JP2014194173A - Motor malfunction detection method, motor control device performing the same, and power-generation plant including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce error detection of a motor malfunction.SOLUTION: A control device 100 includes a malfunction determination part 160 and a correction part 150. The malfunction determination part 160 determines whether a gas turbine 10 as a motor is malfunctioning according to whether a fluctuation range of output of a generator 20 detected by an output meter 26 is beyond an allowable output fluctuation range. The correction part 150 corrects the allowable output fluctuation range by using the number of revolutions detected by a revolution counter 25 so that the allowable output fluctuation range increases with increasing fluctuation range of the number of revolutions.

Description

  The present invention relates to an abnormality detection method for a prime mover mechanically connected to a generator, a control device for the prime mover that executes the method, and a power plant including the control device.

  Examples of the prime mover mechanically connected to the generator include a gas turbine, a steam turbine, and a windmill. If a sudden output change of these prime movers, that is, fluctuations can be detected, safe operation of the prime mover can be realized.

  Therefore, in Patent Document 1, an output change amount or an output change rate that is a difference between the current output of the prime mover or the generator and the output of the prime mover or the generator before a predetermined time is obtained, and these values and the reference value are obtained. By comparing, we have proposed a technology that detects sudden changes in the output of the prime mover.

JP-A-11-64127

  The output of the generator is basically equal to the output of a prime mover such as a gas turbine or a steam turbine. For this reason, if one output can be detected among a motor | power_engine and a generator, this can be handled as the other output.

  By the way, it is difficult to directly detect the output of the prime mover. On the other hand, regarding the output of the generator, this output can be easily detected by providing an output meter (wattmeter) in the generator. For this reason, when detecting the output of a motor | power_engine or a generator, the output of a generator is detected and this is often substituted.

  Thus, when an output meter is provided in the generator and the output of the generator and the prime mover is managed, even if the output of the prime mover is constant, the rotation speed of the generator and the generator The output fluctuates. Generally, a prime mover such as a gas turbine or a steam turbine is provided with a function of detecting a load change and causing a trip when the change is abrupt. In such a case, the technique described in Patent Document 1 may detect that the output of the prime mover has suddenly changed even if the output of the prime mover is constant, and trip the prime mover for safe operation of the prime mover. Is expensive.

  In other words, the conventional technique has a problem that when the power system fluctuates, it may be erroneously detected that the prime mover is abnormal.

  Accordingly, an object of the present invention is to provide a prime mover abnormality detection method capable of reducing erroneous detection of a prime mover abnormality, a prime mover control apparatus that executes these methods, and a power plant including the apparatus. To do.

A method for detecting an abnormality of a prime mover as one aspect according to the invention for achieving the above object is as follows:
In the abnormality detection method for the prime mover mechanically connected to the generator, the prime mover depends on whether or not the fluctuation range of the output of the generator detected by the output meter is outside the range of the allowable output fluctuation range. An abnormality determination step for determining whether or not is abnormal, the allowable output fluctuation range that is a determination criterion in the abnormality determination step, and the output meter that is detected in the abnormality determination step And a correction step of correcting one of the outputs using the rotation speed of one of the generator and the prime mover detected by a tachometer.

  Even when the output of the prime mover is constant, if the power system fluctuates, the rotational speed of the generator and the output of the generator fluctuate accordingly. In this case, in the abnormality detection method, using the number of rotations, an allowable output fluctuation range that is a determination criterion in the abnormality determination step and an output detected by the output meter that is a determination target in the abnormality determination step One is corrected. Therefore, in this abnormality detection method, even if the output of the generator fluctuates due to fluctuations in the rotation speed of the generator accompanying fluctuations in the power system, the fluctuations in the power system Is treated as having no output fluctuation.

  Therefore, in the abnormality detection method, it is possible to reduce erroneous detection of a motor abnormality when the power system fluctuates.

  Here, in the abnormality detection method for the prime mover, in the correction step, a rotation speed fluctuation calculation step for obtaining a rotation speed fluctuation width of the rotation speed using the one rotation speed, and the rotation speed fluctuation width is large. Accordingly, an allowable fluctuation range correction step for correcting the allowable output fluctuation range so as to increase the allowable output fluctuation range is executed, and in the abnormality determination step, the output detected by the output meter is detected. Whether or not the prime mover is abnormal may be determined according to whether or not the fluctuation range is outside the range of the allowable output fluctuation range corrected in the correction step.

  In the abnormality detection method, the allowable output fluctuation range increases as the rotational speed fluctuation range increases. For this reason, in this abnormality detection method, even if the output of the generator fluctuates due to fluctuations in the number of revolutions of the generator accompanying fluctuations in the power system, the allowable output fluctuation range increases, so that erroneous detection of motor abnormality is reduced. can do.

  Further, in the prime mover abnormality detection method for executing the permissible fluctuation range correction step, in the rotation speed fluctuation range calculation step, when the rotation speed is lower than a rated rotation speed, the prime mover and the power generation An upper reference rotational speed calculation step for obtaining a reference rotational speed, which is a rotational speed obtained using a rotational speed reduction rate allowed when the machine is operating normally, and when the rotational speed is equal to or lower than a rated rotational speed The lower reference rotational speed, which is the rotational speed obtained using the rotational speed increase rate allowed when the prime mover and the generator are in normal operation when increased, the same as the upper reference rotational speed A lower reference rotational speed calculating step for obtaining a lower reference rotational speed at a time, and a deviation calculating step for obtaining a difference between the upper reference rotational speed and the lower reference rotational speed and outputting the difference as the rotational speed fluctuation range. May run

  Further, in any of the prime mover abnormality detection methods for executing the allowable fluctuation range correction step, in the abnormality determination step, a difference between the output detected by the output meter and a reference output with respect to the output is calculated. You may perform the output fluctuation | variation calculation process made into fluctuation | variation.

  Moreover, in the abnormality detection method for the prime mover as the one aspect, in the correction step, the one rotational speed, a rotational speed change rate that is a change rate per unit time of the rotational speed, the prime mover, and the power generation Using the moment of inertia of the rotating system in the machine, the apparent output fluctuation of the prime mover is obtained, and the value obtained by subtracting the apparent output fluctuation from the output of the generator detected by the output meter is corrected. In the abnormality determination step, whether or not the prime mover is abnormal depending on whether or not the fluctuation range of the output corrected in the correction step is outside the range of the allowable output fluctuation range. May be judged.

  As described above, even when the output of the prime mover is constant, if the power system changes, the rotational speed of the generator and the output of the generator change accordingly. The output fluctuation of the generator in this case becomes an apparent output fluctuation for the prime mover. Therefore, in the abnormality detection method, the apparent output fluctuation of the prime mover is obtained using the rotational speed, etc., and the apparent output fluctuation is subtracted from the output detected by the output meter, and the output detected by the output meter is detected. The fluctuations in output due to fluctuations in the power system are excluded. For this reason, in this abnormality detection method, even if the output of the generator fluctuates due to fluctuations in the number of rotations of the generator accompanying fluctuations in the power system, the abnormality of the prime mover is determined based on the output from which this fluctuation in output is removed. Therefore, it is possible to reduce the erroneous detection of the engine abnormality.

  Here, in the abnormality detection method for the prime mover for obtaining an apparent output fluctuation of the prime mover, in the correction step, an output from the output meter with respect to an output from the speed meter from the output outputted from the output meter. It is preferable to subtract the apparent output fluctuation that is delayed by the delay time.

  As a result of comparing the phase of the rotation speed detected by the tachometer and the phase of the actual output detected by the power meter in a plurality of power plants, the output time from the tachometer at a certain time The output meter was found to be delayed in the output time of the generator output at the same time.

  If the correction value is obtained by subtracting the apparent output fluctuation that is not delayed from the output of the generator that is delayed by the delay time, an appropriate correction value cannot be obtained. Therefore, in the abnormality detection method, in the correction step, the apparent output fluctuation delayed by the delay time of the output from the output meter with respect to the output from the tachometer is subtracted from the output output from the output meter. The correct correction value is obtained.

  Further, in any of the prime mover abnormality detection methods for obtaining an apparent output fluctuation of the prime mover, in the abnormality determination step, a reference for the output corrected in the correction step and the output detected by the output meter You may perform the output fluctuation | variation calculation process which makes the difference with an output the fluctuation | variation of this output.

  Further, in any one of the prime mover abnormality detection methods for executing the output fluctuation calculation step, the output fluctuation calculation step may include an output change rate allowed when the prime mover and the generator are in normal operation. A reference output which is an output obtained by using the reference output may be used as the reference output.

A control apparatus for a prime mover as one aspect according to the invention for achieving the above object is as follows:
In the control device of the prime mover mechanically connected to the generator, the prime mover depends on whether or not the fluctuation range of the output of the generator detected by the output meter is outside the range of the allowable output fluctuation range. An abnormality determination unit that determines whether or not there is an abnormality, the allowable output fluctuation range that is a determination criterion in the abnormality determination unit, and the output that is detected by the output meter that is a determination target in the abnormality determination unit; A correction unit that corrects one of the generator and the prime mover detected by a tachometer, and the abnormality determination unit determines that the prime mover is abnormal. Then, a trip signal output unit for outputting a trip signal to the operation unit capable of tripping the prime mover and tripping the prime mover is provided.

  In the control device, similarly to the above-described abnormality detection method, it is possible to reduce erroneous detection of a prime mover abnormality when the power system fluctuates. As a result, the control device can reduce the number of erroneous trips of the prime mover.

  Further, in the motor control device, the correction unit uses a rotation speed variation calculation unit for obtaining a rotation speed fluctuation range of the rotation speed using the one rotation speed, and the rotation speed fluctuation width is increased. Accordingly, an allowable fluctuation range correction unit that corrects the allowable output fluctuation range so that the allowable output fluctuation range increases, and the abnormality determination unit includes the fluctuation range of the output detected by the output meter. It may be determined whether or not the prime mover is abnormal depending on whether or not is outside the range of the allowable output fluctuation range corrected by the correction unit.

  Further, in the motor control apparatus having the permissible fluctuation range correction unit, the rotation speed fluctuation range calculation unit is configured such that when the rotation number is lower than a rated rotation number, the prime mover and the generator are An upper reference speed calculation unit for obtaining a reference rotational speed, which is a rotational speed obtained using a rotational speed reduction rate allowed during normal operation, and increased when the rotational speed is equal to or lower than the rated rotational speed A lower reference rotational speed that is a rotational speed obtained using a rotational speed increase rate allowed when the prime mover and the generator are in normal operation, and at the same time as the upper reference rotational speed A lower reference rotational speed calculation unit that calculates a lower reference rotational speed, and a deviation calculation unit that calculates a difference between the upper reference rotational speed and the lower reference rotational speed and outputs the difference as the rotational speed fluctuation range. May be.

  Further, in any one of the prime mover control devices having the permissible fluctuation range correction unit, the abnormality determination unit may calculate a difference between the output detected by the output meter and a reference output with respect to the output. An output fluctuation calculation unit may be included.

  Further, in the control apparatus for the prime mover as the one aspect, the correction unit includes the one rotational speed, a rotational speed change rate that is a change rate per unit time of the rotational speed, the prime mover, and the generator. An apparent output fluctuation calculation unit for obtaining an apparent output fluctuation of the prime mover using the inertial moment of the rotating system, and subtracting the apparent output fluctuation from the output of the generator detected by the output meter An output calculation unit that outputs the corrected value, and the abnormality determination unit determines whether or not the fluctuation range of the output corrected by the correction unit is outside the range of the allowable output fluctuation range. In response, it may be determined whether the prime mover is abnormal.

  Further, in the motor control device having the apparent output fluctuation calculation unit, the correction unit outputs the apparent output fluctuation input to the output calculation unit from the output meter with respect to an output from the speed meter. It is preferable to have a delay time adjusting unit that delays by the output delay time.

  Further, in any one of the prime mover control devices having the permissible fluctuation range correction unit, the abnormality determination unit may calculate the output corrected by the correction unit and a reference output for the output detected by the output meter. You may have an output fluctuation | variation calculation part which makes a difference the fluctuation | variation of this output.

  Further, in any of the prime mover control devices having the output fluctuation calculation unit, the output fluctuation calculation unit uses an output change rate allowed when the prime mover and the generator are operating normally. A reference output that is a required output may be used as the reference output.

A power plant as one aspect according to the invention for achieving the above object is as follows:
One of the above control devices, the prime mover, the generator, and the operation unit are provided.

  In the present invention, even when the power system becomes unstable and the output of the generator fluctuates, it is possible to more accurately determine whether or not the prime mover is abnormal, and reduce erroneous detection of the prime mover. it can.

It is a systematic diagram of the power plant in 1st embodiment which concerns on this invention. It is explanatory drawing for demonstrating the trip of the gas turbine accompanying the fluctuation | variation of the generator output in 1st embodiment which concerns on this invention. It is explanatory drawing which shows how to obtain | require the rotation speed fluctuation range in 1st embodiment which concerns on this invention. It is a graph which shows the relationship between the rotation speed fluctuation range and correction amount in 1st embodiment which concerns on this invention. It is a flowchart which shows operation | movement of the control apparatus in 1st embodiment which concerns on this invention. It is explanatory drawing which shows the relationship between the fluctuation | variation of the rotation speed of a generator or a gas turbine, and the fluctuation | variation of a generator output. It is explanatory drawing which shows the relationship between the rotation speed fluctuation | variation range and allowable output fluctuation | variation range in a prior art. It is explanatory drawing which shows the relationship between the rotation speed fluctuation | variation range and allowable output fluctuation | variation range in 1st embodiment which concerns on this invention. It is a functional block diagram of the control apparatus in 2nd embodiment which concerns on this invention. It is explanatory drawing which shows the relationship between the rotation speed of a generator or a gas turbine, and the output of a generator and a gas turbine. It is a flowchart which shows operation | movement of the control apparatus in 2nd embodiment which concerns on this invention. It is explanatory drawing for demonstrating the trip of the gas turbine accompanying the fluctuation | variation of the gas turbine output in 2nd embodiment which concerns on this invention. It is a functional block diagram of the control apparatus in 3rd embodiment which concerns on this invention. It is explanatory drawing which shows how to obtain | require the rotation speed change rate in 3rd embodiment which concerns on this invention. It is a functional block diagram of the control apparatus in 4th embodiment which concerns on this invention.

  Hereinafter, various embodiments of a power plant according to the present invention will be described in detail with reference to the drawings.

"First embodiment"
First, the power plant as 1st embodiment is demonstrated using FIGS. 1-8.

  As shown in FIG. 1, the power plant according to the present embodiment includes a gas turbine 10 as a prime mover, a generator 20 that generates power by driving the gas turbine 10, and a control device 100.

  The gas turbine 10 includes an air compressor 11 that generates compressed air by compressing the atmosphere, a combustor 13 that generates high-temperature combustion gas by burning fuel in the compressed air, a turbine 14 that is driven by the combustion gas, It has. The rotor 15 of the turbine 14 and the rotor 21 of the generator 20 are mechanically connected. For this reason, when the rotor 15 of the turbine 14 rotates, the rotor 21 of the generator 20 also rotates. The rotor 15 of the turbine 14 or the rotor 21 of the generator 20 is provided with a rotational speed meter 25 that detects the rotational speed of one of the rotors 15 and 21. A fuel line 16 that supplies fuel to the combustor 13 is connected to the combustor 13. A fuel cutoff valve 17 is provided in the fuel line 16.

  The generator 20 and the power system 29 are electrically connected by a power line 22. The power line 22 is provided with a circuit breaker 23, a transformer 24, and an output meter 26 that detects the output of the generator 20.

  The control device 100 includes an abnormality determination unit 160 that determines whether or not the gas turbine 10 is abnormal depending on whether or not the fluctuation range of the output detected by the output meter 26 is outside the range of the allowable output fluctuation range. When the correction unit 150 that corrects the allowable output fluctuation range using the rotation speed detected by the rotation speed meter 25 and the abnormality determination unit 160 determine that there is an abnormality, the fuel cutoff valve 17 and the circuit breaker 23 that are operation units. A trip signal output unit 170 for outputting a trip signal. The fuel shut-off valve 17, which is one of the operation parts, closes when receiving this trip signal, and the fuel supply to the combustor 13 stops. Moreover, the circuit breaker 23 which is another one of the operation parts is opened when this trip signal is received, and the electrical connection between the generator 20 and the power system 29 is cut off.

  The abnormality determination unit 160 of the control device 100 includes an output fluctuation calculation unit 167 that obtains the fluctuation range ΔPg of the output from the output meter 26, and an allowable width that determines whether the output fluctuation width ΔPg is outside the range of the allowable output fluctuation width ΔPs. And a determination unit 163 and a non-allowable time determination unit 166 for determining whether or not the time during which the output fluctuation range ΔPg is outside the range of the allowable output variation range ΔPs is a predetermined time or more. .

  The output fluctuation calculation unit 167 is a reference output generator 161 that outputs the reference output Pr based on the output from the output meter 26, and the output fluctuation that is the difference between the reference output Pr and the output Pg of the generator 20 from the output meter 26. And a subtractor 162 for obtaining the width ΔPg.

  As shown in FIG. 2, the reference output Pr is an output at the current time tb that is obtained based on an output change rate that is allowed when the gas turbine 10 and the generator 20 are operating normally. The reference output generator 161 outputs an increase reference output Pri (Pr) when the output increases and a decrease reference output Prd (Pr) when the output decreases. The subtracter 162 is an increase output fluctuation width ΔPi (ΔPg) that is a difference between the output Pg of the generator 20 and the reference output Pri at the time of increase, and a difference between the output Pg of the generator 20 and the reference output Prd at the time of decrease. A decrease output fluctuation width ΔPd (ΔPg) is obtained.

  Here, the difference between the reference output Pr and the output Pg of the generator 20 from the output meter 26 is defined as the output fluctuation range ΔPg with the reference output Pr as a reference, but the output of the generator 20 before a predetermined time is used. As a reference, the difference between the output of the generator 20 serving as the reference and the output of the current generator 20 may be set as the output fluctuation range ΔPg.

  The allowable range determiner 163 includes an upper limit determiner 164 that determines whether the output variation range ΔPg from the subtractor 162 exceeds the upper limit allowable variation range ΔPsi when the output increases, and a lower limit when the output decreases. A lower limit determination unit 165 that determines whether or not the output variation range ΔPg from the subtractor 162 exceeds the allowable variation range ΔPsd. When the output fluctuation width ΔPg from the subtractor 162 is outside the range of the allowable output fluctuation width ΔPs, the allowable width determiner 164 outputs an abnormal signal indicating that an abnormal state is present. Specifically, when the output fluctuation width ΔPg from the subtractor 162 exceeds the upper limit allowable fluctuation width ΔPsi, the upper limit determiner 164 outputs an abnormal signal, and the output fluctuation width ΔPg from the subtracter 162 is lower limit allowable. If the fluctuation range ΔPsd exceeds the negative side, the lower limit determination unit 165 outputs an abnormal signal.

  The non-allowable time determination unit 166 includes a timer, and starts counting down by the timer when an abnormal signal is input from the allowable width determination unit 163. When the input of the abnormal signal continues for a predetermined time Tp (see FIG. 2), That is, when the timer reaches 0, an abnormal signal is output to the trip signal output unit 170.

  The trip signal output unit 170 outputs a trip signal to the fuel shut-off valve 17 and the circuit breaker 23, which are operation units, when an abnormal signal is input from the non-allowable time determination unit 166.

  As shown in FIG. 1, the correction unit 150 of the control device 100 includes a rotation speed fluctuation calculation unit 151 that calculates a fluctuation range of the rotation speed detected by the rotation speed meter 25, and an allowable output fluctuation according to the rotation speed fluctuation width. A correction amount calculation unit 155 that calculates a correction amount of the width, and an allowable fluctuation range correction unit 156 that corrects the allowable output fluctuation range according to the correction amount.

  The rotational speed fluctuation range calculation unit 151 includes an upper reference rotational speed calculator 152 for determining the current upper reference rotational speed, a lower reference rotational speed calculator 153 for determining the current lower reference rotational speed, and the upper reference rotational speed and the lower reference. A subtractor (deviation calculator) 154 that outputs a difference from the rotational speed as a rotational speed fluctuation range.

  As shown in FIG. 3, when the upper reference rotational speed Nru decreases when the rotational speed is higher than the rated rotational speed, the rotational speed allowed when the gas turbine 10 and the generator 20 are operating normally. This is the number of rotations obtained using the decrease rate. Further, the lower reference rotational speed Nrd is obtained using the rotational speed increase rate that is allowed when the gas turbine 10 and the generator 20 are operating normally when the rotational speed increases when the rotational speed is equal to or lower than the rated rotational speed. The number of rotations The subtractor 154 obtains the difference between the current upper reference rotational speed Nru and the current lower reference rotational speed Nrd, and outputs this difference as the current rotational speed fluctuation range ΔNp.

  Here, the rated rotational speed is a rotational speed determined by the frequency of the power system 29. Further, as the current rotational speed fluctuation range ΔNp, for example, a difference between the maximum rotational speed and the minimum rotational speed in a time period from a current time to a predetermined time in advance may be adopted.

  The correction amount calculation unit 155 has a function F that converts the rotation speed fluctuation range into a correction amount. This function F is a function that outputs a correction amount proportional to the magnitude of the rotational speed fluctuation range, for example, as shown in FIG. Accordingly, the correction amount calculation unit 155 outputs a larger correction amount in proportion to the input rotational speed fluctuation range when the magnitude of the rotation speed fluctuation range increases.

  As shown in FIG. 1, the allowable fluctuation range correction unit 156 includes an upper limit corrector 157 that adds a correction amount to the upper limit allowable fluctuation range ΔPsi held by the upper limit determination unit 164 of the abnormality determination unit 160, and a lower limit determination unit 165. And a lower limit corrector 158 that subtracts the correction amount from the lower limit allowable fluctuation range ΔPsd that is held. Therefore, as the magnitude of the rotational speed fluctuation range increases, the upper limit allowable fluctuation range ΔPsi held by the upper limit determination unit 164 becomes larger, and the lower limit allowable fluctuation range ΔPsd held by the lower limit determination unit 165 becomes negative. Becomes larger.

  Next, the processing flow of the control device 100 will be described according to the flowchart shown in FIG.

  The allowable fluctuation range correction unit 156 of the control device 100 receives the rotational speed from the rotational speed meter 25 and, based on this rotational speed, the allowable output fluctuation range possessed by the allowable width determination unit 163 of the abnormality determination unit 160. Correction is performed (correction step (S1)). In this correction step (S1), first, the rotational speed fluctuation range calculation unit 151 obtains the rotational speed fluctuation range from the rotational speed meter 25 (rotational speed fluctuation range calculation step (S2)). Next, the correction amount calculation unit 155 obtains a correction amount proportional to the magnitude of the rotational speed fluctuation range, and the allowable fluctuation range correction unit 156 has the allowable fluctuation range ΔPs held by the allowable range determination unit 163 of the abnormality determination unit 160. Is corrected (allowable fluctuation range correction step (S3)). Specifically, as described above, the allowable fluctuation range correction unit 156 calculates the upper limit allowable fluctuation range ΔPsi held by the upper limit determination unit 164 of the allowable range determination unit 163 in proportion to the magnitude of the rotational speed fluctuation range. The lower limit allowable fluctuation range ΔPsd held by the lower limit determination unit 165 of the allowable range determination unit 163 is increased to the negative side.

  Thus, the correction process (S1) is completed.

  In parallel with the correction process (S1), the abnormality determination unit 160 determines whether or not the gas turbine 10 is abnormal (abnormality determination process (S4)). In this abnormality determination step (S4), first, the reference output generator 161 receives the output from the output meter 26, and outputs the reference output Pr based on this output. The subtractor 162 obtains an output fluctuation range ΔPg that is the difference between the reference output Pr and the output Pg of the generator 20 from the output meter 26 (output fluctuation range calculation step (S5)). Based on this output fluctuation range ΔPg, it is determined whether or not each of the determiners 163 and 166 is abnormal (determination step (S6)).

  In this determination step (S 6), the allowable width determining unit 163 receives the output fluctuation range ΔPg from the subtractor 162, and determines whether or not the output fluctuation range ΔP is outside the allowable output fluctuation range ΔPs corrected by the correction unit 150. to decide. Then, when the output fluctuation range ΔPg is outside the range of the allowable output fluctuation range ΔPs, the allowable range determination unit 163 outputs an abnormal signal indicating an abnormal state. When this abnormal signal is output, the non-allowable time determination unit 166 determines whether or not the time during which the output fluctuation width ΔPg is outside the range of the allowable output fluctuation width ΔPs is equal to or longer than the predetermined time Tp. If it is equal to or longer than time Tp, an abnormal signal is output to trip signal output section 170. That is, in this determination step (S6), if the output fluctuation width ΔPg is outside the range of the allowable output fluctuation width ΔPs and this state continues for a predetermined time Tp, an abnormal signal is output to the trip signal output unit 170. On the other hand, if the output fluctuation range ΔPg is not outside the allowable output fluctuation range ΔPs, or if the output fluctuation range ΔPg is outside the allowable output fluctuation range ΔPs does not continue for the predetermined time Tp, the process returns to step 1. .

  When the abnormality determination unit 160 outputs an abnormality signal (Yes in S6), the trip signal output unit 170 outputs a trip signal to the operation unit as described above (S7). As a result, the gas turbine 10 trips.

  As shown in FIG. 6, even if the output of the gas turbine 10 is constant, when the power system 29 changes, the rotational speed of the generator 20 and the output of the generator 20 change. The rotational speed and the output have a very high correlation. When the rotational speed varies greatly, the output also varies greatly. However, there is a slight phase shift between the rotational speed and the output.

  In the technique described in Patent Document 1 described in the “Background Art” section, in Patent Document 1, the difference between the current output of the generator 20 and the output of the generator 20 a predetermined time ago is a fixed value. The value is compared to determine the state of the gas turbine 10. That is, as shown in FIG. 7, the allowable output fluctuation range ΔPs of the output of the generator 20 that is the reference value is constant regardless of the change in the rotation speed fluctuation range ΔNp. Therefore, even if the output of the gas turbine 10 is constant, if the power system 29 fluctuates and the output of the generator 20 fluctuates greatly, for example, the gas turbine 10 may be tripped at time tx in FIG.

  On the other hand, in the present embodiment, as shown in FIG. 8, the allowable output fluctuation range ΔPs is increased in proportion to the rotational speed fluctuation range ΔNp, and more specifically, the rotational speed fluctuation range ΔNp. The upper limit allowable fluctuation range ΔPsi is increased and the lower limit allowable fluctuation range ΔPsd is increased to the negative side. Therefore, as shown in FIG. 6, even if the rotation speed of the generator 20 greatly fluctuates due to a large fluctuation of the power system 29 and the output of the generator 20 fluctuates greatly, the output fluctuation width ΔPg at this time is allowable. It falls within the range of the output fluctuation range ΔPs, and the gas turbine 10 is not tripped. In other words, in the present embodiment, for example, when the output of the gas turbine 10 is constant, even if the power system 29 fluctuates greatly and the output of the generator 20 fluctuates greatly, the gas turbine 10 is abnormal. Is not determined, and the operation of the gas turbine 10 is continued.

  As described above, in the present embodiment, it is possible to reduce erroneous detection of gas turbine abnormality and erroneous trip of the gas turbine 10 when the power system 29 fluctuates.

"Second embodiment"
Next, the power plant as 2nd embodiment is demonstrated using FIGS. 9-12.

  The power plant of this embodiment and the following embodiments is a modification of the control device 100 of the first embodiment, and the other configurations are the same as those of the power plant of the first embodiment. Accordingly, in the present embodiment and the following embodiments, the contents of change of the control device 100 of the first embodiment will be mainly described.

  As shown in FIG. 9, the control device 100a according to the present embodiment determines whether or not the gas turbine 10 is abnormal depending on whether or not the output fluctuation range is out of the allowable output fluctuation range. The determination part 160a, the correction | amendment part 110 which correct | amends the output detected by the output meter 26, and the trip signal output part 170 similar to 1st embodiment are provided.

  The abnormality determination unit 160a includes an output variation calculation unit 167a that calculates a variation range ΔP of the output Pt from the correction unit 110, and an allowable range determination unit 163 and an allowable outside time determination unit 166 similar to those in the first embodiment. ing.

  The output fluctuation calculation unit 167a obtains a reference output generator 161 that outputs the reference output Pr based on the output from the output meter 26, and an output fluctuation width ΔP that is a difference between the reference output Pr and the output Pt from the correction unit 110. A subtractor 162a.

  As in the first embodiment, the reference output generator 161 outputs an increase reference output Pri (Pr) when the output increases and a decrease reference output Prd (Pr) when the output decreases. The subtractor 162a is an increase output fluctuation width ΔPi that is a difference between the output Pt from the correction unit 110 and the increase reference output Pri, and a decrease that is a difference between the output Pt from the correction unit 110 and the decrease reference output Prd. The output fluctuation range ΔPd is obtained.

  Here, the difference between the reference output Pr and the output Pt from the correction unit 110 is defined as the output fluctuation range ΔP with the reference output Pr as a reference, but the output Pt from the correction unit 110 a predetermined time before is used as a reference. Thus, the difference between the output from the correction unit 110 serving as the reference and the output from the current correction unit 110 may be used as the output fluctuation range ΔPg.

  The allowable width determiner 163 and the non-allowable time determiner 166 are the same as those in the first embodiment as described above.

  The correction unit 110 of the control device 100a is obtained by the apparent output fluctuation calculation unit 111 that obtains the apparent output fluctuation of the gas turbine 10 and the apparent output fluctuation calculation unit 111 by using the rotation speed detected by the rotation speed meter 25. And an output calculation unit 118 that obtains the output Pt of the gas turbine 10 using the apparent output fluctuation of the gas turbine 10 and the output Pg of the generator 20 detected by the output meter 26. That is, the correction unit 110 corrects the output Pg of the generator 20 detected by the output meter 26, and outputs the output Pt of the gas turbine 10 as the corrected output.

The output Pt of the gas turbine 10 is obtained from the output Pg of the generator 20 detected by the output meter 26 as shown in the following formula (1), and the gas turbine due to the inertia force of the rotating system in the gas turbine 10 and the generator 20. This is a value obtained by subtracting 10 apparent output fluctuations Δp.
Pt = Pg−Δp (1)

  Therefore, the output calculator 118 calculates a deviation between the output Pg of the generator 20 detected by the output meter 26 and the apparent output fluctuation Δp of the gas turbine 10 obtained by the apparent output fluctuation calculator 111. It is.

  The apparent output fluctuation Δp of the gas turbine 10 due to the inertial force of the rotating system in the gas turbine 10 and the generator 20 can be expressed by the following equation (2).

Δp = Tr × ω
= −I × dω / dt × ω
= −I × (2π / 60) ² × dN / dt × N (2)
Tr: Acceleration torque (= −I × dω / dt) [N · m]
ω: angular velocity (= 2πN / 60) [rad / s]
I: Moment of inertia [kg · m ² ]
t: Time [s]
N: Number of revolutions [rpm]

  In addition, the inertia moment I in Formula (2) is an inertia moment of the rotating system in the gas turbine 10 and the generator 20. For this reason, this moment of inertia I is the moment of inertia of the rotor 12 of the air compressor 11, the rotor 15 of the turbine 14, and the rotor 21 of the generator 20 in the gas turbine 10. Further, in Equation (2), the only variation parameter with time change is the rotation speed N, and the other parameters are fixed values. For this reason, the apparent output fluctuation Δp of the gas turbine 10 represented by the equation (2) can be obtained by detecting the rotational speed N.

  As shown in FIG. 10, even if the output Pt of the gas turbine 10 is constant, when the power system 29 changes, the rotational speed of the generator 20 and the output Pg of the generator 20 change. The output fluctuation of the generator 20 due to the fluctuation of the electric power system 29 is as follows: the apparent output fluctuation Δp of the gas turbine 10 shown in the above equation (2) with respect to the net output Pt of the gas turbine 10. Become. Therefore, even when the power system 29 fluctuates, as shown in the equation (1), the apparent output fluctuation Δp of the gas turbine 10 is subtracted from the output Pg of the generator 20 detected by the output meter 26. The net output Pt of the gas turbine 10 can be obtained. When the gas turbine 10, the generator 20, and the power system 29 are stable, the apparent output fluctuation Δp of the gas turbine 10 is substantially “0”. Therefore, in this case, as can be understood from the equation (1), the output Pt of the gas turbine 10 and the output Pg of the generator 20 are substantially equal.

  By the way, when the rotational speed N of the gas turbine 10 and the generator 20 fluctuates at a constant period T, the phase of the output of the generator 20 is theoretically shifted by T / 4 with respect to the phase of the rotational speed. . However, in a plurality of power plants, when the phase of the rotational speed detected by the tachometer is compared with the phase of the actual output detected by the power meter, the phase of the output detected by the power meter is It was found that the phase of the rotational speed detected at 1 was delayed from T / 4. That is, it has been found that the actual output phase detected by the output meter is delayed by a delay time Td from the theoretical output phase. In other words, it has been found that the output time of the output of the generator at the same certain time is delayed by the delay time Td with respect to the output time from the speed meter at a certain time.

  Although the cause of the delay time Td is not clearly known, it is considered that the output meter hardware is caused by the delay time. The output meter basically includes an ammeter, a voltmeter, and a calculator that multiplies the current value detected by the ammeter and the voltage value detected by the voltmeter. Thus, since the output meter has obtained an output through a plurality of stages, the phase of the output detected by the output meter is considered to be delayed with respect to the theoretical output phase.

  When the output Pt of the gas turbine 10 is obtained using the equation (1), the apparent output fluctuation Δp of the gas turbine 10 in the equation (1) is the rotational speed as described above using the equation (2). Required if detected. For this reason, the phase of the apparent output fluctuation Δp obtained from the rotational speed substantially matches the phase of the theoretical output fluctuation, and is not substantially delayed from the theoretical output fluctuation. On the other hand, since the output Pg of the generator 20 in the equation (1) is detected by the output meter 26, the phase of the output Pg of the generator 20 is a delay time Td minutes from the theoretical output phase. Running late.

  It is assumed that the output Pt of the gas turbine 10 is obtained by subtracting the apparent output fluctuation Δp whose phase is not delayed from the output Pg of the generator 20 whose phase is delayed by the delay time Td. In this case, if the delay time Td is a relatively short time, there is not much problem, but if the delay time Td is a relatively long time, a large error is included in the required output Pt of the gas turbine 10. . In particular, when the delay time Td is ½ of the fluctuation cycle T of the rotational speed, the positive peak value of the output fluctuation must be subtracted from the positive peak value of the output. The negative peak value of the output fluctuation is subtracted from the peak value, and the fluctuation of the output of the gas turbine 10 becomes extremely larger than the apparent fluctuation.

  Therefore, the apparent output fluctuation calculation unit 111 of the present embodiment calculates the apparent output fluctuation Δp of the gas turbine 10 in which the delay time Td is adjusted from the rotational speed N detected by the rotational speed meter 25 based on the above knowledge. Ask. Specifically, as shown in FIG. 9, the apparent output fluctuation calculation unit 111 according to the present embodiment uses the rotational speed N detected by the rotational speed meter 25 and does not consider the delay time Td. An output fluctuation calculating unit 120 for obtaining the above output fluctuation and a delay time adjusting unit 112 for delaying the apparent output fluctuation by a predetermined delay time Td are provided.

The output fluctuation calculation unit 120 includes a rotation speed change rate calculation unit 130 that obtains a rotation speed change rate (dN / dt) using two rotation speeds sampled at different sampling times, and the gas turbine 10 and the generator 20 An inertia moment generator 121 that outputs the inertia moment I of the rotating system, a constant generator 122 that outputs [− (2π / 60) ² ] that is a constant in the equation (2), and a plurality of multipliers 123 and 124. , 125. The multipliers 123, 124, and 125 include a first multiplier 123 that multiplies the moment of inertia I and a constant [− (2π / 60) ² ], and an output [−I × (2π / 60] from the first multiplier 123. ) ² ] multiplied by the rotation rate change rate (dN / dt), and the output [−I × (2π / 60) ² × dN / dt] from the second multiplier 124 is set to the rotation number N. A third multiplier 125 for multiplying. That is, the output fluctuation calculation unit 120 executes the calculation of Expression (2).

  The rotational speed change rate calculation unit 130 outputs a rotational speed from the rotational speed meter 25 by delaying the rotational speed by a predetermined time Ts, and a difference between the rotational speed from the rotational speed meter 25 and the rotational speed from the delay device 133. A subtracter 134 to be obtained, a time generator 132 that outputs a predetermined time Ts, and a divider 139 that divides the output from the subtractor 134 by the predetermined time Ts from the time generator 132. That is, the rotation speed change rate calculation unit 130 sets the average rotation speed change rate between the current rotation speed and the rotation speed past the predetermined time Ts from the current time as the current rotation speed change rate.

  Next, the processing flow of the control device 100a will be described according to the flowchart shown in FIG.

  The correction unit 110 of the control device 100a receives the rotational speed N from the rotational speed meter 25 and the output Pg of the generator 20 from the output meter 26, corrects the output Pg, and outputs the output Pt of the gas turbine 10. (Correction process (S10)).

  In this correction step (S10), first, the output fluctuation calculation unit 120 of the correction unit 110 obtains an apparent output fluctuation Δp of the gas turbine 10 (apparent output fluctuation calculation step (S12)). At this time, the rotation speed change rate calculation unit 130 of the output fluctuation calculation unit 120 obtains the rotation speed change rate by the method described above. The output fluctuation calculation unit 120 obtains an apparent output fluctuation Δp of the gas turbine 10 using the rotation speed change rate, the rotation speed, the inertia moment of the rotation system, and the like according to the equation (2).

  In the correction step (S10), subsequently, the delay time adjusting unit 112 adjusts the apparent output fluctuation Δp of the gas turbine 10 obtained by the output fluctuation calculating unit 120 to the apparent output fluctuation Δp before the delay time Td. (Delay time adjustment step (S13)). Specifically, the delay time adjustment unit 112 is a delay unit, and the delay time adjustment unit 112 delays the apparent output fluctuation Δp of the gas turbine 10 obtained by the output fluctuation calculation unit 120 by the delay time Td before output. To do.

  As a result, the apparent output fluctuation Δp output from the delay time adjustment unit 112 becomes an apparent output fluctuation considering the delay time Td of the output meter 26. The apparent output fluctuation calculating step (S11) is a step in which the apparent output fluctuation calculating step (S12) and the delay time adjusting step (S13) are combined to obtain an apparent output fluctuation considering the delay time Td of the output meter 26. Is made.

  In the correction step (S10), the output calculation unit 118 further determines the apparent output of the gas turbine 10 obtained by the apparent output fluctuation calculation unit 111 from the output Pg of the generator 20 from the output meter 26 according to the equation (1). Is subtracted to obtain the output Pt of the gas turbine 10 (output calculation step (S14)). The output Pg of the generator 20 from the output meter 26 is an output substantially delayed from the current time by the delay time Td, but the apparent output fluctuation Δp of the gas turbine 10 from the apparent power fluctuation calculation unit 111 is also from the current time. This is an apparent output fluctuation substantially delayed by the delay time Td. For this reason, there is no phase shift based on the delay time Td between the output Pg of the generator 20 handled by the output calculation unit 118 and the apparent output fluctuation Δp of the gas turbine 10. Therefore, the output calculation unit 118 can obtain an accurate output of the gas turbine 10.

  The correction process (S10) is thus completed.

  The abnormality determination unit 160a determines whether or not the gas turbine 10 is abnormal (abnormality determination step (S4a)). In this abnormality determination step (S4a), first, the reference output generator 161 receives the output from the output meter 26, and outputs the reference output Pr based on this output. The subtractor 162a obtains an output fluctuation range ΔP that is a difference between the reference output Pr and the output Pt of the gas turbine 10 from the correction unit 110 (output fluctuation range calculation step (S5a)). Based on this output fluctuation range ΔP, it is determined whether or not each of the determiners 163 and 166 is abnormal (determination step (S6a)).

  In this determination step (S6a), the allowable width determiner 163 receives the output fluctuation width ΔPg from the subtractor 162a, and determines whether or not the output fluctuation width ΔP is outside the predetermined allowable output fluctuation width ΔPs. . Then, when the output fluctuation range ΔPg is outside the range of the allowable output fluctuation range ΔPs, the allowable range determination unit 163 outputs an abnormal signal indicating an abnormal state. When this abnormal signal is output, the non-allowable time determination unit 166 determines whether or not the time during which the output fluctuation width ΔPg is outside the range of the allowable output fluctuation width ΔPs is equal to or longer than the predetermined time Tp. If it is equal to or longer than time Tp, an abnormal signal is output to trip signal output section 170.

  Similar to the first embodiment, the trip signal output unit 170 outputs a trip signal to the operation unit as described above when the abnormality determination unit 160a outputs an abnormality signal (Yes in S6a) (S7). . As a result, the gas turbine 10 trips.

  For example, as shown in FIG. 12, it is assumed that the output Pt of the gas turbine 10 starts to decrease relatively rapidly from time ta. The output Pt of the gas turbine 10 shown in FIG. 12 is a net output that does not include the apparent output fluctuation Δp of the gas turbine 10. As a result, a decrease output fluctuation width ΔPd (ΔP) that is a difference between the decrease reference output Prd (Pr) and the output Pt of the gas turbine 10 occurs. When the output Pt of the gas turbine 10 decreases relatively rapidly thereafter, the output fluctuation width ΔPd at the time of decrease gradually increases toward the negative side. When the output fluctuation width ΔPd at the time of decrease exceeds the lower limit allowable fluctuation width ΔPsd (ΔPs) determined in advance at time tb, the lower limit determiner 165 outputs an abnormal signal to the non-allowable time determiner 166. To do. When the input of the abnormal signal continues for the predetermined time Tp, the non-allowable time determination unit 166 outputs an abnormal signal to the trip signal output unit 170 at time tc after the predetermined time Tp from time tb. As a result, the trip signal output unit 170 outputs a trip signal to the operation unit as described above, and the gas turbine 10 trips.

  As described above, in the present embodiment, for example, even when the power system 29 becomes unstable and the output balance between the gas turbine 10 and the generator 20 is lost, the accurate gas turbine 10 is output from the output of the generator 20. Can be obtained.

  In the present embodiment, when the output Pt of the gas turbine 10 is constant, even if the output Pg of the generator 20 fluctuates due to the instability of the power system 29, it is accurately obtained as described above. Since it is determined whether or not the gas turbine 10 is abnormal according to the output Pt of the gas turbine 10, it is possible to reduce erroneous detection of the gas turbine abnormality and erroneous trip of the gas turbine 10.

"Third embodiment"
Next, a power plant as a third embodiment will be described with reference to FIGS. 13 and 14.

  The control device 100b of this embodiment is obtained by changing the rotation speed change rate calculation unit 130 in the control device 100a of the second embodiment, and other configurations are basically the same as those of the control device 100a of the second embodiment. . Therefore, in the following, this change will be mainly described.

  First, how to determine the rotation speed change rate in the rotation speed change rate calculation unit 130b of the present embodiment will be described with reference to FIG.

  When calculating the rotation speed change rate at the first time t1, first, the first rotation speed N1 output from the rotation speed meter 25 at the first time t1 and the second time before the predetermined time Ts from the first time t1. Using the second rotation speed N2 output from the rotation speed meter 25 at t2, a first rotation speed change amount ΔN1 that is the difference between the both rotation speeds N1 and N2 is obtained. Next, the difference between the rotational speeds N3 and N1 is calculated using the third rotational speed N3 and the first rotational speed N1 output from the rotational speed meter 25 at the third time t3 after a predetermined time Ts from the first time t1. The second rotation speed change amount ΔN2 is obtained.

  Next, an average change amount ΔNa that is an average value of the first rotation speed change amount ΔN1 and the second rotation speed change amount ΔN2 is obtained. Next, the average change amount ΔNa is divided by the predetermined time Ts, and this value is set as the rotation speed change rate at the first time t1.

  That is, here, the first average rotational speed change rate between the first time t1 and the second time t2, and the second average rotational speed change rate between the first time t1 and the third time t3, Is the rotation speed change rate at the first time t1.

  The predetermined time Ts between the first time t1 and the second time t2, and the predetermined time Ts between the first time t1 and the third time t3 are times less than the expected delay time Td.

  By the way, when the rotation rate change rate at the first time t1 is obtained as described above, the third rotation number N3 at the third time t3 that is a future time with respect to the first time t1 is necessary.

  Further, in the output calculation unit 118, an object to be subtracted from the apparent output fluctuation obtained using the rotation speed change rate at the first time t1 is the output of the generator 20 at the first time t1. The output of the generator 20 at the first time t1 is a time that is a future time by the predetermined time Ts with respect to the first time t1 because the predetermined time Ts is equal to or less than the expected delay time Td. It is an output that is output from the output meter 26 at a future time further than the time t3, that is, at a future fourth time t4 by a delay time Td from the first time t1. Therefore, when viewed from the fourth time t4 when the output of the generator 20 at the first time t1 is obtained, the third time t3 is a past time. For this reason, when the output calculation unit 118 obtains the output of the gas turbine 10 at the first time t1, the third time t3 is a past time with respect to the fourth time t4. On the other hand, the third rotation speed N3 at the third time t3, which is a future time, can be obtained.

  The rotational speed change rate calculation unit 130b of the present embodiment obtains the rotational speed change rate by the above method. Therefore, as shown in FIG. 13, the rotational speed change rate calculation unit 130 b includes a constant generator 131 that outputs a constant “2”, a time generator 132 that outputs a predetermined time Ts, and a rotational speed meter 25. A first delay unit 133 that outputs the rotation number from the first delay unit 133 after being delayed by a predetermined time Ts, a first subtractor 134 that obtains a difference between the rotation number from the rotation meter 25 and the rotation number from the first delay unit 133, A second delay unit 135 that outputs the number of rotations from the first delay unit 133 with a delay of a predetermined time Ts, and a second to obtain a difference between the number of rotations from the first delay unit 133 and the number of rotations from the second delay unit 135. A subtractor 136; an adder 137 that adds the output from the second subtractor 136 to the output from the first subtractor 134; and a first division that divides the output from the adder 137 by “2” from the constant generator 131. From the first divider 138 Having a second divider 139 dividing the force at a predetermined time Ts from the time generator 132, a.

  Here, it is assumed that the third rotation speed N3 at the third time t3 is output from the rotation speed meter 25 in the rotation speed change rate calculation unit 130b. At this time, the first delay unit 133 outputs the first rotational speed N1 at the first time t1 before the predetermined time Ts from the third time t3. The first subtracter 134 outputs a second rotational speed change amount ΔN2 that is a difference between the first rotational speed N1 and the third rotational speed N3. At this time, the second delay unit 135 outputs the second rotational speed N2 at the second time t2 that is a predetermined time Ts before the first time t1. The second subtracter 136 is a first rotational speed change amount ΔN1 that is a difference between the first rotational speed N1 that is the output from the first delayer 133 and the second rotational speed N2 that is the output from the second delayer 135. Is output. The adder 137 and the first divider 138 obtain an average change amount ΔNa that is an average value of the first rotation speed change amount ΔN1 and the second rotation speed change amount ΔN2. The second divider 139 divides the average change amount ΔNa by the predetermined time Ts and outputs the rotation speed change rate at the first time t1.

  In the above, after obtaining the average change amount ΔNa, the average change amount ΔNa is divided by the predetermined time Ts to obtain the rotation speed change rate. However, the first rotation speed change amount ΔN1 and the second rotation speed change amount are obtained. After obtaining ΔN2, the rate of change of these amounts of change may be obtained, and the average value of each rate of change may be used as the rate of change in the rotational speed at the first time t1.

  By the way, as described above with reference to FIG. 14, the output operation unit 118 subtracts the apparent output fluctuation obtained by using the rotational speed change rate at the first time t1 at the first time t1. The output of the generator 20 at. The output of the generator 20 at the first time t1 is output from the output meter 26 at the future fourth time t4 by the delay time Td from the first time t1.

  On the other hand, the rotational speed change rate at the first time t1 is obtained using the rotational speed output from the rotational speed meter 25 at the future third time t3 by a predetermined time Ts from the first time t1. Therefore, the time at which the rotation speed change rate at the first time t1 is obtained is after the third time t3 in the future by the predetermined time Ts from the first time t1.

  For this reason, the time at which the output fluctuation calculating unit 120b outputs the apparent output fluctuation Δp of the gas turbine 10 at the first time t1 is also after the third time t3 in the future by the predetermined time Ts from the first time t1. . Therefore, the apparent output fluctuation Δp, which is the output from the output fluctuation calculation unit 120b, is already delayed by the predetermined time Ts, so this apparent output fluctuation Δp can be obtained by simply delaying (Td−Ts). The difference in the delay time Td between the output fluctuation Δp and the output of the generator 20 from the output meter 26 is eliminated.

  Therefore, unlike the second embodiment, the delay time adjusting unit 112b of the present embodiment delays the apparent output fluctuation Δp, which is an output from the output fluctuation calculating unit 120b, by (Td−Ts).

  The apparent output fluctuation Δp delayed by (Td−Ts) by the delay time adjustment unit 112b is sent to the output calculation unit 118 of the correction unit 110b as the output of the apparent output fluctuation calculation unit 111b. In the output calculation unit 118, as in the second embodiment, the apparent output fluctuation Δp from the apparent output fluctuation calculation unit 111b is subtracted from the output Pg from the output meter 26, and the subtraction result of the gas turbine 10 is obtained. The net output is output to the abnormality determination unit 160a.

  As described above, in the present embodiment, since the rotational speed change rate is obtained from three times, a more accurate rotational speed change rate can be obtained. In the present embodiment, as shown in FIG. 14, not only the average rotational speed change rate between this time t1 and the past time t2 but also the time t1 and the future time t3 with reference to the time t1. The average value of the average rotational speed change rate is used as the average rotational speed change rate at time t1. For this reason, in the present embodiment, when the rotational speed at the time t1 at which the rotational speed change rate is obtained takes a maximum value or a minimum value, a more accurate rotational speed change rate can be obtained than in the second embodiment.

"Fourth embodiment"
Next, a power plant as a fourth embodiment will be described with reference to FIG.

  The control device 100c of the present embodiment is obtained by changing the position of the delay time adjusting unit 112 in the control device 100a of the second embodiment, and the other configurations are basically the same as those of the control device 100a of the second embodiment. . Therefore, in the following, this change will be mainly described.

  The delay time adjustment unit 112 of the second embodiment is disposed between the apparent output fluctuation calculation unit 120 and the output calculation unit 118. On the other hand, the delay time adjustment unit 112 c of the present embodiment is disposed between the rotation speed meter 25 and the apparent output fluctuation calculation unit 120.

  In the present embodiment, the rotational speed detected by the rotational speed meter 25 is delayed by the apparent time Td by the delay time adjusting unit 112 c and then input to the apparent output fluctuation calculating unit 120. As a result, the apparent output fluctuation Δp of the gas turbine 10 obtained by the apparent output fluctuation calculating unit 120 is already delayed by the apparent time Td. Therefore, in this embodiment, as in the second embodiment, the apparent output fluctuation Δp from the apparent output fluctuation calculator 120 is input to the output calculator 118 without adjusting the delay time.

  As described above, the delay time adjustment of the output fluctuation with respect to the delay of the output from the output meter 26 is adjusted to the apparent output fluctuation of the gas turbine 10 which is the output of the apparent output fluctuation calculating unit 120 as in the first embodiment. Even if it is performed, it may be performed with respect to the rotational speed that is an input value of the apparent output fluctuation calculation unit 120 as in this embodiment. Therefore, also in the third embodiment, similarly to the present embodiment, the delay time adjusting unit may be arranged between the rotational speed meter 25 and the apparent output fluctuation calculating unit 120b. In the third embodiment, the delay time adjustment is also performed by setting the predetermined time Ts for delaying the rotation speed by the first delay unit 133 and the second delay unit 135 in the apparent output fluctuation calculation unit 120b as the delay time Td. be able to.

  In all of the above embodiments, the gas turbine is a power plant with a prime mover. However, the prime mover is not limited to a gas turbine, and may be, for example, a steam turbine or a windmill.

  DESCRIPTION OF SYMBOLS 10 ... Gas turbine, 11: Air compressor, 13: Combustor, 14: Turbine, 17: Fuel cutoff valve, 20: Generator, 23: Circuit breaker, 25: Speedometer, 26: Output meter, 100, 100a , 100b, 100c: control device, 110, 110b: correction unit, 111, 111b: apparent output fluctuation calculation unit, 112, 112a, 112b, 112c: delay time adjustment unit, 120, 120b: output fluctuation calculation unit, 130, 130b : Rotational speed change rate calculation unit, 160 and 160a: abnormality determination unit, 170: trip signal output unit

Claims (17)

In the abnormality detection method for the prime mover mechanically connected to the generator,
An abnormality determination step of determining whether or not the prime mover is abnormal depending on whether or not the fluctuation range of the output of the generator detected by an output meter is outside the range of the allowable output fluctuation range;
One of the allowable output fluctuation range that is a determination criterion in the abnormality determination step and the output detected by the output meter that is a determination target in the abnormality determination step is detected by a tachometer. A correction step of correcting using one of the number of revolutions of the generator and the prime mover;
A method for detecting an abnormality of a prime mover, characterized by: In the motor | power_engine abnormality detection method of Claim 1,
In the correction step, a rotation speed fluctuation calculation step for obtaining a rotation speed fluctuation width of the rotation speed using the one rotation speed, and the allowable output fluctuation width is increased as the rotation speed fluctuation width increases. An allowable fluctuation range correction step of correcting the allowable output fluctuation range so as to increase,
In the abnormality determination step, whether or not the prime mover is abnormal depending on whether or not the fluctuation range of the output detected by the output meter is outside the range of the allowable output fluctuation range corrected in the correction step. An abnormality detection method for a prime mover, characterized by determining whether or not. In the motor abnormality detection method according to claim 2,
In the rotation speed variation calculation step,
Upper reference rotation which is a rotation speed obtained using a rotation speed reduction rate allowed when the prime mover and the generator are operating normally when the rotation speed is lower than the rated rotation speed An upper reference rotation number calculation step for obtaining a number;
The lower reference rotational speed, which is the rotational speed obtained using the rotational speed increase rate allowed when the prime mover and the generator are operating normally when the rotational speed increases when the rotational speed is equal to or lower than the rated rotational speed. A lower reference rotational speed calculation step for obtaining a lower reference rotational speed at the same time as the upper reference rotational speed;
Obtaining a difference between the upper reference rotation speed and the lower reference rotation speed, and outputting the difference as the rotation speed fluctuation range;
A method for detecting an abnormality of a prime mover, characterized by: In the motor abnormality detection method according to claim 2 or 3,
In the abnormality determination step, an output fluctuation calculation step in which a difference between the output detected by the output meter and a reference output with respect to the output is a fluctuation of the output,
An abnormality detection method for a prime mover, characterized by being executed. In the motor | power_engine abnormality detection method of Claim 1,
In the correction step, using the one rotational speed, the rotational speed change rate that is a change rate per unit time of the rotational speed, and the inertia moment of the rotating system in the prime mover and the generator, The apparent output fluctuation is obtained, and a value obtained by subtracting the apparent output fluctuation from the output of the generator detected by the output meter is set as a corrected output,
In the abnormality determination step, it is determined whether or not the prime mover is abnormal depending on whether or not the fluctuation range of the output corrected in the correction step is outside the range of the allowable output fluctuation range.
An abnormality detection method for a prime mover. In the motor | power_engine abnormality detection method of Claim 5,
In the correction step, the apparent output fluctuation that is delayed by a delay time of the output from the output meter with respect to the output from the tachometer is subtracted from the output output from the output meter.
An abnormality detection method for a prime mover. In the motor abnormality detection method according to claim 5 or 6,
In the abnormality determination step, an output fluctuation calculation step in which a difference between the output corrected in the correction step and a reference output with respect to the output detected by the output meter is a fluctuation of the output,
An abnormality detection method for a prime mover, characterized by being executed. In the motor abnormality detection method according to claim 4 or 7,
In the output fluctuation calculation step, a reference output that is an output obtained using an output change rate allowed when the prime mover and the generator are in normal operation is used as the reference output.
An abnormality detection method for a prime mover. In the control device of the prime mover mechanically connected to the generator,
An abnormality determining unit that determines whether or not the prime mover is abnormal according to whether or not a fluctuation range of the output of the generator detected by an output meter is out of a range of an allowable output fluctuation range;
One of the permissible output fluctuation range that is a determination criterion in the abnormality determination unit and the output detected by the output meter that is a determination target in the abnormality determination unit is detected by the revolution meter. A correction unit that corrects using the rotational speed of one of the generator and the prime mover;
When the abnormality determination unit determines that the prime mover is abnormal, it outputs a trip signal to an operation unit that can trip the prime mover, and a trip signal output unit that trips the prime mover;
A motor control apparatus comprising: The motor control device according to claim 9,
The correction unit uses the one rotation number to determine a rotation speed fluctuation range for the rotation speed fluctuation range of the rotation speed, and the allowable output fluctuation width increases as the rotation speed fluctuation width increases. An allowable fluctuation range correction unit that corrects the allowable output fluctuation range so as to increase,
The abnormality determination unit determines whether the prime mover is abnormal depending on whether the fluctuation range of the output detected by the output meter is outside the range of the allowable output fluctuation range corrected by the correction unit. A control apparatus for a prime mover characterized by determining whether or not. The motor control device according to claim 10,
The rotation speed fluctuation range calculation unit
Upper reference rotation which is a rotation speed obtained using a rotation speed reduction rate allowed when the prime mover and the generator are operating normally when the rotation speed is lower than the rated rotation speed An upper reference rotational speed calculation unit for obtaining a number;
The lower reference rotational speed, which is the rotational speed obtained using the rotational speed increase rate allowed when the prime mover and the generator are operating normally when the rotational speed increases when the rotational speed is equal to or lower than the rated rotational speed. A lower reference rotational speed calculation unit for obtaining a lower reference rotational speed at the same time as the upper reference rotational speed;
A deviation calculating section for obtaining a difference between the upper reference rotation speed and the lower reference rotation speed and outputting the difference as the rotation speed fluctuation range;
A control apparatus for a prime mover. The motor control device according to claim 10 or 11,
The abnormality determination unit includes an output fluctuation calculation unit that sets a difference between the output detected by the output meter and a reference output with respect to the output as a fluctuation of the output.
A control device for a prime mover. The motor control device according to claim 9,
The correction unit is
Using the one rotational speed, the rotational speed change rate that is the rate of change of the rotational speed per unit time, and the moment of inertia of the rotating system in the prime mover and the generator, the apparent output fluctuation of the prime mover An apparent output fluctuation calculation unit for obtaining
A value obtained by subtracting the apparent output fluctuation from the output of the generator detected by the output meter, an output calculation unit that outputs the corrected value,
Have
The abnormality determination unit determines whether the prime mover is abnormal depending on whether or not the fluctuation range of the output corrected by the correction unit is outside the range of the allowable output fluctuation range.
A control device for a prime mover. The motor control device according to claim 13,
The correction unit includes a delay time adjustment unit that delays the apparent output fluctuation input to the output calculation unit by a delay time of the output from the output meter with respect to the output from the tachometer.
A control device for a prime mover. The motor control device according to claim 13 or 14,
The abnormality determination unit includes an output fluctuation calculation unit that sets a difference between the output corrected by the correction unit and a reference output with respect to the output detected by the output meter as a fluctuation of the output.
A control device for a prime mover. The motor control apparatus according to claim 12 or 15,
The output fluctuation calculating unit uses, as the reference output, a reference output that is an output obtained using an output change rate allowed when the prime mover and the generator are in normal operation.
A control device for a prime mover. A controller for a prime mover according to any one of claims 9 to 16,
The prime mover;
The generator;
The operation unit;
A power plant characterized by comprising:

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