Introduction  With the putting into operation of Shenzhen Pumped Storage Power Station， the pressure of power supply in Shenzhen area will be reduced， the peak regulation range of thermal power and Western power will be reduced， the grid connected new energy generation will be promoted.

  Method  Due to the various operating modes of Shenzhen Pumped Storage Power Station， in order to verify the stability of the power system after Shenzhen Pumped Storage Power Station grid connected， the operation modes were simulated under four operation modes： maximum operating plan in summer， minimum operating plan in summer， maximum operating plan in winter， minimum operating plan in winter， and the stability and control measures of the power system after serious fault disturbance were studied.

  Result  According to the simulation results， two sets of setting value schemes are proposed for the out of step splitting device of Shenzhen Pumped Storage Power Station. When four units of the power station are connected to the grid through the 220 kV Yuan-Xu lines， the setting value of the voltage is set to 0.7 pu. In other modes， the setting value of the voltage is set to 0.5 pu， so as to ensure the units can be split timely and ensure the safety and stability of the system after power system failure under various conditions.

  Conclusion  The results of stability analysis provide a reference for operators， and some of the research results have been applied to the actual operation of field equipment.