Design Of Asynchronous Condenser And Its Influence On System Stability

"Double high" system has the problems of low short-circuit ratio,low inertia and weak frequency modulation.In the face of faults,it lacks timely response ability,and the parameters such as frequency and voltage will flicker,which seriously threatens the safe operation of power system.The new power system requires that the synchronous machine or condenser can perform multiple functions at the same time to achieve high controllability.At present,it can be considered to install distributed condenser in each distributed new energy power station.Compared with large capacity synchronous condenser,distributed condenser has the advantages of flexible layout,high controllability and high economic benefits,and provides more reactive power and voltage support for new energy power generation system.Firstly,according to the operation characteristics of the distributed new energy power station,this paper determines the basic parameters of the asynchronous condenser,and then carries out the electromagnetic design of the distributed asynchronous condenser according to the basic parameter requirements,including the complete calculation process,including the main size,stator slot type,stator and rotor slot size and material selection,According to the existing performance parameter standards of the new generation synchronous condenser,its performance parameters are designed and optimized,the reasonable optimization process of asynchronous condenser is given,and the optimal parameters are determined.Secondly,the asynchronous condenser modulation coupling model is established by using the finite element analysis method.According to the operation requirements,the boundary conditions are set to analyze its no-load operation characteristics.Because the excitation mode and excitation control method determine the operation characteristics of asynchronous condenser,the differences of electrical parameters during synchronous operation of asynchronous condenser under different excitation schemes are analyzed,and five different excitation schemes are weighted and quantified according to the simplified analytic hierarchy process to determine the optimal excitation scheme;Under the optimal scheme,the operation characteristics of asynchronous condenser under different excitation amplitude and slip are analyzed.The correctness of the above model is verified by analyzing the operation characteristics of asynchronous condenser under no-load and load conditions.Finally,using the multi physical domain model of the verified asynchronous condenser,the transient operation characteristics of the distributed asynchronous condenser in multiple physical domains are analyzed.When the system has different conditions such as single-phase grounding short circuit in asymmetric short circuit,three-phase grounding short circuit in symmetric short circuit and sudden load change,the grounding resistance and load conditions under each different fault are analyzed,The asynchronous condenser can support the reactive power and voltage of the system.