ABB TPS02 Turbine Protection Slave Module

ABB TPS02 Turbine Protection Slave Module

Overview

Product Definition and Function: ABB TPS02 Turbine Protection Slave Module is an important slave module in the turbine protection system. It is mainly used to receive and process various signals related to the operating status of the turbine, such as vibration, temperature, pressure, speed and other signals, and work with the master protection module or control system to achieve comprehensive protection for the turbine. Its functions include signal acquisition, processing, monitoring and timely triggering of protective actions under abnormal conditions to ensure that the turbine operates within safe operating parameters.

Working Principle

Signal Acquisition Process

Interface with sensors: The TPS02 module has several input interfaces for connecting various types of sensors. These sensors can be accelerometers for monitoring turbine shaft vibration, thermocouples or RTDs for monitoring temperature, pressure sensors for monitoring pressure, and magnetic sensors for monitoring rotational speed. When a vibration sensor is connected, for example, the sensor converts the information on the amplitude and frequency of the vibrations of the turbine into electrical signals (e.g. voltage or current signals) and transmits them to the analogue input interface of the module.

Signal conditioning and preliminary processing: The received sensor signals first pass through a signal conditioning circuit. For analogue signals, this includes filtering operations to remove high-frequency noise and interference components from the signal, which may come from surrounding electrical equipment or the electromagnetic environment. At the same time, the weak signal is amplified to bring the signal to a level suitable for subsequent processing. For example, for weak millivolt-level signals output from temperature sensors, they are amplified to a suitable volt-level range by signal conditioning circuits to improve the quality and accuracy of the signals. For digital signals (e.g. pulse signals output from speed sensors), buffering and level matching processes are performed to ensure signal stability and compatibility.

Signal Processing and Analysis Process

Analogue to digital conversion (A/D conversion): The conditioned analogue signal is fed into the analogue to digital conversion circuit. The module has an A/D converter with a certain resolution, e.g. 12 - 16 bit resolution. This means that it is possible to quantise the analogue signal into numerous discrete digital values. By sampling and quantising the analogue signal, it is converted into digital form for subsequent digital processing. The sampling frequency is set according to the characteristics of the signal and the monitoring needs. For fast changing signals (e.g. vibration signals), a higher sampling frequency will be used to accurately capture the changes in the signal.

Signal feature extraction and analysis: The converted digital signal will be further processed inside the module. Through built-in algorithms and logic circuits, the signals are feature extracted, for example, by calculating parameters such as amplitude, frequency and phase of vibration signals, or trend analysis of temperature signals. The results of these analyses are used to determine whether the turbine is operating in a normal state. At the same time, the module compares the processed signals with preset protection thresholds. These protection thresholds are set according to the design parameters and safe operation requirements of the turbine, for example, a maximum allowable vibration amplitude is set, and when the amplitude of the vibration signals exceeds this threshold, it may indicate that an abnormal condition has occurred in the turbine.

Protection action triggering and co-operation process

Protection logic judgement: based on the results of signal processing and comparison, the protection logic circuit inside the module will make a judgement. If any one or more of the monitored parameters are detected to be out of the safe range, a protective action will be triggered. The trigger logic of the protection action may be based on a single parameter exceeding the limit, or multiple parameters exceeding the limit at the same time or meeting certain combination conditions. For example, if the turbine speed exceeds 110% of the rated speed and the vibration amplitude exceeds the set threshold, a hazardous condition is recognised and a protective action is triggered.

Coordination with master module or control system: The TPS02 acts as a slave module and transmits the processed signals and protection status information to the master protection module or to the host control system. This can be done via a communication interface (e.g. Profibus - DP, Modbus and other industrial communication protocols). After receiving this information, the master protection module or control system will synthesise the information from all slave modules and make the final protection decision. For example, the master module may decide whether to issue a local alarm, a partial equipment shutdown or an emergency shutdown of the entire turbine based on the status of the individual slave modules.

Performance Features

High-precision Signal Processing Capability: During signal acquisition and processing, the turbine's operating parameters can be accurately acquired and analysed due to its high-precision A/D conversion (accuracy up to ±0.1% - ±0.5% full-scale accuracy) and advanced signal analysis algorithms. This is important for accurately determining the operating status of the turbine and detecting potential faults in a timely manner, such as accurately detecting small vibration frequency changes and temperature increases.

Multi-Channel Signal Processing: Typically has multiple input channels to process many different types of sensor signals simultaneously. The number of channels may vary from 8 - 16, depending on the module type. This multi-channel design allows for comprehensive monitoring of several key parameters of the turbine, such as simultaneous monitoring of shaft vibration at different locations, temperature, pressure, and speed in different parts of the turbine, providing a wealth of data to support the overall protection of the turbine.

Compatibility and Communication Function: It supports a variety of industrial communication protocols (such as Profibus - DP, Modbus, etc.), and can conveniently communicate with the main protection module, the upper control system and other related devices. This makes it well integrated into the existing turbine protection system to achieve data sharing and cooperative work. Meanwhile, the communication interface can support different communication rates and can be flexibly configured according to system requirements.

Reliability and anti-interference ability: It adopts high-quality electronic components and advanced circuit design, which has good anti-interference ability and can operate stably in harsh industrial environments. For example, through signal filtering and shielding measures, it can effectively resist electromagnetic interference (EMI) and radio frequency interference (RFI), ensuring accurate signal acquisition and transmission. At the same time, the module has certain fault diagnosis and fault tolerance ability, and can take corresponding measures (such as alarming, switching to the backup channel, etc.) when partial failure occurs, so as to reduce the impact on the protection function of the turbine.

Technical Parameters

Input parameters

Number and range of analogue input channels: Generally there are 8 - 16 analogue input channels, capable of receiving a wide range of analogue signal types. For example, the voltage signal range can include - 10V - + 10V, 0 - 10V, etc., and the current signal range can include 4 - 20mA, 0 - 20mA, etc., in order to adapt to the output signals of different sensors.

Digital Input Types and Level Standards: Supports a variety of digital signal types, such as TTL (Transistor Transistor Logic) levels, CMOS (Complementary Metal Oxide Semiconductor) levels, TTL levels generally range from 2V - 5V at high levels and 0V - 0.8V at low levels; CMOS level ranges vary depending on the specific device.

Input Signal Resolution (Analogue Inputs): Analogue input channels can have a resolution of 12 - 16 bits, with higher resolutions enabling more accurate acquisition of analogue signals.

Conversion Parameters (A/D Conversion)

A/D Conversion Accuracy: Conversion accuracy of ±0.1% - ±0.5% full-scale accuracy ensures highly accurate signal conversion.

Sampling Frequency Range: The sampling frequency range is wide, generally ranging from several thousand times per second to several hundred thousand times per second, which can be set according to the actual application requirements. For example, for high-frequency vibration monitoring, a higher sampling frequency may be used; while for low-frequency temperature monitoring, a lower sampling frequency may be used.

Communication Parameters

Supported communication protocols: It supports various industrial communication protocols such as Profibus - DP, Modbus, etc., which is convenient for communication with the control system and other devices.

Communication rate: The communication rate varies according to the communication protocol and connection method used. For example, in Profibus - DP communication, the communication rate can reach 12Mbps; in using Modbus protocol to communicate through serial port, the communication rate can be between 9600bps - 115200bps.