Feedback control of an inverter output bridge and motor system

A three phase inverter feedback mechanism, comprising:

• a direct current power source having a positive output terminal and a negative output terminal;
• an inverter output bridge wherein direct current input power is converted to variable three phase alternating current output power comprised of a first insulated gate bipolar transistor having a gate, a collector and an emitter;
• a second insulated gate bipolar transistor having a gate, a collector and an emitter;
• a third insulated gate bipolar transistor having a gate, a collector and an emitter;
• a fourth insulated gate bipolar transistor having a gate, a collector and an emitter;
• a fifth insulated gate bipolar transistor having a gate, a collector and an emitter;
• a sixth insulated gate bipolar transistor having a gate, a collector and an emitter;
• a positive power input terminal;
• a negative power input terminal;
• a first three phase alternating current output terminal;
• a second three phase alternating current output terminal;
• and a third three phase alternating output terminal wherein said collector of said first insulated gate bipolar transistor, said collector of said second insulated gate bipolar transistor, and said collector of said third insulated gate bipolar transistor are connected to said positive power input terminal;
• said emitter of said fourth insulated gate bipolar transistor, said emitter of said fifth insulated gate bipolar transistor, and said emitter of said sixth insulated gate bipolar transistor are connected to said negative power input terminal;
• said emitter of said first insulated gate bipolar transistor is connected to said collector of said fourth insulated gate bipolar transistor and to said first three phase alternating current output terminal;
• said emitter of said second insulated gate bipolar transistor is connected to said collector of said fifth insulated gate bipolar transistor and to said second three phase alternating current output terminal;
• and said emitter of said third insulated gate bipolar transistor is connected to said collector of said sixth insulated gate bipolar transistor and to said third three phase alternating current output terminal;
• a three phase induction motor connected to said first three phase alternating current output terminal, said second three phase alternating current output terminal, and said third three phase alternating current output terminal;
• a positive direct current link connected between said positive output terminal of said direct current power source and said positive power input terminal of said inverter output bridge wherein the current in said positive direct current link is positive when flowing into said positive power input terminal of said inverter output bridge and negative when flowing out of said positive power input terminal of said inverter output bridge;
• a negative direct current link connected between said negative output terminal of said direct current power source and said negative power input terminal of said inverter output bridge wherein the current in said negative direct current link is positive when flowing out of said negative power input terminal of said inverter output bridge and negative when flowing into said negative direct current input terminal of said inverter output bridge;
• means for generating a first logic signal wherein said first logic signal has a first logic value when the current in said negative direct current link is positive and a second logic value when the current in said negative direct current link is not positive;
• means for generating a second logic signal wherein said second logic signal has said first logic value when the current in said negative direct current link is negative and said second logic value when the current in said negative direct current link is not negative;
• means for combining said first logic signal and said second logic signal to generate a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal, and a sixth control signal wherein each of said first, second, third, fourth, fifth and sixth control signals depends on the amount of time said current in said negative direct current link is positive and the amount of time said current in said negative direct current link is negative;
• and
• electrical connections between said first control signal and said gate of said first insulated gate bipolar transistor, said second control signal and said gate of said second insulated gate bipolar transistor, said third control signal and said gate of said third insulated gate bipolar transistor, said fourth control signal and said gate of said fourth insulated gate bipolar transistor, said fifth control signal and said gate of said fifth insulated gate bipolar transistor, and said sixth control signal and said gate of said sixth insulated gate bipolar transistor.