A system for converting power comprising: a plurality of modules each having an input and an output and being connected in series such that the output of any module is connected to the input of a subsequent module , at least one of the modules being connected to at least one DC power source that supplies power to the module ; one or more storage devices in connection with the at least one DC power source such that the at least one DC power source charges the storage devices ; voltage control circuitry in each module operable to switch the storage device between the input and the output in order to provide a maximum module voltage and a minimum module voltage; a compensator unit having an input and an output in series with the modules , the compensator unit including a storage device charged by series current within the system and including compensator voltage control circuitry to vary the voltage supplied between the input and output of the compensator unit ; a control unit in communication with the voltage control circuitry of each of the modules and the compensator unit to control the voltage between the inputs and outputs thereof; wherein the control unit is configured such that when the control unit operates the voltage control circuitry of a module to vary the supplied voltage by the module, the control unit applies, via the compensator voltage control circuitry , a corresponding but opposed change in the voltage supplied by the compensator unit and, between such variations, the control unit ramps up or down the voltage between the input and the output of the compensator unit to output a desired signal. a plurality of modules each having an input and an output and being connected in series such that the output of any module is connected to the input of a subsequent module , at least one of the modules being connected to at least one DC power source that supplies power to the module ; one or more storage devices in connection with the at least one DC power source such that the at least one DC power source charges the storage devices ; voltage control circuitry in each module operable to switch the storage device between the input and the output in order to provide a maximum module voltage and a minimum module voltage; a compensator unit having an input and an output in series with the modules , the compensator unit including a storage device charged by series current within the system and including compensator voltage control circuitry to vary the voltage supplied between the input and output of the compensator unit ; a control unit in communication with the voltage control circuitry of each of the modules and the compensator unit to control the voltage between the inputs and outputs thereof; wherein the control unit is configured such that when the control unit operates the voltage control circuitry of a module to vary the supplied voltage by the module, the control unit applies, via the compensator voltage control circuitry , a corresponding but opposed change in the voltage supplied by the compensator unit and, between such variations, the control unit ramps up or down the voltage between the input and the output of the compensator unit to output a desired signal. <EOS>