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US 5,270,913 AGranted
Compact and efficient transformerless power conversion system
AssigneeD.C. Transformation, Inc.
InventorRudolf Limpaecher
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AssigneeD.C. Transformation, Inc.
InventorRudolf Limpaecher
Estimating the term…
Disclosed is a new Transformerless Power Conversion System (TPCS) that allows a direct voltage step-up or step-down of DC or AC power without the use of magnetic core transformers. The operation is accomplished with solid state switching devices, capacitors, preferentially air core inductors and a switch control system. The conversion and step-up from AC to DC and the inverse process can be implemented with high efficiency and without the generation of harmonics. The transformer elimination in conjunction with high inversion frequency operation results in a low weight system without transformer core losses and third harmonic generation. For high ratio DC to DC transformation the TPCS transports the input charge directly to the output without requiring an AC link. The three distinct operations of charging, transformation, and energy discharge are typically in sequential order and allows a complete isolation between the input and output power grids. The TPCS allows complete power flow control and with it allows an improvement of power grid stability. A number of integrated TPCS modules can be configured to perform in a single system as a voltage transformation stage, a power converter or inverter, an output regulator, an AC phase angle corrector as well as a fast power interruption device. The architecture is specifically suited for high voltage DC power distribution systems with AC to DC conversion and step-up at the power station for HVDC transmission; DC to DC step down for DC distribution in place of AC; and final DC to polyphase AC power conversion near the bulk power consumers.
A transformerless voltage step-down transformation system comprising, in combination, (a) an electrical capacitor bank consisting of a plurality of series connected capacitors, (b) a means to charge this capacitor bank from a voltage source such that capacitors are connected with positive polarity to negative polarity in a series configuration, (c) means to electrically invert the voltage polarity of a plurality of the capacitors, (d) and means to conduct out the energy of the stepped-down voltage.
A transformerless voltage transformation system comprising, in combination, (a) an electrical capacitor bank consisting of a plurality of series connected capacitors, (b) a means to charge this capacitor bank from a voltage source many times a second, (c) means to electrically invert the voltage polarity of a plurality of the capacitors, (d) and means to conduct out the transformed energy.
A transformerless voltage transformation system comprising, in combination, (a) an electrical capacitor bank with a plurality of series connected capacitors, (b) a means to charge this capacitor bank from a voltage source, (c) means to charge the polarity of a plurality of the capacitors with unidirectional switching means, (d) and means to conduct out the transformed energy.
An electrical charge transfer device comprising, in combination, (a) an electrical capacitor connected in series with an inductor to form a series LC circuit having a resonance frequency of 1/.tau., (b) a plurality of switching means connecting a plurality of AC power sources to the series LC circuit to transfer energy from the selected AC power sources to the capacitor, (c) a plurality of switching means to transfer power from the capacitor to a plurality of selected loads, (d) and control means to control switching for the capacitor charging from the power source and capacitor discharging to the loads, wherein the control means operates the plurality of switching means for transferring energy to the capacitor to produce a sequence of resonance charging cycles, wherein each of said resonance charging cycles is of a duration of about .tau./2 seconds.
Dependencies are inferred from the claim text.