HVDC Operation Plan For Large Energy Base With Wind-Thermal Power

Large-scale wind farms are typically geographically separated from load centers in China.Therefore large-scale wind power in Northwest area need continuously transmitted over a long distance to the eastern area where load is concentrated by HVDC,for the reason that HVDC has the advantage of long distance transmission and large capability.During ‘The thirteenth Five-Year' period,State Grid Corporation of China plans several ±800kV and ±1100kV HVDC projects,in order to meet the demand of power transmission from west region to east area.The flexible adjustment of HVDC can improve the ability of inter-regional power grid to accommodate new energy.But the adjustment of HVDC active power will lead to frequency movement of HVDC reactive power control equipment,which will shorten their service life.In order to maximize renewable energy accommodation and make full use of the regulation ability of HVDC,a strategy of HVDC power operation is proposed to adapt to the multi-time scale coordinated scheduling of the isolated HVDC transmission system.Taking day-ahead HVDC transmission scheduling for example,a new mathematical model of HVDC tie-line operation optimization taking most economical operation of inter-regional grid and the minimization of the wind power curtailment as optimization objective is developed with consideration given to the additional regulation cost of HVDC reactive power control equipment and various constraints on AC and DC system to finally get HVDC base power for each plan period.Case studies are constructed to validate the effectiveness of the model and method.