Research On The Configuration Method Of Energy Storage System When Apply Storage-based Wind Farm As Black-start Power Source

The hydropower plant has characteristics of less auxiliary power and fast self-starting speed,and thus it becomes the best choice for black-start power source.But there are few hydropower plants in Inner Mongolia and Northwest China,and the grid recovery will only rely on the main grid after blackout with a long recovery time.In these areas,the wind power is the main power generation form,and by configuring large-capacity battery energy storage system for wind farms,they can be used as a black-start power source,which plays an important role in improving the recovery speed of power grid after blackout.As the core part of storage-based wind farm,energy storage system can make up the difference between the output power of wind farm and the demand power during the black-start process,which ensures the black-start to proceed smoothly.Therefore,research on the configuration method of energy storage system,and research on the coordinated control strategy of storage-based wind farm to optimize the configuration results,which can help to reduce the cost of energy storage system and improve the economic feasibility of applying the storage-based wind farm as the black-start power source.Taking Hulun Buir power grid as the research object,the configuration method of energy storage system and the power coordinated control strategy of storage-based wind farm are studied in this paper,when applying the storage-based wind farm as the blackstart power source.(1)The simulation model of double-fed wind turbine and battery energy storage system is established.The mathematical model of double-fed induction generator in noload and grid-connected condition is established,and then the mathematical model is discretized by implicit trapezoid method,based on which the dual operation simulation model is established.Then through the analysis of the operating principle of the battery energy storage system,the equivalent model of the battery is established,and then the simulation model of battery energy storage system is built.(2)A configuration method of energy storage system when apply storage-based wind farm as black-start power source is proposed.The deficiencies of existing configuration methods and the affecting factors of battery energy storage system configuration are analyzed.Then,the connection mode of energy storage system and the battery type are determined.And then the minimum rated capacity and the limit power of battery module,the rated capacity of inverter in the power conversion system are respectively configured,and the double-target optimization model of rated capacity of battery module is established using the linear weighted sum method.Finally,the simulation results show that the configuration cost of energy storage system can be reduced effectively by the proposed configuration method,and the impact on the configuration results from the wind farm output power is explored.(3)The power coordinated control strategy of storage-based wind farm,during the black-start process of thermal power unit,is researched.The strategy contains the local control strategy,active power and negative power coordination controller,transition mechanism of coordination controller between various black-start stages,calculation module of output power limit of wind farm.And with application of this strategy,energy storage system’s state of charge can be maintained in the middle value to reduce energy fluctuation,and its reactive power can be adjusted to zero.The simulation results show that the cost of configuring energy storage system can be further reduced with the coordinated control strategy,and the charge-discharge capacity and power regulation margin of energy storage system is increased.By research in this paper,the energy storage system is configured when apply storagebased wind farm as black-start power source,and the coordinated control strategy is researched in order to optimize the configuration results,and the economic feasibility of applying wind farm as black-start power source is increased.