Water-turbine generator set vibration protection method based on power criterion and isolator

Abstract

The invention discloses a hydroelectric generating set vibration protection method based on a power criterion and an isolator. The hydroelectric generating set vibration protection method comprises the steps that a set LCU cabinet and a set vibration protection cabinet are connected through a set active power sending-out circuit; inputting a signal output by the unit into an isolator at a preset mounting position, and transmitting and outputting an isolated signal to obtain an isolation result between the input and output of the isolator and a power supply; acquiring real-time active power of the unit, and judging whether the real-time active power is located in a preset unstable operation region or not to obtain a judgment result; according to the judgment result, a vibration protection constant value corresponding to the real-time active power is switched to monitor the vibration state of the unit to obtain a vibration state monitoring result; and triggering a corresponding alarm or trip mechanism according to the monitoring result of the vibration state. According to the method, the situation of false triggering and tripping under the unstable working condition is effectively avoided, the reliability and safety of the system are improved, and stable operation of the hydropower station is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of hydro-generator sets, and in particular to a hydro-generator set swing protection method based on power criterion and isolator. Background Art

[0002] The hydro-turbine generator set swing protection system is used to monitor the vibration and swing of the unit, and issue an alarm or shutdown command when it exceeds the preset threshold. When the current system operates in the unstable operating area, it is unable to determine whether the unit is in a safe state due to the lack of access to parameters such as active power, resulting in false operation.

[0003] The existing swing protection system uses the early TN6000 system designed by Beijing Huake Tongan Company, which does not take into account the key parameter of the unit's active power, resulting in false alarms or wrong shutdowns in unstable operating areas. The existing swing protection system cannot automatically adjust the protection setting according to the actual operating conditions of the hydro-turbine generator set, resulting in false alarms or wrong shutdowns in the system under specific operating conditions, affecting the safety and reliability of the unit. When judging the operating conditions of the unit, the existing system lacks an effective method to distinguish the vibration zone and non-vibration zone of the unit in real time, resulting in the failure to adjust the protection measures in time when the unit faces different loads or operating conditions, thereby increasing the risk of failure. Analog signals (such as the unit's active power) are introduced to distinguish between vibration zones and non-vibration zones, but they are easily affected by external interference during the transmission process, which may cause signal distortion or misinterpretation, further affecting the judgment and response capabilities of the swing protection system. The current hydro-turbine generator set swing protection system lacks effective isolation and protection measures during the transmission of analog signals, resulting in insufficient stability and reliability of the signal during transmission, which in turn affects the performance of the overall system. The active power signal of the unit is easily interfered during transmission, resulting in inaccurate signals, which in turn affects the accuracy and reliability of the swing protection system. The swing protection system uses a single protection setting and cannot distinguish between stable and unstable operating areas, resulting in the erroneous sending of trip signals when the unit is in an unstable operating condition.

[0004] When using 4-20mA current signal transmission, it is susceptible to electromagnetic interference during long-distance transmission; the swing protection system is not connected to parameters such as the unit's active power, and cannot determine whether the unit is operating in a stable operating area. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, the present invention proposes a method for swing protection of a hydro-turbine generator set based on power criteria and isolators, which improves the transmission stability of the swing protection system for analog signals, thereby achieving accurate judgment of the operating conditions of the hydro-turbine generator set and automatic adjustment of protection settings, reducing the risks of false alarms and incorrect shutdowns, and improving the safety and reliability of the unit.

[0007] Another object of the present invention is to provide a hydro-generator set swing protection system based on power criteria and isolators.

[0008] To achieve the above object, the present invention proposes a method for protecting a hydro-generator set from oscillation based on power criteria and an isolator, comprising:

[0009] Connect the unit LCU cabinet and the unit vibration protection cabinet through the unit active power transmission line;

[0010] Input the signal output by the unit into the isolator at a preset installation position, and transmit the output isolated signal to obtain the isolation result between the input and output of the isolator and the power supply; wherein the preset installation position is the position on the active power transmission line of the unit;

[0011] Acquire the real-time active power of the unit based on the isolation result, and determine whether the real-time active power is within a preset unstable operation area to obtain a determination result;

[0012] Switching the swing protection constant corresponding to the real-time active power according to the judgment result to monitor the swing state of the unit to obtain a swing state monitoring result;

[0013] The corresponding alarm or tripping mechanism is triggered according to the vibration state monitoring result.

[0014] The hydro-generator set swing protection method based on power criterion and isolator in the embodiment of the present invention may also have the following additional technical features:

[0015] In one embodiment of the present invention, the active power transmission line of the unit is a 2-core cable.

[0016] In one embodiment of the present invention, before adding an isolator to the active power transmission line of the unit, the method further includes:

[0017] Set the range of active power collected in the unit's swing protection cabinet according to the range of active power collected in the unit's LCU cabinet.

[0018] In one embodiment of the present invention, the active power range collected in the LCU cabinet of the unit and the active power range collected in the swing protection cabinet of the unit are both 4-20mA range; the power range of the unstable operating area is -20MW to 190MW; the corresponding power range of the stable operating area is 190MW to 247.5MW.

[0019] In one embodiment of the present invention, the method further comprises:

[0020] Input the signal output by the unit to the input port of the isolator;

[0021] The output signal to be isolated is output from the output port of the isolator.

[0022] To achieve the above object, the present invention provides a hydro-generator set swing protection system based on power criterion and isolator, comprising:

[0023] Power acquisition module, used to obtain the real-time active power of the unit LCU;

[0024] A determination module, used for obtaining a determination result of whether the unit is located in an unstable operation area according to the real-time active power;

[0025] A set value switching module, used for switching the applicable swing protection set value according to the determination result;

[0026] A swing monitoring module is used to monitor the swing state of the unit according to the selected swing protection setting value to obtain the monitoring result;

[0027] The control module is used to trigger a corresponding alarm or trip mechanism according to the monitoring result.

[0028] The method and system for protecting the hydro-turbine generator set from swing based on power criteria and isolators of the embodiment of the present invention installs an isolator on the active power signal transmission line between the LCU A2 cabinet of the unit and the swing protection cabinet, and the isolator can achieve signal isolation and protection and reduce signal interference. In addition, the power criteria of the unit is added to the trip logic, and the applicable swing protection setting is automatically switched according to the real-time active power to avoid erroneous shutdown of the unit when it is running under unstable conditions.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0031] Figure 1is a flow chart of a method for protecting a hydro-generator set from sway based on power criteria and an isolator according to an embodiment of the present invention;

[0032] Figure 2 1 is a wiring diagram of a generator set active power being directly sent to a sway protection cabinet through a cable according to an embodiment of the present invention;

[0033] Figure 3 It is a wiring diagram of sending the active power of the unit to the swing protection cabinet through the isolator according to an embodiment of the present invention;

[0034] Figure 4 It is a structural schematic diagram of a hydro-generator set swing protection system based on power criteria and isolators according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] The following describes a method and system for protecting a hydro-generator set from swinging based on power criteria and isolators according to an embodiment of the present invention with reference to the accompanying drawings.

[0038] Figure 1 FIG. 1 is a flow chart of a method for protecting a hydro-generator set from oscillation based on power criteria and an isolator according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0039] S1, connects the unit LCU cabinet and the unit vibration protection cabinet through the unit active power transmission line;

[0040] S2, inputting the signal output by the unit into the isolator at a preset installation position, and transmitting the output isolated signal to obtain the isolation result between the input and output of the isolator and the power supply; wherein the preset installation position is the position on the active power transmission line of the unit;

[0041] S3, acquiring the real-time active power of the unit based on the isolation result, and determining whether the real-time active power is within a preset unstable operation area to obtain a determination result.

[0042] S4, switching the swing protection setting corresponding to the real-time active power according to the judgment result to monitor the swing state of the unit to obtain a swing state monitoring result;

[0043] S5, triggering a corresponding alarm or tripping mechanism according to the vibration status monitoring result.

[0044] Specifically, the present invention is combined with unit maintenance, laying cables from the unit monitoring system LCU A2 cabinet to the swing protection cabinet, activating the unit LCU analog output backup channel, connecting the unit active power signal to the swing protection device (the device hardware does not need to be changed), and coordinating with the manufacturer to upgrade the software configuration, adding the unit power judgment criteria to the trip logic to avoid erroneous shutdown of the unit when it is operating under unstable conditions. After the upgrade, two constants can be set in the swing protection device, one for the stable operating zone, and one for the unstable operating zone. The unstable operating zone is divided into a range of -20MW-190MW. See for specific wiring methods. Figure 2 .

[0045] It is understandable that since the analog output signal (unit active power) directly sent from the unit LCU A2 cabinet to the swing protection cabinet uses a 4-20mA current signal, it is easily interfered by the outside world during the transmission process, resulting in inconsistency between the active power collected in the unit LCU A2 cabinet and the active power sent to the unit swing protection cabinet.

[0046] Through experiments, it is found that the method of installing an isolator on the active power transmission line can effectively solve the problem of signal interference. The specific implementation steps are as follows:

[0047] Lay a 2-core cable from LCU A2 cabinet to the vibration protection cabinet; Figure 2 shown.

[0048] Set the range of active power collected in the unit's swing protection cabinet according to the range of active power collected in the unit's LCU A2 cabinet. Both collect 4-20mA, and the set ranges must be consistent;

[0049] Add an isolator to the active power transmission line. The isolator inputs current / voltage signals and transmits isolated current / voltage signals to output, thus realizing three-terminal isolation between input, output and power supply. It can effectively isolate the electrical interference between input and output, ensure the stability and accuracy of output signals, and respond quickly to changes in input signals and provide stable output signals in a short time. For specific access methods, see Figure 3 .in,

[0050] 1) Signal access: Connect the input signal to the input port of the isolator correctly and ensure that the ground wire is correctly connected.

[0051] 2) Signal output: The output signal to be isolated is obtained from the output port of the isolator to ensure that the device or system receiving the signal operates normally.

[0052] 3) Parameter adjustment: According to specific usage requirements, different isolation effects and signal processing methods can be achieved by adjusting the parameters on the isolator.

[0053] 4) Self-check function: The isolator has an automatic fault detection function. When a fault occurs, it will automatically sound an alarm and take appropriate measures.

[0054] Furthermore, the real-time active power of the unit is obtained from the monitoring system.

[0055] It is understandable that many power monitoring systems have real-time data display capabilities, which can directly view various power parameters including active power. For example, the monitoring system may provide a user interface through which the active power of each unit can be queried and displayed. If supported by the monitoring system, real-time data can be obtained through data communication interfaces (such as Modbus, IEC61850, etc.). This requires the monitoring system to have corresponding communication protocol support, and the equipment communicating with the monitoring system needs to support these protocols. In some cases, if real-time data is not available, real-time active power can be estimated by querying historical data. This usually involves analyzing historical trends and interpolating current data. In some systems with a high degree of automation, AGC can automatically adjust the active power output of the generator set to respond to changes in grid demand. The AGC system can provide real-time active power data. As part of the computer monitoring system of the hydropower station, the LCU is responsible for collecting and processing data during the operation of the hydropower station, including active power. The active power of the unit can be directly read through the LCU. The voltage and current in the power system are sampled and measured using a power analyzer to calculate the active power. This method is often used for precise measurement and can provide real-time data. Monitoring system reports and logs: The monitoring system may provide reports and logs to record historical data of active power. By analyzing this data, you can understand the trend of active power changes and estimate the real-time value based on it. If the monitoring system provides an API or data interface, you can obtain real-time active power data programmatically. This usually requires certain programming skills and understanding of the monitoring system interface.

[0056] Furthermore, it is determined whether the unit is located in an unstable operation area according to the real-time active power.

[0057] Specifically, based on real-time data, the power angle stability, voltage stability, and frequency stability of the unit are evaluated. If the fluctuation of real-time active power exceeds the threshold of the stable operation range, it may mean that the unit is in an unstable operation area. Once the unit is judged to be in an unstable operation area, corresponding control measures need to be taken, such as adjustment of the automatic generation control system (AGC), to maintain system stability. Real-time data is recorded and analyzed to predict and prevent possible unstable situations in the future. The evaluation results and treatment measures can also be reported to the grid dispatching department and relevant operators for further action.

[0058] Furthermore, the applicable swing protection setting is switched according to the determination result, and the swing state of the unit is monitored according to the selected swing protection setting; and the corresponding alarm or tripping mechanism is triggered according to the monitoring result.

[0059] Specifically, implement swing state monitoring, collect, process and store the vibration, swing and other signals of the unit in real time through sensors installed on the unit, and provide real-time monitoring, alarm protection output, fault diagnosis analysis and intelligent diagnosis report. Analyze the swing state monitoring results to evaluate the operating status and stability of the unit. If an abnormality is detected, the swing protection constant can be adjusted according to the actual situation to ensure the safe operation of the unit. According to the swing state monitoring results, if it is detected that the swing state of the unit exceeds the preset safety threshold, the alarm or trip mechanism is triggered to prevent equipment damage and ensure system safety.

[0060] According to the method for swing protection of a hydro-turbine generator set based on power criteria and isolators in an embodiment of the present invention, an isolator is added to the signal transmission line to effectively isolate electrical interference and ensure the stability and accuracy of the signal; by introducing the active power of the unit as a criterion, automatic switching of the swing protection setting between the stable operating area and the unstable operating area is achieved, effectively avoiding the situation of false triggering and tripping under unstable conditions, improving the reliability and safety of the system, and ensuring the stable operation of the hydropower station.

[0061] In order to implement the above embodiment, Figure 4 As shown, this embodiment also provides a hydro-generator set swing protection system based on power criterion and isolator, including:

[0062] The power acquisition module 100 is used to obtain the real-time active power of the LCU of the unit;

[0063] A determination module 200, configured to determine whether the unit is located in an unstable operation area according to the real-time active power;

[0064] A set value switching module 300, used for switching an applicable swing protection set value according to the determination result;

[0065] The swing monitoring module 400 is used to monitor the swing state of the unit according to the selected swing protection setting value to obtain a monitoring result;

[0066] The control module 500 is used to trigger a corresponding alarm or trip mechanism according to the monitoring result.

[0067] In one embodiment of the present invention, the active power transmission line of the unit is a 2-core cable.

[0068] In one embodiment of the present invention, before the power collection module 100, it also includes:

[0069] Line connection module, used to connect the unit LCU cabinet and the unit swing protection cabinet through the unit active power transmission line;

[0070] An isolator signal isolation module, used to input the signal output by the unit into the isolator at a preset installation position, and transmit the output isolated signal to obtain the isolation result between the input and output of the isolator and the power supply; wherein the preset installation position is the position on the active power transmission line of the unit;

[0071] The power range setting module is used to set the range of active power collected in the unit swing protection cabinet according to the active power range collected in the unit LCU cabinet.

[0072] In one embodiment of the present invention, the active power range collected in the LCU cabinet of the unit and the active power range collected in the swing protection cabinet of the unit are both 4-20mA range; the power range of the unstable operating area is -20MW to 190MW; the corresponding power range of the stable operating area is 190MW to 247.5MW.

[0073] In one embodiment of the present invention, the isolator signal isolation module is further used for:

[0074] Input the signal output by the unit to the input port of the isolator;

[0075] The output signal to be isolated is output from the output port of the isolator.

[0076] According to the hydro-turbine generator set swing protection system based on power criteria and isolators in the embodiment of the present invention, an isolator is installed on the active power signal transmission line between the unit LCU A2 cabinet and the swing protection cabinet, and the isolator can achieve signal isolation and protection and reduce signal interference. The unit power criterion is added to the trip logic, and the applicable swing protection constant is automatically switched according to the real-time active power to avoid erroneous shutdown of the unit when it is operating under unstable conditions. The present invention can effectively reduce signal interference, ensure the stability of signal transmission, and improve the reliability and accuracy of the swing protection system; through software configuration upgrades, two-stage constants can be set to make the swing protection system more flexible and intelligent.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0078] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A method for protecting a hydro-generator set from oscillation based on power criteria and an isolator, characterized in that: include: Connect the unit LCU cabinet and the unit vibration protection cabinet through the unit active power transmission line; Input the signal output by the unit into the isolator at a preset installation position, and transmit the output isolated signal to obtain the isolation result between the input and output of the isolator and the power supply; wherein the preset installation position is the position on the active power transmission line of the unit; Acquire the real-time active power of the unit based on the isolation result, and determine whether the real-time active power is within a preset unstable operation area to obtain a determination result; Switching the swing protection constant corresponding to the real-time active power according to the judgment result to monitor the swing state of the unit to obtain a swing state monitoring result; The corresponding alarm or tripping mechanism is triggered according to the vibration state monitoring result.

2. The method according to claim 1, characterized in that The active power transmission line of the unit is a 2-core cable.

3. The method according to claim 1, characterized in that Before adding an isolator to the active power transmission line of the unit, the method further includes: Set the range of active power collected in the unit's swing protection cabinet according to the range of active power collected in the unit's LCU cabinet.

4. The method according to claim 3, characterized in that The active power range collected in the LCU cabinet of the unit and the active power range collected in the swing protection cabinet of the unit are both 4-20mA; the power range of the unstable operation area is -20MW to 190MW; the corresponding power range of the stable operation area is 190MW to 247.5MW.

5. The method according to claim 4, characterized in that The method further comprises: Input the output signal of the unit to the input port of the isolator; The output signal to be isolated is output from the output port of the isolator.

6. A hydro-generator set sway protection system based on power criterion and isolator, characterized in that: include: Power acquisition module, used to obtain the real-time active power of the unit LCU; A determination module, used for obtaining a determination result of whether the unit is located in an unstable operation area according to the real-time active power; A set value switching module, used for switching the applicable swing protection set value according to the determination result; A swing monitoring module is used to monitor the swing state of the unit according to the selected swing protection setting value to obtain the monitoring result; The control module is used to trigger a corresponding alarm or trip mechanism according to the monitoring result.

7. The system according to claim 6, characterized in that The active power transmission line of the unit is a 2-core cable.

8. The system according to claim 6, characterized in that Before the power collection module, it also includes: Line connection module, used to connect the unit LCU cabinet and the unit swing protection cabinet through the unit active power transmission line; An isolator signal isolation module, used to input the signal output by the unit into the isolator at a preset installation position, and transmit the output isolated signal to obtain the isolation result between the input and output of the isolator and the power supply; wherein the preset installation position is the position on the active power transmission line of the unit; The power range setting module is used to set the range of active power collected in the unit swing protection cabinet according to the active power range collected in the unit LCU cabinet.

9. The system according to claim 8, characterized in that The active power range collected in the LCU cabinet of the unit and the active power range collected in the swing protection cabinet of the unit are both 4-20mA; the power range of the unstable operation area is -20MW to 190MW; the corresponding power range of the stable operation area is 190MW to 247.5MW.

10. The system according to claim 8, characterized in that Isolator signal isolation module, also used for: Input the output signal of the unit to the input port of the isolator; The output signal to be isolated is output from the output port of the isolator.

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