Frequency converter protection method and system

Abstract

Disclosed is a frequency converter protection method, comprising: acquiring the current value of a frequency converter and a duration of the current value; on the basis of the current value and the duration of the current value, determining whether the frequency converter is running normally; when the frequency converter is running normally, acquiring the real-time power of a motor at an output end of the frequency converter; comparing the real-time power with a preset power, determining the power difference between the real-time power and the preset power, and adjusting the output voltage and output frequency of the frequency converter on the basis of the power difference; acquiring the working temperature of the frequency converter, and correcting the working temperature on the basis of the current value and the adjusted output voltage to obtain a final working temperature; and determining protection for the frequency converter on the basis of the final working temperature. Current protection and voltage protection are achieved, and temperature protection is also achieved on the basis of the working temperature, thereby guaranteeing safe running of frequency converters.

Description

A protection method and system for a frequency converter Technical Field

[0001] The present invention relates to the technical field of frequency converters, and in particular to a protection method and system for a frequency converter. Background Art

[0002] A frequency converter (VFD) is a power control device that utilizes frequency conversion and microelectronics technology to control AC motors by varying the motor's operating power supply frequency. VFDs can implement various control methods for motors, including soft starting, multi-speed operation, and low-speed, high-efficiency operation. Different operating conditions can be achieved by adjusting the VFD's parameters to meet specific requirements.

[0003] However, during the operation of the inverter, overcurrent, overvoltage, or heat generated by long-term use will cause damage to the inverter. Therefore, a protection method for the inverter is urgently needed to reduce the damage to the inverter. Summary of the Invention

[0004] The purpose of the present invention is to provide a protection method for a frequency converter, so as to solve the problem that the frequency converter is damaged due to excessive heat generated during long-term use or excessive current during operation.

[0005] The present invention provides a protection method for a frequency converter, comprising:

[0006] Obtaining the current value of the inverter and the duration of the current value;

[0007] determining whether the inverter is operating normally according to the current value and the duration of the current value;

[0008] When the frequency converter is operating normally, obtaining the real-time power of the motor at the output end of the frequency converter;

[0009] Comparing the real-time power with the preset power, determining a power difference between the real-time power and the preset power, and adjusting the output voltage and output frequency of the inverter according to the power difference;

[0010] Acquiring an operating temperature of the inverter, and correcting the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature;

[0011] Protection for the frequency converter is determined according to the final operating temperature.

[0012] In some embodiments of the present application, determining whether the inverter operates normally according to the current value and the duration of the current value includes:

[0013] If the current value is greater than the first set current value and the duration of the current value is greater than the first set duration, it is determined that the inverter is operating abnormally;

[0014] If the current value is greater than a second set current value and the duration of the current value is greater than the second set duration, it is determined that the inverter is operating abnormally;

[0015] The first set current value is greater than the second set current value, and the first set duration is less than the second set duration.

[0016] In some embodiments of the present application, determining whether the frequency converter is operating normally further includes:

[0017] If the current value is greater than the first set current value for a number of times greater than a first set number, it is determined that the inverter is operating abnormally;

[0018] If the current value is greater than the second set current value for a number of times greater than a second set number, it is determined that the inverter is operating abnormally;

[0019] The first set number of times is smaller than the second set number of times.

[0020] In some embodiments of the present application, after comparing the real-time power with the preset power, the following steps are included:

[0021] If the real-time power is equal to the preset power, it is determined that the operation of the inverter meets the set standard;

[0022] If the implemented power is greater than the preset power, it is determined that the operation of the inverter does not meet the set standard, and the power difference between the real-time power and the preset power is determined, and the output voltage and output frequency of the inverter are adjusted according to the power difference.

[0023] In some embodiments of the present application, a first power difference interval (P1, P2), a second power difference interval (P2, P3), a third power difference interval (P3, P4), a first voltage adjustment coefficient a1, a second voltage adjustment coefficient a2, and a third voltage adjustment coefficient a3 are preset, wherein P1 < P2 < P3 < P4, 1 < a1 < a2 < a3 < 1.2;

[0024] Adjusting the output voltage U of the frequency converter according to the power difference;

[0025] When the power difference is within the first power difference interval (P1, P2), the first voltage adjustment coefficient a1 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a1;

[0026] When the power difference is within the second power difference range (P2, P3), the second voltage adjustment coefficient a2 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a2;

[0027] When the power difference is in the third power difference interval (P3, P4), the third voltage adjustment coefficient a3 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a3.

[0028] In some embodiments of the present application, a first frequency adjustment coefficient b1, a second frequency adjustment coefficient b2, and a third frequency adjustment coefficient b3 are preset, wherein 1<b1<b2<b3<1.2;

[0029] Adjusting the output frequency F of the frequency converter according to the power difference;

[0030] When the power difference is within the first power difference interval (P1, P2), the first frequency adjustment coefficient b1 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b1;

[0031] When the power difference is within the second power difference range (P2, P3), the second frequency adjustment coefficient b2 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b2;

[0032] When the power difference is in the third power difference interval (P3, P4), the third frequency adjustment coefficient b3 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b3.

[0033] In some embodiments of the present application, the final operating temperature is calculated according to the following formula:

[0034] ;

[0035] in, is the final operating temperature, is the operating temperature of the inverter, is the influence coefficient of the inverter itself on the final operating temperature, is the output voltage of the inverter after adjustment, is the current value of the inverter, is the inverter running time, is the influence coefficient of room temperature on the final operating temperature, is the room temperature of the inverter environment.

[0036] In some embodiments of the present application, determining protection for the inverter according to the final operating temperature includes:

[0037] comparing the final operating temperature to a temperature threshold;

[0038] If the final operating temperature is greater than the temperature threshold, a protection instruction is output to control the inverter to shut down.

[0039] The present invention also discloses a protection system for a frequency converter, comprising:

[0040] An acquisition module, the acquisition module is used to obtain the current value of the inverter and the duration of the current value, as well as the operating temperature of the inverter and the real-time power of the motor at the output end of the inverter when the inverter is operating normally;

[0041] A frequency converter operation judgment module, the frequency converter operation judgment module is used to judge whether the frequency converter is operating normally according to the current value and the duration of the current value;

[0042] a voltage-frequency adjustment module, configured to compare the real-time power with a preset power, determine a power difference between the real-time power and the preset power, and adjust the output voltage and output frequency of the inverter according to the power difference;

[0043] a temperature determination module, configured to correct the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature;

[0044] A protection module is used to determine protection for the inverter according to the final operating temperature.

[0045] In some embodiments of the present application, the acquisition module includes:

[0046] A current detector, connected to the frequency converter, for detecting the current value of the frequency converter and the duration of the current value;

[0047] A temperature detector is provided in the inverter and is used to detect the operating temperature of the inverter;

[0048] A power detector is connected to the motor at the output end of the inverter and is used to detect the real-time power of the motor at the output end of the inverter when the inverter is operating normally.

[0049] The present invention detects the current value of the inverter to determine whether the inverter is operating normally, implements current protection of the inverter, ensures the safe operation of the inverter, detects the real-time power of the output end motor when the inverter is operating normally, determines that the operation of the inverter meets the set standards, and corrects the operating temperature according to the current value and the adjusted output voltage to obtain the final operating temperature. The protection of the inverter is determined according to the final operating temperature, and the inverter is shut down in time to prevent long-term operation from generating heat and causing the temperature to rise, thereby avoiding damage to the inverter, thereby greatly improving the stability of the inverter.

[0050] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG1 is a flow chart of a method for protecting a frequency converter according to the present invention;

[0052] FIG2 is a schematic structural diagram of a protection system for a frequency converter according to the present invention. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0054] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0055] It should be noted that the terms used herein are intended only to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular is intended to include the plural. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof, and do not exclude other elements or objects. The terms "first," "second," and similar terms used in the present invention do not denote any order, quantity, or importance, but are simply used to distinguish between different components. Terms such as "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "side," and "bottom" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are merely relative terms defined to facilitate the description of the structural relationships between the various components or elements of the present invention and do not specifically refer to any particular component or element in the invention and should not be construed as limiting the invention. Terms such as "fixed," "connected," and "connected" should be interpreted broadly to mean that a connection can be fixed, integral, or detachable; it can be direct or indirect through an intermediary. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention based on specific circumstances, and they should not be understood as limitations on the present invention. Example

[0056] The present invention provides a protection method for a frequency converter, as shown in FIG1 , comprising:

[0057] S1, obtaining the current value of the inverter and the duration of the current value.

[0058] S2, judging whether the inverter operates normally according to the current value and the duration of the current value.

[0059] S3, when the frequency converter is operating normally, obtaining the real-time power of the motor at the output end of the frequency converter.

[0060] S4, comparing the real-time power with the preset power, determining a power difference between the real-time power and the preset power, and adjusting the output voltage and output frequency of the inverter according to the power difference.

[0061] S5, obtaining the operating temperature of the inverter, and correcting the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature.

[0062] S6, determining protection for the inverter according to the final operating temperature.

[0063] In some embodiments of the present application, a method for determining whether the inverter is operating normally is disclosed, wherein determining whether the inverter is operating normally according to the current value and the duration of the current value includes:

[0064] If the current value is greater than the first set current value and the duration of the current value is greater than the first set duration, it is determined that the inverter is operating abnormally.

[0065] If the current value is greater than a second set current value and the duration of the current value is greater than the second set duration, it is determined that the inverter is operating abnormally.

[0066] The first set current value is greater than the second set current value, and the first set duration is less than the second set duration.

[0067] In this embodiment, the inverter primarily consists of a rectifier (AC to DC), a filter, an inverter (DC to AC), a braking unit, a drive unit, a detection unit, and a microprocessor. The inverter adjusts the output power voltage and frequency by switching its internal IGBTs, providing the required power voltage based on the motor's actual needs, thereby achieving energy savings and speed regulation. The inverter components in the inverter have poor overload capacity. If the current is excessive or remains above the rated current for a long period during operation, the inverter can easily burn out. Therefore, it is necessary to configure the inverter with a current protection function. By setting a first set current value, a second set current value, a first set duration, and a second set duration, the inverter is able to determine whether it is operating properly and ensure that the current value remains within a reasonable range.

[0068] In some embodiments of the present application, a method for determining whether the inverter is operating normally is disclosed, wherein determining whether the inverter is operating normally further includes:

[0069] If the current value is greater than the first set current value for a number of times greater than a first set number, it is determined that the inverter is operating abnormally.

[0070] If the current value is greater than the second set current value for a number of times greater than a second set number, it is determined that the inverter is operating abnormally.

[0071] The first set number of times is smaller than the second set number of times.

[0072] In this embodiment, if the current value of the inverter increases frequently but for a short period of time, it may also cause the inverter to burn out. Therefore, by setting the first set number of times and the second set number of times, it is judged whether the inverter is operating normally, thereby realizing the current protection of the inverter and ensuring the safe operation of the inverter.

[0073] In some embodiments of the present application, after comparing the real-time power with the preset power, the following steps are included:

[0074] If the real-time power is equal to the preset power, it is determined that the operation of the inverter meets the set standard.

[0075] If the implemented power is greater than the preset power, it is determined that the operation of the inverter does not meet the set standard, and the power difference between the real-time power and the preset power is determined, and the output voltage and output frequency of the inverter are adjusted according to the power difference.

[0076] In this embodiment, by comparing the real-time power of the motor at the output end of the inverter with the preset power, it is determined whether the operation of the inverter meets the set standard. When it does not meet the set standard, the output voltage and output frequency of the inverter are adjusted in time according to the power difference between the real-time power and the preset power to avoid damage to the components in the inverter due to inverter output failure, thereby protecting the inverter.

[0077] In some embodiments of the present application, a specific method for adjusting the output voltage of an inverter according to a power difference is disclosed, wherein a first power difference interval (P1, P2), a second power difference interval (P2, P3), a third power difference interval (P3, P4), a first voltage adjustment coefficient a1, a second voltage adjustment coefficient a2, and a third voltage adjustment coefficient a3 are preset, wherein P1<P2<P3<P4, 1<a1<a2<a3<1.2.

[0078] The output voltage U of the frequency converter is adjusted according to the power difference.

[0079] When the power difference is in the first power difference interval (P1, P2), the first voltage adjustment coefficient a1 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a1.

[0080] When the power difference is in the second power difference range (P2, P3), the second voltage adjustment coefficient a2 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a2.

[0081] When the power difference is in the third power difference interval (P3, P4), the third voltage adjustment coefficient a3 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a3.

[0082] In this embodiment, by setting several power difference intervals and several voltage adjustment coefficients, the corresponding voltage adjustment coefficient is selected according to the power difference interval in which the power difference is located, and the output voltage of the inverter is adjusted to make the entire circuit unobstructed and avoid damage to the inverter due to voltage problems.

[0083] In some embodiments of the present application, a specific method for adjusting the output frequency of the inverter according to the power difference is disclosed, and a first frequency adjustment coefficient b1, a second frequency adjustment coefficient b2, and a third frequency adjustment coefficient b3 are preset, wherein 1<b1<b2<b3<1.2.

[0084] The output frequency F of the frequency converter is adjusted according to the power difference.

[0085] When the power difference is in the first power difference interval (P1, P2), the first frequency adjustment coefficient b1 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b1.

[0086] When the power difference is in the second power difference range (P2, P3), the second frequency adjustment coefficient b2 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b2.

[0087] When the power difference is in the third power difference interval (P3, P4), the third frequency adjustment coefficient b3 is selected to adjust the output frequency F of the inverter, and the output voltage after adjustment is F*b3.

[0088] In this embodiment, by setting several power difference intervals and several frequency adjustment coefficients, the corresponding frequency adjustment coefficient is selected according to the power difference interval in which the power difference is located, and the output electrical frequency of the inverter is adjusted to make the entire circuit unobstructed and avoid damage to the inverter due to frequency problems.

[0089] Meanwhile, if the ratio of the output voltage to the output frequency is set to a first ratio, the ratio of the adjusted output voltage to the adjusted output frequency is also the first ratio.

[0090] In some embodiments of the present application, a method for determining the final operating temperature is disclosed. The final operating temperature is calculated according to the following formula:

[0091] ;

[0092] in, is the final operating temperature, is the operating temperature of the inverter, is the influence coefficient of the inverter itself on the final operating temperature, is the output voltage of the inverter after adjustment, is the current value of the inverter, is the inverter running time, is the influence coefficient of room temperature on the final operating temperature, is the room temperature of the inverter environment.

[0093] In this embodiment, the temperature detector detects the internal ambient temperature of the inverter, which has a certain error from the operating temperature of the inverter components. Therefore, the operating temperature of the inverter is corrected by the current value and the adjusted output voltage of the inverter to ensure the accuracy of the final operating temperature. In addition, the influence coefficient of the inverter itself on the final operating temperature is The influence coefficient of room temperature on the final working temperature It is obtained based on experiments.

[0094] In some embodiments of the present application, determining protection for the inverter according to the final operating temperature includes:

[0095] The final operating temperature is compared to a temperature threshold.

[0096] If the final operating temperature is greater than the temperature threshold, a protection instruction is output to control the inverter to shut down.

[0097] In this embodiment, the temperature protection of the frequency converter is achieved by comparing the final operating temperature with the temperature threshold.

[0098] The present invention also discloses a frequency converter protection system using the frequency converter protection method, as shown in FIG2 , comprising:

[0099] The acquisition module is used to obtain the current value of the inverter and the duration of the current value, as well as the operating temperature of the inverter and the real-time power of the motor at the output end of the inverter when the inverter is operating normally.

[0100] The inverter operation judgment module is used to judge whether the inverter is operating normally according to the current value and the duration of the current value.

[0101] The voltage-frequency adjustment module is used to compare the real-time power with the preset power, determine the power difference between the real-time power and the preset power, and adjust the output voltage and output frequency of the inverter according to the power difference.

[0102] A temperature determination module is used to correct the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature.

[0103] A protection module is used to determine protection for the inverter according to the final operating temperature.

[0104] In some embodiments of the present application, the acquisition module includes:

[0105] A current detector is connected to the frequency converter and is used to detect the current value of the frequency converter and the duration of the current value.

[0106] A temperature detector is provided in the inverter and is used to detect the operating temperature of the inverter.

[0107] A power detector is connected to the motor at the output end of the inverter and is used to detect the real-time power of the motor at the output end of the inverter when the inverter is operating normally.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

[0109] The system provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiment can be combined into one module or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps and are not to be regarded as improper limitations of the present invention.

[0110] Those skilled in the art should be able to appreciate that, in conjunction with the modules and method steps of each example described in the embodiments disclosed herein, it is possible to implement them with electronic hardware, computer software, or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

Claims

1. A protection method for a frequency converter, characterized in that: include: Obtaining a current value of the frequency converter and a duration of the current value; Determining whether the frequency converter is operating normally according to the current value and the duration of the current value; When the frequency converter is operating normally, obtaining the real-time power of the motor at the output end of the frequency converter; Compare the real-time power with the preset power, determine the power difference between the real-time power and the preset power, and adjust the output voltage and output frequency of the inverter according to the power difference; Acquiring the operating temperature of the inverter, and correcting the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature; The protection of the frequency converter is determined according to the final operating temperature.

2. A method for protecting a frequency converter according to claim 1, characterized in that: Judging whether the inverter is operating normally according to the current value and the duration of the current value includes: If the current value is greater than the first set current value and the duration of the current value is greater than the first set duration, it is determined that the frequency converter is operating abnormally; If the current value is greater than the second set current value and the duration of the current value is greater than the second set duration, it is determined that the inverter is operating abnormally; The first set current value is greater than the second set current value, and the first set duration is less than the second set duration.

3. A method for protecting a frequency converter according to claim 2, characterized in that: Determining whether the frequency converter is operating normally also includes: If the current value is greater than the first set current value for a number of times greater than a first set number of times, determining that the frequency converter is operating abnormally; If the current value is greater than the second set current value for a number of times greater than a second set number of times, determining that the frequency converter is operating abnormally; The first set number of times is smaller than the second set number of times.

4. The inverter protection method according to claim 1, characterized in that: After comparing the real-time power with the preset power, the method further comprises: If the real-time power is equal to the preset power, it is determined that the operation of the frequency converter meets the set standard; If the implemented power is greater than the preset power, it is determined that the operation of the inverter does not meet the set standard, and the power difference between the real-time power and the preset power is determined, and the output voltage and output frequency of the inverter are adjusted according to the power difference.

5. A method for protecting a frequency converter according to claim 4, characterized in that: A first power difference interval (P1, P2), a second power difference interval (P2, P3), a third power difference interval (P3, P4), a first voltage adjustment coefficient a1, a second voltage adjustment coefficient a2, and a third voltage adjustment coefficient a3 are preset, wherein P1<P2<P3<P4, 1<a1<a2<a3<1.2; Adjusting the output voltage U of the frequency converter according to the power difference; When the power difference is in the first power difference interval (P1, P2), the first voltage adjustment coefficient a1 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a1; When the power difference is in the second power difference interval (P2, P3), the second voltage adjustment coefficient a2 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a2; When the power difference is in the third power difference interval (P3, P4), the third voltage adjustment coefficient a3 is selected to adjust the output voltage U of the inverter, and the adjusted output voltage is U*a3.

6. A method for protecting a frequency converter according to claim 5, characterized in that: A first frequency adjustment coefficient b1, a second frequency adjustment coefficient b2, and a third frequency adjustment coefficient b3 are preset, wherein 1<b1<b2<b3<1.2; Adjusting the output frequency F of the frequency converter according to the power difference; When the power difference is in the first power difference interval (P1, P2), the first frequency adjustment coefficient b1 is selected to adjust the output frequency F of the inverter, and the adjusted output voltage is F*b1; When the power difference is in the second power difference interval (P2, P3), the second frequency adjustment coefficient b2 is selected to adjust the output frequency F of the inverter, and the adjusted output voltage is F*b2; When the power difference is in the third power difference interval (P3, P4), the third frequency adjustment coefficient b3 is selected to adjust the output frequency F of the inverter, and the adjusted output voltage is F*b3.

7. The inverter protection method according to claim 1, characterized in that: The final operating temperature is calculated according to the following formula: ； in, is the final operating temperature, is the operating temperature of the inverter, is the influence coefficient of the inverter itself on the final operating temperature, is the output voltage of the inverter after adjustment, is the current value of the inverter, is the inverter running time, is the influence coefficient of room temperature on the final working temperature, is the room temperature of the inverter.

8. The inverter protection method according to claim 1, characterized in that: Determining the protection of the frequency converter according to the final operating temperature includes: comparing the final operating temperature to a temperature threshold; If the final operating temperature is greater than the temperature threshold, a protection instruction is output to control the inverter to shut down.

9. A protection system for a frequency converter, characterized in that: include: An acquisition module, the acquisition module is used to acquire the current value of the inverter and the duration of the current value, as well as the operating temperature of the inverter and the real-time power of the motor at the output end of the inverter when the inverter is operating normally; A frequency converter operation judgment module, the frequency converter operation judgment module is used to judge whether the frequency converter is operating normally according to the current value and the duration of the current value; A voltage-frequency adjustment module, the voltage-frequency adjustment module is used to compare the real-time power with the preset power, determine the power difference between the real-time power and the preset power, and adjust the output voltage and output frequency of the inverter according to the power difference; a temperature determination module, the temperature determination module being used to correct the operating temperature according to the current value and the adjusted output voltage to obtain a final operating temperature; A protection module is used to determine protection for the frequency converter according to the final operating temperature.

10. The inverter protection system according to claim 9, characterized in that: The acquisition module comprises: A current detector, which is connected to the frequency converter and is used to detect the current value of the frequency converter and the duration of the current value; A temperature detector, which is arranged in the frequency converter and is used to detect the operating temperature of the frequency converter; A power detector is connected to the motor at the output end of the inverter and is used to detect the real-time power of the motor at the output end of the inverter when the inverter is operating normally.

Images