JP5101213B2 - Turbine generator - Google Patents

Description

The present invention relates to a turbine generator, in particular, it relates to a turbine generator capable of suppressing the vibration caused by the electromagnetic force of the stator winding end which projects from the stator core.

  In order to suppress vibration due to electromagnetic force at the stator winding end, a conventional turbine generator, as shown in Patent Document 1, is a so-called passive vibration suppressing structure in which the stator winding end is fixed by a support structure. Met.

JP 2000-245095 A

  In the case of the passive vibration suppression structure as described above, the operating frequency of the turbine generator and the natural frequency of the stator winding end are close to each other, or an excitation force such as electromagnetic force at the stator winding end. When the vibration response is large, the natural frequency at the end of the stator winding is close to the operating frequency due to the load fluctuation of the turbine generator, that is, the temperature change of the stator winding accompanying the change in the output current of the turbine generator. In this situation, the stator winding end vibrates, and this vibration causes the insulation layer at the stator winding end to crack or break due to abnormal wear or fatigue at the contact part with the support structure. There is.

An object of the present invention is to provide a turbine generator capable of preventing cracks and breakage of an insulating layer by suppressing vibrations at the end of a stator winding.

To achieve the above object, the present invention provides a vibration detector for detecting vibration of a stator winding end protruding from a stator core, and a stator winding end based on a detection signal from the vibration detector. The means for changing the vibration responsiveness of the stator winding end is a means for controlling the rigidity of the stator winding, and the means for controlling the rigidity is the stator. It is a means for controlling the temperature of the winding, and the means for controlling the temperature is a means for controlling the temperature and flow rate of a cooling medium for directly or indirectly cooling the stator winding.

  By providing a means for changing the vibration responsiveness of the stator winding end according to the operating situation in this way, the vibration response of the stator winding end can be suppressed and the natural vibration can be changed. Proximity to the operating frequency of the turbine generator can be avoided, and as a result, vibration at the end of the stator winding can be suppressed to prevent cracking and destruction of the insulating layer.

As described above, according to the present invention, it is possible to obtain a turbine generator capable of suppressing the vibration of the end portion of the stator winding and preventing the insulating layer from cracking or breaking.

  The present invention pays attention to the fact that the vibration of the machine is related to the rigidity (Young's modulus) of the target part, and this rigidity changes with temperature. By changing the rigidity appropriately, the vibration response of the target part is changed. It suppresses vibration.

  Hereinafter, a first embodiment of a turbine generator according to the present invention will be described with reference to FIGS.

The turbine generator includes a stator having a stator core 1 and a stator winding 2 mounted in a winding groove formed in the stator core 1, and a fixed overhanging from the stator core 1. The child winding end 3 is mechanically supported by a support structure such as an annular support member 4 or a plate-like support member 5 fixed to the end of the stator core 1. A rotor (not shown) that is driven by a driving machine such as a gas turbine or a steam turbine is incorporated on the inner peripheral side of the stator configured as described above. Such a turbine generator is covered with a sealed turbine casing 6.

  The stator winding 2 is arranged by combining a plurality of hollow wire conductors 8 with wire insulation and solid wire conductors 9 with wire insulation, and a main insulating layer 10 on the outer periphery. Is given.

  A liquid refrigerant such as water or oil is supplied to the hollow wire conductor 8 of the stator winding 2 configured in this way from a refrigerant supply device 11 installed outside the turbine casing 6 and circulated to make the stator winding. Temperature rise during operation of line 2 is suppressed. Therefore, the present embodiment is a direct cooling type turbine generator that directly cools the stator winding 2.

  In the turbine generator configured as described above, the vibration detector 12 includes the vibration sensor 12 fixed to the stator winding end 3 and the vibration signal transmitter 13 that receives the detection signal from the vibration sensor 12 and transmits the vibration signal. The vibration signal from the vibration signal transmission device 13 is sent to the operation control device 14 that controls the operation of the turbine generator, and the amount of refrigerant supplied from the refrigerant supply device 11 according to the magnitude of the vibration. And the refrigerant temperature is adjusted. In addition, the operation control device 14 is configured to receive a signal from the signal transmission device 15 of the generator load information that transmits an information signal of a change in output current that is a load change of the generator.

  With the above-described configuration, when the load during the operation of the turbine generator fluctuates and the vibration of the stator winding end 3 increases, the vibration is detected by the vibration sensor 12, and the vibration signal transmission device 13, the signal is input to the operation control device 14 and the signal from the signal transmission device 15 of the generator load information is input.

  Then, as shown in the flowchart shown in FIG. 5, when the operation control device 14 determines that the vibration is increased due to an increase in load, the amount of liquid refrigerant supplied to the stator winding 2 is changed. An instruction to increase or decrease the refrigerant temperature is output to the refrigerant supply device 11. As the temperature of the stator winding 2 decreases due to an increase in the amount of refrigerant supplied or a decrease in the refrigerant temperature, the Young's modulus of the stator winding 2 increases, thereby increasing the rigidity of the stator winding end 3. As a result, the vibration responsiveness can be lowered with respect to the operating excitation frequency of the stator winding end 3 and the vibration of the stator winding end 3 can be reduced.

  On the other hand, if the operation control device 14 determines that the vibration is increased due to a decrease in the load, the amount of liquid refrigerant supplied to the stator winding 2 is reduced or the refrigerant temperature is increased. An instruction is output to the refrigerant supply device 11. As the temperature of the stator winding 2 increases due to a decrease in the refrigerant supply amount or an increase in the refrigerant temperature, the Young's modulus of the stator winding 2 decreases, and thereby the rigidity of the stator winding end 3 decreases. As a result, the vibration responsiveness can be lowered with respect to the operating excitation frequency of the stator winding end 3 and the vibration of the stator winding end 3 can be reduced.

  Further, when the vibration of the stator winding end 3 by the vibration sensor 12 does not change or decreases, the operation control device 14 does not refer to the signal of the signal transmission device 15 of the generator load information and supplies the refrigerant. The apparatus 11 is continuously instructed to maintain the current amount of refrigerant or refrigerant temperature.

  As described above, according to the present embodiment, the vibration responsiveness of the stator winding end 3 can be changed according to the operating state, and the vibration sensor 12 can be used for long-term operation of the stator winding end 3. Even when it is detected that the vibration characteristic has changed, it is possible to actively suppress the vibration and prevent the insulating layer of the stator winding end 3 from being cracked or broken.

  By the way, in order to detect the vibration of the stator winding end 3, the vibration sensor 12 is preferably provided with a sensor for detecting radial vibration, circumferential vibration, and combined vibration in both radial and circumferential directions. Of course, three vibration sensors may be selectively installed according to the purpose. Furthermore, since the stator winding end 3 is at a high voltage and a high electric field during operation, the vibration sensor 12 is an electric vibration meter such as an optical vibration meter in which the detected vibration signal is optically transmitted through an optical fiber. It is desirable that the vibration sensor be insulated.

  Here, in the present embodiment, the means for changing the vibration responsiveness of the end portion of the stator winding according to the present invention in accordance with the operation status is the refrigerant supply device 11, the vibration sensor 12, the vibration signal transmission device 13, and the operation. The control device 14 and the generator load information signal transmission device 15, the vibration detectors are the vibration sensor 12 and the vibration signal transmission device 13, and means for changing the vibration responsiveness at the end of the stator winding. The refrigerant supply device 11 and the operation control device 14 are means for controlling the rigidity of the stator winding, means for controlling the temperature of the stator winding, and means for controlling the temperature and flow rate of the cooling medium. The device 11 and the operation control device 14.

  FIG. 6 shows a second embodiment of the turbine generator according to the present invention, and the same reference numerals as those in the first embodiment denote the same components, and thus detailed description thereof is omitted.

  The configuration of the present embodiment is almost the same as that of the first embodiment. The configuration different from that of the first embodiment is that a refrigerant cooling device 16 is installed in the turbine casing 6, the refrigerant is circulated from the refrigerant supply device 11 to the refrigerant cooling device 16, the air in the turbine casing 6, etc. After the gaseous refrigerant is cooled by the refrigerant cooling device 16, as indicated by an arrow a, it is forcedly circulated to the rotor and the stator by a blower 17 such as a blower, and the stator winding 2 is inside the hollow wire conductor 8. It is a point which cools by making it distribute | circulate to.

  Even with the above configuration, it is possible to obtain the same effect by judging the vibration state of the stator winding end 3 and suppressing the vibration of the stator winding end 3 in the same manner as in the first embodiment. Can do.

  FIGS. 7 and 8 show a third embodiment of a turbine generator according to the present invention. The same reference numerals as those in the first and second embodiments denote the same components. Is omitted.

  This embodiment has basically the same configuration as that of the second embodiment. The configuration different from the second embodiment is the configuration of the stator winding 2 and the accompanying stator winding 2. This is a cooling configuration. That is, the stator winding 2 is a hollow wire conductor in which only a plurality of solid wire conductors 9 subjected to wire insulation are arranged and the outer periphery thereof is covered with a main insulating layer 10 to circulate refrigerant. Is not used.

  Therefore, as in the second embodiment, a refrigerant such as air in the turbine casing 6 is passed through the refrigerant cooling device 16 to which the refrigerant is supplied by the blower 17 to cool it, and the cooled gaseous medium is Forcibly circulates through the rotor and stator, and the stator winding end 3 is indirectly contacted with a gaseous refrigerant on the surface of the main insulating layer 10 as shown by an arrow a as shown in FIG. I'm trying to cool it down. Therefore, the present embodiment is an indirect cooling type turbine generator that indirectly cools the stator winding end 3.

  Even with the above configuration, the vibration state of the stator winding end 3 is determined and the vibration suppression of the stator winding end 3 is performed in the same manner as in the second embodiment, thereby providing substantially the same effect. be able to.

  In the above explanation, the temperature of the stator winding 2 is changed based on the vibration of the stator winding end 3 and the generator load information, and thereby the rigidity (Young's modulus) of the stator winding end 3 is changed. In the fourth embodiment shown in FIG. 9, the stator winding is changed based on vibration characteristic data acquired in advance. 2 is controlled to change the rigidity (Young's modulus) of the stator winding end 3.

That is, after the design process or completion of the turbine generator, the vibration response (sensitivity) of the stator winding end 3, in other words, the transfer function is obtained and the modal analysis of the vibration is performed, and the stator winding end If basic vibration data such as ring group vibration characteristic data and system vibration characteristic data is acquired in advance, the vibration responsiveness of the operating frequency component that is harmful at the operating temperature of the stator winding end 3 ( Sensitivity) can be estimated. The vibration responsiveness (sensitivity) can be increased or decreased by adjusting the temperature of the stator winding end 3 by adjusting the temperature of the driving excitation frequency.

  Therefore, assuming the operating load condition of the turbine generator in advance, the temperature of the refrigerant is set so that the vibration response (sensitivity) at the operating load is lower at the operating excitation frequency. Repression is achieved.

  Specifically, according to the flowchart of FIG. 9, first, basic data of the vibration of the stator winding end is acquired by modal analysis, and then input to the storage unit of the operation control device 14 during actual operation. The acquired data and basic data are compared and analyzed by the calculation unit. When the natural frequency (Fn) at the end of the stator winding during operation is more than 5% deviated from the operation double frequency, the flow rate and the refrigerant temperature are set in the refrigerant supply device 11 in advance. Give instructions to continue driving. However, when the natural frequency (Fn) of the stator winding end is close to the operation double frequency, that is, close to less than 5%, the operation control device 14 supplies the refrigerant supply device 11 with a flow rate or a refrigerant. An instruction is given to increase or decrease the amount of refrigerant set in advance, or to shift to higher or lower refrigerant temperature.

  In this way, vibration response can be changed by controlling the temperature of the stator winding end based on the basic data of vibration that has been obtained in advance, and the same effect as in the above embodiment can be obtained. .

  In the present embodiment, the storage unit storing the vibration characteristic data analyzed in advance according to the present invention is a storage unit of the operation control device 14, and the detection signal from the vibration detector and the vibration characteristic data of the data storage unit. Is a calculation unit of the operation control device 14.

  By the way, in the present embodiment, the data acquired in advance is compared with the data acquired during operation, and when there is a difference between the two data, the vibration responsiveness is changed. When the operation condition of the turbine generator does not always change, the operation control device 14 is programmed with a timing for changing the vibration responsiveness based on the data acquired in advance, and the vibration responsiveness depends on the programming. May be changed.

Next, a reference example of a turbine generator , which is a reference example similar to a part of the concept of the present invention , will be described with reference to FIGS. Note that the same reference numerals as those in FIG.

  The difference in appearance from FIG. 2 of the first embodiment is that a weight 18 is provided at the stator winding end 3 to suppress vibration of the stator winding end 3.

  That is, in the design process or after completion of the turbine generator, the vibration response sensitivity of the stator winding end 3, in other words, the transfer function is obtained and the modal analysis of the vibration is performed, and the stator winding end group Estimating the vibration response sensitivity of harmful operating frequency components at the operating temperature of the stator winding end 3 if basic vibration data such as ring vibration characteristic data and system vibration characteristic data is acquired in advance. As described above, this can be done.

On the other hand, the general relationship between the natural frequency f0, the stiffness (Young's modulus) E, and the mass M is expressed by Equation 1, indicating that the natural frequency f0 can be changed by changing the stiffness E and the mass M.
f0 = 1 / 2π√ (E / M) Equation 1
The vibration responsiveness of the driving excitation frequency can be changed by adjusting the natural frequency f0. That is, by changing the natural frequency f0 at the target portion of the stator winding end 3, the vibration response (sensitivity) with respect to the operating excitation frequency can be increased or decreased.

  FIG. 11 illustrates an example of adjusting the response sensitivity at the driving excitation frequency f1 by adjusting the natural frequency f0. First, assuming the operating load state of the turbine generator in advance, as shown in FIG. 11A, when the natural frequency f0 of the stator winding end 3 exists in the vicinity of the operating excitation frequency f1, The vibration characteristic S0 is changed by changing the rigidity E or the mass M of the equation 1 so that the vibration response sensitivity L1 at the driving load becomes a lower value at the driving excitation frequency f1. For example, as shown in FIG. 11B, by changing the stiffness E and the mass M and changing the vibration characteristic S1 in a direction in which the natural frequency f0 of the stator winding end 3 is increased, the operating excitation frequency f1 is changed. As shown by the white arrow, the vibration response sensitivity L2 at has a low value, and resonance with the driving excitation frequency f1 can be avoided.

  In this example, the stiffness E or the mass M is changed so that the natural frequency f0 increases in the direction of increasing with respect to the operating excitation frequency f1, but the natural frequency f0 is lower than the operating excitation frequency f1. You may make it change in the direction which becomes.

By the way, changing the rigidity E of Formula 1 is the first to fourth embodiments, and changing the mass M is the reference example .

  An example of adjusting the vibration response sensitivity when the weight 18 of the stator winding end 3 is loaded will be described with reference to FIG.

  The weight 18 is a small piece having a curvature along the outer peripheral surface of the annular support member 4, and one or a plurality of weights 18 of the small pieces are fixed to the outer peripheral surface of the annular support member 4. As for the fixing method, fixing is performed using a well-known string binding means or a fastening means using screws. With the addition of the weight 18, the weight (mass) of the system of the stator winding end 3 increases, and accordingly, the vibration characteristic S0 changes in the direction of decreasing as the vibration characteristic S2. Then, the natural frequency f0 also changes and decreases so as to be lower than the driving vibration frequency f1, and as a result, the vibration response sensitivity L1 at the driving vibration frequency f1 is low as indicated by a white arrow like L2. Thus, resonance with the operating excitation frequency f1 can be avoided.

By the way, as shown in Equation 2, which is the basis of the equation of motion when the exciting force is F, the weight is m, and the acceleration is a, the system becomes heavier under the condition that the exciting force F is constant and the weight m becomes smaller. When increased, there is an effect of reducing the acceleration a. Therefore, when the amplitude is A, the acceleration is a, and each frequency is ω, the effect of suppressing the amplitude A, that is, the vibration response sensitivity, as shown in Expression 3. This also has the effect of reducing L, and the vibration of the stator winding end 3 is reduced.
F = ma ... Formula 2
a = Aω2 Equation 3
Note that the change in the natural frequency f0 and the change in the vibration response sensitivity L in FIG. 12 are visual concepts of Expressions 1 and 2, and are not phenomena that occur individually.

  By the way, since the weight 18 is more effective in adjusting the vibration response sensitivity L, it is desirable to use an iron-based metal material or a nonmagnetic metal.

The block diagram which shows 1st Embodiment of the turbine generator by this invention. FIG. 2 is a longitudinal perspective view showing a stator winding end including the stator core of FIG. 1. The perspective view which shows the stator coil | winding edge part of FIG. FIG. 2 is a longitudinal enlarged view of the stator winding of FIG. 1. The flowchart figure which shows the vibration suppression method of the stator coil | winding edge part of the turbine generator of FIG. The block diagram which shows 2nd Embodiment of the turbine generator by this invention. The block diagram which shows 3rd Embodiment of the turbine generator by this invention. FIG. 8 is a longitudinal enlarged view of the stator winding of FIG. 7. The flowchart figure which shows the vibration suppression method of the stator coil | winding edge part of the turbine generator of FIG. FIG. 2 is a view corresponding to FIG. 2 showing a turbine generator according to a reference example of the present invention. The diagram which shows an example of the adjustment method of the vibration response sensitivity of a stator coil | winding edge part. The diagram which shows an example of the adjustment method of the vibration response sensitivity of the stator winding | coil by FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Stator iron core, 2 ... Stator winding, 3 ... Stator winding edge part, 4 ... Ring support member, 5 ... Plate support member, 6 ... Turbine casing, 8 ... Hollow strand conductor, 9 ... Medium Real wire conductor, 10 ... main insulation layer, 11 refrigerant supply device, 12 ... vibration sensor, 13 ... vibration signal transmission device, 14 ... operation control device, 15 ... signal transmission device, 16 ... refrigerant cooling device, 17 ... blower, 18 ... Weight.

Claims (1)

A vibration detector for detecting the vibration of the stator winding end protruding from the stator core, and means for changing the vibration responsiveness of the stator winding end based on a detection signal from the vibration detector; Prepared,
The means for changing the vibration responsiveness of the stator winding end is a means for controlling the rigidity of the stator winding,
The means for controlling the rigidity is a means for controlling the temperature of the stator winding,
Means, characteristics and to filter turbine generator to be a means for controlling the temperature and flow rate of the cooling medium to be directly or indirectly cooled stator winding for controlling the temperature.

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