Research On PHIL Digital-Analog Hybrid Simulation Platfrom Interface Model Under Network Environment

With the development of renewable energy power generation technology,Power Hardware-in-the-loop(PHIL)digital-analog hybrid simulation platform based on RTDS is the effective means to study large-scale new energy integration technology of grid.But RTDS is expensive and the grid size built in a RTDS equipment is small.Combining different RTDS in different regions based on PHIL technology under network environment,a large-scale power grid of digital-analog hybrid simulation platform can be established,which can be used to study the large scale renewable energy imtegration technology in large power grid.But under the network environment,there are some problems,such as network latency and packet loss,will seriously impact the stability and precision of the PHIL digital-analog hybrid simulation platform based on RTDS.Thus,it is theoretical and practical important to study the network latency and packet loss problems in PHIL digital-analog hybrid simulation platform under the network environment.In this dissertation,after analyzing the structures and transfer functions of voltage type interface model,different performances of them are demonstrated by simulation.Then the corresponding current type interface model is put forward.The simulation results show that the proposed current type interface models has better stability and precision than the voltage type interface models.As for the network latency problem in PHIL digital-analog hybrid simulation system,principle of phase compensation in frequency domain is analysised in Ideal Tansformer Model(ITM).In addition,the Current-Adaptive Simplified Damping Impedance Method(C-ASDIM)is proposed and its stability and precision are analysised.The simulation results show that the proposed C-ASDIM can effectively solve the time delay problem in PHIL digital-analog hybrid simulation system under network environment.As for the problem of packet loss in PHIL digital-analog hybrid simulation system under network environment,the performances of packet loss compensation are analyzed with the methods based on the Least Squares-Support Vector Machines(LS-SVM)and data storage compensation.Simulation results show that the packet loss compensation method based on data storage has the advantages of fast speed and high accuracy.Finally,with current tracking type power converter model and the proposed C-ASDIM,the digital-analog hybrid simulation model under network environment is established in Matlab/Simulink.Then simulation analysis is carried out on the conditions of network delay,packet loss and load mutation.The simulation results suggest that the proposed interface models in this thesis is valid.