JP2007047184A - Dynamo-electric machine and method for measuring voltage being applied to its coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interlayer insulation diagnosis technique capable of discriminating between partial discharge in an interlayer insulation and partial discharge in an insulation to the ground, and diagnosing an insulation state. <P>SOLUTION: To each coil or each block comprising a plurality of coils of a dynamo-electric machine, a probe 2 for detecting partial discharge current from a coil to be diagnosed is connected, the partial discharge current detected by the probe 2 is derived via an interface device 540, the polarity of the derived partial discharge current is discriminated by a computer 510, it is discriminated whether the partial discharge current is caused by partial discharge by the interlayer insulation, or partial discharge in the insulation to the ground, and whether there is an abnormality in the interlayer insulation is determined by comparison with a reference value stored beforehand, and its result is outputted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for diagnosing interlayer insulation of a rotating electrical machine coil, and in particular, provides knowledge related to interlayer insulation for a newly designed rotating machine and contributes to operation while monitoring the insulation state of the rotating machine. The present invention relates to a technique for diagnosing interlayer insulation.

  In general, a rotating electrical machine is formed of a stator 181 and a rotor 182 as shown in FIG. A stator coil 160 of the rotating electrical machine is installed in the stator slot 183. When the coil 160 is removed from the slot, the shape shown in FIG. 39A is obtained. Further, as shown in the cross-sectional view of FIG. 39B, the coil 160 is formed by applying ground insulation 173 to a coil conductor bundle 172 obtained by winding a coil conductor 171 whose outer periphery is covered with an interlayer insulation 170 a plurality of times. Yes. The former interlayer insulation 170 insulates between coil conductors, that is, between windings. On the other hand, the ground insulation 173 insulates between the coil conductor 171 and the core having the ground potential.

  Generally, when operating a rotating electrical machine at a commercial frequency, (rated voltage) / √3 V is applied to ground insulation. On the other hand, only a voltage of several volts is applied to the interlayer insulation between the coil conductors. For this reason, conventional insulation diagnosis is mainly performed for ground insulation.

  On the other hand, in recent years, inverter driving of rotating electrical machines has been actively performed. In the inverter drive motor, for example, IEEJ Technical Report No. 739, p. As shown in FIG. 14, it is reported that a large voltage is shared by the interlayer insulation. In particular, in an inverter using an IGBT which is a high-speed switching element, a large voltage is applied due to interlayer insulation. For this reason, in an inverter-driven rotating electrical machine, not only ground insulation but also insulation diagnosis of interlayer insulation is required.

  Conventionally, as such an inter-layer insulation diagnostic apparatus, for example, an apparatus for detecting partial discharge which is one of degradation signals of inter-layer insulation, as disclosed in JP-A-8-122388 and JP-A-9-257862. There is. There is also a device for detecting an interlayer short-circuit state as disclosed in Japanese Patent Laid-Open No. 9-257862. In the former interlayer insulation diagnostic apparatus, a voltage is applied to the interlayer insulation by a surge power source such as a high-frequency high-voltage power supply or impulse, and various signals such as current, electromagnetic waves, and sound waves accompanying partial discharge are detected. On the other hand, in the latter interlayer insulation diagnostic apparatus, a surge voltage is applied to the coil, and a short circuit in the interlayer insulation is detected from the difference in the detection signal waveform generated due to the difference in the propagation time of the surge.

JP-A-8-122388 JP-A-9-257862

  In the former interlayer insulation diagnostic apparatus, when a voltage is applied to the coil, the voltage is applied not only to the interlayer insulation but also to the ground insulation. For this reason, not only interlayer insulation but also partial discharge in ground insulation occurs. However, the former method cannot distinguish between partial discharge in interlayer insulation and partial discharge in ground insulation. For this reason, it has been difficult to perform insulation diagnosis of interlayer insulation.

  On the other hand, the interlayer insulation diagnosis apparatus using surge voltage can detect only a complete interlayer short-circuit state as described in Japanese Patent Laid-Open No. 8-122388. For this reason, it is not sufficient as an insulation diagnosis for interlayer insulation.

  As described above, conventionally, with a rotating electrical machine, it has been difficult to diagnose insulation deterioration of interlayer insulation. Further, under such circumstances, there is a problem that it is difficult to drive a commercial frequency power supply or a used rotating electrical machine manufactured for an old inverter power supply with a new inverter power supply.

  An object of the present invention is to provide an interlayer insulation diagnosis technique capable of diagnosing an insulation state by distinguishing between partial discharge in interlayer insulation and partial discharge in ground insulation.

  The basic principle of the present invention is to distinguish between interlayer insulation and ground insulation partial discharge based on the polarity of the discharge current detected by the discharge current sensor. Thereby, an interlayer insulation diagnosis for distinguishing between partial insulation and interlayer insulation and an apparatus therefor are realized.

  For example, in the first aspect of the interlayer insulation diagnosis according to the present invention, detection is performed by the power supply line of the lead portion of the rotating electrical machine or the coupling capacitor connected to the power supply line and the discharge current sensor installed at the inter-coil connecting portion of the rotating electrical machine. The partial discharge between the interlayer insulation and the ground insulation is distinguished by the polarity of the partial discharge current.

  In the second mode, instead of attaching a discharge current sensor to the inter-coil connecting portion, the inter-coil connecting portion conductor and the ground are capacitively coupled to discharge the partial discharge current flowing from the inter-coil connecting portion conductor to the ground. Interlayer insulation diagnosis is performed by detecting with a current sensor. In this case, in particular, in a rotating electrical machine with a neutral point grounded, a discharge current sensor can be installed on the neutral point grounding wire.

  As another aspect of the present invention, for example, when measuring the ground voltage waveform of each coil, a measurement unit that distinguishes between partial insulation of interlayer insulation and ground insulation from the phase of the voltage waveform and the polarity of the discharge current is provided. It can also be realized by an interlayer insulation diagnostic device.

  Further, for example, instead of attaching the discharge current detection sensor to the inter-coil connecting portion or the capacitive connecting portion between the inter-coil connecting portion and the ground, the end portion on the opposite side of the inter-coil connecting side in the rotating electrical machine coil end portion It can also be realized by an interlayer insulation diagnostic device provided with a discharge current sensor.

  As described above, according to the present invention, the insulation state can be diagnosed by distinguishing between partial discharge in interlayer insulation and partial discharge in ground insulation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an interlayer insulation diagnostic apparatus according to the first embodiment. In this embodiment, the induction motor 10 will be described as an example used when performing an interlayer insulation diagnosis.

  In the interlayer insulation diagnosis apparatus of the present embodiment, the test power supply device 7 and the induction motor 10 are connected. In the induction motor 10, a coupling capacitor is disposed on the lead side of the first coil of any phase, and the coupling is performed. In response to the first current probe 1 for detecting the current flowing through the capacitor, the current probe 2 for detecting the current flowing through the stator coil connecting portion 14 of the induction motor 10, and the output signals of the current probes 1 and 2, And a diagnosis support apparatus 400 that enables diagnosis. The diagnosis support apparatus 400 uses the multi-channel high-pass filter (cutoff frequency 1 to 100 MHz) 3 for removing the power supply frequency component from the output signals of the current probes 1 and 2 and the output signal from which the power supply frequency component is removed. It has a logic discriminator 4 for making a logical judgment and a discharge detector 5 for detecting a discharge state.

  Specifically, in this embodiment, the U-phase first coil 11 of the induction motor 10 (6.6 kV, 500 kVA) is connected to the test power supply device 7 (6.6 kV, 200 kHz, sine wave), and V, W Phase first coil 13 is connected to ground. A coupling capacitor 6 (100 pF) is attached to the U-phase power supply line 9, the low-voltage side of the coupling capacitor 6 is connected to the ground, and the current probe 1 is installed on the connection line. On the other hand, the current probe 2 is installed at the connection portion 14 between the stator coils of the induction motor 10. FIG. 1 shows an example in which the current probe 2 is arranged at the connection portion 14 between the U-phase first coil 11 and the U-phase second coil.

  The output signals of the current probes 1 and 2 are input to a multi-channel high-pass filter (cutoff frequency 1 MHz) 3 to remove the power supply frequency component. Thereafter, the signal is input to the discharge detector 5 via the logic discriminator 4. As the discharge detector 5, for example, a digital oscilloscope (band 1 GHz, sampling frequency 4 GS / s) is used. The discharge detector 5 detects the discharge state and displays the result so that the coil can be diagnosed. That is, the discharge detector 5 functions as a device that supports insulation diagnosis.

  The test power supply device 7 has a high frequency power supply 7 a and an internal impedance 8. This internal impedance 8 functions as a protective resistor and a blocking impedance.

  The current probes 1 and 2 are constituted by, for example, a coil for detecting current and function as a sensor. Each of these current probes 1 and 2 has a structure in which a part of the coil can be opened and closed, and a detection target wire can be arranged in the coil. When a part of the detection target line can be attached and detached, the current probes 1 and 2 may not be able to be opened and closed. Further, one or both of the current probes 1 and 2 can be incorporated in the rotating machine in advance. When diagnosing such a rotating machine, a built-in current probe can be used.

  FIG. 4 shows an example of the logic discriminator 4. In the logic discriminator 4, the discharge currents of the current probes 1 and 2 are compared with the ground potential by the comparator 190, and are converted into polarity signals of 5V and 0V, respectively, of positive polarity and negative polarity. The polarity signal is input to the exclusive OR circuit 191 and the inverting circuit 192 when detecting the partial discharge of the interlayer insulation, and the output is input to the trigger terminal of the switch 194 that is turned on at the H level. . On the other hand, when detecting a partial discharge for ground insulation, the output of the exclusive OR circuit 191 is input to the trigger terminal of the switch 194 by the switch 193. Note that when the pulse width of the partial discharge signal is small, the output of the comparator 190 can be input to a monostable multivibrator to extract a signal having a pulse width for operating the logic circuit.

  The logic discriminator 4 can determine whether the partial discharge is a partial discharge due to interlayer insulation or a partial discharge due to ground insulation. FIG. 3 shows an example in which the interlayer insulating partial discharge current is discriminated as the output signal 26 by the logic discriminator 4. In FIG. 3, the interlayer insulation partial discharge current 22 is represented by a solid line, and the ground insulation partial discharge current 23 is represented by a broken line.

  Next, the principle and operation of the interlayer insulation diagnostic apparatus of the first embodiment will be described.

FIG. 2 shows a ladder equivalent circuit model of the induction motor coil and a partial discharge current path of interlayer insulation and ground insulation at the time of positive polarity discharge. In FIG. 2, for simplicity of explanation, one coil is represented by a T-type equivalent circuit of a ground insulation capacitance C _g , an interlayer insulation capacitance C _r , and a coil inductance L. The high frequency components of the partial discharge current flows through the capacitance C _r of the inter-layer insulating, low-frequency components to flow the inductance L of the coil, in particular, considered as one block parallel circuit portion C _r and L, the discharge The current path is shown. The polarity of the current probes 1 and 2 is such that the current flowing in the direction toward the test phase lead 27 is positive outside the rotating electrical machine, and the current flowing from the test phase lead 27 to the other phase lead 28 is positive inside the rotating electrical machine. Yes. In FIG. 2, it is assumed that either a partial discharge of the interlayer insulation or a partial discharge of the ground insulation is generated. The generation position is a partial discharge of the interlayer insulation at a position indicated by an asterisk 20, and Assume that a partial discharge of ground insulation occurs at a position indicated by 21.

  In the current probe 1 of the interlayer insulation diagnostic apparatus, the discharge currents of the interlayer insulation and the ground insulation have the same polarity. For this reason, it is not possible to distinguish between partial discharge in interlayer insulation and partial discharge in ground insulation. On the other hand, in the current probe 2, the partial discharge current in the interlayer insulation and the discharge current in the ground insulation have opposite polarities. However, when the polarity of the power supply voltage is reversed, the partial discharge currents of the interlayer insulation and the ground insulation are also reversed. For this reason, only the current probe 2 cannot distinguish between partial discharge in interlayer insulation and partial discharge in ground insulation. However, the partial discharge currents detected by the current probes 1 and 2 have the same polarity in the interlayer insulation partial discharge and the opposite polarity in the ground insulation partial discharge, as shown in Table 1, regardless of the discharge polarity, as shown in Table 1. .

  Therefore, in the logic discriminator 4, it is possible to distinguish between the partial discharge in the interlayer insulation and the partial discharge in the ground insulation by logically discriminating the combinations of polarities shown in Table 1 for the current probes 1 and 2. it can. That is, by the logic discriminator 4, only when the discharge currents of the current probes 1 and 2 have the same polarity, the signal of the current probes 1 and 2 is passed through the discharge detector to detect the partial discharge of the interlayer insulation. can do. On the other hand, a partial discharge of ground insulation can be detected by passing a signal through the discharge detector only when the discharge current pulse has a reverse polarity.

  The partial discharge current 24 detected by the current probe 1 and the partial discharge current 25 detected by the current probe 2 are input to the logic discriminator 4. The logic discriminator 4 makes a logical determination based on the above-described operation principle and outputs an output signal 26. In the example of FIG. 3, an interlayer insulation partial discharge current is detected.

  The above polarity discrimination is shown in Table 2 as a truth table. However, in the input of Table 2, the positive polarity of the current probe detection current is “1” and the negative polarity is “0”. In the output, "1" is set if true, and "0" is set if false.

  2 and 3 and Table 1 show the partial discharge discriminating action of interlayer insulation and ground insulation of the first coil. For other coils, a current probe is installed at the inter-coil connection at both ends of the coil, and the polarity of the discharge current is compared, whereby partial discharge in interlayer insulation and partial discharge in ground insulation can be distinguished. In addition, with multiple coils as one block, by installing a current probe at each of the power supply lines sandwiching each block, the capacitors connected to the power supply lines, and the inter-coil connection part, the interlayer insulation generated by the coils in the block It is possible to discriminate between the partial discharge and the partial discharge due to ground insulation. In addition, when installing a current probe in the extraction of a non-partial discharge measurement phase, a current probe can be installed in the ground wire which connects extraction and a ground.

  Furthermore, in the first embodiment, the ground insulation partial discharge generating coil can be specified based on the polarity of the partial discharge current, or the partial discharge generated from the specific coil can be measured. This is because in this embodiment, the discharge current polarities of the current probes installed at both ends of the ground insulating partial discharge generating coil are opposite in polarity.

  On the other hand, in the interlayer insulation partial discharge, regardless of which coil generates a partial discharge, all current probes detect a positive current in a positive discharge and a negative current in a negative discharge. For this reason, an interlayer insulation partial discharge generating coil cannot be found only by the polarity of the partial discharge current. However, the interlayer insulating partial discharge generating coil can be identified by measuring a delay in time when the discharge current reaches each current probe after the partial discharge occurs. This is because the discharge current is detected earliest by the current probe closest to the interlayer insulating partial discharge coil.

  Table 3 shows the current polarity of each current probe when the ground insulation partial discharge of the fourth coil occurs from the opening. The polarity of the discharge current is reversed at the ground insulation partial discharge generating coil. For this reason, the ground insulation partial discharge generation coil can be specified by examining the polarity pattern of the discharge current of each current probe or by scanning while reducing the number of coils in the test block and finding the coil whose polarity is reversed.

  FIG. 5A shows an example in which the discharge current pulses determined as the interlayer insulation partial discharge from the discharge current polarity pattern of Table 3 are displayed with the vertical axis representing current and the horizontal axis representing time. FIG. 5B shows the positional relationship between the interlayer insulating partial discharge generating coil and each current probe. The symbols in FIG. 5A correspond to the symbols indicating the current probe in FIG. 5B. The discharge current is detected earliest by the current probes 231 and 232 installed at both ends of the coil 230 (indicated by an asterisk in the figure) in which the interlayer insulation partial discharge has occurred. Moreover, the arrival time of the discharge current is delayed as the distance from the discharge generation source increases. Therefore, the interlayer insulation partial discharge generation coil can identify the interlayer insulation partial discharge generation coil by finding the current probe in which the discharge current is detected earliest. This method can be specified by triggering the rise (or fall) of each current pulse and comparing the rise (or fall) times as described above.

  In the apparatus described so far, the diagnosis itself is performed by an operator. However, the insulation diagnosis can be performed by the apparatus itself based on the discharge detection result. As such a system, there is a system using the information processing apparatus 500, for example, the system of FIG. 26, FIG. 28, FIG.

  FIGS. 6 to 9 show examples in which current probes are installed in all coils, interlayer insulation and ground insulation partial discharge generation sources of each coil are identified from the polarity pattern and discharge current arrival time, and each partial discharge characteristic is measured. Show. On the other hand, FIG. 10 and FIG. 11 show search flowcharts for searching for coils whose polarity is reversed by scanning while reducing the number of coils in the test block. A program for realizing this flowchart is stored in an external storage device 514 of a computer 510 described later. For this search, the multi-channel high-pass filter 3 and the logic discriminating circuit 4 shown in FIG. 1 are provided corresponding to the current probes installed for all the coils. In addition, a device for measuring a change in discharge time is similarly installed. In addition, about these apparatuses, the apparatus which does not need to be used simultaneously can reduce a number by switching and using. Then, via the interface device 540 (see FIG. 37) that converts the obtained signal into a digital processable data, the computer 510 (see FIG. 37) retrieves the signal and performs subsequent data processing, screen display processing, and the like. The configuration is to be performed. Examples of the screen display processing include screen display illustrated in FIGS. 6 to 9 and an instruction operation for the screen display.

Here, the configuration of the computer 510 will be described. As shown in FIG. 37, the computer 510 includes a central processing unit (CPU) 511, a read only memory (ROM) 512, a random access memory (RAM) 513, an external storage device 514 configured by a hard disk device and the like. And have. The external storage device 514 stores an operating system, various application programs, and the like as programs executed in the computer 510. A typical example of the application program is a diagnostic program executed in the present invention. In addition, as data, for example, various measurement data described later and various values obtained from the measurement data are stored. As will be described later, these data are processed by the computer 510 and used for display in a format such as a characteristic diagram. An example of processing by the computer 510 is shown in FIG.
This is shown in FIG. 31, FIG. The process will be described later.

  Connected to the computer 510 are an input device such as a keyboard 521 and a mouse 522, a display device 530 such as a liquid crystal display, and an interface device 540 that receives a measurement value and outputs a signal for controlling the measurement device. . The information processing system 500 is configured including the computer 510 and these devices. The information processing system 500 can be configured by a general computer system. In addition, it can be configured using a control computer. It can also be configured using a dedicated computer. Here, examples of the measuring device include a first coil 1, a second coil 2, a test power supply device 7, and a plurality of second coil 2 selection switching devices. Moreover, the diagnosis support apparatus 400 shown in FIG. 1 can also be used as a measurement apparatus.

  The interface device 540 includes a multi-channel high-speed A / D converter 541, a digital filter 542, and the like. Moreover, although not shown in figure, the transmission / reception driver for transmitting / receiving a signal between measuring devices is provided. Further, although not shown in the figure, it also has a circuit for transmitting a command from the computer 510.

  6 to 9 are diagrams showing examples of screens showing measurement results. Both are shown as examples of explanation screens displayed on the display device 530 (see FIG. 37) connected to the computer 510. In the example of FIG. 37, the detection data is taken into the computer 510 via the interface device 540 and displayed by processing using a program and data prepared in advance in the external storage device 514. For example, EMTP (Elector-Magnetic Transients Program) is used as the program.

  6 to 9, a selection icon group 5310 is displayed along the lower edge of each screen 5300, and a screen to be displayed can be selected by clicking one of them. In addition, on the upper left side, a function explanation section 5320 including display of symbols f6 and f7 indicating function keys assigned in advance and explanation thereof is displayed. An area 5330 for displaying a characteristic diagram or the like is set in the upper part of the screen 5300. By operating the necessary keys among the function keys f6 and f7 displayed on the respective screens with the keyboard 521, it is possible to selectively display the characteristic diagrams assigned thereto. In this embodiment and other embodiments described later, function keys are displayed as icons. As a result, the mouse 522 can be used to select the function by positioning a pointer (not shown) on the corresponding function key and clicking.

  As the selection icon group 5310, for example, in FIG. 6, [FIG. B], [FIG. C], [FIG. D], [v setting], [n setting], [ground], [coil], [save] , [Diagnosis] and [Exit] icons are displayed. These icon groups are displayed in a state where a part thereof is changed depending on the displayed screen.

  In FIG. 6, ground voltage display <ground insulation maximum discharge charge amount−voltage characteristic> is assigned to the function key f <b> 6, and coil shared voltage display <interlayer insulation maximum discharge charge amount−voltage characteristic> is assigned to f <b> 7. Yes. In the current display state of FIG. 6, f7 is selected, FIG. A-1 (coil sharing voltage distribution) is displayed in the left region 5331 of the characteristic diagram display region 5330, and FIG. A-2 (interlayer insulation maximum) is displayed in the right region 5332. Discharge charge amount-voltage characteristics) are displayed. Here, in FIG. A-1, the target coil is represented by a figure, for example, a square, and the connection state of the coil is connected by the number corresponding to the figure representing the coil for each phase of UVW, The connected state is schematically displayed. On the other hand, in A-2, the characteristic is shown with the graph. In addition, when there are many coils, you may describe similarly per coil block.

  FIG. 7 shows a display screen after the icon 5311 of [FIG. B] displayed on the screen in FIG. 6 is clicked. In this screen, the function key f6 is selected. In FIG. 7, the message “Click to display the maximum discharge charge amount-voltage characteristics” is displayed on the screen in the state where FIG. B-1 is displayed in the left region 5331, and this portion is the selection key. It has become. A similar display is also displayed in FIGS.

  In FIG. 7, in the left area of the characteristic diagram display area 5330, as in FIG. 6, a figure representing a coil is connected in a number corresponding to each phase of UVW, and a star-connected state is schematically displayed. Yes. However, FIG. 7 shows a state in which the coil is selected by positioning the mouse pointer MP on one of the coils and clicking the button of the mouse 522. That is, the display mode of the graphic representing the selected coil is changed to clearly indicate that it is selected. In the case of FIG. 7, for the sake of convenience, the figure representing the coil is represented with a hatched state. Of course, when another coil is selected, a diagonal line is added to the figure showing the other coil. On the other hand, in the right region 5332 of the characteristic diagram display region 5330, FIG. B-2 (coil maximum discharge charge amount-voltage characteristic) for the selected coil is displayed. This display mode is basically the same in FIGS. 8, 9, 27, 29, and 30.

  In the process of FIG. 10, first, m = 0 and n = (U, the number of V-phase coils) are set (step 101), and a partial discharge in interlayer insulation and a partial discharge in ground insulation are identified (step 102). ). Interlayer insulation partial discharge can be distinguished from ground insulation partial discharge because the polarity of the discharge current detected by all current probes is the same. This detection can be performed by taking in the result obtained in the logic discriminator 4 described above. Of course, without using a logic discriminator, each detection signal can be taken into a computer and can be identified by determining their polarity like a logic discriminator.

  When an interlayer insulation partial discharge is measured, this search program displays a screen recommending that “Install a large number of current probes and identify the generated coil from the difference in the partial discharge pulse detection time of each current probe”. It is displayed on the device 530 and the process ends (step 109a).

  When ground insulation partial discharge is measured, this maximum discharge charge amount is set as the trigger charge amount, and the coil is found by reducing the interval between the coupling capacitor and the current probe installed in the non-partial discharge measurement phase one by one from both sides. (Steps 105-109c).

  In the process of FIG. 11, first, m = 0 and n = (U, the number of V-phase coils) are set (step 111), and the partial discharge of the interlayer insulation and the ground insulation is identified (step 112). Interlayer insulation partial discharge can be distinguished from ground insulation partial discharge because the polarity of the discharge current detected by all current probes is the same. When an interlayer insulation partial discharge is measured, this search program displays a screen recommending that “Install a large number of current probes and identify the generated coil from the difference in the partial discharge pulse detection time of each current probe”. It is displayed on the device 530 and the process ends (step 119).

  When ground-isolated partial discharge is measured, this maximum discharge charge amount is used as the trigger charge amount, and the interval between the current probe installed in the coupling capacitor and the non-partial discharge measurement phase is divided into two, and the interval between the current probes is reduced. A corresponding coil is found (steps 113 to 118).

  Note that in both the process of the flowchart shown in FIG. 10 and the process of the flowchart shown in FIG. 11, in particular, when a high frequency voltage is applied and the voltage is concentrated on the outlet, partial discharge is generated from the non-partial discharge measurement phase. Therefore, if the current probe on the opposite side of the coupling capacitor is installed in the coil connected to the neutral point, the number of search coils is reduced, and the ground insulation partial discharge generating coil can be found faster.

Interlayer insulation partial discharge charge is calibrated by using a battery-type floating potential charge calibrator and injecting calibration charges in parallel to one coil via the capacitance of the insulation layer between the coils. it can. However, the injected charge amount in this case is Q ₀ , the charge calibrator indicated value is Q ₀ , the capacitance of the series capacitor of the charge calibrator is C ₀ , and the capacitance of the insulating layer between the coils is C _s . Injected charge amount Q is the first coil of the lead
_{Q = C s / (C 0} + C s) Q 0
It becomes. Otherwise,
_{Q = C s / (2C 0} + C s) Q 0
It becomes.

  On the other hand, the partial discharge charge amount for ground insulation may be calibrated by injecting a calibration charge into the outlet of the rotating electrical machine, as in the prior art. However, it is desirable to calibrate between each coil via the capacitance of the inter-coil connecting portion insulating layer. In addition, in the equivalent circuit model of a rotating electrical machine as shown in FIG. 2, both the interlayer insulation and the ground insulation are perpendicular to each other, in which capacitors that are sufficiently smaller than their respective capacitances are connected in series in parallel with the interlayer insulation or the ground insulation of each coil. It can also be calibrated by connecting a wave power supply. That is, the voltage generated in the discharge detection probe is calculated using EMTP and the like, and from the ratio of the discharge charge amount obtained from the product of the square wave voltage and the capacitance of the capacitor connected to the square wave power supply and the discharge probe generation voltage, A voltage charge calibration coefficient may be obtained and calibrated.

As for the circuit constant of the equivalent circuit, the ground insulation capacitance C _g is measured by measuring the capacitance between the coil conductor of one coil and the ground electrode grounded on the ground insulation surface with an impedance measuring instrument such as an LCR meter. Is obtained. Further, the inductance L and the interlayer insulation capacitance C _r are measured by measuring the impedance of the start point and end point of the coil conductor of one coil, and the inductance from the impedance and frequency on the lower frequency side than the resonance frequency of the inductance of the interlayer insulation and the ground insulation. I asked L, and the addition, it is possible to obtain the interlayer insulating capacitance C _r from the high-frequency side impedance.

  The relationship between the voltage shared between the interlayer insulation and ground insulation of each coil and the partial discharge characteristics can be determined by installing a surface potential sensor at the connection between the coils and measuring the shared voltage or by using an EMTP or the like in an equivalent circuit model of a rotating electrical machine. It can be obtained by calculating the shared voltage of each part when a voltage is applied, obtaining the applied voltage of interlayer insulation and ground insulation, and comparing with the partial discharge characteristics.

  In the first embodiment, the U-phase partial discharge is measured using U-VW charging, but insulation diagnosis of each phase can be performed by using V-WU and W-UV charging. In particular, the impedance of the surge impedance of the coil (several hundreds to several kΩ) is connected to the lead of the non-partial discharge measurement phase (in the first embodiment, V and W phase lead), and the partial discharge is connected to the ground. This is desirable because current reflection vibration can be suppressed. However, if the attenuation of the partial discharge in the rotating electrical machine is large and the influence of reflection is small, there is no problem with either direct grounding or non-grounding.

  In this embodiment, the test is performed for each phase. However, UV-W, VW-U, WU-V phase charging or UVW three-phase batch charging may be used, and a plurality of phases may be tested collectively. .

In the interlayer insulation diagnostic apparatus of the first embodiment, a 200 kHz high frequency power supply is used as the power supply, but a voltage can be applied to a required place in the rotating machine by applying high frequency voltages of various frequencies. In particular, when the voltage is concentrated on the coil near the lead, the frequency of the power supply voltage is determined using the inductance L, interlayer insulation capacitance C _r , and ground insulation capacitance C _g of one coil in FIG.

Is desirable.

Further, when the circuit constant is not known, 1 measures the impedance between the start and end points of the coil conductors of the coils, it is possible to obtain the resonance frequency of the inductance L and the interlayer insulating capacitance C _r. Almost the same result can be obtained by applying a high frequency equal to or higher than the obtained resonance frequency. This is because, in a general rotating electric machine, the ground insulation capacitance C _g is smaller than the interlayer insulation capacitance C _r, and therefore the ground insulation capacitance C _g can be ignored. considered to become a parallel resonance frequency of the inductance L and the interlayer insulating capacitance C _r.

  12A and 12B show examples of potential distribution measurement when the applied voltage frequency of a rotating electrical machine having a resonance frequency of 100 kHz is changed. FIG. 12A shows the change of the coil ground voltage with respect to the coil number from the lead. On the other hand, FIG. 12B shows the change of the coil sharing voltage with respect to the coil number from the lead. When diagnosing interlayer insulation of all coils at once, the power supply frequency may be set lower than the resonance frequency and the voltage distribution may be made equal.

  When a high-frequency voltage is applied, a large-capacity power source is required because the charging current flowing through the ground-insulated capacitance is large. However, testing with a large-capacity power supply is not preferable from the viewpoint of energy saving. For this reason, in the high-frequency power source of the interlayer insulation diagnostic apparatus of the present invention, an inductive load 31 is connected in parallel to the rotating electrical machine (capacitive load at high frequency) and the coupling capacitor 30 as shown in FIG. As a result, the current capacity of the power supply can be reduced. Alternatively, as shown in FIG. 13B, the output voltage of the power supply can be reduced by connecting an inductive load 31 in series and causing series resonance. In addition, the power supply capacity can be reduced by using an intermittent sine wave as shown in FIG. 14A instead of a continuous sine wave, and a waveform that decays with time as shown in FIG. 14B. . In addition to the high-frequency power source, a surge power source such as an impulse, a triangular wave, and a rectangular wave, and an inverter power source can be used as the power source. In particular, since an inverter power supply can be used, the interlayer insulation diagnosis apparatus of the present invention can be installed in a rotating electrical machine, and interlayer insulation diagnosis can be performed even while the inverter is driven.

  In the first embodiment, a surge power supply can be used in the interlayer insulation diagnostic apparatus. For this reason, the conventional interlayer short circuit test can also be performed. In addition, it is possible to check whether there is a coil short-circuited between the layers after the dielectric strength test of the interlayer insulation. However, in the conventional interlayer short-circuit diagnosis apparatus, even if the presence of the interlayer short-circuit coil can be detected, it is difficult to specify the interlayer short-circuit coil. However, in the interlayer insulation diagnosis apparatus according to the first embodiment, as described above, by measuring the voltage-current characteristics of each coil with the surface potential sensor and the discharge current sensor installed in each coil, A short circuit coil can be identified.

  FIG. 15 shows voltage and current characteristics of the interlayer short-circuit coil and the healthy coil. In the healthy coil 201, when the current flowing through the coil is increased, the coil sharing voltage is also increased in proportion thereto. On the other hand, in the interlayer short-circuit coil 200, the generated voltage is smaller than that of the healthy coil, and the voltage is almost zero even when the current increases. In the healthy coil 201, as shown in FIG. 16B, impedance is generated by self-inductance. On the other hand, in the interlayer short-circuit coil 200, as shown in FIG. 16A, a short-circuit current (turns −1) times flows in the closed circuit formed in the short-circuit portion in a direction to cancel the input current, An equivalent state occurs, and the impedance is significantly reduced. For this reason, in the interlayer short-circuit coil 200, the generated voltage is smaller than that of the healthy coil, and the voltage does not increase even if the current increases.

  In the first embodiment, the coupling capacitor 6 is a 100 pF capacitor. However, it is preferable to use a capacitor having a large capacity because the partial discharge detection sensitivity is improved for both interlayer insulation and ground insulation. In particular, if the stray capacitance of the power supply line is about the same as the capacitance of the coupling capacitor, the partial discharge detection sensitivity does not decrease even if the coupling capacitor is removed. For this reason, when the stray capacitance of the power supply line can be used, the size of the device can be reduced. As described above, when the coupling capacitor is not used or when it is difficult to install the current probe on the grounding line of the coupling capacitor, the current probe is installed on the power supply line.

  In the present embodiment, the stray capacitance of the power supply line is connected in parallel to the ground insulation. Furthermore, by inserting a capacitor in parallel, the partial discharge detection sensitivity of the interlayer insulation can be selectively improved. For this reason, when it is desired to selectively diagnose interlayer insulation, it is desirable to insert a parallel capacitor.

  As the current probe for detecting discharge used in the first embodiment, a Hall element type or a CT type can be used. In addition, a Rogowski coil, high frequency CT, etc. can be used. In any case, those having excellent high frequency characteristics with a frequency band of 1 MHz or more, desirably 10 MHz or more are desirable.

  In this embodiment, a high-pass filter is used. However, when the power supply frequency is constant, a frequency cutoff filter called a notch, band rejection, band elimination filter, or the like may be used. In addition, the cutoff frequency of the high-pass filter can be lowered by using a filter with a sharp attenuation slope, so that the cutoff frequency can be lowered and more frequency components of the partial discharge signal can be passed. It is desirable to use an analog or digital filter having an attenuation gradient of / oct or more. Note that the background noise of filters and measuring instruments increases in proportion to √ (bandwidth), so it is desirable to limit the frequency band of filters and measuring instruments to the band of the current probe or lower.

  In the first embodiment, a logic discriminator is used for discrimination between partial discharge in interlayer insulation and partial discharge in ground insulation. In addition, an analog circuit such as an adder or a subtractor can be used. That is, in Table 1, since the partial discharge of the interlayer insulation has the same polarity in the current probes 1 and 2 and the partial discharge of the ground insulation has a reverse polarity, the partial discharge signal of the interlayer insulation is displayed in the adder, and the ground discharge is performed in the subtractor. The partial discharge signal can be output to the discharge detector 5. In particular, when detecting partial discharge of interlayer insulation, the current probe installed on the low voltage side of the coupling capacitor and other current probes have the opposite polarity of the power frequency component, while the partial discharge signal has the same polarity. Therefore, the power supply frequency component can be canceled by inserting an adder before the filter. Therefore, the cutoff frequency of the filter can be lowered, and more signal components can be passed. As the adder and subtracter, a transformer having divided windings can be used in addition to a semiconductor circuit such as an operational amplifier.

  As the discharge detector 5, a high-speed analog / digital oscilloscope, a high-speed A / D converter, an impulse voltmeter, or the like having a band higher than that of the current probe can be used. Especially when a digital oscilloscope or A / D converter is used, the logic discriminator and filter circuit in the previous stage are replaced with polarity discrimination, logic gate, digital filter function, etc. built in the digital oscilloscope or A / D converter. You can also Alternatively, data measured by a digital oscilloscope or A / D converter may be transferred to a computer, and logical discrimination and filtering may be performed by a program on the computer. That is, the discharge detector 5 may be configured by an information processing system 500 shown in FIG. 37, for example.

  Although the induction motor is used as the application target of the above embodiment, the present invention can also be applied to interlayer insulation diagnosis of other rotating electrical machines such as a synchronous machine.

  Next, a second embodiment of the present invention will be described. FIG. 17 shows an interlayer insulation diagnosis apparatus according to the second embodiment. In this embodiment, instead of installing the current probe 2 in the inter-coil connection portion in the first embodiment described above, an electrode 40 is installed on the surface of the inter-coil connection portion insulating layer, and the ground voltage is between the electrode and the ground. The measuring capacitor 41 is inserted, and the inter-coil connecting portion conductor and the ground are capacitively coupled by the capacitance 42 of the inter-coil connecting portion insulating layer and the ground voltage measuring capacitor 41, and from the inter-coil connecting portion conductor. A discharge current flowing to the ground is detected by the current probe 2. However, in the polarity of the current probe in the second embodiment, the direction of the current flowing from the power supply side to the ground is positive. In particular, in a rotating electrical machine having a neutral point grounded, a current probe can be installed on the neutral point grounding line without capacitively coupling the inter-coil connection portion and the ground. Further, for the extraction of the non-partial discharge measurement phase, a current probe can be installed on the ground line connecting the extraction and the ground.

  Also in the present embodiment, the diagnosis support apparatus 400, the coupling capacitor 6, and the test power supply apparatus 7 are used. The diagnosis support apparatus 400 includes a multi-channel high-pass filter 3, a logic discriminator 4, and a discharge measuring device 5. Further, the collection and processing of data and the diagnosis can be performed by using the information processing system described above.

The operation of the interlayer insulation diagnostic apparatus according to this embodiment will be described below. FIG. 18 shows a ladder equivalent circuit model of the induction motor coil and a partial discharge current path of interlayer insulation and ground insulation. In the model shown in FIG. 18, like the model shown in FIG. 2, in particular, a parallel circuit of _Cr and L is considered as one block, and a discharge current path is shown. In this embodiment as well, as in the first embodiment, the partial discharge currents between the interlayer insulation and the ground insulation cannot be discriminated only by using the current probes 1 and 2 alone. However, in the second embodiment, as shown in Table 4, the polarities of the current probes 1 and 2 are reversed in the interlayer insulation partial discharge, and the same polarity in the ground insulation partial discharge.

  Therefore, by distinguishing the polarity of the partial discharge current detected by the current probes 1 and 2 with the logic discriminator 4 as in the first embodiment, it is possible to distinguish between the partial discharge of the interlayer insulation and the ground insulation. However, in this embodiment, since the discharge current polarities of the interlayer insulation and the ground insulation are opposite to those of the first embodiment, the truth table in Table 2 and the logic discrimination circuit in FIG. The criterion for ground insulation is reversed. The use of the adder and subtracter described in the first embodiment is also reversed.

  In the second embodiment, an interlayer insulation partial discharge generating coil can be specified from the polarity of the partial discharge current, or a partial discharge generated from the specific coil can be measured. This is because in the second embodiment, as shown in Table 5, the discharge current polarities of the current probes installed at both ends of the interlayer insulating partial discharge generating coil are reversed. This corresponds to the fact that the ground insulation partial discharge generating coil can be detected from the polarity of the partial discharge current in the first embodiment. Therefore, in the second embodiment as well, the discharge current polarity pattern of a plurality of current probes is examined, or scanning is performed while reducing the number of coils in the test block, and a coil whose polarity is reversed is found. Can be identified.

  In addition, as a search algorithm for specifying a partial discharge generating coil, the search algorithm of the first embodiment shown in FIGS. 10 and 11, that is, in the flowcharts shown in FIGS. it can.

  As described above, in the second embodiment, since the interlayer insulating partial discharge generating coil can be specified, it is possible to detect and remove the coil in which the deterioration of the interlayer insulation has progressed. In the second embodiment, the ground insulation partial discharge generating coil can be specified by measuring a delay in time when the discharge current reaches each current probe after the ground insulation partial discharge is generated.

  Since the ground voltage measuring capacitor 41 is provided in the second embodiment, the capacitance of the capacitor 41 and the connection between the coils can be connected without providing a new surface potential sensor as in the first embodiment. The coil ground voltage and the coil shared voltage can be measured by the capacity partial pressure with the electrostatic capacity 42 of the partial insulating layer. Further, even if the ground voltage measuring capacitor 41 is not connected and the electrode 40 provided on the surface of the insulating layer between the coils is directly connected to the ground and the current probe 2 is installed on the connecting wire, It is possible to distinguish between ground insulation. In this case, an end discharge occurs in the electrode 40 provided on the surface of the insulating layer between the coils, but the end discharge is suppressed by applying an electric field relaxation paint to the electrode end or arranging an electric field relaxation electrode. it can.

  Further, in the case of detecting discharge current by capacitive coupling between the inter-coil connection portion and the ground for two or more inter-coil connection portions, the end discharge can be distinguished from the partial discharge of the interlayer insulation and the ground insulation. This is because, as shown in Table 6, the polarity of the discharge current of the current probe is reversed between the inter-coil connection where the end discharge occurs and the inter-coil connection located on both sides thereof. Therefore, by finding an inter-coil connection portion in which the polarity of the partial discharge current is different from that of the current probe installed in the inter-coil connection portion located on both sides, an end discharge generation source can be specified and an electric field relaxation process can be performed. In addition, this can be implemented by discriminating from the discharge current polarity pattern of a plurality of current probes as described above, or by scanning while reducing the number of coils in the test block.

  FIG. 19 shows a flowchart in which an end discharge generating coil identification sequence is added when the procedure shown in FIG. 10 is used as a search method for an interlayer insulating partial discharge generating coil. When the test block is first made large, the end discharge is regarded as the same as the ground insulation partial discharge, and can be distinguished from the interlayer insulation partial discharge. Further, since the polarities of all current probes are the same in the ground insulating partial discharge, it can be distinguished from the end discharge. The procedure from steps 1901 to 1908 is the same as the procedure shown in FIG. However, since there is a difference in installation of the probe, the searched result is different in that it is an m-th coil interlayer insulation partial discharge (step 1909) and an n + 1-th coil interlayer insulation partial discharge (step 1910). On the other hand, Step 1911 to Step 1920 are an end discharge generating coil identification sequence. Processing from step 1911 to step 1915 is performed in the same procedure as from step 1903 to step 1907. In step 1915, if the discharge current polarities are equal between the current probe #m and the coil #n, it is determined whether the coil #n is (n = m + 1) (step 1916), and (n = m + 1). If there is, it is determined that there is a ground insulating partial discharge (step 1917). On the other hand, if the coil #n is not (n = m + 1), the process returns to step 1914.

  The search method corresponding to FIG. 11 can also distinguish between interlayer insulation, ground insulation partial discharge, and end discharge by adding an identification sequence of ground insulation partial discharge and end discharge after identifying ground insulation and interlayer insulation partial discharge. .

  As in the first embodiment described above, a Hall element type, a CT type current probe, a Rogowski coil, and a high-frequency CT can be used for the discharge current sensor of the second embodiment. In addition, resistors can be used. When measuring the amount of discharge charge instead of measuring the discharge current, the discharge charge sensor uses a CR detection circuit formed of a resistor and a capacitor, and an LCR detector formed of a resistor, a capacitor, and an inductance. it can. When the partial discharge is tuned and detected by the LCR detector, the partial discharge can be measured with higher accuracy by further providing a tuning amplifier and a detection circuit between the logic discriminator and the discharge detector.

  On the other hand, when the partial discharge is detected while measuring the ground voltage of the coil as in the second embodiment or the first embodiment, as shown in FIG. When the phase is -90 ° to 90 °, positive discharge is performed, and when the phase is 90 ° to 270 °, negative discharge is performed. By the way, when a discharge occurs in the first coil as in the first embodiment and the second embodiment, in the current probe 2, the discharge currents of the interlayer insulation and the ground insulation have opposite polarities. For this reason, if a logic discriminator is used that allows only a negative partial discharge pulse to pass from -90 ° to 90 ° and passes a positive partial discharge pulse from 90 ° to 270 °, partial discharge of interlayer insulation can be achieved. Can be detected. Further, if the polarity gate of the logic discriminator is reversed, the partial discharge of the ground insulation can be detected. Therefore, at least the current probe 1 provided on the ground line of the coupling capacitor can be removed. At the same time, the coupling capacitor can be removed, and the device can be downsized.

  Table 7 shows the ground voltage and interlayer insulation, the discharge polarity of the ground voltage partial discharge, and the polarity of the discharge current detected by the current probe 2. In the current probe 2, a positive discharge is detected in the positive discharge of the interlayer insulation, and a negative discharge current is detected in the negative discharge. On the other hand, the ground insulating partial discharge current has a polarity opposite to that of the interlayer insulating partial discharge current. Therefore, if -90 ° to 90 ° is “0”, 90 ° to 270 ° is “1”, the positive polarity of the current probe detection current is “1”, and the negative polarity is “0”, the truth values shown in Table 8 As shown in the table, interlayer insulation partial discharge can be identified by Exclusive OR, and ground insulation partial discharge by vice versa. However, in the output of Table 8, if it is true, it is set to “1”.

  FIG. 21 shows a circuit example of a logic discriminator that distinguishes between partial insulation and interlayer insulation partial discharge from the phase of the ground voltage and the discharge current polarity of the current probe 2. In this logic discriminator, the discharge current signal of the current probe 2 and the ground voltage signal are compared with the ground potential by the comparator 210 and converted into polarity signals of 5V and 0V, respectively, of positive polarity and negative polarity. The polarity signal of the ground voltage is input to the delay circuit 211 and delays the π / 2 phase. As the delay circuit 211, for example, a monostable multivibrator can be used. The output of the delay circuit 211 is input to the exclusive OR circuit 212 together with the polarity signal of the current probe 2. The output of the exclusive OR circuit 212 is input as a trigger of the switch 214 that is turned ON at the H level by the switch 213 when detecting the interlayer insulation partial discharge. On the other hand, when measuring the ground insulation partial discharge, the output of the exclusive OR circuit 212 is input to the inverting circuit 215 and then input to the switch 214 as a trigger. In FIG. 20, the example which extracted the interlayer insulation partial discharge from the ground voltage waveform and the partial discharge pulse train was shown.

  FIG. 22 shows an interlayer insulation diagnosis apparatus according to the third embodiment. In the interlayer insulation diagnosis apparatus of the third embodiment, the current probe 61 corresponding to the current probe 2 of the inter-coil connection portion of the first embodiment is connected to the coil on the opposite side of the inter-coil connection portion at the rotating electrical machine coil end portion. It is installed in the end part 60. Hereinafter, in the third embodiment, a discrimination action between interlayer insulation and ground insulation will be described.

FIG. 23 shows an equivalent circuit model of one coil and a partial discharge current of interlayer insulation and ground insulation. 1 coil of the rotary electric machine is formed of a plurality of turns, the electrostatic capacitance c _r of the interlayer insulation between the winding turns is, the electrostatic capacitance c _g of ground insulation is present between turns and ground. For this reason, the equivalent circuit of FIG. 23 is established. On the other hand, since the current probe 61 installed in the coil end portion is linked to all the turn conductors of one coil, it can be considered that the current probe 61 is installed in each turn conductor. When a partial discharge occurs in such a coil, a partial discharge current flows through the path of FIG. That is, in the high frequency region, since the impedance of the capacitance of the interlayer insulation is smaller than the inductance of the coil, the high frequency partial discharge current flows through the capacitance of the interlayer insulation. On the other hand, in the final turn, since the ground insulating capacitance is small, a partial discharge current also flows through the coil inductance. Actually, in Example 1, since c _{r to} 1000 pF, L to 0.1 mH, and c _{g to} 100 pF, the above action is established when the detection frequency region of the partial discharge current is 1 MHz or more. On the other hand, the low-frequency partial discharge current propagates through the coil inductance, but is removed by the high-pass filter 3, so it does not affect the discrimination between the interlayer insulation and the ground insulation partial discharge. As a result, the partial discharge currents detected by the current probes 1 and 61 are as shown in Table 9. As in the case of the first embodiment, it is possible to determine the partial discharge of the interlayer insulation and the ground insulation.

  However, the polarity of the current probe was positive for the current flowing in the direction toward the test phase lead outside the rotating electrical machine, and positive for the direction of the current flowing from the test phase lead to the other phase lead inside the rotary electrical machine. Note that, as described in the operation of the first embodiment, in the present invention, the third implementation is performed in order to determine the partial discharge between the interlayer insulation and the ground insulation of the coil sandwiched between the current probes or the block composed of a plurality of coils. In the form, the detection area is deviated from the first embodiment by a half of the coil. Further, in the third embodiment, as in the first embodiment, the ground insulating partial discharge generating coil can be specified from the polarity of the partial discharge current, and the interlayer insulating partial discharge generating coil can be specified from the difference in current arrival time.

  In the interlayer insulation diagnosis apparatus of the third embodiment, an interlayer short-circuit test can be performed similarly to the first embodiment to identify an interlayer short-circuit coil.

  FIG. 24 shows current characteristics of the interlayer short-circuit coil and the healthy coil. In the healthy coil 201, the current of the current probe increases in proportion to the input current to the coil. In addition, this inclination substantially coincides with the number of turns of the coil. On the other hand, in the interlayer short-circuit coil 200, the current is almost zero even if the current increases. This is because, as shown in FIG. 25B, in the healthy coil 201, n × I current is detected by the current probe linked to the coil. On the other hand, in the interlayer short-circuit coil 200, as shown in FIG. 25A, the current (n−1) × I flowing through the remaining healthy winding portion and the short-circuit current flowing in the direction to cancel the magnetic field generated by the input current ( This is because n-1) I interlinks the current probe in the opposite direction, and the current probe detection current becomes zero.

  Next, an example of performing insulation deterioration diagnosis of a rotating electrical machine using the above-described interlayer insulation diagnosis apparatus and at least updating a coil as necessary will be described. FIG. 26 and FIG. 27 show an example in which the interlayer insulation diagnosis apparatus of the first embodiment is installed to diagnose the interlayer insulation and ground insulation of the induction motor. In this embodiment, UVW three-phase collective power is applied. Moreover, the current probes 1 and 2 were respectively installed in the power line of each phase and the connection part between coils. The outputs of the current probes 1 and 2 are input to the interface device 540, respectively. In the interface device 540, the analog signal is converted into a digital signal by the multi-channel high-speed A / D converter 541, and further, the power frequency component is removed by the built-in digital filter 542, and then transmitted to the computer 510.

The transmitted data is displayed on the partial discharge measurement result screen as shown in FIGS. 6 to 9, and the interlayer insulation and ground insulation partial discharge characteristics for each coil can be examined by operating the function keys. Further, by instructing the [Diagnosis] icon 5312, the amount of discharge charge that must be updated by the coil, for example, ground insulation, is reported by the Central Research Institute of Electric Power Industry “No. With respect to 67001 (1967-4) and interlayer insulation, basically, there is no partial discharge at a shared voltage during operation, and the ground insulation and interlayer insulation partial discharge characteristics of each coil are compared. In the case where a partial discharge generating coil exceeding the standard in ground voltage during operation is found in ground insulation, and a coil in which partial discharge start / extinction voltage is lower than the shared voltage during operation is found in interlayer insulation, the computer 510 As shown in FIG. 27, a warning window 5340 is displayed on the display screen 5300 of the display device 530, and a message 5341 for warning the user is displayed in the window 5340.

  In this case, a characteristic diagram selected by the icon group 5310 is displayed in the characteristic diagram display area 5330. For example, in the example of FIG. 27, a diagram representing FIG. B-1 (interlayer insulation maximum discharge charge amount distribution) is displayed in the left area 5331. Is displayed. Here, the figure schematically shows a state in which the coil is represented by a figure, for example, a square, and the number of squares corresponding to each phase of the UVW is connected by a number, and star-connected. And the display mode of the figure showing the coil which has a problem in an insulation state is changed and displayed. Specifically, for example, highlighting such as thickening the border of a graphic representing a coil, changing the color, or blinking is performed. Further, for each graphic, as with the icon, the pointer MP is placed on the graphic, and the mouse 522 button is clicked to accept selection of the coil represented by the graphic. In response to this, in the right side region 5332 of the characteristic diagram display region 5330, a diagram showing the characteristic of the selected coil, and in the example of FIG. 27, a diagram showing FIG. B-2 (coil maximum discharge charge amount-voltage characteristic) is displayed.

  Note that the ground voltage and interlayer insulation voltage of each coil during operation are stored in the computer in advance by measurement or a value calculated by a circuit calculation program such as EMTP. If the user of the induction motor finds a defective coil and instructs the [Contact] icon 5313, the computer 510 contacts the manufacturer connected via the network. If there is no network, call the phone number displayed in the contact information. Thus, the coil is updated or the induction motor itself is updated.

  By doing so, appropriate operation can be performed without using the induction motor until dielectric breakdown occurs. In particular, in the insulation diagnosis using the interlayer insulation diagnosis apparatus of the present invention, it is possible to find a coil having a problem in interlayer insulation, which has been difficult to find in the past. For this reason, a more reliable induction motor can be provided compared with the past.

  FIG. 28 shows an example of diagnosis of interlayer insulation and ground insulation of an induction motor using an inverter power supply. In this embodiment, the induction motor 223 is connected to an inverter power source 221 connected to an AC power source 220 by a power cable 222. In this embodiment, since the inverter power source used for the operation of the induction motor is directly used, it is not particularly necessary to measure or calculate the ground voltage and the interlayer insulation voltage of each coil during the aforementioned operation. For this reason, insulation diagnosis can be performed in a short time. Moreover, when three-phase alternating current is applied to UVW with an inverter power supply, when the detection current of the current probe installed in each coil of each UVW phase is summed with the same current probe installation position number from the outlet, the power frequency component is The partial discharge can be detected more clearly because they cancel each other.

  Furthermore, in the rotating electrical machine in which the interlayer insulation diagnosis apparatus of the present invention is installed, since the partial discharge can be measured even while the induction motor is operated by the inverter power supply, the deterioration state of the insulating layer can be always grasped. .

  FIG. 29 shows an example of an induction motor whose operation has been stopped because the maximum discharge charge amount for ground insulation has rapidly increased. FIG. 30 shows an example in which a large void is generated in the interlayer insulation due to vibration or thermal degradation, and a partial discharge is suddenly detected. 29 and 30 are the same as those shown in FIGS. 7, 8, 9, 27, and the like.

  Thus, with the interlayer insulation diagnosis device of the present invention, a rotating electrical machine, which has been rarely rapidly deteriorated due to operating conditions or the like in the blank period between periodic diagnoses and has a risk of dielectric breakdown, can be used before dielectric breakdown. The operation can be stopped and the coil can be updated or the rotating electrical machine main body can be updated. As described above, with the interlayer insulation diagnosis apparatus of the present invention, it is possible to perform deterioration diagnosis of the rotating electrical machine interlayer insulation and to provide a rotating electrical machine with higher reliability than the conventional one.

  The above insulation diagnosis system can be summarized as shown in FIG. That is, in this insulation diagnostic system, the interlayer / ground insulation partial discharge measuring unit 112 connected to the rotating electrical machine 118 and the power source 141 capable of switching the type of the power source, the voltage application phase, and the like, and the computer 510 controlling the same are provided. The communication line 111 and the interface device 540 are connected. For example, GP-IB, USB, RS-232C, a communication network, or the like is used as the communication line 111 that transmits and receives commands, data, and the like. As the computer 510 used in the apparatus of FIG. 31, for example, a computer having a hardware system configuration shown in FIG. 37 can be used. The internal functions of the computer 510 realized by executing the program include a processing unit 5110 that performs data processing, a storage unit 5120 that performs data storage processing, and a display and input / output unit 5130 that performs display and input / output control. And a measuring instrument controller 5140 that controls the measuring instrument.

  The external storage device 514 managed by the storage unit 5120 stores data used in diagnosis. An example is shown in FIG. The storage area 5140 of the storage device 514 includes, for example, a data file 5141 including data in the rotating electrical machine interlayer insulation diagnosis device, a user name, a delivery destination, a product model, specifications, a serial number, a manufacturing time, a delivery date, and the like. Data file 5142, drawing data file 5143 including drawing data, data file 5144 having rotating electrical machine voltage distribution data during operation, data file 5145 having ground / interlayer insulation partial discharge characteristic data, and ground / interlayer insulation portion A data file 5146 having discharge reference data is stored.

  In the processing unit 5110, for example, insulation diagnosis is performed in accordance with an insulation diagnosis flowchart of FIG. That is, the partial discharge start voltage Vi, the partial discharge extinction voltage Ve, and the maximum discharge charge amount Qmax are obtained using the results of the interlayer insulation and ground insulation partial discharge measurement (step 2001). Next, it is determined whether Qmax is equal to or greater than the ground insulation reference discharge amount (step 2002). If Qmax is equal to or greater than the ground insulation reference discharge charge amount, it is determined that “the coil or rotating electrical machine should be updated”. Then, a warning message 5341 to that effect is displayed in the warning window 5340 of the display screen 5300 of the display device 530 (step 2004). On the other hand, when Qmax is less than the ground insulation reference discharge charge amount, it is determined whether Vi and Ve are each equal to or lower than the interlayer insulation voltage. If Vi and Ve are each equal to or lower than the interlayer insulation voltage, the process proceeds to step 2004 and the same processing as the above-described coating is performed. If not in phase, it is determined that the inspection has passed (step 2005).

  Next, an example of determining and improving whether or not a used rotating electrical machine manufactured for a commercial frequency power supply or an old inverter power supply can be driven by a new inverter will be described with reference to FIGS. 34 and 35. FIG. In this example, not only the diagnosis apparatus of the present invention but also the rotating electrical machine user 900, the insulation diagnosis company 901, the coil manufacture, the renewal company 902, and the inverter maker 920 are involved. However, there are cases where these parties also serve as each other. The actions performed between the parties can be performed by exchanging various types of information by connecting the computer systems of the parties via a communication line and transmitting and receiving information. Progress management is performed in each computer system according to the exchange of information between the parties.

  In this example, the user 900 requests the inverter manufacturer 920 to introduce a new inverter. In addition, when the new inverter is introduced, the user 900 requests the insulation diagnosis contractor 901 to determine whether or not the used induction motor can be driven by the new inverter. When the insulation diagnosis company 901 uses the interlayer insulation diagnosis apparatus of the present invention using a high frequency voltage as a power supply, the insulation diagnosis supplier 901 inputs the interlayer insulation shared voltage at the time of driving a new inverter obtained by measurement or a circuit calculation program such as EMTP. Measure the partial discharge characteristics of interlayer insulation. However, this operation can be omitted when using a power supply that can output a surge voltage having the same waveform as that of the new inverter, for example, the peak value and the same wavefront length.

  When the interlayer insulation diagnosis apparatus displays a screen that recommends updating of the coil or the rotating electrical machine or a screen that recommends improvement of the inverter waveform as shown in FIG. 27 at the time of diagnosis, the insulation diagnosis contractor 901 displays the result as a user. Report to 900. If necessary, the partial discharge start / extinction voltage is also reported. If a surge power supply is used, the partial discharge start / extinction voltage and wavefront length are also reported. As a result, the user 900 requests the coil manufacturer / updater 902 to manufacture or update the coil, or requests the inverter manufacturer 920 to improve the inverter waveform. When the coil policy / updater 920 receives a request, the coil is updated and then diagnosed again to confirm that a warning screen is not displayed. When the inverter manufacturer receives a request, at least, for example, by increasing the wavefront length 130, reducing the switching voltage 131, or reducing the switching surge voltage 132 as shown in FIG. In the improved waveform, the interlayer insulation voltage is made lower than the interlayer insulation partial discharge start / extinction voltage. As a result, a used rotating electrical machine manufactured for a commercial frequency power supply or an old inverter power supply can be safely operated with the new inverter.

  Note that the partial discharge detection and the diagnosis based on the detected data may be performed by different devices. For example, the system for detecting partial discharge is a formable system that can be brought into the field, and the diagnosis is performed by another computer, for example, a host computer. In the diagnosis, for example, data is accumulated by a system for detecting partial discharge, and the diagnosis can be performed off-line in the host computer. In addition, it is possible to connect to a system walking strike computer that detects partial discharge via a communication line to perform online diagnosis.

  Thus, according to each embodiment described above, insulation diagnosis of a rotating electrical machine can be performed with higher reliability than in the past. As a result, it is possible to present a warning message indicating that the coil or motor needs to be updated as necessary. In particular, a rotating electrical machine with higher reliability can be provided by installing the interlayer insulation diagnosis device of the present invention in a rotating electrical machine, measuring partial discharges even during operation, and performing insulation deterioration diagnosis.

  In addition, by using the above-described diagnostic technique, the interlayer insulation / ground insulation partial discharge characteristic data is compared with the coil rewinding standard, and the coil is changed when the partial discharge charge amount or partial discharge start / extinction voltage does not satisfy the standard. Alternatively, it is possible to realize notification of the necessity of updating the rotating electrical machine and improving the inverter waveform. Furthermore, it is possible to determine whether a used rotating electrical machine manufactured for a commercial frequency power supply or an old inverter power supply can be driven by a new inverter, using the above-described diagnostic technique. As a result, by improving the renewal of the coil of the rotating electrical machine and improving the waveform of the inverter, it can be used for safer operation.

  In addition, the above system compares the interlayer insulation partial discharge characteristics data with the interlayer insulation voltage when the inverter surge is applied, and at least the shared voltage is higher than the partial discharge start or extinction voltage, or the partial discharge characteristics and residual breakdown When it is judged that the interlayer insulation has deteriorated to the extent that it cannot withstand future operation due to the voltage relationship, it can be realized by a system that notifies that the coil or rotating electrical machine needs to be updated or the inverter waveform needs to be improved .

  As described above, the diagnosis device of the present invention can measure the partial discharge characteristics of the interlayer insulation and perform the deterioration diagnosis of the rotating electrical machine interlayer insulation, thereby providing a highly reliable rotating electrical machine. . Further, the diagnostic device of the present invention can determine whether a used rotating electrical machine manufactured for a commercial frequency power supply or an old inverter power supply can be driven by a new inverter. And if necessary, it is possible to make improvements. As a result, a highly reliable rotary electric machine that can be driven safely and an inverter power supply can be realized.

FIG. 1 is a block diagram showing a configuration of an interlayer insulation diagnosis apparatus according to the first embodiment of the present invention. FIG. 2 is a circuit diagram showing a ladder-type equivalent circuit model of the induction motor coil and a partial discharge current path of interlayer insulation and ground insulation in the interlayer insulation diagnostic device of the first embodiment. FIG. 3 is an explanatory diagram showing an operation of discriminating a partial discharge current waveform detected by a current probe by a logic discrimination circuit. FIG. 4 is a block diagram showing an example of the configuration of a logic discriminator that can be used in the present invention. FIG. 5A is a graph showing a delay in rising of a current pulse accompanying a delay in arrival time of an interlayer insulating partial discharge current, and FIG. 5B is an explanatory diagram showing a positional relationship between a coil and a current probe. FIG. 6 is an explanatory view showing an example of a display screen showing a rotating electrical machine coil voltage distribution and a maximum discharge charge amount-voltage characteristic. FIG. 7 is an explanatory diagram showing an example of a display screen showing the distribution of the maximum electric discharge amount of the rotating electrical machine coil and the maximum discharge charge amount-voltage characteristic. FIG. 8 is an explanatory diagram illustrating an example of a display screen of a rotating electrical machine coil maximum discharge charge amount distribution, discharge occurrence frequency-discharge charge amount characteristic. FIG. 9 is an explanatory diagram illustrating an example of a rotating electrical machine coil discharge frequency distribution and a discharge frequency-voltage characteristic display screen. FIG. 10 is a flowchart for identifying a partial discharge generating coil by changing the current probe position while reducing the number of coils one by one from the partial discharge measurement phase lead and the non-partial discharge measurement phase lead. FIG. 11 is a flowchart for identifying a partial discharge generating coil by changing the current probe position while dividing the current probe position into two from the partial discharge measurement phase lead and the non-partial discharge measurement phase lead. FIG. 12A is a graph showing the change of the coil ground voltage with respect to the coil number from the lead when the power supply frequency is changed, and FIG. 12B shows the change of the coil sharing voltage with respect to the coil number from the lead when the power supply frequency is changed. Graph. FIG. 13A is a circuit diagram showing a circuit configuration for reducing the current capacity of the power supply by putting an inductive load in parallel with the rotating electric machine and the coupling capacitor, and resonating in parallel, and FIG. 13B shows an inductive load in series. The circuit diagram which shows the circuit structure which reduces the output voltage of a power supply by putting in and making it series-resonate. FIG. 14A is a waveform diagram showing a power capacity reduction method using intermittent sine wave pulses, and FIG. 14B is a waveform chart showing a power capacity reduction method using attenuation waveforms. FIG. 15 is a graph showing the relationship between the current probe detection current of the interlayer short-circuit coil and the healthy coil and the coil sharing voltage. FIG. 16A is an explanatory diagram showing an equivalent circuit of an interlayer short circuit coil, and FIG. 16B is an explanatory diagram showing an equivalent circuit of a sound coil. FIG. 17 is a block diagram showing a configuration of an interlayer insulation diagnosis apparatus according to the second embodiment of the present invention. FIG. 18 is a circuit diagram showing a ladder-type equivalent circuit model of an induction motor coil and a partial discharge current path of interlayer insulation and ground insulation in the diagnostic device of the second embodiment. FIG. 19 is a flowchart for specifying an interlayer insulation partial discharge and an end discharge generation unit by changing the current probe position while reducing the number of coils one by one from the partial discharge measurement phase lead and the non-partial discharge measurement phase lead. FIG. 20 is a waveform diagram showing the relationship between the phase of the ground voltage and the ground insulating partial discharge polarity. FIG. 21 is a block diagram showing a configuration of a logic discriminator that distinguishes between partial insulation of interlayer insulation and ground insulation from the phase of the ground voltage and the polarity of the discharge current of the current probe 2. FIG. 22 is a block diagram showing a configuration of an interlayer insulation diagnosis apparatus according to the third embodiment of the present invention. FIG. 23 is a circuit diagram showing a detailed equivalent circuit model of the induction motor and a partial discharge current path of interlayer insulation and ground insulation in the diagnostic apparatus of the third embodiment. FIG. 24 is a graph showing the relationship between the coil input current of the interlayer short-circuit coil and the healthy coil and the current probe detection current. FIG. 25A is an explanatory diagram showing that the current probe detection current of the interlayer short-circuit coil becomes 0, and FIG. 25B is an explanatory diagram showing an equivalent circuit of the healthy coil. FIG. 26 is a wiring diagram showing an example of an insulation diagnosis of an induction motor using a high-frequency voltage. FIG. 27 is an explanatory diagram showing an example of a display screen when a defect in interlayer insulation is found during insulation diagnosis. FIG. 28 is an explanatory diagram showing an example of the position of an inverter-driven rotating electrical machine in which an interlayer insulation diagnosis device is installed. FIG. 29 is an explanatory diagram showing an example of a display screen when a rotating electrical machine in which the ground insulating partial discharge charge amount suddenly increases is detected by measuring partial discharge even during inverter operation. FIG. 30 shows an example in which a rotating electric machine in which partial discharge has suddenly occurred from interlayer insulation due to a malfunction is detected by measuring partial discharge even during inverter operation. FIG. 31 is a block diagram illustrating a configuration example of a simplified insulation diagnosis system. FIG. 32 is a flowchart showing the procedure of insulation diagnosis. FIG. 33 is an explanatory diagram showing an example of the position of the data file of the insulation diagnosis system. FIG. 34 is an explanatory diagram showing a procedure for taking measures against driving a used rotating machine by an inverter. FIG. 35 is an explanatory diagram showing a procedure for taking measures to improve the waveform of the inverter that drives the rotating machine. FIG. 36 is a waveform diagram showing a waveform for improving the waveform of the inverter that drives the rotating machine. FIG. 37 is a block diagram showing an example of a hardware system configuration of an information processing system used for processing for detecting and diagnosing partial discharge in the present invention. FIG. 38 is a partially cutaway side view showing the structure of the rotating electrical machine. FIG. 39A is a perspective view showing a structure of a coil of a rotating electrical machine, and FIG. 39B is a cross-sectional view taken along line AA ′.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current probe installed in coupling capacitor 2 Current probe installed in connection between first coil and second coil 3 Multi-channel high-pass filter 4 Logic discriminator 5 Discharge measuring instrument 6 Coupling capacitor 7 Test power supply 8 Test Power supply internal impedance, protective resistance, blocking impedance 9 Power line 10 Induction motor 11 U-phase first coil 12 U-phase second coil 13 V-phase or W-phase first coil 14 U-phase first coil-second coil connection part 15 U-phase second coil-third coil connection 16 Rotating electrical machine coil end coil connection side 17 Rotating electrical machine coil end coil non-connection side 20 Interlayer insulation partial discharge 21 Ground insulation partial discharge 22 Interlayer insulation partial discharge current 23 Ground insulation partial discharge current 24 Partial discharge current 25 detected by current probe 1 Detected by current probe 2 Partial discharge current 26 Output signal of logic discriminator 27 Test phase lead 28 Other phase lead 30 Rotating electric machine and coupling capacitor 31 Coil 40 Electrode 41 installed on insulating layer surface of connection part between coils Coil to ground voltage measuring capacitor 42 Coil Insulating layer capacitance of the connecting portion 50 Coil to ground voltage 51 Ground insulating partial discharge pulse train example 60 Coil end opposite coil end portion 61 Current probe installed on the opposite coil end portion of the lead wire Rotating electrical machine coil 100 Rotating electrical machine user DESCRIPTION OF SYMBOLS 101 Insulation diagnosis supplier 102 Coil manufacture, renewal supplier 111 Command / data communication line 112 Interlayer / Ground insulation partial discharge measuring part 118 Rotating electrical machine 120 Inverter manufacturer 130 Wave head length 131 Switching voltage 132 Switching surge voltage 140 Insulation diagnostic device 141 Power supply 161 Coil mouth And (input)
162 Coil opening (out)
163 Ground electrode 170 Interlayer insulation 171 Coil conductor 172 Coil conductor bundle 173 Ground insulation 180 Rotating machine 181 Stator 182 Rotor 183 Stator slot 190 Comparator 191 Exclusive OR circuit 192 Inversion circuit 193 Interlayer insulation, ground insulation partial discharge changeover switch 194 Gate Switch 200 Interlayer short circuit coil 201 Sound coil 210 Comparator 211 Delay circuit 212 Exclusive OR circuit 213 Interlayer insulation, ground insulation partial discharge changeover switch 214 Gate switch 215 Inversion circuit 220 AC power supply 221 Inverter power supply 222 Power cable 223 Induction motor 230 Interlayer insulation partial discharge Generator coil 231 Current probe 232 located between the inter-coil connections on the power source side at the inter-coil connection at both ends of the inter-layer insulation partial discharge generator coil In the connection part between the coils at both ends of the electricity generating coil, the current probe 233 located in the connection part between the coils on the neutral point side. In the connection part between the coils separated from the interlayer insulation partial discharge generation coil, the connection between the coils on the power source side. Current probe 234 located in the middle part In the inter-coil connection part one away from the interlayer insulation partial discharge generating coil, the current probe 235 located in the inter-coil connection part on the neutral point side is separated by two from the interlayer insulation partial discharge generation coil In the inter-coil connection portion, the current probe 236 located in the inter-coil connection portion on the power supply side In the inter-coil connection portion two away from the interlayer insulation partial discharge generating coil, the current probe located in the inter-coil connection portion on the neutral point side 500 Information Processing System 510 Computer 530 Display Device 540 Interface Device

Claims (4)

In rotating electrical machines with multiple coils,
A rotating electrical machine characterized in that an inter-coil connecting portion conductor for connecting a coil and a ground are capacitively coupled, and a discharge current sensor is installed in the capacitively coupled portion. In the rotating electrical machine according to claim 1,
A rotating electrical machine characterized in that when a neutral point is grounded, a discharge current sensor is installed on a neutral point grounding wire at a connection portion between coils corresponding to the neutral point. The rotating electrical machine according to any one of claims 1 and 2,
The rotating electrical machine according to claim 1, wherein a current probe, a Rogowski coil, a high frequency CT, and a resistor are used as the discharge current sensor. In the coil applied voltage measuring method of the rotating electrical machine,
The rotating electric machine is characterized in that it measures the voltage generated in the capacitive or resistive voltage divider at the lead-out portion and the voltage generated in the capacitor of the capacitive coupling portion between the coils at the connection portion between the coils. Coil applied voltage measurement method.

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