The large-scale integration of distributed energy resources through power electronics devices comes along with an increasing challenge of maintaining overall system stability and high power quality standards. Grid-connected power converters are increasingly required to participate in grid support and control while being subjected to even more stringent requirements regarding converter control and operation. Among the various control methods, Hysteresis Current Controllers (HCC) are still quite popular due to their simple implementation, fast transient response and robustness. On the downside, power converters with HCC are compromised by stochastic variable switching frequencies. While low order frequency components lead to resonance oscillations, those of higher order are equally undesired due to significant thermal loading. Especially in high-power applications, control over the switching frequency is desired. In this work, a novel control approach based on a variable hysteresis bandwidth is proposed to achieve a nearly constant average switching frequency. Additional state feedback controller are implemented for active resonance damping. A thorough simulation study as well as experimental investigations show the dynamic performance of the proposed control scheme.
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