Effect of Capacitor Voltage Ripples on Submodule Active Power Control Limits of Cascaded Multilevel Converters

In the operation of cascaded H-bridge converters and modular multilevel with energy storage or renewable power resources, unbalanced active distribution among submodules (SMs) is unavoidable. Depending on operating conditions, there are certain upper lower limits that can be processed by a single SM subset SMs. The control system needs to restrict references these limits, hence, accurate knowledge important. existing methods derive capacitor voltages assumed have negligible ripples, whereas in practice ripples considerable. This article analyzes effect voltage highlights importance considering ripple effect. A methodology proposed accurately incorporate derivation limits. Simulation experimental results provided evaluate effectiveness methodology.