Methods and systems for controlling current source rectifiers

A current source rectifier (CSR) system for a power source including three phase lines, said CSR system comprising:

• a rectifier operable to receive an alternating current (AC) input voltage and provide a direct current (DC) output voltage, the rectifier comprising:
• a first phase leg comprising first and second series-coupled switches coupled between a positive line and a negative line, wherein first and second diodes correspond with the first and second switches, and wherein a first node coupled to a first phase line of the three phase lines is directly connected between the first switch and a cathode end of the second diode;
• a second phase leg comprising third and fourth series-coupled switches coupled between the positive line and the negative line, wherein third and fourth diodes correspond with the third and fourth switches, and wherein a second node coupled to a second phase line of the three phase lines is directly connected between the third switch and a cathode end of the fourth diode;
• and
• a third phase leg comprising fifth and sixth series-coupled switches coupled between the positive line and the negative line, wherein fifth and sixth diodes correspond with the fifth and sixth switches, and wherein a third node coupled to a third phase line of the three phase lines is directly connected between the fifth switch and a cathode end of the sixth diode;
• and
• a controller communicatively coupled to said rectifier and operable to:
• define a predetermined voltage range in a memory of the controller by hysteresis,
• control operation of said switches in accordance with a first switching sequence when measured input voltages on at least two phase lines of the three phase lines are outside of the predetermined voltage range, and
• control operation of said switches in accordance with a second switching sequence when the measured input voltages on the at least two phase lines are within the predetermined voltage range.