Analysis And Research On Hydraulic Transition Process Of Heimifeng Pumped Storage Power Station

Since the reform and opening up,China's economy has developed rapidly,and the demand for electricity in various industries has increased.China's current power generation mode is mainly based on thermal power,but in recent years,with the increasing environmental protection efforts,the clean energy of hydropower has been highly respected.Among them,the pumped-storage power station plays an important role in the power grid with its unique advantages.The “peak-shaving and valley-filling” of the power grid ensures the stable operation of the power grid.Pumped storage power stations have more operating conditions and more frequent conversions.In this process,the transition process is likely to directly threaten the safety of the pumped storage power station.Therefore,it is necessary to study the transition process of pumped storage power stations.This paper takes the Heifeng Peak Pumped Storage Power Station as the research object.The full characteristic curve of the pump turbine and the processing method of the full characteristic curve,namely the suter conversion and its improvement method are introduced.Based on the simulink module and S-Function programming method in MATLAB toolbox,based on the characteristic line method,the computer simulation model of hydraulic transition process of the unit was established.The simulation calculation was carried out,and the turbine load rejection condition and pump pumping were broken.The electrical conditions were analyzed and studied.The results are as follows:Under the condition of turbine,the simulation of the closing rules of the two water guiding mechanisms is carried out,and the two closing laws are closed in two stages.The first closing law is 0.1-95-10-0.5,and the second closing law is 0.1-28-13-0.65.When the water guiding mechanism is normally closed,the parameters of the hydraulic transition process of the two closed laws are within the allowable values of the given adjustment guarantee calculation.Since the shutdown time of the shutdown rule I is short,it is recommended to use the shutdown rule I in actual operation.For the closing law I,when the water guiding mechanism is closed abnormally,that is,a unit that normally shuts down one unit and refuses to move,the simulation calculation is also performed,and the parameters are also within the given adjustment guarantee calculation allowable values.The calculation result is that the maximum speed is 427.26r/min,the maximum water hammer pressure of the volute inlet is 453.92 m,and the minimum water hammer pressure of the draft tube inlet is 37.82 m.Under the condition of the pump,the straight-line closing law is adopted,and the closing time is 9.41 s.The simulation results show that when the water guiding mechanism is closed normally,the pump turbine is still in the pump working condition during the closing process,and no unit reversal occurs,and it will not transition to the turbine working condition.When the water guiding mechanism is shut down abnormally,that is,one unit normally shuts down one unit and refuses to move.The calculation results show that although the rejecting force group transitions to the turbine working condition and reaches the runaway,the speed value is 432.81r/min.Not exceeding 50% of the rated speed,the maximum and minimum water hammer pressures are also within the allowable values for the given adjustment guarantee calculation.The calculation results show that the parameters of the hydraulic turbine working condition and the pump working condition are in compliance with the requirements of the regulation and calculation specifications.