating the torque difference gives

[0093] According to the formula Calculate and obtain the adjusted output frequency H of the frequency converter;

[0094] in are the proportional, integral and differential gains of the speed, are the proportional, integral and differential gains of the torque;

[0095] The current frequency of the inverter is added to the output frequency adjustment value U to obtain the adjusted output frequency of the inverter;

[0096] The adjusted output frequency of the frequency converter is transmitted to the central processor to change the output frequency of the frequency converter. It should be noted that the adjusted frequency is fed back to the system, the running status of the motor is continuously monitored, and the above steps are repeated for fine-tuning;

[0097] It should also be noted that through real-time monitoring and adjustment, the motor can be ensured to operate stably under different loads. Through precise control, energy waste can be reduced and the overall energy efficiency of the system can be improved. The closed-loop control strategy can quickly respond to system changes and improve system stability.

[0098] As an optional embodiment: the specific working mode of the feedback module is as follows:

[0099] The fault diagnosis result is obtained according to the parameter information of the data acquisition module, and an early warning mechanism is set according to the fault diagnosis result. When the fault diagnosis result is detected to be abnormal, the system generates an early warning signal; it should be noted that, in this embodiment, the standard range of the fault detection rate G and the false alarm rate K is set in advance, and when the fault detection rate G and the false alarm rate K are not within the standard range, it is judged that the fault diagnosis result is abnormal;

[0100] After the early warning signal is generated, the diagnosis result is fed back to the control module, and the control module adjusts the control strategy according to the diagnosis result. It should be noted that through early fault detection and diagnosis, downtime is reduced, potential safety hazards are discovered and handled in a timely manner, and more effective maintenance plans are formulated based on real-time data and fault records.

[0101] As an optional embodiment: the fault diagnosis result is obtained as follows:

[0102] Subtract the actual speed from the synchronous speed of the motor in the inverter load fan and divide it by the synchronous speed to obtain the slip F of the motor. It should be noted that the slip F reflects the relative speed between the motor rotor and the stator magnetic field and is an important indicator of the motor's operating status.

[0103] The fault detection rate G and the false alarm rate K of the frequency converter are obtained according to the slip F and the torque demand T of the motor, and the fault detection rate G and the false alarm rate K are marked as the fault diagnosis result; it should be noted that, in this embodiment, the fault detection rate G can be obtained by The false alarm rate K is obtained as follows: Among them, FP is false positive, TN is true negative, TP is true positive, and FN is false negative;

[0104] It should also be noted that if a potential fault is identified based on slip and torque demand, then the abnormal values ​​of these parameters can be considered as true positive TP, while the normal values ​​can be considered as false negative FN. Similarly, if normal slip or torque demand is mistakenly identified as a fault, these cases can be considered as false positive FP, while the correctly identified normal cases can be considered as true negative TN;

[0105] The fault detection rate G is the ratio of true positives TP to true positives plus false negatives FN. True positives refer to fault instances correctly identified by the system, while false negatives refer to actual faults that the system fails to identify.

[0106] By maximizing the fault detection rate G, it can be ensured that the fault diagnosis system has a high recognition ability when facing various fault modes;

[0107] The false alarm rate K is the ratio of false positive FP to false positive plus true negative TN. False positive means that the system mistakenly identifies a normal situation as a fault, while true negative means that the system correctly identifies a non-fault situation. By minimizing the false alarm rate K, the occurrence of false alarms can be reduced, thereby improving the accuracy of the fault diagnosis system.

[0108] As an optional embodiment: the specific manner in which the control module adjusts the control strategy according to the diagnosis result is as follows:

[0109] According to the diagnosis results, determine whether it is necessary to adjust the output frequency adjustment value U or shut down for maintenance; it should be noted that if the fault detection rate G is high, it means that most actual faults are correctly identified. If the fault detection rate G suddenly decreases, it may indicate that a new fault has occurred in the system that has not been identified and further inspection is required;

[0110] If the false alarm rate K is high, it means that the system mistakenly identifies many normal situations as faults. If the false alarm rate K continues to be high, the threshold or logic of the diagnostic algorithm needs to be adjusted to reduce false alarms. The fault detection rate G and the false alarm rate K are used to determine whether the output frequency adjustment value U needs to be adjusted or the system needs to be shut down for maintenance. If the fault diagnosis results indicate that the fault is permanent, or the system still cannot run stably after adjusting the PID parameters, it may be necessary to shut down for maintenance.

[0111] As an optional embodiment: the specific manner in which the control module adjusts the control strategy according to the diagnosis result also includes:

[0112] If the output frequency adjustment value U needs to be adjusted, the frequency adjustment value U is adjusted according to the diagnosis result; it should be noted that the diagnosis result can also be obtained by judging the response time and output deviation of the frequency converter;

[0113] If the diagnostic results show a slow response, increase the proportional gain of the speed and torque to increase the response speed; it should be noted that the diagnostic results show a slow response, which means that the system output does not react quickly enough to the input change;

[0114] If the diagnosis result shows that there is a steady-state error, the integral gain of the speed and torque is increased to eliminate the error; it should be noted that the existence of a steady-state error means that the system output deviates from the expected output after reaching a steady state;

[0115] If the diagnostic results show that there is overshoot or oscillation, increase the differential gain of speed and torque to improve stability. It should be noted that through these steps, it can be systematically determined whether the output frequency needs to be adjusted or the machine needs to be shut down for maintenance to ensure the stable operation and safety of the inverter and motor system.

[0116] As an optional embodiment: the detection unit is used for real-time monitoring after the control module is adjusted, specifically:

[0117] The key operating data of the inverter is obtained according to the information of the data acquisition module; it should be noted that the input voltage, output voltage, current, frequency, temperature and power;

[0118] Preprocess the collected key operation data; it should be noted that the collected data is cleaned, denoised and missing data is processed;

[0119] Set the normal operating range of each key operating data according to the specifications of the inverter; it should be noted that the normal operating range is obtained through the specifications and historical data of the inverter;

[0120] Monitor the operating parameters of the inverter in real time, and compare each operating parameter with the set normal operating range. Once the operating parameter exceeds the set normal operating range, it is judged as abnormal;

[0121] When an abnormality is detected, the system immediately generates an alarm signal. It should be noted that the alarm signal can be defined as an alarm or fault output through the inverter's relay output function;

[0122] It should be noted that although the inverter after adjustment by the control module can adapt to different loads, due to the adjustment of the output frequency of the inverter, the operation of the inverter may become abnormal during long-term use. This technical solution monitors the operating data of the inverter in real time, and generates an alarm signal and transmits it to the staff's mobile phone terminal as soon as an abnormality occurs in the inverter.

[0123] The present invention also proposes a frequency converter, including a central processing unit, an input circuit, an inverter circuit, a drive circuit, a detection circuit, a protection circuit, an operation panel, a heat dissipation system and a communication interface;

[0124] The input circuit is used to convert AC power into DC power;

[0125] The inverter circuit is used to convert the DC voltage into an AC voltage with adjustable frequency; it should be noted that the inverter circuit is used to supply the motor;

[0126] The drive circuit is used to control the switch of the inverter circuit; it should be noted that it generates an appropriate motor drive signal;

[0127] The detection circuit is used to detect the operating status of the frequency converter; it should be noted that it includes current and voltage sensors to provide feedback signals;

[0128] The protection circuit is used to ensure the safe operation of the inverter; it should be noted that it includes protection functions such as overcurrent, overvoltage, undervoltage, and overheating;

[0129] The operation panel is used to provide a user interface; it should be noted that it is used for parameter setting, status display and fault diagnosis;

[0130] The heat dissipation system includes a heat sink and a fan, which are used to ensure heat dissipation of the inverter during operation;

[0131] The communication interface is used to realize the communication of the frequency converter. It should be noted that in this embodiment, such as RS485 or CAN bus, it is used to realize the communication between the frequency converter and the PLC or other controllers.

[0132] It should be noted that the frequency converter is a device widely used in the field of industrial automation. It adjusts the speed of the motor by changing the power supply frequency of the motor, thereby achieving precise motor control and energy saving. It is a low-power general-purpose frequency converter;

[0133] It should also be noted that the feedback module also includes a communication monitoring unit, which is used to monitor whether the operation of the communication module is abnormal and perform optimization when it is abnormal, specifically:

[0134] Continuously monitor the communication quality between the inverter and the control system, set thresholds for communication performance indicators, and consider them abnormal if they exceed the thresholds. It should be noted that communication quality includes key indicators such as signal strength, bit error rate, and communication delay;

[0135] Check the packet loss rate and retransmission rate. It should be noted that a high loss rate may indicate unstable communication. Monitor the data retransmission rate. High retransmission frequency may indicate communication quality problems.

[0136] When the above anomalies occur, it is marked as a potential communication problem and the maintenance personnel are notified through the early warning mechanism. It should be noted that a detailed fault report is generated, including the fault type, time, impact range, etc.

[0137] Adjust the communication parameters according to the communication monitoring results; it should be noted that, such as baud rate, data bit, stop bit, etc.;

[0138] Check the communication hardware to ensure that they are working properly; it should be noted that communication hardware includes interface cards, network cables, wireless modules, etc.

[0139] After the communication is interrupted, formulate a backup plan for communication failure. It should be noted that, for example, switching to a backup communication link;

[0140] It should also be noted that it is possible to ensure whether the communication module works abnormally and to optimize effectively when it is abnormal, thereby ensuring stable and reliable communication between the inverter and the control system.

[0141] The present invention also proposes a frequency converter control method, comprising the following steps:

[0142] Step 1: Collect parameter information of the inverter and the parameter information of the inverter load;

[0143] Step 2: Adjust the frequency of the inverter output until the frequency of the inverter matches the set frequency of the motor in the load fan;

[0144] Step 3: Monitor the operation of the inverter and inverter load to determine whether there are any abnormalities, and formulate a feedback strategy based on the judgment results

[0145] How it works

[0146] The data acquisition module monitors the operating status of the inverter in real time. The control module can adjust the output frequency of the inverter based on this information to match the design requirements of the fan and ensure that the fan operates at the optimal working point.

[0147] It can quickly respond to the information provided by the data acquisition module and adjust the output frequency of the inverter in time to adapt to load changes, such as changes in indoor temperature in the air conditioning system;

[0148] The operating status of the inverter can be monitored in real time, fault diagnosis and early warning can be performed, thereby improving the reliability and safety of the system; through early fault detection and diagnosis, the downtime caused by faults can be reduced, the system can quickly adapt to load changes, and improve control accuracy, thereby improving the overall system performance and user experience.

[0149] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technical staff in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of this template.

Claims

1. A frequency converter control system, characterized in that: It includes a data acquisition module, which is used to collect parameter information of the frequency converter and parameter information of the frequency converter load; A control module, the control module is used to adjust the frequency output by the inverter according to the parameter information of the data acquisition module and the parameter information of the motor in the inverter load fan, until the frequency of the inverter matches the set frequency of the motor in the load fan; A feedback module is used to monitor the operation of the inverter and the inverter load according to the information of the data acquisition module after the control module is adjusted, to determine whether there is an abnormality, and to formulate a feedback strategy according to the judgment result.

2. A frequency converter control system according to claim 1, characterized in that: The control module comprises the following steps: Collect the real-time operation data of the inverter through the data acquisition module; Obtain parameter information of the motor in the load fan; The adjusted output frequency of the inverter is obtained through the real-time operation data of the inverter and the parameter information of the motor in the load fan; The control module sends a command to the frequency converter, and adjusts the output frequency to match the load state according to the adjusted output frequency of the frequency converter; After the adjustment is completed, the real-time operation data of the inverter continues to be collected through the data acquisition module, and the new status is fed back to the control module for analysis.

3. A frequency converter control system according to claim 2, characterized in that: The step of obtaining the adjusted output frequency of the frequency converter comprises the following steps: Obtain real-time data of the inverter, including the current, voltage and power factor of the motor in the load fan; Obtain the torque requirement T of the motor in the inverter load fan; Obtain the difference E between the actual speed of the motor in the inverter load fan and the set speed; Obtain the difference Q between the torque demand T and the actual torque of the motor in the inverter load fan; The output frequency adjustment value U of the inverter is obtained according to the speed difference E and the torque difference Q. The output frequency of the inverter is adjusted by the PID control algorithm to meet the torque demand and speed control. Specifically: Integrate the speed difference to get ∫E(dt), and differentiate the speed difference to get Integrating the torque difference gives ∫Q(dt), and differentiating the torque difference gives According to the formula Calculate and obtain the adjusted output frequency H of the frequency converter; in and are the proportional, integral and differential gains of the speed, and are the proportional, integral and differential gains of the torque; The current frequency of the inverter is added to the output frequency adjustment value U to obtain the adjusted output frequency of the inverter; The adjusted output frequency of the frequency converter is transmitted to the central processing unit to change the output frequency of the frequency converter.

4. A frequency converter control system according to claim 1, characterized in that: The feedback module works as follows: Obtaining a fault diagnosis result according to the parameter information of the data acquisition module, setting an early warning mechanism according to the fault diagnosis result, and generating an early warning signal when detecting that the fault diagnosis result is abnormal; After the early warning signal is generated, the diagnosis result is fed back to the control module, and the control module adjusts the control strategy according to the diagnosis result.

5. A frequency converter control system according to claim 4, characterized in that: The method for obtaining the fault diagnosis result is as follows: Subtract the actual speed from the synchronous speed of the motor in the inverter load fan and divide it by the synchronous speed to obtain the motor slip F; The fault detection rate G and the false alarm rate K of the frequency converter are obtained according to the slip F and the torque demand T of the motor, and the fault detection rate G and the false alarm rate K are marked as the fault diagnosis result.

6. A frequency converter control system according to claim 4, characterized in that: The specific manner in which the control module adjusts the control strategy according to the diagnosis result is as follows: Based on the diagnosis results, determine whether it is necessary to adjust the output frequency adjustment value U or shut down for maintenance.

7. A frequency converter control system according to claim 6, characterized in that: The specific manner in which the control module adjusts the control strategy according to the diagnosis result also includes: If the output frequency adjustment value U needs to be adjusted, the frequency adjustment value U is adjusted according to the diagnosis result; If the diagnostic results indicate a slow response, increase the proportional gains of speed and torque to improve the response; If the diagnostic results show that there is a steady-state error, increase the integral gain of speed and torque to eliminate the error; If diagnostics indicate overshoot or oscillation, increase the speed and torque derivative gains to improve stability.

8. A frequency converter control system according to claim 4, characterized in that: The detection unit is used for real-time monitoring after the control module is adjusted, specifically: Obtaining key operating data of the frequency converter according to the information of the data acquisition module; Pre-process the collected key operation data; Set the normal operating range of each key operating data according to the specifications of the inverter; Monitor the operating parameters of the inverter in real time, and compare each operating parameter with the set normal operating range. Once the operating parameter exceeds the set normal operating range, it is judged as abnormal; When an anomaly is detected, the system immediately generates an alarm signal.

9. A frequency converter, applicable to the frequency converter control system according to claim 1, characterized in that: It includes a central processing unit, input circuit, inverter circuit, drive circuit, detection circuit, protection circuit, operation panel, cooling system and communication interface; The input circuit is used to convert AC power into DC power; The inverter circuit is used to convert the DC voltage into an AC voltage with adjustable frequency; The driving circuit is used to control the switch of the inverter circuit; The detection circuit is used to detect the operating status of the frequency converter; The protection circuit is used to ensure the safe operation of the frequency converter; The operation panel is used to provide a user interface; The heat dissipation system includes a heat sink and a fan, which are used to ensure heat dissipation of the inverter during operation; The communication interface is used to realize the communication of the frequency converter.

10. A frequency converter control method, characterized in that: The following steps are involved: Step 1: Collect parameter information of the inverter and the parameter information of the inverter load; Step 2: Adjust the frequency of the inverter output until the frequency of the inverter matches the set frequency of the motor in the load fan; Step 3: Monitor the operation of the inverter and inverter load to determine whether there are any abnormalities, and formulate a feedback strategy based on the judgment results.

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