A symmetrical power system is provided that supplies a symmetrical power at an output power supply. The symmetrical power system comprises a first transformer and a second transformer which have identical transformer properties. The first and second transformers are each separately in communication with one of a first and second phase of an input power supply via corresponding first primary windings, and each separately in communication with one of a first and second phase of the output power supply via corresponding first secondary windings. The first and second transformers are connected in parallel between a input common conductor of the input power supply via corresponding second primary windings and an output common conductor connected the output power supply via corresponding second secondary windings. The first and second phases of the output power supply are inversely phased.

Methods, systems and apparatus for a controller for fast transient response, the controller including a linear compensation circuit for controlling output voltage during steady state operation and a non-linear control circuit to generate a non-linear signal during transient periods, only a first pulse of the non-linear signal is injected during each transient period. The combination linear and non-linear control provides stability and reduces delay times for fast transient response. The non-linear control circuit includes a step up and a step down non-linear control circuit for producing the non-linear signal with a short delay time when the load voltage is less or greater than the reference voltage. An embodiment includes an adaptive circuit or generating a current signal dependent on the load current, the current signal is combined with the output voltage to reduce the difference between the reference and output voltages.