The Research and Engineering Practice on the Protection and Control Method of the DG System

In order to promote the practice on the DG (distributed generation) technology, this paper introduces the theory research and engineering practice on the protection and control method of the DG system, based on an IDC DG engineering. The basic information and the characteristic of the engineering is described. The general control target and the operation mode under different condition is analyzed, considering the operative characteristics and the requirements of the power substation, the DG and the customer. The coordination scheme between the power grid, the DG and the load is proposed innovatively. The priority and the logical sequence of the control from different part are determined. The practical experiment proves that the protection and control system can provide reliable and efficient power and refrigeration supply for the IDC data central via the coordinated control method of the operation mode shift, SPAS (spare power automatic switchover), load transferring and the black-start, with the coordination of the power grid, the DG and the load. Under the extreme case that the outside power is totally lost, the power and refrigeration supply can be recovered within 155 seconds.