| In recent years,with the increasing demand for electric power,the proportion of power system electronic power and new energy installed capacity has increased year by year,and system fluctuations have become more frequent and intense.At the same time,people have higher and higher requirements for power supply reliability,and static voltage is stable.Sexual issues are becoming more prominent.Therefore,it is necessary to study the influence of new changes in power system on the static voltage stability of the system from different levels of the load-network-source.This paper first proposes a static voltage stability analysis method for power systems based on improved ZIP load model.Combining the simulated plant growth algorithm with the fuzzy C-means clustering,according to the proposed load clustering evaluation system,the time periods with similar load changes are combined.An improved ZIP load model is proposed,and the node load is divided by load decomposition method.Loads with industrial load characteristics,loads with residential load characteristics and loads with commercial load characteristics;based on the improved ZIP model,study the effects of different types of load random growth on system static voltage stability.Secondly,this paper proposes a static voltage stability analysis method that takes into account the effects of harmonics.Combining Latin hypercube sampling,improved dichotomy and decoupling method,considering the random variation of linear load in the system,the uncertainty of nonlinear load and the randomness of distributed power output,a new harmonic power flow calculation is proposed.The method can be regarded as the characteristic of system disturbance.The voltage sensitivity index and voltage distortion sensitivity index are proposed.The influence of harmonics on the static voltage stability of the system is quantitatively analyzed.The static voltage based on weak nodes,safety domain and sensitive nodes is proposed.The stability analysis method divides all nodes of the system to find the weak nodes in the current system harmonic content level,and traces the sensitive nodes when the harmonic permeability increases,so as to better evaluate the static voltage stability of the system.Finally,the sequential solution method for the power flow of the electric-gas coupled integrated energy system is given.Considering the energy coupling relationship between the electrical system(EPS)and the natural gas system(NGS),consider the new energy unit.Uncertainty of output and random fluctuation of electric load and air load,solve EGCIES trend;propose a minimum load shedding strategy,combine the three-stage load shedding strategy with improved dichotomy in EPS,and apply it to NGS system To quickly and accurately solve the minimum load shedding of the system under extreme conditions;in the case of power supply point and gas source point failure,taking into account the electro-pneumatic coupling characteristics,through the stability analysis method proposed in this paper,from EPS stability,NGS stability and EPS and NGS coupling ability multi-angle quantitative analysis of the stability of the electric-gas coupled integrated energy system,and solve the inflection point of EPS and NGS energy complementary. |
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