VERY HIGH EFFICIENCY UNINTERRUPTIBLE POWER SUPPLY

• US 20120025609A1
• Filed: 09/22/2011
• Published: 02/02/2012
• Est. Priority Date: 09/22/2011
• Status: Active Grant

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: Renewable Power Conversion, Inc.
• Inventors: West, Richard Travis
• Granted Patent: US 9,203,323 B2
• Time in Patent Office: Days
• US Class Current: 307/31
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02J 9/063 Common neutral, e.g. AC input neutral line connected to AC output neutral line and DC middle point
• CPC Class Codes: H02M 5/297 for conversion of frequency
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements

Abstract

The invention is an electrical power conversion topology. The preferred embodiment is as a three-phase, on-line Uninterruptible Power Supply (UPS). The desired AC output voltage waveform is formed on each output line or phase of the UPS, using pulse modulation techniques and a smoothing output filter inductor. A semiconductor switching matrix is used to switch the power converter side of each output filter inductor between three voltage potentials, a positive battery potential, a negative battery potential and a third intermediate and varying AC potential synchronized with the desired output voltage. The invention potentially provides the same performance as that of a multi-level inverter topology approaching an infinite number of DC levels.

Claims

1. A power converter comprising an inductor, a positive DC input, a negative DC input, an AC input and an AC output, and further comprising a means of selectively coupling one of the three inputs to a first terminal of the inductor and where a second terminal of the inductor is connected to the AC output.

2. A power converter according to claim 1 where all inputs and outputs are referenced to a common neutral and where a load may be connected across the AC output and the common neutral.

3. A power converter according to claim 1 where said means of selectively coupling one of the three inputs is a semiconductor switching matrix operating as a single-pole-three-throw or SP3T switch.

4. A power converter according to claim 1 further comprising three of the power converters described in claim 1 and capable of conversion to three-phase AC potentials.

5. A power conversion method for converting power to a desired AC output potential to supply a load by using DC sources to selectively increase the stored energy of an inductor while supplying load current through the inductor and by using an AC source of similar, frequency, phase and amplitude to the desired AC output potential to in effect clamp the inductor voltage close to zero, and at the same time supply load current from the AC source through the inductor when said DC sources are not supplying inductor current.

6. An on-line uninterruptible power supply or power conditioner comprising an input rectifier, batteries and an output regulator as a means to convert an AC input source to and AC output source to power external loads and further comprising a means to source power directly from the AC input source, during a fraction of an output regulator pulse-width-modulation cycle, to an external load or loads.