Review of Electric Spring: A new smart grid device for efficient demand dispatch and active and reactive power control

This paper deals with theory, modeling, applications and limitations of an Electric Spring (ES) by reviewing the published literature in this area. An ES, a custom power device (power electronic converter), is gradually emerging as an eminent member of smart grid. It provides stability to the grid, by controlling real and reactive power so as to regulate voltage of the grid and is considered to be operating under the influence of intermittent and unpredictable renewable energy sources (RES). ES is connected in between grid and load and hence it can damp out the oscillations of the grid. Load is bifurcated into groups based on its tolerable voltage range. Critical load is required to have constant voltage profile with no tolerance to voltage variation and non-critical load can have this tolerance in a widely specified band so as to swing along the power pattern of RES. Optimally dispersed Electric Springs throughout the grid can provide stability while acting in unison. Operation of ES effectively caters the requirement of demand side management.