Transient Stability Analysis And Emergency Control Of Power System Considering OPC Function

At present,China's thermal power plant installed capacity is still more than 60%,it is of great significance to maintain the safe and stable operation of the power system.Over-speed protection controller(OPC)is an important device for suppressing the speed of the unit and keeping the safety of the equipment in the steam turbine.In this paper,the purpose is to study the effect of OPC on the transient stability of power system,and to optimize the parameters in order to better play the role of OPC and improve the safe and stable operation level of power system.Firstly,this paper analyzes the main functions and operating characteristics of the OPC protection device o f the steam turbine,and establishes the electromechanical transient simulation model of synchronous generator set with OPC protection function,tests and analyzes the four basic functions,which is Automatic Stop Tripping,Close Interceptor Valves,Load Drop Anticipation and Over-speed Protection Control,of OPC in the simulation.The simulation results show that CIV and 103% over-speed protection have a direct effect on the transient stability of the power system,and the correct action can improve the transient stability of the systemThen,combined with the time domain simulation method,analyzes the influence of OPC protection device on the transient stability of power system by mechanism and simulation.Using the New England 10 machine 39 node system,through a large number of simulation examples,simulate the effect of OPC on the system power angle,speed,mechanical power,limit removal time of each node under the three-phase short circuit.The simulation results show that,in the OPC correlation function,CIV action with the maximum frequency,and it impacts on transient stability of the widest,103% over-speed protection action less frequency,but can significantly improve transient stability limit removal time.Finally,combined with the optimal fast-off control law and time domain simulation to optimize the parameters of OPC,so that OPC in a particular short-circuit fault control under the optimal effect.Combined with the wide area stability control system,the strategy of incorporating OPC into the wide area protection is given.Through the wide area stability control,it implements the online correction of CIV's continuous shutdown time,avoids the problem of multiple units OPC "with the same open",and can better coordinate OPC and fast values,cutting machine,load and other emergency control strategy action to improve the system transient stability.