Motor Loss Diagnosis Method and Motor Loss Diagnosis System Using the Same

Abstract

The present invention relates to a method and a system for diagnosing motor losses. More specifically, the purpose is to provide a method and a system for diagnosing motor losses that can diagnose individual losses of a motor so as to improve the motor efficiency. The method for diagnosing motor losses according to one aspect of the present invention includes a data input step, an individual loss analysis step, an efficiency calculation step, a loss rate evaluation step, and an output step. The data input step receives the input of the operating data of the motor in order to measure the efficiency of the motor. The individual loss analysis step uses the operating data to calculate the individual loss rates of the core loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor. The efficiency calculation step uses the individual loss rates calculated in the individual loss analysis step to calculate the efficiency of the motor. The loss rate evaluation step calculates the degree to which the individual loss rates calculated in the individual loss analysis step exceed the average value of the data from a database storing the individual loss rate data of motors that meet the reference efficiency. The output step outputs the efficiency calculated in the efficiency calculation step and the degree of excess calculated in the loss rate evaluation step. According to the present invention, the individual loss rates of the core loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor are shown. Thus, it is possible to know not only which individual loss rate causes the low efficiency of the motor, but also which part of the motor should be improved to increase the motor efficiency.

Description

Technical Field

[0001] The present invention relates to a method and system for diagnosing motor losses. More specifically, an object of the present invention is to provide a method and system for diagnosing motor losses that can diagnose individual losses of a motor so as to improve the efficiency of the motor. Background Art

[0002] A motor is a device that converts electrical energy into mechanical energy. Therefore, high-efficiency motors are required to reduce energy costs and carbon emissions. For this purpose, since July 1, 2008, a minimum efficiency system for mandatory use of high-efficiency motors has been implemented for three-phase induction motors with a power of more than 37 kW and less than 200 kW. Moreover, since January 1, 2010, a minimum efficiency system has also been implemented for small-capacity three-phase induction motors with a power of more than 0.75 kW and less than 37 kW.

[0003] This minimum efficiency system is not only implemented in Korea but also worldwide. Therefore, if a motor does not meet the reference efficiency, it cannot be sold not only in Korea but also in many countries such as the United States, Canada, Australia, the European Union, China, and Japan.

[0004] Therefore, after a motor is produced, it is necessary to measure the efficiency of the motor. The efficiency of the motor is calculated by measuring operating data such as voltage, current, active power, temperature, torque, and rotational speed during motor operation.

[0005] Korean Patent No. 10-0944394 (authorized on February 19, 2010)

[0006] Korean Patent No. 10-0542893 (authorized on January 5, 2006) Summary of the Invention

[0007] Technical Problem

[0008] In the past, by measuring the operating data of a motor and calculating the efficiency of the motor, it was only determined whether the motor meets the reference efficiency. Therefore, when the motor does not meet the reference efficiency, it is redesigned and the efficiency of the motor is measured again. In this case, only measuring the efficiency of the motor has the problem that it is not known where to improve in order to increase the efficiency of the motor.

[0009] The present invention is for solving the above problems. An object of the present invention is to provide a method and system for diagnosing motor losses that can identify factors affecting the efficiency of the motor while measuring the efficiency of the motor so as to improve the efficiency of the motor.

[0010] Solution to the Problem

[0011] The motor loss diagnosis method according to one aspect of the present invention includes a data input step, an individual loss analysis step, an efficiency calculation step, a loss rate evaluation step, and an output step. The data input step receives the input of the operating data of the motor in order to measure the efficiency of the motor. The individual loss analysis step uses the operating data to calculate the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor. The efficiency calculation step uses the individual loss rates calculated in the individual loss analysis step to calculate the efficiency of the motor. The loss rate evaluation step calculates the degree to which the individual loss rates calculated in the individual loss analysis step exceed the average value of the data stored in the database storing the individual loss rate data of the motors satisfying the reference efficiency. The output step outputs the efficiency calculated in the efficiency calculation step and the degree of excess calculated in the loss rate evaluation step.

[0012] In addition, in the motor loss diagnosis method, it is preferable that the output step outputs in such a manner that it is possible to know whether the degree of excess calculated in the loss rate evaluation step exceeds the standard deviation from the average value.

[0013] In addition, it is preferable that the motor loss diagnosis method further includes a data storage step of storing the individual loss rates calculated in the individual loss analysis step in the database when the efficiency calculated in the efficiency calculation step is equal to or higher than the reference efficiency.

[0014] On the other hand, the motor loss diagnosis system according to another aspect of the present invention includes a data input module, an individual loss analysis module, an efficiency calculation module, a storage module, a loss rate evaluation module, and an output module. The data input module receives the input of the operating data of the motor in order to measure the efficiency of the motor. The individual loss analysis module uses the operating data to calculate the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor. The efficiency calculation module uses the individual loss rates calculated by the individual loss analysis module to calculate the efficiency of the motor. The storage module has a database that stores the data of the individual loss rates of the motors satisfying the reference efficiency. The loss rate evaluation module calculates the degree to which the individual loss rates calculated by the individual loss analysis module exceed the average value of the data stored in the database. The output module outputs the efficiency calculated by the efficiency calculation module and the degree of excess calculated by the loss rate evaluation module.

[0015] In addition, in the motor loss diagnosis system, it is preferable that the output module outputs in such a manner that it is possible to know whether the degree of excess calculated by the loss rate evaluation module exceeds the standard deviation from the average value.

[0016] In addition, in the motor loss diagnosis system described above, preferably when the efficiency calculated by the efficiency calculation module is above the reference efficiency, the storage module stores the individual loss rate calculated by the individual loss analysis module in the database.

[0017] Advantages of the Invention

[0018] According to the present invention, the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor are shown. Therefore, it is possible to not only know which individual loss rate causes the low efficiency of the motor, but also know which part of the motor should be improved to increase the efficiency of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a conceptual diagram of an embodiment of a motor loss diagnosis system according to the present invention,

[0020] Figure 2 is a conceptual diagram of a method for diagnosing the loss of a motor using Figure 1 an embodiment,

[0021] Figure 3 and Figure 4 is an example of an output module implementing an output step of Figure 1 an embodiment.

[0022] 1: Motor, 10: Motor loss diagnosis system, 11: Data input module, 13: Individual loss analysis module, 15: Efficiency calculation module, 17: Storage module, 19: Loss rate evaluation module, 21: Output module. DETAILED DESCRIPTION

[0023] With reference to Figures 1 to 4 , an embodiment of a motor loss diagnosis system according to the present invention and a method for diagnosing motor loss using the diagnosis system will be described.

[0024] The motor loss diagnosis system 10 according to the present invention includes a data input module 11, an individual loss analysis module 13, an efficiency calculation module 15, a storage module 17, a loss rate evaluation module 19, and an output module 21.

[0025] The input module 11 receives the input of the operating data of the motor 1 in order to measure the efficiency of the motor 1. The operating data for measuring the efficiency includes the voltage, current, active power, temperature, torque, rotational speed, etc. of the motor during operation. The efficiency of the motor 1 is calculated by receiving the input of these data. In order to receive the input of these data, a resistance meter, a temperature recorder, a power analyzer, etc. are installed in the motor 1.

[0026] The individual loss analysis module 13 calculates individual loss rates such as the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor 1 in the drive using these operating data input from the input module 11.

[0027] The efficiency calculation module 15 calculates the efficiency of the motor 1 under inspection using the individual loss rates calculated by the individual loss analysis module 13. The method of calculating the individual loss rates using these operating data and the method of calculating the efficiency of the motor using the individual loss rates are both well-known methods, so detailed descriptions are omitted. After the efficiency calculation module 15 calculates the efficiency of the motor, it can be known whether the motor meets the reference efficiency.

[0028] The storage module 17 has a database that stores data on the individual loss rates of motors that meet the reference efficiency. That is, the database stores the individual loss rates of multiple motors that meet the reference efficiency through performance tests of the motors. At this time, the average value and standard deviation of each individual loss rate can be known. Thus, the average value and standard deviation of the individual loss rates of motors that meet the reference efficiency can be known. On the other hand, when the efficiency of the motor calculated by the efficiency calculation module 15 meets the reference efficiency, the storage module 17 stores the individual loss rates calculated by the individual loss analysis module 13 in the database and updates the data on the individual loss rates.

[0029] The loss rate evaluation module 19 calculates the degree to which the individual loss rates calculated by the individual loss analysis module 13 exceed the average value of the data on the individual loss rates stored in the database. In this embodiment, it is calculated whether the individual loss rates calculated by the individual loss analysis module 13 exceed the average value of the individual loss rates of motors that meet the reference efficiency within the range of the standard deviation. If the value of the individual loss rate is known, not only can the efficiency of the motor be calculated, but also the design state of the motor can be grasped. Thus, when the individual loss rates calculated by the individual loss analysis module 13 exceed the average value within the range of the standard deviation, the motor meets the reference efficiency. In addition, when the individual loss rates calculated by the individual loss analysis module 13 are poor and the loss rate exceeds the average value by more than the standard deviation, the motor does not meet the reference efficiency. Moreover, when a specific individual loss rate is poor, diagnostic analysis of the motor can be performed.

[0030] For example, when the iron loss in the individual loss rate is high, it can be known that the core material and plate thickness are not good, and this needs to be explored. It can be expected that the efficiency will increase when the core material and plate thickness are improved. Moreover, when the mechanical losses such as friction and wind loss are high, it can be known that the bearings, fan design and manufacturing of the motor are poor, and the cooling is poor. Therefore, if the degree of each individual loss rate is known, the design state of the motor can be known. Thereby, the efficiency of the motor can be improved.

[0031] The output module 21 outputs the degree to which the efficiency calculated by the efficiency calculation module 15 and the individual loss rate calculated by the loss rate evaluation module 19 exceed the average value. Thus, the designer of the motor can know the problems of the motor and the efficiency improvement solutions from this.

[0032] The motor loss diagnosis method using the motor loss diagnosis system of this embodiment includes a data input step S11, an individual loss analysis step S13, an efficiency calculation step S15, a loss rate evaluation step S17, a data storage step S19, and an output step S21.

[0033] In the data input step S11, in order to measure the efficiency of the motor 1, the data input module 11 receives the input of operation data such as voltage, current, active power, temperature, torque, and speed of the operating motor 1 from the sensors attached to the motor 1.

[0034] In the individual loss analysis step S13, the individual loss analysis module 13 uses the operation data input from the data input module 11 to calculate the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the operating motor 1.

[0035] In the efficiency calculation step S15, the efficiency calculation module 15 uses the individual loss rates calculated in the individual loss analysis step to calculate the efficiency of the motor 1.

[0036] In the loss rate evaluation step S17, the database stored in the storage module 17 is compared with the individual loss rates calculated in the individual loss analysis step S13, and the degree to which the individual loss rates calculated in the individual loss analysis step S13 exceed the average value of the data stored in the database is calculated. That is, it is judged whether the degree to which the individual loss rates calculated in the individual loss analysis step S13 exceed the average value of the individual loss rates that meet the reference efficiency is within the standard deviation. When all the individual loss rates calculated in the individual loss analysis step S13 are within the standard deviation, it can be known that the motor meets the reference efficiency. If some of the individual loss rates exceed the standard deviation, it can be known that there is a problem with the design of the motor.

[0037] In the data storage step S19, when the efficiency of the motor 1 calculated in the efficiency calculation step S15 is above the reference efficiency, the individual loss rates calculated in the individual loss analysis step S13 are stored in the database of the storage module 17. That is, the data storage step S19 is used to update the data of the individual loss rates of the motors that meet the reference efficiency. Through the data storage step S19, the motor loss diagnosis system 10 can accumulate more data on individual loss rates.

[0038] In the output step S21, the output module 21 outputs the efficiency calculated in the efficiency calculation step S15 and the degree of excess calculated in the loss rate evaluation step S17. Figure 3 andFigure 4 This is an example output by output step S21. As Figure 3 and Figure 4 shown, the degree of each individual loss rate can be grasped. If the degree of each individual loss rate is grasped, the problems of the motor can be known. As Figure 3 shown, when the iron loss is high, that is, when the standard deviation from the average value is high, it can be known that there are problems with the material of the iron core and the thickness of the plate, and it needs to be explored. Moreover, as Figure 4 shown, when the mechanical losses such as friction and windage are high, it can be known that the bearing design is poor and the cooling is poor.

[0039] Therefore, according to this embodiment, not only can it be judged whether the efficiency of the motor meets the reference efficiency, but also the motor can be diagnosed through the individual loss analysis of the motor.

Claims

1. A method for diagnosing motor losses, characterized in that, comprising: A data input step of accepting the input of the operating data of the motor for measuring the efficiency of the motor, where the operating data includes the voltage, current, active power, temperature, torque, and speed of the motor; An individual loss analysis step of using the operating data to calculate the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor; An efficiency calculation step of using the individual loss rates calculated in the individual loss analysis step to calculate the efficiency of the motor; A loss rate evaluation step of calculating the degree to which the individual loss rates calculated in the individual loss analysis step exceed the average value of the data stored in a database storing the individual loss rate data of motors meeting the reference efficiency; A data storage step of storing the individual loss rates calculated in the individual loss analysis step in the database and updating the data of the individual loss rates of motors meeting the reference efficiency stored in the database when the efficiency calculated in the efficiency calculation step is above the reference efficiency; An output step of outputting the efficiency calculated in the efficiency calculation step and the degree of excess calculated in the loss rate evaluation step, wherein the output step outputs in a manner that enables knowing whether the degree of excess calculated in the loss rate evaluation step exceeds the standard deviation from the average value.

2. A motor loss diagnosis system, characterized in that, comprising: A data input module that accepts the input of the operating data of the motor for measuring the efficiency of the motor, where the operating data includes the voltage, current, active power, temperature, torque, and speed of the motor; An individual loss analysis module that uses the operating data to calculate the individual loss rates of the iron loss rate, mechanical loss rate, additional load loss rate, stator loss rate, and rotor loss rate of the motor; An efficiency calculation module that uses the individual loss rates calculated by the individual loss analysis module to calculate the efficiency of the motor; A storage module having a database that stores the data of the individual loss rates of motors meeting the reference efficiency; A loss rate evaluation module that calculates the degree to which the individual loss rates calculated by the individual loss analysis module exceed the average value of the data stored in the database; An output module that outputs the efficiency calculated by the efficiency calculation module and the degree of excess calculated by the loss rate evaluation module, wherein the output module outputs in a manner that enables knowing whether the degree of excess calculated by the loss rate evaluation module exceeds the standard deviation from the average value, and when the efficiency calculated by the efficiency calculation module is above the reference efficiency, the storage module stores the individual loss rates calculated by the individual loss analysis module in the database and updates the data of the individual loss rates of motors meeting the reference efficiency stored in the database.

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