Power regeneration system for chopper circuits

Claim 2

A power regeneration system for chopper circuits comprising at least one main thyristor with its anode being disposed on the positive side of a direct-current voltage, a first commutation reactor forming a first series circuit with at least one main thyristor, a first auxiliary thyristor with its anode being disposed on the positive side of said direct current voltage, a second commutation reactor forming a second series circuit with said first auxiliary thyristor, one end of each of said first and second series circuits being connected to the positive side of said direct-current voltage, a first commutation diode connected in parallel with said at least one main thyristor in such a manner that their polarity is reversed, at least one commutation capacitor connected between the other ends of said first and second series circuits, a second commutation diode with its anode being disposed on the negative side of said direct current voltage, at least one power regeneration thyristor connected to said second commutation diode to form a parallel circuit therewith in such a manner that their polarity is reversed, a third commutation reactor disposed between the negative side of said direct-current voltage and said parallel circuit which is also connected to one end of said at least one commutation capacitor on the main thyristor side, a second auxiliary thyristor with its cathode end being connected to the negative side of said direct-current voltage and its anode end being connected to the juncture of said at least one commutation capacitor and the cathode end of said first auxiliary thyristor, a fourth commutation reactor connected between the cathode of said second auxiliary thyristor and the negative side of said direct-current voltage and forming a third series circuit with said second auxiliary thyristor, said third series circuit being connected between said at least one commutation capacitor and the negative side of said direct-current voltage.

Claim 3

In a chopper circuit for supplying a variable amount of power from a direct current source to a load, said chopper circuit including a main switching device for supplying a controllable amount of power from said source to said load; a first auxiliary switching device connected across said main switching device to aid the switching thereof; a first commutation reactor; a commutation capacitor connected to said main and said first auxiliary switching devices; and a commutation diode connected across said main switching device, said first commutation reactor and said commutation capacitor forming a first portion of a first resonant circuit across said main switching device to switch said main switching device; a direct-current reactor serially connected with said load; a smoothing diode connected across said load and said direct-current reactor; and switching means for reversing the terminals of said smoothing diode to return power stored in said direct-current reactor to said source when said main switching device is nonconducting, the improvement which comprises: a second auxiliary switching device connected between said first auxiliary switching device and said direct current source to discharge said commutation capacitor when both said main and said first auxiliary switching devices are nonconducting.

Claim 4

In a chopper circuit for supplying a variable amount of power from a direct current source to a load, said chopper circuit including a main switching device for supplying a controllable amount of power from said source to said load; a first auxiliary switching device connected across said main switching device to aid the switching thereof; a first commutation reactor; a commutation capacitor connected to said main and said first auxiliary switching devices; and a commutation diode connected across said main switching device, said first commutation reactor and said commutation capacitor forming a first portion of a first resonant circuit across said main switching device to switch said main switching device; a direct-current reactor serially connected with said load; a smoothing diode connected across said load and said direct-current reactor; and switching means for reversing the terminals of said smoothing diode to return power stored in said direct-current reactor to said source when said main switching device is nonconducting, the improvement which comprises: a second auxiliary switching device connected between said first auxiliary switching device and said direct current source to discharge said commutation capacitor when both said main and said first auxiliary switching devices are nonconducting.

Claim 5

The chopper circuit according to claim 2, wherein said first commutation reactor is serially connected with said main switching device, and said switching means comprises a. a second commutation reactor serially connected with said first auxiliary switching device and forming a second portion of said first resonant circuit with said commutation capacitor across said main switching device; and b. a third commutation reactor serially connected with a power return device and forming a first portion of a second resonant circuit with said commutation capacitor across said load and said direct-current reactor, said second portion of the first resonant circuit effecting, with said first portion of the first resonant circuit, switching of said main device, and said second resonant circuit effecting switching of said second auxiliary switching device.

Claim 6

The chopper circuit according to claim 3 further comprising a fourth commutation reactor serially connected with said second auxiliary switching device and forming a second portion of said second resonant circuit across said main switching device, said first and second portions of said second resonant circuit together effecting switching of said second auxiliary device.

Claim 7

A chopper circuit for supplying a variable amount of power from a direct-current source to a load, which comprises: a. a main switching device connected between said direct current source and said load to supply said power; b. an oppositely poled first commutation diode connected in parallel across said main device to aid the switching thereof; c. a first commutation reactor serially connected with the parallel connection of said main device and said first commutation diode; d. a direct-current reactor serially connected to said load to store energy when said main switching device is nonconducting; e. a commutation capacitor connected at one end of the juncture of said main switching device and said direct-current reactor and forming with said first commutation reactor a first portion of a resonant circuit to switch said main device; f. a first auxiliary switching device serially connected with a second commutation reactor between the other end of said commutation capacitor and said source, said second commutation reactor forming with said commutation capacitor a second portion of said resonant circuit to switch said main device; g. a power return device connected in parallel across said direct-current reactor and said load; h. an oppositely poled second commutation diode connected in parallel with said power return device to provide a discharge path for said commutation capacitor; i. a third commutation reactor serially connected with said power return device and forming a first portion of a second resonant circuit with said commutation capacitor; k. a second auxiliary switching device connected between the juncture of said commutation capacitor and said first auxiliary switching device and said source to provide a charging path for said commutation capacitor; and l. a fourth commutation reactor serially connected with said second auxiliary switching device and forming a second portion of said second resonant circuit with said commutation capacitor, said first and second portions of said second resonant circuit cooperating to effect switching of said second auxiliary switching device.

Claim 8

A chopper circuit for supplying a variable amount of power from a direct-current source to a load, which comprises: a. a main switching device connected between said direct current source and said load to supply said power; b. an oppositely poled first commutation diode connected in parallel across said main device to aid the switching thereof; c. a first commutation reactor serially connected with the parallel connection of said main device and said first commutation diode; d. a direct-current reactor serially connected to said load to store energy when said main switching device is nonconducting; e. a commutation capacitor connected at one end of the juncture of said main switching device and said direct-current reactor and forming with said first commutation reactor a first portion of a resonant circuit to switch said main device; f. a first auxiliary switching device serially connected with a second commutation reactor between the other end of said commutation capacitor and said source, said second commutation reactor forming with said commutation capacitor a second portion of said resonant circuit to switch said main device; g. a power return device connected in parallel across said direct-current reactor and said load; h. an oppositely poled second commutation diode connected in parallel with said power return device to provide a discharge path for said commutation capacitor; i. a third commutation reactor serially connected with said power return device and forming a first portion of a second resonant circuit with said commutation capacitor; k. a second auxiliary switching device connected between the juncture of said commutation capacitor and said first auxiliary switching device and said source to provide a charging path for said commutation capacitor; and l. a fourth commutation reactor serially connected with said second auxiliary switching device and forming a second portion of said second resonant circuit with said commutation capacitor, said first and second portions of said second resonant circuit cooperating to effect switching of said second auxiliary switching device.