NOVELTY - The method involves computing a voltage regulation threshold based on output voltage for a power conversion module e.g. inverter (106). Input voltage of the power conversion module is compared to the voltage regulation threshold. Average input voltage less than the voltage regulation threshold is generated from the input voltage when the input voltage satisfies the voltage regulation threshold by driving a switch e.g. n-type MOSFET switch. A switching rate is determined based on the input voltage for driving the switch.    USE - Method for regulating input voltage to a power conversion module e.g. power converter such as inverter e.g. current source inverter, receiving direct current (DC) power from a renewable energy source e.g. wind farm and hydroelectric system, in a large-scale solar power generation system in a utility-scale installation for generating AC power for a AC commercial power grid and a commercial power company to run an appliance at a home and a business. Can also be used for a voltage source inverter (VSI) and a DC-DC power converter.    ADVANTAGE - The method enables utilizing an input voltage regulator to provide fully symmetric switching that reduces the input voltage to a DC-AC inversion stage and to eliminate common mode current to the AC commercial power grid, so that the inverter is balanced, thus reducing either conducted or radiated common mode emissions. The method enables regulating the input voltage by periodically activating/deactivating the switch that controls current flow from panels to the inverter, so that desired average input voltage to the inverter is achieved.    DETAILED DESCRIPTION - The output voltage is lowest rectified line-to-line voltage of an alternating current (AC) line coupled to the power conversion module. The switch is driven using pulse width modulation (PWM), space vector PWM and predictive modulation. The voltage regulation threshold is equal to difference between the output voltage and a margin. INDEPENDENT CLAIMS are also included for the following:    (1) an apparatus for regulating input voltage to a power conversion module    (2) a system for regulating input voltage.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of a solar power generation system.    Solar power generation system (100)    Photovoltaic modules (102-1-102-M)    Panels (104-1-104-N)    Inverter (106)    Input voltage regulator (110)