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An alternating current motor control system constituted of: a control unit; a cycloconverter functionality; a phase control functionality; and a semiconductor switching unit comprising a plurality of electronically controlled semiconductor switches each associated with a particular winding of a targ

An alternating current motor control system constituted of: a control unit; a cycloconverter functionality; a phase control functionality; and a semiconductor switching unit comprising a plurality of electronically controlled semiconductor switches each associated with a particular winding of a target alternating current motor and each independently responsive to the control unit. In one embodiment the semiconductor switching unit is arranged to connect the windings of the target alternating current motor to a three phase power input in one of a star and a delta configuration responsive to the control unit.

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1. An alternating current (AC) motor control system arranged to control a target AC motor, the target AC motor arranged to receive a three phase AC power, the target AC motor having: a first winding, a first end of the first winding arranged to be coupled to a first phase of the three phase AC power

1. An alternating current (AC) motor control system arranged to control a target AC motor, the target AC motor arranged to receive a three phase AC power, the target AC motor having: a first winding, a first end of the first winding arranged to be coupled to a first phase of the three phase AC power; a second winding, a first end of the second winding arranged to be coupled to a second phase of the three phase AC power; and a third winding, a first end of the third winding arranged to be coupled to a third phase of the three phase AC power, the AC motor control system comprising: a control unit;a cycloconverter functionality;a phase control functionality; anda semiconductor switching unit comprising a plurality of electronically controlled semiconductor switches each independently responsive to said control unit, said plurality of electronically controlled semiconductor switches comprising: a first pair of anti-parallel connected thyristors, a first end of said first pair arranged for connection to a second end of the first winding, and a second end of said first pair arranged for connection to the third phase of the three phase AC power;a second pair of anti-parallel connected thyristors, a first end of said second pair arranged for connection to a second end of the second winding, and a second end of said second pair arranged for connection to the first phase of the three phase AC power; anda third pair of anti-parallel connected thyristors, a first end of said third pair arranged for connection to a second end of the third winding, and a second end of said third pair arranged for connection to the second phase of the three phase AC power,said control unit arranged to modulate the conduction period of said first pair, said second pair and said third pair responsive to a selectable one of said phase control functionality and said cycloconverter functionality. 2. The alternating current motor control system of claim 1, wherein said semiconductor switching unit further comprises 3 additional thyristors, each of the 3 additional thyristors associated with a particular one of the phases of the three phase AC power, said 3 additional thyristors arranged to connect the windings of the target AC motor to the three phase AC power in one of a star and a delta configuration responsive to said control unit. 3. The alternating current motor control system of claim 2, wherein said control unit is arranged in an operating condition of the target AC motor to set said 3 additional thyristors of said semiconductor switching unit to connect the windings of the target AC motor to the star configuration responsive to a predetermined condition of the rotational frequency and one of the current through two windings of the target AC motor and a static load torque of the target AC motor. 4. The alternating current motor control system of claim 3, wherein said control unit is arranged in an operating condition of the target AC motor to set said 3 additional thyristors of said semiconductor switching unit to connect the windings of the target AC motor to the delta configuration responsive to the absence of said predetermined condition. 5. The alternating current motor control system of claim 2, wherein said control unit is arranged in a start up condition of the target AC motor to: select the cycloconverter functionality so as to modulate the conduction period of said first pair, said second pair and said third pair of electronically controlled semiconductor switches responsive to said selected cycloconverter functionality. 6. The alternating current motor control system of claim 5, wherein said control unit is further arranged in a start up condition of the target AC motor to: set said 3 additional thyristors of said semiconductor switching unit to connect the windings of the alternating current motor to the three phase AC power in the delta configuration. 7. The alternating current motor control system of claim 1, wherein said control unit is arranged in an operating condition of the target AC motor to: compare the rotational frequency of the target AC motor with a set value; andin the event that said rotational frequency of the target AC motor is not equal to said set value, select the cycloconverter functionality so as to modulate the conduction period of said first pair, said second pair and said third pair of electronically controlled semiconductor switches responsive to said selected cycloconverter functionality. 8. The alternating current motor control system of claim 1, wherein said phase control functionality is arranged when selected in an operating condition of the target AC motor to modulate the conduction angle of said first pair, said second pair and said third pair of electronically controlled semiconductor switches so as to reduce energy consumption responsive to the relative torque. 9. The alternating current motor control system of claim 1, wherein said phase control functionality is arranged when selected in an operating condition of the target AC motor to modulate the conduction angle of said first pair, said second pair and said third pair of electronically controlled semiconductor switches, when selected, so as to reduce energy consumption responsive to the angle between an electromagnetic force vector of the target AC motor stator and a phase current of the target AC motor stator. 10. The alternating current motor control system of claim 1, further comprising: a means for receiving an indication of current through at least two of the windings of the target AC motor; anda means for receiving an indication of a voltage potential associated with said at least two windings of the target AC motor, said control unit further arranged to control said semiconductor switching unit responsive to said received indications of current and received indications of voltage potential. 11. The alternating current motor control system of claim 1, further comprising a passive filter arranged in parallel with each of the first, second and third windings of the target alternating current motor. 12. A method of controlling an alternating current three phase motor, the method comprising: providing a controller exhibiting a cycloconverter functionality and a phase control functionality;providing a semiconductor based switchable connection to a three phase power; andmodulating the conduction period of the constituent switches of said provided semiconductor based switchable connection responsive to a selectable one of said provided cycloconverter functionality and said provided phase control functionality. 13. The method of claim 12, further comprising: setting said switchable connection to connect the alternating current three phase motor to the three phase power in a star configuration responsive to a predetermined condition of the rotational frequency and one of the winding current and static load torque. 14. The method of claim 13, further comprising: setting said switchable connection to connect the alternating current three phase motor to the three phase power in a delta configuration responsive to the absence of said predetermined condition of the rotational frequency and one of the winding current and static load torque. 15. The method of claim 12, further comprising in a start up condition of the alternating current three phase motor: modulating the conduction period of the constituent switches of said provided semiconductor based switchable connection responsive to said provided cycloconverter functionality. 16. The method of claim 15, further comprising in the start up condition of the alternating current three phase motor: setting said switchable connection to connect the alternating current three phase motor to the three phase power in a delta configuration. 17. The method of claim 12, further comprising in an operating condition of the alternating current three phase motor: comparing the rotational frequency of the target alternating current motor with a set value; andin the event that said rotational frequency of the target alternating current motor is not equal to said set value,modulating the conduction period of the constituent switches of said provided semiconductor based switchable connection responsive to said provided cycloconverter functionality. 18. The method of claim 12, further comprising in an operating condition of the alternating current three phase motor: modulating the conduction period of the constituent switches of said provided semiconductor based switchable connection responsive to said provided phase control functionality responsive to the relative torque. 19. The method of claim 12, further comprising in an operating condition of the alternating current three phase motor: modulating the conduction period of the constitutent switches of said provided semiconductor based switchable connection responsive to said provided phase control functionality responsive to the angle between the electromagnetic vector of the stator and the phase current of the stator. 20. The method of claim 12, further comprising filtering the voltage across the windings of the alternating current three phase motor.