Inspecting Cascaded Boost Configuration Linking LVDC and CDC Bus in DC Microgrid

To enhance the reliability and uninterrupted power supply of direct current (DC) microgrid, a generic practise is to connect the low voltage DC (LVDC) bus of individual households to the community DC (CDC) bus using power converters with high voltage gain ability. The cascaded connection of boost converters is an apposite choice for this application. However, multiple switch sequence as well as switching frequency operation of the power stages make the modelling analysis ravel. Moreover, existence of right half plane zeros in the required transfer functions of control to output variables governs the controller design process. This paper makes an effort to simplify the design analysis by incorporating the averaged switch model in the modelling procedure. An averaged small signal model (ASSM) is designed for the cascaded power structure considering inductor ripple information and ramp compensation slope for the mixedsignal peak current mode control algorithm. The derived model is verified with simulink circuit model(SCM) considering different switching sequence and switching frequencies in operation. A detailed controller design process and stability analysis is practised on the power topology. A laboratory prototype is developed to analyse the functionality of designed controllers form the derived model with consideration of steady state and transient operating conditions of the converters.