Research on Fault Ride-through Strategy of New Energy Through Flexible Direct Current Grid Connection
In case of fault in AC system,the new energy transmission system through flexible direct current shall possess the fault ride through capability so to achieve safe and reliable operation of new energy flexible direct current transmission system.For solving this problem,a kind of fault ride through control strategy based on fault current limitation is proposed.Firstly,an overview of the pilot project of new energy through flexible direct current grid connection is introduced.Then,the fault ride through control strategy including such chains as reactive power-voltage sag controller,active-frequency sag controller and current limiting controller is introduced in detail.After that,the pilot project model is set up under PSCAD/EMTDC environment and the fault ride through strategy of the new energy converter station VSC2 is simulated and verified.The simulation result shows that after the single phase ground fault,neither the station control nor valve control protection operates and the influence of the fault on VSC1 station is less.Although the transmission power of VSC2 station drops dramatically during the fault period,yet after the clearance of the fault the DC voltage and AC voltage can be able to recover gradually to the normal operation condition.Finally,the effectiveness of the control strategy proposed in this paper is verified by way of comparing with the site fault test data of new energy transmission through flexible direct current in Hubei Province.
flexible direct current transmissionnew energyfault ride-throughsag controlpilot project
万方数据
维普
