The nuclear safety video display unit (SVDU) in the nuclear safety level DCS implements functions such as displaying and warning of reactor safety related parameters and sending safety control instructions, which belongs to safety level 1 equipment. As a high-cost complex safety level display device, due to its high functional complexity, high security and reliability requirements, and special usage scenarios, its design, research, and function verification have always encountered problems such as low intelligence and low digitization, resulting in slow development process, complicated product function verification, and inconvenient use and training, etc. After the SVDU is put into practical use, continuous analysis of its stability, reliability, and safety, and its health status monitoring and maintenance are also difficult technical problems.
Based on the five-dimensional digital twin model as a design benchmark, a digital twin-based design method for SVDU is proposed. Taking the SVDU in a nuclear safety level DCS (NASPIC) as the object, the digital twin technology is adopted to model the physical objects such as display unit, human-machine interface unit, storage unit and communication network unit, and the high-speed industrial Ethernet network is used to map and interconnect the data between the components, so as to realize the physical fusion, model fusion and data fusion of the real SVDU and the virtual SVDU. With the help of data feedback from safety level DCS, the data, symbol display and control process of SVDU can be visualized and analyzed in virtual environment, and the real-time control function verification, fault early warning and auxiliary decision-making can be carried out, which improves the visibility, accessibility, operability and predictability of real SVDU display and control process. The real-time data, historical data, fault self-diagnosis data, and expert experience of real SVDU and virtual SVDU are incorporated into the twin data pool to reproduce the variable-speed replay of the historical operation process of SVDU and realize the post-accident condition analysis with multiple spatiotemporal dimensions; the record and analysis of self-fault diagnosis data provides the possibility of stability analysis services such as clock, power supply, human-machine input, and storage equipment, etc.
Digital twin-based SVDU technology can ensure rapid development and iteration of products under the requirements of complex functions and high safety and reliability, and truly reproduce the display and control effects of SVDU, while meeting users’ multiple application scenarios and data service requirements.