A system for converting a three-phase AC voltage to a 12-pulse DC voltage, comprising: a transformer (302,402,502,602) configured to convert a three-phase AC voltage (304,306,308; 404,406,408; 504,506,508; 604,606,608) into a first set of phase voltages (314,316; 414,416; 514,516; 614,616), a second set of phase voltages (318,320;418,420;518,520, 618,620), and a third set of phase voltages (322,324;422,424;522,524; 622,624); and a rectifier (336;436;536;636) comprising a first phase-leg (326;426;526; 626) electrically coupled to the first set of phase voltages (314,316; 414,416; 514,516; 614,616), a second phase-leg (328;428;528;628) electrically coupled to the second set of phase voltages (314,316; 414,416; 514,516; 614,616), and a third phase-leg electrically coupled to the third set of phase voltages (322,324;422,424; 522,524; 622,624), the system being configured such that the rectifier (336;436;536;636) sequentially cycles respective phase-legs into a 120 degree conducting state over a 360 degree cycle to output the 12-pulse DC voltage, characterized in that each of said phase legs comprises: a positive portion comprising a first positive diode, a second positive diode, and a main positive diode configured to conduct positive current towards a load, wherein the cathode of the first positive diode and the cathode of the second positive diode are electrically coupled to the anode of the main positive diode; and, a negative portion comprising a first negative diode, a second negative diode, and a main negative diode configured to conduct negative current from the load, wherein the cathode of the main negative diode is electrically coupled to the anode of the first negative diode and the anode of the second negative diode, wherein the system is configured such that the positive portion of a phase-leg conducts towards the load while the negative portion of a different phase leg conducts from the load to the transformer (302,402,502,602) during a 120 degree conducting state. a transformer (302,402,502,602) configured to convert a three-phase AC voltage (304,306,308; 404,406,408; 504,506,508; 604,606,608) into a first set of phase voltages (314,316; 414,416; 514,516; 614,616), a second set of phase voltages (318,320;418,420;518,520, 618,620), and a third set of phase voltages (322,324;422,424;522,524; 622,624); and a rectifier (336;436;536;636) comprising a first phase-leg (326;426;526; 626) electrically coupled to the first set of phase voltages (314,316; 414,416; 514,516; 614,616), a second phase-leg (328;428;528;628) electrically coupled to the second set of phase voltages (314,316; 414,416; 514,516; 614,616), and a third phase-leg electrically coupled to the third set of phase voltages (322,324;422,424; 522,524; 622,624), the system being configured such that the rectifier (336;436;536;636) sequentially cycles respective phase-legs into a 120 degree conducting state over a 360 degree cycle to output the 12-pulse DC voltage, characterized in that each of said phase legs comprises: a positive portion comprising a first positive diode, a second positive diode, and a main positive diode configured to conduct positive current towards a load, wherein the cathode of the first positive diode and the cathode of the second positive diode are electrically coupled to the anode of the main positive diode; and, a negative portion comprising a first negative diode, a second negative diode, and a main negative diode configured to conduct negative current from the load, wherein the cathode of the main negative diode is electrically coupled to the anode of the first negative diode and the anode of the second negative diode, wherein the system is configured such that the positive portion of a phase-leg conducts towards the load while the negative portion of a different phase leg conducts from the load to the transformer (302,402,502,602) during a 120 degree conducting state. a positive portion comprising a first positive diode, a second positive diode, and a main positive diode configured to conduct positive current towards a load, wherein the cathode of the first positive diode and the cathode of the second positive diode are electrically coupled to the anode of the main positive diode; and, a negative portion comprising a first negative diode, a second negative diode, and a main negative diode configured to conduct negative current from the load, wherein the cathode of the main negative diode is electrically coupled to the anode of the first negative diode and the anode of the second negative diode, wherein the system is configured such that the positive portion of a phase-leg conducts towards the load while the negative portion of a different phase leg conducts from the load to the transformer (302,402,502,602) during a 120 degree conducting state.