Method for monitoring and judging speed regulator of water-turbine generator set of pumped storage power station

Abstract

The invention discloses a method for monitoring and judging a speed regulator of a water-turbine generator set of a pumped storage power station, which comprises the following steps of: S01, acquiring data, respectively installing a first speed measurement probe and a second speed measurement probe on two sides of a fluted disc of a water-turbine generator, and leading out a PT speed measurement probe from a transformer of the water-turbine generator set; s02, data processing is carried out, deviation values of the output data, collected in the S01, of the three channels are calculated in pairs, and the obtained three deviation values are compared with set deviation threshold values; and S03, state judgment: PT speed measurement is introduced in the monitoring judgment method, a monitoring source of the speed regulator is added to fluted disc frequency measurement and residual voltage frequency measurement, the state and fault of the speed regulator are judged according to the results of the fluted disc frequency measurement and the residual voltage frequency measurement, accurate unit operation information is obtained, meanwhile, the fluted disc frequency measurement and the residual voltage frequency measurement are compared, and the fault of the speed regulator is judged. Logic optimization is carried out by applying a difference value method, accurate state monitoring of the hydro-generator speed regulator is achieved, and the situation that a single speed measurement source causes false triggering and tripping is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of governor monitoring in pumped - storage power stations, and particularly to a method for monitoring and judging the governor of a hydro - generator set in a pumped - storage power station. Background Art

[0002] As an important part of a pumped - storage power station, the hydro - generator set mainly plays the role of power generation and pumping. During the peak period of power demand, the pumped - storage power station generates electricity by releasing the water in the upper reservoir to meet the power demand during peak hours. The hydro - generator converts the gravitational potential energy of water into electrical energy to provide a stable power output. During the low - demand period of power, the pumped - storage power station uses the excess electrical energy to pump the water from the lower reservoir to the upper reservoir for storage. At this time, the hydro - generator operates as a pump, pumping water from the lower reservoir to the upper reservoir to prepare for subsequent power generation. At the same time, the pumped - storage power station can flexibly adjust the water volume in the upper and lower reservoirs, quickly respond to the change of the grid load within several hours or even dozens of minutes, flatten the sharp peak of the power demand curve, and ensure the smooth operation of the power grid at all times.

[0003] As a part of the hydro - generator set, the governor plays an important role. The governor can monitor the rotational speed of the hydro - generator, the grid frequency, the water flow rate, etc. By monitoring these parameters, the operating state of the water turbine can be understood in real time and adjusted as needed. The governor compares the actual rotational speed of the water turbine with the rated frequency of the power grid. If the actual rotational speed is lower than the rated frequency, the governor will increase the water flow rate to increase the rotational speed of the water turbine; otherwise, it will reduce the water flow rate to lower the rotational speed. This automatic adjustment mechanism ensures that the rotational speed of the water turbine always remains within the rated range, thus maintaining the stability of the grid frequency.

[0004] Currently, the monitoring of the governor is achieved through the results of the speed - measuring probe installed on the gear disk of the hydro - generator. This method is also called gear - disk frequency measurement monitoring. However, during the long - term operation of the unit, the quality of the gear - disk speed - measuring probe will change with the harsh operating environment. Since oil mist is generated in the waterwheel chamber and the oil mist will leak into the gap of the speed - measuring probe, causing certain physical interference, resulting in errors in the measurement results. In this case, using the measurement results as the basis for judging the monitoring results will lead to single - point tripping during the operation of the hydro - generator. Summary of the Invention

[0005] To overcome the above problems, the objective of the present invention is to provide a monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit. This monitoring and judgment method introduces PT speed measurement, also known as residual voltage frequency measurement, on the basis of the current monitoring method for the governor of a hydro-generator. In this way, the monitoring sources of the governor are increased to tooth disc frequency measurement and residual voltage frequency measurement. According to the results of tooth disc frequency measurement and residual voltage frequency measurement, the state and faults of the governor are judged, accurate unit operation information can be obtained, and at the same time, the tooth disc frequency measurement and residual voltage frequency measurement are compared, and the difference method is used for logic optimization to achieve precise monitoring of the state of the governor of a hydro-generator and avoid the occurrence of false trip caused by a single speed measurement source.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit, comprising the following steps:

[0008] S01: Data acquisition. Install a first speed measurement probe and a second speed measurement probe on both sides of the tooth disc of the hydro-generator, and lead out a PT speed measurement probe from the transformer of the hydro-generating unit. The output of the first speed measurement probe is , and the output of the second speed measurement probe is , and the output of the PT speed measurement probe is ;

[0009] S02: Data processing. Calculate the deviation values pairwise for the output data of the three channels collected in S01 to obtain , , :

[0010] ,

[0011] ,

[0012] ,

[0013] Compare the three obtained deviation values with the set deviation threshold respectively;

[0014] S03: State judgment,

[0015] State 1: If any two-way deviation is less than the deviation threshold, that is, , , , then the hydro-generating unit is in a normal operation state. At this time, the main signal of the hydro-generating unit selects , and there is no alarm information,

[0016] State 2: If only the deviation between the first speed measurement probe and the second speed measurement probe is greater than the deviation threshold, that is, , , , at this time, the main signal of the hydro-generator unit is selected 、 the larger value among them, and report the frequency deviation warning information,

[0017] Status 3: If 、 、 if two of them are greater than and the remaining one is less than , it is necessary to further judge by combining the results of the deviation thresholds of the gear speed measurement probe and the PT speed measurement probe,

[0018] Status 4: If the deviation of any two paths is greater than the deviation threshold, that is , , , at this time, the main signal of the hydro-generator unit is selected 、 、 the maximum value among them, and report the frequency deviation warning information.

[0019] As a further description of the present invention, the specific judgment steps of Status 3 in S03 are as follows:

[0020] If , that is, there is no deviation in the PT speed measurement probe in this state, and there is a deviation in the gear speed measurement probe. At this time, the main signal of the hydro-generator unit is selected , and report the frequency deviation warning information;

[0021] If , that is, there is a deviation in the PT speed measurement probe in this state. At this time, the main signal of the hydro-generator unit is selected 、 the larger value among them. If is less than or equal to the standard frequency value of the PT speed measurement probe, there is no alarm information. If is greater than the standard frequency value of the PT speed measurement probe, report the frequency deviation warning information.

[0022] As a further description of the present invention, fault judgment can also be carried out according to the status in S03. Among them, the PT fault is recorded as FG1, the first speed measurement probe fault is recorded as FG2, and the second speed measurement probe fault is recorded as FG3. The fault judgment result is:

[0023] Fault 1: The PT speed measurement probe fails, and the results of the other two gear speed measurement probes are normal. Then the main signal selects the larger value of the two gear speed measurement probes and reports the small fault FG1 of signal loss;

[0024] Fault 2: If one of the toothed disk speed measurement probes fails, and the PT speed measurement probe and the other toothed disk speed measurement probe are normal, the main signal selects the larger value between the PT speed measurement and the normal toothed disk speed measurement probe, and reports the minor fault of probe signal loss FG2 or FG3;

[0025] Fault 3: If the PT speed measurement probe is normal and both toothed disk speed measurement probes fail, the main signal selects the signal of the PT speed measurement probe and reports the minor faults of signal loss FG2 and FG3;

[0026] Fault 4: If the PT speed measurement probe and one of the two toothed disk speed measurement probes fail, the main signal selects the signal of the non-faulty probe among the two toothed disk speed measurement probes, and reports the minor faults of signal loss FG1 and FG2, or FG1 and FG3;

[0027] Fault 5: If the PT speed measurement probe and both toothed disk speed measurement probes fail, it reports the major fault of frequency loss FG.

[0028] As a further description of the present invention, the first speed measurement probe and the second speed measurement probe respectively installed on both sides of the toothed disk of the hydro-generator in S01 are the main speed measurement probes. Backup speed measurement probes are also installed on both sides of the toothed disk of the hydro-generator. The backup speed measurement probes include a third speed measurement probe and a fourth speed measurement probe. The installation position of the third speed measurement probe is the same as that of the first speed measurement probe, and the installation position of the fourth speed measurement probe is the same as that of the second speed measurement probe.

[0029] As a further description of the present invention, both the main speed measurement probe and the backup speed measurement probe are installed at a position 3 mm away from the large shaft of the hydro-generator unit.

[0030] As a further description of the present invention, the data obtained in the data processing stage in S02 needs to be delayed for 0.3 s before being processed.

[0031] As a further description of the present invention, the data of both the main speed measurement probe and the backup speed measurement probe are uploaded to the background system for monitoring.

[0032] The beneficial effects of the present invention:

[0033] A monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit includes the following steps: S01: Data acquisition, S02: Data processing, S03: Status judgment. In the data acquisition stage, PT speed measurement is introduced. PT speed measurement is also known as residual voltage frequency measurement. In this way, the monitoring sources of the governor are increased to tooth disc frequency measurement and residual voltage frequency measurement. By judging the governor's status and faults based on the results of tooth disc frequency measurement and residual voltage frequency measurement, accurate unit operation information can be obtained. In the data processing stage and the status monitoring stage, the tooth disc frequency measurement and the residual voltage frequency measurement are compared simultaneously, and the difference method is used for logical optimization to achieve precise monitoring of the status of the hydro-generator governor and avoid false trips caused by a single speed measurement source.

[0034] A monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit according to the present invention can further implement fault judgment based on the status in S03. In this way, during the monitoring process, the faults of the hydro-generating unit can be detected in a timely manner and warning information can be sent, and relevant staff can handle it in a timely manner to ensure the normal and stable operation of the hydro-generating unit.

[0035] A monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit according to the present invention uses a primary speed measurement probe and a backup speed measurement probe in the data acquisition stage. During the actual monitoring process, when the primary speed measurement probe fails, the data of the backup speed measurement probe can be used for monitoring. The setting of such two groups of speed measurement probes further ensures the reliability of the governor monitoring results.

[0036] A monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit according to the present invention requires the data obtained in the data processing stage to be processed after a 0.3s delay. This method can prevent errors in the monitoring results caused by jitter generated by factors such as the vibration of the hydro-generating unit and the shaking of the equipment cabinet during the signal transmission process, ensure the accuracy of the monitoring results, and achieve precise monitoring. Description of the Drawings

[0037] Figure 1 is a flowchart of a monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit proposed by the present invention;

[0038] Figure 2 is a flowchart of the status judgment of a monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit proposed by the present invention;

[0039] Figure 3 is a fault judgment result diagram of a monitoring and judgment method for the governor of a pumped-storage power station's hydro-generating unit proposed by the present invention. Detailed Embodiments

[0040] To make the above objects, features and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the accompanying drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the scope of protection of the present invention.

[0041] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0042] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is separate or selectively mutually exclusive with other embodiments.

[0043] The present invention will be described in detail in conjunction with the schematic diagrams. When detailing the embodiments of the present invention, for the convenience of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0044] Meanwhile, in the description of the present invention, it should be noted that the orientation or positional relationships indicated by terms such as "upper, lower, inner and outer" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] Unless otherwise clearly defined and limited in the present invention, the terms "mounted, connected, and coupled" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may also be a mechanical connection, an electrical connection or a direct connection, or may be indirectly connected through an intermediate medium, or may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] As Figures 1 to 3 shown, it shows the specific embodiments of the present invention:

[0047] Embodiment 1

[0048] A monitoring and judgment method for the governor of a pumped - storage power station hydro - generator set includes the following steps:

[0049] S01: Data acquisition. Install a first speed - measuring probe and a second speed - measuring probe on both sides of the gear disk of the hydro - generator, and lead out a PT speed - measuring probe from the transformer of the hydro - generator set. The output of the first speed - measuring probe is and the output of the second speed - measuring probe is and the output of the PT speed - measuring probe is ;

[0050] S02: Data processing. Calculate the deviation values pairwise for the output data of the three channels collected in S01 to obtain , , :

[0051] ,

[0052] ,

[0053] ,

[0054] Compare the three obtained deviation values with the set deviation threshold respectively;

[0055] S03: Status judgment,

[0056] Status 1: If the deviation of any two channels is less than the deviation threshold, that is , , , then the hydro - generator set is in a normal operation state. At this time, the main signal of the hydro - generator set selects , and there is no alarm information.

[0057] Status 2: If only the deviation between the first speed - measuring probe and the second speed - measuring probe is greater than the deviation threshold, that is , , , at this time, the main signal of the hydro - generator set selects the larger value of and , and reports a frequency deviation warning message.

[0058] Status 3: If , , where two of them are greater than , and the remaining one is less than , then it is necessary to further judge by combining the results of the gear - disk speed - measuring probe and the PT speed - measuring probe with the deviation threshold.

[0059] Status 4: If the deviation between any two channels is greater than the deviation threshold, that is , , , at this time, the main signal selection of the hydro-generating unit , , The maximum value in is reported as a frequency deviation warning message.

[0060] In this embodiment, as Figure 1 shown, the monitoring and judgment method of the governor of the pumped-storage power station's hydro-generating unit realizes monitoring through three parts: S01: data acquisition, S02: data processing, and S03: status judgment. Among them, PT speed measurement is introduced in the data acquisition stage. PT speed measurement is also called residual voltage frequency measurement. In this way, the monitoring sources of the governor are increased to tooth disc frequency measurement and residual voltage frequency measurement. According to the results of tooth disc frequency measurement and residual voltage frequency measurement, the status and faults of the governor are judged, and accurate unit operation information can be obtained. In the data processing stage and the status judgment and monitoring stage, the tooth disc frequency measurement and the residual voltage frequency measurement are compared at the same time, and the difference method is used for logical optimization to realize the precise monitoring of the status of the hydro-generator governor and avoid the occurrence of mis-triggered trip caused by a single speed measurement source.

[0061] As a further description of the present invention, the specific judgment steps of status 3 in S03 are as follows:

[0062] If , that is, there is no deviation in the PT speed measurement probe in this state, and there is a deviation in the tooth disc speed measurement probe. At this time, the main signal selection of the hydro-generating unit is reported as a frequency deviation warning message;

[0063] If , that is, there is a deviation in the PT speed measurement probe in this state. At this time, the main signal selection of the hydro-generating unit , The larger value in. Among them, if is less than or equal to the standard frequency value of the PT speed measurement probe, there is no alarm message. If is greater than the standard frequency value of the PT speed measurement probe, a frequency deviation warning message is reported.

[0064] In this embodiment, as Figure 2 shown, the process of status judgment is judged according to different measurement results, and the selection of the main signal is clearly explained during the monitoring process, so that the true state of the hydro-generator governor can be obtained timely and accurately.

[0065] Embodiment 2

[0066] On the basis of the above-mentioned Embodiment 1, fault judgment can be further realized according to the status. Therefore, this Embodiment 2 is proposed.

[0067] Specifically, fault judgment can also be performed according to the status in S03. Among them, the PT fault is recorded as FG1, the fault of the first speed measurement probe is recorded as FG2, and the fault of the second speed measurement probe is recorded as FG3. The fault judgment results are as follows:

[0068] Fault 1: The PT speed measurement probe fails, and the results of the other two gear speed measurement probes are normal. Then the main signal selects the larger value of the two gear speed measurement probes, and reports a minor fault of signal loss FG1.

[0069] Fault 2: One of the gear speed measurement probes fails, and the PT speed measurement probe and the other gear speed measurement probe have normal results. Then the main signal selects the larger value of the PT speed measurement and the normal gear speed measurement probe, and reports a minor fault of probe signal loss FG2 or FG3.

[0070] Fault 3: The PT speed measurement probe is normal, and the two gear speed measurement probes fail. Then the main signal selects the signal of the PT speed measurement probe, and reports minor faults of signal loss FG2 and FG3.

[0071] Fault 4: The PT speed measurement probe and one of the two gear speed measurement probes fail. Then the main signal selects the signal of the non-faulty probe among the two gear speed measurement probes, and reports minor faults of signal loss FG1 and FG2, or FG1 and FG3.

[0072] Fault 5: The PT speed measurement probe and the two gear speed measurement probes both fail, then report a major fault of frequency loss FG.

[0073] In this embodiment, as Figure 3 shown, this fault judgment process can timely detect the fault situation of the hydro-generator unit during the monitoring process and send early warning information, so that relevant staff can handle it in time to ensure the normal and stable operation of the hydro-generator unit.

[0074] In the actual application of this method, on the basis of the existing scheme, the relevant parameter configuration and logic table are as follows:

[0075] Table 1 Parameter Configuration Table

[0076]

[0077] Table 2 Logic Table

[0078]

[0079] Embodiment 3

[0080] Specifically, the first speed measurement probe and the second speed measurement probe respectively installed on both sides of the water turbine generator tooth disc in S01 are the primary speed measurement probes. Backup speed measurement probes are also installed on both sides of the water turbine generator tooth disc. The backup speed measurement probes include a third speed measurement probe and a fourth speed measurement probe. The installation position of the third speed measurement probe is the same as that of the first speed measurement probe, and the installation position of the fourth speed measurement probe is the same as that of the second speed measurement probe.

[0081] Specifically, both the primary speed measurement probes and the backup speed measurement probes are installed at a position 3 mm away from the large shaft of the water turbine generator set.

[0082] Specifically, the data of both the primary speed measurement probes and the backup speed measurement probes are uploaded to the background system for monitoring.

[0083] In this embodiment, the primary speed measurement probes and the backup speed measurement probes are used in the data acquisition stage. During the actual monitoring process, when a primary speed measurement probe fails, the data of the backup speed measurement probe can be used for monitoring. The setting of such two sets of speed measurement probes further ensures the reliability of the monitoring results of the governor.

[0084] Specifically, the data obtained in the data processing stage in S02 needs to be delayed by 0.3 s before being processed.

[0085] In this embodiment, the data obtained in the data processing stage needs to be delayed by 0.3 s before being processed. Adopting this method can prevent errors in the monitoring results caused by jitter generated by other factors such as the vibration of the hydroelectric generating unit and the shaking of the equipment cabinet during the signal transmission process, ensure the accuracy of the monitoring results, and achieve precise monitoring.

[0086] Embodiment 4

[0087] The application situation of the generator set governor monitoring and judgment method involved in the above embodiment in an actual pumped storage power station is as follows: During the pumping steady-state operation of Unit 2 of a pumped storage power station on July 14, 2024, an emergency shutdown occurred due to the action of electrical secondary over-speed.

[0088] Before the failure occurred, its operating mode was as follows: The 500 kV line was operating in normal closed-loop, all 500 kV switchgears were normally closed, the 1-4 main transformers were in operation, the plant electricity was operating in normal sectionalization, and Units 1, 2, 3, and 4 were in pumping operation.

[0089] After the failure occurred, the operating mode was as follows: The 500 kV line was operating in normal closed-loop, all 500 kV switchgears were normally closed, the 1-4 main transformers were in operation, the plant electricity was operating in normal sectionalization, Units 1, 3, and 4 were in pumping operation, and Unit 2 had an emergency shutdown due to water turbine protection.

[0090] The process record of this fault event is as follows:

[0091] 04:11:36 The speed of Unit 2 >= 1.10Vn: RV9 = 1 (primary electrical overspeed)

[0092] 04:11:36 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0

[0093] 04:11:36 The speed of Unit 2 >= 1.10Vn: RV9 = 1 (primary electrical overspeed) is reset

[0094] 04:11:36 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0 is reset

[0095] 04:11:37 The speed of Unit 2 >= 1.10Vn: RV9 = 1 (primary electrical overspeed)

[0096] 04:11:38 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0

[0097] 04:11:38 The speed of Unit 2 >= 1.10Vn: RV9 = 1 (primary electrical overspeed) is reset

[0098] 04:11:38 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0 is reset

[0099] 04:11:39 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0

[0100] 04:11:42 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0 is reset

[0101] 04:28:06 The speed of Unit 2 >= 1.1Vn: RV9 = 1 (primary electrical overspeed)

[0102] 04:28:06 The speed of Unit 2 >= 1.15Vn: RV10 = 1 (secondary electrical overspeed)

[0103] 04:28:06 The main speed measuring device TADTN of Unit 2 alarms: RD129N = 0

[0104] 04:28:06 The accident pressure regulating valve AA891 of the governor of Unit 2 is reset and returned

[0105] 04:28:06 The accident pressure regulating valve AA891 of the governor of Unit 2 operates

[0106] 04:28:06 The hydraulic protection emergency shutdown of Unit 2 operates

[0107] At 04:28:06, the solenoid valve AA803 of the governor of Unit 2 was energized and closed, and the operation was triggered.

[0108] At 04:28:07, the emergency shutdown button was triggered, and the emergency shutdown operation of Unit 2 was carried out.

[0109] At 04:28:18, the closing position of GCB02 = 2BAA60GS101 of Unit 2 was restored;

[0110] At 04:28:18, GCB02 = 2BAA60GS101 of Unit 2 was in the open position;

[0111] At 04:39:25, the emergency shutdown operation of Unit 2 was successful (the process was self-started).

[0112] According to the fault situation that occurred, the handling process of the maintenance personnel was as follows:

[0113] Situation sorting:

[0114] Checking the monitoring curve of the speed of Unit 2, it was confirmed that the analog quantity of the speed exceeded 115% before the unit tripped.

[0115] Combined with the monitoring briefing: when the speed of Unit 2 >= 1.1Vn, RV9 = 1 (primary electrical overspeed) and when the speed of Unit 2 >= 1.15Vn, RV10 = 1 (secondary electrical overspeed) are triggered. It can be judged that the RV09 and RV10 relays in the electric governor cabinet are triggered, indicating that TADTN also judges that the speed at that time exceeded 115%. Among them, the main TADT has two speed measurement probes, and the deviation value is less than 4%. The CS044 speed measurement probe is selected. If the direct deviation of the measured speeds of the two speed measurement probes exceeds 4%, the speed measurement module TADT will alarm and the value of the CS044 speed measurement probe will be compared with the value of CS043, and the larger value will be taken; when the electrical overspeed of the speed measurement device is triggered, Unit 2 reports an alarm for the main speed measurement device TADTN; the frequency of Unit 2 in the monitoring curve has no fluctuation at 50HZ. There are a total of 6 probes for disk speed measurement, one is sent to the main UPC of the governor, one is sent to the standby UPC, two are sent to the main TADT device, and two are sent to the standby TADT device.

[0116] Analyzing the possible reasons for the above phenomena:

[0117] 1. The actual speed of Unit 2 at the site increased to 115%, resulting in the secondary electrical overspeed being triggered and the unit undergoing an emergency shutdown;

[0118] 2. The terminals of the speed measurement circuit were loose, resulting in a sudden change in the measured speed value;

[0119] 3. The main speed measurement module TADTN malfunctioned;

[0120] 4. The speed measurement probe malfunctioned.

[0121] 5. The distance between the speed measurement probe and the gear disk changes.

[0122] Cause analysis:

[0123] 1. First, after the accident, the unit's mechanical overspeed flyball and the gear disk speed measurement probe were inspected on-site. It was found that the overspeed flyball (operating at 110%) did not operate, the gear disk speed measurement probe was not damaged and not loose; there was no speed-related alarm in the governor UPC (the UPC speed signal is taken from the residual voltage frequency measurement in one way, from the network frequency in one way, and from the gear disk speed measurement probe in one way), and the frequency curve had no fluctuation at 50HZ; there were also no speed-related alarm signals on the excitation and protection panels. Based on the above analysis, it is considered that the actual speed of Unit 2 was normal and not overspeed, so Cause 1 can be excluded at this time.

[0124] 2. Since both TADT and the monitoring received abnormal speed signals, it means that the problem may lie in the speed measurement circuit of the main TADT. After arriving at the site, we inspected the relevant circuit wiring of the governor electrical cabinet, the monitoring panel cabinet, and the gear disk speed measurement probe. The wiring, relays, and TADT module plugs were all not loose, so Cause 2 can be excluded at this time.

[0125] 3. Considering the relevant alarm signals and the actual situation, Causes 3 and 4 are considered together. According to the speed situation read by the monitoring from TADTN at that time, and the alarm and speed node output situation of the TADTN module itself, the TADTN module did indeed read abnormal speed, and output speed nodes (the RV09 and RV10 relays operated) and abnormal speed analog signals; according to the working principle of the equipment, the possible reasons for the TADT to alarm are only the loss of the speed signal or the direct deviation of the measured speeds of the two speed measurement probes exceeding 4%. The actual situation on-site is that the speed signal was not lost. Therefore, it can be judged that before the overspeed operation, the direct deviation of the measured speeds of the two speed measurement probes of the TADTN module exceeded 4%, indicating that one of the speed measurement probes is abnormal, or the speed measurement channel of the TADT module is abnormal, resulting in a situation where the measured speed is too high.

[0126] 4. Therefore, it is necessary to consider from the source of the speed measurement probe and the TADT module; first, consider replacing the two speed measurement probes of the main TADT and then conduct tests to confirm that the device is okay.

[0127] Determine the fault point:

[0128] On-site, the two speed measurement probes of the main TADT were replaced, and then the no-load test of Unit 2 was carried out. During the test, the unit speed was normal without fluctuations, and there were no relevant alarms in the main TADT module. Therefore, it can be confirmed that the speed measurement probe of the main TADT was damaged, resulting in an excessively high measured value of the unit speed, the RV10 relay operated, and the electrical secondary overspeed operation led to an emergency shutdown.

[0129] Treatment steps:

[0130] 1. Switch the main TADT to the standby TADT for operation, and first pump water to start the machine to ensure the pumping load of the unit for the grid dispatching;

[0131] 2. Check whether the speed measurement circuit of the electric governor cabinet and the relevant circuits of the monitoring feedback are normal;

[0132] 3. Replace the speed measurement probe of the main TADT and conduct a no-load test of the unit for inspection.

[0133] Analysis of the cause of the fault

[0134] The measurement accuracy of the speed measurement probe of the main TADT deviated due to long operation time or component quality problems.

[0135] During the pumping operation of Unit 2, one of the speed measurement probes of the main TADT failed, and the measured speed value was on the high side. Also, because the two speed measurement probes of the main TADT take the larger value as the standard, the main TADT module judged that the unit was overspeed and output that the speed of Unit 2 >= 1.1Vn: RV9 = 1 (primary electrical overspeed), the speed of Unit 2 >= 1.15Vn: RV10 = 1 (secondary electrical overspeed) operated (the RV09 and RV10 relays operated). The primary electrical overspeed is connected in series with the position switch of the mechanical overspeed of the gear disc flyweight. Since the mechanical overspeed of the gear disc flyweight did not operate, the primary electrical overspeed did not trip the unit. When the secondary electrical overspeed operated, the unit had an emergency shutdown.

[0136] The occurrence of this fault can be avoided by using the governor monitoring method of the above embodiment.

[0137] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art, various changes can also be made without departing from the purpose of the present invention.

[0138] Many other changes and modifications can be made without departing from the concept and scope of the present invention. It should be understood that the present invention is not limited to a specific embodiment, and the scope of the present invention is defined by the appended claims.

Claims

1. A monitoring and judgment method for the governor of a pumped-storage power station hydro-generator unit, characterized in that, It includes the following steps: S01: Data acquisition. Install a first speed measurement probe and a second speed measurement probe on both sides of the gear disk of the hydrogenerator, and lead out a PT speed measurement probe from the transformer of the hydrogenerator unit. The output of the first speed measurement probe is , the output of the second speed measurement probe is , and the output of the PT speed measurement probe is ; S02: Data processing, calculating the deviation values pairwise for the output data of the three channels collected in S01 to obtain , , : ， , , The three obtained deviation values are respectively compared with the set deviation threshold for comparison; S03: State judgment, Status 1: If the deviation between any two paths is less than the deviation threshold, i.e., , , , then the hydro-generator unit is in normal operation. At this time, the main signal of the hydro-generator unit is selected , and there is no alarm message. Status 2: If the deviation between only the first speed measurement probe and the second speed measurement probe is greater than the deviation threshold, i.e., , , , at this time, the main signal of the hydro-generator unit selects , the larger value among them, and reports the frequency deviation warning information. Status 3: If , , where two of them are greater than , and the remaining one is less than , then it is necessary to further judge by combining the results of the sprocket speed measurement probe, the PT speed measurement probe and the deviation threshold. Status 4: If the deviation between any two channels is greater than the deviation threshold, i.e., , , , at this time, the main signal of the hydro-generating unit selects , , the maximum value among them, and reports the frequency deviation warning information.

2. A monitoring and judgment method for a governor of a water turbine generator set in a pumped storage power station according to claim 1, characterized in that, The specific judgment steps for state 3 in S03 are as follows: If , that is, the PT speed measurement probe has no deviation and the toothed disk speed measurement probe has deviation in this state. At this time, the main signal of the hydro-generator unit is selected , and a frequency deviation warning message is reported; If , that is, there is a deviation in the PT speed measurement probe in this state. At this time, the main signal of the hydro-generator unit selects , the larger value. Among them, if is less than or equal to the standard frequency value of the PT speed measurement probe, there is no alarm message. If is greater than the standard frequency value of the PT speed measurement probe, a frequency deviation warning message is reported.

3. A monitoring and judgment method for a governor of a pumped-storage power station hydro-generating unit according to claim 1, characterized in that Fault judgment can also be carried out according to the state in S03, where the PT fault is recorded as FG1, the fault of the first speed measurement probe is recorded as FG2, and the fault of the second speed measurement probe is recorded as FG3. The fault judgment results are: Fault 1: The PT speed measurement probe fails, and the results of the other two gear speed measurement probes are normal. Then the main signal selects the larger value of the two gear disk speed measurement probes and reports the small fault FG1 of signal loss; Fault 2: One of the gear disk speed measurement probes fails, and the PT speed measurement probe and the other gear disk speed measurement probe are normal. Then the main signal selects the larger value of the PT speed measurement and the normal gear disk speed measurement probe and reports the small fault FG2 or FG3 of probe signal loss; Fault 3: The PT speed measurement probe is normal, and the two gear disk speed measurement probes fail. Then the main signal selects the signal of the PT speed measurement probe and reports the small fault FG2 and FG3 of signal loss; Fault 4: The PT speed measurement probe and one of the two gear disk speed measurement probes fail. Then the main signal selects the signal of the non-fault probe among the two gear disk speed measurement probes and reports the small fault FG1 and FG2, or FG1 and FG3 of signal loss; Fault 5: The PT speed measurement probe and the two gear disk speed measurement probes all fail, then report the large fault FG of frequency loss.

4. A monitoring and judgment method for the governor of a pumped-storage power station hydro-generating unit according to claim 1, characterized in that The first speed measurement probe and the second speed measurement probe respectively installed on both sides of the water turbine generator gear disk in S01 are the main speed measurement probes. Backup speed measurement probes are also installed on both sides of the water turbine generator gear disk. The backup speed measurement probes include a third speed measurement probe and a fourth speed measurement probe. The installation position of the third speed measurement probe is the same as that of the first speed measurement probe, and the installation position of the fourth speed measurement probe is the same as that of the second speed measurement probe.

5. A monitoring and judgment method for the governor of a pumped-storage power station hydro-generating unit according to claim 4, characterized in that Both the main speed measurement probe and the backup speed measurement probe are installed at a position 3 mm away from the large shaft of the water turbine generator set.

6. A monitoring and judgment method for a governor of a pumped-storage power station hydro-generating unit according to claim 1, characterized in that, The data obtained in the data processing stage in S02 needs to be delayed for 0.3 s before being processed.

7. A monitoring and judgment method for a governor of a pumped-storage power station hydro-generator set according to claim 4, characterized in that The data of both the main speed measurement probe and the backup speed measurement probe are uploaded to the background system for monitoring.

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