respective inputs and set points to i maintain the voltage differential between neutral 20 c and ground 32 constant as defined above at 0 volts and ii maintain the voltage differential between positive voltage 20 a and neutral 20 b and negative voltage 20 c and neutral 20 b at a constant as defined above system voltage differential e g 190 volts and u2212 190 volts referring again to fig5 5 a and 6 these figures show the circuitry of embodiments of dc to dc converters with neutral point balancing by using high frequency control of the central semiconductor device units fig5 and 5a elements 100 a 100 b 102 and 106 and fig6 components 170 a 170 b 172 and 176 the input bus is balanced which maintains two independent voltage rails relative to neutral and neutral point regulator maintains the neutral point to 0v relative to ground the neutral balancing circuitry allows for constant voltage to ground of the system this voltage is maintained both under normal operating conditions and under fault conditions by maintaining the neutral voltage the system is allowed to respond in a similar way to an alternating current system when a fault occurs this permits a protective device to clear and the system to return to normal operation after the fault has occurred in the preferred embodiments described in fig5 5 a 6 and 10 the switches are insulated gate bipolar transistors alternative switching components e g alternate semiconductor switches field effect transistors etc can be used for components 100 a 100 b.