Automated process control system (automated process control system) of the turbine of station No. 3 of the Brest CHP

Purpose of the system:

АThe automated process control system is designed for automated control of turbine operation and auxiliary equipment in order to achieve optimal technological parameters, increase the reliability of turbine operation in various modes and the safety of service personnel through the use of modern microprocessor control systems and computer equipment.

Description of the system:

The auxiliary equipment to be automated includes:

• network electric pumps;
• deaerator;
• heat supply pumps;
• condensate pumps of the chemically treated water heater;
• sewage pumping pumps;
• fire extinguishing pumps;
• hydraulic lock of thermal network protection;
• circulating pumps of circulating water supply;
• fan cooling towers

System structure:

• • The lower level includes technological equipment, actuators and an information and measuring complex of sensors.
  • The middle level (the level of technological control subsystems), consisting of a programmable logic controller SIMATIC S7-400H (SIEMENS) and ET200M (SIEMENS) stations. The basis of the stability of the system is redundancy at the level of the programmable logic controller and communication with the I/O subsystem and the database server, which allows the programmable controller to autonomously perform tasks of safe process management. Information exchange between distributed I/O stations and control controllers is implemented over the PROFIBUS DP network. The distributed system allows not only to significantly reduce the number of cable lines, but also to remove individual technological installations and nodes from the process without stopping the main technological process. The main task of the level is the collection and processing of current data on the state of the technological process, the implementation of automatic control and control algorithms. Turbo generator protection algorithms, automatic control, safety locks, AVR algorithms are implemented at the PLC program level.
  • Operational management level – the level of remote monitoring and control of actuators, setting the operating modes of control subsystems with the functions of technological signaling (audio and visual) at operator stations, maintaining archives on operational data, both on the condition of equipment and on the measured parameters of the technological process on the server, based on the WinCC (SIEMENS) SCADA system. Communication between the components of the operational management level and the middle level is implemented over a redundant Industrial Ethernet network. The functionality of our SCADA system allows you to quickly parameterize the protection of the turbo generator from any workstation, depending on the access level, adjust the regulators, control the AVR algorithms. The consequence of triggering one protection may be the cascade triggering of a group of protections, as a reaction to a sharp change in technology parameters. The system uniquely determines which protection worked first and led to an emergency stop. A special message “Emergency stop from protection N” is generated, the reason for the emergency stop is visually displayed on the screen form of the protections. Any action to change the protection parameters is recorded and logged by the message registration system. The consequence of triggering one protection may be the cascade triggering of a group of protections, as a reaction to a sharp change in technology parameters. The system uniquely determines which protection worked first and led to an emergency stop. A special message “Emergency stop from protection N” is generated, the reason for the emergency stop is visually displayed on the screen form of the protections. Algorithms for automatic reserve input (AVR) allow you to switch to backup equipment without shock and painlessly for the technical process, while there may be several conditions for triggering the AVR, as well as configurations of working and backup actuators. The solutions we use in the field of automatic control of process parameters have rich tools for configuration and adjustment with differentiation by access level

The solutions we use in the field of automatic control of process parameters have rich tools for configuration and adjustment with differentiation by access level.

• The upper level is a display of information about the progress of the technological process at the workstations of the management staff via a Web interface with the exception of control functions and changes in the operating modes of control subsystems. The upper level is implemented for all automation systems implemented by our company as part of the comprehensive reconstruction of the Brest CHP. Using standard industrial network solutions, the automated process control system can be connected to other equivalent systems or incorporated into higher-level enterprise management systems (ERP, MES). According to the applied method of implementation, the automated process control system has no restrictions on the development of the structure and composition of the system at all levels.