Electronic switching for the windings of electrical machinery

Claim 1

A system for switching and chopping DC current flowing through the windings of an electric machine comprising: a direct current voltage source; a pair of power supply conductors connected to the opposite ends of said DC source; a plurality of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between respectively the first power supply conductor and, through a freewheeling diode oriented as the freewheeling thyristor, the second power supply conductor, the junction between thyristors of each pair being connected with one end of each winding; a common junction between the others ends of the windings; a smoothing reactor common to the various windings and connected between the said common junction and the second power supply conductor; a shutoff capacitor connected in series with an inductance to form an oscillatory circuit connected at one terminal to the second power supply conductor; an auxiliary thyristor; and means including said oscillatory circuit and said auxiliary thyristor for electrically connecting the first supply conductor to the other terminal of the oscillatory circuit whose shutoff capacitor is consequently energizable by the DC source and for discharging such shutoff capacitor around the anode-cathode of the supply thyristors and for consequently shutting off the supply thyristor which was previously fired, the current in the corresponding winding flowing then, without modification of direction, in a freewheeling conductor path including said winding, said smoothing reactor, said freewheeling diode and the freewheeling thyristor connected in opposite direction with said supply thyristor.

Claim 2

A system for switching and chopping DC current flowing through the windings of an electric machine comprising: a direct current voltage source; a pair of power supply conductors connected to the opposite ends of said DC source; a plurality of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between respectively the first power supply conductor and, through a freewheeling diode oriented as the freewheeling thyristor, the second power supply conductor, the junction between thyristors of each pair being connected with one end of each winding; a common junction between the others ends of the windings; a smoothing reactor common to the various windings and connected between the said common junction and the second power supply conductor; a shutoff capacitor connected in series with an inductance to form an oscillatory circuit connected at one terminal to the second power supply conductor; an auxiliary thyristor; and means including said oscillatory circuit and said auxiliary thyristor for electrically connecting the first supply conductor to the other terminal of the oscillatory circuit whose shutoff capacitor is consequently energizable by the DC source and for discharging such shutoff capacitor around the anode-cathode of the supply thyristors and for consequently shutting off the supply thyristor which was previously fired, the current in the corresponding winding flowing then, without modification of direction, in a freewheeling conductor path including said winding, said smoothing reactor, said freewheeling diode and the freewheeling thyristor connected in opposite direction with said supply thyristor.

Claim 3

A system for switching and chopping DC current flowing through the windings of an electric machine comprising: a source of direct current; a pair of power supply conductors connected across the opposite ends of said DC source; a plurality of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between respectively the first power supply conductor and, through one freewheeling diode oriented as the freewheeling thyristors, the second power supply conductor, the junction between thyristors of each pair being connected to one end of each winding; a common junction between the other ends of the windings; a smoothing reactor common to the various windings connected between the said common junction and the second supply conductor; a shutoff capacitor connected in series with an inductance to form an oscillatory circuit, one of the terminals of said capacitor being directly connected to the second power supply conductor; a plurality of diodes having common electrodes connected to the inductance of the oscillatory circuit and their other electrodes to junctions between freewheeling and supply thyristors, these diodes being oriented in such a way that the second terminal of the shutoff capacitor is charged to a potential higher than the one of the first power supply conductor when one supply thyristor is switched to a forward conducting state; an auxiliary thyristor connected between the junction capacitor-inductance of the oscillatory circuit and the common junction of the freewheeling thyristors so that the fired supply thyristor is shutoff by the potential of the second terminal when the said auxiliary thyristor and the freewheeling thyristor associated with the said supply thyristor are switched to a forward conducting state and so that the currEnt in the winding consequently flow, without modification of direction in a freewheeling conducting path including said winding, said smoothing reactor, said freewheeling diode and the said freewheeling thyristor; and a diode and an inductance connected in series between the first power conductor and the common junction of the freewheeling thyristors for equalizing the potentials of the two terminals of the shutoff capacitor when the auxiliary thyristor is switched to a forward conducting state.

Claim 4

A system for switching and chopping DC current flowing through the windings of an electric machine comprising: a source of direct current; a pair of power supply conductors connected across the opposite ends of said DC source; a plurality of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between respectively the first power supply conductor and, through one freewheeling diode oriented as the freewheeling thyristors, the second power supply conductor, the junction between thyristors of each pair being connected to one end of each winding; a common junction between the other ends of the windings; a smoothing reactor common to the various windings connected between the said common junction and the second supply conductor; a shutoff capacitor connected in series with an inductance to form an oscillatory circuit, one of the terminals of said capacitor being directly connected to the second power supply conductor; a plurality of diodes having common electrodes connected to the inductance of the oscillatory circuit and their other electrodes to junctions between freewheeling and supply thyristors, these diodes being oriented in such a way that the second terminal of the shutoff capacitor is charged to a potential higher than the one of the first power supply conductor when one supply thyristor is switched to a forward conducting state; an auxiliary thyristor connected between the junction capacitor-inductance of the oscillatory circuit and the common junction of the freewheeling thyristors so that the fired supply thyristor is shutoff by the potential of the second terminal when the said auxiliary thyristor and the freewheeling thyristor associated with the said supply thyristor are switched to a forward conducting state and so that the currEnt in the winding consequently flow, without modification of direction in a freewheeling conducting path including said winding, said smoothing reactor, said freewheeling diode and the said freewheeling thyristor; and a diode and an inductance connected in series between the first power conductor and the common junction of the freewheeling thyristors for equalizing the potentials of the two terminals of the shutoff capacitor when the auxiliary thyristor is switched to a forward conducting state.

Claim 7

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the first power supply conductor and, through one first freewheeling diode, the second power supply conductor, the junction between the thyristors of each pair being connected with one end of each winding of the first winding group; a second group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the second supply conductor and, through one second freewheeling diode, the first power supply conductor, the junction between thyristors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of the windings of the first group and a common junction between the second ends of the windings of the second group; a smoothing reactor connected between these two common junctions; a first and a second oscillatory circuits comprising each an inductance and a shutoff capacitor; electronics means including the first oscillatory circuit to supply with said DC source said first oscillatory circuit when a supply thyristor of the first group switches to a forward conducting state and consequently to charge the capacitor of said oscillatory circuit with a voltage higher than the one of the source of direct current, and to apply, by turning a freewheeling thyristor associated with said supply thyristor, the higher voltage to the anode-cathode of said supply thyristor so that said thyristor is shut off and that the current in the winding of the first and second group winding flow in a first freewheeling conducting path including said windings, said smoothing reactor, one supply thyristor of the second group, the first freewheeling diode and one freewheeling thyristor of the first group; electronics means including the second oscillatory circuit to supply with said DC source said second oscillatory circuit when a supply thyristor of the second group switches to a forward conducting state and consequently to charge the capacitor of said oscillatory circuit with a voltage higher than the one of the source of direct current, and to apply, by turning on a freewheeling thyristor associated with said supply thyristor, the higher voltage to the anode-cathode of said supply thyristor so that said thyristor is shut off and that the current in the winding of the first group and the second group flow in a second freewheeling conducting path including said windings, said smoothing reactor, one supply thyristor of the first group, the second freewheeling diode, and one freewheeling thyristor of the second group.

Claim 8

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the first power supply conductor and, through one first freewheeling diode, the second power supply conductor, the junction between the thyristors of each pair being connected with one end of each winding of the first winding group; a second group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the second supply conductor and, through one second freewheeling diode, the first power supply conductor, the junction between thyristors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of the windings of the first group and a common junction between the second ends of the windings of the second group; a smoothing reactor connected between these two common junctions; a first and a second oscillatory circuits comprising each an inductance and a shutoff capacitor; electronics means including the first oscillatory circuit to supply with said DC source said first oscillatory circuit when a supply thyristor of the first group switches to a forward conducting state and consequently to charge the capacitor of said oscillatory circuit with a voltage higher than the one of the source of direct current, and to apply, by turning a freewheeling thyristor associated with said supply thyristor, the higher voltage to the anode-cathode of said supply thyristor so that said thyristor is shut off and that the current in the winding of the first and second group winding flow in a first freewheeling conducting path including said windings, said smoothing reactor, one supply thyristor of the second group, the first freewheeling diode and one freewheeling thyristor of the first group; electronics means including the second oscillatory circuit to supply with said DC source said second oscillatory circuit when a supply thyristor of the second group switches to a forward conducting state and consequently to charge the capacitor of said oscillatory circuit with a voltage higher than the one of the source of direct current, and to apply, by turning on a freewheeling thyristor associated with said supply thyristor, the higher voltage to the anode-cathode of said supply thyristor so that said thyristor is shut off and that the current in the winding of the first group and the second group flow in a second freewheeling conducting path including said windings, said smoothing reactor, one supply thyristor of the first group, the second freewheeling diode, and one freewheeling thyristor of the second group.

Claim 9

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the first power supply conductor and, through one first freewheeling diode, the second supply conductor, the junction between the thyristors of each pair being connected to one end of each winding of the first winding group; a second group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the second power supply conductor and, through one second freewheeling diode, the first power supply conductor, the junction between thyristors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of windings of the first group and a common junction between the second ends of windings of the second group; a smoothing reactor connected between these two common junctions; a first shutoff capacitor having one terminal connected to the first supply conductor; a circuit for charging the second terminal of said capacitor to a potential higher than the one of the first supply conductor, when one supply thyristor of the first group is turned on, including an inductance forming a first oscillatory circuit with said capacitor and a first group of diodes connected between said inductance and the junctions between supply and freewheeling thyristors of the first group; a first auxiliary thyristor connected between the junction capacitor-inductance and the common junction of the freewheeling thyristors of the first group, said auxiliary thyristor being oriented so that when it is turned on, together with the freewheeling thyristor associated with the fired supply thyristor of the first group, it applies the high potential of the second terminal of the capacitor to the electrode of said supply thyristor opposite to the one connected to the first supply conductor, said supply thyristor being consequently shut off and the current in the windings of the first and second groups being switched off on a freewheeling conducting path including said smoothing reactor, the first freewheeling diode, the fired supply thyristor of the second group and the fired freewheeling thyristor of the first group; a circuit including a diode and an inductance connected in series and coupled in parallel across the circuit including the first shutoff capacitor and the first auxiliary thyristor, the said inductance forming with the capacitor an oscillatory circuit; a second shutoff capacitor having one terminal connected to the second supply conductor; a circuit for charging the second terminal of said capacitor to a potential higher than the one of the second supply conductor, when one supply thyristor of the second group is turned on, said circuit including an inductance forming a second oscillatory circuit with said capacitor and a second group of diodes connected between said inductance and the junctions between supply and freewheeling thyristors of the second group; a second auxiliary thyristor connected between the junction of said inductance with the second shutoff capacitor and the common junction of the freewheeling thyristors of the second group, the orientation of said second auxiliary thyristor being so that when it is turned on, together with the freewheeling thyristor associated with the fired supply thyristor of the second group, it applies the high potential of the second terminal of the second shutoff capacitor to the electrode of said supply thyristor opposite to the one connected to the second supply conductor, said supply conductor being consequently shut off and the current in the windings of the first and second groups being switched off on a freewheeling conducting path including said smoothing reactor, the second freewheeling diode, the fired supply thyristor of the first group and the fired freewheeling thyristor of the second group; and a circuit including a diode and an inductance connected in series and coupled in parallel across the circuit including the second shutoff capacitor and the second auxiliary thyristor, the said inductance forming with said capacitor an oscillatory circuit.

Claim 10

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the first power supply conductor and, through one first freewheeling diode, the second supply conductor, the junction between the thyristors of each pair being connected to one end of each winding of the first winding group; a second group of pairs of thyristors including a supply thyristor and a freewheeling thyristor series connected in opposite direction between the second power supply conductor and, through one second freewheeling diode, the first power supply conductor, the junction between thyristors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of windings of the first group and a common junction between the second ends of windings of the second group; a smoothing reactor connected between these two common junctions; a first shutoff capacitor having one terminal connected to the first supply conductor; a circuit for charging the second terminal of said capacitor to a potential higher than the one of the first supply conductor, when one supply thyristor of the first group is turned on, including an inductance forming a first oscillatory circuit with said capacitor and a first group of diodes connected between said inductance and the junctions between supply and freewheeling thyristors of the first group; a first auxiliary thyristor connected between the junction capacitor-inductance and the common junction of the freewheeling thyristors of the first group, said auxiliary thyristor being oriented so that when it is turned on, together with the freewheeling thyristor associated with the fired supply thyristor of the first group, it applies the high potential of the second terminal of the capacitor to the electrode of said supply thyristor opposite to the one connected to the first supply conductor, said supply thyristor being consequently shut off and the current in the windings of the first and second groups being switched off on a freewheeling conducting path including said smoothing reactor, the first freewheeling diode, the fired supply thyristor of the second group and the fired freewheeling thyristor of the first group; a circuit including a diode and an inductance connected in series and coupled in parallel across the circuit including the first shutoff capacitor and the first auxiliary thyristor, the said inductance forming with the capacitor an oscillatory circuit; a second shutoff capacitor having one terminal connected to the second supply conductor; a circuit for charging the second terminal of said capacitor to a potential higher than the one of the second supply conductor, when one supply thyristor of the second group is turned on, said circuit including an inductance forming a second oscillatory circuit with said capacitor and a second group of diodes connected between said inductance and the junctions between supply and freewheeling thyristors of the second group; a second auxiliary thyristor connected between the junction of said inductance with the second shutoff capacitor and the common junction of the freewheeling thyristors of the second group, the orientation of said second auxiliary thyristor being so that when it is turned on, together with the freewheeling thyristor associated with the fired supply thyristor of the second group, it applies the high potential of the second terminal of the second shutoff capacitor to the electrode of said supply thyristor opposite to the one connected to the second supply conductor, said supply conductor being consequently shut off and the current in the windings of the first and second groups being switched off on a freewheeling conducting path including said smoothing reactor, the second freewheeling diode, the fired supply thyristor of the first group and the fired freewheeling thyristor of the second group; and a circuit including a diode and an inductance connected in series and coupled in parallel across the circuit including the second shutoff capacitor and the second auxiliary thyristor, the said inductance forming with said capacitor an oscillatory circuit.

Claim 13

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of transistors including a supply transistor and a freewheeling transistor series connected in opposite direction between the first power supply conductor and the second power supply conductor, the junction between the transistors of each pair being connected with one end of each winding of the first winding group; a second group of pairs of transistors including a supply transistor and a freewheeling transistor series connected in opposite direction between the second supply conductor and the first supply conductor, the junction between transistors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of the windings of the first group and a common junction between the second ends of the windings of the second group; and a smoothing reactor connected between said two common junctions.

Claim 14

A system for switching and chopping direct current flowing through the windings of a machine operating by simultaneous energizing of two windings taken one each from two winding groups comprising: a source of direct current; a pair of power supply conductors connected with the opposite ends of said DC source; a first group of pairs of transistors including a supply transistor and a freewheeling transistor series connected in opposite direction between the first power supply conductor and the second power supply conductor, the junction between the transistors of each pair being connected with one end of each winding of the first winding group; a second group of pairs of transistors including a supply transistor and a freewheeling transistor series connected in opposite direction between the second supply conductor and the first supply conductor, the junction between transistors of each pair being connected with one end of each winding of the second winding group; a common junction between the second ends of the windings of the first group and a common junction between the second ends of the windings of the second group; and a smoothing reactor connected between said two common junctions.