Static Voltage Stability Assessment Of Offshore Platform Group Grids

With the continuous development of social economy,people's living standards continue to improve,electricity and energy needs and requirements are also increasing,followed by resource shortages,environmental pollution and other issues has become increasingly severe.In order to alleviate and solve these problems,"new energy revolution","marine engineering" and other projects came into being.Ocean platform power grid as a "marine engineering" offshore operating platform for the production and life of electricity support,its power quality and voltage stability of the offshore operating platform for the normal operation of production and living.Therefore,it is necessary to analyze the voltage stability of offshore platform power grid.Considering the common characteristics of the offshore platform grid and the multi-regional interconnected power grid and the influence of the special environment of the ocean on the offshore platform power grid,this paper puts forward the L Indicator Collaborative Computing Method of voltage stability based on the improved REI equivalent method considering the influence of the boundary correlation on the basis of the multi-regional interconnected power grid.The main research contents are as follows:(1)Based on the computational idea of "decomposition-coordination",based on the power balance equation of interconnected power grid,the influence of regional power relations on regional boundary is clarified,and the improved REI equivalent model based on local data of regional power grid is deduced,and makes it possible to reflect the dynamic characteristics of the interconnected power grid to a certain extent.(2)Using the method of linear regression analysis of intercept change,the effective sample point set is selected according to the local data of the regional power grid.After the transformation and time weighted regression.the equivalent parameters of the improved REI equivalent method in the case of single boundary node is obtained.Then,according to the empirical value of the voltage and reactive power between the boundary nodes,the equivalent parameters of the improved REI equivalent method in the case of multi-boundary nodes are obtained.(3)The improved REI equivalent parameter is substituted into the basic node information of the regional power grid,and a new node admittance matrix is obtained.And the change of the load participation factor F matrix used in the calculation of L index is deduced.The transformed F matrix is taken back to the L-metric calculation formula,and the L-index cooperative calculation method for the stability evaluation of the interconnection grid voltage is obtained.(4)Select the standard IEEE14 node system,IEEE118 node system and an actual power grid model,write the tidal current example,simulate the correctness of the above method,and apply this method to the actual ocean platform power network in the Bohai area,and evaluate the voltage stability of the actual offshore platform grid preliminary.(5)according to the particularity of offshore platform power grid,considering the influence of cable capacitance effect on the offshore platform of power grid,through the re value of submarine cable part parameters,fixed voltage stability assessment of offshore platform power system.Based on the analysis of the voltage stability of several multi-regional interconnected power grids and the actual offshore platform in the Bohai area,this paper presents a method of calculating the voltage stabilization L index of the modified REI equivalent method considering the boundary correlation,and simulation verifies the correct effectiveness of the proposed method.And the method requires only the regional grid operating parameters,reducing the interconnection between the communication and computing load.