Firing signal transmission control means for inverter circuits

Claim 2

In an inverter circuit including at least one set of two series connected load current carrying gate controlled rectifiers connected across a source of direct current electric power, a respective set of two series connected commutating gate controlled rectifiers of similar polarity connected across said source of electric power, a capacitor and an inductor connected in series circuit relationship between the junction of said two load rectifiers and the junction of said two commutating rectifiers, a set of two diode rectifiers each connected in parallel circuit relationship across a respective one of said load rectifiers in reverse polarity with respect to said load rectifier, and firing signal generation means for generating firing signals for delivery in a predetermined cyclic sequence to said rectifiers, firing signal transmission control means comprising: first firing signal transmission means between said signal generation means and said commutating rectifiers, said first firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented, second firing signal transmission means between said signal generation means and said load rectifiers, said second firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented, control signal generation means for generating an operate signal when operation of the inverter circuit is desired and a nonoperate signal when operation of the inverter circuit is not desired, first enabling means coupled to said control signal generation means and said first firing signal transmission means and being responsive to an operate signal to maintain said first firing signal transmission means in its said first operative condition throughout the entire duration of the operate signal, and second enabling means coupled to said control signal generation means, said second firing signal transmission means, and said firing signal generation means and being responsive to an operate signal and the first firing signal to one of said commutating rectifiers following the initiation of the operate signal to maintain said second firing signal transmission means in its said first operation condition throughout the remaining duration of the operate signal, whereby operation of the inverter circuit is initiated by the firing of one of the commutating rectifiers.

Claim 3

Firing signal transmission control means as defined by claim 1 in which said second enabling means is responsive to a non-operate signal to maintain said second firing signal transmission means in its said second operative condition throughout the entire duration of the non-operate signal.

Claim 4

Firing signal transmission control means as defined by claim 2 in which said first enabling means further comprises means for detecting the firing of said commutating rectifiers, said first enabling means being responsive to a non-operate signal and the firing of one of said commutating rectifiers following the initiation of the non-operate signal to maintain said first firing signal transmission means in its said second operative condition throughout the remaining duration of the non-operate signal, whereby operation of the inverter circuit ceases with the firing of a commutating rectifier.

Claim 5

Firing signal transmission control means as defined by claim 3 in which said first enabling means is responsive to a non-operate signal and the first firing of a commutating rectifier following the initiation of the non-operate signal.

Claim 6

Firing signal transmission control means as defined by claim 3 in which said first enabling means and said second enabling means comprise logic networks.

Claim 7

Firing signal transmission control means as defined by claim 1 in which said control signal generation means includes an output coupled to said first and second enabling means, a primary input, and at least one second secondary input, said control signal generation means adapted to initially generate a selected one of the operate and non-operate signals at said output only in response to the combination of a predetermined signal at said primary input and a predetermined signal at said secondary input and thereafter maintain the selected signal at said output so long as the predetermined signal is maintained at said primary input.

Claim 8

Firing signal transmission control means as defined by claim 6 in which said control signal generation means comprises a logic network having said primary and secondary inputs and said output.

Claim 9

Firing signal transmission control means as defined by claim 7 in which said lock network includes feedback latching means coupled to said secondary input.

Claim 10

Firing signal transmission control means as defined by claim 1 in which said control signal generation means includes an output coupled to said first and second enabling means, at least one primary input, at least one secondary input, and logic means interconnecting said inputs and said output, said logic means adapted to initially generate an operate signal at said output only in response to a combination of start signals at all of said primary inputs and a signal representative of a predetermined operating condition at at least one of said secondary inputs and thereafter maintain the operate signal at said output so long as start signals are maintained at all of said primary inputs.

Claim 11

Firing signal transmission control means as defined by claim 9 in which said logic means includes at least first and second primary inputs, said logic means adapted to immediately generate a non-operate signal at said output in response to a stop signal at said first primary input irrespective of the signals at said second primary input and said secondary input.

Claim 12

Firing signal transmission control means as defined by claim 10 in which said logic means is adapted to generate a non-operate signal at said output in response to a combination of a start signal at said first primary input and a stop signal at said second primary input only when a signal representative of a predetermined operating condition is supplied to at least one of said secondary inputs, said logic means thereafter maintaining the non-operate signal so long as the stop signal is maintained at said second primary input.

Claim 13

Firing signal transmission control means as defined by claim 11 in which said second enabling means is responsive to a non-operate signal to maintain said second firing signal transmission means in its second operate condition throughout the entire duration of the non-operate signal.

Claim 14

Firing signal transmission control means as defined by claim 12 in which said first enabling means further comprises means for detecting the firing of said commutating rectifiers, said first enabling means being responsive to a non-operate signal and the firing of one of said commutating rectifiers following the initiation of the non-operate signal to maintain said first firing signal transmission means in its said second operative condition throughout the remaining duration of the non-operate signal, whereby operation of the inverter circuit ceases with the firing of commutation rectifier.

Claim 15

Firing signal transmission conTrol means as defined by claim 13 in which said first enabling means is responsive to a non-operate signal and the first firing a commutating rectifier following the initiation of the non-operate signal.

Claim 16

Firing signal transmission control means as defined by claim 13 in which said first enabling means and said second enabling means comprise logic networks.

Claim 17

An a-c adjustable speed drive system comprising: a polyphase a-c motor; static power conversion means for changing direct current electric power to variable frequency polyphase electric power, said conversion means comprising a plurality of inverter circuits each adapted to couple a source of d-c electric power and a respective phase of said motor, each of said inverter circuits comprising at least one set of two series connected load current carrying gate controlled rectifiers for connection across the d-c source, a respective set of two series connected commutating gate controlled rectifiers of similar polarity for connection across the d-c source, a capacitor and an inductor connected in series circuit relationship between the junction of said two load rectifiers and the junction of said two commutating rectifiers, and a set of two diode rectifiers each connected in parallel circuit relationship across a respective one of said load rectifiers in reverse polarity with respect to said load rectifier; firing signal generation means for generating firing signals for delivery to the rectifiers of all of said inverter circuits, the firing signals for delivery to the rectifiers of any selected inverter circuit being generated in a predetermined cyclic sequence and at the same frequency as the firing signals for delivery to the other inverter circuits; control signal generation means for generating an operate signal when operation of said motor is desired and a non-operate signal when operation of said motor is not desired; a plurality of first firing signal transmission means each between said firing signal generation means and the commutating rectifiers of a respective one of said inverter circuits, each of said first firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented; a plurality of second firing signal transmission means each between said firing signal generation means and the load rectifiers of a respective one of said inverter circuits, each of said second firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented; a plurality of first enabling means each coupled to said control signal generation means and a respective one of said first firing signal transmission means and being responsive to an operate signal to maintain said respective first firing signal transmission means in its said first operative condition throughout the duration of the operate signal; a plurality of second enabling means each coupled to said control signal generation means, a respective one of said second firing signal transmission means, and said firing signal generation means and being responsive to an operate signal and the first firing signal to one of the commutating rectifiers of the respective inverter circuit following the initiation of the operate signal to maintain said respective second firing signal transmission means in its said first operative condition throughout the remaining duration of the operate signal; whereby operation of the drive system is initiated in each of said inverter circuits by the firing of one of the commutating rectifiers.

Claim 18

An a-c adjustable speed drive system comprising: a polyphase a-c motor; static power conversion means for changing direct current electric power to variable frequency polyphase electric power, said conversion means comprising a plurality of inverter circuits each adapted to couple a source of d-c electric power and a respective phase of said motor, each of said inverter circuits comprising at least one set of two series connected load current carrying gate controlled rectifiers for connection across the d-c source, a respective set of two series connected commutating gate controlled rectifiers of similar polarity for connection across the d-c source, a capacitor and an inductor connected in series circuit relationship between the junction of said two load rectifiers and the junction of said two commutating rectifiers, and a set of two diode rectifiers each connected in parallel circuit relationship across a respective one of said load rectifiers in reverse polarity with respect to said load rectifier; firing signal generation means for generating firing signals for delivery to the rectifiers of all of said inverter circuits, the firing signals for delivery to the rectifiers of any selected inverter circuit being generated in a predetermined cyclic sequence and at the same frequency as the firing signals for delivery to the other inverter circuits; control signal generation means for generating an operate signal when operation of said motor is desired and a non-operate signal when operation of said motor is not desired; a plurality of first firing signal transmission means each between said firing signal generation means and the commutating rectifiers of a respective one of said inverter circuits, each of said first firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented; a plurality of second firing signal transmission means each between said firing signal generation means and the load rectifiers of a respective one of said inverter circuits, each of said second firing signal transmission means having a first operative condition in which transmission therethrough of firing signals is permitted and a second operative condition in which transmission therethrough of firing signals is prevented; a plurality of first enabling means each coupled to said control signal generation means and a respective one of said first firing signal transmission means and being responsive to an operate signal to maintain said respective first firing signal transmission means in its said first operative condition throughout the duration of the operate signal; a plurality of second enabling means each coupled to said control signal generation means, a respective one of said second firing signal transmission means, and said firing signal generation means and being responsive to an operate signal and the first firing signal to one of the commutating rectifiers of the respective inverter circuit following the initiation of the operate signal to maintain said respective second firing signal transmission means in its said first operative condition throughout the remaining duration of the operate signal; whereby operation of the drive system is initiated in each of said inverter circuits by the firing of one of the commutating rectifiers.

Claim 19

A drive system as defined by claim 16 in which each of said second enabling means is responsive to a non-operate signal to maintain said respective second firing signal transmissiOn means in its said second operative condition throughout the entire duration of the non-operate signal, and in which each of said first enabling means further comprises means for detecting the firing of said commutating rectifiers of the respective inverter circuit and in which each of said first enabling means is responsive to a non-operate signal and the firing of one of said commutating rectifiers of the respective inverter circuit following the initiation of the non-operate signal to maintain said respective first firing signal transmission means in its said second operative condition throughout the remaining duration of the non-operate signal, whereby operation of the drive system ceases in each of said inverter circuits by the firing of a commutating rectifier.

Claim 20

A drive system as defined by claim 16 in which said control signal generation means includes an output coupled to all of said first and second enabling means, a primary input, and at least one secondary input, said control signal generation means adapted to initially generate a selected one of the operate and non-operate signals at said output only in response to the combination of a predetermined signal at said primary input and a predetermined signal at said secondary input and thereafter maintain the selected signal at said output so long as the predetermined signal is maintained at said primary input.