Multiphase inverter system with phase reversal

Claim 2

AN INVERTER SYSTEM SUPPLIED FROM A SOURCE OF DIRECT CURRENT AND PROVIDING A THREE-PHASE OUTPUT VOLTAGE WITH REVERSIBLE PHASE ORDER COMPRISING: A THREE-PHASE INVERTER COMPRISING THREE HALF-BRIDGES EACH COMPRISING TWO LEGS AND CONNECTED IN PARALLEL WITH ONE ANOTHER ACROSS SAID SOURCE OF DIRECT CURRENT; FIRST CONTROL MEANS COMPRISING PILOT CIRCUITS FOR EACH OF SAID HALF-BRIDGES ENERGIZABLE IN A SEQUENCE TO RENDER SAID LEGS CONDUCTIVE IN A CORRESPONDING FIRST SEQUENCE FOR PRODUCING A FIRST PHASE SEQUENCE IN SAID THREE-PHASE OUTPUT VOLTAGE; AND SECOND CONTROL MEANS FOR AT LEAST TWO SAID THREE HALFBRIDGES COMPRISING ADDITIONAL PILOT CIRCUITS FOR THE ASSOCIATED HALF-BRIDGES AND ENERGIZABLE IN A SEQUENCE WITH THE OPERABLE PILOT CIRCUITS FOR ALL OF SAID THREE HALF-BRIDGES FOR RENDERING SAID LEGS CONDUCTIVE IN A DIFFERENT CORRESPONDING SEQUENCE FOR PRODUCING A SECOND PHASE SEQUENCE IN SAIS THREE-PHASE OUTPUT VOLTAGE; SAID FIRST AND SECOND FIRING CONTROL MEANS BEING ALTERNATELY AND SELECTIVELY OPERABLE TO REVERSE THE PHASE SEQUENCE OF SAID THREE-PHASE OUTPUT.

Claim 3

A THREE-PHASE REVERSIBLE ALTERNATING CURRENT MOTOR CONTROL SYSTEM COMPRISING: A THREE-PHASE REVERSIBLE ALTERNATING CURRENT MOTOR; A THREE-PHASE VARIABLE FREQUENCY INVERTER FOR SUPPLYING POWER TO SAID MOTOR COMPRISING THREE HALF-BRIDGES EACH COMPRISING TWO LEGS AND CONNECTED IN PARALLEL WITH ONE ANOTHER ACROSS SAID SOURCE OF DIRECT CURRENT, THE FREQUENCY OF THE OUTPUT OF SAID INVERTER BEING SUBSTANTIALLY DETERMINATIVE OF THE MOTOR SPEED; FIRST CONTROL MEANS COMPRISING PILOT CIRCUITS FOR EACH OF SAID LEGS OF EACH OF SAID HALF-BRIDGES BEING ENERGIZABLE IN A SEQUENCE TO RENDER SAID LEGS CONDUCTIVE IN A CORRESPONDING FIRST SEQUENCE FOR PRODUCING A FIRST PHASE SEQUENCE IN SAID THREE-PHASE OUTPUT VOLTAGE; SECOND CONTROL MEANS FOR AT LEAST TWO OF SAID THREE HALF-BRIDGES COMPRISING ADDITIONAL PILOT CIRCUITS FOR THE ASSOCIATED LEGS OF SAID HALF-BRIGES AND ENERGIZABLE IN A SEQUENCE WITH THE OPERABLE PILOT CIRCUITS FOR ALL OF SAID THREE HALF-BRIDGES FOR RENDERING SAID LEGS CONDUCTIVE IN A DIFFERENT CORRESPONDING SEQUENCE FOR PRODUCING A SECOND PHASE SEQUENCE IN SAID THREEPHASE OUTPUT VOLTAGE; SWITCHING MEANS FOR MAKING SAID FIRST AND SECOND CONTROL MEANS ALTERNATELY OPERABLE; AND SPEED SENSITIVE MEANS RESPONSIVE TO A CONDITION INDICATIVE OF THE SPEED OF SAID MOTOR FOR CONTROLLING SAID SWITCHING MEANS AND FOR PERMITTING SAID SWITCHING MEANS TO CHANGE THE STATE OF OPERABILITY OF SAID FIRST AND SECOND CONTROL MEANS ONLY AT RELATIVELY LOW MOTOR SPEEDS, WHEREBY REVERSAL OF PHASES MAY BE ACCOMPLISHED AT ONLY RELATIVELY LOW MOTOR SPEEDS.

Claim 4

A THREE-PHASE REVERSIBLE ALTERNATING CURRENT MOTOR CONTROL SYSTEM COMPRISING: A THREE-PHASE REVERSIBLE ALTERNATING CURRENT MOTOR; A THREE-PHASE VARIABLE FREQUENCY INVERTER FOR SUPPLYING POWER TO SAID MOTOR COMPRISING THREE HALF-BRIDGES EACH COMPRISING TWO LEGS AND CONNECTED IN PARALLEL WITH ONE ANOTHER ACROSS SAID SOURCE OF DIRECT CURRENT, THE FREQUENCY OF THE OUTPUT OF SAID INVERTER BEING SUBSTANTIALLY DETERMINATIVE OF THE MOTOR SPEED; FIRST CONTROL MEANS COMPRISING PILOT CIRCUITS FOR EACH OF SAID LEGS OF EACH OF SAID HALF-BRIDGES BEING ENERGIZABLE IN A SEQUENCE TO RENDER SAID LEGS CONDUCTIVE IN A CORRESPONDING FIRST SEQUENCE FOR PRODUCING A FIRST PHASE SEQUENCE IN SAID THREE-PHASE OUTPUT VOLTAGE; SECOND CONTROL MEANS FOR AT LEAST TWO OF SAID THREE HALF-BRIDGES COMPRISING ADDITIONAL PILOT CIRCUITS FOR THE ASSOCIATED LEGS OF SAID HALF-BRIGES AND ENERGIZABLE IN A SEQUENCE WITH THE OPERABLE PILOT CIRCUITS FOR ALL OF SAID THREE HALF-BRIDGES FOR RENDERING SAID LEGS CONDUCTIVE IN A DIFFERENT CORRESPONDING SEQUENCE FOR PRODUCING A SECOND PHASE SEQUENCE IN SAID THREEPHASE OUTPUT VOLTAGE; SWITCHING MEANS FOR MAKING SAID FIRST AND SECOND CONTROL MEANS ALTERNATELY OPERABLE; AND SPEED SENSITIVE MEANS RESPONSIVE TO A CONDITION INDICATIVE OF THE SPEED OF SAID MOTOR FOR CONTROLLING SAID SWITCHING MEANS AND FOR PERMITTING SAID SWITCHING MEANS TO CHANGE THE STATE OF OPERABILITY OF SAID FIRST AND SECOND CONTROL MEANS ONLY AT RELATIVELY LOW MOTOR SPEEDS, WHEREBY REVERSAL OF PHASES MAY BE ACCOMPLISHED AT ONLY RELATIVELY LOW MOTOR SPEEDS.