Compact and efficient transformerless power conversion system
AssigneeD.C. Transformation, Inc.
InventorRudolf Limpaecher
Life of this patent
Estimating the term…
Abstract
A transformerless power conversion system including a plurality of capacitors connected in series; a charging circuit connected to the plurality of capacitors, the charging circuit charging the plurality of capacitors from a voltage source to a predetermined voltage; a circuit for inverting the polarity of the charge stored in selected capacitors of the plurality of capacitors, the polarity inverting circuit including a plurality of inductor circuits, each of which can be switchably coupled to a corresponding different one of the selected capacitors to form a resonant circuit which aids in inverting the polarity of a stored charge in that capacitor; and a discharging circuit for extracting power from the plurality of capacitors at a transformed voltage.
Claims59
A transformerless power conversion system comprising:
- a plurality of capacitors connected in series;
- a charging circuit connected to said plurality of capacitors, said charging circuit charging the plurality of capacitors from a voltage source to a predetermined voltage;
- a circuit for inverting the polarity of the charge stored in selected capacitors of said plurality of capacitors, said polarity inverting circuit including a plurality of inductor circuits, each of which can be switchably coupled to a corresponding different one of the selected capacitors to form a resonant circuit which aids in inverting the polarity of a stored charge in that capacitor;
- a discharging circuit for extracting power from the plurality of capacitors at a transformed voltage and
- a control circuit controlling the operation of the charging circuit, the inverting circuit and the discharging circuit, said control circuit establishing a charging phase in which the charging circuit charges the plurality of capacitors, an inversion phase in which said inverting circuit to invert the polarity of said selected capacitors, and a discharge phase in which the discharge circuit extracts power from the plurality of capacitors, wherein a cycle of operation includes a charging phase, an inversion phase and a discharge phase, and wherein said control circuit causes said power conversion system to go through many cycles of operation per second.
A method of converting power from a voltage source, the method comprising:
- charging a plurality of series connected capacitors from the voltage source;
- inverting the polarity of the charge stored in selected capacitors of said plurality of capacitors;
- electrically coupling to said plurality of capacitors to produce a transformed voltage;
- extracting power from the plurality of capacitors at the transformed voltage;
- and
- repeating the afore-mentioned sequence of steps many times per second.
An electrical charge transfer apparatus for transferring charge from one phase to another phase of a multiphase power line carrying a AC signal having a period of T.sub.AC, said apparatus comprising:
- a capacitive storage circuit;
- a plurality of charging circuits each of which is for coupling a different phase of said multiphase AC power line to said capacitive storage circuit and to thereby transfer charge from that phase to the storage circuit, each of said plurality of charging circuits including a unidirectional switch and an inductor, wherein each of said charging circuits when coupled to said capacitive storage circuit forms a corresponding resonant circuit having a resonant frequency of 1/T.sub.i, where i is an index identifying the charging circuit and wherein the T.sub.i are all less than T.sub.AC ;
- a plurality of injecting circuits each of which is for coupling said capacitive storage circuit to a different one of said phases of said multiphase power line and to thereby inject charge from said capacitive storage circuit into the phase to which it is coupled, each of said injection circuits comprising an inductor and a unidirectional switch;
- and
- a control circuit operating the unidirectional switches of said plurality of charging circuits to produce a sequence of resonant charging cycles that transfer charge from one phase to said capacitive storage unit and operating the unidirectional switches of said plurality of injecting circuits to transfer charge from the capacitive storage unit to another phase.
Dependencies are inferred from the claim text.