Research On The Mechanism Of Energy Storage In Power System Small-signal Stability Control

With the development of economy and society,integration of large-scale renewables and marketization reform of electric utilities,power systems will face many difficulties and challenges.Among them,power system stability problem is always the very important aspect.Considering that the applications of energy storage could cover power generation,transmission,distribution and demand,and energy storage has the flexible active and reactive power control capability,this thesis deeply conduct the mechanism research of energy storage in power system stability control,especially in power system small signal stability control.This thesis briefly introduces the types and operation principle of converter based energy storage device at first.Then,the control scheme of the converter(to achieve the active and reactive power decoupled control)is detailed.And the dynamic model of the converter based energy storage device is obtained at last.Based on the mathematical model of the single machine infinite bus system with power system stabilizer,this thesis establishes the extended Heffron-Philips model(single machine infinite bus system with energy storage),and then analyses the function route of energy storage's effects on electromagnetic torque and studies the damping characteristics of reactive power control(Q-control)and active power control(P-control)by energy storage.In the single machine infinite bus system,this thesis firstly conducts the comparison study of Q-control,P-control and conventional damping method using PSS,and then analyses the adaptability(considering different excitation gain,system parameters,operation condition and fault conditions).Finally,the comprehensive assessment of application prospect of energy storage in power system small signal stability control is performed.