KR101823922B1 - Motor startup system capable of active state diagnosis - Google Patents

Abstract

The present invention relates to a motor starting system capable of an active state diagnosis. More specifically, the present invention relates to a motor starting system capable of an active state diagnosis which analyzes and stores a harmonic wave of load current output according to a state of a motor, divides and analyzes an area of the harmonic wave according to a breakdown type and periodically analyzes increase/decrease of a breakdown harmonic wave, thereby diagnosing the breakdown as well as progress of the breakdown.

Description

[0001] The present invention relates to a motor startup system capable of diagnosing an active state,

[0001] The present invention relates to a motor starting system capable of diagnosing an active state, more particularly, to analyzing and storing a harmonic of a load current output according to a state of a motor, The present invention relates to a motor starter system capable of diagnosing not only a failure but also an active state diagnosis that can diagnose even the progress of a failure by analyzing the increase / decrease of a fault harmonic.

A motor (electric motor) is a device that converts electrical energy into mechanical energy by using the power that a current conductor receives in a magnetic field. It is used in various transportation facilities, automated production facilities, water intake and sewage treatment facilities. In order to control the efficient operation of the motor in the facility using the motor, a motor starting system is constructed as described in the following patent document. The motor starting system prevents the motor from burning due to an inrush current generated when the motor starts, Y- △ Protects the motor from inrush current through starting, reactor start, and inverter start. In addition, the motor starting system includes various sensors and communication equipment for monitoring the motor overload and failure status.

<Patent Literature>

Open No. 10-1993-0015279 (published on July 24, 1993) "Single-phase motor starting system"

However, in the conventional motor starting system, it is difficult to prevent the failure in advance, and in order to proactively diagnose faults, a costly and complicated diagnosis system must be constructed separately, which leads to a problem of low economical efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems,

An object of the present invention is to provide a motor starting system capable of real-time detection and data acquisition of an electric signal generated at the time of driving of a motor and performing fault detection and state diagnosis through data analysis after processing according to a fault type. have.

In addition, the present invention adds a FFT (Fast Fourier Transform) function to a power meter used in a general motor maneuvering unit, and computes it through a controller (Programmable Logic Controller) that performs motor start / It is an object of the present invention to provide a motor start system that enables economical active state diagnosis without adding expensive and complex diagnostic systems.

In order to achieve the above object, the present invention is implemented by the following embodiments.

According to an embodiment of the present invention, a motor start system according to the present invention includes a harmonic measurement module for sensing a load current flowing in accordance with operation of a motor and outputting a harmonic signal value, And diagnoses a fault and a condition of the motor.

According to another embodiment of the present invention, in the motor starter system according to the present invention, the fault diagnosis unit includes a state determiner for periodically collecting and storing harmonic signal values output from the harmonic measurement module in a predetermined normal operation state, And a fault alarm unit for analyzing the harmonic signal value output from the state determiner and outputting an alarm signal indicating that a fault is expected to occur within a predetermined period of time even though the current motor is not in a fault state.

According to another embodiment of the present invention, in the motor starter system according to the present invention, when the alarm signal indicating that a failure is expected to be generated is not output from the failure alarm unit, And outputting an alarm signal indicating that there is an abnormality in the motor state.

According to another embodiment of the present invention, in the motor starting system according to the present invention, the harmonic measurement module includes an FFT operation unit for sensing a load current and decomposing a fundamental wave and harmonics for each order through a Fourier transform (FFT) A harmonic classifying unit for classifying harmonics of each order disassembled by the FFT arithmetic unit according to a failure type of the motor, and a classifying signal value calculating unit for calculating and outputting harmonic signal values according to the harmonic classifications output from the harmonic classifying unit .

According to another embodiment of the present invention, in the motor starter system according to the present invention, the fault alarm unit compares the harmonic signal value output from the state determination unit with the harmonic signal value of the steady state of the predetermined motor, And a threshold value determiner for outputting a signal indicating that a failure occurs within a predetermined period of time when the variation detected by the variation detector is out of a preset threshold value.

According to another embodiment of the present invention, in the motor starting system according to the present invention, when the failure judging unit outputs the failure prediction signal, the failure warning unit confirms the harmonic classification associated with the failure prediction signal, And a warning signal output unit for outputting a failure type of the motor and a failure prediction signal to the user terminal when the failure type of the motor is output from the type determination unit.

According to another embodiment of the present invention, in the motor starter system according to the present invention, when the alarm signal indicating that the failure is expected to be generated is not output from the failure alarm unit, A slope detector for calculating a slope of a harmonic signal value by collecting a harmonic signal value of a period and confirming a change of a harmonic signal value for each unit period, and a slope detector for calculating a slope of the harmonic signal value when the slope detected by the slope detector exceeds a predetermined threshold, And outputting a signal indicating that the abnormal state is continuously increasing.

According to another embodiment of the present invention, in the motor starter system according to the present invention, when the signal indicating that the motor is in an abnormal state in which the fine damage continuously increases in the threshold comparator, A type determining unit for determining a type of an abnormal state of the motor by checking the harmonic classification associated with the motor; and an abnormality type of the motor when the abnormality type of the motor is outputted from the type discrimination unit, And an abnormal signal output unit for outputting a signal to the user terminal.

According to another embodiment of the present invention, in the motor starting system according to the present invention, the harmonic signal value is calculated as a distortion rate of harmonics classified by a harmonic classification, and the failure state diagnosis unit detects a failure signal output from the protection relay, Wherein the state determiner determines that the harmonic signal value output from the harmonic measurement module is in a state where the failure notification signal is not output by the failure detector during the predetermined normal operation state, Are periodically collected and stored.

According to another embodiment of the present invention, in the motor starter system according to the present invention, the preset normal operation state means a state in which the predetermined normal load or the inverter is operated on the basis of the normal inverter operation frequency, And the data is set with the data repeatedly tested in accordance with the data.

The present invention can obtain the following effects by the above-described embodiment, the constitution described below, the combination, and the use relationship.

The present invention has the effect of real-time detection and data acquisition of an electric signal generated at the time of driving of a motor, fault detection and condition diagnosis through processing analysis after sorting data according to a fault type.

In addition, the present invention adds a FFT (Fast Fourier Transform) function to a power meter used in a general motor maneuvering unit, and computes it through a controller (Programmable Logic Controller) that performs motor start / It is possible to economically perform an active condition diagnosis without adding expensive and complicated diagnosis system.

1 is a block diagram of a motor start system in accordance with an embodiment of the present invention;
FIG. 2 is a block diagram showing a detailed configuration of the harmonic measurement module of FIG. 1; FIG.
3 is a block diagram showing a detailed configuration of the failure diagnosis unit of FIG.
Fig. 4 is a block diagram showing the detailed configuration of the failure alarm unit of Fig. 3; Fig.
5 is a block diagram showing a detailed configuration of the abnormal state determiner in FIG.
6 is a reference diagram for explaining the tilt detecting section of Fig. 5;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a motor start system capable of diagnosing an active state according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Throughout the specification, when an element is referred to as "including" an element, it is understood that the element may include other elements as well as other elements, The terms "part," " module, "and the like denote a unit for processing at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

1 to 6, a motor starting system capable of performing an active state diagnosis according to an embodiment of the present invention will be described. The motor starting system includes a harmonic And a fault diagnosis unit 52 for diagnosing a failure and a condition of the motor by analyzing the harmonic signal values output from the harmonic measurement module 11. The fault diagnosis unit 52 includes a fault diagnosis unit 52, The conventional motor starting system includes a power meter 1, a protection relay 2, an electric circuit breaker 3, a sensor meter 4 and a controller 5. The controller 5 includes a power meter 1, And a motor start control unit 51 for controlling the safety relay 2, the electric circuit breaker 3 and the sensor meter 4. The present invention is characterized in that the harmonics measurement module 11 is added to the power meter 1 And the fault state diagnosis unit 52 is installed in the controller 5 by adding software to economically perform active state diagnosis without adding a complicated and expensive diagnosis system to the existing motor starting system. The electric power meter 1, the protection relay 2, the electric circuit breaker 3, the sensor meter 4 and the motor start control unit 51 of the present invention are used in a conventional motor starting system, do.

The harmonic measurement module 11 is configured to sense a load current flowing in accordance with the operation of the motor and output a harmonic signal value. The harmonic measurement module 11 includes an FFT calculation unit 111, a harmonic classification unit 112, a classification signal value calculation unit 113, . The load current flowing in accordance with the operation of the motor has a form of a periodic compound wave, not a sinusoidal wave, and the periodic compound wave is decomposed into a component having a fundamental wave component and an integer multiple thereof, , And the harmonic is changed when an electric or mechanical defect occurs in the motor. Therefore, the present invention senses the load current, outputs the harmonic signal value, and analyzes the harmonic signal value The motor failure and condition diagnosis are performed.

The FFT operation unit 111 senses the load current and decomposes the fundamental wave and harmonics of each order through FFT (Fast Fourier Transform).

The harmonic classification unit 112 categorizes harmonics of each order disassembled by the FFT operation unit 111 according to the failure type of the motor. (E. G., In the case of mechanical destruction defects), which varies greatly depending on the type of fault of the motor And the 3n-th harmonic in the case of a cable overheating fault), the harmonic classifying unit 112 categorizes the harmonics of each order according to the failure type of the motor. For example, the harmonic classification section 112 can be classified into 3n-order harmonics (3rd, 6th, 9th, ..., 45th, 48th harmonics), 2nd harmonic, 6n 1st harmonic,

과 같이 표시되게 되며, I₁은 기본파의 전류의 r.m.s 값이며, I_2n은 2n차 고조파의 전류의 r.m.s값이다. 본 발명은 고조파의 모든 성분에 대한 데이터를 컨트롤러(5)에 전송하는 것이 아니라, 각 차수별 고조파를 모터의 고장 유형별로 범주화하여 고조파 분류별로 합산된 데이터를 컨트롤러(5)에 전송하므로, 통신부하의 증가를 억제하고 컨트롤러(5)의 연산부하를 저감시킬 수 있게 된다.The signal-to-noise ratio calculator 113 calculates and outputs a harmonic signal value for each harmonic wave signal outputted from the harmonic wave signal classifier 112. For example, the harmonic signal value can be calculated by the distortion ratio of harmonics classified by classification, and when the classification of harmonics is 2n,

I ₁ is the rms value of the fundamental wave current, and I _2n is the rms value of the 2nth harmonic current. The present invention does not transmit data on all the harmonic components to the controller 5 but categorizes the harmonics for each order by the failure type of the motor and transmits the summed data for each harmonic classification to the controller 5, So that the calculation load of the controller 5 can be reduced.

The fault diagnosis unit 52 analyzes the harmonic signal value output from the harmonic measurement module 11 to diagnose the fault and the condition of the motor. The fault diagnosis unit 52 includes a fault detection unit 521, a state determination unit 522, An alarm unit 523, an abnormal state determination unit 524, and the like.

The failure detection unit 521 detects a failure signal output from the protection relay 2 and performs failure classification to output a failure notification signal. Since the protection relay 2 outputs a failure signal when a complete failure occurs in the motor and a plurality of relays that perform different functions are used in the protection relay 2, It is possible to output a fault notification signal by classifying faults through analysis.

The state determination unit 522 periodically collects and stores the harmonic signal value output from the harmonic measurement module 11 in a state where the failure detection signal is not output by the failure detection unit 521 during a predetermined normal operation state (Not shown). The storage unit stores the set harmonic signal value, the periodically collected output harmonic signal value, the threshold value used by the threshold value determination unit 523b, and the threshold value used by the threshold value comparison unit 524b. In the motor operation state in which the load fluctuation is severe or the variable speed is generated by the inverter, the content of the harmonics varies and the determination of the fault alarm unit 523 and the abnormality state determiner 524 may be inaccurate. The harmonics signal value is collected and used for the analysis in the set normal operation state (for example, the predetermined normal load or the operation state based on the normal inverter operation frequency), so that the failure alarm unit 523 and the abnormality state determination unit 524 Judgment error can be suppressed.

The failure alarm unit 523 analyzes the harmonic signal value output from the state determination unit 522 and outputs an alarm signal indicating that a failure is expected to occur within a predetermined period of time even though the current motor is not in a failure state. A threshold value determination unit 523b, a type determination unit 523c, a warning signal output unit 523d, and the like.

The variation detector 523a receives the harmonic signal value (hereinafter, referred to as an output harmonic signal value) output from the state determiner 522 and the harmonic signal value of the predetermined state of the motor Quot; signal value &quot;) to detect a change.

The threshold value determination unit 523b outputs a signal indicating that a failure occurs within a predetermined period (hereinafter referred to as a failure prediction signal) when the variation detected by the variation detection unit 523a is out of a preset threshold value. The threshold value is a numerical value indicating that a failure occurs after a predetermined period of time in a steady state. For example, the threshold value may be set with data repeatedly tested according to a specific situation. Specifically, when the set harmonic signal value is set at 10% and the threshold value at which the failure occurs within 15 days is set to 3%, and the output harmonic signal value is 14%, the change output from the change detector 523a The threshold value determination unit 523b outputs a signal indicating that a failure occurs within 15 days since the threshold value is 4% and exceeds the threshold value 3%.

When the failure predicting unit 523c outputs the failure prediction signal, the type determining unit 523c determines the failure type of the motor by checking the harmonic classification associated with the failure prediction signal. Harmonics of each order are categorized according to the fault type of the motor and harmonic classification is performed and harmonic signal values are outputted according to the harmonic classification. Therefore, when the failure prediction signal is outputted, the harmonic classification having the output harmonic signal value used for the determination is confirmed, It is possible to determine the failure type of the failure.

The warning signal output unit 523d outputs a failure type of the motor and a failure prediction signal to the user terminal (not shown) when the type of the failure of the motor is outputted by the type determination unit 523c.

When the alarm signal indicating that a failure is expected to be generated is not output from the failure alarm unit 523, the abnormal state determination unit 524 determines a transition of the harmonic signal value of the predetermined period output from the state determination unit 522 And includes an inclination detector 524a, a threshold comparator 524b, a type discriminator 524c, an abnormal signal output unit 524d, and the like, and outputs an alarm signal indicating that the motor state is abnormal.

When the alarm signal indicating that a failure is expected to be generated is not output from the failure alarm unit 523, the inclination detector 524a collects the harmonic signal values of the predetermined period output from the state determiner 522, The slope of the harmonic signal value is calculated by confirming the change of the harmonic signal value. When the harmonic signal value increases or decreases according to the unit period, the slope can be calculated. If the motor is operating normally because it is not a complete failure, but the fine damage of the motor continuously increases, the harmonic signal value is continuously It is possible to confirm that the motor damage does not occur within the present or the earlier time but the micro damage of the motor is continuously increased. FIG. 6 is a diagram illustrating an example in which the unit period is one month and the harmonic signal value increases by a unit period to have a plus slope (H).

The threshold comparator 524b outputs a signal indicating that the motor is in an abnormal state where the micro damage continuously increases when the slope detected by the slope detector 524a exceeds a preset threshold value. The threshold value is a numerical value indicating that the micro damage continuously increases in a steady state of the motor. For example, the threshold value may be set with data repeatedly tested according to a specific situation.

When a signal indicating that the motor is continuously in an abnormal state in which the micro-damage continuously increases is output from the threshold value comparing unit 524b, the type determining unit 524c checks the harmonic classification associated with the signal to determine the abnormal state type of the motor . Harmonics of each order are categorized by motor fault type and harmonic classification is performed and harmonic signal value is outputted according to harmonic classification. When a signal indicating abnormal state is outputted, confirmation of harmonic classification having output harmonic signal value used for judgment So that it is possible to determine the abnormal state type of the motor.

When the type of the abnormality of the motor is outputted from the type discrimination unit 524c, the abnormality signal output unit 524d outputs a signal indicating that the abnormality type of the motor and the abnormality state in which the motor continuously increases the fine damage, (Not shown).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Should be interpreted as falling within the scope of.

1: Power meter 2: Protection relay 3: Electric breaker
4: Sensor meter 5: Controller 11: Harmonic measurement module
51: motor start control unit 52: fault diagnosis unit 111: FFT operation unit
112: Harmonic wave classifying section 113: Classified signal value calculating section 521:
522: state determination unit 523: failure alarm unit 524: abnormal state determination unit
523a: change detection part 523b: threshold value determination part 523c: type determination part
523d: warning signal output unit 524a: tilt detection unit 524b: threshold comparison unit
524c: type discrimination unit 524d: abnormal signal output unit

Claims (10)

1. A motor starting system including a power meter and a controller for controlling the power meter,
A harmonic measurement module provided additionally to the power meter for sensing a load current flowing in accordance with the operation of the motor to output a harmonic signal value; and a harmonic measurement module installed in the controller to add a harmonic signal value output from the harmonic measurement module And diagnoses a fault and a condition of the motor,
The fault diagnosis unit periodically collects and stores a harmonic signal value output from the harmonic measurement module in a predetermined normal operation state. The fault diagnosis unit analyzes the harmonic signal value output from the state determination unit, A failure alarm unit for outputting an alarm signal indicating that a failure is expected to occur within a predetermined period of time even though the failure alarm unit is not in operation; And outputting an alarm signal indicating that there is an abnormality in the motor state,
The predetermined normal operation state means a state in which the inverter is operated based on a predetermined constant load or a constant inverter operation frequency,
The harmonic measurement module includes an FFT calculator for sensing a load current and decomposing fundamental waves and harmonics of respective orders through a Fourier transform, and a controller for classifying the harmonics of each order disassembled by the FFT calculator, A harmonic classification section for causing a specific high frequency classification matched to a specific failure type of the motor to include a plurality of harmonics for each order; and a harmonic classification section for, for each harmonic classification including a plurality of harmonics for each order, And outputting the classified signal value,
The harmonic signal value is calculated as a distortion ratio of harmonics according to harmonic classification,
The abnormal state determiner collects harmonic signal values of a predetermined period output from the state determiner when an alarm signal indicating that a failure is expected to be generated is not output from the fault alarm unit, and checks the change of the harmonic signal value for each unit period A threshold comparator for outputting a signal indicating that the motor is in an abnormal state in which the micro damage continuously increases when the slope detected by the slope detector exceeds a preset threshold value; A type discrimination unit for discriminating an abnormal state type of the motor by confirming harmonic classification associated with the signal when a signal indicating that the motor is in an abnormal state in which the micro damage continuously increases in the comparison unit is outputted; If the abnormal state type of the motor is output, Three to damage includes continually increasing the signal that the abnormal state at least an output signal to be output to the user terminal for the motor start-up system according to claim. delete delete delete The apparatus of claim 1, wherein the failure alarming unit
A change detector for comparing the harmonic signal value output from the state determiner with a harmonic signal value of a predetermined state of the motor to detect a change; and a controller for, when a change amount detected by the change detector is out of a predetermined threshold, And outputting a signal indicating that a failure occurs within a predetermined period of time. 6. The apparatus of claim 5, wherein the failure alarming unit
A type determination unit for determining a fault type of the motor by confirming a harmonic classification associated with the failure prediction signal when the failure determination unit outputs the failure prediction signal; Further comprising a warning signal output unit for outputting a fault type of the motor and a failure prediction signal to the user terminal. delete delete The method according to claim 1,
Wherein the fault diagnosis unit further includes a fault detection unit for detecting a fault signal output from the protection relay and performing fault classification to output a fault notification signal. delete

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