A power conversion system (5; 10; 40; 50; 60; 70) comprising: (a) a plurality of n converters (18, 20a-20c), each of the n converters (18, 20a-20c) having a three-phase converter output voltage with three or more voltage levels, n being an integer that is greater than or equal to 3; (b) a plurality of n-1 phase-shifted transformers (22a-22c), each phase-shifted transformer (22a-22c) comprising an open star winding and a delta winding, and having a transformer electrical output, wherein during operation each phase-shifted transformer (22a-22c) has a phase-shift of (60/n)° between the delta winding and the open star winding; wherein the delta winding of each phase-shifted transformer (22a-22c) is directly electrically connected respectively to an i th converter (20a-20c), i being an integer in a range from 1 to n-1 inclusive, wherein the n th converter is directly electrically connected to the open star winding of the first phase-shifted transformer, wherein the open star winding of the (n-1) th phase-shifted transformer is directly electrically connected to a load and the open star winding of the i th phase-shifted transformer (22a, 22b) is directly electrically connected to the open star winding of the (i+1) th phase-shifted transformer (22b, 22c) such that the plurality of n-1 phase-shifted transformers (22a-22c) have a combined electrical output that is directed to the load; (c) a controller configured to operate a plurality of switches of one or more of the n converters (18, 22a-22c) and thereby modulate the output voltages of one or more converters such that fundamentals of the output voltages are additive and such that one or more harmonic orders produced by modulation of the output voltages are eliminated or reduced at the combined electrical output of the n-1 phase-shifted transformers (22a-22c), wherein the controller operates the plurality of switches of one or more of the n converters (18, 22a-22c) at a switching frequency less than 1 kHz, and preferably in the range of 500 to 800 Hz; and (d) one or more DC voltage sources configured to power the n converters (18, 20a-20c). (a) a plurality of n converters (18, 20a-20c), each of the n converters (18, 20a-20c) having a three-phase converter output voltage with three or more voltage levels, n being an integer that is greater than or equal to 3; (b) a plurality of n-1 phase-shifted transformers (22a-22c), each phase-shifted transformer (22a-22c) comprising an open star winding and a delta winding, and having a transformer electrical output, wherein during operation each phase-shifted transformer (22a-22c) has a phase-shift of (60/n)° between the delta winding and the open star winding; wherein the delta winding of each phase-shifted transformer (22a-22c) is directly electrically connected respectively to an i th converter (20a-20c), i being an integer in a range from 1 to n-1 inclusive, wherein the n th converter is directly electrically connected to the open star winding of the first phase-shifted transformer, wherein the open star winding of the (n-1) th phase-shifted transformer is directly electrically connected to a load and the open star winding of the i th phase-shifted transformer (22a, 22b) is directly electrically connected to the open star winding of the (i+1) th phase-shifted transformer (22b, 22c) such that the plurality of n-1 phase-shifted transformers (22a-22c) have a combined electrical output that is directed to the load; (c) a controller configured to operate a plurality of switches of one or more of the n converters (18, 22a-22c) and thereby modulate the output voltages of one or more converters such that fundamentals of the output voltages are additive and such that one or more harmonic orders produced by modulation of the output voltages are eliminated or reduced at the combined electrical output of the n-1 phase-shifted transformers (22a-22c), wherein the controller operates the plurality of switches of one or more of the n converters (18, 22a-22c) at a switching frequency less than 1 kHz, and preferably in the range of 500 to 800 Hz; and (d) one or more DC voltage sources configured to power the n converters (18, 20a-20c).