Method for switching safety power sources of power plant on basis of DCS (distributed control system)

Abstract

The invention relates to a method for switching safety power sources of a power plant on the basis of a DCS (distributed control system). The method includes steps of (1), inputting states of bus protection devices configured on safety sections in the power plants, protection outlets of overcurrent protection devices configured on circuit breakers, position junctions of the circuit breakers and diesel-driven generators into the DCS of the power plant and performing logical configuration; (2), enabling the DCS to judge switching values after logical configuration according to the importance of load, controlling the circuit breakers and the diesel-driven generators, and transmitting load starting instructions in batches to switch the safety power sources so that the important load on the safety power sources can be automatically recovered and run. The method has the advantages that 'voltage loss' and 'permanent faults' can be judged, so that the safety power sources can be reliably switched, existing devices of the power plant are sufficiently utilized to achieve the purpose of switching the safety power sources, and the cost is saved.

Description

technical field [0001] The invention belongs to the technical field of unit automatic power generation control, in particular to a DCS-based power plant security power switching method. Background technique [0002] In the case of power failure of the whole plant, in order to ensure the normal shutdown of the generator set and avoid damage to the equipment, it is necessary to ensure that some important loads of the power plant can be continuously powered, such as: air preheater motor, fire detection cooling fan, AC sealed oil pump, Lubricating oil pump and other loads to ensure that the unit can be shut down safely. The current practice is to connect these important loads to the "safety section". The load is switched through the standby automatic switching device to prevent power loss in the "safety section". 1. The current method mostly adopts the introduction of standby automatic switching device to realize the switching of security power supply, but the standby automatic...

AI Technical Summary

Problems solved by technology

1. The current method mostly adopts the introduction of standby automatic switchover device to realize the switching of the security power supply, but the standby automatic switchover device can only control the switch on the power side according to the voltage and current criteria, and cannot realize the self-starting of important loads after the bus voltage is restored. At the same time, this method requires the purchase of self-switching protection devices, which increases costs; 2. DCS is the abbreviation of Distributed Control System (Distributed Control System), which is composed of process control level and process monitoring level. The multi-level computer system can realize decentralized control, centralized operation, hierarchical management, flexible configuration and convenient configuration

However, purely relying on DCS logic to achieve switching also has its obvious disadvantages. Since the voltage and current collected in the DCS system are all 4-20mA quantities provided by the transmitter, the reliability, accuracy and fault transient characteristics of the sampling are high. It is not as good as traditional protection and automatic devices, so it is not as accurate as traditional protection and automatic devices in terms of logical judgments such as "permanent failure" and "low voltage action" based on voltage, current and switching values.

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