Monopolar DC to bipolar DC to AC converter

• US 7,463,500 B2
• Filed: 01/03/2006
• Issued: 12/09/2008
• Est. Priority Date: 02/21/2003
• Status: Expired due to Term

• Current Assignee: Xantrex Technology Incorporated (Mission Critical Electronics LLC)
• Original Assignee: Xantrex Technology Incorporated (Mission Critical Electronics LLC)
• Inventors: West, Rick
• Primary Examiner(s): Ullah; Akm Enayet
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US11/306,580
• Publication Number:
  US 20080037305A1
• Time in Patent Office: 1,071 Days
• Field of Search: 363/56.01, 363/56.02, 363/95, 363/97, 363/98, 363/131, 363/132, 363/15, 363/17, 363/21.12, 363/37, 363/65, 363/71, 363/133, 307/45, 307/46, 307/48, 307/66, 307/71, 307/82, 323/247, 323/259, 323/268
• US Class Current: 363/132
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/0093 wherein the output is created by adding a regulated voltage to or subtracting it from an unregulated input
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

An electrical DC-to-AC power conversion apparatus is disclosed that is primarily intended for use with solar photovoltaic sources in electric utility grid-interactive applications. The invention improves the conversion efficiency and lowers the cost of DC-to-AC inverters. The enabling technology is a novel inverter circuit topology, where throughput power, from DC source to AC utility, is processed a maximum of 1½ times instead of 2 times as in prior-art inverters. The AC inverter output configuration can be either single-phase, split-phase or poly-phase.

Claims

1. An electrical power converter apparatus for converting power from a DC source into AC power and comprising;

a bipolar energy storage element having bipolar voltages with respect to a common point, a DC-to-DC power converter with inverted input and output voltages with respect to said common point and a DC-to-AC converter, and furthermore, where said DC source is connected across one monopole of said bipolar energy storage element and across the input of said DC-to-DC power converter and where the output of said DC-to-DC power converter is connected to the remaining monopole of said bipolar energy storage element and where said DC-to-AC converter converts the voltages across said bipolar energy storage element into current-regulated sine waves, synchronized with an electrical utility voltage or voltages, and sources power into an electrical utility grid.

2. The apparatus of claim 1, wherein the DC-to-DC power converter comprises a non-isolated flyback converter.

3. The apparatus of claim 2, wherein the non-isolated flyback converter comprises a transistor, inductor and diode.

4. The apparatus of claim 3, wherein the non-isolated flyback converter further comprises a current sensor.

5. The apparatus of claim 1, wherein one side of the DC source is grounded.

6. The apparatus of claim 5, wherein the connection into the electrical utility grid is split-phase, the apparatus further comprising first and second regulator circuits each associated with an AC circuit.