Research on the working principle and stability of CLC electric springs based on the impedance analysis method

Abstract

SummaryElectric springs are an important tool for microgrids to resist fluctuations introduced by renewable energy. Ensuring the stability of the electric spring itself and the system is an important condition for effectively achieving voltage stabilization and resisting fluctuations. To solve the stability judgment problem of electric springs in weak current networks, a CLC‐Electric Spring (CLC‐ES) stability judgment method based on impedance analysis was studied. The article first establishes the CLC‐ES topology model and control strategy. Then, the stability criterion of CLC‐ES was derived, and the basic relationship between system phase margin (PM) and noncritical load resistance was explored. Finally, simulation and experiments show that the stability criteria and control method proposed in this paper are correct, confirming the feasibility of improving the system PM by increasing the noncritical load modulus.