Boost Modular Multilevel Converter’s Capacitor Voltage Balancing without voltage sensors

In this paper a cross connected half ridge sub-module (XCHB-SM) based modular multilevel converter (MMC) is presented. It is capable to block DC side fault which is not possible with normal HB-SM based MMC. MMC is also prominent for its superior Capacitor Voltage Balancing (CVB). But with the conventional CVB, voltage sensors needed is equal to the number of capacitors in addition with two current sensors for efficacious operation of balancing algorithm. Comparatively high cost of the voltage sensors again leads to the matter of concern and hence avoiding use of voltage sensors will reduce the cost of the converter. This paper mainly concerns about the voltage balancing technique for capacitors in all the sub module capacitors using current sensors. Validation of the works is carried out using the Matlab simulation and hardware in the loop (by OP4510RT-lab-RCP/HIL).