KR102621855B1 - Apparatus for detecting motor fault - Google Patents

Abstract

This specification relates to a motor failure detection device. More specifically, the back electromotive force is measured by detecting the voltage at both ends of a pair of measurement target teeth. It relates to a motor failure detection device that measures and detects failure.

Description

Motor failure detection device{APPARATUS FOR DETECTING MOTOR FAULT}

This specification relates to a motor failure detection device, and more specifically, to a motor failure detection device that detects a failure by measuring the back electromotive force induced in the teeth constituting each phase of the motor.

The technology behind the present invention is a technology for detecting a motor failure, and specifically relates to a technology for detecting a motor failure by measuring the back electromotive force induced in the teeth of the motor.

Figure 1 is a diagram showing a 12-pole, 9-slot PM motor, which is a general rotationally symmetrical motor.

Referring to FIG. 1, when the rotor hub 110 and the permanent magnet 120 rotate, the air gap magnetic flux density is determined by interaction with the stator core 130 and a back electromotive force is induced in the winding 140. For reference, the air gap refers to the gap between the permanent magnet 120 and the stator core 130.

Figure 2 is a diagram showing a commonly used three-phase Y-winding.

As shown in Figure 2, in a typical centralized winding motor, the u, v, and w phases exist in that order, and the windings 10 constituting each phase (u, v, w) are mainly connected in series. Therefore, the back electromotive force induced in each phase is expressed as the sum of the back electromotive force induced in the windings 10 constituting each phase.

When a failure occurs in the bearing of a motor, vibration of the rotating motor occurs, causing fluctuations in air gap magnetic flux density. At this time, a change occurs in the waveform of the back electromotive force induced in each tooth. However, in a motor with a rotationally symmetrical structure, changes in air gap magnetic flux density cannot be detected.

As a conventional motor failure detection method, "Republic of Korea Patent 10-152119B1" measures the back electromotive force induced in at least one of the teeth constituting each phase of the motor or the teeth constituting one of each phase of the motor. We proposed a method to detect motor failure by measuring back electromotive force, which measures the back electromotive force induced in each. Specifically, we proposed a method of detecting the dynamic eccentricity of the motor by determining the magnitude of the ±1 component other than the fundamental frequency through frequency analysis of the measured back electromotive force, and a method of detecting the static eccentricity of the motor by determining the magnitude of the fundamental frequency. suggested. This proposed method required installing additional windings in the motor, which indicated a structural limitation of the prior art.

It is difficult to install additional windings in commonly used motors because the space for installing additional windings is limited. The back electromotive force induced in the coil tends to increase in proportion to the number of turns of the winding, and when the number of turns of the winding is small, the magnitude of the back electromotive force generated is also detected as small. Therefore, detecting back electromotive force using a small number of windings may not be sufficient to detect motor failure.

As a result, the conventional technology has a limitation in that it is inevitably equipped with a limited configuration for fault detection due to the internal structural limitations of the motor. In addition, due to these structural limitations, it is not possible to easily measure back electromotive force to a level where fault detection is possible, so there is a limitation that measurement of back electromotive force and fault detection cannot be easily performed. These limitations also result in motor failure. There were problems that made it difficult to configure and design the detection itself.

KR 10-1521119 B1

Therefore, this specification aims to solve the limitations of the prior art, and aims to provide a motor failure detection device that can measure the back electromotive force induced in the teeth constituting each phase of the motor using existing windings without additional windings. do.

In addition, this specification seeks to provide a motor failure detection device that can measure back electromotive force by detecting the voltage of the tooth at a level that allows measurement of back electromotive force without additional winding.

The motor failure detection device disclosed in this specification for solving the problems described above is a means of detecting and measuring the back electromotive force of at least one pair of teeth among the teeth constituting each phase of the motor by detecting the voltage at both ends of the teeth without additional winding. Do it as

In other words, unlike the conventional technology of connecting an additional winding to the measurement target and detecting the voltage through the additional winding, the voltage across both ends of the measurement target is detected at the point where it passes from the measurement target to the adjacent value. It is characterized by measuring the back electromotive force induced in.

Alternatively, the method is characterized in that the voltage across both ends of the measurement target tooth is detected between the measurement target tooth and an adjacent tooth, and the back electromotive force induced in the measurement target tooth is measured.

The motor failure detection device disclosed in the present specification, which features the technical idea as described above, includes a back electromotive force measuring unit that measures the back electromotive force induced in at least one pair of teeth among the plurality of teeth constituting each phase of the motor, and the measured It includes a comparative analysis unit that compares and analyzes back electromotive force and a failure detection unit that detects a failure of the motor based on the results of the comparative analysis, wherein the back electromotive force measurement unit detects the voltage at both ends of each pair of measurement target values to determine the counter electromotive force. When measuring, the voltage is detected at the point where the measurement target value passes to an adjacent value.

In one embodiment, the back electromotive force measurement unit may include a voltage detection unit that detects a voltage at both ends of the measurement target tooth between the measurement target tooth and the adjacent tooth.

In one embodiment, the voltage detector may be connected to a winding of the measurement target between the measurement target and the adjacent tooth to directly detect the voltage at both ends of the measurement target.

In one embodiment, the back electromotive force measuring unit may measure the back electromotive force induced in each of a pair of teeth constituting the same phase among each phase of the motor.

In one embodiment, the back electromotive force measuring unit may measure the back electromotive force induced in each of a pair of teeth disposed in positions facing each other.

In one embodiment, the comparative analysis unit may compare and analyze voltage waveforms at both ends of each of the measurement target values.

In one embodiment, the comparison and analysis unit may calculate a difference between voltages at both ends of each of the measurement target values, and compare and analyze the measured back electromotive force based on the calculated result.

In one embodiment, the comparative analysis unit may calculate a difference between the voltages at both ends of each of the measurement target values so that fundamental wave components of the voltages at both ends of each measurement target value cancel each other out.

In one embodiment, the calculated result may be such that the fundamental wave components of the voltage at both ends of each of the measurement target values cancel each other out, and any component other than the fundamental wave component may be added and increased.

The motor failure detection device disclosed in this specification detects and measures the back electromotive force of at least one pair of teeth among the teeth constituting each phase of the motor by detecting the voltage at both ends of the teeth without additional winding, thereby causing the failure of the motor without a separate configuration for measuring the back electromotive force. This has the effect of being able to detect.

As a result, the motor failure detection device disclosed in this specification can not only improve structural limitations and limited design problems inside the motor, but also simplify the design for failure detection, thereby reducing costs. There is a possible effect.

In addition, the motor failure detection device disclosed in this specification detects the voltage at both ends of a pair of teeth without an additional winding, calculates the difference between the two voltages, and measures the back electromotive force, thereby measuring the back electromotive force of a measurable size without an additional winding. This has the effect of making it possible to simply measure back electromotive force and detect motor failure.

1 is a structural diagram showing the structure of a general rotationally symmetrical PM motor.
Figure 2 is a structural diagram showing a three-phase Y-winding structure used in a general rotationally symmetrical PM motor.
Figure 3 is a configuration diagram showing the configuration of the motor failure detection device disclosed in this specification.
Figure 4 is a structural diagram showing the structure of a motor to which the motor failure detection device disclosed in this specification is applied.
Figure 5 is an exemplary diagram showing an example of back electromotive force measurement according to an embodiment of the motor failure detection device disclosed in this specification.
FIG. 6 is an exemplary diagram showing an example of a voltage waveform according to an example measurement as shown in FIG. 5.
FIG. 7 is an exemplary diagram showing an example waveform of a measurement result according to an example measurement as shown in FIG. 5.
Figure 8 is an example diagram showing a motor when stator eccentricity occurs due to motor failure.
Figure 9 is an example diagram showing a motor when rotor eccentricity occurs due to motor failure.

The motor failure detection device disclosed in this specification can be applied and implemented as a device for detecting a failure of a PM motor, and in particular, measures the back electromotive force induced in the teeth constituting each phase of the motor to measure the stator/rotor eccentricity of the motor, etc. It can be usefully applied to and implemented in devices that detect failures by judging.

It should be noted that the technical terms used in this specification are only used to describe specific embodiments and are not intended to limit the spirit of the technology disclosed in this specification. In addition, the technical terms used in this specification, unless specifically defined in a different way in this specification, should be interpreted as meanings generally understood by those skilled in the art in the field to which the technology disclosed in this specification belongs. It should not be interpreted in a very comprehensive sense or in an excessively reduced sense. Additionally, if the technical terms used in this specification are incorrect technical terms that do not accurately express the idea of the technology disclosed in this specification, they should be replaced with technical terms that can be correctly understood by those skilled in the art. Additionally, general terms used in this specification should be interpreted as defined in the dictionary or according to the context, and should not be interpreted in an excessively reduced sense.

Additionally, as used herein, singular expressions include plural expressions, unless the context clearly dictates otherwise. In this specification, terms such as “consists of” or “comprises” should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or steps may include It may not be included, or it should be interpreted as including additional components or steps.

Additionally, when describing the technology disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the technology disclosed in this specification, the detailed description will be omitted. In addition, it should be noted that the attached drawings are only intended to facilitate easy understanding of the spirit of the technology disclosed in this specification, and should not be construed as limiting the spirit of the technology by the attached drawings.

Hereinafter, an embodiment of the motor failure detection device disclosed in this specification will be described with reference to FIGS. 3 to 9.

Figure 3 is a configuration diagram showing the configuration of the motor failure detection device disclosed in this specification.

Figure 4 is a structural diagram showing the structure of a motor to which the motor failure detection device disclosed in this specification is applied.

Figure 5 is an exemplary diagram showing an example of back electromotive force measurement according to an embodiment of the motor failure detection device disclosed in this specification.

FIG. 6 is an exemplary diagram showing an example of a voltage waveform according to an example measurement as shown in FIG. 5.

FIG. 7 is an exemplary diagram showing an example waveform of a measurement result according to the measurement example shown in FIG. 5.

Figure 8 is an example diagram showing a motor when stator eccentricity occurs due to motor failure.

Figure 9 is an example diagram showing a motor when rotor eccentricity occurs due to motor failure.

The motor failure detection device (hereinafter referred to as a detection device) disclosed in this specification may be a device that detects a failure of a PM (Permanent Magnet) motor.

The detection device may be implemented in a module form.

The detection device may be built into the motor or a control device that controls the motor, and may detect a failure of the motor.

As shown in FIG. 3, the detection device 200 includes a back electromotive force measurement unit 210, a comparative analysis unit 220, and a failure detection unit 230.

The detection device 200 includes the back electromotive force measurement unit 210, the comparative analysis unit 220, and the failure detection unit 230, and measures the back electromotive force induced in the teeth constituting each phase of the motor to determine if the malfunction occurs. Detect.

The detection device 200 can detect a failure of a motor that has a geometrically even-numbered rotationally symmetrical structure.

The detection device 200 can detect a malfunction by measuring the back electromotive force induced in the teeth of a motor structured as shown in FIG. 4.

The motor shown in FIG. 4 represents a motor with an 8-pole, 12-slot (teeth) structure, and the numbers 1 to 12 represent each of the teeth constituting each phase of the motor.

The detection device 200 may preferably be applied to a motor having an 8-pole, 12-slot (teeth) structure as shown in FIG. 4.

Hereinafter, an embodiment of the detection device 200 will be described focusing on an example of a motor structured as shown in FIG. 4.

The back electromotive force measurement unit 210 measures the back electromotive force induced in at least one pair of teeth among a plurality of teeth constituting each phase of the motor.

That is, the back electromotive force measuring unit 210 may measure the counter electromotive force induced in at least two teeth.

For example, if it is a three-phase motor and there are four values constituting each phase (u, v, w) of the motor, the back electromotive force measuring unit 210 measures one pair (two) of the four values constituting the u phase. ), or the back electromotive force induced in any one pair (two) of the four teeth constituting the v phase, or any one pair (two) of the four teeth constituting the w phase can be measured.

The comparison and analysis unit 220 compares and analyzes the measured back electromotive force.

The comparison and analysis unit 220 may compare and analyze the waveform and size of the back electromotive force of each measurement target value measured by the back electromotive force measurement unit 210.

The failure detection unit 230 detects a failure of the motor based on the comparative analysis results.

The failure detection unit 230 may detect a failure of the motor based on the comparative analysis result of the back electromotive force compared and analyzed by the comparison analysis unit 220.

The detection device 200 includes the back electromotive force measuring unit 210, the comparative analysis unit 220, and the failure detection unit 230, and the counter electromotive force measuring unit 210 includes each pair of measurement target values. The back electromotive force is measured by detecting the voltage at both ends of , and the voltage is detected at the point where the measurement target value passes to the adjacent value.

That is, the back electromotive force measurement unit 210 may detect the voltage across the measurement target tooth between both ends of the measurement target tooth and an adjacent tooth.

The back electromotive force measurement unit 210 may include a voltage detection unit 211 that detects the voltage at both ends of the measurement target tooth between the measurement target tooth and the adjacent tooth.

The voltage detection unit 211 is connected to a winding of the measurement target between the measurement target and the adjacent tooth, and can directly detect the voltage at both ends of the measurement target.

That is, the back electromotive force measurement unit 210 will directly detect the voltage across the measurement target tooth between the measurement target tooth and the adjacent tooth through the voltage detection unit 211 connected to the winding of the measurement target tooth. You can.

The voltage detection unit 211 may include a voltage sensor connected to a winding of the measurement target between the measurement target and the adjacent tooth.

The voltage detection unit 211 may be configured to scope the voltage of the winding of the measurement target between the measurement target and the adjacent tooth.

In this case, the voltage detection unit 211 may refer to a probe that is connected to each winding between the measurement target value and the in-conductor sum value and scopes the voltage at both ends of the measurement target value. The results scoped by the voltage detection unit 211 may be transmitted to the back electromotive force measurement unit 210 so that the back electromotive force measurement unit 210 may detect the voltage based on the scoped results.

That is, the voltage detection unit 211 may include a voltage sensor that senses the voltage of the winding of the measurement target, or may be configured to scope, and the back electromotive force measurement unit 210 may detect the voltage on the measurement target. Through the voltage detection unit 211 configured to detect the voltage of the measurement target tooth, the voltage across both ends of the measurement target tooth can be directly detected.

The voltage detection unit 211 may be a probe that is preferably connected to each winding between the measurement target value and the in-conductor sum value and scopes the voltage at both ends of the measurement target value.

An example of how the back electromotive force measurement unit 210 detects the voltage across the measurement target may be as shown in FIG. 5 .

As shown in FIG. 5, when the 1st value (TOOTH 1) and the 7th value (TOOTH 7) correspond to the measurement target values, the voltage detector 211 detects one winding of the 1st value (TOOTH 1) and , is connected to the winding between the 1st value (TOOTH 1) and the 4th value (TOOTH 4) adjacent to the 1st value (TOOTH 1) to detect the voltage (V1) across both ends of the 1st value (TOOTH 1), and the 7 It is connected to the winding between the bunch (TOOTH 7) and the adjacent number 10 (TOOTH 10), and the winding between the number 7 (TOOTH 7) and the adjacent number 4 (TOOTH 4), so that the voltage across both ends of the number 7 (TOOTH 7) (V7) may be detected.

The back electromotive force measuring unit 210 may also measure the back electromotive force induced in each of a pair of teeth constituting the same phase among each phase of the motor.

For example, as shown in FIG. 5, the back electromotive force induced in each of the two teeth constituting the u phase, the two teeth constituting the v phase, or the two teeth constituting the w phase among the three phases of the motor is It can be measured.

The back electromotive force measurement unit 210 measures the back electromotive force induced in each pair of teeth constituting the same phase among each phase of the motor, and can measure the back electromotive force in at least one phase.

The back electromotive force measuring unit 210 may also measure the back electromotive force induced in each of a pair of teeth disposed at positions facing each other.

For example, as shown in Figure 4, the dimensions of the motor are 1st - 7th, 2nd - 8th, 3rd - 9th, 4th - 10th, 5th - 11th, and 6th - When the 12th tooth is placed in a position facing each other, the back electromotive force induced in each tooth of any one of the pairs listed above can be measured. As an example of this, as shown in FIG. 5, the 1 The voltage across the bunch and the 7th bunch can be detected.

The voltage detection results at both ends of each of the measurement target teeth (No. 1 to No. 7) measured by the back electromotive force measuring unit 210 show that, due to the geometric structure of the motor as shown in FIG. 4, the fundamental wave component has a size and The phases are the same, and the 3rd and 5th harmonic components may have the same size but different phases.

More specifically, in the case of a motor with a rotational symmetry structure corresponding to an even multiple, such as an 8-pole 12-slot motor, the teeth constituting the same phase face each other. If the rotor eccentricity or stator eccentricity of the motor exists, the above Due to rotor eccentricity, the fundamental frequency component of the back electromotive force induced in the two teeth facing each other is generated with the same magnitude and phase, but the ±1 component of the fundamental frequency can be generated with the same magnitude and opposite phase.

In other words, as a result of measuring the back electromotive force induced in each of the measurement target values, if the fundamental frequency component has the same magnitude and phase, but the ±1 component of the fundamental frequency has the same magnitude and the phase is opposite to each other, the rotor eccentricity or It may be determined that a failure has occurred in the motor due to the presence of stator eccentricity.

The voltage detection results at both ends of each of the measurement target values (No. 1 to No. 7) measured by the back electromotive force measurement unit 210 may be as shown in FIG. 6 .

As shown in FIG. 6, the voltage detected at both ends of each of the 1st and 7th values has the same size and phase as the fundamental wave component, and the 3rd and 5th harmonic components have the same size but different phases. It can happen.

The voltage detection results at both ends of each of the measurement target values measured by the back electromotive force measurement unit 210 may be transmitted to the comparison analysis unit 220 for comparative analysis.

The comparison and analysis unit 220 may compare and analyze voltage waveforms at both ends of each measurement target value.

The comparison and analysis unit 220 compares and analyzes the voltage waveforms at both ends of each of the measurement target values, and compares and analyzes the magnitude and phase of the fundamental wave and harmonic components other than the fundamental wave of the back electromotive force induced in each of the measurement target values. You can.

The comparison and analysis unit 220 may calculate the difference between the voltages at both ends of each of the measurement target values, and compare and analyze the measured back electromotive force based on the calculated result.

For example, the difference (V1 - V7) between the 1st value voltage (V1) and the 7th value voltage (V7) can be calculated, and the measured back electromotive force can be compared and analyzed based on the calculated result.

The comparison and analysis unit 220 may calculate the difference between the voltages at both ends of each of the measurement targets so that the fundamental wave components of the voltages at both ends of each of the measurement targets cancel each other.

Here, in the calculated result, the fundamental wave components of the voltage at both ends of each of the measurement target values cancel each other out, and any component other than the fundamental wave component may be added and increased.

That is, when a malfunction occurs in the motor and eccentricity of the rotor or stator occurs, the back electromotive force induced in each of the measurement targets has the same fundamental wave component, and components other than the fundamental wave component are generated in different phases, so that the measurement When calculating the difference between the voltages at both ends of each target value, the fundamental wave components cancel each other out, and any one component other than the fundamental wave component can be added and increased.

Through this, a calculation result in which any component other than the fundamental wave component is increased is obtained, and the measured back electromotive force can be measured and comparatively analyzed based on the calculation result.

An example of the result calculated by the comparative analysis unit 220 may be as shown in FIG. 7 .

As shown in FIG. 7, the voltage detected at both ends of the first and seventh values has the same magnitude and phase as the fundamental wave component, and the 3rd and 5th harmonic components have the same size but different phases. Well, when calculating the difference between the two voltages, the fundamental wave component is canceled out and disappears, and the 3rd and 5th harmonic components can be doubled in size because they are the same size and opposite in phase.

The comparison and analysis unit 220 may perform Fourier Transform for comparative analysis of the measured back electromotive force on the calculation result.

The comparison and analysis unit 220 may perform Fourier transformation on the calculation result to compare and analyze the back electromotive force induced in each of the measurement target values.

Additionally, when the waveforms of the measured back electromotive force appear as sinusoids with different sizes, the comparative analysis unit 220 performs a relative comparison of the absolute magnitude of the measured back electromotive force through comparison of the magnitudes of the sinusoids, and compares the relative magnitude of the measured back electromotive force between the measured counter electromotive forces. You can also analyze the difference values.

Meanwhile, when dynamic eccentricity occurs due to a failure of the motor, the comparative analysis unit 220 converts the waveform of the back electromotive force induced to each measurement object into a frequency in the time domain to detect the dynamic eccentricity. The process of converting to a frequency domain can also be performed.

To this end, the comparative analysis unit 220 may perform Fourier transform on the waveform of the back electromotive force induced to each of the two measurement target values.

That is, when dynamic eccentricity occurs due to a failure of the motor, the comparative analysis unit 220 performs Fourier transformation on the waveform of the two-level counter electromotive force to extract the basic component and additional component (X ± 1) of the frequency. The difference between the back electromotive force of each value can also be analyzed by comparing the sizes of the basic component and the additional component.

The results compared and analyzed by the comparison and analysis unit 220 may be transmitted to the failure detection unit 230 and serve as the basis for failure detection.

The failure detection unit 230 may detect a failure of the motor based on the comparative analysis result of the back electromotive force compared and analyzed by the comparison analysis unit 220.

As an example, the failure detection unit 230 may detect the position and amount of eccentricity where the static eccentricity occurs based on the difference value between the back electromotive force through comparison of the magnitude of the sinusoidal wave.

In other words, if a difference occurs according to the size comparison of the sinusoids, the failure detection unit 230 determines that static eccentricity has occurred in the motor, and can detect the location and amount of eccentricity where the static eccentricity occurs.

In addition, the failure detection unit 230 may detect the position and amount of eccentricity where the dynamic eccentricity occurs based on the difference value between the back electromotive force through comparison of the frequency components of the two values of back electromotive force.

In other words, the failure detection unit 230 determines that dynamic eccentricity has occurred in the motor if an additional component (X ± 1) is included in addition to the basic component (X) among the frequency components of the two-level back electromotive force, and The location and amount of eccentricity where this occurs can be detected.

Hereinafter, it will be described in detail what results the process of detecting a motor failure through the detection device 200 brings and how the results are calculated.

In an ideal case where there is no malfunction in the motor, the back electromotive force induced in each gear can be expressed as [Equation 1] as follows.

[Equation 1]

Here, e represents the back electromotive force of each tooth, A represents the magnitude of the back electromotive force calculated by multiplying the number of turns of each tooth and the back electromotive force coefficient, and B represents the magnitude of the back electromotive force at the kth frequency. And, ακ represents the phase of the back electromotive force, and l represents the number of teeth.

Additionally, the back electromotive force induced in each phase can be expressed as the sum of the back electromotive force of each value constituting one phase, as shown in Equation 2 below.

[Equation 2]

Here, eu, ev, and ew represent the back electromotive force of each tooth on u, v, and w, respectively, and l represents the number of teeth.

In an ideal case where there is no fault in the motor, the back electromotive force of each phase appears as the same waveform with a phase difference of 120 degrees.

Figure 8 is a diagram showing a motor when stator eccentricity occurs due to motor failure.

As shown in FIG. 8, when stator eccentricity occurs due to a motor failure, the back electromotive force induced in each gear of the motor can be expressed as follows [Equation 3].

[Equation 3]

Here, e represents the back electromotive force of each tooth, A represents the magnitude of the back electromotive force calculated by multiplying the number of turns of each tooth and the back electromotive force coefficient, and B represents the magnitude of the back electromotive force at the kth frequency. And, ακ represents the phase of the back electromotive force, and l represents the number of teeth. In addition, ε represents the vector (distance) deviating from the original center of the stator, g represents the gap (air gap) in the ideal case without failure, and θ represents the angle deviating from the original center of the stator.

For reference, ε, g, and θ are fixed values.

When stator eccentricity occurs due to a failure of the motor, the size of the air gap in the direction of eccentricity decreases and the size of the back electromotive force relatively increases, and in the direction opposite to the eccentricity, the size of the air gap increases and the size of the back electromotive force relatively increases. It decreases. However, when calculating the sum of the back electromotive force constituting each phase, the back electromotive force fluctuations of each phase cancel each other out.

When stator eccentricity occurs due to a failure of the motor, when the back electromotive force at each point is detected, a change in the back electromotive force appears due to a malfunction of the motor. However, when stator eccentricity occurs due to a malfunction of the motor, detecting the back electromotive force of each phase prevents the change in back electromotive force from occurring due to a malfunction of the motor. Therefore, a motor failure can be detected only when the back electromotive force of each tooth is detected.

Figure 9 is a diagram showing a motor when rotor eccentricity occurs due to motor failure.

As shown in FIG. 9, when rotor eccentricity occurs due to a failure of the motor, the back electromotive force induced in each gear of the motor can be expressed as follows [Equation 4].

[Equation 4]

Here, e represents the back electromotive force of each tooth, A represents the magnitude of the back electromotive force calculated by multiplying the number of turns of each tooth and the back electromotive force coefficient, and B represents the magnitude of the back electromotive force at the kth frequency. And, ακ represents the phase of the back electromotive force, and m represents the number of teeth. In addition, ε represents the vector (distance) deviating from the original center of the rotor, g represents the gap (air gap) in the ideal case without failure, and wt represents the angular velocity deviating from the original center of the rotor.

For reference, ε and g are fixed values, and wt is a value that changes depending on t (time).

When rotor eccentricity occurs due to a failure of the motor, the size of the gap facing each other repeatedly increases and decreases at the same rate as the motor rotation frequency. Therefore, the magnitude of the back electromotive force induced in one tooth appears in the same form as the eddy phenomenon occurring in the sinusoidal wave. However, when the counter electromotive force of the elements that make up one phase are combined, this effect is also canceled out and disappears.

When rotor eccentricity occurs due to a failure of the motor, when the back electromotive force at each point is detected, a change in the back electromotive force appears due to the failure of the motor. However, when rotor eccentricity occurs due to a failure of the motor, detecting the back electromotive force of each phase prevents the change in back electromotive force from occurring due to a failure of the motor. Therefore, a failure of the motor can be detected only when the back electromotive force of each tooth is detected.

In this way, when a failure occurs in the motor, the back electromotive force induced in each tooth appears differently. Therefore, in order to detect a failure of the motor, the back electromotive force of each tooth can be detected to determine the change. In addition, in order to detect a failure of the motor, the back electromotive force waveforms of two or three or more of the values of the entire motor are required.

That is, the detection device 200 detects a waveform of back electromotive force induced in at least one pair of teeth among a plurality of teeth constituting each phase of the motor, and detects a failure of the motor through relative comparison analysis between waveforms. It can be done.

When stator eccentricity occurs due to a failure of the motor, the back electromotive force waveform generated at each tooth appears as a sinusoidal wave with different sizes. In this case, the detection device 200 can determine the position and amount of stator eccentricity where stator eccentricity occurs through relative comparison of the absolute magnitude of the back electromotive force.

When rotor eccentricity occurs due to a failure of the motor, the back electromotive force waveform generated at each tooth appears in a form that includes peripheral components in addition to the basic component. In this case, the detection device 200 can check the location and amount of rotor eccentricity where rotor eccentricity occurs by relative comparison of the sizes of peripheral components in addition to the basic component.

Embodiments of the present invention may include a computer-readable medium containing program instructions for performing various computer-implemented operations. The computer-readable medium may include program instructions, local data files, local data structures, etc., singly or in combination. The media may be those specifically designed and constructed for the present invention or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and ROM, RAM, flash memory, etc. It includes specially configured hardware devices to store and execute the same program instructions. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

Embodiments of the motor failure detection device disclosed in this specification may be applied to and implemented as a device for detecting a failure of a PM motor.

Embodiments of the motor failure detection device disclosed in this specification are usefully applied to a device that detects a failure by measuring the back electromotive force induced in the teeth constituting each phase of the motor and determining the stator/rotor eccentricity of the motor. It can be implemented.

Embodiments of the motor failure detection apparatus disclosed in this specification can be particularly usefully applied to and implemented in an apparatus for detecting failure of a motor with a rotationally symmetrical structure corresponding to a geometrically even number.

According to embodiments of the motor failure detection device disclosed herein, the back electromotive force of at least one pair of teeth constituting each phase of the motor is measured by detecting the voltage at both ends of the teeth without additional winding, thereby providing a separate configuration for measuring the back electromotive force. This has the effect of being able to detect a motor failure without any problems.

As a result, the motor failure detection device disclosed in this specification can not only improve structural limitations and limited design problems inside the motor, but also simplify the design for failure detection, thereby reducing costs. There is a possible effect.

In addition, according to embodiments of the motor failure detection device disclosed herein, the voltage is detected at both ends of a pair of teeth without an additional winding, and the back electromotive force is measured by calculating the difference between the two voltages, thereby producing a measurable back electromotive force without an additional winding. can be measured, and this has the effect of simplifying the measurement of back electromotive force and detection of motor failure.

Although specific embodiments according to the present invention have been described so far, it goes without saying that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the patent claims described below as well as equivalents to the claims of this patent.

As described above, although the present invention has been described with limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art will be able to make various modifications and modifications from these descriptions. Transformation is possible. Accordingly, the spirit of the present invention should be understood only by the scope of the claims set forth below, and all equivalent or equivalent modifications thereof shall fall within the scope of the spirit of the present invention.

10: winding 110: rotor hub
120: permanent magnet 130: stator core
140: winding 200: motor failure detection device
210: Back electromotive force measurement unit 211: Voltage detection unit
220: comparative analysis unit 230: failure detection unit

Claims (9)

a back electromotive force measuring unit that measures a back electromotive force induced in at least one pair of teeth among a plurality of teeth constituting each phase of the motor;
a comparative analysis unit that compares and analyzes the measured back electromotive force; and
It includes a failure detection unit that detects a failure of the motor based on the comparative analysis results,
The pair of strikes,
Two constituting the same image placed in positions facing each other,
The back electromotive force measuring unit,
Including a pair of measurement target teeth and a voltage detection unit that detects the voltage across both ends of each of the measurement target teeth at each measurement portion between each of the measurement target teeth and the teeth on both sides adjacent to each of the measurement target teeth, the voltage across both ends of each of the measurement target teeth Detect and measure the back electromotive force,
The measurement part is,
It includes four parts that transition from the measurement target tooth to the adjacent tooth,
The comparative analysis unit,
A motor failure detection device characterized in that the difference between the voltages at both ends of each of the measurement target values is calculated, and the measured back electromotive force is compared and analyzed based on the calculated results. delete According to claim 1,
The voltage detector,
A motor failure detection device characterized in that it is connected to a winding of the measurement target between the measurement target and the adjacent teeth, and directly detects voltage at both ends of the measurement target. delete delete According to claim 1,
The comparative analysis unit,
A motor failure detection device characterized in that the voltage waveforms at both ends of each of the measurement target values are compared and analyzed. delete According to claim 1,
The comparative analysis unit,
A motor failure detection device characterized in that the difference between the voltages across each of the measurement target values is calculated so that the fundamental wave components of the voltages across each of the measurement target values cancel each other out. According to any one of claims 1 and 8,
The calculated results above are:
A motor failure detection device, characterized in that the fundamental wave components of the voltage at both ends of each of the measurement target values cancel each other, and any component other than the fundamental wave component is added and increased.

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