Harmonically modified twelve-pole inverter

Claim 1

A twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controlled independently of a source of DC input voltage, said apparatus comprising: bridge inverter means providing four separate sets of constantly phase displaced pole voltages in two set-pairs constituted by first and second set-pairs of three-phase pole output voltages; first neutralizing means connected to receive the pole voltages from the first set-pair, and second neutralizing means connected to receive the pole voltages from the second set-pair, said first neutralizing means including at least one pair of neutralizing transformers being connected in a wye with a delta paired configuration to receive the first set-pair of pole voltages from the bridge inverter means for primary windings, and said second neutralizing means including a second set-pair of neutralizing transformers being connected in a truncated delta with a truncated delta paired configuration to receive the second set-pair of pole voltages from the bridge inverter means; each phase pole voltage in a set-pair being phase rotated or displaced 120 degrees in a periodic cycle, each pole voltage of each half of a set-pair being further phase displaced a first predetermined amount of phase displacement with respect to the other half of each set-pair of pole voltages for the individual phases of respective circuits in said bridge inverter means, and each phase pole voltage of the second set pair being phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole output phase voltages of an individual first set-pair, said first and second neutralizing means eliminating the low-order harmonic component content so that only those harmonic voltage components of a frequency immediately next adjacent to whole number multiples of twenty-four times fundamental frequency remain, while odd number harmonics of less than twenty-three times the fundamental frequency are cancelled. thereby to reduce and eliminate the low-order harmonic component content of output voltage of inverter circuit while preserving fundamental component output voltage waveform.

Claim 13

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controlled independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, said connecting of said first and second neutralizing means eliminating the low-order harmonic components so that only those harmonic voltage components of a frequency immediately next adjacent to whole number multiples of twenty-four times the fundamental frequency remain, while odd number harmonics of less than twenty-three times the fundamental frequency are cancelled; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases, so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, said connecting the first neutralizing means includes connecting at least one pair of neutralizing transformers in a wye with a delta paired configuration to receive the first set-pair of pole voltages from the bridge inverter output means for primary windings, and connecting said second neutralizing means includes connecting a second set-pair of neutralizing transformers in a truncated delta with a truncated delta paired configuration to receive the second set-pair of pole voltages from the bridge inverter output, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.

Claim 14

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controlled independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, said connecting of said first and second neutralizing means eliminating the low-order harmonic components so that only those harmonic voltage components of a frequency immediately next adjacent to whole number multiples of twenty-four times the fundamental frequency remain, while odd number harmonics of less than twenty-three times the fundamental frequency are cancelled; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases, so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, said connecting the first neutralizing means includes connecting at least one pair of neutralizing transformers in a wye with a delta paired configuration to receive the first set-pair of pole voltages from the bridge inverter output means for primary windings, and connecting said second neutralizing means includes connecting a second set-pair of neutralizing transformers in a truncated delta with a truncated delta paired configuration to receive the second set-pair of pole voltages from the bridge inverter output, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.

Claim 17

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controlled independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, the connecting of the first neutralizing means includes connecting at least one pair of neutralizing transformers in a wye with a delta paired configuration to receive the first set-pair of pole voltages from the bridge inverter output means for primary windings, and connecting said second neutralizing means includes connecting a second set-pair of neutralizing transformers in a delta with a delta paired configuration, so that connecting the delta paired transformer winding configuration connects a transformer interphase winding serially with a main transformer winding of a different or shifted phase; and operating delta paired transformer configuration as a truncated type of arrangement such as two truncated delta transformers connected in an opposing pair configuration in order to receive the second set-pair of pole voltages from the bridge inverter output; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases, so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.

Claim 18

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controlled independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, the connecting of the first neutralizing means includes connecting at least one pair of neutralizing transformers in a wye with a delta paired configuration to receive the first set-pair of pole voltages from the bridge inverter output means for primary windings, and connecting said second neutralizing means includes connecting a second set-pair of neutralizing transformers in a delta with a delta paired configuration, so that connecting the delta paired transformer winding configuration connects a transformer interphase winding serially with a main transformer winding of a different or shifted phase; and operating delta paired transformer configuration as a truncated type of arrangement such as two truncated delta transformers connected in an opposing pair configuration in order to receive the second set-pair of pole voltages from the bridge inverter output; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases, so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.

Claim 19

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controller independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, the step of connecting separate sets of phase displaced three-phase pole voltages to respective neutralizing means providing the phase displacement between each respective phase of related phase in an ABC rotation with one and other of both set-pairs being 30 degrees; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases; so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, the straddling of the phase displacement between the related phases of the first set-pair being 15 degrees with respect to the second set-pair; and, the step of providing the pole voltages being adapted for switchably controlling by strategic notching for reducing the output pole voltage therefrom, within the range of a zoned or positioned half-wave time controlled interval notch, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.

Claim 20

A method of operating a twelve-pole inverter apparatus for a three-phase inverter system which provides a fundamental output voltage adapted to be controller independently of a source of DC input voltage, said method comprising: providing four separate sets of constantly phase displaced pole voltages in two set-pairs from bridge inverter output constituted by first and second set-pairs of three-phase pole voltages; connecting first neutralizing means to receive the pole voltages from the first set-pair and connecting second neutralizing means to receive the pole voltages from the second set-pair, the step of connecting separate sets of phase displaced three-phase pole voltages to respective neutralizing means providing the phase displacement between each respective phase of related phase in an ABC rotation with one and other of both set-pairs being 30 degrees; additionally rotating each phase pole voltage in a set-pair, after already being phase rotated or displaced 120 degrees in a periodic cycle, so that each pole voltage of each half of a set-pair is further phase displaced a first predetermined amount of phase displacement with respect to other half of each set-pair of pole voltages for individual phases; so that each phase pole voltage of the second set-pair is phase displaced one-half the first predetermined amount of phase displacement to straddle respective pole phase voltages of the individual first set-pair, the straddling of the phase displacement between the related phases of the first set-pair being 15 degrees with respect to the second set-pair; and, the step of providing the pole voltages being adapted for switchably controlling by strategic notching for reducing the output pole voltage therefrom, within the range of a zoned or positioned half-wave time controlled interval notch, thereby reducing and eliminating low-order harmonic component content, below twenty-three times fundamental frequency of the output voltage of inverter circuit, while preserving fundamental component output voltage waveform.