Single-Stage Buck-Boost Inverter

Technology description

Renewable energy is coming to the forefront as global energy consumption is on the rise and our non-renewable resources are depleting. Energy from wind, solar, and tidal sources are essentially inexhaustible but the power output from these sources is generally sporadic due to the dependency on weather conditions.

This sporadic nature results in a wide range of input voltages which require an AC-DC inverter to convert the output into a fixed voltage AC output for typical single-phase loads in distributed generation systems. Current inverters address this issue but require five or more power semiconductor switches, with increasing costs per switch.

This invention details an improved single-stage buck-boost inverter. The inverter features a low number of power semiconductor devices, a simple circuit topology, and low power losses, which significantly reduce cost while increasing efficiency. The inverter utilizes a pair of coupled fly-back inductors to accomplish buck and boost operations for AC voltage control and allows a unidirectional power flow from the DC side to the AC side decreasing energy loss.

The inverter is well suited for small distributed generation systems, such as photovoltaic and wind for grid-connected applications, but is also useful for standalone purposes. The buck-boost inverter is particularly suited for applications that require 1 kW of rated power or below.

Advantages

The improved buck-boost inverter has several advantages over traditional inverters:

  • Simple circuit topology
  • Increased efficiency
  • Low number of power semiconductor devices
  • Low cost due to low component count, circuit topology, and low power loss
  • Best suited for grid-connected applications for distributed power generation
  • Suitable for applications using 1 kW of rated power or below
  • Output voltage control can be completed based on sinusoidal pulse-width modulation control

These advantages make the single-stage buck-boost inverter more beneficial and suitable for sporadic energy generation systems, especially for renewable energy systems such as solar and wind.

Stage of development


Lab prototype and tests have been completed.

Field demonstrations on engineering prototypes are needed to bring the technology to the stage of commercialization.

Intellectual property

  • Issued US Patent: US 7,333,349 Single-Stage Buck-Boost Inverter

  • Issued Canadian Patent: CA 2,502,798 Single-Stage Buck-Boost Inverter

This technology is available for licensing.

Contact information

Office of Research Services, Industry-Government Services
University of New Brunswick
Phone: (506) 453-4674
partner@unb.ca