Regenerative braking circuit

Claim 2

A power conversion circuit for connection across a d-c power source comprising: a. power conversion means having input terminals for connection to said d-c power source and output terminals for connection to a load; b. commutation means connected to said power conversion means to commutate the current between said input and said output terminals, said commutation means having an increased commutation ability with increased voltage across said input terminals; c. a dynamo electric machine for connection across said output terminals, said machine being capable of separately performing motoring and generating functions, so as to receive power from said power conversion means during periods of motoring and deliver power thereto during periods of generation; d. means for increasing the voltage across said input terminals above that which exists at said power source during periods of generation, thereby allowing said commutation means to commutate a greater amount of power during generation than during motoring.

Claim 3

A power conversion circuit as set forth in claim 1 wherein said voltage increasing means comprises an impedance selectively connectable in series between said power source and said input terminals.

Claim 4

A power conversion circuit as set forth in claim 2 wherein said voltage increasing means further includes a diode connected across said impedance to conduct current during periods of motoring.

Claim 5

A power conversion circuit as set forth in claim 1 wherein said power conversion means is an inverter for converting d-c current at the input terminals to a-c current at the output terminals and further wherein said dynamo-electric machine comprises an a-c induction motor.

Claim 6

A power conversion circuit as set forth in claim 4 wherein said inverter is an impulse commutated inverter.

Claim 7

A power conversion circuit as set forth in claim 4 wherein said commutation means includes a capacitor selectively connectable across at least one controlled rectifier of said inverter.

Claim 8

A power conversion circuit as set forth in claim 6 wherein said commutation means further includes an inductance serially connected with said capacitor to provide an oscillatory network.

Claim 9

A power control circuit for an inverter having input terminals connected to a d-c source and having output terminals connected to an a-c motor comprising: a. a d-c power source for delivering d-c power to the input terminals during periods of motoring and receiving d-c power therefrom during periods of generation; b. commutation means connected to the inverter to commutate the current between the input and output terminals, said commutation means having an increased commutation ability with increased voltage across said input terminals; c. an a-c motor connected to the inverter output terminals for receiving power therefrom during selected periods of motoring and delivering power thereto during selected periods of generation; d. means for increasing the voltage across said input terminals, above that of said d-c power source, during periods of generation, thereby increasing the commutation ability of said commutation means during said periods of generation.

Claim 10

A power control circuit for an inverter having input terminals connected to a d-c source and having output terminals connected to an a-c motor comprising: a. a d-c power source for delivering d-c power to the input terminals during periods of motoring and receiving d-c power therefrom during periods of generation; b. commutation means connected to the inverter to commutate the current between the input and output terminals, said commutation means having an increased commutation ability with increased voltage across said input terminals; c. an a-c motor connected to the inverter output terminals for receiving power therefrom during selected periods of motoring and delivering power thereto during selected periods of generation; d. means for increasing the voltage across said input terminals, above that of said d-c power source, during periods of generation, thereby increasing the commutation ability of said commutation means during said periods of generation.

Claim 11

A power coNtrol circuit as set forth in claim 8 wherein said voltage increasing means comprises an impedance selectively connected in series between said power source and said input terminals.

Claim 12

A power control circuit as set forth in claim 9 wherein said voltage increasing means further includes a diode across said impedance to conduct current during periods of motoring.

Claim 13

A power control circuit as set forth in claim 8 wherein said commutation means includes a capacitor selectively connectable across at least one controlled rectifier of said inverter.

Claim 14

A power control circuit as set forth in claim 11 wherein said commutation means further includes an inductance serially connected to said capacitor to provide an oscillatory network.

Claim 15

A power conversion circuit for connection across d-c power source comprising: a. power conversion means having input terminals for connection across said d-c power source and output terminals for connection to a load; b. commutation means connected to said power conversion means to commutate the current between said input and said output terminals, said commutation means having an increased commutation ability with increased voltage across said input terminals; c. a dynamo-electric machine for connection aid output terminals, said dynamic machine being capable of separately performing motoring and generating functions so as to respectively receive power from and deliver power to said power conversion means during those periods of operation; d. a resistor connectable in series between said d-c power source and said power conversion input terminals to increase the voltage across said input terminals above that across said d-c power source; and e. means for effectively switching said resistor into the circuit during periods of generation and switching said resistor out of the circuit during periods of motoring.

Claim 16

A power conversion circuit for connection across d-c power source comprising: a. power conversion means having input terminals for connection across said d-c power source and output terminals for connection to a load; b. commutation means connected to said power conversion means to commutate the current between said input and said output terminals, said commutation means having an increased commutation ability with increased voltage across said input terminals; c. a dynamo-electric machine for connection aid output terminals, said dynamic machine being capable of separately performing motoring and generating functions so as to respectively receive power from and deliver power to said power conversion means during those periods of operation; d. a resistor connectable in series between said d-c power source and said power conversion input terminals to increase the voltage across said input terminals above that across said d-c power source; and e. means for effectively switching said resistor into the circuit during periods of generation and switching said resistor out of the circuit during periods of motoring.

Claim 17

A power conversion circuit as set forth in claim 13 wherein said switching means comprises a diode connected across said resistor.

Claim 18

A power conversion circuit as set forth in claim 14 wherein during periods of generation a portion of the power generated thereby is returned to said d-c power source.