Apparatus for repeatedly applying short-circuit pulses to a current type inverter for output current control

Claim 1

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; pulse width modulation pattern generation circuit means for generating, in synchronism with said clock signal, pulse width modulation pattern signals for respective ones of said self-extinguish elements; short-circuit pulse generating circuit means for generating, in synchronism with said clock signal, short-circuit pulses having a predetermined pulse width for turning on ones of said self-extinguish elements connected in series with others of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by the corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC of said inverter; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.

Claim 2

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; pulse width modulation pattern generation circuit means for generating, in synchronism with said clock signal, pulse width modulation pattern signals for respective ones of said self-extinguish elements; short-circuit pulse generating circuit means for generating, in synchronism with said clock signal, short-circuit pulses having a predetermined pulse width for turning on ones of said self-extinguish elements connected in series with others of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by the corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC of said inverter; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.

Claim 6

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; pulse width modulation pattern generation circuit means for generating, in synchronism with said clock signal, pulse width modulation pattern signals for respective ones of said self-extinguish elements of said bridge circuit; frequency dividing circuit means for generating a pulse train signal having a predetermined pulse width in synchronism with a frequency divided signal obtained by frequency dividing said clock signal; short-circuit pulse generating circuit means for ANDing said pulse train signal and portions of said pulse width modulation pattern signals having a phase of 0 to 1/3π and a phase 2/3π to π, and for generating short-circuit pulse signals for turning on ones of said self-extinguish elements connected in series with others of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by the corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC circuit of said inverter; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.

Claim 7

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; pulse width modulation pattern generation circuit means for generating, in synchronism with said clock signal, pulse width modulation pattern signals for respective ones of said self-extinguish elements of said bridge circuit; frequency dividing circuit means for generating a pulse train signal having a predetermined pulse width in synchronism with a frequency divided signal obtained by frequency dividing said clock signal; short-circuit pulse generating circuit means for ANDing said pulse train signal and portions of said pulse width modulation pattern signals having a phase of 0 to 1/3π and a phase 2/3π to π, and for generating short-circuit pulse signals for turning on ones of said self-extinguish elements connected in series with others of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by the corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC circuit of said inverter; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.

Claim 9

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; reference pattern signal generating circuit means for generating, in synchronism with said clock signal, a reference pattern signal having a phase of 0 to 1/3π of pulse width modulation pattern signals and being synchronous with respect to 1/6π thereof; non-uniform-period triangular waveform signal generator means for generating a non-uniform-period triangular waveform signal corresponding to said reference pattern signal in synchronism with said clock signal; short-circuit pulse generating circuit means for comparing said non-uniform-period triangular waveform signal with a command value of an output current of said inverter, and for generating short-circuit pulse signals for turning on ones of said self-extinguish elements connected in series with other of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC circuit of said inverter; pulse width modulation pattern signal generating circuit means for generating pulse width modulation pattern signals for said self-extinguish elements of said bridge circuit in accordance with said reference pattern signal and said short-circuit pulse signals; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.

Claim 10

An apparatus for controlling a current type inverter including a bridge circuit of bridge-connected self-extinguish elements triggered by pulse width modulation signals, said apparatus comprising: clock generator means for generating a clock signal in accordance with a frequency command; reference pattern signal generating circuit means for generating, in synchronism with said clock signal, a reference pattern signal having a phase of 0 to 1/3π of pulse width modulation pattern signals and being synchronous with respect to 1/6π thereof; non-uniform-period triangular waveform signal generator means for generating a non-uniform-period triangular waveform signal corresponding to said reference pattern signal in synchronism with said clock signal; short-circuit pulse generating circuit means for comparing said non-uniform-period triangular waveform signal with a command value of an output current of said inverter, and for generating short-circuit pulse signals for turning on ones of said self-extinguish elements connected in series with other of said self-extinguish elements to form pairs in said bridge circuit, the others of said self-extinguish elements being turned on by corresponding pulse width modulation pattern signals, thereby enabling short-circuiting of a DC circuit of said inverter; pulse width modulation pattern signal generating circuit means for generating pulse width modulation pattern signals for said self-extinguish elements of said bridge circuit in accordance with said reference pattern signal and said short-circuit pulse signals; composite circuit means for generating trigger pattern signals for triggering said self-extinguish elements of said bridge circuit in accordance with said pulse width modulation pattern signals and said short-circuit pulse signals; and driver circuit means for delivering trigger signals to said self-extinguish elements of said bridge circuit in accordance with said trigger pattern signals.