Comparative Study on Dynamic Reactive Power Compensation Scheme in the Concentrated Delivery Area of New Energy in Southern Qinghai

To solve the problem of transient overvoltage occurred in the centralized delivery of high proportion new energy in southern Qinghai, a new dynamic reactive power compensation scheme based on distributed synchronous condensers was proposed. By means of contrastive analysis on different dynamic reactive power compensation devices and connecting modes during typical DC faults, an optimal dynamic reactive power compensation scheme was filtrated for the over-voltage suppression and low-voltage support capability of buses in new energy station. Results of the research show that the scheme, in which the 35kV bus bar or the 110kV gathering station in new energy station are connected with distributed synchronous condenser via three-winding transformer, possesses a better effect of reactive power compensation. Overally considering the cost of the step-up transformer and that of unit capacity of the synchronous condenser, the proposed scheme is of economic advantages.