Generator overspeed protection device

Abstract

The utility model provides an overspeed protection device for a generator. The overspeed protection device comprises a signal acquisition unit, a main processing unit, a signal output unit and a display unit, the signal acquisition unit is arranged on a bearing of the generator to be tachometer and is used for detecting the rotating speed of the generator to be tachometer, generating a rotating speed frequency signal and sending the rotating speed frequency signal to the main processing unit; the input end of the main processing unit is connected with the signal acquisition unit, and the output end is connected with the signal output unit and the display unit. The main processing unit receives and processes the rotating speed frequency signal, and if the alarm operation is determined to be executed according to the processed rotating speed frequency signal, an overspeed protection signal is sent to the signal output unit; the signal output unit sends the overspeed protection signal to a preset execution device so as to execute protection operation on the to-be-tachometer generator; the display unit displays the actual rotating speed value in real time. The rotating speed frequency signal is digitalized, overspeed diagnosis is automatically carried out, the reliability of the protection device is improved, and safe and stable operation of the generator to be subjected to speed measurement is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of generators, in particular to an overspeed protection device for generators. Background Art

[0002] The speed of the generator is determined by factors such as the amount of fuel injected and the air flow rate. When the load of the generator is suddenly reduced or out of control, the amount of fuel injected may increase, causing the generator speed to be too high, which may cause damage to the generator or cause other safety problems.

[0003] In order to avoid this situation, the generator is usually equipped with an overspeed protection device. Taking a diesel engine in a power station as an example, its overspeed protection device consists of a speed probe, a preamplifier and an overspeed box. The frequency signal measured by the overspeed probe coil is shaped by the preamplifier and then divided. The divided signal is compared with the frequency signal of the crystal oscillator (frequency reference value). If the measured frequency exceeds the reference frequency, it means that the diesel engine is overspeeding and an overspeed alarm signal is issued. This overspeed protection method is a primitive analog circuit control method, lacks the function of self-diagnosis, and cannot monitor the speed information when the overspeed protection signal is triggered in real time, which is not conducive to fault analysis. In addition, each divided signal is only compared with the frequency signal of a crystal oscillator (frequency reference value), and multiple threshold comparisons cannot be performed, so the reliability is low. Utility Model Content

[0004] In view of this, an embodiment of the utility model provides a generator overspeed protection device to solve the problems of being unable to automatically diagnose generator overspeed, being difficult to monitor speed information in real time, and being difficult to achieve multiple thresholds.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The first aspect of the utility model discloses a generator overspeed protection device, the device comprising: a signal acquisition unit, a main processing unit, a signal output unit and a display unit;

[0007] The signal acquisition unit is arranged on the bearing of the generator to be measured; the signal acquisition unit is connected to the input end of the main processing unit; the output end of the main processing unit is connected to the signal output unit; the signal output unit is connected to the preset execution device; the display unit is connected to the main processing unit;

[0008] The signal acquisition unit is used to detect the rotation speed of the generator to be measured, obtain a rotation speed frequency signal, and send the rotation speed frequency signal to the main processing unit;

[0009] The main processing unit is used to process the speed frequency signal to obtain an actual speed value, and to judge the actual speed value according to a plurality of preset thresholds, and to send an overspeed protection signal to the signal output unit when the judgment result indicates that an alarm operation is to be performed;

[0010] The signal output unit is used to send the overspeed protection signal to the preset execution device, so that the preset execution device performs a protection operation on the generator to be measured based on the overspeed protection signal;

[0011] The display unit is used to display the actual rotation speed value in real time.

[0012] Preferably, the signal acquisition unit comprises: a speed probe, a speed transmitter and an acquisition board;

[0013] The speed probe is arranged at a preset speed measuring position on the bearing of the generator to be measured, and the speed probe is connected to the speed transmitter via hard wiring;

[0014] The speed transmitter is connected to the main processing unit via the acquisition board;

[0015] The speed probe is used to detect the rotational running state of the generator to be tested;

[0016] The speed transmitter is used to convert the rotational running state detected by the speed probe into an electrical signal to obtain the speed frequency signal, and send the speed frequency signal to the main processing unit through the acquisition board.

[0017] Preferably, one end of the display unit is connected to a database; the display unit is specifically a display screen with a touch operation function.

[0018] Preferably, the main processing unit includes: a signal processing unit and a judgment unit;

[0019] The signal processing unit is connected to the signal acquisition unit;

[0020] One end of the signal processing unit is connected to the input end of the judgment unit, and the other end of the signal processing unit is connected to the display unit;

[0021] The output end of the judgment unit is connected to the signal output unit;

[0022] The signal processing unit is used to receive the speed frequency signal sent by the signal acquisition unit, and perform engineering quantity conversion on the speed frequency signal to obtain the actual speed value;

[0023] The judgment unit is used to receive the actual speed value sent by the signal processing unit; use multiple preset thresholds to compare with the actual speed value, if the comparison result indicates that the generator to be measured is in an overspeed state, and determine to perform an alarm operation based on the comparison result, then send the overspeed protection signal to the signal output unit.

[0024] Preferably, the judgment unit comprises: a first judgment module and a second judgment module;

[0025] An input end of the first judgment module and an input end of the second judgment module are respectively connected to the signal processing unit;

[0026] The output end of the first judgment module and the output end of the second judgment module are respectively connected to the signal output unit;

[0027] The first judgment module is used to receive the actual speed value sent by the signal processing unit; judge whether the speed generator to be measured is in an overspeed state according to a first threshold value, and if the speed generator to be measured is in an overspeed state, judge whether the speed generator to be measured is in a preset operation protection state; if the speed generator to be measured is not in the preset operation protection state, determine to perform an alarm operation and send the overspeed protection signal to the signal output unit;

[0028] The second determination module is used to receive the actual speed value sent by the signal processing unit;

[0029] It is determined whether the generator to be measured is in a target overspeed state according to a second threshold value. If the generator to be measured is in a target overspeed state, it is determined to perform an alarm operation and send the overspeed protection signal to the signal output unit; the second threshold value is greater than the first threshold value.

[0030] Preferably, the signal output unit is specifically a preset digital quantity output board.

[0031] Preferably, the signal output unit is connected to the preset execution device via a relay.

[0032] Preferably, the relay is connected to the preset execution device through a preset cable tray.

[0033] Preferably, the signal acquisition unit includes one or more speed probes, and a corresponding number of speed transmitters and acquisition boards.

[0034] Preferably, the first judgment module for judging whether the generator to be measured is in an overspeed state according to the first threshold value is specifically used for:

[0035] When receiving a plurality of the actual speed values, determining for each of the actual speed values ​​whether the current actual speed value exceeds a first threshold;

[0036] When the number of target actual speed values ​​among all actual speed values ​​exceeds a preset ratio, it is determined that the generator to be measured is in an overspeed state, wherein the target actual speed value is the actual speed value exceeding the first threshold value;

[0037] If the number of target actual speed values ​​among all actual speed values ​​does not exceed a preset ratio, it is determined that the generator to be measured is not in an overspeed state.

[0038] Based on the above-mentioned embodiment of the utility model, a generator overspeed protection device is provided, which includes a signal acquisition unit, a main processing unit, a signal output unit and a display unit; the signal acquisition unit is arranged on the bearing of the generator to be measured; the signal acquisition unit is connected to the input end of the main processing unit; the output end of the main processing unit is respectively connected to the signal output unit and the display unit; the signal acquisition unit is used to detect the speed of the generator to be measured, generate a speed frequency signal and send it to the main processing unit; the main processing unit is used to receive and process the speed frequency signal sent by the signal acquisition unit, and if it is determined to perform an alarm operation according to the processed speed frequency signal, an overspeed protection signal is sent to the signal output unit; the signal output unit is used to send the overspeed protection signal to a preset execution device to perform a protection operation on the generator to be measured; the display unit is used to display the actual speed value in real time. The speed frequency signal is digitized by the main processing unit, and overspeed diagnosis is automatically performed, so as to improve the reliability of the protection device and ensure the safe and stable operation of the generator to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0040] Figure 1 A first structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model;

[0041] Figure 2 A second structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model;

[0042] Figure 3 A third structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model;

[0043] Figure 4A fourth structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model;

[0044] Figure 5 This is an example diagram of a generator overspeed protection device provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0047] As can be seen from the background technology, the current overspeed protection device uses the frequency signal measured by the overspeed probe coil to be shaped by the preamplifier and then divided. The divided signal is compared with the frequency signal of the crystal oscillator (frequency reference value). If the measured frequency exceeds the reference frequency, it means that the diesel engine is overspeeding and an overspeed alarm signal is issued. This overspeed protection method is an original analog circuit control method, lacks the function of self-diagnosis, and cannot monitor the speed information when the overspeed protection signal is triggered in real time, which is not conducive to fault analysis; at the same time, the current overspeed protection device is only provided with a frequency signal (frequency reference value) of a crystal oscillator. If you want to set multiple frequency reference values, you need to add the frequency signal of the crystal oscillator in the circuit, which is difficult to increase and costly, and difficult to achieve.

[0048] Therefore, the embodiment of the utility model provides a generator overspeed protection device, which includes a signal acquisition unit, a main processing unit, a signal output unit and a display unit; the signal acquisition unit is arranged on the bearing of the generator to be measured, and is used to detect the speed of the generator to be measured, generate a speed frequency signal and send it to the main processing unit; the input end of the main processing unit is connected to the signal acquisition unit, and the output end of the main processing unit is connected to the signal output unit and the display unit respectively; the main processing unit receives and processes the speed frequency signal, and if it is determined to perform an alarm operation according to the processed speed frequency signal, an overspeed protection signal is sent to the signal output unit; the signal output unit sends the overspeed protection signal to a preset execution device to perform a protection operation on the generator to be measured; the display unit is used to display the actual speed value in real time. By digitizing the speed frequency signal, overspeed diagnosis is automatically performed, the reliability of the protection device is improved, and the safe and stable operation of the generator to be measured is guaranteed.

[0049] See also Figure 1 , shows a first structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model, the protection device includes: a signal acquisition unit 100, a main processing unit 200, a signal output unit 300 and a display unit 400.

[0050] Specifically, the signal acquisition unit 100 is arranged on the bearing of the generator 1 to be measured; the signal acquisition unit 100 is connected to the input end of the main processing unit 200 (e.g., a microprocessor (Microprocessor Unit, MPU)); the output end of the main processing unit 200 is connected to the signal output unit 300; the signal output unit 300 is connected to the preset execution device 2. Specifically, the signal output unit 300 is connected to the preset execution device 2 through one end of the relay, and the other end of the relay is connected to the preset execution device 2 through a preset cable tray. The display unit 400 is connected to the main processing unit 200, and specifically can be connected to the main processing unit 200 through a communication line.

[0051] It should be noted that the generator 1 to be tested is composed of an internal combustion engine (such as a diesel engine) and a generator. The signal acquisition unit 100 is specifically arranged at a preset speed measurement position of a bearing between the diesel engine body and the generator of the generator 1 to be tested.

[0052] It can be understood that the signal acquisition unit 100 is used to detect the rotation speed of the generator 1 to be measured, obtain a rotation speed frequency signal, and send the rotation speed frequency signal to the main processing unit 200 .

[0053] Specific, combined Figure 2 In the second structural block diagram of a generator overspeed protection device shown, the signal acquisition unit 100 includes a speed probe 101 , a speed transmitter 102 and an acquisition board 103 .

[0054] It should be noted that the speed probe 101 is set at a preset speed measurement position on the bearing of the generator 1 to be measured, and the speed probe 101 and the speed transmitter 102 are connected by hard wiring; the speed transmitter 102 is connected to the acquisition board 103, and the acquisition board 103 is connected to the main processing unit 200 by hard wiring.

[0055] In some specific embodiments, the acquisition board 103 is specifically an analog input (AI) acquisition board.

[0056] It can be understood that the speed probe 101 is used to detect the rotational running state of the preset speed measuring position on the bearing of the generator to be measured. The speed transmitter 102 is used to convert the rotational running state detected by the speed probe 101 (for example, convert the rotational running state detected by the speed probe 101 into an electrical signal of 4mA-20mA), obtain a speed frequency signal, and send the speed frequency signal to the main processing unit 200 through the acquisition board 103.

[0057] In a specific application, in order to improve the accuracy of speed measurement, a plurality of speed probes 101 and a corresponding number of speed transmitters 102 and acquisition boards 103 are arranged at a preset speed measurement position on the bearing of the generator 1 to be measured, for example Figure 2 As shown, three speed probes 101 and three speed transmitters 102 are arranged at preset speed measurement positions on the bearing of the generator 1 to be measured, and correspondingly, three acquisition boards 103 are arranged to connect the speed transmitters 102 .

[0058] Specifically, the main processing unit 200 is used to receive the speed frequency signal sent by the signal acquisition unit 100, process the speed frequency signal to obtain the actual speed value, and judge the actual speed value according to multiple preset thresholds. When the judgment result indicates to perform an alarm operation, an overspeed protection signal is sent to the signal output unit 300.

[0059] It should be noted that if the main processing unit 200 determines that the speed generator to be measured is not in an overspeed state after comparing the actual speed value with multiple preset thresholds, the alarm operation is not performed; or, if the main processing unit 200 determines that the speed generator to be measured is in an overspeed state after comparing the actual speed value with multiple preset thresholds, but the speed generator to be measured has already performed an overspeed protection action (that is, the generator to be measured is in a preset running protection state at this time) and the actual speed value of the speed generator to be measured does not reach the pre-defined direct alarm threshold, the alarm operation is not performed. For the specific comparison process, please refer to the following Figure 4 The content shown.

[0060] It should be noted that one end of the main processing unit 200 is connected to the database; the main processing unit 200 is also specifically used to store the actual speed value in the database. When the speed generator to be measured fails, the maintenance personnel can obtain the actual speed value of the speed generator to be measured that has been stored in the database, and perform fault analysis and troubleshooting on the generator based on the actual speed value stored historically.

[0061] Specifically, the display unit 400 is used to display the actual speed value in real time. That is, the main processing unit 200 processes the speed frequency signal and converts it into the actual speed value of the generator to be measured, and displays the actual speed value of the generator to be measured in real time on the display unit 400.

[0062] It can be understood that the display unit 400 is a video display unit (Visual Display Unit, VDU), specifically a display screen with a touch operation function.

[0063] Specifically, the signal output unit 300 is used to send the overspeed protection signal to the preset execution device 2, so that the preset execution device 2 performs a protection operation on the generator 1 to be measured based on the overspeed protection signal.

[0064] It is understandable that the signal output unit 300 is specifically a preset digital output board (Digital Output Board, DO). The signal output unit 300 is connected to the preset execution device 2 through a relay.

[0065] In a specific application, the main processing unit 200 and the signal output unit 300 can be arranged in a speed control cabinet, and the signal output unit 300 is connected to the terminals in the speed control cabinet, connected to the relay through the terminals, and then connected to the preset execution device 2 through a preset cable tray.

[0066] It can be understood that the electrical isolation of the protection circuit in the overspeed protection device is achieved based on the relay to prevent the overspeed protection signal from being interfered by the environment.

[0067] It can be understood that the execution device 2 performs a protection operation (for example, the protection operation is unit tripping and shutdown, protection shutdown) on the generator to be measured 1 based on the overspeed protection signal, which can effectively ensure the safe and stable operation of the generator to be measured.

[0068] In the embodiment of the utility model, multiple speed probes and speed transmitters are used to detect the real-time speed of the generator to be measured, thereby improving the accuracy of detection. The main processing unit is used to make an overspeed judgment based on the detected real-time speed value, and autonomously diagnose whether the generator to be measured is in an overspeed state and whether an overspeed protection action is required, thereby improving the reliability and applicability of the overspeed protection device. The overspeed protection signal is output to the preset execution device through the signal output unit, effectively protecting the safe and stable operation of the generator.

[0069] For further information, see Figure 3 , shows a third structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model, where the main processing unit 200 includes: a signal processing unit 201 and a judgment unit 202.

[0070] Specifically, the signal processing unit 201 is connected to the signal acquisition unit 100; one end of the signal processing unit 201 is connected to the input end of the judgment unit 202, and the other end of the signal processing unit 201 is connected to the display unit 400; the output end of the judgment unit 202 is connected to the signal output unit 300.

[0071] It should be noted that the signal processing unit 201 is used to receive the speed frequency signal sent by the signal acquisition unit 100, and perform engineering quantity conversion on the speed frequency signal to obtain the actual speed value. The judgment unit 202 is used to receive the actual speed value sent by the signal processing unit 201, and compare the actual speed value with a plurality of preset thresholds. If the comparison result indicates that the generator 1 to be measured is in an overspeed state, and it is determined to perform an alarm operation according to the comparison result, an overspeed protection signal is sent to the signal output unit 300.

[0072] In the specific application process, see Figure 4 , shows a fourth structural block diagram of a generator overspeed protection device provided by an embodiment of the utility model, where the judgment unit 202 includes: a first judgment module 2021 and a second judgment module 2022.

[0073] Specifically, the input end of the first judgment module 2021 and the input end of the second judgment module 2022 are respectively connected to the signal processing unit 201 ; the output end of the first judgment module 2021 and the output end of the second judgment module 2022 are respectively connected to the signal output unit 300 .

[0074] It should be noted that the first judgment module 2021 is used to receive the actual speed value sent by the signal processing unit 201; judge whether the speed generator to be measured is in an overspeed state according to the first threshold value; if the speed generator to be measured is in an overspeed state, judge whether the speed generator to be measured is in a preset operation protection state; if the speed generator to be measured is not in the preset operation protection state, determine to execute the alarm operation and send an overspeed protection signal to the signal output unit 300.

[0075] It should be further explained that, when the first determination module 2021 receives multiple actual rotation speed values ​​sent by the signal processing unit 201, it determines for each actual rotation speed value whether the current actual rotation speed value exceeds the first threshold.

[0076] When the number of target actual speed values ​​among all actual speed values ​​exceeds a preset ratio (for example, 2 / 3), it is determined that the speed generator to be measured is in an overspeed state, wherein the target actual speed value is an actual speed value exceeding a first threshold value; if the number of target actual speed values ​​among all actual speed values ​​does not exceed the preset ratio, it is determined that the speed generator to be measured is not in an overspeed state.

[0077] The second judgment module 2022 is used to receive the actual speed value sent by the signal processing unit 201; judge whether the generator to be measured is in the target overspeed state according to the second threshold value, and if the generator to be measured is in the target overspeed state, determine to execute the alarm operation and send an overspeed protection signal to the signal output unit 300; wherein the second threshold value is greater than the first threshold value.

[0078] It should be further explained that, when the second determination module 2022 receives multiple actual rotation speed values ​​sent by the signal processing unit 201, it determines for each actual rotation speed value whether the current actual rotation speed value exceeds the second threshold.

[0079] When the number of object actual speed values ​​among all actual speed values ​​exceeds a preset ratio (for example, 2 / 3), it is determined that the speed generator to be measured is in a target overspeed state, wherein the object actual speed value is an actual speed value exceeding a second threshold value; if the number of object actual speed values ​​among all actual speed values ​​does not exceed the preset ratio, it is determined that the speed generator to be measured is not in a target overspeed state.

[0080] It can be understood that when it is determined that the generator to be measured is in the target overspeed state, it is indicated that an alarm operation needs to be performed immediately.

[0081] It can be understood that judging whether the speed generator to be measured is in the preset operation protection state is specifically judging whether the operation protection signal for the speed generator to be measured sent in advance by the preset control protection cabinet is received. If the operation protection signal for the speed generator to be measured sent in advance by the preset control protection cabinet is received, it is determined that the speed generator to be measured is in the preset operation protection state; if the operation protection signal for the speed generator to be measured sent in advance by the preset control protection cabinet is not received, it is determined that the speed generator to be measured is not in the preset operation protection state. Among them, the operation protection signal is used to indicate that the speed generator to be measured allows overspeed in specific situations in the startup state, for example, the actual speed value of the speed generator to be measured can be greater than 1.12 times the standard speed value, but less than 1.15 times the standard speed value.

[0082] It can be understood that the actual speed value of the generator to be measured is judged in combination with the first judgment module 2021 and the second judgment module 2022, which improves the reliability of the generator overspeed protection device and avoids the problem of false triggering due to a single judgment circuit failure.

[0083] It should be noted that, in the judgment unit 202, multiple judgment modules can be set in a digital manner according to actual process application requirements, that is, not limited to the first judgment module 2021 and the second judgment module 2022, but multiple judgment modules can be set. Multiple judgment modules are used to realize multi-threshold judgment of safety-level parameters or non-safety-level parameters.

[0084] It is understandable that the embodiment of the utility model also supports a digital system based on FPGA\CPLD, etc., and the judgment unit 202 can be integrated into other instrumentation and control cabinets for implementation.

[0085] See also Figure 5 , the generator overspeed protection device disclosed in the embodiment of the utility model is explained with examples:

[0086] Three speed probes are arranged at the bearing speed measuring position between the diesel engine body and the generator, each speed probe is connected to a speed transmitter, and each speed transmitter is connected to an acquisition board.

[0087] Among them, each speed probe is used to detect the rotational operating state of a preset speed measurement position on the bearing, and a total of three rotational operating states are obtained, such as rotational operating state 1, rotational operating state 2 and rotational operating state 3; the speed probe sends rotational operating state 1, rotational operating state 2 and rotational operating state 3 to the speed transmitter, so that the speed transmitter converts rotational operating state 1, rotational operating state 2 and rotational operating state 3 into signals such as 4mA-20mA, and obtains speed frequency signal 1, speed frequency signal 2 and speed frequency signal 3.

[0088] The speed transmitter sends the speed frequency signal 1, speed frequency signal 2 and speed frequency signal 3 to the analog acquisition board in the speed control cabinet (such as Figure 5 The main processing unit receives the speed frequency signal 1, the speed frequency signal 2 and the speed frequency signal 3 through the analog acquisition board, and performs engineering quantity conversion on the speed frequency signal 1, the speed frequency signal 2 and the speed frequency signal 3, namely, digital-to-analog conversion (such as Figure 5 H_E) shown in , the actual speed value 1, the actual speed value 2 and the actual speed value 3 are obtained.

[0089] On the one hand, through the display unit (such as Figure 5 The VDU shown in FIG. 1 displays the actual speed value 1, the actual speed value 2 and the actual speed value 3 in real time.

[0090] On the other hand, in the main processing unit, the actual speed value 1, the actual speed value 2 and the actual speed value 3 are compared with the 112% speed threshold value and the 115% speed threshold value. The comparison process is as follows:

[0091] Determine whether the actual speed value 1, the actual speed value 2 and the actual speed value 3 exceed the first threshold value (such as 1.12 times the standard speed value) respectively; if any two of the actual speed value 1, the actual speed value 2 or the actual speed value 3 exceed the first threshold value, determine that the diesel generator is in an overspeed state, and determine whether the diesel generator is in a preset operation protection state; if the diesel generator is in the preset operation protection state, determine not to perform the alarm operation; if the diesel generator is in an overspeed state and the diesel generator is not in the preset operation protection state, determine to perform the alarm operation and output a 112% overspeed protection signal.

[0092] At the same time, it is determined whether the actual speed value 1, the actual speed value 2 and the actual speed value 3 exceed the second threshold value (such as 1.15 times the standard speed value); if any two of the actual speed value 1, the actual speed value 2 or the actual speed value 3 exceed the second threshold value, it is determined that the diesel generator is in the target overspeed state, the alarm operation is executed, and a 115% overspeed protection signal is output.

[0093] It should be noted that the 112% overspeed protection signal and / or the 115% overspeed protection signal are output via a digital output card (such as Figure 5 The DO (shown in the figure) is output to the terminal in the speed control cabinet, and then connected to the preset actuator through the relay and cable tray to achieve electrical isolation of the protection circuit in the generator overspeed protection device, avoiding interference of the 112% overspeed protection signal and / or 115% overspeed protection signal by the on-site environment. The preset actuator is used to protect the diesel generator, ensuring the safe and stable operation of the diesel generator.

[0094] In the embodiment of the utility model, the signal processing unit performs engineering quantity conversion, i.e., digital-to-analog conversion, on the speed frequency signal to obtain the actual speed value of the generator to be measured, thereby realizing the digitization of the generator overspeed protection. The judgment unit realizes the function of autonomous judgment, effectively identifies the generator overspeed fault, and further, uses a multi-threshold judgment method to improve the accuracy and reliability of the judgment.

[0095] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0096] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present utility model.

[0097] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A generator overspeed protection device, characterized in that: The device comprises: a signal acquisition unit, a main processing unit, a signal output unit and a display unit; The signal acquisition unit is arranged on the bearing of the generator to be measured; the signal acquisition unit is connected to the input end of the main processing unit; the output end of the main processing unit is connected to the signal output unit; the signal output unit is connected to the preset execution device; the display unit is connected to the main processing unit; The signal acquisition unit is used to detect the rotation speed of the generator to be measured, obtain a rotation speed frequency signal, and send the rotation speed frequency signal to the main processing unit; The main processing unit is used to process the speed frequency signal to obtain an actual speed value, and to judge the actual speed value according to a plurality of preset thresholds, and to send an overspeed protection signal to the signal output unit when the judgment result indicates that an alarm operation is to be performed; The signal output unit is used to send the overspeed protection signal to the preset execution device, so that the preset execution device performs a protection operation on the generator to be measured based on the overspeed protection signal; The display unit is used to display the actual rotation speed value in real time.

2. The device according to claim 1, characterized in that The signal acquisition unit includes: a speed probe, a speed transmitter and an acquisition board; The speed probe is arranged at a preset speed measuring position on the bearing of the generator to be measured, and the speed probe is connected to the speed transmitter via hard wiring; The speed transmitter is connected to the main processing unit via the acquisition board; The speed probe is used to detect the rotational running state of the generator to be tested; The speed transmitter is used to convert the rotational running state detected by the speed probe into an electrical signal to obtain the speed frequency signal, and send the speed frequency signal to the main processing unit through the acquisition board.

3. The device according to claim 1, characterized in that One end of the display unit is connected to a database; the display unit is specifically a display screen with a touch operation function.

4. The device according to claim 1, characterized in that The main processing unit includes: a signal processing unit and a judgment unit; The signal processing unit is connected to the signal acquisition unit; One end of the signal processing unit is connected to the input end of the judgment unit, and the other end of the signal processing unit is connected to the display unit; The output end of the judgment unit is connected to the signal output unit; The signal processing unit is used to receive the speed frequency signal sent by the signal acquisition unit, and perform engineering quantity conversion on the speed frequency signal to obtain the actual speed value; The judgment unit is used to receive the actual speed value sent by the signal processing unit; use multiple preset thresholds to compare with the actual speed value, if the comparison result indicates that the generator to be measured is in an overspeed state, and determine to perform an alarm operation based on the comparison result, then send the overspeed protection signal to the signal output unit.

5. The device according to claim 4, characterized in that The judgment unit includes: a first judgment module and a second judgment module; An input end of the first judgment module and an input end of the second judgment module are respectively connected to the signal processing unit; The output end of the first judgment module and the output end of the second judgment module are respectively connected to the signal output unit; The first judgment module is used to send the overspeed protection signal to the signal output unit when determining to perform an alarm operation according to the actual speed value and the first threshold value; The second judgment module is used to send the overspeed protection signal to the signal output unit when it is determined to perform an alarm operation according to the actual speed value and a second threshold value; the second threshold value is greater than the first threshold value.

6. The device according to claim 1, characterized in that The signal output unit is specifically a preset digital quantity output board.

7. The device according to claim 1, characterized in that The signal output unit is connected to the preset execution device through a relay.

8. The device according to claim 7, characterized in that The relay is specifically connected to the preset execution device via a preset cable tray.

9. The device according to claim 2, characterized in that The signal acquisition unit includes one or more rotation speed probes, and a corresponding number of rotation speed transmitters and acquisition boards.

Images