Improving Dynamic Response of Grid-Connected Converters with Electronic DC Links

An Electronic Capacitor (EC) is a bidirectional DCDC converter that utilizes a small auxiliary capacitance and mimics the low-frequency behavior of a different (typically much higher) capacitance. The well-known problem of using the electronic capacitor as an alternative to an electrolytic one is its poor ability to withstand step load changes. This paper proposes a novel approach to achieve better dynamic behavior of an EC, improving its ability to withstand sudden load changes while maintaining total harmonic distortion (THD) and DC-link voltage undershoot (US) standards of the grid. PSIM simulations are presented to support the validity of the proposed methodology.