Research And Application Of Coordinated Control Strategy Optimization For330MW Unit

Research on coordinated control system, which has a highpriority in automationof power plant,has never been stopped since its initial appearance. This essay focuseson the coordinated control system for330MW unit.The first chapter introduces the task, development and state of the art of thisresearch in both domestic and international environment.The second chapterintroduces the fundamental theories of coordinated control system, including theoverview of the system, operation mode, the principle and index of primaryfrequence adjustment, the concept and structure of automatic generation control(AGC) as well as the concept and principle ofrunback. These background knowledgehelp to show the importance of coordination control system on power plant’s tableand reliabe operation. In the third chapter, optimizations on control strategies of thecoordinated control system are introduced by analysing the coordination control logicof a330MW thermal power unit and comparing with other units’control situation.This kind of optimaztions includes adding correctiontoAGC signal and adjustment tofrequency (primary frequence adjustment) in the load command control; addingpressure feedback loop to master control of turbine; introducing multiple feedforwardsignal, such as fuel quantity, derivative of turbine pressure error, derivative of turbinepressure set point, pre-feeding function of coal and derivative of the drum pressureerror. More examples are the cancellation of logic of superheater andreheater’sdesuperheating water valvein RB control loop and the addition of theturbine following PID controller in RB mode and the PID controller of furnacepressure large deviation.Finally, the optimized control strategy is applied to the scene. Load variationtest,primary frequenceadjustment test, AGC test and RB test are conducted separately.The resulting curve shows that this control strategy has good control qualityintheperformance test. No matter when the unit is in operation state or in a accident,primary parameters are all within the required range from the regulations.This controlstrategy can be used inthe control system of similar units because of itscharacteristics of generalization and demonstration.It’s also a valuable reference tothe design of other coordinated control strategy and the debugging of units.