A regulator rectifier device comprising: a source terminal to receive a three phase alternating current voltage with each phase including a positive cycle and a negative cycle from a generating device; a plurality of first rectifying unit with a first gate terminal, connected to said generating device to rectify the positive cycle of said three phase alternating current voltage; a plurality of second rectifying unit with a second gate terminal, said second rectifying unit connected to said generating device to rectify the negative cycle of said three phase alternating current voltage, wherein said second rectifying unit switches between rectification mode and shunt mode depending on a load condition; and a controlling unit configured to control said second rectifying unit by a gate control signal, said controlling unit outputs said gate control signal based on an output voltage of said regulator rectifier device with respect to any one of a first predefined voltage in battery connected condition and a third predefined voltage in battery-less condition and said positive cycle and said negative cycle of each phase of said three phase alternating current voltage from said generating device, said gate control signal enables said second rectifying unit to switch between rectification mode and shunt mode by controlling the second gate terminal of said second rectifying unit, wherein said gate control signal switches said second rectifying unit into shunt mode when the output voltage of said regulator rectifier device is greater than any one of said first predefined voltage in battery connected condition and said third predefined voltage in battery-less condition, and thereby continuing the shunting of said second rectifying unit as long as said positive cycle of corresponding phase of said three phase alternating current voltage exists. a source terminal to receive a three phase alternating current voltage with each phase including a positive cycle and a negative cycle from a generating device; a plurality of first rectifying unit with a first gate terminal, connected to said generating device to rectify the positive cycle of said three phase alternating current voltage; a plurality of second rectifying unit with a second gate terminal, said second rectifying unit connected to said generating device to rectify the negative cycle of said three phase alternating current voltage, wherein said second rectifying unit switches between rectification mode and shunt mode depending on a load condition; and a controlling unit configured to control said second rectifying unit by a gate control signal, said controlling unit outputs said gate control signal based on an output voltage of said regulator rectifier device with respect to any one of a first predefined voltage in battery connected condition and a third predefined voltage in battery-less condition and said positive cycle and said negative cycle of each phase of said three phase alternating current voltage from said generating device, said gate control signal enables said second rectifying unit to switch between rectification mode and shunt mode by controlling the second gate terminal of said second rectifying unit, wherein said gate control signal switches said second rectifying unit into shunt mode when the output voltage of said regulator rectifier device is greater than any one of said first predefined voltage in battery connected condition and said third predefined voltage in battery-less condition, and thereby continuing the shunting of said second rectifying unit as long as said positive cycle of corresponding phase of said three phase alternating current voltage exists.