Operation analysis of bipolar DC distribution system with new half-bridge voltage balancer

This paper describes a bipolar DC distribution system with a new half-bridge voltage balancer which can adjust the unequal voltage between the positive and the negative poles. The half-bridge voltage balancer has two cascaded voltage and current controls for adjusting the terminal voltage unbalance due to the unequal load size. The operation of typical bipolar DC distribution system, which consists of a grid-tied converter, a new half-bridge voltage balancer, a PV generator, a battery energy storage, a super-cap energy storage, and two DC loads with different capacity, was analyzed by computer simulations. A scaled prototype of typical bipolar DC distribution system was manufactured and tested to confirm the simulation results. The new half-bridge voltage balancer with two cascaded voltage and current controls could be applied for the actual bipolar DC distribution system.