KR100905971B1 - System and method for on-Line diagnostic of Generator-Motor - Google Patents

Abstract

The present invention relates to a power generation-motor diagnosis system and a method for monitoring and diagnosing the state of power-motor operation, the operation of a pumping power plant is promoted frequent stop, high utilization rate and aging equipment In-operation diagnosis of power generation-motor operation that can comprehensively evaluate and diagnose the progress of insulation deterioration of generator-motor stator winding, occurrence of interlayer short circuit of rotor winding, and eccentricity between stator and rotor during operation to ensure reliability. System and method.

Power Generation-Motors, Stator Windings, Rotor Windings, Eccentricity, Short Circuits, Insulation Degradation, Air Gap

Description

System and method for on-line diagnostic of generator-motor

The present invention relates to a system and method for diagnosis during power generation-motor operation that enables monitoring and diagnosis of power-motor operation. In particular, the present invention relates to a pumping plant in which frequent shutdowns, high utilization rates, and aging of equipment are promoted. In order to ensure the reliability of operation, the progress of insulation deterioration of the power generator-motor stator winding, the occurrence of interlayer short circuit of the rotor winding, and the eccentricity between the stator and the rotor are measured by sensors and evaluated based on the measurement results. The present invention relates to a diagnostic system and method for power generation-motor operation.

In the conventional method of diagnosis of power generation-motor stop, the diagnosis system in which the partial discharge of the stator winding, the interlayer short circuit of the rotor winding, and the gap between the stator and the rotor are installed alone is most of them.

Insulation diagnosis during power generation-motor stator windings performs insulation resistance, polarity index, AC current, dielectric loss tangent and partial discharge test.Insulation diagnosis of rotor winding also stops insulation resistance, polarity index and voltage sharing. In addition to the hassle of stopping the generator in order to perform the test, etc., the interlayer short circuit occurred during the operation of the power generator and the motor. .

In addition, the measurement of the gap between the generator-motor rotor and the stator has been difficult to measure during the generator-motor stop.

In order to evaluate the health of power generation-motors, the diagnostic system during operation has been very difficult to comprehensively assess the integrity of the stator and the rotor, the partial discharge of the stator windings, and the interlayer shorting of the rotor windings. The conventional technology has led to a problem that it takes a long time to comprehensively determine a diagnosis result and is difficult to manage trends.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its purpose is to comprehensively determine the insulation deterioration state of the power generation-motor stator windings, whether the interlayer short circuit occurs in the rotor windings, and the eccentricity between the stator and the rotor during the operation of the pumping power plant. The present invention provides a diagnostic system and method for power generation-motor operation that can quickly and accurately evaluate the health.

In addition, another object of the present invention is to diagnose the deterioration of the insulation of the generator-motor stator winding, the occurrence of an interlayer short circuit of the rotor winding, and the eccentricity between the stator and the rotor during the operation of the pumping station, thereby causing failure due to early detection of abnormal conditions. The present invention provides a diagnostic system and method during the operation of a power plant-motor that can greatly contribute to securing the reliability of generator facility operation by establishing preventive and planned and efficient predictive maintenance.

In addition, another object of the present invention is to provide a diagnostic system and method during the generation-motor operation to store the various alarm functions and the measurement results in a database so that the user can immediately check whether there is an abnormality of the facility and grant a trend management function. It is.

The development-motor diagnosis system of the present invention for achieving the object as described above,

Measurement unit for measuring the state of the power-motor, a diagnosis unit for diagnosing the state of the power-motor based on the measured value measured by the measurement unit and the command for receiving a command according to the diagnosis result and the instruction received from the diagnostic unit command In the diagnosis system of power generation-motor operation, which consists of a main management unit which stores performance and data,

The measuring unit may include a partial discharge sensor for measuring a partial discharge of a generator-motor stator winding during operation of a pumping station, an interlayer short sensor for measuring an interlayer short circuit of a rotor winding in the generator-motor, and between the stator and the rotor in the generator-motor. It consists of a pore sensor that measures the air gap.

In addition, the diagnosis unit is a partial discharge diagnostic module for diagnosing the insulation deterioration state of the stator windings based on the partial discharge value measured in the generator-motor stator windings during operation of the pumping station, measuring the interlayer short circuit of the rotor windings in the power-motors An interlayer short circuit diagnosis module for diagnosing whether an interlayer short circuit occurs based on a value and a pore diagnostic module for diagnosing an eccentricity based on a measured value of the gap between the stator and the rotor in the power generator-motor.

The diagnostic method during operation of the power-motor of the present invention for achieving the above object,

The first step of measuring the partial discharge of the stator winding of the generator-motor, the interlayer shorting of the rotor winding and the gap between the stator and the rotor through the three sensors of the measuring unit and transmitting the measured value to the diagnosis unit, the first step The diagnosis unit diagnoses the insulation deterioration state of the power-motor stator windings, whether the interlayer short circuit occurs in the rotor windings, and the eccentricity between the stator and the rotor based on the measured values transmitted from the measurement unit. A second step of checking whether or not the abnormality is confirmed after the second step, a third step of transmitting and storing data and a warning command to the main management unit, and a main management unit if the abnormality is not confirmed after the second step. Perform a fourth step of transmitting and storing data in the.

The diagnosis system and method during the operation of a power plant-motor according to the present invention comprehensively diagnoses the insulation deterioration state of the power-motor stator winding, the occurrence of an interlayer short circuit of the rotor winding and the eccentricity between the stator and the rotor during the operation of the pumping station. Health can be assessed quickly and accurately.

In addition, it is possible to prevent faults due to early detection of fault conditions and to predict and predict effectively by diagnosing the insulation deterioration state of the generator-motor stator winding, the occurrence of interlayer short circuit of the rotor winding, and the eccentricity between the stator and the rotor during operation of the pumping station. Establishing maintenance can greatly contribute to ensuring the reliability of the generator installation.

In addition, various alarm functions and measurement results are stored in a database so that the user can immediately check whether there is a malfunction.

The present invention will be described in more detail based on the accompanying drawings as follows.

In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. And the following terms are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user, the operator, etc. Accordingly, the meaning of each term should be interpreted based on the contents throughout the present specification. something to do.

1 is a block diagram showing a diagnostic system during operation of the power-motor according to the present invention.

As shown, the diagnosis system of the power generation-motor operation according to the present invention is largely divided into a measurement unit 10, a diagnosis unit 20, the main management unit 30.

The measuring unit 10 includes a partial discharge sensor 11 having a total of six units each installed in the generator-motor stator windings, two of which correspond to each other, an interlayer short sensor 12 installed in the generator-motor rotor windings, and a generator-motor. It consists of four air gap sensors (13) installed one by one at intervals of 90 ° between the stator and the rotor, and the partial discharge of the generator-motor stator windings in operation, the interlayer short-circuit of the rotor windings, and between the stator and the rotor. The voids can be measured.

In addition, the diagnosis unit 20 includes a partial discharge diagnosis module 21, an interlayer short circuit diagnosis module 22, and a gap diagnosis module 23, and is based on a partial discharge value measured in a power generation-motor stator winding in operation. Diagnosis of eccentricity is based on the insulation deterioration state of the stator winding, whether or not an interlayer short circuit is generated based on the value of the interlayer short circuit of the rotor winding in the generator-motor, and the value of the gap between the stator and the rotor in the power generator-motor. And the resulting value can be calculated.

The partial discharge diagnosis module 21 and the interlayer short circuit diagnosis module 22 include a peak detector, a filter and a differential amplifier, and the pore diagnosis module 23 converts a current into a voltage to measure a pore signal. The converter to convert is installed.

In addition, the main management unit 30 is composed of a gateway unit 31, the main server 32, the computer 33, the gateway unit 31 transmits the result value calculated by the diagnostic unit 20 by RS485 communication It receives and transmits to the control and main server 32, the main server 32 receives the result value from the gateway unit 31 by TCP / IP to transmit to the computer 33 and the result value is stored.

Figure 2 is a flow chart illustrating a diagnostic method during power generation-motor operation according to the present invention, Figure 3 is a graph showing the rotor winding interlayer short circuit data and magnetic flux density during power generation-motor operation according to the present invention.

As shown in FIG. 2, the partial discharge of the stator windings of the generator-motor, the interlayer shorting of the rotor windings, and the air gap between the stator and the rotor through the three sensors 11, 12, 13 of the measuring unit 10. Measure and transmit the measured value to the diagnostic unit 20 (ST1).

Thus, the measurement value measured by the measuring unit 10 is transmitted from the diagnosis unit 20 based on the measured value of the insulation deterioration state of the power-motor stator winding, whether the interlayer short circuit occurs in the rotor winding, and between the stator and the rotor. Diagnose the eccentricity and check the abnormality based on the result (ST2 ~ ST3).

In addition, if the abnormality is confirmed in the diagnosis unit 20 transmits and stores the data and warning command to the main management unit 30 (ST4, ST5), if the abnormality is not confirmed in the diagnosis unit 20 The data is transmitted to the manager 30 and stored (ST5).

Partial discharge measurement of the generator-motor stator windings in operation in the measuring unit 10 converts the data into the unit of mV since the input signal is the voltage V in the acquiring part of the data, and transmits the data to the diagnosis unit 20. The signals synchronized in the data processing part of the diagnosis unit 20 are classified by phase or magnitude, and the frequency for each magnitude and phase is determined to determine the number of partial discharge occurrences (NQN) and the partial discharge magnitude (QM). You can get it. In this case, the number of partial discharge occurrences (NQN) is a defect position by synchronizing the phase of the signal received from the sensor with the phase of the AC power supplied from the outside of the result of converting the partial discharge magnitude measured from the measuring unit 10 in mV units If the partial discharge signal appears differently during one cycle of alternating current (0 ° to 360 °), the number of partial discharge pulses of the momentarily changing partial discharge signal is summed up, and the partial discharge magnitude (QM) is the partial discharge. Indicates the value at which the pulse is highest.

In other words, the magnitude of the partial discharge and the number of partial discharges are analyzed in two dimensions to evaluate the degree of insulation deterioration, and the pattern is analyzed by representing the partial discharge magnitude, the number of generation and the phase of one cycle (0 ° to 360 °) in three dimensions. Defect location is analyzed.

Therefore, as described above, it is possible to predict the defect state by analyzing the partial discharge pattern in three dimensions by analyzing the partial discharge size, the number of occurrence and the phase in three dimensions.

In addition, the interlayer short measurement of the generator-motor rotor winding in operation in the measuring unit 10 measures the symmetrical magnetic flux distribution of the N pole and the S pole, and transmits the data to the diagnosis unit 20. In section 20, it can be seen how many times the interlayer short circuit has occurred in the windings of the plurality of rotor windings, and if the incidence of the interlayer short circuit exceeds 10% in the total number of rotor windings, the rewinding is determined.

Exciter overheating accident occurs because the excitation is continuously replenished as the magnetic flux is reduced due to the interlayer short circuit of the rotor winding.

Accordingly, the diagnosis unit 20 accurately analyzes the occurrence rate and position of the interlayer short circuit of the rotor winding to predict the increase in vibration and the exciter overheating accident in advance, so that the planned maintenance can be performed.

FIG. 3 is a graph illustrating rotor winding interlayer short circuit data and magnetic flux density during power generation-motor operation. As shown in FIG. 3, the vibration increase and the excitation overheating accident are represented in advance, and the flux data are shown in FIG. The location of extreme density is near the point where the Flux Probe data passes through '0'.

The reason for this is that the flux density is obtained as shown in the following [Formula 1].

[식 1]

[Equation 1]

In other words, since the Flux Probe data by 24 poles produces 12 similar waveforms, and the waveform of 1 cycle is repeated 12 times with similar signals with respect to the voltage [V] axis, the integral value is the Flux Probe data. The maximum value is obtained when passing near the '0' point.

In addition, the measurement of the air gap between the generator-motor stator and the rotor in operation in the measuring unit 10 is measured by the air gap sensor 13 between the stator and the rotor, and the measurement in the diagnosis unit 20. The current is converted into a distance from the data transmitted through the air gap sensor 13 of the unit 10, and this is calculated by Equation 2 below.

[식 2]

[Equation 2]

The linear section of [Equation 2] is 5-50 [mm] and is represented by 4-20 [mA] as a current, and only the distance within the linear section can be measured.

The measured current from the air gap sensor 13 is converted into a voltage by a current-voltage converter, reduced to current again in order to take advantage of the conversion of current and distance, and calculated by the empirical equation presented above.

Figure 4a is a computer diagram showing the partial discharge measurement of the generator-motor stator windings measured by the present invention, Figure 4b is a computer showing the interlayer short circuit measurement of the generator-motor rotor windings measured by the present invention Figure 4c is a diagram showing a computer measured air gap between the generator-motor stator and the rotor measured by the present invention.

As shown, the partial discharge measurement of the generator-motor stator windings, the interlayer short circuit measurement of the generator-motor rotor windings, and the void measurement between the generator-motor stator and the rotor measured by the present invention are What is actually shown is shown in sequence in FIGS. 4A to 4C. Here, the measurement of the partial discharge of the stator winding is to evaluate the degree of insulation deterioration by analyzing the partial discharge size and the number of partial discharges described in FIG. As a result of identifying the defect location by the partial discharge pattern analysis may refer to the values obtained through the process.
Likewise, the interlayer short circuit measurement of the rotor windings refers to the results including the twelve similarly shaped waveforms described in FIG. 3 and the maximum value thereof, and is referred to as the pore measurement between the stator and the rotor. May refer to a result including a value calculated by the conversion formula of the current and the distance described in FIG. 3.

1 is a block diagram showing a diagnostic system during operation of the power-motor according to the present invention.

2 is a flowchart illustrating a diagnosis method during generation of a motor according to the present invention.

3 is a graph showing rotor winding interlayer short circuit data and magnetic flux density during power generation-motor operation according to the present invention.

4A is a diagram showing a partial discharge measurement of a power-motor stator winding measured by the present invention on a display.

Figure 4b is a diagram showing the interlayer short circuit measurement of the generator-motor rotor windings measured by the present invention on the display.

Figure 4c shows on the display the measurement of the voids between the generator-motor stator and the rotor measured by the present invention.

<Description of the symbols for the main parts of the drawings>

10 ---- Main control unit 11 ---- Partial discharge sensor

12 ---- Interlayer short circuit sensor 13 ---- Air gap sensor

20 ---- Remote Console Server 21 ---- Partial Discharge Diagnostic Module

22 ---- Short Circuit Diagnosis Module 23 ---- Pore Diagnosis Module

30 ---- Main Administration 31 ---- Gateway Unit

32 ---- Main Server 33 ---- Computer

Claims (5)

The measuring unit 10 for measuring the state of the power-motor, the diagnostic unit 20 for diagnosing the state of the power-motor based on the measured value measured by the measuring unit 10 and instructing a command according to the diagnosis result and the In the power generation-motor operation diagnostic system comprising a main management unit 30 for receiving an instruction command from the diagnosis unit 20 and storing the command execution and data, The measuring unit 10 includes a partial discharge sensor 11 for measuring a partial discharge of the generator-motor stator winding during the operation of the pumping station; An interlayer short sensor (12) for measuring an interlayer short circuit of the rotor windings in the power-motor; In the power generation-motor is composed of a gap sensor 13 for measuring the gap between the stator and the rotor, The measurement unit 10 converts the measured partial discharge into mV units and transmits the measured partial discharge to the diagnosis unit 20, and the diagnosis unit 20 supplies the converted result and signal phase and AC power supplied from the outside. The number of partial discharge pulses (NQN) and the partial discharge magnitude (QM) of the partial discharge pulses, which are the result of summing the number of instantaneous partial discharge pulses by synchronizing the phases of the pulses, are obtained and analyzed in two dimensions to determine the degree of insulation degradation. Power generation-motor characterized by evaluating the partial discharge size, the number of occurrences, and the phase (0 ° to 360 °) of one cycle in three dimensions to predict a defect state (defect location) by partial discharge pattern analysis Diagnostic system during operation. The method of claim 1, The diagnosis unit 20 includes a partial discharge diagnosis module 21 for diagnosing an insulation deterioration state of the stator windings based on the partial discharge values measured at the power generation-motor stator windings during the operation of the pumping power plant; An interlayer short circuit diagnosis module (22) for diagnosing whether an interlayer short circuit occurs on the basis of a value of the interlayer short circuit of the rotor winding in the power generator-motor; Power generation-motor diagnosis system, characterized in that made of a pore diagnostic module (23) for diagnosing the eccentricity based on the measured value of the gap between the stator and the rotor in the power-motor. Through the three sensors (11, 12, 13) of the measuring unit 10 measures the partial discharge of the stator winding of the generator-motor, the interlayer short circuit of the rotor winding and the air gap between the stator and the rotor and the diagnostic unit 20 A first step ST1 of transmitting the log measurement value; After the first step, the diagnosis unit 20 deteriorates the insulation deterioration state of the power generation-motor stator winding, whether an interlayer short circuit occurs in the rotor winding, and the eccentricity between the stator and the rotor based on the measurement value transmitted from the measurement unit 10. Diagnosing and determining whether an abnormality occurs based on a result value (ST2 to ST3); A third step (ST4, ST5) of transmitting and storing a data and an alarm generation command to the main management unit 30 if the abnormality is confirmed after the second step; If the abnormality is not confirmed after the second step, the fourth step ST5 of transmitting and storing data to the main management unit 30 is performed. Diagnosis of the insulation degradation state of the power generation-motor stator winding of the second step synchronizes the result of the measured value converted from the measuring unit 10 in mV with the phase of the partial discharge signal and the phase of the AC power supplied from the outside. The number of partial discharge pulses (NQN) and the partial discharge magnitude (QM) of the partial discharge pulses, which are the result of summing the number of instantaneous partial discharge pulses, are calculated and analyzed in two dimensions to evaluate the degree of insulation degradation. A method for diagnosing power generation during operation of an electric motor, characterized by predicting a defect state (defect position) by partial discharge pattern analysis by displaying discharge magnitude, number of occurrences, and phase (0 ° to 360 °) of one cycle. delete The method of claim 3, wherein The occurrence of the interlayer short circuit of the power-motor rotor winding of the second stage is measured by measuring the symmetrical magnetic flux distribution between the north pole and the south pole to accurately analyze the incidence and position of the interlayer short circuit of the rotor winding, thereby increasing the vibration and the excitation overheating. A method for diagnosis during generation-motor operation, characterized in that for predicting in advance.

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