Effect of inertia deficit on power system stability - synthetic inertia concepts analysis

摘要

The continued expansion of renewable energy sources share in the power generation mix continues to increase the proportion of generating units and consumer systems that are connected to the network via power electronic devices. These producers - in contrast to conventional synchronous generators - and consumers do not have a rotating mass with direct coupling to the electric system, which would be able to support the stability of the system by acting against the frequency changes. A possible solution is the implementation of synthetic (or artificial) inertia in the power control of non-synchronous generators. There is no direct contact between the rotation speed of moving parts and the grid frequency - such as modern wind turbines - of generating units connecting to the network via power electronic converters. Thereby there is no contribution to the net mechanical inertia, i.e., do not contribute to the inertia of the entire system. In the followings this paper will introduce the basic physical problem of the inertia deficit and give an outlook about the nowadays popular approaches. As a result some recommendations and remarks will be defined how to handle this issue effectively.