Polyphase power control

Power control apparatus coupled to an n-phase voltage source for generating on a set of n lines a repeating sequence of time spaced power pulses, with each power pulse occurring at a controlled repetition rate and comprising a permutation of associated phase voltages on respective lines of said set, at least portions of said associated phase voltages being time coincident, said apparatus comprising:

• a. pulse-forming means coupled to said source for providing a series of timing pulses synchronized with each phase voltage of said source;
• b. circuit means responsive to said timing pulses for selectively providing a series of control pulses of said controlled repetition rate and having a predetermined duration, said circuit means including:
• i. counter means for providing an output pulse every predetermined integer number of phase pulses;
• ii. pulse generating means coupled to said counter means for generating said control pulses to have said predetermined durations and to be in a predetermined timed relationship with one of the phase voltages of said source;
• and,
• c. switching means, including a set of thyristor switches having respective outputs coupled to said set of lines, and having respective control inputs responsive to each of said control pulses, for communicating said associated phase voltages coinciding with said control pulses.

Power control apparatus providing on a set of lines a repeating sequence of power pulses from an n-phase AC voltage source of frequency F to an n-phase motor, each power pulse comprising on the set of lines a permutation of at least portions of associated and successive half-cycle phase voltages of said source, said power pulses applied to the motor at a predetermined pulse repetition rate and according to a predetermined permutation of the phase voltages for effecting one revolution of the motor per sequence, thereby at a frequency less than F, comprising:

• a. pulse-forming means coupled to said voltage source for providing a series of timing pulses representing each zero level voltage crossing of each phase voltage of the source;
• b. circuit means responsive to said timing pulses for selectively providing a series of energizing pulses of said predetermined repetition rate and having a pulse duration which is time coincident with at least one of the timing pulses;
• and,
• c. switching means, including a plurality of thyristor switches coupling said source and said motor and all having respective control inputs responsive to each energizing pulses, for communicating the phase voltages coinciding with said energizing pulses.

A method of controlling the speed of a poly-phase motor driven by a polyphase voltage on a set of lines from an n-phase voltage source of frequency F comprising the steps of:

• a. generating a first sequence of timing pulses corresponding to every zero level voltage crossing of every phase voltage of said source;
• b. generating an energizing pulse having a predetermined pulse width every predetermined integer number of timing pulses;
• and,
• c. coupling all phase voltages of the polyphase source to said motor during intervals corresponding to the occurrence of said energizing pulses.

A method for controlling the speed of a poly-phase motor driven by a polyphase voltage on a set of lines from an n-phase voltage source comprising the steps of:

• a. generating a first sequence of timing pulses corresponding to every zero level voltage crossing of every phase voltage of said source;
• b. establishing a predetermined integer number of pulses, said integer number varying with motor speed desired;
• c. generating an energizing pulse having a predetermined pulse width every said predetermined integer number of pulses of said first sequence;
• d. selectively coupling all phase voltages of the polyphase source to said motor during intervals corresponding to the occurrence of said energizing pulses, thereby coupling intermittent sequence of at least portions of associated phase voltages of said source to said motor;
• and,
• e. thereafter varying said predetermined integer number in accordance with motor speed desired.

Power control apparatus coupled to an n-phase voltage source for generating on a set of lines a repeating sequence of time spaced groups of phase voltage of said source to a load, with each group comprising a permutation of at least portions of phase voltages associated in time on said set of lines, comprising:

• a. pulse-forming means coupled to said voltage source for providing a series of timing pulses synchronized with each phase voltage of the voltage source;
• b. circuit means responsive to said timing pulses for selectively providing a series of energizing pulses, each pulse having a predetermined duration;
• c. switching means coupled to said source and having a set of control inputs responsive to each energizing pulse for communicating the phase voltages on all said lines coinciding with each of said energizing pulses;
• and,
• d. feedback means coupled to said circuit means and responsive to power consumed by said load for establishing the magnitude of said predetermined duration.

Power control apparatus coupled to an n-phase voltage source for generating on a set of lines a repeating sequence of groups of phase voltage of said source to a load, with each group comprising a permutation of at least portions of phase voltages associated in time on said set of lines, comprising:

• a. pulse-forming means coupled to said voltage source for providing a series of timing pulses synchronized with each phase voltage of the voltage source;
• b. circuit means responsive to said timing pulses for selectively providing a series of energizing pulses at a predetermined repetition rate;
• c. switching means coupled to said source and having a set of control inputs responsive to each energizing pulse for communicating the phase voltages on all said lines coinciding with each of said energizing pulses;
• and,
• d. feedback means coupled to said circuit means and responsive to power consumed by said load for establishing the magnitude of said predetermined repetition rate.

Power control apparatus coupled to a polyphase voltage source for generating on a set of lines a repeating sequence of time spaced power pulses, with each power pulse comprising a selected number of, and permutation of, at least portions of time coincident phase voltages on said set of lines from said source, comprising:

• a. pulse-forming means coupled to said source for providing a series of timing pulses in response to phase voltages from such source, said timing pulses being synchronized with each phase voltage from said polyphase source;
• b. a controller responsive to said timing pulses for selectively providing a series of energizing pulses, each energizing pulse having a predetermined duration;
• c. power switch means coupled to said source and having a set of control inputs responsive to each of said energizing pulses for communicating phase voltages on said set of lines coinciding with each said energizing pulse;
• and,
• d. said controller having means for varying said predetermined duration to thereby vary the selected number of phase voltages in each group of power pulses.

Power control apparatus for coupling a repeating sequence for groups of phase voltages associated in time on a set of lines and at a controlled repetition rate from a polyphase voltage source to a polyphase motor, each said group having a selected number of and a selected permutation of at least portions of each phase voltage of said source, thereby to effect one revolution of said motor per sequence, comprising:

• a. pulse-forming means coupled to said source and responsive to the phase voltages of said source for providing a series of timing pulses synchronized with each phase voltage;
• b. a controller responsive to said timing pulses for selectively providing a series of energizing pulses of said controlled repetition rate, with each control pulse having a selectable pulse width;
• c. power switch means coupled to said source and having a set of control inputs responsive to each said energizing pulses for communicating all phase voltages on said lines coinciding with said energizing pulses;
• and,
• d. said controller having means for varying said pulse width to thereby vary the selected number of phase voltages in each group.

A method for controlling the cyclic excitation of a polyphase load by a polyphase voltage source comprising the steps of:

• a. generating a first sequence of timing pulses corresponding to every zero level voltage crossing of every phase voltage of said source;
• b. establishing a predetermined integer number of timing pulses, said integer number varying with the desired rate of cyclic load excitation;
• c. generating an energizing pulse having a selected pulse width every said predetermined integer number of pulses;
• d. coupling all phase voltages of the polyphase source to said polyphase load during intervals corresponding to the occurrence of said energizing pulses, thereby intermittently coupling a selected sequence of groups of at least portions of time coincident phase voltage to said load;
• and,
• e. varying said selected pulse width in accordance with different desired rates of cyclic excitation.