MV network earth fault parameters measurement as factor supporting quality of network operation in case of renewable sources presence

Abstract

Security of supply and reliability of distribution network operation play the important role in power systems incorporating renewable energy sources. The requirements for reduction of SAIDI and SAIFI indexes imposed on distribution network operators result in intensive research being directed towards the development of modern methods able to ensure the improved continuity of customer supply. One of the effective ways to grant better network operation conditions is the improvement of earth fault current compensation adjustment and the correction of earth fault protection settings. The evaluation of network operating conditions and the proper selection of neutral point grounding parameters should be carefully conducted especially in the case of wind farm connections to the network. For this purpose, an innovative, non-invasive method of measuring network earth fault parameters has been developed. In result a portable device, named MPZ, able to measure the network earth-fault parameters was constructed. The measurement results conducted by use of the created meter form the solid base for proper selection of neutral point grounding ways and can effectively improve the quality of network earth fault current compensation and of earth fault current compensation coils adjustment. These improvements directly translate into increased reliability of the distribution network operation.