A modular system for assembling a power system architecture comprising: a common power module having a direct current, DC, input/output and an alternating current,AC, input/output, wherein the common power module includes at least a four-leg power bridge, a controller module, and a first communications port coupled with the controller module and a second communications port coupled with the controller module, and the controller module is communicatively coupled with the four-leg power bridge and configured to operate the four-leg power bridge to at least one of invert DC power received at the DC input/output to AC power provided to the AC input/output, or to convert AC power received at the AC input/output to DC power provided to the DC input/output, wherein components for a fourth leg of the four-leg power bridge are configured to be selectively enabled or selectively operable; an exciter power module having a second DC input configured to connect to the DC input/output and a second AC output configured to be coupled with a generator or a starter/ generator, and wherein the exciter power module includes a fifth communications port wherein the fifth communications port is configured to selectively couple with at least one of the first or second communication ports; and at least one of a DC output module having a first DC input and a DC output or an AC output module having an AC input and a first AC output; wherein the AC output module is a four-phase AC output/EMI module that includes a set of power filtering elements and wherein the fourth leg defines or is electrically coupled with a neutral or ground connection; wherein the first DC input is configured to connect to the DC input/output or the AC input/output is configured to connect to one of the AC input, an AC input/output of a second common power module, or an AC generator output. a common power module having a direct current, DC, input/output and an alternating current,AC, input/output, wherein the common power module includes at least a four-leg power bridge, a controller module, and a first communications port coupled with the controller module and a second communications port coupled with the controller module, and the controller module is communicatively coupled with the four-leg power bridge and configured to operate the four-leg power bridge to at least one of invert DC power received at the DC input/output to AC power provided to the AC input/output, or to convert AC power received at the AC input/output to DC power provided to the DC input/output, wherein components for a fourth leg of the four-leg power bridge are configured to be selectively enabled or selectively operable; an exciter power module having a second DC input configured to connect to the DC input/output and a second AC output configured to be coupled with a generator or a starter/ generator, and wherein the exciter power module includes a fifth communications port wherein the fifth communications port is configured to selectively couple with at least one of the first or second communication ports; and at least one of a DC output module having a first DC input and a DC output or an AC output module having an AC input and a first AC output; wherein the AC output module is a four-phase AC output/EMI module that includes a set of power filtering elements and wherein the fourth leg defines or is electrically coupled with a neutral or ground connection; wherein the first DC input is configured to connect to the DC input/output or the AC input/output is configured to connect to one of the AC input, an AC input/output of a second common power module, or an AC generator output.