Simulation and Characteristics of Combined Operation of Fixed and Variable Speed Pumped Storage Units Under Primary and Secondary Frequency Control
Compared to the fixed speed pumped storage unit(FSPSU),the variable speed pumped storage unit(VSPSU)has the unique advantages of quick adjustment and active support for the frequency-power of grid.This paper aims to study the simulation and characteristics of the combined operation of FSPSU and VSPSU under primary and sec-ondary frequency control.Firstly,the numerical simulation model for the combined operation of FSPSU and VSPSU un-der primary and secondary frequency control is established.Then,the coordinated simulation of primary and secondary frequency control is realized.Finally,the dynamic characteristics of the combined operation of FSPSU and VSPSU under primary and secondary frequency control are revealed.The results indicate that the amplitude of step disturbance of fre-quency becomes greater,the response time of 90%target value of primary frequency control and response time of target value of secondary frequency control for the output and active power of FSPSU and VSPSU become longer.The ratio of power regulation command of pumped storage unit becomes greater,the response time of target value of secondary fre-quency control for the output and active power becomes shorter.The response time of target value of secondary frequency control for the output and active power of VSPSU is more sensitive to the change of the ratio of power regulation com-mand.Under the same ratios of power regulation command for the FSPSU and VSPSU,the overall response time of tar-get value of secondary frequency control for the combined operation is shorter.
fixed speed pumped storage unitvariable speed pumped storage unitcombined operationprimary and secondary frequency controlnumerical simulationdynamic characteristics