A system and method for analyzing precision loss of a steam turbine measurement data transmission process

Abstract

The application discloses a kind of steam turbine measurement data transmission process precision loss analysis system and method, belong to precision loss analysis technical field.System includes vibration measurement module, current receiving module, serial communication module and data processing module;Steam turbine sensor is converted into original voltage signal by the measurement data collected, vibration measurement module connects steam turbine sensor, for receiving original voltage signal storage, original voltage signal is converted into current signal;Current receiving module and serial communication module are all connected vibration measurement module, current receiving module receives current signal, and serial communication module receives original voltage signal;Data processing module connects current receiving module and serial communication module, and the precision loss is calculated according to received current signal and original voltage signal.This application does not need to stop, does not need to disconnect wire in whole process, can be completed in the normal operating state of unit whole-range precision loss evaluation.

Description

Technical Field

[0001] This invention belongs to the field of precision loss analysis technology, specifically relating to a precision loss analysis system and method for the data transmission process of steam turbine measurement. Background Technology

[0002] The Turbine Supervisory Instrumentation (TSI) system is an important monitoring and protection method to ensure the safe operation of steam turbines. It is mainly used to continuously measure mechanical parameters of steam turbines such as speed, vibration, differential expansion, axial displacement, cylinder expansion, and rotor eccentricity, and send the measurement results to the control and protection system. On the one hand, it allows operators to monitor and analyze the operation of rotating machinery, and on the other hand, it executes alarm and protection functions when parameters exceed the limits, thus safeguarding the safe operation of the steam turbine unit.

[0003] A distributed control system (DCS) is an automated control system based on microprocessors, designed with decentralized control functions and centralized display and operation. Its core architecture includes a process control level and a process monitoring level, and the hardware consists of field control stations, operator stations, and engineer stations. It achieves hazard dispersion and centralized management through a hierarchical structure.

[0004] Steam turbines are among the most critical pieces of equipment in power plants, and their monitoring and control are essential for ensuring the safe, stable, and efficient operation of the unit. Most of the turbine data is collected locally by sensors. Signals such as displacement, temperature, and speed are converted from digital to analog signals and transmitted via shielded cables to the corresponding modules in the TSI (Transmission System) for signal reception and processing. Currently, power plants integrate the processed analog data from the TSI system into the DCS (Distributed Control System) for unified monitoring of the entire power plant, providing operators with a global perspective on equipment status and decision support.

[0005] Among all measured data, turbine shaft vibration and displacement are crucial, serving as core indicators for assessing the unit's health status and directly reflecting the stability and safety of shaft operation. The vibration amplitude and displacement magnitude are typically at the micrometer level, demanding extremely high measurement accuracy and real-time performance. Micrometer-level calculations mean that any accuracy issues can lead to data processing anomalies and damage to the turbine. Therefore, developing an effective method to address the accuracy loss during the transmission of analog quantities from the TSI system to the DCS system is essential.

[0006] Throughout the process, the turbine shaft vibration data is first converted from micrometers to voltage signals, then the voltage signals are converted to current signals, and finally the current signals are received. At all three points, there is an issue of accuracy loss in the analog signal. Since sensors are field devices and not within the scope of this control system discussion, this application primarily addresses the latter two methods for measuring accuracy loss.

[0007] Currently, methods for measuring accuracy loss mainly rely on manual segmented verification and empirical estimation: a high-precision ammeter is connected to the output side of the TSI terminal to measure the output value, and a standard resistor is connected in parallel to the input side of the DCS terminal to sample the voltage. The current value is then calculated and the difference between the two is considered as the transmission link error. This method requires shutdown, disconnection, and multiple reconnections, which is not only cumbersome and poses high safety risks, but also cannot reflect real-time error drift under dynamic load changes. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a system and method for analyzing the accuracy loss of steam turbine measurement data transmission. The entire process does not require machine shutdown or disconnection, and the full-range accuracy loss assessment can be completed under normal unit operation.

[0009] This invention provides the following technical solution:

[0010] In a first aspect, a precision loss analysis system for the data transmission process of steam turbine measurement data is provided, comprising: a system for calculating the precision loss of measurement data from steam turbine sensors during the transmission process from the steam turbine safety monitoring system to the distributed control system;

[0011] The accuracy loss analysis system includes a vibration measurement module, a current receiving module, a serial communication module, and a data processing module.

[0012] The turbine sensor converts the collected measurement data into a raw voltage signal. The vibration measurement module is connected to the turbine sensor and is used to receive and store the raw voltage signal and convert the raw voltage signal into a current signal.

[0013] Both the current receiving module and the serial communication module are connected to the vibration measurement module. The current receiving module receives the current signal, and the serial communication module receives the original voltage signal.

[0014] The data processing module is connected to the current receiving module and the serial communication module, and calculates the accuracy loss based on the received current signal and the original voltage signal.

[0015] The original voltage signal is transmitted between the vibration measurement module and the serial communication module via the MODBUS RTU communication protocol.

[0016] As an optional technical solution of the present invention, the timing of the current receiving module receiving the current signal and the timing of the serial communication module receiving the original voltage signal are aligned using an NTP time server.

[0017] As an optional technical solution of the present invention, the vibration measurement module includes a storage unit, a conversion unit and a communication unit;

[0018] The input terminal of the storage unit is connected to a steam turbine sensor to receive and store the raw voltage signal;

[0019] The input terminal of the conversion unit is connected to the output terminal of the storage unit, and is used to convert the original voltage signal into a current signal;

[0020] The input terminal of the communication unit is connected to the output terminal of the storage unit, and is used to transmit the original voltage signal to the serial communication module.

[0021] As an optional technical solution of the present invention, the communication unit transmits the original voltage signal to the serial communication module through the MODBUS RTU communication protocol.

[0022] As an optional technical solution of the present invention, the output end of the conversion unit is connected to the current receiving module through a shielded cable;

[0023] The output of the communication unit is connected to the serial communication module via a shielded cable.

[0024] In a second aspect, a method for accuracy loss analysis of a turbine measurement data transmission process based on the first aspect is provided, comprising: acquiring the current signal sent by the current receiving module and the original voltage signal sent by the serial communication module;

[0025] The accuracy loss is calculated based on the current signal and the original voltage signal.

[0026] As an optional technical solution of the present invention, the step of calculating the accuracy loss based on the current signal and the original voltage signal includes:

[0027] Based on predetermined conversion parameters, the current signal is converted into a corresponding voltage signal, as follows:

[0028] V1'=(V1-a)*b;

[0029] Where V1 represents the current signal, V1' represents the voltage signal corresponding to the current signal, a represents a predetermined deviation term, and b represents a predetermined coefficient;

[0030] The calculation accuracy loss is expressed as:

[0031] TLoss = |V2-V1'| / V2*100%;

[0032] Where TLoss represents the accuracy loss and V2 represents the original voltage signal.

[0033] As an optional technical solution of the present invention, the process of determining the conversion parameters includes:

[0034] Map the current values ​​within the pre-acquired target current range to the target voltage range to obtain the voltage values ​​corresponding to the current values ​​within the target current range;

[0035] Plot a linear curve of the current value and its corresponding voltage value within the target current range, and determine the conversion parameters, which include the deviation term and coefficients.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] This invention provides a precision loss analysis system for turbine measurement data transmission. Without changing the hardware interface structure of the analog transmission link between the existing TSI and DCS, without changing the original wiring method, and without increasing the on-site shutdown window, the system uses a serial communication module to receive the original voltage signal to calculate the precision loss. The original voltage signal is transmitted between the vibration measurement module and the serial communication module through the MODBUS RTU communication protocol, so there is no precision loss. The entire process does not require shutdown or disconnection, and the full-range precision loss assessment can be completed under normal unit operation. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the accuracy loss analysis system in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the first accuracy loss in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the second accuracy loss in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of SCM module communication in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of signal processing within the DCS system in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides a system for analyzing the accuracy loss of steam turbine measurement data transmission, used to calculate the accuracy loss of measurement data from steam turbine sensors during transmission from the steam turbine safety monitoring system to the distributed control system. For example... Figure 1 As shown, it includes: a vibration measurement module (corresponding to...) Figure 1 VMP module), current receiving module (corresponding) Figure 1 AI module), serial communication module (corresponding) Figure 1 SCM module and data processing module (corresponding) Figure 1 Medium DPU).

[0046] The turbine sensor converts the collected measurement data into raw voltage signals. The vibration measurement module is connected to the turbine sensor and is used to receive and store the raw voltage signals and convert them into current signals. In this embodiment, the VMP module is used to monitor displacement signals such as shaft vibration and bearing vibration of the turbine. When a signal is generated, the sensor installed on the turbine converts the displacement signal into a voltage signal. Typically, the displacement is set to -10000µm to +10000µm, corresponding to a voltage of -10V to +10V, that is, 1µm corresponds to 1mV voltage. The voltage signal is transmitted to the VMP module.

[0047] Furthermore, the vibration measurement module includes a storage unit (corresponding to...) Figure 1 (memory chip), conversion unit (corresponding) Figure 1 AO module) and communication unit (corresponding to Figure 1 (Communication port). The input terminal of the storage unit is connected to the turbine sensor to receive and store the raw voltage signal; the input terminal of the conversion unit is connected to the output terminal of the storage unit to convert the raw voltage signal into a current signal; the input terminal of the communication unit is connected to the output terminal of the storage unit to transmit the raw voltage signal to the serial communication module.

[0048] Both the current receiving module and the serial communication module are connected to the vibration measurement module. The current receiving module receives the current signal, and the serial communication module receives the raw voltage signal. The timing of the current receiving module receiving the current signal and the timing of the serial communication module receiving the raw voltage signal are aligned using an NTP time server to ensure timestamp alignment and consistent sampling periods, thereby eliminating the interference of timing deviations on accuracy comparison.

[0049] The data processing module connects the current receiving module and the serial communication module, and calculates the accuracy loss based on the received current signal and the original voltage signal.

[0050] Furthermore, the output of the conversion unit is connected to the current receiving module via a shielded cable. The output of the communication unit is connected to the serial communication module via a shielded cable.

[0051] like Figure 2 As shown, the voltage signal is stored in the memory of the VMP module. The AO module of the VMP module converts the -10V to +10V voltage signal into a 4 to 20mA current signal for output. During the conversion process, there will be a loss of data accuracy. This loss is mainly determined by the accuracy of the VI conversion circuit in the VMP module, and is referred to as the first accuracy loss.

[0052] like Figure 3 As shown, the current signal is sent to the AI ​​module of the DCS system via a shielded cable. When the AI ​​module acquires the current signal, there is also a loss in data accuracy. This loss is mainly related to the selection of the AI ​​module's ADC chip, sampling resistor, and reference chip, and is denoted as the second loss. Therefore, the total accuracy loss TLoss of the analog signal transmitted from the TSI system to the DCS system is the sum of the first and second accuracy losses.

[0053] like Figure 4 As shown, the raw voltage signal is transmitted between the vibration measurement module and the serial communication module via the MODBUS RTU communication protocol, without any accuracy loss. The communication unit transmits the raw voltage signal to the serial communication module via the MODBUS RTU communication protocol, and the voltage signal stored in the storage unit can be directly sent to the DCS system via the serial communication link.

[0054] Example 2

[0055] This embodiment provides a system for analyzing the accuracy loss in the data transmission process of a steam turbine measurement system, including:

[0056] Step 1: Obtain the current signal sent by the current receiving module and the original voltage signal sent by the serial communication module.

[0057] Step 2: Calculate the accuracy loss based on the current signal and the original voltage signal. Specifically:

[0058] like Figure 5 As shown, based on predetermined conversion parameters, the current signal is converted into a corresponding voltage signal, expressed as follows:

[0059] V1'=(V1-a)*b;

[0060] Where V1 represents the current signal, V1' represents the voltage signal corresponding to the current signal, a represents a predetermined deviation term, and b represents a predetermined coefficient.

[0061] In this embodiment, the 4-20mA current value V1 is converted into a -10V to +10V voltage value V1', where a=12 and b=1.25.

[0062] The calculation accuracy loss is expressed as:

[0063] TLoss = |V2-V1'| / V2*100%;

[0064] Where TLoss represents the accuracy loss and V2 represents the original voltage signal.

[0065] The process of determining the conversion parameters includes:

[0066] Map the current values ​​within the pre-acquired target current range to the target voltage range to obtain the voltage values ​​corresponding to the current values ​​within the target current range;

[0067] Plot a linear curve of the current value and its corresponding voltage value within the target current range, and determine the conversion parameters, which include the deviation term and coefficients.

[0068] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0070] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0071] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A system for analyzing the accuracy loss in the data transmission process of a steam turbine measurement system, characterized in that, This is used to calculate the accuracy loss of measurement data from turbine sensors during the transmission process from the turbine safety monitoring system to the distributed control system; The accuracy loss analysis system includes a vibration measurement module, a current receiving module, a serial communication module, and a data processing module. The turbine sensor converts the collected measurement data into a raw voltage signal. The vibration measurement module is connected to the turbine sensor and is used to receive and store the raw voltage signal and convert the raw voltage signal into a current signal. Both the current receiving module and the serial communication module are connected to the vibration measurement module. The current receiving module receives the current signal, and the serial communication module receives the original voltage signal. The data processing module is connected to the current receiving module and the serial communication module, and calculates the accuracy loss based on the received current signal and the original voltage signal. The original voltage signal is transmitted between the vibration measurement module and the serial communication module via the MODBUS RTU communication protocol.

2. The accuracy loss analysis system for turbine measurement data transmission process according to claim 1, characterized in that, The timing of the current receiving module receiving the current signal is aligned with the timing of the serial communication module receiving the original voltage signal using an NTP time server.

3. The accuracy loss analysis system for turbine measurement data transmission process according to claim 1, characterized in that, The vibration measurement module includes a storage unit, a conversion unit, and a communication unit; The input terminal of the storage unit is connected to a steam turbine sensor to receive and store the raw voltage signal; The input terminal of the conversion unit is connected to the output terminal of the storage unit, and is used to convert the original voltage signal into a current signal; The input terminal of the communication unit is connected to the output terminal of the storage unit, and is used to transmit the original voltage signal to the serial communication module.

4. The accuracy loss analysis system for turbine measurement data transmission process according to claim 3, characterized in that, The communication unit transmits the original voltage signal to the serial communication module via the MODBUS RTU communication protocol.

5. The accuracy loss analysis system for turbine measurement data transmission process according to claim 3, characterized in that, The output of the conversion unit is connected to the current receiving module via a shielded cable. The output of the communication unit is connected to the serial communication module via a shielded cable.

6. A method for accuracy loss analysis of an accuracy loss analysis system based on the turbine measurement data transmission process according to any one of claims 1-5, characterized in that, include: Acquire the current signal sent by the current receiving module and the original voltage signal sent by the serial communication module; The accuracy loss is calculated based on the current signal and the original voltage signal.

7. The method for analyzing the accuracy loss in the turbine measurement data transmission process according to claim 6, characterized in that, The accuracy loss calculated based on the current signal and the original voltage signal includes: Based on predetermined conversion parameters, the current signal is converted into a corresponding voltage signal, as follows: V1'=(V1-a)*b; Where V1 represents the current signal, V1' represents the voltage signal corresponding to the current signal, a represents a predetermined deviation term, and b represents a predetermined coefficient; The calculation accuracy loss is expressed as: TLoss = |V2-V1'| / V2*100%; Where TLoss represents the accuracy loss and V2 represents the original voltage signal.

8. The method for analyzing the accuracy loss in the turbine measurement data transmission process according to claim 7, characterized in that, The process of determining the conversion parameters includes: Map the current values ​​within the pre-acquired target current range to the target voltage range to obtain the voltage values ​​corresponding to the current values ​​within the target current range; Plot a linear curve of the current value and its corresponding voltage value within the target current range, and determine the conversion parameters, which include the deviation term and coefficients.

Images