Research On The Application Of Fault Diagnosis And Fault Tolerant Control In Thermal System Of Power Plant

In modern power plant, the safety of the control systems has received more and more attention. The paper is committed to the research on the application of fault diagnosis and fault tolerant control in the modern power plant .The new schemes of fault diagnosis both for boiler water level control system and unit coordinated control system are presented; moreover, based on the LQG strategy, a scheme of fault tolerant control for unit coordinated control system is also proposed. The main contributions are as follows:1.The usual instrument faults existing in boiler water level control system are intensively investigated and described mathematically.2.A scheme of instrument fault detection in boiler water level control system is presented based on the parity space method .The processes of the fault detection of instruments of steam flow, feed-water flow, and water level are introduced, the effectiveness of the fault detection scheme presented is shown by the simulation results.3.The multi-variable, coupling turbine-boiler plant is intensively investigated and with the reference of the routine control method, LQG control strategy is used in the turbine-boiler plant successfully; moreover the usual fault existing in the unit coordinated control system is researched. The model set for the sensor fault, actuator fault and normal control system is builded. Based on adaptive filter technology, a scheme of fault diagnosis and fault tolerant control in the unit coordinated control system is presented.4.With the result of the fault diagnosis of the unit coordinated control system, a new scheme of active fault tolerant control is proposed. The tolerant control is realized through reconfiguring the control law. The effectiveness of the fault diagnosis and fault tolerant control scheme presented is show by the simulation result.