The State of the Art of the Control Strategies for Single-Phase Electric Springs

The concept of electric springs (ESs) has been proposed as a new solution for stabilizing power grid fed by intermittent renewable energy sources. With a battery or active power source (DC, on the inside), the ESs can provide both active and reactive power compensations. So far, three typical topologies of single-phase ESs have been reported. Unlike traditional devices where power generation follows the load demand, the ESs are associated with non-critical loads form the so-called smart loads that transfer the fluctuated power to the non-critical loads, adaptively, according to the intermittent nature of power generation. After reviewing the main control strategies of single-phase ESs, the paper analyzes their advantages and disadvantages as well as their suitable applications. Comparisons among different control strategies on a specific topology version are implemented. Finally, conclusions and possible future trends are pointed out