Webfield ® DEH system

DEH intelligent module

DEH speed measurement and overspeed protection module:

By combining three speed measurement and overspeed protection modules with the base to form a hardware three out of two structure, and connecting with the speed measurement terminal board, the speed measurement and overspeed protection I/O unit of the DEH system is formed, achieving high-precision speed measurement while achieving hardware overspeed protection of less than 10ms. The module adopts intelligent design, which can independently perform speed measurement and overspeed protection without a main control unit, and all adopt a fully digital circuit design. After each hardware module independently judges, it is finally judged by the "two out of three" logic, ensuring the fast and reliable operation of the system; The module has built-in isolated network operation function, and the card has built-in acceleration and other key signal calculation functions. It is directly connected to the servo module through a high-speed bus to achieve the goal of quickly responding to isolated network operation control requirements. Equipped with live plug and unplug function, it can directly plug and unplug cards when the system is live, without affecting the normal operation of the system.

DEH electro-hydraulic servo module:

Adopting intelligent design, equipped with zero amplitude self-tuning technology, and utilizing intelligent signal technology to adapt to common electro-hydraulic converters in the market; The hardware I/O design with multiple inputs and outputs can receive multiple channels, multiple standard signals, and LVDT position feedback signals. LVDT supports disconnection diagnosis and has a built-in dedicated control loop with a minimum control cycle of 10ms; Equipped with an external manual interface to enable various auxiliary signals such as manual addition/subtraction of the controller; Built in isolated network operation function, connected to the speed measurement module through high-speed bus, and enabled with built-in isolated network operation algorithm to achieve fast and stable control function; Equipped with online maintenance function, convenient valve maintenance can be achieved through built-in management function in multi valve mode.

● Comprehensive DEH control function

As a subsystem of the WebField ECS series of central control systems, the DEH and DCS systems operate on the same network with complete data sharing, achieving an integrated design of DCS-DEH. They are equipped with intelligent interface cards, making it easy to interconnect with other heterogeneous DCS, PLC, intelligent instruments, and expand their functions. The human-machine interface provides comprehensive and practical functions such as flowcharts, alarms, real-time trends, historical trends, operation records, adjustment screens, fault diagnosis, and accident recall.

The DEH control scheme realizes speed control, power control, and steam pressure control, and can achieve machine furnace coordination and electric heating coordination. It also uses multiple cascade feedback regulation loops to ensure dynamic response and static characteristics. Mature algorithms have been used to implement valve management functions, ensuring safe and disturbance free switching between single valve and sequential valve control modes. The rigorous algorithm ensures easy online maintenance even in case of faults. Equipped with simulation function, offline simulation is used to train operators, and online simulation can be used to verify the correctness of control logic and check whether the control system is normal.