Inverter with bidirectional inverter for regenerative current
AssigneeSundstrand Corporation
InventorDavid J. Hucker
Life of this patent
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Abstract
A bidirectional inverter circuit for evenly distributing energy among two capacitors in a DC power supply of a pulse width modulated inverter which provides an AC output to a load. The bidirectional inverter circuit is responsive to a greater charge on one of the power supply capacitors than on the other to divert regenerative current flowing to the power supply from the load away from the one capacitor and to transfer charge to the other capacitor.
Claims13
In an inverter for providing an AC output to a load, the inverter having a DC power supply with positive and negative terminals and an intermediate reference terminal connected to ground, a first capacitor connected between the positive terminal and ground and a second capacitor connected between the negative terminal and ground, means for directing regenerative current flowing to the power supply from the load away from one of said power supply capacitors to transfer charge to the other of said power supply capacitors comprising:
- a bidirectional inverter coupled across said DC power supply for providing a first path for regenerative current between the positive terminal and the reference terminal of the power supply and a second path for regenerative current between the negative terminal and the reference terminal of the power supply, said bidirectional inverter being responsive to a greater charge on one of said capacitors than on the other of said capacitors to divert current away from said one capacitor through one of said first or second paths to said reference terminal, current flowing through said one path inducing a current flowing in the other of said paths to transfer charge to said other capacitor.
In an inverter for providing an AC output to a load, the inverter having a DC power supply with positive and negative terminals and an intermediate reference terminal, a first means connected between said positive terminal and said reference terminal for storing charge and a second means connected between said negative terminal and said reference terminal for storing charge, means for directing regenerative current flowing to the power supply from the load away from one of said first or second storage means to transfer charge to the other of said storage means comprising:
- a transformer having a first winding, a second winding and a tap therebetween, said tap being connected to said power supply reference terminal;
- first means for coupling the first transformer winding to the positive power supply terminal;
- and
- second means for coupling said second transformer winding to the negative power supply terminal;
- said first and second coupling means being responsive to a greater charge on one of said storage means than on the other of said storage means for diverting regenerative current away from said one storage means through one of the first or second transformer windings, current flowing through said one transformer winding inducing a current to flow in the other transformer winding to transfer charge to said other storage means.
In an inverter for providing an AC output to a load, the inverter having a DC power supply with positive and negative terminals and center tap, a first means connected between said positive terminal and said power supply center tap for storing charge and a second means connected between said negative terminal and said power supply center tap for storing charge, means for directing regenerative current flowing to the power supply from the load away from one of said storage means to transfer charge to the other of said storage means comprising:
- a transformer having first and second windings and an intermediate tap connected to said power supply center tap;
- first means for coupling the first transformer winding to said positive terminal and the second transformer winding to said negative terminal;
- second means for coupling the first transformer winding to said negative terminal and the second transformer winding to said positive terminal;
- means for controlling said first and second coupling means to alternately conduct current, each of said first and second coupling means, when controlled to conduct, being responsive to a greater charge on one of said storage means than on the other of said storage means to divert regenerative current away from said one storage means through one of said first or second transformer windings, current flowing through said one transformer winding inducing a current to flow through the other transformer winding to transfer charge to the other storage means.
Dependencies are inferred from the claim text.