Research On Black-start Of Power System

With the expansion of the scale of the power grid,the access of renewable power sources marked by photovoltaics and wind power,and natural disasters,personnel errors or failure of automatic control equipment have increased the hidden dangers of grid disconnection and even crashes.Although the probability of large-scale and long-time blackouts is not high,it cannot be completely avoided or eliminated.Once it occurs,huge losses to power companies and the national economy will not only be brought out,but also the serious impact on people's production and life.The black start recovery scheme of the power grid is an important part of the grid emergency planning.The black start sources selection and system recovery process are the top priorities of the emergency plan.Therefore,how to use renewable energy to generate electricity as the black start power source to enhance the reliability of the black start scheme,how to optimize the sub-area to accelerate the recovery process of the entire power grid,together with how to determine the optimal grid-connected time after the sub-area recovery,comprise a great significance to effectively and stably restore the output of the unit in the shortest time after a large-scale collapse.This paper has carried out in-depth analysis and research on related issues.The main research contents and results are as follows:(1)A black start power supply planning method for wind,light,storage,and combustion of multiple renewable energy sources is proposed.This paper first analyzes the feasibility of the renewable energy power generation system as the black start power supply of the power grid,and establishes the power generation model of wind,light,storage and combustion.Then based on this,a variety of renewable energy power generation systems are proposed as the capacity optimization configuration model of the black start power supply.Finally,using the meteorological data and load demand of our country,the particle swarm algorithm is used to solve the model,and the multi-renewable energy system is built in PSCAD as the simulation model of black start power,and its black start capability and optimization are verified.The validity of the results.(2)The optimal partitioning strategy for the recovery sub-region of the "unit division + load division" system is proposed.The unit division model considering the recovery time balance is established,and the load segmentation and system recovery sub-area are determined by the knapsack algorithm with connected graph constraints.The feasibility and effectiveness of the restoration sub-area partitioning method are verified by an IEEE 39-node system.(3)An electromechanical transient grid-connected simulation method for recovering sub-regions is proposed.Firstly,the mathematical model of the whole power grid and its dynamic components is established.Then,the simulation program for simulating the grid-connected process of the generator is developed,and the optimal grid-connecting time of each sub-area is determined.Based on the research results,the power grid is developed.The auxiliary decision-making software for the black start plan provides technical support for the grid operators to develop a black start plan.